Review of PaperWeek 2017 / J-FOR+ Vol.6 No.2 by PAPTAC

J-FOR

SPECIAL EDITION REVIEW: PaperWeek Canada & BIOFOR International

A PAPTAC PUBLICATION

JOURNAL OF SCIENCE & TECHNOLOGY FOR FOREST PRODUCTS AND PROCESSES VOL. 6, NO. 2

2017 PAPERWEEK

The Annual Conference of the Pulp and Paper Industry in Canada "Staying Ahead of the Curve"

CANADA

SPECIAL REVIE

W OF PAPTAC

BIOFOR International Montréal 2017

MAJOR EVENT

The International Conference for the forest-based Bioeconomy "Recognizing the Forest Fibre’s Value"

FEATURING A special section on the official coverage recap of PaperWeek and BIOFOR 2017 PaperWeek Executive Panel Discusses Twists and Turns Ahead of the Curve J-FOR’s Technical Papers with its unique blend of traditional and emerging topics

FOR THE ADVANCEMENT OF THE FOREST INDUSTRY

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Paper Advance

A PAPTAC PUBLICATION

TABLE OF

CONTENTS 5 EDITORIAL Greg Hay, J-FOR’s publisher

6 PAPTAC Communities CONFERENCE REVIEW SECTION

Executive Opening Breakfast Panel

PaperWeek 2017: Staying Ahead of the Curve

Executive Opening Breakfast Panel: Twists and Turns Ahead of the Curve

15 22 24

PaperWeek Conference Review

27 38 40

BIOFOR 2017 Conference Review

BIOFOR 2017 pointed out the future An optimistic bioeconomy panel kicked oﬀ BIOFOR 2017 Business Luncheons PAPTAC National Awards

TECHNICAL PAPERS

PAPTAC National Awards

Published by:

PAPTAC

Pulp and Paper Technical Association of Canada

For inquiries, please contact: PAPTAC 740 Notre-Dame St. W., suite 1070 Montreal (Quebec) H3C 3X6 CANADA Phone: (514) 392-0265

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Publisher: Greg Hay, PAPTAC Executive Director Co-editor: Stéphan Desjardins, Paper Advance Co-editor: Cristina Murciano, PAPTAC Production Specialist: Thomas Périchaud, PAPTAC

RHEOLOGY OF DISPERSIONS OF SPHERES AND CELLULOSE NANOFIBRILS by Leila Jowkarderis and Theo G.M. van de Ven

SOME PROCESS ASPECTS ON ACID SULPHITE PULPING OF SOFTWOOD by Raghu Deshpande, Ulf Germgård, Lars Sundvall and Hans Grundberg

THE IMPACT OF WET END CHEMISTRY ON PAPER MACHINE PERFORMANCE - FUNDAMENTALS REVISITED by Przem Pruszynski INDEX OF

ADVERTISERS

Kemira Kadant Solenis Andritz PulpEye Chesterton FPInnovations ICRC Buckman

Journal of Science & Technology for Forest Products and Processes: VOL. 6, NO. 2

02 04 08 14 21 26 37 65 66 3

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EDITORIAL

A PAPTAC PUBLICATION

PaperWeek and BIOFOR – the power of synergy Greg M. Hay, Publisher

We are pleased to be bringing you this special edition of J-FOR featuring the complete coverage recap of PaperWeek Canada and BIOFOR International, which took place this past February in Montreal. PaperWeek and BIOFOR welcomed over 900 participants and 40 exhibitors in 2017. A clear demonstration that despite the several conferences being organized around the world, the unique attributes of these two combined conferences remain a notto-be-missed Global Rendez-Vous in Canada for the industry to meet. Under PaperWeek’s theme “Staying Ahead of the Curve” and BIOFOR’s “Recognizing the Forest Fibre’s Value”, the two conferences presented world-leading programs covering the key aspects of forest products advancement and the new technologies being developed. The quality of the technical and business sessions of both conferences attested to the amplitude of the events and the undisputable reason of their success! The Sheraton Centre Hotel in Montreal, the new venue for this edition was up to par to welcome participants and accommodate the large number of presentation sessions and panel discussions. Informal gatherings and social events also contributed to provided attendees quality opportunities to grow their networks of contacts and foster their existing relations with peers. Renowned keynote speakers, actors which influence and lead our industry, took the floor during the daily kick-offs and business luncheons in order to share their views of the industry and give participants their take on what the future has in store. Furthermore, The Honorable James Carr, Minister of Natural Resources Canada, gave a forward-looking keynote to a packed venue full of eager listeners. We were especially pleased to hear one of the significant statements made by Minister Carr: “the industry is not just looking ahead of the curve, it is actually shaping it” – a comment that definitely resonates with industry’s resolve to remain competitive and where it needs to continue to grow. I am convinced more than ever that participating in PaperWeek and BIOFOR is an unquestionable investment both for companies and individual – a fruitful way to maintain and upgrade the required skills. As the value of the conference has remained the same for the past 103 years: to connect people and knowledge for industry advancement. In that respect, on behalf of the PAPTAC Executive Council, I take this opportunity to thank all of the many speakers, session moderators, program managers and loyal members, who provided indispensable support toward the success of these two events.

LEAD ASSOCIATE EDITORS Martin Fairbank Consultant Patrice Mangin CRML/Université du Québec à Trois-Rivières ASSOCIATE EDITORS Thore Berntsson Chalmers Institute of Technology (SWEDEN) Virginie Chambost EnVertis Inc. (CANADA) Christine Chirat Grenoble INP – Pagora (FRANCE) Jorge Luiz Colodette Federal University of Viçosa (BRAZIL) Ron Crotogino ArboraNano (CANADA) Sophie D’Amours Université Laval (CANADA) Robert Dekker (BRAZIL) Gilles Dorris FPInnovations (CANADA) Paul Earl Paul Earl Consulting Inc. (CANADA) W. James Frederick Table Mountain Consulting (USA) Ramin Farnood University of Toronto (CANADA) Gil Garnier Australian Pulp and Paper Institute (AUSTRALIA) Eldon Gunn Dalhousie University (CANADA) Ali Harlin VTT (FINLAND) Mikko Hupa Åbo Akademi University (FINLAND) Mariya Marinova École Polytechnique de Montréal (CANADA) David McDonald JDMcD Consulting Inc. (CANADA) Glen Murphy Oregon State University (USA) Yonghao Ni University of New Brunswick (CANADA) Ivan Pikulik Consultant (CANADA) Risto Ritala Tampere University of Technology (FINLAND) Reyhaneh Shenassa Metso Power (USA) Paul R. Stuart Ecole Polytechnique (CANADA) Trevor Stuthridge FPInnovations (CANADA) Honghi Tran University of Toronto (CANADA)

I wish all of you readers to be part of our next edition… See you in 2018!

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Journal of Science & Technology for Forest Products and Processes: VOL. 6, NO. 2

Communities connecting the right people

The PAPTAC Alkaline Pulping Community – Successful Restart!

Alkaline

The revival of the PAPTAC Alkaline Pulping Community during the summer of 2016 was long awaited and made possible thanks to the great leadership of Doug Barbour of Harmac Pacific, and Robert Dufresne of Resolute FP. Kraft pulping mills across Canada expressed the need to exchange best practices under a well-managed structure. PAPTAC used its tools and experience to set up and promote this group which now comprises over 60 representatives. It didn’t take long for the APC to get back on track, with a 1st webinar entitled “On-Line Kappa Measurement” in September and a 1st face-to-face meeting in October 2016, and both generating high attendance. Based on how this effective restart was, PAPTAC members can be sure to have a lot more coming in 2017!

The PAPTAC Bleaching Community is still on top of its game

Bleaching

The PAPTAC Bleaching Community has always been one of the strongest and most efficient work-group in the industry all around the world, and they kept doing their best in 2016 to offer members a unique forum for mutual support in daily operations. What strikes the most within this community is the constant and active participation of its members across Canada and the US, not only by attending face-to-face meetings in great numbers, but also by sharing and helping each other on a daily basis via their direct email Listserv. Problemsolving, training and on-line sharing has never been more easy and effective, and again in 2016, the Bleaching Community paved the way!

The rise of the PAPTAC Student Community – The Future Starts Now

Students

When PAPTAC created the Student Community, the goal was to build a path for the future workforce and forest companies to meet. These young graduates will soon enter the workforce as engineers, chemists, and eventually managers, and now is the right time to bring together students and their professors with forest companies, and prepare the future of our industry. Dynamic, tech-savvy, environmentally friendly, curious… All these characteristics reflect on the activities of the PAPTAC Student Community: informative sessions on the industry, regular feed on their PAPTAC Students Facebook page, or participation in annual science festivals to promote the industry. These passionate students will soon define our industry, and PAPTAC is proud to support the launch of their careers.

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Safety ﬁrst with Eastern Canadian Black Liquor Recovery Boiler Advisory Committee

ECBLRBAC

Recovery boiler safety is a must, and thanks to the ECBLRBAC – Network administered by PAPTAC since 2014 – Canada has its own group of industry representatives to look after safety of recovery boilers in our mills. Since PAPTAC took ECBLRBAC under its wing, the participants' base keeps growing at a good pace. Face to face meetings occurring once a year attract more and more mill personnel as the committee gains in popularity. The latest meeting took place in St John at the end of November 2016, which peaked with a tour of the Irving Pulp & Paper Chip Plant and their new digester. Participants were more than delighted with this activity, which will surely inspire the committee for the next meeting.

The PAPTAC Atlantic Branch builds on solid ground and sets the pace for other divisions

Atlantic Branch

Mills and representatives from Eastern Canada were the first to express the desire to revive a regional PAPTAC division in 2011, and what a growth since the return of the Atlantic Branch! The Atlantic Conference is now very well structured and attended, getting invaluable input from involved Maritime’s mills in order to set up a conference that addresses their specific needs. PAPTAC is very proud of the fast growing evolution of its Atlantic Branch, and particularly the fact that it sets the table for the revival of two other groups: the Western and Niagara Branches. PAPTAC member mills clearly expressed the need to establish regional networks. These three branch revivals are very positive signs for the industry!

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Journal of Science & Technology for Forest Products and Processes: VOL. 6, NO. 2

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SPECIAL EVENT REVIEW SECTION

2017 PAPERWEEK CANADA

www.paperweekcanada.ca

BIOFOR International MontrÃ©al 2017

www.bioforinternational.com

2017 PAPERWEEK CANADA

Staying Ahead of the Curve The PaperWeek Canada and BIOFOR International conferences

welcomed more than 1,000 participants and 40 exhibitors in 2017, who are demonstrated a commitment to this year’s theme of, ‘Staying Ahead of the Curve! For Greg Hay, Executive Director of PAPTAC, PaperWeek and BIOFOR were complementary events and served to reach and connect people interested in, and committed to, the future of the pulp and paper industry. PaperWeek’s new format, where conferences were grouped by specialty or topic, such as PulpEx, TechPack and Tissue Masters, was a huge success, Greg Hay as it allowed participants to tailor their own experience. "We are very pleased with the participation and have received excellent feedback on the quality of presentations and workshops," Hay reported. While BIOFOR is a stand-alone conference, it oﬀers many opportunities for synergy, and is expected to do so as it gains ground, importance, and helps foster interest in a burgeoning bioeconomy. The fact the federal government, as conﬁrmed by Natural Resources Minister James Carr, is targeting the sector to help it achieve its greenhouse gas reduction targets, only serves to underpin the point.

As several panelists also, Minister Carr underlined the historic importance of the forest sector, as we look to the future. "Not long ago, the forest industry seemed outdated,” he noted during the business dinner at PaperWeek. “But something remarkable has happened and it has become one of the most innovative sectors of our economy. The best chapters are still to be written."

Minister James Carr In recent years, PaperWeek Canada has also expanded its thematic content to include a broad array of topics focused on the business side of the industry, such as health, safety and management. These changes reﬂect the Association’s recognition of the shifting face of the sector. "These are key themes for our industry," said Greg Hay.

Eric Ashby

Sylvain Lhôte

Many of the sessions, workshops and panel discussions built on the theme "Staying Ahead of the Curve" demonstrate the concrete ways in which the industry has changed. Eric Ashby elaborated on this theme to note that an industry that focuses on bioreﬁning, as opposed to limiting itself exclusively to pulp and paper, is important. This assessment was supported by Sylvain Lhôte who noted the industry must also take advantage of a window of opportunity to decarbonize the economy, and to capitalize the uniqueness of its raw materials, which are able to capture carbon.

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The Annual Conference of the Pulp and Paper Industry in Canada

This year’s events also showcased the many ways in which other industries are showing an increasing interest in forestry as they seek to reduce their carbon footprints, as highlighted by Mena Salib, Manager, Aircraft Noise and Emissions, Corporate Safety, Environment and Quality for Air Canada. For Salib’s company, the solution to reducing reliance on carbon could be found in Canadian forests, if the industry is able to predictably produce the quantity and quality of jet fuel it requires.

Glenn Mason

Daniel Archambault

Mena Salib

The industry’s task now, is to investigate ways in which it can exploit these opportunities that exist in the aerospace, cosmetics, pharmaceutical, green chemistry, petroleum and other sectors. Many would suggest the key lies in the establishment of innovation clusters that draw in the expertise of multiple players across diﬀerent sectors. And so, with that, PAPTAC has an objective to work on for next year’s conference. We suspect it has already begun…

Minister Carr

Paul Lansbergen

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Donna Harman

Mena Salib

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TWISTS AND TURNS AHEAD OF THE CURVE

PaperWeek Opening Breakfast Panel

The 2017 annual conference of the Canadian pulp and paper

industry was launched with panelists from various horizons. All represent the diversity of the community present every year at PaperWeek Canada: company CEOs and key executives from North American companies, mill personnel, industry suppliers, academia and researchers. All are movers and shakers in the Canadian forest industry. Staying ahead of the curve… with eyes on the road After welcoming words and a description of this year’s conference theme: 'Staying Ahead of the Curve', moderator Catherine Cobden from Cobden Strategies introduced the panelists of the kick oﬀ panel: Glenn Mason, Assistant Deputy Minister, Natural Resources Canada; Sylvain Lhôte, Director General, CEPI; Ted Bell, Associate, PricewaterhouseCoopers and Eric Ashby, Vice President & Mill Manager, Domtar Windsor. The sector is facing stormy, unpredictable weather due to variables such as an uncertain political and economic climate south of the border. Of course, in relation to the recent Trump-Trudeau meeting, this will depend how the term “tweaking” will be interpreted in the context of NAFTA. Workforce Renewal Catherine Cobden asked about current threats and challenges for the Canadian forest industry. For Eric Ashby of Domtar, the

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challenge is to attract new talent. The situation in Canada is the same as the one in Europe according to Sylvain Lhôte: “we need chemists, algorithms experts, sustainability managers and so on and we need to educate youth accordingly”. Ted Bell invited participants to look into his firm’s most recent CEO survey. “Yes, exchange rate volatility and other economic concerns are important preoccupations but recruitment comes high on the list as well.” Glenn Mason agrees; for a science-based industry, a challenge is the aging population and the need for a younger workforce. Trade is an issue of importance and he cautioned we should all be concerned with a rise in protectionism. He recalled anti-dumping actions from China and countervailing duties coming from the United States as examples of this rising protectionism. To this challenge, Mr. Mason added an expected decline in access to fibre over the long-term. To overcome some of these challenges, an ever-broader corporate integration could be a solution: company mergers and acquisition across borders. Market Transformation Market transformation is clearly a trend said Mr. Lhôte, who explained that Europe has been preparing for this transition for decades. “We are good at offering recyclability and closed loop systems, and this is where we will continue to invest.” Mr. Lhôte invited participants to look at the new European industrial policy or the EU’s Commission bioeconomy strategy, which calls

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for the production of a set amount of recyclable biobased materials. How will the market meet the demand? Climate change policies is one of the important answers to the question, and some companies are already taking a leadership role in inﬂuencing or in responding to these policies. Sylvain Lhôte

Eric Ashby

Innovation and Sustainability Ted Bell believes the industry should find the best ways to couple sustainability with innovation. “We probably have to become more of a specialty-products based industry”. In this regard, “clusters of innovation should be formed between the forest and chemical industries”. Eric Ashby agrees, noting that “continuous improvement through innovation is key”. Participants concurred, yet noted there is a disconnect between what we observe with some front-running companies and leading research organizations and the majority of the pulp and paper community around the world. Panelists praised companies like Domtar for being responsive to new trends and took the opportunity of Eric Ashby’s presence to question why he thought his company was “doing the right thing.” To a question with no simple answer, Ashby proposed that finding the right people, with the ability and agility to adapt and identify opportunities were key components of the company’s success. “Companies shouldn’t wait for the government,” he suggested. “We should move forward and make many small bets – this could prove less dangerous that large ones”. Despite his strong belief in the capabilities of industry leadership, Ted Bell says there is sufficient evidence to suggest that authorities have to get involved. “Companies cannot do it alone.”

Glenn Mason

Ted Bell

Glenn Mason envisions that a dozen new forest products will enter the mainstream market and that biodiesel will be produced in large quantities in Quebec. “Why couldn’t we imagine the launch of a ﬁrst national bioeconomy strategy in Canada in which the forest industry would be one of the most important actors?” Participants were impressed by the optimism of the panel. The group of forest sector leaders engaged in dynamic discussions on key questions surrounding the future of the industry. “We are clearly shifting to niche markets and niche products,” summarized Catherine Cobden, “and this is light at the end of the tunnel.” Discussions are ongoing in the corridors of the conference venue. Undoubtedly, the conversation has just started and it started well!

Looking at the Next 5 to 10 Years Eric Ashby suggested those companies who will achieve success in a few years’ time will be those that have diversified, attracted new talent and developed an energized workforce. He further speculated that these companies will have also integrated a circular economy perspective into their businesses. “Traveling through Canada, we could envisage that we will not necessarily see traditional mills around us anymore but biorefineries, or bioproduct factories, for example”. “Our vision at CEPI is that our industries will be decarbonized by 80% in 30 to 35 years’ time,” said Sylvain Lhôte.“Being on the right path towards this could mean developing partnerships between countries and different regions of the world. It may look like science fiction but we can change the way we manage forest resources - this is what happened in Canada and around the world in just 15 years, why couldn’t we do this again?”

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Pulp EX The PulpEx Conference at PaperWeek

2017 Pulp Market Forecast The pulp and paper market grew 4% in 2016 and prices reached a ﬁve-year high. This good news is tempered, however, by the expectation that new mills will come into service later this year.

Basically, we should expect another market disruption for an industry trying to catch its breath, as demand for traditional paper products is not as strong as it used to be. “This spiral decline is powered by inspired consumerism in a digital age, where the new generation wants tailored products in real time,” said Paul Lansbergen, VP Strategy, Innovation and economics for the Forest Products Association of Canada (FPAC).

Fuelled by an increase in Chinese consumption and the low Canadian dollar, pulp prices in Canadian dollar terms reached a 6-year high, said Brian McClay, Principal McClay and associates, at the Pulpex conference kickoﬀ. Paul Lansbergen

Brian McClay “Price forecast is good over the next months and it can run hotter than people expect,” he said. “But reality will soon raise its ugly head because there will be too much supply.” That means that many mills will have to choose between closure, or conversion. Just to give an idea, a 2.8 million tons/year mill in Indonesia scheduled to open in 2016, should run at full potential sometime in 2017. Add to this a 1.3 million tons/yr mill in Finland and another 2 million tons/yr mill in Brazil. With all this new supply, the market will struggle in 2017 and plunge in the ﬁrst quarter of 2018, according to McClay. “Put your shin straps on, because there is going to be some mill closures or they will need to do something else rather than making pulp,” he said.

Paper Advance

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So where can the industry look to for growth and inspiration? “There are many opportunities with new products like CNC, cellulose ﬁbres, biochemical and biofuels,” added Lansbergen. With a constant rise in environmental awareness, the pulp and paper industry has a great opportunity to take action. “We have a great story to tell,” stated the FPAC VP. Basically, the future can be built out of biobased solutions, from jet fuel, to bioplastics and additives in metal alloys. It is also a solution when it comes down to our ocean polluted plastics, since 8% of those plastics is transformed into micro plastic particles that sink down into the ocean, and enter the food chain. This plastic could be replaced by rayon based products or bioplastics, says McClay. India’s growing market, an increase in e-commerce, growing packaging needs, and heightened demand for sanitary products in emerging markets will also drive market shifts. Even if paper consumption

continues to fall, fibre will still find its way into our houses. It will simply be in a different form.

Maintenance Shutdown Strategies Even in a situation where advancements in pulp production and technology are at their peak, the inevitability of shutdowns are critical budget line item for any mill or pulp and paper company. Being skilled at managing shutdowns is one way companies can better reduce downtime costs so that they don’t devour savings that have been achieved in other areas. Luckily, approaches to shutdown strategies are evolving and some presentations highlighted some of the latest developments in this field across Canada. Under the PulpEx umbrella, a panel discussion entitled, ‘Shutdown strategy approach (12/24/18 months),’ offered participants an opportunity to hear firsthand experiences and best practices in the realm of maintenance shutdowns, such as a scheduled down period in a plant for programmed upkeep that can last a significant period of time.

Eric Ashby Session Leader Eric Ashby, Vice President & Mill Manager, Domtar Windsor, welcomed and reminded participants that shutdown strategies can provide unique opportunities for a maintenance team, which aren’t typically available during standard operations. It is worth noting that substantial investments and planning are required for the proper and rigorous scheduling of these outages.

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Ryan Kazakoff Ryan Kazakoff presented the extensive experience of the single line NBSK pulp Domtar Kamloops mill, a single line NBSK pulp mill. He believes shutdowns must be treated with the recognition that they not only decrease the number of operating days at a facility, they also cost the sector a lot of money. Kazakoff noted that shutdowns “represent regular opportunities to re-invest maintenance budgets back into the mill”. In the case of the Kamloops mill, “shutdown budget and costs were not in control and complacency had crippled our shutdowns operations.” It became important in this context “to define and redefine how the mill prepares for and executes shutdowns and startups”. In this context, Ryan Kazakoff ’s team had to define what was new and what had never been done before to “redefine what worked but needed a tune up”.

Bob Ostaff Bob Ostaﬀ, Resolute Forest Products described the situation at Resolute’s Thunder Bay mill which encompasses three newsprint machines, two kraft mills, a sawmill, a waferboard mill and a wood yard. The mill underwent an 18 months shutdown cycle. The decision to aim for an 18 months

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period instead of a 12 or 24 month one was based on a multitude of factors explained by the Ostaﬀ. This led to a range of lessons that can be replicated for implementation in other plants across the country. Highlights of the shutdown strategy that ensued include the instigation of a shutdown planning group, organizing regular meetings with shutdown stakeholders throughout the cycle, shifting outages to spring and fall, aligning the outage with the work of the “woods group” or that of any other relevant team on a site, and expediting long delivery items. While the processes in place are still being reﬁned, reliability has improved and production risks have been mitigated.

Vincent Charbonneau Vincent Charbonneau is Maintenance Assistant Superintendent and Major Shutdown Coordinator at Domtar Windsor. He presented a new tool currently in use by the Windsor mill that assists managers in allowing them to better plan for an 18 month shutdown strategy. The tool is proactive and enables users to map out and plan shutdowns with a high degree of rigor and specificity so as to minimize financial impacts to the greatest extent possible. The tool, according to Charnonneau, accounts for the fact that, “human beings are creatures of habit who need to prepare well in advance for maintenance and shutdown activities”. The case of the Domtar Windsor mill illustrates that without wellplanned and performed shutdowns, equipment reliability suffers, employee moral takes a nosedive, and the mill pays the price in reduced quality and lost production.

TISSUE

MASTERS

Tissue Masters Conference

2017 Trends in Tissue Market In 2017, 83 new tissue machines will come online, churning out an additional 3 million tonnes of product per year. Should we expect market disruption, or new opportunities? Soile Kilpi, director, Poyry Management Consulting, expects long-term growth to remain at 3% globally, with most of it generated by Asia. Of the 83 new machines, a total of 50 of them will be installed in China – the bulk of them conventional in design. The only geographic location to demonstrate a diﬀerent trend, in fact, is North America, where TAD and NTT machines are producing softer tissue. More than 70% of the new machines themselves will be built by industry giants Valmet, Voith and Andritz. Encouragingly, Kilpi notes that quality continues to improve across the board. “We will see more private labels, bulk packaging and more decorative embossing coming,” she notes. “Also, more producers will need to integrate virgin pulp since recycled products are getting scarcer.” Cascades has made this integration a priority. “We are now into virgin ﬁbre and we want to be the most sustainable company doing it,” said Jean Jobin, CEO, Cascades Tissue. To meet the market’s need, Cascade recently built a mill in Oregon, to meet increased demand by a growing population in the southern and western parts of the U.S. “With this investment, we are now well positioned in the away-from-home market,” noted Jobin. Cascades Tissue is the fourth-biggest player south of the border, and second in Canada.

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Paper Advance

PAPERWEEK REVIEW industry.” The competition might be challenging, but steady growth promises a bright future.

Bruce Janda, Soile Kilpi and Jean Jobin To keep ahead of the curve, however, the company will require innovation to be at the forefront of its corporate agenda, a fact that Cascades is well aware of. “We used to innovate to meet clients’ needs,” Jobin reﬂected of his company’s past practices. “We now want to do our own innovation.” One of the ways the company is doing this, is by recognizing that the industry must constantly ﬁght an image problem amongst younger generations, such that pulp and paper isn’t necessarily considered ‘sexy’ by new talent. “We need to adapt to meet the new generation needs,” says Jobin.

TECHPACK

The TechPack Conference at PaperWeek

TechPack Conference Kick Off Moderator John Mullinder, Executive Director, PPEC welcomed participants to the TechPack Conference Kick Oﬀ by noting that, “containerboard is indeed a promising market segment, whether it is manufactured in North America or around the world.” In the highly anticipated session, experts discussed some of the most recent technological advancements in the ﬁeld, provided market updates and highlighted several recent and notable projects and technological achievements.

According to Bruce W. Janda, Consultant, Smithers Pira, change is accelerating. “North American consumers are different and they will continue to look for extreme softness,” he said. “This means the producer will continue to shift to TAD and NTT machines.” The patent for TAD technology has expired, which means it is now an equal opportunity playing field, notes Janda. “TAD is the most cost-effective tissue by case or square feet. More resistant than conventional tissue, TAD technology has the lowest resource cost weight and it yields the highest price per ton, all of this while increasing production by 10 to 20%.” Janda also expects consumer attention to shift away from recycled paper, while maintaining a strong interest on water consumption and fibre sustainability. “These disruptive times are also the most interesting ones,” Janda notes. Jobin agrees with this assessment, saying, “tissue making is a nice place to be in the pulp and paper

Paper Advance

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maintaining linerboard quality. Though, he did caution that the achievement of this goal requires both energy and the ability to “be the best in what you do”.

John Mullinder Mike Lafave, Senior Vice President & COO, Containerboard/Packaging & Recycling, Kruger, presented his views on the next generation of recycled linerboard. As Senior Vice President, Containerboard, Packaging and Recycling and a long career in the industry, Lafave is well-positioned to share insightful and thought-provoking assessments of the most recent technological advancements in the ﬁeld of lightweight packaging at Kruger. According to Lafave, the next generation of recycled linerboard and the path ahead towards successful production lies – simply enough – in producing at the lowest cost while

Mike Lafave It is easy to understand why companies all lean towards lightweight after we learn from Mr. Lafave that North America has 143 containerboard machines with a median age of 41 years and a median technology age of 19. At Kruger’s, mill in Trois-Rivieres, the shift to new technology materialized in a recent $250M investment to convert the No. 10 newsprint machine to enable it to manufacture 100% recyclined lightweight linerboard. Lafave explained that Kruger likes to think of “rightweighting” as a differentiation strategy from those who speak of “lightweighting” - an important nuance for a company that markets itself as a forerunner in the next generation of containerboard producers. Donna Harman, President, American Forest & Paper Association (AF&PA) discussed recent trends in the sector and presented the Association’s positions on the economic and political context two months into 2017. The specific focus of Ms. Harman’s presentation was on the meaning of the recent 2016 US election for the North American containerboard and corrugated industry. Harman identified international trade issues, a possible comprehensive tax reform in the United States, infrastructure and transportation efficiency, federal regulatory reform and developments in the recognition of the carbon neutrality of biomass, as critical issues facing the sector.

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“We are in a time of global political and economic disruption,” noted Harman, who recalled recent protectionist trends around the world. This does not affect bilateral trade opportunities between Canada and the United States but certainly calls for the industry’s attention. “There are already 14 billion dollars’ of commercial flows between our two countries.” In the perspective of AF&PA “U.S. paper and wood product manufacturers need unrestricted access to international markets” and as such, the organization continues to push for a level playing field with international competitors through the elimination of trade barriers. AF&PA also underscored the importance of working towards collaboration with the new Administration in the U.S., as Harman noted, “we share the same goals of growing the economy.”

Donna Harman Changing hats for that of a panelist, moderator John Mullinder, Executive Director, PPEC, introduced the work of the PPEC or “Paper and Paperboard Packaging Environmental Council of Canada” in a presentation entitled ''Sustainable, green packaging – advancements, trends, market perspectives – cutting through the greenwash!'' John Mullinder explained that “PPEC is a national trade association representing the Canadian paper packaging industry on environmental issues with a membership that includes paper mills producing containerboard, boxboard, and kraft paper packaging grades and the converters who turn this into corrugated boxes, paper bags and sacks, and boxboard or paperboard cartons”. 18

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Particulars on packaging in Canada were listed including the fact that most boxes and cartons fabricated in Canada are 100% recycled content. Mullinder also addressed the gradual pan-Canadian ban on the disposal of OCC in public landfills, noting that Nova Scotia and PEI have demonstrated themselves to be leaders in this domain. “PPEC has a 26-year track record of environmental leadership, including several world or North American firsts,” noted Mullinder. “For example, back in 1990, cereal and shoe boxes went straight to landfill. Working with its customers and municipalities, PPEC coordinated mill trials that today mean that virtually everyone in Canada can recycle these boxes.” Clearly, for Mullinder, despite advances towards a sustainable packaging recycling system in Canada, the product itself is one of the most environmentally friendly there is. “Unlike most other packaging materials, paper packaging is originally made from a renewable resource — trees and trees are certainly not a bad thing for the environment.” With this in mind, we can hope that the more educated consumers will be on greener forest and non-forest products, the brighter the future will be for pulp and paper companies.

ENVIRONMENT SESSION When going green yield results Working towards environmental sustainability has been a challenge for the pulp and paper industry for a long time. The hard work is now paying off, as over time, the industy has positioned itself as a leader and is pulling in profit from byproducts. From 1990 to 2012, the pulp and paper industry successfully reduced its greenhouse gas emissions by 66%, James Carr, the Minister of Natural Resources confirmed during his speech. Had all industries

have achieved similar goals, Carr noted, we would not have occasion to discuss the Paris agreement in Canada, because we would have already met our targets.

Fewer toxins, more fish Toxins released in the environment generated significant concern in the 1980s, recalled Pierre Martel of FPInnovations. At that time, chlorinated dioxins and furans were having toxic impacts on many organisms such as fish and other biota. When the effects were discovered, regulations were enforced and industry responded rapidly.

Pierre Martel Regrettably, many of these improvements did not allow fish populations to recover, as effluent treatments continued to wreak havoc on their habitats. In response, the Environmental Effects Monitoring Program (EEM), a cohort of industry, government and research officials, was established with a mandate to investigate what influenced fish reproduction and fish communities. The results of a survey that looked at more than 81 types of effluents, generated by 20 mills, was conducted. “The only significant relationship we could find was biochemical oxygen demand (BOD), which is directly linked to the amount of organic content in the water,” Martel noted. These results made the process of tailoring a solution an easy one: Mills needed to reduce the amount of organic material they released. Basins were installed, and did not require significant investment or technology. “The solution was simple,

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PAPERWEEK REVIEW but we had to demonstrate the source of the problem before taking action,” Martel noted, suggesting that collaborative research still works well after the 8th EEM cycle.

Can ash become an asset? In the 1990s 90% of the ash produced in pulp and paper mills was going to landﬁlls. Today, this number has been reduced, but we still throw away more than 65% of ash, says Talat Mahmood, researcher at FPInnovations. “Landﬁlls are costly and ashes can create environmental hazards down the road. We can do something good with it,” he said.

RELIABILITY SESSION

MANAGEMENT SESSION

Water waste improvement show big returns

Bridging the GAP between Strategy and Execution

What does water waste cost at your mill? Reducing it could translate to hundreds of thousands of dollars in annual savings. Water is needed to produce paper. But it can also translate to many costly problems. While the main costs are not driven by the presence of water itself, the need for reheating, the evaporation process and excess ﬂow, can all lead to a hefty and unexpected price tag for a mill, Stephen Folk, North American market manager for AW Chesterton, noted.

Talat Mahmood To increase the value of ash, the two main components should be separated, suggests Mahmood. (Note: ash is made of small white particles (inorganic particles) and bigger char particles (unburned carbon). Char particles could be activated to create activated biochar, which could then be used as an energy source or spread over farmlands or forest. Inorganic material can also be used in the agricultural sector, for supplementary cementing material or road stabilization. This change of mentality could create value instead of being a burden for the mills, concluded Talat Mahmood.

Stephen Folk It logically follows, then, that it can become very expensive to heat water that you don’t even need. AW Chesterton tested water costs at five separate sites to determine that costs can vary as much as the difference between 100,000$/yr and 784,000$/yr. On average, a mill consumes about 400,000$/yr. Helpfully, these costs can be reduced by as much as 80%. AW Chesterton conducts ultrasonic surveys to measure water and energy waste. By assessing which equipment consumes the most energy, Chesterton helps a mill determine which upgrades could translate to significant savings.

In a presentation entitled ''Bridging the GAP between Strategy and Execution'', Jacques Woods, President and founder WONpager Strategies, described a pragmatic approach to making vision a reality. The management consultant explained that, following 22 years of experience with large companies such as Kraft, Imasco, Culinar and Bombardier, he is well positioned to help management learn the art of consensus building and to develop strategic vision, key strategies, and accountability mechanisms. Woods stressed the importance of what he calls, ‘disruptive thinking,’ a process he suggests, ‘may create magic.’ Oﬀering a tested list of basic rules to follow when seeking to transform a simple strategy into business performance, Woods outlined the importance of: “Keep it simple, make it concrete; Debate assumptions, not forecasts; Use a rigorous framework, speak a common language; Discuss resource deployments early; Clearly identify priorities; Continuously monitor performance; Reward and develop execution capabilities”.

Jacques Woods While the area of how to materialize good business ideas is one that has been much explored, Woods is of the mind that human strengths and weaknesses should be top

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2017 PAPERWEEK CANADA

of every manager’s list of considerations when it comes to implementing successful teams. He underlined the importance of holding true to one’s vision, and that soul searching is very often a necessary step in achieving concrete results. Suggesting the ancient Greek aphorism ‘know thyself’ be applied in all strategic planning attempts, Woods noted that strategy involves a very clear assessment of who we want to be, and then taking direct steps towards attaining that self-visualization. Woods, tongue-in-cheek suggested that Steve Jobs was likely to have asked himself what he wanted Apple to be as a company, instead of focusing exclusively on the goal of trying to win over market shares from Bill Gates. Woods also shared his WONpaper software, which was designed for the management of strategic plan commitments and action points. The application serves as a tool that “enriches and facilitates planning development, deployment, communication and follow-through process via one page summaries.” Using the real-time case study of a large business based in Quebec, Jacques Woods certainly stimulated the interested of managers in the audience.

BLEACHING SESSION For the Love of Bleaching

suppliers and consultants, who share a common interest in the bleaching of chemical pulp.

Daniel Brouillette Mona Henderson of Valmet, gave the morning’s first presentation, which focused on the downstream impacts of digester operations. (Henderson, notably, is the most recent recipient of the Howard Rapson Award). A chemical and process engineer, Henderson outlined how digester operations can not only impact downstream operations, but can also affect the quality of a final product and drive up the cost of producing pulp. Her presentation focused on the factors to be considered when seeking optimization of the fibreline in terms of yield, final pulp quality and operating costs. These factors are particularly relevant as today’s operations must be competitive in multiple domains to remain commercially viable. Maintenance of ideal chip size, the avoidance of pin and fines, the removal of all air from chips (pre-steaming) and the regulation of the chemical profile in digesters were all offered as keys to good operation.

The PAPTAC bleaching community assembled on Valentine’s Day at PaperWeek Canada! Love IS a chemical process! Chlorine and Sodium hypochlorite forever! Daniel Brouillette of GLV, introduced the bleaching session and welcomed participants as they settled in to listen to presentations on some of the latest scientiﬁc research developments in the ﬁeld. PAPTAC’s bleaching community is comprised of a diverse group of pulp and paper industry representatives, as well as mill researchers,

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can be achieved through an emphasis on people skills, focus and motivation, or, as he described, “with brainpower and without the need for new materials or technologies”. The main challenge, suggested Côté, is the need to convince teams to focus on bleaching costs and performance indicators. Also a chemical engineer, Côté, identiﬁed key points for improvement. One of the suggestions oﬀered concerned the stabilization of tonnage target.

Dominic Côté

Thanh Trung, FITNIR Analyzer Inc. presented his team’s work on the application of online measurements and control for pulp and paper operations. His discussion, entitled, “ClO2 Generator Optimization And Control Traditional And New Measurements Tools,” included an overview of ClO2 generator chemistry and the importance of chemical compositions for efficient operations, with an emphasis on learnings and best practices. A notable conclusion of this research is that automation can lead to strong financial incentives, while improving operational safety. The importance of manual testing of acid and ClO3 which “must follow standard procedure to ensure accuracy and allow sufficient time for solids to settle before pipetting,” was highlighted as a best practice.

Mona Henderson In a presentation entitled ''Chemical Cost Reduction in 50F Bleach Plant'', La Tuquebased Dominic Côté, Westrock delivered a robust description of how eﬃciencies

Thanh Trung

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BIOFOR International Montréal 2017

BIOFOR 2017 pointed out the future For 103 years, PaperWeek Canada has served the international

pulp and paper industry as a unique forum for discussion, knowledge exchange and growth. This year additionally marked the second oﬀering of BIOFOR International as a companion event. James Carr, Minister of Natural Resources Canada, was a guest of honour, and repeatedly signalled the government’s commitment to the industry.

BIOFOR Kick off Panel BIOFOR 2017 showcased the multiple opportunities for transition the pulp and paper industry currently has at its oﬀering. While for many years the sector has been devoted primarily to the development and modiﬁcation of production practices, increasing productivity and developing new paper and board products, there was widespread recognition that forward thinking is critical. As Glenn Mason, Assistant Deputy Minister at Natural Resources Canada cautioned, “paper will not carry us through the next hundred years!”

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This was also a theme that Minister James Carr stressed in his luncheon speech to PaperWeek and BIOFOR 2017 participants. The Canadian government is well aware of Minister Carr the importance of the Canadian forest industry and Carr noted that government will support every stage of the development chain, from idea to market, to facilitate the transition to a sustainable bioeconomy. Once again underlining his government’s support, Minister Carr concluded his speech with the reassurance that; “we ﬁght together with you, shoulder to shoulder”. The program covered a wide range of topics related to the bioeconomy, ranging from research projects such as, “Designing kraft lignin based dispersant for clay suspension” to bio products produced in demo and full-scale plants. As most potential bioeconomy products are aimed at replacing oil as raw a material, it comes as no surprise that the new bio-based products are no longer limited to the traditional forest industry value chain, but will enter a number of new ones along the way. A number of speakers noted throughout the week that companies will need to focus their eﬀorts on a limited but strategic number of developments to concentrate their expertise and maximize results.

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The International Conference for the forest-based Bioeconomy

As participants heard, one possible new value chain for the forest industry could be bio jet fuel. Mena Salib, Manager Aircraft Noise and Emissions at Air Canada, held a luncheon speech in which he presented IATA’s, and in particular Air Canada’s, clear ambition to reduce emissions. Apart from using more energy-eﬃcient aircrafts to reduce fuel consumption, there is a clear opportunity for the forest industry to supply the industry with bio jet fuel as a drop-in fuel. While the requirements will be stringent and the forestry industry would have to be able to guarantee a stable supply at a competitive price, the beneﬁts are worth it: Just 1% of Air Canada’s fuel consumption in 2014 was 42 million litres.

BIOFOR International Montréal 2017

For the first time, BIOFOR 2017 also contained a one-day workshop on 3D printing. Experts from North America and Scandinavia provided a number of interesting and futuristic presentations. The opportunities for 3D printing using a mixture of cellulosic and plastic feedstock are significant and applicable to a wide array of applications. While most are in the research stage, participants heard firsthand about developments in this arena. The technology is in its infancy and to drive development it will be important to find suitable applications for projects that can generate volumes of sufficient size to be profitable for the forest industry.

BIOFOR International has clearly earned its place as an integral part of PaperWeek going forward. It eﬀectively identiﬁes future opportunities and directions for the international forest industry and creates a winning platform of research, industry and discussion of cutting-edge technology that will serve as a critical guide for the forest industry’s transition to the bioeconomy. While traditional products such as packaging materials, tissue products, and yes, even paper, will be an important part of all our lives for the foreseeable future, innovation is upon us, and it is much needed.

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An optimistic bioeconomy panel kicked off BIOFOR 2017 The valley of death, the need to move faster, recruiting the

right talent and succession planning were some of the elements discussed in the Biofor kick-off panel by five highly-qualified industry, business & technology development, government and research representatives. The panel discussion was led by Jean Hamel, FPInnovations. The invited panelists were Glenn Mason, Assistant Deputy Manager, Natural Resources Canada, David C. Boulard, Executive Vice President, Ensyn, Daniel Archambault, Executive Vice President, Kruger Inc., John Kettle, Vice President Sales and Business Development, VTT Technical Research Centre Ltd and Mike Rushton, COO, Fibria Innovations. In his introductory remarks, Jean Hamel noted that some of the first bioeconomy products such as biochemicals, biofuels and biomaterials are now reaching market, but many other products and technologies are still being developed. Transformational activities are taking place in the Canadian forest industry, and through trial and error, industry is learning and growing. That said, we need to be mindful of the ways in which companies can optimally adjust their business formulas. Transition may be well in the saddle, but to move forward, we need to consider not only how to calibrate, but at what speed. Participants were asked to consider their own perceptions of the bioeconomy. “It is very early days still in reality”, said Mark Rushton. “It is mentioned in annual reports but has not yet materialised in a large scale. In reality we have a long way to go”.

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PaperWeek Opening Panel “Compared to us theBreakfast Nordic countries have come a bit further”, John Kettle continued. “The piloting part of development activities to form a base for future industrial production is what’s needed now. Metsä Fibre’s new concept ‘bioproduct mill’ is inviting other companies to establish production within its industrial complex. This is one example of a trend for the forest industry to develop into new business areas”. “In Canada we are not moving fast enough in this area”, Daniel Archambault cautioned. “The risk is that we miss future opportunities so we need to ﬁnd a way to accelerate the development. There have to be incentives to speed it up and there must be a reward to the industry. The low price of oil is a risk for a number of potential bioproducts”.

“Success breeds success”, stated David C. Boulard. “Our company, Ensyn, has now come out of the valley of death and our RTP technology is used in a full scale plant producing bio crude used as one component in diesel production. There is more interest in ‘green’ issues and regulations and this oﬀers us an opportunity to introduce new, environmentally-friendly products. Once we have secured a market, buying big and regular volumes, we can ﬁne-tune production and logistics processes and bring our costs down”. “The bioeconomy is here but in no way is it here on the scale it is in Europe”, Glenn Mason added. “We need to be quicker in all sectors being it public, academia or industry. Our forest resources will play a key role in the transition to a bioeconomy. Questions we should ask us are these. What would make Canada a good

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BIOFOR Kick Off Panel

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place for the bioeconomy? Do we have a tax structure that favours development? A number of Canadian companies are now investing in development and production of bioeconomy products. From our perspective we wouldn’t have needed the Copenhagen agreement as we are already there. The issue now is not to lose the momentum!” “Key drivers have to be there to create a pull for the development,” Daniel Archambault stressed. “Kruger is a big producer of commodity products and we entered a development project aiming at producing cellulose ﬁlaments, which was a technical success. It is a totally new and high value area to us. We are now in a situation to pass the valley of death and for that purpose we need to bring in new people with new ways of thinking. So in a traditional industry we must ask of ourselves, ‘how can we open new markets without new people?’” “Another challenge is to get the capital required to get into this sector”, Mike Rushton pointed out. “This is very true of markets which are not fully developed. Investors are often living by the ‘better safe than sorry’, rule and put their money in established technology for existing products”.

Jean Hamel

At the end of the Biofor Kick-oﬀ panel the panelists shared their views and hopes for how far the transition towards a bioeconomy will go. Some of the highlights included; The pace of transformation will accelerate. The macro economy will motivate everyone to go in this direction. Partnership is a strategic issue and a necessity. We will look back and say that we have passed the crossroads and gone for the bioeconomy. Certain parts of the industry will be falling down but others will grow. Certain products from the forest industry will be niche products and very valuable. The growth will be rapid. Market pull will be created and attract more companies to invest. New technologies will come. The panel discussion clearly showed that the forest bioeconomy is deﬁnitely moving forward, although it has to be at a higher speed. There is still a lot to be done, not least when it comes to bridging the valley of death bringing new products based on renewable forest raw materials to market in competition with corresponding oil based products.

Glenn Mason

Daniel Archambault

David Boulard

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John Kettle

Mike Rushton

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BIOFOR INTERNATIONAL REVIEW

BIOFOR International Montréal 2017

Market Development Government Initiatives & Programs Focus on cooperation, value added and to link arms with other business sectors How can government initiatives and programs support the development of a robust bioeconomy sector in Canada? In the fall of 2017 the Forest Bioeconomy Framework for Canada will be presented, forming a platform of diﬀerent proposals to support the transition to a bioeconomy. In that framework cooperation between all parties is a necessary prerequisite for a successful Canadian bioeconomy. The panel discussions were led by Paul Stuart, Principal Consultant at EnVertis. The panel itself consisted of Glenn Mason, Assistant Deputy Minister, Natural resources Canada, who had a busy day participating in three diﬀerent panels. It also featured Murray McLaughlin, Advisor, Bioindustrial Innovations Canada, Warren Mabee, Canada Research Chair in renewable energy development at Queen’s University and Paul Lansbergen, Senior Vice President, FPAC. Warren Mabee noted there are two big drivers behind the bioeconomy development. Canada’s need for economic development and industry growth, and global

warming. To this regard, a focus on how to use biomass, and for which applications, is important. The Canadian energy sector, which exports 1/3 of its energy to the U.S., is significant, and a large contributor to the economy. The question now is, how do biomass energy products incorporate themselves into the bioeconomy in a profitable way? In Sarnia, ON, a bio-based industry is growing around the already developed petroleum industry, which once dominated the region. Murray McLaughlin gave an engaging talk which stressed the importance of understanding where bioproducts fit into today’s existing petroleum-based value chains. While bioproducts will not be able to replace every petroleum-based counterpart, identifying specific applications offers an opportunity to find product areas with cost-savings advantages when compared to oil as a raw material. Glenn Mason expressed his strong belief in the potential of a Canadian bioeconomy. The forest industry has been a building block of Canada’s economic power for 150 years and will continue to be so, if the opportunities within the bioeconomy are fully explored, Mason suggested. He committed that the Canadian government will support every stage of the development chain, from idea to market, to facilitate

the transition to a sustainable bioeconomy. Fibre supply is an issue, however. One reason for this is that the majority of the population lives in the south, and is far removed from large forested areas and is unaware of the sustainable options available to exploit Canada’s forests. To address this, the panellists agreed on the necessity to inform and communicate the great opportunities for a more sustainable society by using the forest resources as a way to combat global warming, while creating jobs. The importance of cooperation was repeatedly stressed during the panel discussion. International cooperation, over different industry borders and across different sectors, was noted as an opportunity. The time has gone when the forest industry only cooperated with itself. In this sense, the forest industry has to re-invent itself and the way, and with whom, it works. The last part of the panel discussion focused on which kind of jobs the bioeconomy will create. It will not be as labour-intensive as the forest industry was once upon a time. Production plants will increase in efficiency as markets grow and reliance on modern technology replaces much human labour. However, jobs will generate in the domains of harvesting and supplying raw materials, research and modern production technology, and these and other opportunities will offer young talent exciting challenges in the industry. The panel had some prescriptive last words, noting that it will be more important to focus on high value products and not necessarily measure the volumes in tons. The focus should be on value-added products in order to get the most value out of the wood resources.

Glenn Mason, Murray McLaughlin, Warren Mabee, Paul Lansbergen and Paul Stuart

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Research Leading to Market Moderator Catherine Cobden of Cobden Strategies welcomed a room full of participants by asking the very same questions that guided conference organizers in their preparation of the session. ‘What recent trends are crucial to identifying avenues to market development’? While we take for granted that research leads to new markets, and that the work undertaken by research institutes has repeatedly proven this, how can we answer the question of how markets successfully adapt to a changing industrial reality, and how can industry benefit from the forest bioeconomy? Trevor Stuthridge, Executive Vice President, FPInnovations provided an overview of the projects FPInnovations has been working on in recent months, and highlighted the directions current research is leading. “The organization’s overarching strategy is to foster industry partnerships,” Stuthridge said. The institute has successfully added value to the market by introducing forestderived bio-products, such as Neste and Bioenergy La Tuque research and development cooperation, as well as it’s involvement in the world’s first cellulose nanocrystals plant, the world’s first cellulose filament plant and Canada’s first lignin separation plant.

Trevor Stuthridge In a presentation entitled “A CelluloseBased Society”, Marco Lucisano, RISE Bioeconomy/Innventia, examined the trends

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that are aﬀecting the role of the forest industry in providing innovative, renewable materials based on cellulose, and the new business models they’re relying on to do it. Lucisano highlighted results from the Innventia International Consumer Survey, in which consumers were asked to imagine and react to the idea of “a future in which resources from forests are used to create an array of products – everything from textiles and vehicle parts to cosmetics and prosthetics.” The results were surprising. Some respondents indicated that biobased materials are considered not as ‘reliable’ as so-called ‘natural’ ones. This ﬁnding in particular fed into a broader discussion of trends and perceptions. That society is becoming increasingly urban and distant from nature, is a prevalent trend.

World L-S Nieh P3Nano, a public private partnership formed by the U.S. Forest Service and the U.S. Endowment for Forestry and Communities, issued a second round of request for proposals (RFP) in 2016 totaling US$2.25 million. The partnership is evaluating 64 proposals totaling US$18 million in response to the RFP. Other United States initiatives were discussed, including the Bioeconomy Initiative, the National Network for Manufacturing Innovation and the National Nanotechnology Initiative.

BioAmber sales ramping up

Marco Lucisano In a presentation entitled “Innovations in a Forest-Based Bioeconomy” World L-S Nieh, National Program Lead, U.S. Forest Products Labs, outlined why it is expected that future societies will rely heavily on forest products, particularly those composes of cellulose nanomaterials, which are just ﬁve years away from commercialization in the U.S. Renewable polymers were also discussed, and are expected to achieve commercialization in the next decade. “According to a Lux Research study, the time from ideation to full commercialization for new technologies whether we are talking about information technologies, biotechnologies or nanotechnologies is 30 years,” noted World L-S Nieh.

The Canadian bioproduct industry is gaining momentum, as demonstrated by the quadrupled annual sales of biochemical plant BioAmber. “We are basically a producer of bio-succinic acid,” said Laurent Bernier, Senior VP Compliance and Administration of the 30,000 ton per year facility. “We produce the same sugars the oil industry does, but we use corn instead”, said Bernier. Succinic acid is actually the building block of many other chemicals.“ “The beauty of this molecule is that it offers a unique platform that allows for the production of variousvery useful products or by-products,” Bernier explained. “For example, succinic acid can be used to produce different chemicals that go into plastics, food, corrosion inhibitors, personal care and many other applications. We find it in most living cells and humans produce it as well.”

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BIOFOR INTERNATIONAL REVIEW

For a product looking to break into this commodity market, however, the biochemical must be a ‘drop-in,’ meaning it is readily able to replace its conventional chemical counterpart. For some applications, the bio-succinic acid has enabled the development of new opportunities, such as those found in better UV protection now found in paints.

Laurent Bernier To make the process cost-effective, the other magic ingredient is a prolific strain of yeast, the bacteria that can transform cornstarch into sugars. “We worked with Cargill to improve the yeast capabilities to produce succinic acid. We now have a very robust and productive strain, ”said Bernier. While a ‘green’ chemical is a good option, it needs to be cost-effective for the client, cautioned Bernier. BioAmber appears to have locked onto a winning formula, for its sales have increased to $3.7M in the third quarter of 2016 – up from $1.1M in the last quarter of 2015. In the near future, BioAmber hopes to build a second biochemical plant, either in the U.S., or in Sarnia, ON. For that venture, the company wants to use non-food biomass— agricultural or forest waste—as a source of sugars. Funding and tax incentives will be significant factors in landing on a geographic location. Looking even further down the road, the company has its eyes on the production of succinic acid from industrial methanol, or methane, out of a chemical plant.

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Towards a Forest Bioeconomy Framework for Canada There were a number of good ideas discussed in the session dedicated to discussing the transformation of Canada into a recognized global leader in the forest bioeconomy, and one of them was the establishment of a Forest Bioeconomy Framework. As the Honourable James Carr, Minister of Natural Resources, noted, over the last few years, the Canadian Council of Forest Ministers (CCFM) has made innovation one of its top priorities. In fact, the CCFM recently endorsed Canada’s Innovation Action Plan, which recognizes the critical importance of federal and provincial/territorial cooperation. Moderator Glenn Mason, Assistant Deputy Minister, Natural Resources Canada welcomed participants to the session, where experts were asked to discuss a bioeconomy framework in breakout groups under the theme of: ''Facilitated dialogue on the key elements of the draft CCFM Framework''.

Glenn Mason The first presentation, entitled ''Regional Collaboration to Support Forest Sector Innovation'', was provided by André Denis, Director General (Quebec) of the Wood Innovation Forum. Denis described the organization’s role and those of its five forces on saw mills; bioenergy; wood burning; panels; pulp, papers and bioproducts. While each task force deals with issues specific to the industry it represents, common themes and concerns run parallel to

all five, such as the public’s perception of the industry, and the renewal of manpower. In an effort to address these issues, 39 measures were identified along four basic themes of innovation, modernization, regulation and the business environment. With regard to next steps and opportunities, Denis said he believes the “turnaround is well initiated and that there is light at the end of the tunnel”. Companies are demonstrating engagement and the forum provides an entry point for the Government of Quebec to engage with industry. It is critical, Denis noted, the federal government remain an important in relation to finding sustainable solutions to the softwood lumber dispute.

André Denis Kathleen McFadden, Assistant Deputy Minister at Ministry of Natural Resources, Ontario, provided an overview of the Canadian Council of Forest Ministers (CCFM) Forest Bioeconomy Framework for Canada'. The mission of the CCFM is fourfold: Promoting cooperation between governments Developing and maintain a scientiﬁc information base Demonstrating international leadership Sharing information on issues impacting on the forest sector This mandate was underpinned by the CCFM’s recent release of its Innovation Action Plan for 2016-2020. In an overview

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of the framework’s key elements, Ms. McFadden explained the Bioeconomy Framework is thought of as “a non-binding commitment among CCFM partners that provides a clear vision, identifies common priority areas, and outlines a comprehensive suite of policy actions for creating a more effective enabling environment to grow Canada’s forest bioeconomy.” Despite the complex nature of moving policy into the realm of concrete action, McFadden asserted this does not detract CCFM partners from a common vision of positioning Canada as a global leader in the forest bioeconomy. “In this context, the ‘bioeconomy’ rests on the principle of the search for efficiency whereby forest resources can be “managed in a sustainable manner adding maximum value, including by reusing materials to preserve natural capital stocks, and respecting the services and cultural value they provide to support the well-being of Canadians,” McFadden noted.

What is your vision for Canada’s forest bioeconomy? What do you think are the biggest barriers facing the advancement of Canada’s bioeconomy? What are your thoughts on the proposed CCFM Framework for advancing the forest bioeconomy? Are the policy action areas suﬃciently comprehensive and eﬀective? What roles do you see for the CCFM in advancing the bioeconomy?

Breakout groups dialogue on draft CCFM Framework

New Technology Reseach within organosolv pulping, hot water extraction and pyrolysis Ethanol Xylosides Formation during Ethanol Organosolv Pulping

Kathleen McFadden At the end of the session, participants were invited to discuss the key elements of the framework. This facilitated session focused on answering the question, ‘what are the critical success factors for making Canada a recognized global leader in the forest bioeconomy?’ Organizers of the interactive workshop sought input from participants, and also encouraged online participation via a survey located on the CCFM website. Questions raised in the discussion include:

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Mehmet Sefik Tunc, from the University of Maine, presented research work on ethanol xylosides formation during ethanol organosolv pulping. The objective of the study was to quantify ethyl-xyloside formation during acid-reinforced ethanol pulping of hardwood. The experiments were conducted in a multi digester with mini reactors, and followed by separation and washing stages to separate the spent liquor and the pulp. Depending of the different cooking parameters the pulp yield was heavily influenced. The main conclusions of the work were: Formation of the xylosides are explained by acid catalyze reaction between ethanol and xylose.

Formation increases for regular Alcell process with increased severity but up to 1% on od wood. For sulfuric acid catalyzed Alcell process, formation of the xylosides was more pronounced and it increased alongside heightened severity, of up to approximately 8% on wood. Pulp yield decreased with increased severity.

Mehmet Sefik Tunc Hot water extraction for producing lignocellulosic derived sugars key performance indicators Jawad Jeaidi, NRCan – CanmetENERGY presented work conducted on hot water extraction for producing lignocellulosic derived sugars and its key performance indicators. The Liquid Hot Water Extraction, LHWE, process uses only hot water and pressure. A case study was conducted for the purposes of analyzing the technical impacts, economic performance and environmental footprint of the LHWE process for the pretreatment and fractionation of woody biomass. The benchmarking options were a standalone LHWE biorefinery, versus an integrated LHWE biorefinery within a TMP mill. The results indicate that LHWE can offer a potential solution to revamping TMP mills, particularly those with extra biomass and/or idle refiner lines.

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Integrated LHWE-TMP versus standalone LHWE results indicate: Improved environmental footprints: 50 % reduction in global warming and resource consumption impacts Lower CAPEX: 75% reduction in total capital investment Energy savings: lower electricity demand at TMP reﬁners, and production cost savings of up to 20% Improved economics due to lower CAPEX and OPEX Lower the market entry risk

oils, water) but reduces the yield of organics (high, low viscosity oils) by 10 %. In addition, it is mobile and compact, cheaper to build and operate, and is appropriate for new applications.

In this presentation, researchers sought to answer the question of how lignin can be produced in an integrated forest bioreﬁnery. The particular case that was analysed involved:

Clement Villemont

Designing kraft lignin based dispersant for clay suspension

Jawad Jeaidi Mechanically fluidized pyrolysis pilot unit as a densification medium and new applications for forest biorefinery; exploratory results by Clement Villemont, UQTR. Bio-oil is an interesting raw material for a number of applications like bitumen, adhesives, pesticides, fertilizers and pharmaceuticals. One method of densifying the raw material is by pyrolysis, to make distribution more cost efficient, i.e. distribute bio-oil instead of wood residuals of different kinds. UQTR has developed a pyrolysis demonstration plant called MFR, with the capability of using two tonnes of raw material per day. The MFR method provides a fractionated bio-oil with higher viscosity and heating value, lower water and acidic acid content, and has a higher stability compared to conventional pyrolysis methods. In comparison with conventional bubbling fluidized bed, MFR provides uncontaminated biochar, yields more liquid (high, low viscosity

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Economics and environmental profiles of Kraft-lignin derivatives: Carbon fibre and flexible polyurethane foam industrial case studies

Kohan Kandori, of Lakehead University presented ﬁndings of a research project on how to design kraft lignin-based dispersant for clay suspension. Because each type of dispersant comes with particular disadvantages, there is a drive for biodegradable options, one of which could be lignin-based.

Kohan Kandori In this particular project, lignin was selected as a potential agent. As such, it was necessary to first discover the lignin and kaolin suspension properties, and to determine how the two interact. The first step was to oxidize the lignin to make it water-soluble. Different oxidized lignin were analysed to determine how well it acts as a dispersant. These dispersion tests were conducted in a DDJ unit, in order to evaluate the lignin’s ability to disperse kaolin.

Integrated forest biorefinery being it a kraft pulping mill with lignin recovery; A representative Canadian softwood kraft mill producing 1000 odt/d of pulp; Two lignin derivatives: flexible polyurethane foam (PU) & carbon fibres. The conclusions for the case study involved; Partnership between the forest industry and lignin uptakers lead to economically and environmentally viable opportunities; Lignin valorisation is promising for revenue diversification & forest industry transformation; The forest industry can consistently produce large volumes of lignin to meet the demands of the automotive industry; Technological, market and financial risks must be addressed; The technical risks associated with lignin extraction are significantly lower than lignin upgrading; A phased implementation strategy can be used to mitigate the risks; The demonstrated multi-criteria analysis approach can be used to evaluate other lignin derivatives with automotive applications; Government support in the form of subsidies and incentives greatly enhances the profitability of ligninbased polyurethane and carbon fibre manufacturing.

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Canada’s forest-based energy: status and trends

Olumoye Ajao

Characterization of lignin from different sources: Variability of lignin colour and its impacts on quality control of bio-based production processes The research sought to answer a number of questions. How can we address lignin’s colour to make it suitable for other products as a replacement for non-renewable raw materials? How can it be modified in order to eliminate differences from individual mills? Lignin from two kraft mills located 200 km apart was used. The objectives of the study were to determine what causes colour variations in lignin, and how they can be managed. The use of lignin as a substitute requires matching product specifications. The initial colour of lignin influences the colour of its derivatives. For some applications, lignin colour is a critical specification, just as it is for bioplastics, cosmetics, anti-oxidants, etc. Variation in the colour of lignin was shown to be process and feedstock-dependent. Results of the study indicate that colour specification was met for ligninbased carbon black. Optical properties can support the bio-based product development, process optimization and process quality control. In the future, colour-based process control strategies could be explored. It was also discovered that colour could provide insight into material characteristics if correlated to molecular structure.

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The BIOFOR session focused on advancements in biorefining technologies, lessons learned, key performance indicators and general technical and economic trends impacting the development of this futuristic and sustainable energy stream. In her welcome to participants moderator Mariya Marinova of Université Laval, underlined the importance of the biorefinery as part of the industry’s strategy to generate new revenues and restore its profitability.

Mariya Marinova Jawad Jeaidi, NRCan – CanmetENERGY, gave a presentation on biomass-based power generation systems in Canada. He provided a description of its status, key performance indicators, implementation challenges and discussed lessons learned by his team at CanmetENERGY (Olumoye Ajao, Marzouk Benali, Mouloud Amazouz and Serge Bédard). Some of the objectives of their work included the review of power generation systems in Canada and the identiﬁcation of trends for power generation systems suitable for the forest industry. Recalling that renewable power is one of Canada’s strategies to decrease its greenhouse gas emissions, he noted some of the beneﬁts of integrating power generation systems into typical Canadian Kraft pulp and newsprint mills. He also stressed that biomass-based power generation systems hold a valuable competitive advantage over other renewable power generating systems.

Jawad Jeaidi The presentation, entitled ‘Bioenergy in Canadian Forest Industry: Performance metrics, lessons learned and key technology gaps,’ was provided by Marzouk Benali, NRCan – CanmetENERGY. Benali provided an overview of bioenergy’s global position, and an analysis of Canadian bioenergy demonstration projects. Benali noted the federal government funded a total of 1,795 projects between 2009 and 2015, and that 220 out of these were linked to bioenergy and on this total. An additional 86 were found to have direct relevance to the forest industry. Bioenergy being the largest renewable energy source in the country, one can understand why Ottawa invested approximately $800 million in demonstration projects across the country to catalyze the development of the Canadian bioenergy sector, by increasing its bioenergy production capacity. This is good news for industry, Benali noted, since an eﬀective mix of public and private ﬁnancing is typically helpful in lowering risk. In this context, he noted, federal grants help moderate the requirement for capital investment, and provide the project with credibility that attracts private investment.

Marzouk Benali

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Stephanie Jean of Polytechnique Montreal, presented her research work on the economic and environmental assessment of integrated fast pyrolysis processes with a specific focus on the case study of biorefinery projects in Happy Valley Goose Bay. The Government of Newfoundland and Labrador is exploring potential uses of the forest resource through biorefinery projects and there are already many lessons that can be drawn from the experience. Takeaway messages included the fact that the best environmental option is not always obvious, and that it depends on the endpoint impact category considered.

railroads and harbours positions it well for a project of this sort. While 40% of the biomass will come from areas less than 50 KM away, if longer distances are required, energy densiﬁcation will be necessary, as biomass must be supplied at low costs to ensure viability of the project, and chips and saw dust are too costly of raw materials. Reducing biomass supply costs is a main challenge, and it will be necessary to ensure long-term contracts (a 25 –year time frame would be favourable) are in place. Diesel cost is also a critical factor for transportation. It will be important that the bioreﬁnery support, and not compete with, other parts of the forest industry and not create market distortions by driving up costs for other industry players. Another issue of importance is deciding on the size of a demo plant. Wood-based fuels have a higher energy content and less CO2 than e.g. bioethanol from wheat.

Stephanie Jean

Process Advancements BIOREFINERY Advancement in the biorefinery field The La Tuque Project (BELT) The La Tuque project is an ambitious undertaking and of great interest to both the Quebec and federal governments. Plans for the full-scale bioreﬁnery involve 1.2 MT/year of forest residues that will be converted into 233.3 MW of renewable diesel for drop-on applications. The project is supported by extensive studies that have been concluded widespread support for a bioreﬁnery based on forest residues. Because transportation is a critical concern in a project of this nature, La Tuque’s favourable location with easy access to roads,

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Patrice Mangin Conclusions Pre-feasibility studies are encouraging; Process lines studied are proposed to outline the challenges; Technology solution not necessarily equivalent to lower techno-economic risk solution; No technology can provide the answer if studied separately. Constant need to go back and think, re-think and re-think the whole process line.

The Biorefinery Pulp Mill Peter Axegård, RISE Bioeconomy, shared his perspectives on a biorefinery kraft pulp mill. He stressed that global trends are increasing demand for sustainable pulp fibres, and that most sectors are responding and doing reasonably well in this regard. Axegård suggested it is possible add new businesses alongside existing big kraft mills, with the introduction of new products such as cellulose for textiles, lignin as raw material for new products, fuels, chemicals, biogas, food and soil improvement. In the future, it is possible that cellulose composites and textile filaments may be produced in an actual mill environment. Fibrillar cellulose offers a range of new applications in paper and packaging, new materials and many others. Lignin is a new product from a kraft mill. Carbonised lignin-based carbon fibres is an area of huge interest to the automotive industry, due to the possibilities to add functions, reduce weight and costs. The discussion ended with a summary of major conclusions: Pulp mills are well positioned to be nodes for new value chains; Countries with large forest assets and pulp mills will benefit; Several biorefining processes are under development; Momentum for a forest based economy; Value added products;

Peter Axegård

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The panel discussion opened up a dialogue about the various questions that remain unanswered, such as, should there be a one product reﬁnery or a pulp mill adding a number of value-added applications? Which are the pros and cons of each approach? What is the importance of optimizing transportation costs of raw material? Which product will be commercialised ﬁrst? Which governmental incentives are needed? When will technologies mature and become mainstream?

ment of cellulose filament technology, based on FPInnovations IP is an example of a company that is doing this well. Kruger serves as another example that has successfully broken into the biomaterials market. It opened the world’s first cellulose filaments plant in 2014, with a capacity of 6,000 tonnes per year. The company uses most of its own product within its other business lines. Fibria currently makes eucalyptus pulp and electricity, but the company is also gearing up to produce an increased amount of bioproducts and biofuels in the future. Some of the notable conclusions generated by the panel discussion included:

Revamping pulp and paper mills A panel discussion featuring Nicolas Duplessis, Mike Rushton and Gurminder Minhas and chaired by Paul Stuart sparked a dialogue on a range of issues on revamping pulp and paper mills. While newsprint has declined for 15 consecutive years and led to a corresponding removal of 8.6M tonnes per year of newsprint from the market, things are now stabilizing. At this juncture, however, it is critical to harness innovation to break into new markets based on bio-based chemicals, fuels and materials. BioFilaments, a company focused on commercial deploy-

In order to be successful it is important to choose the right technology and partners and to be aware of where the present product markets are going early enough to take necessary measures. In recent years, forest companies have invested in new opportunities, either by acquiring innovative companies with key technology competencies, and/or building up their internal competence. Cooperation with research institutes and universities is on the rise, and as a result, more and more innovative work is being done outside of traditional business settings. The importance of seeking outside expertise instead of generating

Mike Rushton, Nicolas Duplessis, Gurminder Minhas and Paul Stuart

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it internally to gain efficiencies, was stressed. The justification for maintaining an in-house R&D capacity, if one can afford to do so, however, is based on ownership of the intellectual property, particularly if you decide to patent your outputs. Competition is healthy as it forces companies to continue developing. While some companies will inevitably fall, those that remain standing will be stronger. New bioeconomy developments mean that companies are entering new markets. A large volume of potential seekers of the market mean the challenge is then to distil down to the best options and not pursue everything, needlessly. How can the forest sector attract required new capital to support new projects?

3D Printing Workshop 3D Printing opens a lot of opportunities The topic of 3D printing made its debut at PaperWeek 2017, with a number of experts from North America and Scandinavia present to discuss developments in the industry. The large number of workshop participants confirmed 3D printing’s status as a hot topic. Machining, a subtractive technology, involves the removal of material to form desired objects. 3D printing, by contrast, is an additive technology, which involves the addition of material to build up a product. It uses a digital file containing information about all of the layers required, and a feed stock. There are four different technologies required for 3D printing like e.g. spraying and extrusion.

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can be done, noting that intelligent materials can collaborate with robots to result in a smarter, combined product.

The Wood Region, arena and testbed for biocomposites and 3D printing technologies Skylar Tibbits Today, a number of materials can be 3D printed. Biocellulose, together with plastic forms a kind of material which can then be used as feedstock for packaging and absorbent products. There are a number of possibilities for lignocellulosic materials such as wood flour containing filaments and cellulose-based bio ink. Companies around the globe are investing in 3D printing. GE has introduced a 3D printed part for an aircraft engine, and Valmet 3D now prints refiner plants. Wood containing filament is a small market, but it offers huge potential in the area of customised packaging. To support development in this arena, it will be important to find suitable applications for development projects. When you have 3D printed pieces of any shape you are faced with an assembly problem. Self-assembly is a process by which different parts are automatically put together, requiring specialized software. We are still in the very early stages of selfassembly, but significant strides in development are being made. 4D printing is the addition of time as a fourth factor. In practical application this means that a material is programmed to allow for changes to occur over time. Such changes can be caused by a number of factors such as moisture, temperature and pressure. Skylar Tibbits from MIT presented a number of examples how this

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Thomas Bajer gave a presentation on The Wood Region (TWR). Noting the surplus of sawdust and PET (polyethylene plastic) in Sweden, using it as raw material for new products is of great interest. The Wood Region, now with EU financing for the next five years, offers a development centre for wood products and bio composite materials with an emphasis on design, material and prototyping. TWR uses sawmill dust as raw material for its development projects. By grinding it, the dust can then be used in a variety of products such as paint, or, with the addition of other materials such as bioplastics, it can be used in 3D printing extruding technology. TWR has an ABB robot for bigger applications, such as the 3D printing of canoes, foot supports, panels and horse shoes. Fibreboards, whose patent is pending, is yet another product area for TWR that uses sawdust as raw material.

Thomas Bajer

TreeD printing

Mikael Lindström, RISE Innventia, presented some of Innventia’s current projects, and those it is undertaking with partners. The company, in recognition that additive production will be an important segment of

the industry going forward, notes that depending on the application, 25-40% of the 3D printed ﬁlaments can be cellulosic material, while the remainder must be composed of plastic.

Mikael Lindström Tree D project aims to print as much wood content as possible. The feedstock is yarn, which in the process is impregnated with PLA and the extruded. While experiments have been successfully conducted using up to 80% fibre content, the challenge will be to print up to a width of one inch. In this process, nanocellulose is used, but mixed with different materials, such as sawdust. It is critical to ensure that material development is done in close collaboration with process and equipment development to ensure compatibility. Multi component printing pastes for 3D printing bio-based hydrogels Panu Lahtinen, VTT, Finland, discussed the work his company is doing to develop printing pastes for 3D printing applications. One application of note was a tree with solar cells in its leaves; everything had been 3D printed. VTT has producted filament and yarn, which excludes the dissolving process when producing filament and yarn for textile use. Smart wound dressings, which use bio-based material and have electronics embedded is another example of work currently in the pilot stage. In the future, it is hoped that 3D printing with living cells will make it possible to print things such as human ears!

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The process to produce a printing paste involves the mixing of alginate and plasticizer with a ﬂuid. Then, nanocellulose is mixed, ﬁller is loaded and also mixed, and then you are ready to print. After the printing process is complete, a post-treatment is required to ensure the objects being printed have the correct properties.

Biomaterial polymer blends for 3D printing Lokendra Pal, of NC State University, and the last speaker of the session, noted that computing power is a prerequisite for 3D printing. Honda was the first to reveal the 3D printed car, consisting of 3D printed parts. In Dubai, the first 3D printed house has already been seen. Today, plastics are the most common material used in 3D printing, and this will be offer an opportunity for the forest industry to partly replace plastic with cellulosic material.

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WHY JOIN PAPTAC? Access to a wide and well-established network, including an on-line directory for members; Participation privilege on PAPTAC's technical communities through meetings, e-mail discussion groups, conference calls, on-line forums and blogs; Privileged member access to J-FOR on-line; A one-year subscription to Pulp and Paper Canada magazine, and the PaperAdvance and Le Maître papetier e-newsletters; A free complete set of Engineering Data Sheets and Standard Testing Methods; Reduced rates on books, events, courses and more.

Lokendra Pal The research at NC State University is focused on developing polymer blends and processing techniques for 3D printing by using cellulose and lignin as well as LSA. The work is done as powder printing and ﬁlament printing. When using powder, the object must cured to get the ﬁnal properties.

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PAPTAC is a wide and well-organized network of individuals and represents a world of information exchange and experience for the benefit of the professional development of its members and the pulp and paper industry. We are inviting members to get actively involved in our industry by joining our technical communities, by attending conferences and presenting papers, and by participating in our TECH courses and Webinars. The benefits of involvement and participation will provide value back the individual member, the company and to the industry.

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FPINNOVATIONS – A LEADER IN ENHANCING PRODUCT PERFORMANCE At FPInnovations, we are building a world-class tissue innovation program around our unique pilot tissue machine and high-quality Canadian fibres to support the industry’s move towards growing market segments.

OUR NAME IS INNOVATION fpinnovations.ca FPInnovations is a not-for-profit world-leading R&D organization that specializes in the creation of scientific solutions in support of the Canadian forest sector’s global competitiveness and responds to the priority needs of its industry members and government partners. It is ideally positioned to perform research, innovate, and deliver state-of-the-art solutions for every area of the sector’s value chain, from forest operations to consumer and industrial products. FPInnovations’ staff numbers more than 525. Its R&D laboratories are located in Québec, Montréal, and Vancouver, and it has technology transfer offices across Canada. For more information about FPInnovations, visit: www.fpinnovations.ca.

2017 PAPERWEEK CANADA

BUSINESS LUNCHEONS

The PaperWeek Luncheons are one of the most popular draws of the event.

Carr: Forest industry shaping the curve ahead

The Honourable James Carr, Minister of Natural Resources, Canada gave a forward-looking keynote address to a packed venue full of eager listeners. Building on the PaperWeek 2017 theme, ‘Staying Ahead of the Curve,’ Minister Carr believes, “the industry is not just looking ahead of the curve, it is shaping it.”

sector in particular has become one of the most innovative sectors in the Canadian economy.”

To ensure that Canada meets its commitments and supports the forest products industry, the Canadian government supports research, innovation and the development of new products. To Minister Carr shared his views on Canada underline this point, Minister Carr stressed and its position as a leader in the forestry that the Government of Canada is investing sector on an international stage, cautioning $9 million in a Fortress Specialty Cellulose that, “we will not be able to maintain our Hemicellulose Project in Thurso. The expeleadership role without some effort since rience of Papier Masson, who received industry transformation is still underway.” $12.5 million to establish a new process to The Minister’s presentation underlined produce wood fibres for the production of four main challenges Canada’s sector is wood-plastic composites, the first project facing, those of climate change, the race of its kind in North America, was also highto develop innovative products and techlighted. AE Bioenegry Côte-Nord received “The industry is not just nologies, economic opportunities for close to $44 million to produce biofuels. looking ahead of the curve, indigenous peoples and for rural areas The Port-Cartier plant will be the first it is shaping it.” and the development of new markets. commercial-scale facility of this kind. When the project is completed, it will convert Minister Carr underlined the rapidly changing face of the industry, forest residue into 40 million litres of renewable fuel every year. noting that today’s forestry worker does not wear a red and When upgraded into transportation fuels, this will remove up black plaid shirt, but a white lab coat. "Not long ago, the forest to 70,000 tons of CO2-equivalent emissions on a yearly basis. industry’s reputation seemed outdated. But something remarkIn 2016, the government committed $1 billion for a period of able has happened. The forest industry and the pulp and paper

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four years to develop clean technologies. It is expected that a large chunk of this funding will be channeled to technologies that directly support the forest industry. Minister Carr closed his talk by noting that forestry has written several chapters of Canada’s history but that the story will unfold for many years to come. “We still have uncharted territories to explore, and it will be by working together – government agencies at all levels, companies and researchers – that we can take up the (bioeconomy) challenge.” Minister Carr suggested this collaboration will form the base of our collective drive towards a spirit of discovery. “I think the best chapters of the industry’s history are not yet written,” he said.

Air Canada is an opportunity for the forest industry

Mena Salib, Manager of Aircraft Noice and Emissions at Air Canada, gave an interesting keynote luncheon speech in which he challenged the forest industry to come up with biojet fuels in large quantities, at the right price level.

Through IATA, the international airline association, Air Canada has committed to reducing the environmental impact of its airline traffic. The company has outlined its own targets and laid out how it plans to achieve these goals. The journey won’t be an easy one. First, the annual 4% increase in air travel will, in 20 years’ time, represent a doubling of the amount of air travel passengers, making the goal of reducing CO2 emissions all the more challenging. In response, Air Canada is tackling the problem in a number of ways. One of the approaches is its investment program, whereby the company is pumping money into 159 new and more energyefficient aircraft, in order to reduce the consumptions of fuel and resulting emissions. To test out how to use fuels that contain a bio-based part, Air Canada optimized an Airbus aircraft for a flight from Toronto to Mexico City, to minimize its fuel consumption. Astonishingly, the flight emitted 40% less CO2. Air Canada would also like to use domestically produced sustainable fuel. Given the quantity it would require, the biofuel can only

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be based on forest raw material. In the long-term, the company is looking to the forest industry for a stable supply of fuel, and Salib outlined a number of crucial factors that potential suppliers will have to address. Notably, the goal will be to reduce the amount of traditional fuel, according to ASTM, and instead rely on a mix of bio-based fuel. The source must be sustainable, and the raw material must come from sustainablymanaged forests. Also important is price: given that 20% of a ticket sale for an airplane seat is driven by fuel cost, expecting consumers to accept a price hike for travel fuelled by bio-based products, is not realistic. The supply must be consistently available, which will require deep commitments from suppliers. Given that just 1% of Air Canada’s fuel consumption in 2014 was a whopping 42 million litres, this is a tall order. Potential suppliers will also be required to offer proximity to a travel hub, as the company is mindful of diminishing a positive environmental effect by having to transport the biojet fuel itself a long distance to the airport. “Locally grown” supply will be a bonus. Salib’s final words to her audience were those of caution: It is very important not to rush, better to be safe than sorry. Get it right, or you will not get it at all.

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PAPTAC NATIONAL AWARDS

PAPTAC Executive Director Greg Hay welcomed participants to the awards luncheon by underlining the importance of the

Association’s national awards for business and research leadership, as well as for service to the Canadian pulp and paper industry. “Awards are presented each year to the best of the best, people we can find inspiration from, people who lead the way on the road to the sustained future of the forest industry,” Hay noted. The PAPTAC National Business Awards recognize mill leadership excellence in the fields of Safety Leadership and Environmental Strategy. The Association commended the quality of the submissions it received, which were judged by a rigorous panel of industry experts. Safety Leadership Award Tom Paisley, Mill Manager, Irving Paper, presented the day’s first award - the Safety Leadership Award. This year’s winner was Resolute Forest Products Kenogami Mill. Robert Dufresne, Vice-president, Resolute Forest Products accepted the honor on behalf of the facility, and he expressed heartfelt thanks to the Kenogami Mill team. PAPTAC’s representatives made particular mention of the mill’s exceptionally low incident rate.

Tom Paisley & Robert Dufresne

Environmental Strategy Award Robert Dufresne then presented the 2017 Environmental Strategy Award to Domtar’s Windsor Mill for its overall achievements in the areas of greenhouse gas reduction, use of forest waste, water treatment, etc. Eric Ashby, Vice President & Mill Manager, Domtar Windsor received the award and highlighted the extensive work the mill has undertaken in the domain of environmental management since he started working in the sector about 30 years ago. He referred to the progress as nothing short of astonishing and noted this should “give us hope for solutions to today’s sustainability challenges. We should all be very proud for our families and especially for our children”. 40

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Robert Dufresne & Eric Ashby

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PAPTAC NATIONAL AWARDS

New Chairman: PAPTAC’s Executive Council The luncheon also provided occasion to announce that Eric Ashby will assume the role of Chairman of PAPTAC’s Executive Council. Robert Dufresne, who will be leaving the post, was commended for his relentless engagement and support of the Association and received a commemorative plaque in thanks.

Eric Ashby & Robert Dufresne

Honorary Life Membership After the keynote luncheon presentation by The Honourable James Carr, Minister of Natural Resources, PAPTAC’s Chairman Robert Dufresne (Vice-president, Resolute Forest Products), presented PAPTAC’s Honorary Life Membership to Daniel Archambault, Executive VP and COO of Kruger and previous chairman of PAPTAC. Daniel Archambault received an honorary plaque by the Minister of Natural Resources, the Chairman of PAPTAC and by Greg Hay, Executive Director of PAPTAC. Archambault, who has 40 years’ experience in the pulp and paper sector, thanked all of the PAPTAC Executive Council, PAPTAC fellows, his industry colleagues, and paid special tribute to the role of Joseph Kruger, owner of Kruger, who, Archambault noted, always supported his commitment to the Association and its work. Eric Ashby presented an Honorary Life Membership to Tom Johnstone, Management/ Leadership Consultant, T.D. Johnstone & Associates. Mr. Johnstone is Senior Consultant at Buckman, a 50-year member of the Association, and has been a PAPTAC Executive Councilor since 2011. Honorary Life Memberships are conferred upon individuals who demonstrate extraordinary dedication to the Association. In accepting his membership, Johnstone confessed with a smile that he was reluctant to join the industry altogether when he started up a consolidated mill in Quebec in 1967, noting the lure of a summer job close to Expo 67 was the true motivation. At the time, for a chemical engineer, the ‘sexy industry’ was found in petrochemicals, though, this has certainly changed since the 1960s, Johnstone noted. Fortunately, the intellectual stimulation and challenges prompted Johnstone to commit himself to pulp and paper, and he proudly conﬁrmed that he never regretted his choice.

Daniel Archambault, Robert Dufresne, Minister James Carr, and Greg Hay

Eric Ashby & Tom Johnstone

John S. Bates Memorial Gold Medal Eric Ashby, presented the John S. Bates Memorial Gold Medal to Patrice Mangin, UQTR/CRML and CEO of BioÉnergie La Tuque. The John S. Bates Memorial Gold Medal is PAPTAC's highest individual honor conferred by the Association and is awarded to a member in recognition of his or her invaluable contribution to the science and technology of the pulp and paper industry. In his remarks upon accepting the award, Mangin suggested it is a thrilling time to work in the industry, perhaps one of the most interesting sectors to work for in the 21st century and that he wishes he could be young enough to do it all over again. “Working for an industry where science and technology takes such a central place and which is based on renewable materials is just fantastic,” he said. Thanking the forest industry and pulp and paper community, he dedicated his medal to his wife and daughter.

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Eric Ashby & Patrice Mangin

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PACTAC Fellowship Awards This year’s PACTAC Fellowship Awards were bestowed upon Martin Fairbank, Consultant, Roger Gaudreault, VP R&D Innovation TGWT Clean technologies Inc., Sylvain Robert, Professor at Université du Québec à Trois-Rivières and James Olson, Professor at University of British Columbia who was unable to attend because of the weather conditions in Western Canada.

Sylvain Robert, Roger Gaudreault, Martin Fairbank, and Greg Hay

Howard Rapson Memorial Award The Howard Rapson Memorial Award for best chemical pulp bleaching paper was presented to Mona Henderson of Valmet for her paper entitled, "Impact on Fiberline when Adding New Brown Stock Washers", co-authored by Anders Hjort, Valmet. The presentation highlighted their work on where in the ﬁberline pulp washing equipment should be placed, and which type, in order to achieve optimum results. Mona Henderson and Greg Hay Member Leadership Award The Member Leadership Award was presented to Mike Soucy of Kadant for his continued leadership and involvement in the PMTC, PAPTAC Papermaking Technology Community. Louis Morimanno, of Omya, presented the award to Soucy and noted his longstanding work on the Annual Meetings and commended his 20-year tenure as chairman of the PMTC.

Mike Soucy and Louis Morimanno

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Journal of Science & Technology for Forest Products and Processes: VOL. 6, NO. 2

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RHEOLOGY OF DISPERSIONS OF SPHERES AND CELLULOSE NANOFIBRILS ABSTRACT

LEILA JOWKARDERIS, THEO G.M. VAN DE VEN* The rheology of suspensions of cellulose nanofibrils (CNF) mixed with spherical silica particles is studied. The sphere diameter is on the order of the nanofibril length. The results show a decrease in the elasticity and stiffness of CNF suspensions with silica addition. However, the viscosity and the degree of shear thinning of the samples are not significantly affected by silica particles. The results are of potential interest in papermaking, where both silica and cellulose fibrils are added to a papermaking dispersion, and suggest that adding them together as a single suspension might be beneficial.

INTRODUCTION

Cellulose nanofibrils (CNF) produced by disintegration of wood fibres are high-aspect-ratio and rigid rod-like particles, each consisting of a number of linear cellulose chains. CNF are renewable and biodegradable and can be chemically modified for specific applications. The viscous suspensions and stiff gels that these nanofibrils form in water have been recommended for modifying the rheology of food, paint, cosmetics, and pharmaceutical products [1â&#x20AC;&#x201C;4]. Silica particles are widely used in papermaking either as a retention aid [5] or as pigments in paper coating. Recently, cellulose nanofibrils have also been used in papermaking to increase paper strength [6]. This research has studied the rheology of cellulose nanofibril suspensions mixed with spherical silica particles at various silica/CNF ratios. The diameter of the spherical particles was chosen to be comparable to the length of the rod-like nanofibrils, which is about two orders of magnitude larger than their width. The rheology of CNF suspensions with various additives such as salt, acid, and polyelectrolyte has been studied in the literature over a wide concentration range

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[7â&#x20AC;&#x201C;13]. Large elastic modulus, solid-like structure, and shear-thinning behavior are characteristics of these gels. However, it has not been studied how the rheology of these suspensions is affected by addition of colloidal spheres. In general, the rheology of mixtures of spherical and rod-like particles has not been investigated. Addition of spherical particles significantly increases the polydispersity in particle dimensions, and therefore variation in the rheological properties of the dispersions is expected, similarly to polydispersed suspensions of spherical particles [14].

from Sigma-Aldrich in the form of nanopowder. An average diameter of ~400 nm was measured for the spheres by DLS.

EXPERIMENTAL Materials

TEMPO-mediated oxidized CNF prepared using NaClO was received from the Forest Product Laboratory (FPL) (Madison, WI) as a 0.9% w/w aqueous suspension. The charge density of the sample, as reported by the manufacturer, was 1.2 mmol g-1 dry CNF in the form of COONa. An average length of ~600 nm and an average width of ~4 nm were estimated for the nanofibrils [15]. Silica nanoparticles were purchased

Journal of Science & Technology for Forest Products and Processes: VOL. 6, NO. 2

THEO G.M. VAN DE VEN

Pulp & Paper Research Center and Department of Chemistry, McGill University, Montreal, Qc Canada *Contact: theo.vandeven@mcgill.ca

LEILA JOWKARDERIS

Department of Chemical Engineering, McGill University, Montreal, Qc Canada

TRADITIONAL AREA CONTRIBUTIONS

The ζ potential of silica suspensions was reported as ~−45 mV at neutral pH [16]. CNF suspensions with solid mass fractions of 0.3%, 0.4%, and 0.5% w/w were prepared by adding deionized water. A standard silica dispersion with 20% w/w mass fraction was prepared. The silica dispersion was added to the CNF suspensions using a pipet to bring the silica/ CNF ratios into the range of 0.5–10. No silica sedimentation was observed in the sphere and rod mixtures. All samples were prepared at neutral pH.

causing a decrease in sample stiffness. Larger amounts of spherical nanoparticles (silica/CNF > 6), on the other hand, increase the elastic and viscous moduli because they increase the sample solids content. At 0.3% CNF, silica particles convert the sample from solid-like (G′ > G″) to liquid-like (G′ < G″). The sample shows liquid-like behaviour even at silica/CNF ratios up to 10, with a G′ value less than half that of the initial CNF suspension. At 0.4% CNF content, adding silica increases the elastic and viscous moduli

even at low silica/CNF ratios. Only at silica/CNF ≈ 1, where maximum polydispersity occurs, G′ and G″ are smaller than the values of the initial CNF sample, and G′ < G″. The reason for this unexpected behaviour is not clear. To make it easier to follow these trends, G″ / G′ values are shown in Fig. 2. Samples with G″/ G′ > 1 are liquid-like, and G″ / G′ < 1 is characteristic of a solid-like structure. Shear viscosities of all the samples containing CNF were measured at shear

Methods

Rheology tests were carried out using an MCR301 (Anton Paar) rheometer. Parallel plate geometry, with a 25 mm diameter (top plate) and a 1 mm gap, was used for the samples with 0.4% and 0.5% w/w CNF. Silicon oil was used around the geometry to prevent water evaporation. Suspensions with 0.3% CNF were tested using double-wall concentric cylinders, and evaporation was prevented by solvent traps. The samples were allowed to relax for 2 min in the rheometer before starting the test. Strain sweep tests were carried out in the range of 0.5%–200% oscillation amplitude at a frequency of ω = 1 rad s-1. Shear viscosity was measured at shear rates in the range of 0.5–10 s-1. The temperature was set to 25°C. RESULTS AND DISCUSSION

The elastic G′ and viscous G″ moduli remained constant with oscillation amplitude (strain) in the range ~2%–10% for all samples, indicating that all experiments were performed in the linear viscoelastic (LVE) regime. The linear values of G′ and G″ at different silica/CNF ratios are shown in Fig. 1 for the three CNF mass fractions. At 0.3% and 0.5% CNF contents, adding silica decreased the elastic and viscous moduli, even though the total solids content increased. The reason for this could have been an increase in sample polydispersity. In addition, the spherical silica particles might have acted as a lubricant among the cellulose nanofibrils,

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Fig. 1 - G′ and G″ of mixed suspensions at various silica/CNF ratios at strain ≈ 5%. The data point at silica/CNF = 0 represents pure CNF hydrogel. Error bars show the standard deviation from the average of two measurements.

Fig. 2 - G″ / G′ of mixed suspensions at various silica/CNF ratios at strain ≈ 5%. The data point at silica/CNF = 0 represents pure CNF hydrogel.

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Fig. 3 - Shear viscosity η as a function of shear rate at various silica/CNF ratios for the three CNF samples. Numbers in the graph indicate silica/CNF ratios.

rates in the range 0.5–10 s-1. At higher shear rates, the no-slip condition was not preserved. The viscosity of the silica suspensions without CNF was not measurable by the rheometer used because the viscosities were below the detection limit. As shown in Fig. 3, the sample viscosity decreased with increasing shear rate, indicating shear-thinning behaviour. The degree of shear thinning, here defined as the slope of the viscosity vs. shear rate curve, is not significantly affected by the silica/ CNF ratio because all the viscosity curves are almost parallel. The reason could be that in suspensions of spherical particles, for the concentrations used, the viscosity is not significantly shear rate-dependent. Therefore, the shear-thinning behaviour of the sphere and nanofibril mixtures is mainly dominated by nanofibrils. As long as the CNF content of the sample does not change, the degree of shear thinning remains constant in the range of silica/ CNF ratios studied here. Figure 4 shows that increasing the silica content of the samples does not significantly change viscosity at silica/CNF ratios up to 6. However, at silica/CNF = 10, the viscosity is twice as high as that of the initial CNF samples due to a significant increase in the solids content of the suspensions. CONCLUDING REMARKS

Fig. 4 - Shear viscosity of mixed suspensions at various silica/CNF ratios at shear rate ≈ 1 s-1. The data point at silica/CNF = 0 represents pure CNF hydrogel.

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In a mixture of cellulose nanofibrils and spherical silica particles, the elastic and viscous moduli are lower than those of the CNF suspensions, even at a total solids content up to seven times greater than that of the initial CNF sample, with silica/ CNF=6. At 0.3% w/w CNF, adding silica converts the suspension from solid-like to liquid-like despite the increase in the total solids content of the sample. However, at higher CNF concentrations, the suspension remains solid-like after addition of silica spheres. The viscosity and the degree of shear thinning of the mixture are mainly controlled by the CNF content of the sample, independently of the number of silica particles added, in the concentration range studied in this work. Hence, it

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might be advantageous, when adding both spherical nanoparticles as fillers and cellulose nanofibrils to a papermaking suspension, to add them together, thus facilitating the flow of the filler/CNF suspension as it travels towards the paper machine in the papermaking process. ACKNOWLEDGEMENTS

NSERC Innovative Green Wood Fibre Products Network is acknowledged for financial support. We thank the USDA Forest Product Laboratory (Madison, WI, USA) for providing the CNF sample and Prof. Milan Maric (Chemical Engineering, McGill University) for providing access to his rheometer. REFERENCES 1.

Turbak, A.F., Snyder, F.W., and Sandberg, K.R., “Microfibrillated Cellulose, A New Cellulose Product: Properties, Uses, and Commercial Potential”, Journal of Applied Polymer Science, Applied Polymer Symposium, 37:815-827 (1983). Herrick, F.W., Casebier, R.L., Hamilton, J.K., and Sandberg, K.R., “Microfibrillated Cellulose: Morphology and Accessibility”, Journal of Applied Polymer Science, Applied Polymer Symposium, 37: 797-813 (1983). Jorfi, M. and Foster, J., “Recent Advances in Nanocellulose for Biomedical Applications”, Journal of Applied Polymer Science, 41719: 1-19 doi: 10.1002/

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APP.41719 (2015). Zhao, J., Lu, C., He, X., Zhang, X., Zhang, W., and Zhang, X., “Polyethylenimine-Grafted Cellulose Nanofibril Aerogels as Versatile Vehicles for Drug Delivery”, ACS, Applied Materials & In5. terfaces, 7:2607-2615 (2015). Koepenick, M., “Papermaking on a Nano Scale”, Pulp and Paper Canada, 110 (2009). 6. Ondaral, S., Hocaollu, G., and Ergün, M.E., “Cationic and Anionic Nanofibrillated Celluloses as Dry Strength Additives for Papermaking”, Cellulose Chemistry and Technology, 49:617-623 (2015). 7. Pääkkö, M., Ankerfors, M., Kosonen, H., Nykanen, A., Ahola, S., Sterberg, M.O., Ruokolainen, J., Laine, J., Larsson, P.T., Ikkala, O., and Lindström, T., “Enzymatic Hydrolysis Combined with Mechanical Shearing and High-Pressure Homogenization for Nanoscale Cellulose Fibrils and Strong Gels”, Biomacromolecules, 8:1934-1941 (2007). 8. Agoda-Tandjawa, G., Durand, S., Berot, S., Blassel, C., Gaillard, C., Garnier, C., and Doublier, J.L., “Rheological Characterization of Microfibrillated Cellulose Suspensions after Freezing”, Carbohydrate Polymers, 80:677-686 (2010). 9. Iotti, M., Gregersen, Ÿ.W., Moe, S., and Lenes, M., “Rheological Studies of Microfibrillar Cellulose Water Dispersions”, Journal of Polymers and the Environment, 19: 137-145, doi: 10.1007/ s10924-010-0248-2 (2011). 10. Dimic-Misic, K., Puisto, A., Gane, P., Nieminen, K., Alava, M., Paltakari, J., and 4.

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Maloney, T., “The Role of MFC/NFC Swelling in the Rheological Behavior and Dewatering of High-Consistency Furnishes”, Cellulose, 20: 2847-2861, doi: 10.1007/s10570-013-0076-3 (2013). Benhamou, K., Dufresne, A., Magnin, A., Mortha, G., and Kaddami, H., “Control of Size and Viscoelastic Properties of Nanofibrillated Cellulose from Palm Trees by Varying the TEMPO-Mediated Oxidation Time”, Carbohydrate Polymers, 99:74-83 (2014). Jowkarderis, L. and van de Ven, T., “Intrinsic Viscosity of Aqueous Suspensions of Cellulose Nanofibrils”, Cellulose, 21: 2511–2517, doi: 10.1007/ s10570-014-0292-5 (2014). Jowkarderis, L. and van de Ven, T., “Rheology of Semi-Dilute Suspensions of Carboxylated Cellulose Nanofibrils”, Carbohydrate Polymers, 123: 416-423 (2015a). Luckham, P.F. and Ukeje, M.A., “Effect of Particle Size Distribution on the Rheology of Dispersed Systems”, Journal of Colloid and Interface Science, 220: 347356 (1999). Jowkarderis, L. and van de Ven, T., “Mesh Size Analysis of Cellulose Nanofibril Hydrogels Using Solute Exclusion and PFG-NMR Spectroscopy”, Soft Matter, 11: 9201-9210 (2015b). Metin, C.O., Lake, L.W., Miranda, C.R., and Nguyen, Q.P., “Stability of Aqueous Silica Nanoparticle Dispersions”, Journal of Nanoparticle Research, 13: 839850, doi: 10.1007/s11051-010-0085-1 (2011).

Journal of Science & Technology for Forest Products and Processes: VOL. 6, NO. 2

SOME PROCESS ASPECTS ON ACID SULPHITE PULPING OF SOFTWOOD ABSTRACT

RAGHU DESHPANDE, ULF GERMGÅRD*, LARS SUNDVALL, HANS GRUNDBERG Acid sulphite pulping is currently used to produce both paper-grade and dissolving-grade pulps, but its benefits are best seen in dissolvinggrade pulp production. In this study, acid sulphite pulping of either 100% pine or 100% spruce was carried out to investigate the effects of cooking conditions on final pulp composition. Higher cooking temperature had an impact on delignification rate, but also on lignin condensation reactions. These reactions were found to have a strong negative influence on the yield of cellulose and hemicellulose compounds in final pulp samples. The influence of time, residual cooking acid content, and temperature on delignification rate and lignin condensation reactions was analyzed. It was found that lignin condensation reactions were very frequent if the cooking acid concentration was too low.

INTRODUCTION

Sulphite pulping is an old process invented in the mid-1800s, which has been extensively studied both in the laboratory and at mill scale. Among its pioneers are (naturally) Tilghman, who obtained the first patent in England in 1866; Ekman, who started up the first commercial sulphite digester in 1874 in Sweden; and Alexander Mitscherlich, whose work led to the start-up of the first German sulphite pulp mill during the 1880s [1]. In more modern times, sulphite pulping was studied and improved during the mid-1900s by Rydholm and Annergren [2,3] and in the later 1990s by Patt and Sixta [4,5]. Sulphite pulping can be done at acidic, neutral, or alkaline pH, but most mills are acidic, either at low pH, i.e., 1.5±0.5 (acid sulphite) or at higher pH, i.e., 4.5±0.5 (bisulphite). The benefits of acid sulphite pulping versus bisulphite pulping in dissolving-grade pulp production are the more selective acidic hydrolysis of the hemicelluloses, the ability to reach low kappa numbers after the digester, and the faster delignification rate, which is a most desirable reaction [6]. The other advantage of acid sulphite pulping is its possible application in a biorefinery process with high production of

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bioethanol from sulphite spent liquors [7,8]. Although sulphite pulping is an old process and many sulphite pulping experiments have therefore been carried out over the years, we believe that the process can be further developed, and we have therefore undertaken a fundamental laboratory study to investigate this process further. However, acidic sulphite cooking is not suitable for certain softwood types like pine, birch, and Douglas fir because of the resinous phenolic extractives that are present in these wood species and that can catalyze lignin condensation reactions in pulp fibers [1,9,10] (Fig. 1). Wood lignin consists partly of α-hydroxyl and α-ether bonds, which are

RAGHU DESHPANDE

Karlstad University, SE-65188 Karlstad, Sweden

easily cleaved in an acid sulphite cook, with formation of benzylium ions. These α-aryl ether bonds are the major lignin fragmentation reaction during acid sulphite pulping [9,19]. The benzylium ions formed during acid sulphite pulping can react with other phenyl propane units of lignin to form carbon-carbon bonds at the C1 and C6 positions on the aromatic lignin. These lignin condensation reactions retard delignification and result in poor delignification and dark pulp that is difficult to bleach. The chemical charge with respect to total and combined SO2 must be balanced with respect to lignin content to avoid lignin condensation reactions and hence a “black cook” [10]. Apart from low

ULF GERMGÅRD

LARS SUNDVALL Karlstad University, MoRe Research, SE-65188 SE-89122 Karlstad, Örnsköldsvik, Sweden Sweden *Contact: ulf.germgard@kau.se

Journal of Science & Technology for Forest Products and Processes: VOL. 6, NO. 2

HANS GRUNDBERG

Domsjö Fabriker, SE-89186 Örnsköldsvik, Sweden

TRADITIONAL AREA CONTRIBUTIONS

cooking chemical content (i.e., combined SO2), certain wood species contain phenolic extractives that favour condensation reactions over sulphonation reactions. One example is pinosylvin and its monomethyl ethers in pine wood [1,9]. The thiosulphate formed during sulphite pulping also reacts with lignin and results in lignin condensation reactions [9,16]. Finally, it is well known that lignin condensation reactions are especially frequent in pine heartwood, whereas pine sapwood exhibits much fewer such reactions. Hence, a sulphite cook is a demanding balance between lignin degradation reactions that are highly desirable and lignin condensations reactions that are not desirable. The main objective of this study was to investigate the difference in kinetics for spruce and pine wood at different acidic sulphite cooking conditions. The aim was to add new knowledge about the mechanisms of acid sulphite cooking. MATERIALS AND METHODS

Spruce (Picea abies) and pine (Pinus sylvestris) chips were collected from a Swedish pulp mill and screened in a standard chip classifier. The chip classifier had a series of trays (45 mm-diameter perforations, 8 mm-wide gaps, 13 mm-diameter perforations, 7 mm-diameter perforations, 3 mm-diameter perforations, and < 3 mmdiameter perforations); the chips retained on the 13 mm tray were used for the experimental trials. Knots and bark were manually removed. The acceptable chips were stored at -20°C until needed for the cooking experiments. The cooking experiments were of acid sulphite type and were performed in laboratory autoclaves with a laboratory-prepared cooking acid. The composition of the cooking acid is shown in Table 1. TABLE 1

Fig. 1 - Lignin in pulp can be degraded and then removed from the pulp to the surrounding liquor phase or else react internally in so-called lignin condensation reactions. Such reactions can, in the worst case, lead to a so-called black cook and a useless pulp.

The temperature profile during the initial phase of the cook was divided into two parts, with an initial impregnation time of 2 h to reach the final cooking temperature followed by cooking at that temperature. The start-up temperature was 100°C, and the liquor-to-wood (L/W) ratio was always 4.6. The cooking temperatures were 132°C, 142°C, and 154°C, as shown

Fig. 2 - Temperature profiles during laboratory cooking at three cooking temperatures.

Composition of laboratory cooking acid.

Laboratory-prepared cooking acid Total SO2, % 3.8 Combined SO2, % 0.6 Free SO2, % 3.2 Base as Na2O on wood, % 2.5 pH 1.5

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in Fig. 2. Note that the reported cooking time was defined as beginning when full cooking temperature was reached, meaning that the impregnation time was not included. The initial mass of chips in each 2.5-litre autoclave was 100 g, calculated as oven-dry matter, and these autoclaves were rotated slowly in a PEG (polyethyl-

TABLE 2

Test methods used for wood and pulp samples.

Acetone extract Klason lignin Lignin (UV) Arabinose, galactose, glucose, mannose, and xylose Total-S *Calculated as anhydrous sugar.

ISO 14453 TAPPI T-UM 250 TAPPI T 222 SCAN-CM 71:09 * SCAN-CM 57

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ene glycol)-filled laboratory digester. The cooking acid had a total SO2 content of 3.8%, a combined SO2 of 0.6%, and a free SO2 of 3.2%, calculated as SO2. The base (cation) charge was 2.5% measured as Na2O on wood. At the end of each cook, the autoclaves were cooled rapidly by submerging them into cold water at about 10°C to stop further reactions. Pulp and liquor samples were then collected. The pulp samples obtained were washed overnight with distilled water and then dried at 45°C in an oven to air-dried equilibrium conditions. After drying, the pulp samples were ground in a Wiley mill to produce a pulp powder that could pass a mesh of 0.4 mm (40 mesh). These powder samples were used for analysis of the various pulp components, as described in Table 2. The spent cooking liquors were analyzed as specified in Table 3. The pulp composition was calculated on acetone-extracted chips. The weights of carbohydrate monomers were recalculated to the initial carbohydrate polymers using the correlations proposed by Meier [11]. Accordingly, cellulose, glucomannan, and xylan were calculated using Eqs. (1–3): Cellulose = Glucose – Mannose/3.5 (1) Glucomannan =Mannose x (1+1/3.5) + Galactose (2) Xylan = Xylose + Arabinose

(3)

However, there is always a significant

TABLE 3

Test methods used for spent liquors.

Sulphate Lignin Acetone extract Sulphite Arabinose, galactose, glucose, mannose, and xylose Thiosulphate Total-S fraction of the pulp that cannot be analyzed and that is reported as ‘residuals’. The weight of these residuals is normally about 10% of bone-dry pulp weight, but can be up to 20%–30% in certain cases. In addition, there are two ways of presenting the results of a carbohydrate analysis: including one water molecule per monomer, or without including any water molecules at all. The monomeric values in this study are always given as the dehydrated weight, and the residuals in the carbohydrate analysis have not been included, which means that our figures for cellulose, glucomannan, and xylan are on the low side compared to the experiments reported in, for example, Rydholm [12]. Sulphite cooking acids are usually analyzed for total SO2, free SO2, and combined SO2, as determined by iodometric titration, followed by titration with NaOH. The total SO2 content of the cooking liquors takes into account free sulphur dioxide (SO2), bisulphite (HSO3-), sulphite (SO32-), thiosulphate (S2O32-), and polythionate (SnO62-) ions. The so-called combined SO2 value is a measure of the amount of cation (base) in the system and is defined

Fig. 3 - Lignin content in pulp versus cooking time during acid sulphite cooking of spruce and pine. Cooking conditions used were: 3.8% total SO2, 0.6% combined SO2, and a free SO2 content of 3.2%. L/W ratio was 4.6.

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SCAN-N 36 TAPPI T-UM 250 KA 11.305 SCAN-N 36 KA 10.202 SCAN-N 36 SCAN-N 35

as the amount of SO2 needed to produce XSO3 or X2SO3, where X is the cation, i.e., Ca2+, Mg2+, Na+, or NH4+ . RESULTS AND DISCUSSION

Figure 3 shows the lignin content versus cooking time at three different temperatures for acid sulphite cooking of spruce and pine. It is apparent that at the lowest temperature (132°C,) there was a relatively linear correlation between pulp lignin content and cooking time. At the next temperature (142°C), the cooking rate was higher, and the correlation between lignin content and cooking time was slightly curved at the end of the cook. At the highest temperature (154°C), the rate was still higher, and the curviness at the end of the cook was even more pronounced. The increase in lignin content at the end of the cook for the two highest temperatures was most probably due to lignin condensation reactions, for example when dissolved lignin became bound to lignin in the pulp fibers. That such reactions exist is well known, and it is also well known that they become more frequent after extended cooking if the cooking chemical concentration is too low. Earlier studies by Kaufmann and Ingruber also indicated the need to have a sufficient amount of combined SO2 in the system to avoid lignin condensation reactions [10,13]. The two types of pulps, i.e., spruce and pine pulp, in Fig. 3 show in reality the same general correlation, but the delignification rate is slightly higher in the spruce case. Hence, the delignification chemistry is probably very similar for spruce and pine, although pine is usually avoided in sulphite pulp mills due to the risk of lignin condensation reactions in its heartwood [1].

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Figure 4 shows that a black cook is obtained after a shorter cooking time if the temperature is increased. Hence, it is recommended that the cooking acid content should not be too low with respect to combined SO2, especially when operating at higher temperatures, because this will lead to lignin condensation problems. The lignin condensation reaction increases the molecular weight of the lignin, retarding delignification and eventually darkening the pulp. Figure 5 shows the lignin content in the two types of pulps versus cooking time for a cooking temperature of 154Â°C. The pine pulp starts at about 1.5% lower lignin content (26.6% in the wood sample) than the spruce pulp (28.0% in the wood sample), and this difference persists throughout the whole cooking time. Hence, it seems that if the two types of pulps had started at the same lignin content, the correlations in Fig. 5 would most probably have been identical, or in other words, pine and spruce seem to have the same lignin reactivity. According to Fig. 5, the identified lignin condensation reactions started at 2 h cooking time for both pulps. The remaining content of total SO2 was at this point about 0.5%, or 23 kg/t wood calculated as SO2. Because the starting concentration was 3.8% or 175 kg/t wood, this means

that 91% of the cooking acid was consumed at this point. Therefore, too low a concentration of cooking acid should be avoided, especially with high cooking temperature. Note that these cooking experiments were carried out just outside the critical black-cook area in the classical figure in Kaufmann [10]. The results in Fig. 5 can also be presented as in Fig. 6, with lignin content plotted against total SO2 concentration and including the three temperatures. Due to the limited number of data points, it was not possible to determine whether these three curves overlapped, but the three correlations were identical with a high degree of confidence. An increase in lignin content occurred below about 0.5% total SO2 (0.08 mol/l), indicating that lignin condensation reactions take place in a digester if the cooking chemical concentration becomes too low. Note also that the total SO2 content at which the lignin curves turn upward is the same for the spruce and pine samples. The corresponding figure for the pine pulp samples shows similar results. One conclusion is that lignin condensation reactions can take place both for pine and spruce during acid sulphite pulping. Lignin condensation reactions can also be obtained by thiosulphate coupling reactions [15]. It is well known that

Fig. 4 - Cooking temperature versus cooking time for acid sulphite cooking at 6% total SO2 and a L/W ratio of 4:1. The dotted line separates the cooking conditions for acceptable cooks and black cooks. The figure is taken from [14].

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thiosulphate ions and lignin can react to form thioethers [9,15], which can result in significant and hence problematic lignin condensation reactions. The thiosulphate level in these experiments was low (0.8 mmol/l, or about 0.1 g/l), and it can be assumed that part of the thiosulphate formed under the cooking conditions was consumed in side reactions with lignin. A sulphite pulp mill where the recycled cooking liquor contains dissolved lignin can withstand thiosulphate concentrations up to 5 g/l before process problems become obvious [12]. However, in our laboratory experiments where lignin condensation reactions were clearly occurring, i.e., at 154Â°C and at the longest cooking time, the thiosulphate content was as low as 0.4 mmol/l, or about 0.5 g/l. Figure 7 shows that the relationship between cellulose content and remaining cooking acid was unchanged down to about 0.5% total SO2, i.e., down to the same level where lignin condensation reactions occurred according to Fig. 5. Hence, at this point, there was an increase in lignin content and a decrease in cellulose content; both these reactions are unwanted from a process point of view. A decrease in cellulose content was also obtained at lower temperature, but at longer cooking time for pine pulp, as shown in Fig. 8. The trend is easiest to see for

Fig. 5 - Lignin content versus cooking time for two pulp samples at 154Â°C.

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the pine pulp; the spruce pulp showed no change in cellulose content at lower cooking temperature, as shown in Fig. 8. Pine and spruce wood showed similar cellulose degradation behavior at 154°C during the acid sulphite cook, as can be seen in Figs. 7 and 8 respectively.

Glucomannan and xylan are the two dominant hemicelluloses in softwood pulps, and what happens to these two hemicelluloses is of great importance for several reasons [1,2,5]. In a paper pulp, the hemicellulose content should be as high as possible for pulp yield reasons, but if the

Fig. 6 - Correlation between lignin remaining in pulp fibers and remaining cooking acid given as total SO2. The results are shown for the two pulp samples and at three temperatures.

Fig. 7 - Cellulose content versus remaining cooking acid for spruce and pine pulp samples at 154°C.

Fig. 8 - Cellulose content in pulp versus cooking time for spruce and pine pulp samples at three cooking temperatures.

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pulp will end up as a dissolving pulp used for viscose fiber manufacturing, hemicellulose content should be low as possible. In an acid sulphite cook, the glucosidic linkages of the polysaccharides are attacked by the acid, and some depolymerization of polysaccharides therefore cannot be avoided in the later part of the cook [17]. Cellulose is crystalline and therefore not severely attacked by the cooking chemicals, but the hemicelluloses are readily attacked because of their amorphous nature and low degree of polymerization (DP). The acid hydrolysis reactions degrade the hemicelluloses to a certain extent, and the liberated fractions are dissolved into the cooking liquor and are further hydrolyzed into monomers. Parallel to acid hydrolysis, other major reactions such as deacetylation, oxidation, and dehydration of hemicelluloses occur, resulting in furfural and hydroxymethyl furfural formation during cooking [18]. Figure 9 shows the glucomannan and xylan contents of pulp versus lignin content for cooking experiments with spruce and pine at 154°C. The two pulps followed the same correlation for glucomannan, but the xylan content was found to be slightly higher for the pine pulp. Due to lignin condensation reactions at the end of the cook, the final lignin content increased to about 10% from 5%. The hemicellulose contents of the two pulps decreased continuously, and both ended up at less than 1% hemicellulose. Hence, it can be concluded that the lignin and hemicellulose reactions are not correlated, at least not at the end of the cook. Figure 10 shows the acetone extractives content of the two pulps versus time at a cooking temperature of 154°C. The original pine wood contained more extractives than the original spruce wood. In the very first part of the cook, the extractives contents remained unchanged, although the lignin content was significantly reduced, as shown in Fig. 3. However, when the full cooking temperature had been reached (time “0 h”) and the delignification reactions had reduced the lignin content to about 20% (cf. Fig. 3), the extractives content started to go down according

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TRADITIONAL AREA CONTRIBUTIONS

Fig. 9 - Glucomannan and xylan content in pulps versus lignin content for spruce and pine pulp at 154°C cooking temperature.

Fig. 10 - Acetone extractives content in pulp samples versus cooking time for cooking experiments at 154°C.

to a relatively linear correlation. The pine pulp in our experiments always had higher initial extractives content, but the removal rate was also higher, meaning that the two pulp types obtained at the end of the cooking experiments had about the same final extractives content. Figure 11 summarizes the yield results for the pine cooking experiments. For comparison, our earlier results on the same raw material, but using bisulphite cooking at the same temperature (154°C) are also shown [20–23]. The hemicellulose content was almost totally eliminated in the acid sulphite case after 3 h cooking time, which is beneficial if the pulp is intended for dissolving pulp. In the bisulphite case, on the other hand, about 50% of the hemicelluloses were still present after three hours cooking time at the same temperature. Bisulphite cooking is therefore not recommended for production of dissolving pulps. It is also apparent that the lignin reaction rate is much higher in an acid sulphite cook than in a bisulphite cook at a given temperature and a given charge of total SO2. To obtain the same lignin reaction rate in the bisulphite cook, a higher temperature is a must [20–23]. Finally, a certain amount of extractives remains in the final pulp in the acid sulphite case, and even more so in the bisulphite pulp. Extractives content in the final pulp is a quality parameter—the lower the content, the better. Due to the acidic pH of a sulphite cook, the extractives are hard to eliminate, but they are much easier to remove in an alkaline stage such as a kraft cook [24]. When the acid sulphite and bisulphite pulp results are compared, it is clear that the hemicellulose and extractives contents are higher in the bisulphite case, which means, for example, that pulp yield is higher after bisulphite cooking at the same cooking temperature and the same cooking acid charge. CONCLUSIONS

Fig. 11 - Carbohydrate, extractives, and lignin contents versus cooking time and delignification during acid sulphite and bisulphite cooking of pine using laboratory-prepared cooking acid.

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Acid sulphite cooking of spruce and pine showed very similar reaction rates at the same temperature and cooking chemical charge. Lignin condensation reactions

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were observed when the total SO2 content was below 0.5% or 23 g/kg wood (0.08 mol/l); this minimum value was the same for spruce and pine. This critical concentration was also the same for all temperatures studied (132°C–154°C). At the point where lignin condensation became visible, the cellulose content started to decrease. The hemicellulose content decreased throughout the cook, whereas the lignin content initially decreased, but increased at the end after prolonged cooking. It was suggested that the lignin and hemicellulose reactions were connected at the beginning of the cook, but not at the end. The acetone extractives content was significantly higher in the pine wood than in the spruce wood, but its degradation rate was higher for the pine pulp. Hence, after 3 h cooking time, the extractives contents for the two types of pulps were approximately the same. ACKNOWLEDGEMENTS

This study was performed within the Industrial Graduate School VIPP (Values Created in Fiber-Based Processes and Products) program with financial support from the Knowledge Foundation, Sweden. Thanks are due to the financial contribution from Domsjö Fabriker and MoRe Research in Örnsköldsvik, Sweden. The authors are also grateful for the support of the project from the Kempe Foundations in Örnsköldsvik, Sweden, and for constructive criticism of the manuscript from Stefan Svensson of MoRe Research and Kristina Elg Christoffersson of Domsjö Fabriker.

Sixta, H., Süss, H.U., Potthast, A., Schwanninger, M., Krotscheck, A.W., Pulp bleaching. In: Sixta, H. (ed.) Handbook of Pulp, Vol 2. Wiley-VCH, Weinheim, Germany (2006). Annergren, G., Rydholm, S.A., “On the behaviour of hemicelluloses during sul-

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6. 7.

9. 10.

11. 12. 13.

REFERENCES 1.

14.

phite pulping”, Svensk Papperstidning, 62: 738 (1959). Rydholm, S. A., Lagergren, S., “On the delignification reaction of the technical sulphite cook”, Svensk Papperstidning, 62: 103–108 (1959). Patt, R., Kordsachia, O., Kopfinann, K., “Wirtschaftliche, technologische und ökologische Aspekte der Zellstoffherstellung nach dem ASAM-Verfahren”, Das Papier, 43(10), 108–115 (1989). Sixta, H., “Comparative evaluation of different concepts of sulphite pulping technology”, Das Papier, 52 (5): 239–249 (1998). Annergren, G., Germgård, U., “Sulphite pulping: Process aspects for sulphite pulping”, Appita, 67 (4): 270–276 (2014). Rueda, C., Calvo, A.P., Moncalian, G., Ruiz, G., Coz, A., “Biorefinery option to valorize the spent liquor from sulphite pulping”, J. Chem. Technol. Biotechnol., 90: 2218–2226 (2014) (wileyonlinelibrary.com). Zhu, Y.J., Subash Chandra, M., Gleisner, R., Gilles, W., Goa, J., Marrs, G., Anderson, D., Sessions, J., “Case studies on sugar production from underutilized woody biomass using sulphite chemistry”, TAPPI Journal, 14(9): 577–583 (2015). Sjöström, E., Wood Chemistry: Fundamentals and Applications. Academic Press, New York, USA (1993). Kaufmann, Z., “Über die chemischen Vorgänge beim Aufschluss von Holz nach dem Sulphite prozess”, ETH-Bibliothek, Zurich, Switzerland, 100 (1951). Meier, H., “Studies on hemicelluloses from pine”, Acta Chem. Scandinavia, 12(10): 1911–1918 (1958). Rydholm, S.A., Pulping Processes, Wiley, New York, USA (1965). Ingruber, O.V., Kocurek, M.J., Wong, A., Sulphite Science and Technology, Technical Section Canadian Pulp & Paper Association, Volume 4, Canada (1993). Shahzad, M.A., “Effect of temperature and time on acid sulphite cooking for dissolving pulp”, Master of Science thesis, Karlstad University, Karlstad, Sweden (2012).

15. Goliath, M., Lindgren, O.B., “Reactions of thiosulphate during sulphite cooking, Part 2: Mechanism of thiosulphate sulphidation of vanillyl alcohol”, Svensk Papperstidning 64(12): 469–471 (1961). 16. Ek, M., Gellerstadt, G., Henriksson, G., Pulp and Paper Chemistry and Technology, Book 1, Wood Chemistry and Wood Biotechnology (Ljungberg textbook), KTH, Stockholm, Sweden (2007). 17. Wenzl, J.F.H., The Chemical Technology of Wood, Academic Press, New York, USA (1970). 18. Iakovlev, M., SO2 Ethanol Water (SEW) Fractionation of Lignocellulosics, Diss. Finland: Dissertation, Aalto University (2011). Available: http://lib.tkk.fi/ Diss/2011/isbn9789526043142/ isbn9789526043142.pdf. 19. Lawoko, M., Henriksson, G., Gellerstedt, G., “Structural differences between the lignin-carbohydrate complexes present in wood and in chemical pulps”, Bio-macromolecules, 6(6): 3467–3473 (2005). 20. Deshpande, R., Sundvall, L., Grundberg, H., Germgård, U., “The Initial phase of sodium bisulphite pulping of spruce, Part I”, Cellulose Chemistry and Technology, 50(2): 293–300 (2016). 21. Deshpande, R., Sundvall, L., Grundberg, H., Germgård, U., “The influence of temperature on the initial phase of sodium bisulphite pulping”, O Papel, 76(4): 56–61 (2015). 22. Deshpande, R., Sundvall, L., Grundberg, H., Germgård, U., “Some process aspects on single-stage bisulphite pulping of pine”. Accepted for publication in Nordic Pulp and Paper Research Journal, March 2016. 23. Deshpande, R., Sundvall, L., Grundberg, H., Germgård, U., “The influence of different types of bisulphite cooking liquors on pine wood components”, BioResources Journal, 11(3): 5961–5973 (2016). 24. Mutton, D.B., “Wood extractives and their significance to the pulp and paper industry”. In: Hillis, W.E. (Ed.), Academic Press, New York, USA (1962).

Journal of Science & Technology for Forest Products and Processes: VOL. 6, NO. 2

2018 PAPERWEEK

CALL FOR PAPERS

CANADA

tré

al,

The Annual Conference of the pulp and paper industry in Canada

/F eb

-8

PaperWeek Canada, the premier Canadian gathering for the advancement of the pulp and paper and forest products industry, will be taking place February 5-8, 2018 at the Fairmont Queen Elizabeth Hotel in Montreal (QC, Canada). We encourage all industry leaders, mill personnel, suppliers, researchers and experts to submit their latest work for presentation in the program.

Where skills lead

to competitiveness

TOPICS OF SUBMISSIONS:

Business Leadership Safety Management Reliability Industry Leader Keynotes

Technical Innovation

w. pa

Bleaching Environment Energy Papermaking

ee kc

a.c

SUBMIT YOUR ABSTRACT BEFORE OCTOBER 1st, 2017

Sector Events

Convertech (converting) PulpEx (pulping) TechPack (packaging) Tissue Masters (tissue)

ABSTRACT SUBMISSION INFORMATION - In addition to the above main topics of submission, others are welcome (please specify) - Priority will be given to papers presented by mill personnel - Abstracts should not exceed 300 words - Abstracts should be sent by email at paperweek@paptac.ca before October 1st, 2017 - Once accepted, full papers should be submitted to the presentation platform (EPAC) by January 15th, 2018 - Speakers must register before January 15th, 2018 - The conference format allows for 20 min of presentation followed by 5 min Q & A - Late submissions might not be considered for the program - Full manuscripts will be considered for potential publication in our peer-reviewed journal J-FOR NB: It is understood that if your abstract is accepted, the main speaker is committed to participate at PaperWeek. No withdrawal from the program will be accepted, however, speaker replacements are allowed. All notices must be made in writing. www.paperweekcanada.ca

PAPTAC 740 Notre-Dame St. W., suite 1070, Montréal (Québec) H3C 3X6 CANADA Phone: (514) 392-0265 / Fax: (514) 392-0369 / WWW.PAPTAC.CA tech@paptac.ca

THE IMPACT OF WET END CHEMISTRY ON PAPER MACHINE PERFORMANCE - FUNDAMENTALS REVISITED ABSTRACT

PRZEM PRUSZYNSKI Paper production remains a physical process of filtering a papermaking furnish over a wire, forming a mat, and performing successive steps of vacuum dewatering and drying. With increasing forming section speed, development of new and challenging grades of paper, stringent quality demands, and increasingly important cost issues, wet-end chemistry has become more complex, and its general understanding has become very important. Variation in chemistry and undesired interactions between various chemical treatments may lead to numerous quality and runnability problems. One role of the chemical supplier is to assist papermakers with knowledge of these issues to avoid chemistry-related problems. This paper reviews basic wet-end chemistry factors and their impact on papermaking. Some original research data and mill observations are also included.

INTRODUCTION

Increased closure of water systems, more aggressive bleaching processes, higher deinked pulp content, and higher-shear forming sections in new and modern paper machines have resulted in increased contamination levels in the paper machine wet end. Variation in paper machine conditions leads to unstable wet-end operations and negatively affects machine productivity and product quality. Mechanical pulp-based systems, due to the extent to which they are integrated with pulping and bleaching operations, are particularly affected by system variability. All chemical programs are highly affected by changes in water chemistry. These programs include retention, drainage, deposit control, and strength applications. Factors that affect the performance of these programs also affect quality parameters such as formation, two-sidedness, gloss, opacity, and sheet printability. From a chemist’s point of view, the most important factors that influence paper machine wet-end chemistry are:

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• pH • Detrimental substances: o Conductivity o Cationic demand • Surface charge (zeta potential) • Hardness DISCUSSION pH

The major links between pH, paper machine performance, and paper quality are described below.

water phase. Dissociation of acid groups to their anionic form (COO-) is described by the pKa value. For most carboxylic acid groups, pKa is approximately 4.5–5. The change between the acid (uncharged) and salt (anionic) forms of a weak acid takes place in the pH range around its pKa (pKa – 2 ≤ pH ≤ pKa + 2), with the steepest change close to pH=pKa. With a pKa of 4.5, carboxylic acid functionalities are not only the source of most of the anionic charge in the system, but also represent an important

Charge development: anionic and cationic - Anionic charge in papermaking

systems originates from dissociation of acidic groups present on the solids and in the materials dissolved in the water phase. In papermaking systems, carboxylic groups (-COOH) are the most important acidic contribution to anionic charge. This anionic charge development leads to the presence of anionic soluble substances and of anionic charge on the surface of furnish components dispersed in the

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PRZEM PRUSZYNSKI

Global Technical Specialist Nalco Water: An Ecolab Company Napierville, IL, USA *Contact: ppruszynski@nalco.com

TRADITIONAL AREA CONTRIBUTIONS

• pH is an important factor affecting stability for grades operating in an acid pH range. • Neutral (pH = 6.8–7.4) and alkaline (pH=7.5–8.2) papermaking systems are always more anionic, but far less sensitive to charge variability than grades operating in an acid pH range.

Further consequences of pH impact on charge extend to areas such as the following: • Solubility of organic materials increases with pH. Charged species are more soluble in water. Hence, exposing fiber to higher pH results in increased content of soluble organic materials. • Level and variability of anionic detrimental substances affect the performance and stability of retention and drainage polymers. • Level and variability of surface charge on papermaking elements leads to variation in adsorption of additives, fiber swelling, and unstable strength and water retention values. • Changes in the amount of anionic charge alter the stability of colloidal dispersions of pitch and stickies. Variation in this stabilizing repulsive force explains the well-known pH shock impacts that often lead to massive pitch or stickies deposits. If this effect is the highest around pH=pKafor carboxylic groups, one could define downward pH change reaching pH <5 as the most detrimental “pH shock”. In that sense, it is important to monitor local pH variation around addition points of acidic materials as

Fig. 1 - Impact of pH on charge development by dissociation of carboxylic groups. This graph assumes pKa=5 for carboxylic groups and is based on the idealized single carboxylic group scenario.

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a potential source of initial colloidal destabilization. Anionic additives, including anionic retention polymers and dispersants, experience loss of anionic charge at lower pH. In the case of products with anionic charge derived from carboxylic acid groups, this anionic charge loss will be significant at pH<5. This may lead to performance deterioration and limits the pH range for use of anionic polymers. These polymers are a good choice for neutral or alkaline operations where their full anionic charge is effective. It is important to remember that charge on flocculants (cationic or anionic), in addition to its impact on adsorption, is primarily responsible for enabling their extended conformation in solution, which is relevant to their bridging capabilities. The cationic charge of most cationic additives originates from the presence of various amine functionalities and may also be pH-dependent. For primary, secondary, and tertiary amines, the cationic charge comes from their ammonium salts formed by protonation of the amine: RNH2 +H+

→

source of charge variability (Fig. 1). Figure 1 presents a slightly idealized case based on pKa=5 for a single carboxylic acid group. Neighbouring carboxylic acid functionalities impact their acidity, so that the real curve may be slightly flatter. Sulphonic (-SO3H), hydroxyl (-OH), and phenolic (PhOH) groups in papermaking systems do not play as significant a role as the carboxylic group. The sulphonic group is much more acidic (pKa <1) and will always be fully dissociated in the practical papermaking pH range. It always contributes to overall charge, but not to charge variability. Hydroxyl (pKa>14) and phenolic (pKa~10) groups are much weaker acids, and their dissociation takes place only at very high pH values, outside the practical papermaking range. These observations lead to important practical conclusions:

RNH3+.

The position of this equilibrium and charge development depends on the strength of the amine base and is described by the pKa of the corresponding ammonium salt (pKa RNH3+). With a pKavalue of around 9 for typical amines, the cationic charge starts to decrease slightly above a pH of 7, but decreases significantly at a pH above 8. In one interesting case of a newsprint machine operating with a blend of TMP and recycled fiber, loss of charge on coagulant related to conversion from acid to neutral pH operations led to significant loss of paper machine efficiency due to increased calender-stack deposition rates of pitch and stickies (1,2). Cationic additives with the quaternized amine functionality (R4N+) do not undergo acid-base equilibrium (no protonium attached to the nitrogen atom), and therefore their charge is pH-independent. It is strongly recommended, especially for true alkaline papermaking oper-

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ations (pH=8 and higher) to use quaternized cationic additives for the best performance level and stability (1,2). Impact on solubility of CaCO3 reactive fillers - CaCO3 fillers showslight solubil-

ity in water (KspCaCO3 = 10-10). Carbonate ion is then involved in a chain of reactions that are pH-dependent, leading finally to unstable H2CO3 and CO2 gas evolution at low pH. Evolution of CO2 makes this process irreversible and results in accumulation of Ca+2 ions in the system, which is measured as a hardness increase. Correcting pH drop will not correct this increase in water hardness, and it is important to pay constant attention to eliminate lower-pH areas, system-wide or local. This includes selection of proper operating pH targets, increased dilution at the feed points of low-pH additives, and elimination of microbiological issues leading to local pH drop. Proper broke management in CaCO3-containing papers and excellent microbiological treatment of broke have proven beneficial in several mill applications. Special attention must be paid when controlling pH using acids to avoid localized pH drops. Dilution of the acid and alum (at the addition point) and selection of a feed point with low CaCO3 filler concentration is recommended. The concern for excessive hardness development has also led to introduction of CO2-based pH

control technology. This is an excellent way of controlling pH to levels of pH>7.4 with limited Ca+2 development. If pH<7.4 is targeted, it becomes increasingly difficult (due to cost) to reach the target pH due to the weak character of carbonic acid. Impact of pH on solubility of fatty and resin acids - Fatty and resin acid con-

stituents are a part of natural extractives. These materials are typically a part of the outer layer of colloidal pitch particles, remaining in direct contact with the water phase and serving to stabilize the particles against agglomeration. At higher pH, the increasing anionic charge on the carboxylic groups of these acids increases their solubility. Therefore, both fatty and resin acids move out from the pitch particle to the solution. This process for resin acids takes place at much lower pH than for fatty acids (3). The need for additional energy to free the hydrophobic fatty acid chain from the hydrophobic interior of colloidal pitch particles significantly increases the colloidal pKa value for fatty acids. The presence of resin and fatty acids in soluble form creates opportunities for precipitation of their salts with Ca+2 and Mg+2 as an alternative agglomeration mechanism for pitch deposition (4). Brightness - Mechanical pulps undergo the well-known alkaline yellowing process

at higher pH levels. This is related to chemical changes in lignin structure. The sensitivity of this process increases with higher pH. With the trend to higher pH driven by the desire to use calcium carbonate fillers, the potential for brightness loss of mechanical pulp is increased. It is well known that the change from acid to neutral pH (typically pH=5 to 7) results in loss of about two brightness points (5). Use of higher-brightness CaCO3 fillers (PCC or GCC) and the increased filler content possible due to increased sheet strength at higher pH justify this initial brightness loss. To accommodate carbonate fillers, a minimum pH of 6.8â&#x20AC;&#x201C;7.0 is required. Higher pH may result in unnecessary brightness losses that will require increased dosages of bleaching chemicals. The sensitivity of mechanical pulp brightness to pH differs among wood species and the type of brightening technology used. Allison and Graham (6) discussed the alkaline darkening phenomenon and its mechanisms for Radiata pine-based pulps (6). For highly sensitive virgin mechanical pulps, losses of up to six brightness points between a pH of 7 and 7.8 were cited. The actual value may not always be this high, but it is always recommended to optimize pH to minimize its impact on brightness. For high-brightness mechanical pulps, even one point of brightness loss translates to significantly higher bleaching costs (up to $10/t) and consequent wet-end contamination. It is important to understand that mechanical pulp-containing grades, especially virgin pulps, require operation in a narrow pH band to control calcium carbonate dissolution (required pH>6.8) and reduce the impact on brightness (required pH<7.2). It is worth mentioning that for recycled mechanical pulp furnish, brightness sensitivity is lower, enabling operation at pH values up to around 7.8. Hydrolysis reactions - Organic com-

Fig. 2 - Carbonate species distribution as a function of pH. Calcium carbonate solubility, quantified by Ksp, feeds this system with carbonate ion.

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pounds, derivatives of carboxylic acids (esters, amides, acetals, and ketenes) undergo a reaction with water (hydrolysis) that is most effectively catalyzed with bases, a process known as base-catalyzed hydrolysis. In this category, specific base catalysis with HO-

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is a dominant mechanism. The rates of these hydrolysis reactions increase with pH. Examples of the hydrolysis reaction from a papermaker’s point of view can be hydrolysis of ASA (anhydride) or AKD (ketene dimer), leading to formation of dicarboxylic acid (ASA) or ketone (AKD). These hydrolysis reactions compete with the reaction with fiber, leading to sizing development. Dicarboxylic acid is not only considered as a de-sizing agent, but can also react with hardness, leading to persistent Ca salt deposits. Ketone formed from hydrolyzed AKD leads to lower coefficient of friction and related process issues. In general, in uncoated free-sheet grades, hydrolysis of sizing materials defines the upper limit of operating pH. Exceeding a pH of 8.0–8.2 in these grades leads to reduced sizing effectiveness, formation of deposits, or problems with slippery pulp. Detrimental substances

Detrimental substances that accumulate in the paper machine water system can be divided into two groups: • Simple salts, as measured by conductivity. Salts have very little affinity for the formed paper web, and their degree of accumulation is closely related to the degree of closure of machine water circuits.

• Polymeric anionic substances, which increase the cationic demand of the system due to their ability to interact with cationic polymers. Several authors have discussed mechanisms of deactivation of cationic additives by detrimental substances (7–11). CONDUCTIVITY Impact on retention and drainage

Conductivity is a convenient measure of the concentration of simple, mobile ions in a papermaking system. Because many papermaking processes involve interaction between colloidal species and polyelectrolytes, knowledge of the ionic strength of a solution is very important. Simple electrolytes significantly impact the state and stability of colloidal matter and define interactions between charged species in solution. Ions, measured as conductivity, contribute to reduced repulsion of like charges on flocculants and reduce their extension in solution. Because these polymers operate through bridging flocculation, which depends on their effective length in solution, their performance in terms of retention and drainage is affected at higher conductivity levels. There is much information in the literature on the impact of conductivity on various aspects of papermaking processes. Dobbins and Alexander (12), Davison

Fig. 3 - Operating pH ranges based on the pulp, filler, and sizing technology used.

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(13), Lindstrom and Wagberg (14), Miyanishi et al. (15), Hulkko and Deng (16), Allen et al. (17–19), and Englezos et al. (20) have reported various observations regarding the impact of ionic contaminants on papermaking processes. Pruszynski and Jakubowski (21) presented a detailed and systematic study on the impact of conductivity on the performance of retention programs, measured in terms of chemically induced drainage. A TMP furnish was used as a model system and was spiked with several levels of various ions. To evaluate their impact on conductivity, NaCl and Na2SO4 were used as model ionic contaminants. Free drainage in a “clean” system was measured for untreated samples and samples treated with a retention program. The increase in drainage due to treatment was taken to represent the performance of the retention program in the absence of ionic contamination. Using the same dosage of the retention program, drainage was then measured at various levels of contamination with model substances. Results were presented in terms of percent initial drainage gain as a function of ionic contamination or conductivity. Significant loss of chemically induced drainage was observed for most typical retention programs. In many cases, all benefit of chemical application was lost at high conductivity levels. A combination of bentonite followed by cationic flocculant (CPAM) (this order of addition was very relevant) showed different results, with an initial increase in drainage at higher conductivity (Fig. 4). Although bentonite has been used in papermaking for at least 40 years, the mechanism of its action is not yet fully understood. Lindstrom suggests formation of a network between bentonite and polyacrylamide polymer that decreases the solubility of the polymer, increasing its adsorption and enabling sweeping of colloidal particles from the water phase (22,23). Observations from Fig. 4 can be explained by bentonite participation in the bridging mechanism of flocculation. Considering the size of bentonite platelets (in the 0.5–2 μm range in the x-y plane) and the combination of anionic and cationic charges on

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removal of water bound with the fiber (WRV), different impacts may be observed in the early phase of forming (typically less drainage) and pressing (improved dewatering). The final net impact on overall water removal depends on a number of factors, but close attention to conductivity level, variability, and sources of variation is strongly recommended to achieve better understanding and control of paper machine performance. Impact on starch retention and sizing

Fig. 4 - Impact of conductivity on chemically induced drainage for single-flocculant, dualpolymer, and bentonite-containing programs.

its surface, bentonite may be considered as an amphoteric retention polymer that can participate in bridging flocculation (Fig. 5). By contributing to bridging, bentonite reduces overall system sensitivity to conductivity because its rigid structure does not undergo conformational changes (coiling) under high conductivity. Instead, increased conductivity benefits drainage by reducing the double-layer thickness, which makes bridging more effective and reduces water retention (24). A practical illustration of the impact of conductivity on the performance of a retention program was provided by Gratton (25). For a paper machine operating with an on-line closed-loop control strategy, a five-fold increase in retention aid dosage was required when the conductivity changed from 1000 to 5000 ÎźS/cm. Observations reported in the cited literature are not always consistent in every detail, but clearly indicate that conductivity change affects drainage and retention on the paper machine. The extent of this impact in quantitative terms depends on several factors. Conductivity increase promotes water removal from fiber by affecting its swelling and consequently its water retention value (WRV) but reduces

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chemically promoted drainage by negatively affecting the performance of retention and drainage programs. Because conductivity affects interactions among charges, its impact on WRV increases with pH and follows negative charge development in the fiber structure. In acid pH processes, the amount of charge on the fiber is low, and the impact of conductivity is less than in neutral and alkaline papermaking. Because conductivity impacts flocculationdriven drainage negatively, but promotes

Increasing conductivity also impacts starch adsorption. This was well documented by Gratton (26) in his study of ASA sizing at different conductivity levels. HST values dropped from around 300 s to 50 s when conductivity increased from 1000 to 3000 ÎźS/cm. The authors also determined that higher-charge (DS) starches reduced the negative impact of conductivity. Increased conductivity reduces the repulsive forces that are responsible for stability of colloidal dispersions, possibly leading to their destabilization, especially in the presence of high shear forces. Pitch particles exposed to the high pH of hydrogen peroxide bleaching are depleted of steric stabilization, and their stability becomes very sensitive to charge repulsive forces impacted by conductivity and hardness levels. The main control strategies related

Fig. 5 - Proposed mechanism of bentonite operation.

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TRADITIONAL AREA CONTRIBUTIONS

to conductivity remains controlling the levels of generated ionic contaminants, especially in highly closed systems. In addition, careful selection of products and application strategies can reduce the impact of conductivity on program performance. SYSTEM CHARGE

Charge in papermaking systems is generally characterized in two ways: cationic demand and zeta potential. In mill practice, these two charge measurements are not always clearly differentiated. The type of charge measurement used in a particular mill often may not fit the mill’s specific operating needs. Cationic Demand

Cationic demand describes the total content of anionic substances available for reaction with cationic additives and is therefore a function of both individual species charge levels and their concentration. Measurement of cationic demand always includes titration with a standard solution of cationic polymer (typically 10-3N polyDADMAC) along with various methods to determine the equivalent point of titration (from dyes to the popular piston devices). Substances that are measured by cationic demand titration must be anionic and have a partial polymeric character that makes them sparingly soluble in water and able to interact with cationic polymers. Hydrogen peroxide-bleached mecha-

nical pulps are a case of extremely high levels of generated cationic demand. Pruszynski et al. (27) discussed sources and available control strategies for reducing and destabilizing cationic demand in these systems. Use of coagulants, improved pulp washing (thickening), changes to high-consistency bleaching, and replacing NaOH with Mg(OH)2 as a source of alkalinity in the bleaching process are all effective approaches, but they come with negative effects such as generation of detrimental polyelectrolyte complexes, process yield losses, energy losses, lower strength, and lower brightness. The unique effectiveness of pectinase enzymatic application was then demonstrated based on mill applications. Pectinase was chosen based on the excellent work by Thornton (28,29) that identified poly-galacturonic acids as a source of about 50% of total cationic demand measured in these systems. Polygalacturonic acids are formed by hydrolysis of their methyl esters (pectins) in the high-pH environment of the hydrogen peroxide bleaching tower. Depolymerization of these natural polymers leads to their increased solubility in water, resulting in loss of reactivity towards cationic additives. Pectinase requires pH<5.5 to be fully effective. Under appropriate conditions in a full-scale machine application, a dosage of pectinase between 40 and 80 g/t provided a drop in cationic demand from approximately 1500 μEq/l to around 700 μEq/l (Fig. 6). This change

Fig. 6 - Use of pectinase to control cationic demand in a newsprint application using a hydrogen peroxide-bleached dilution water stream.

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Fig. 7 - Impact of changes in sulphate ion concentration on drainage at two levels of cationic demand controlled by addition of polygalacturonic acid (PGA).

was equivalent to using more than 10 kg/t of a typical coagulant for charge neutralization. Pruszynski (21) also studied the combined effect of conductivity and cationic demand. In these experiments, conductivity and cationic demand were controlled by adding Na2SO4 and polygalacturonic acid respectively. An experimental design approach was used to study the mixed effects of both variables. Results indicated that sensitivity to conductivity in terms of drainage loss was higher when the system was already stressed by higher cationic demand (Fig. 7). Zeta Potential

Zeta potential, in simple terms, is a measure of the charge of an individual particle. This is very important information that affects the application of retention programs, strength additives, and sizing applications, especially in cases with a low amount of protective soluble anionic charge in solution, which can easily become over-cationized. Zeta potential measurement is typically based on electrokinetic principles, with electrophoretic mobility and streaming current (or potential) being the most popular. Unfortunately, there is no reliable on-line zeta potential measurement. Some streaming current-generating devices are

Journal of Science & Technology for Forest Products and Processes: VOL. 6, NO. 2

applied, but their response must be corrected for conductivity changes. HARDNESS

Ca+2 and Mg+2 ions, in addition to their contribution to overall system conductivity, impact papermaking systems in very specific ways. Salts of calcium and magnesium are less soluble than those of sodium and potassium. This applies to salts with both organic and inorganic acids. There are several potential sources of calcium ions in paper and board applications. Hardness developed from exposure of CaCO3 filler to lower pH is one type that papermakers can control (discussed in the section on pH). Hardness coming with the water source or from recycled material is more difficult to overcome. It is worth mentioning that paper or board products made in a high-hardness environment contain all hardness present after the press section (typically about 50% solids) after the remaining water is evaporated. Bringing this hardness back to highly closed papermaking systems significantly increases steady-state hardness levels. Pitch and stickies deposits

As briefly discussed earlier in this paper, calcium ions have a strong tendency to form salts with carboxylic groups in the system. This reduces the stabilizing negative charge on organic colloids and may trigger their deposition. This process operates on the surface of the colloidal particle and with the soluble resin and fatty acids present in the system. At pH values of 5.5 and higher, the concentration of carboxylate groups (COO-) is sufficient to contribute to deposition. Impact on fiber surface properties

Yuan et al. (30) discuss adsorption of Ca+2 ions on the surface of fibers and their impact on the performance of retention, strength, and sizing applications. The charge-screening effect of calcium ions leads to reduced anionic charge and affects adsorption of cationic starch, cationic strength additives, and sizing. The presence of calcium ions is an

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important factor affecting white-water system closure problems. Every source of additional Ca+2 ion will accumulate in the system. At 95% closure, an accumulation factor of approximately 20 times applies and a source of 5 ppm Ca+2 will result in a steady-state level of about 100 ppm. CONCLUSIONS AND PRACTICAL REMARKS

• pH, conductivity, cationic demand, zeta potential, and hardness impact retention, drainage, deposit formation, sizing, and strength additives, which in turn affect machine stability, efficiency, and product quality. • Collecting relevant wet-end chemistry data with on-line equipment is recommended. These data must be correlated with machine performance information like retention, tray consistency, drainage, turbidity, etc. • Installation of conductivity probes at the white-water tray is always recommended. Identification of major contributions to overall conductivity level and variability requires initial checks of individual blended streams of furnish with a handheld conductivity unit. In some cases, it may be justified and recommended to install additional conductivity probes further back in the system. • For cationic demand, zeta potential, and hardness, where on-line sensors are either not readily available or expensive, frequent laboratory evaluations should be performed to determine the need for further investment in on-line equipment. • Wet-end performance must be stabilized before attempting to place retention programs on closed-loop control. Excessive system variability would lead to variations in retention-aid dosage control, affecting efficiency and causing changes in product quality. • For the chemical supplier, performing stability audits and gathering wetend chemistry data provide the opportunity to develop industry norms and best practices that will greatly benefit

papermaking operations. REFERENCES 1.

4. 5.

6. 7.

10. 11.

12.

13.

Dechandt, A., Watkins, T., and Pruszynski, P., “Total approach to deposit control on newsprint machine using TMP and DIP pulp mix - from specialized fixation of individual pulps to retention”, Appita, 57(1), 114 (2006). Richardson, D., Waller, N., Parsons, T., Stallard, J., Young, M., Watkins, T., and Dechandt, A., “Optimization of neutral papermaking wet end chemistry for pitch free newsprint manufacture”, Proceedings, Appita Conference, p. 219 (2003). Mclean, D., Vercoe, D., Stack, K., and Richardson, ”The colloidal pKa of lipophilic extractives commonly found in Pinus Radiata”, Appita, 58(5), 362 (2005). Back, E.L. and Allen, L.H., “Pitch Control, Wood Resin and Deresination”, TAPPI Press, Atlanta, 2000. Evans, B. and Slozer, M., “Neutral groundwood papers: Practical and chemical aspects”, Proceedings, 5th International Paper & Coating Symposium (2003). Allison, R. and Graham, K., “Kinetics od Alkali Darkening of TMP from Radiata Pine”, JPPS, 16(1), 28 (1990). Pelton, R., Allen, L., and Nugent, H., “A survey of potential retention aids for newsprint manufacture”, Pulp and Paper Canada 81(1), 54 (1980). Tay, C., “Application of polymeric flocculant in newsprint stock systems for fines retention improvement” TAPPI J., 63(3), 64 (1980). Philipp, B. and Lang, H., “Complexes of Cellulose Xanthate and Carboxymethyl Cellulose with cationic polyelectrolytes, especially polyethyleneimine”, TAPPI J., 52(6), 1179 (1969). Phillip, B., Zell. Pap., 25(4), 102 (1976). Linhart, F., Auhorn, W., Degen, H., and Lorz, R., “Anionic trash: controlling detrimental substances”, TAPPI J., 60(10), 79 (1987). Dobbins, R. and Alexander, S., “The physical and optical properties of paper made at high salt concentration”, TAPPI J., 6(12), 121 (1977). Davison, R., Proceedings, TAPPI Papermakers Conference, 171 (1985).

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TRADITIONAL AREA CONTRIBUTIONS

14. Lindstrom, T. and Wagberg, L., “Effects of and electrolyte concentration on the adsorption of cationic polyacrylamides on cellulose”, TAPPI J., 66(6), 83 (1983). 15. Miyasnishi, T. and Shigeru, M., “The effect of mill closure on the flocculation of various retention aid chemicals”, TAPPI J., 84(3), (2001). 16. Hulkko, V.-M. and Deng, Y., ”Effects of water-soluble inorganic salts and organic materials on performance of different retention aids”, JPPS, 25(11), 378 (1999). 17. Allen, L., Polverari, M., Levesque, B., and Francis, W., “Effects of system closure on retention- and drainage-aid performance in TMP newsprint manufacture”, TAPPI J., 82(4), 188 (2001). 18. Laivins, G., Polverari, M., and Allen, L., “Performance of poly(ethylene)/cofactor retention aids in mechanical pulps furnishes”, TAPPI J., 84(3), (2001). 19. Polverari, M., Allen, L., and Sithole, B., “Effect of system closure on retention and drainage aid performance in TMP newsprint manufacture-Part II”, TAPPI J., 84(3), (2001).

20. Trigylidas, D., Englezos, P., and Thornburn, I., ”The use of a fixative in conjunction with poly(ethylene oxide) for enhanced retention”, TAPPI J., 84(7) (2001). 21. Pruszynski, P. and Jakubowski, R., “Understanding sensitivity of retention programs to wet end chemical contamination in TMP-based newsprint furnish”, Appita, 59(2), 114 (2006). 22. Lindstrom, T., Soremark, C., and Martin-Lof, S., “The importance of electrokinetic properties of wood fiber for papermaking”, TAPPI J., 57(12), 94(1974). 23. Lindstrom, T. and Soremark, C.J., “Adsorption of Cationic Polyacrylamides on Cellulose”, Colloids and Interface Sci., 55(2), 305 (1976). 24. Lindstrom, T., “Chemical factors affecting the behaviour of fibres during papermaking”, Nordic Pulp and Paper Research Journal, 4, 191 (1992). 25. Gratton, R., Doiron, B., and Chen, G., “Impact of Pulp Mill Contaminants on the Wet End Chemistry of a Fine Paper Machine”, TAPPI Minimum Effluent

Mills Symposium, 225 (1997). 26. Beaudoin, R., Gratton, R., and Turcotte, R., “Performance of Wet-End Cationic Starches in Maintaining Good Sizing at High Conductivity Levels in Alkaline Fine Paper”, JPPS, 21(7), 238 (1995). 27. Pruszynski, P., Sherman, L., Wong-Shing, J., Quinn, M., and Kamlin, B., “Managing Anionic Detrimental Substances in Peroxide Bleaches Mechanical pulps – Unique Benefits of Enzymatic Treatment”, Appita, 64(2), 168-174 (2011). 28. Thornton, J., Ekmann, R., Holmbom, B., and Eckerman, C., “Release of potential “anionic trash” in peroxide bleaching of mechanical pulp”, Paperi ja Puu, 75(6), 426 (1993). 29. Thornton, J., “Enzymatic degradation of polygalacturonic acids released from mechanical pulps during peroxide bleaching”, TAPPI J., 77(3), 161 (1994). 30. Yuan, G., Dai, H., Ye, C., Zhang, Y., and Wang, Z., “Adsorption of Ca(II) from aqueous solution onto cellulosic fibers and its impact on the papermaking process”, Bioresources 6(3), 2790 (2011).

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