Covering Best Practices for the Industry
Sulfuric Acid T
O
D
A
Y
www.H 2S0 4Today.com
Spring/Summer 2020
Simplot ups its game at Wyoming acid plant Page 7
IN THIS ISSUE > > > > Market Outlook: The China challenge page 10
Improved tank vent emission control page 12
Detecting real-time moisture leaks in acid plant process gas Page 32
Clean Technologies
Making everyday life better, safer, cleaner For 100 years, we have partnered sulfuric acid producers with innovative technology and expert trouble-shooting technical support. And our tradition of designing advanced solutions to solve site-specific challenges continues – so we can together deliver cleaner air productively, efficiently and reliably. Learn more on www.cleantechnologies.dupont.com
MECS® Sulphuric acid & environmental technologies Copyright © 2019 DuPont. The DuPont Oval Logo, DuPont™, is registered trademarks or trademarks of E.I. du Pont de Nemours and Company or its affiliates. All rights reserved.
Sulfuric Acid
COVERING BEST PRACTICES FOR THE INDUSTRY
Sulfuric Acid T
O
D
A
Y
www.H 2S0 4Today.com
Spring/Summer 2020
Simplot ups its game at Wyoming acid plant Page 7
T
Vol. 26 No. 1
O
D
A
Covering Best Practices for the Industry
Y
Spring/Summer 2020
IN THIS ISSUE > > > > Market Outlook: The China challenge PAGE 10
FROM THE PUBLISHER
Improved tank vent emission control PAGE 12
Process gas dew point/moisture leak detection measurement system PAGE 32
On the Cover … 7
Simplot completes multiphase upgrade to Rock Springs, WY, acid unit
Departments 4
Industry Insights
News items about the sulfuric acid and related industries
16 Lessons Learned
Case histories from the sulfuric acid industry
36
Faces & Places
Covering sulfuric acid industry events
Dear Friends, Welcome to the Spring/Summer 2020 issue of Sulfuric Acid Today. We have dedicated ourselves to covering the latest products and technology for those in the industry, and hope you find this issue both helpful and informative. As we put this issue to press, many companies and individuals in the sulfuric acid industry are being affected by the coronavirus (COVID-19)–so far we have seen a significant impact on China’s industrial activities, with the flow of many commodities, raw materials, and other goods hampered. Many industrial sites are also facing shutdowns due to lack of labor amid widespread quarantines. One of the impacts on the sulfuric acid market thus far has been a decrease in domestic demand for sulfuric acid. This has been occurring while sulfuric acid production from China’s base metal (mainly copper) smelters does not appear to have been as impacted as the consumption side. See Acuity Commodities’ article on page 10 for further information. The rapid spread of the coronavirus is projected to continue through the third quarter of 2020, or longer, and will have a mixed impact on the sulfuric acid industry. Manufacturers are seeing supply chain disruptions, changing demand patterns, and staffing crunches due to social distancing and illness. Other challenges have been the restriction of non-personnel at the plant, which has forced some companies to push back their turnarounds to the fall; this can have an impact should the vendors and service companies already have commitments scheduled for that time. COVID-19 has also affected industry conferences and meetings, including our Australasia Sulfuric Acid Workshop. Due to restricted international travel, our meeting has been rescheduled to Sept. 20-23. See more information about the Australia sulfuric acid workshop on page 34. The organizers of the AICHE-Clearwater Conference, scheduled for June
10
The China challenge
EDITOR April Kabbash
12
Improved tank vent emission control
EDITOR April Smith
14
Sulfur gun improvements
18
Weir Minerals launches three new Lewis® pumps in major
20
Developing and maintaining a working at heights program
DESIGN & LAYOUT
22
How does sulfur purification affect opex of an acid plant?
24
Wet electrostatic precipitators: the proven technology for
281-545-8053
SUBSCRIPTIONS U.S. Plant Personnel —‑Complimentary U.S. Subscription —‑ $39 per year (2 issues) Internat’l Subscription —‑$59 per year (2 issues) Subscribe Online: www.h2so4today.com
12
product-line expansion
Marketing ASSISTANT Tim Bowers
Mailing Address: P.O. Box 3502 Covington, LA 70434 Phone: (985) 807-3868 E-Mail: kathy@h2so4today.com www.h2so4today.com
Sincerely, Kathy Hayward
FEATURES & GUEST COLUMNS
PUBLISHED BY Keystone Publishing L.L.C. PUBLISHER Kathy Hayward
12-13, are currently monitoring the COVID-19 virus and government requirements and will post updates on their website www.aiche-cf.org. Our thoughts are with all those in the industry who are affected by the coronavirus. We have compiled our Spring/Summer 2020 issue with articles and information we feel will be beneficial to your profession. Please see informative articles such as: Improved tank vent emission control (page 12); Sulfur gun improvements (page 14); Weir Minerals launches three new Lewis® pumps in major product-line expansion (page 18); Developing and maintaining a working at heights program (page 20); How does sulfur purification affect opex of an acid plant? (page 22); Wet electrostatic precipitators: the proven technology for sulfuric acid gas cleaning (page 24); Further reflections of an acid cooler technical representative (page 26); CSX™: A modern solution for sulfuric acid plant piping (page 28); Inline sulfuric acid monitoring (page 30); and detecting real-time moisture leaks in acid plant process gas (page 32). I would like to welcome our new and returning Sulfuric Acid Today advertisers and contributors, including: Acid Piping Technology Inc., Acuity Commodities, Alphatherm Inc., Beltran Technologies, Begg Cousland, Breen Energy Solutions, Central Maintenance & Welding, Chemetics Inc., Clark Solutions, Conco Industrial, DuPont MECS, Howden Turbo, Integrated Turbomachinery, Koch Knight LLC, Mercad Equipment Inc., NORAM Engineering & Constructors, Optimus, SensoTech, Southwest Refractory of Texas, Spraying Systems Co., Sulphurnet, VIP International, and Weir Minerals Lewis Pumps. We are currently compiling information for our Fall/Winter 2020 issue. If you have any suggestions for articles or other information you would like included, please feel free to contact me via email at kathy@ h2so4today.com. I look forward to hearing from you.
28
sulfuric acid gas cleaning 26
Further reflections of an acid cooler technical representative
28 CSX™: A modern solution for sulfuric acid plant piping 30
Inline sulfuric acid monitoring
32
Detecting real-time moisture leaks in acid plant process gas
34
Sulfuric Acid Today to host sulfuric acid workshop in Brisbane, Queensland
32
Department
Industry Insights Copper, sulfuric acid markets affected by COVID-19
HAMBURG, Germany—Diminished demand for copper and sulfuric acid due to the COVID-19-induced shutdown is leading to growing inventories. In a recent letter to customers, Germany-based recycledcontent copper producer Aurubis said that by February, “The impacts of coronavirus, or COVID-19, had a firm grip on the copper market.” Specifically to the copper sector, “COVID-19 continued to influence copper production in February, especially in China,” according to Aurubis. Citing S&P Global Platts, the red metals firm says portions of the copper processing industry in China are currently producing at 60 to 90 percent of their normal level. Daye Nonferrous, based in Huangshi at the heart of the novel coronavirus outbreak in Hubei province, planned to operate at just a moderately reduced rate of 70-80 percent of capacity for the first quarter, a company source said. Daye Nonferrous’ 600,000-tonneper-year smelter in Huangshi City, Hubei, resumed operations in early February following the Lunar New Year holiday, despite being under quarantine and transport restrictions. The move echoes a trend across China’s
copper industry. Although demand for the metal has slumped on prolonged factory closures, smelters are reticent to incur the costs of more drastic production cuts. On the pricing side, “News about the impacts of the coronavirus continued to strain the price trend,” Aurubis wrote. On terminal markets, copper closed February at about $5,573 per metric ton, or $2.53 per pound, according to the firm. Concerning red metal supply, some primary smelters were facing pressures because of the global slowness caused by COVID19-affected regions. One smelter “was faced with the challenge of finding customers for its sulfuric acid output,” writes Aurubis. Nonetheless, finished copper inventories in global warehouses “made a significant leap in February,” standing at 550,000 metric tons at the end of the month. That figure is about 184,000 metric tons higher—a 50 percent boost—compared with 29 days earlier. At these rates of operation, expectations are for copper cathode inventories to build up over the coming weeks because copper fabricators remain on extended closures and demand for the metal is limited. “[The] government has ordered that plants should not reopen, which also includes semi-fabricating plants and enduser companies. Physical consumption is therefore virtually dead,” specialist copper market consultancy Simon Hunt Strategic Services said. The logistic and economic gridlock in
THE BREEN-SA PROBE
Real-time Moisture Leak Detection & Periodic Acid Dew Point Measurement SULFURIC ACID PROCESS EQUIPMENT PROTECTION • Moisture Leak Detection • Periodic Dew Point Measurement • Economizer Water Tube Temperature Control
COPPER SMELTER APPLICATIONS • Control of Weak Acid Production • Control of Sulfurization Air • ESP Performance
Breen Sensor Technology
AcidDewpoint.com
Patent pending
PAGE 4
Breen is a Mississippi Lime FGT Business Unit Company.
China caused by the coronavirus outbreak is having a heightened impact on copper above many other commodities because the country is by far the largest refined producer and consumer as well as a major net importer of raw materials. China produced 17.15 million tonnes of copper semi-fabricated products in 2018–76 percent of the world’s total, according to the World Bureau of Metal Statistics. Meanwhile stores of sulfuric acid, produced as a byproduct of smelting copper, zinc, and lead concentrates are building up as the plants that normally consume it are shut down. Hubei province, now mostly on lockdown, consumes over 20 percent of domestic sulfuric acid output in China. Its annual consumption is around 20 million tonnes, a local smelter source estimated. Sulfuric acid output from some of the biggest copper smelters—including Tongling Nonferrous, China Gold’s Sanmenxia and Jiangxi Copper as well as some smelters from northern China—used to be sold to Hubei consumers, mainly producers of fertilizers and chemicals. For more information, please visit www. aurubis.com.
Sherritt exits Ambatovy joint venture
MADAGASCAR — Sherritt International Corp is set to exit the Ambatovy joint venture in Madagascar, but its decision will not affect nickel or cobalt production at the mine, the Canadian company confirmed to Fastmarkets recently. The Canadian miner announced that it would not fund its 12 percent stake in the Ambatovy JV with Japan’s Sumitomo Corp and South Korea’s Korea Resources Corp (Kores), to protect Sherritt’s balance sheet after Ambatovy made a cash call to boost its short-term liquidity. Sherritt subsequently announced that it had become a defaulting shareholder. First refusal to fund Sherritt’s 12 percent share in Ambatovy will now pass to Sumitomo and Kores, while Sherritt itself will lose voting rights and influence on operations at a local level as per the terms of a default under the shareholders agreement. The Ambatovy mine, which produced 33,733 tonnes of refined nickel and 2,900 tonnes of refined cobalt in 2019, will reportedly continue to produce after Sherritt’s proposed exit, details of which are scheduled to be announced in late April. “Nickel and cobalt production at Ambatovy will not be [affected] by the transaction or pending timelines,” director of investor relations and communications, Joe Racanelli, said. Depressed nickel prices have undoubtedly exacerbated the issue, shaping the company’s belief that selling its 12 percent share in the Ambatovy JV would be the best way to protect its liquidity. The London Metal Exchange three-month nickel price continues to languish below $13,000 per tonne on March 10, despite hitting a three-week intraday high of $12,995 per tonne. Refined nickel production from later-
itic ore requires a significantly higher LME three-month price when compared to the capex cost of production, with multiple miners citing an LME three-month nickel price of $20,000 per tonne as an equitable level for lateritic production. “The transaction involves a number of components, including the exchange of $588 million of existing bonds for a new secured second lien note and the exchange of $145 million of CFA loans owed to our Ambatovy joint venture partners for our 12 percent equity interest, or a new amended loan. The transaction, pending approvals from all stakeholders, is slated to close by April 30, and will reduce Sherritt’s debt by approximately $415 million,” Racanelli said. For more information, please visit www. ambatovy.com.
India base metals mixed as markets assess coronavirus spread
NEW DELHI—Futures contracts of base metals have been mixed on the Multi Commodity Exchange of India and the London Metal Exchange recently as investors assessed developments surrounding the spread of coronavirus, analysts said. “The recovery movements on the metals markets appears to have been running out of steam. Traders seem to be fluctuating between optimism and pessimism regarding the COVID-19 virus, and are unsure about which direction to take,” Commerzbank AG said in a note. “While giving its semi-annual report yesterday, the world’s largest mining company warned of negative consequences for the Chinese and global economies, as well as for commodities demand, if the virus is not demonstrably well contained within the current quarter,” the German bank added. A Shanghai Metals Market survey showed the output of copper cathodes in China is expected to fall to 689,300 tn this month, down 5 percent from the previous month as smelters in the country struggle to store sulfuric acid.
Shanxi Zhongtiaoshan Nonferrous to undertake maintenance for 2 months
SHANGHAI—It was recently announced that copper producer Zhongtiaoshan Nonferrous Metal will conduct maintenance from the second half of March to the end of April. The Shanxi copper smelter, with annual capacity of 100,000 mt, brought forward the maintenance, after a slew of rivals in China trimmed production on excessively high inventories of smelting byproduct sulfuric acid. Production curtailments, however, have failed to deter copper inventories in China from growing, as demand from processors and end-users recovered slowly amid the ongoing COVID-19 outbreak. The forthcoming reduction caused by Sulfuric Acid Today • Spring/Summer 2020
Zhongtiaoshan Nonferrous’ maintenance is unexpected to be sufficient to substantially improve fundamentals or give a boost to copper prices which are now dictated by developments on the epidemic and policymakers’ action against the economic impact of the virus.
CSCEC pens contract to build acid plant in Egypt
CAIRO—A Chinese industrial and construction consortium including China State Construction Engineering Corporation (CSCEC) has won an $848 million contract to build and operate a large phosphoric and sulfuric acid factory in Egypt. Located near the Abu Tartour phosphate mine in the southwestern New Valley Governorate, the plant will boost Egypt’s standing as a major producer of the acids, which are used in fertilizers, food and beverage manufacture, electronics, and other products. Commissioned by Egypt’s state-owned Phosphate Misr Company, the plant will have the capacity to produce 500,000 tons of phosphoric acid and 1.6 million tons of sulfuric acid a year. The Abu Tartour Plateau has a reserve of more than 5 billion tons of phosphate rock. CSCEC said the deal “will effectively drive the Chinese phosphorous chemical industry and related Chinese equipment to go global.” Phosphate production has helped Egypt industrialize. According to Phosphate Misr Chairman Khaled El Ghazaly, “in just over three decades Egypt has managed to transform itself from a small phosphate ore producer to one of the world’s largest producers with a production capacity of 10 million tons per year.” For more information, please visit www. phosphatemisr.com.
Capstone could become world’s fourth-largest cobalt producer
VANCOUVER—Canada’s Capstone Mining has found that its Santo Domingo copperiron-gold joint venture project in Chile has the potential to produce battery-grade cobalt sulfate at a large-scale and low-cost. “If Santo Domingo was in operation today, refined production of 4,700 tonnes of cobalt per year would make Capstone the fourth largest battery-grade cobalt producer outside of China, and the largest in the Americas,” the company’s president and chief executive, Darren Pylot, said. The mine, in which Korea Resources has a 30 percent interest, would also be one of the lowest cost producers of the battery metal, opening Chile’s vast potential to becoming a key player in the cobalt sector, Capstone Mining said. For financial flexibility, the Vancouverbased miner has structured the cobalt recovery option as a delayed investment decision, timed to begin roughly two years after construction begins on the copper-iron-gold Sulfuric Acid Today • Spring/Summer 2020
concentrator. When and if a strategic partner is found, Capstone Mining could start producing cobalt at an earlier date, it said. “Our concept for cobalt recovery in the 2020 PEA opportunity is based on its association with pyrite, which is preferentially concentrated in the flotation process at the copper cleaners/scavengers and then further upgraded to a 0.7 percent cobalt concentrate,” said Albert Garcia, vice president of projects. “Overall, recoveries for cobalt will be approximately 78 percent, with additional benefits in the form of increased copper recovery, sulfuric acid production and energy generation.” Santo Domingo’s current base case economics don’t include the capital to build cobalt processing facilities or any of the revenues from the metal recovery. Construction at the project, located 50 km southwest of Codelco’s El Salvador copper mine, is expected to start later this year. Over its almost 18-year mine life, Santo Domingo is slated to produce an average of 134-million pounds a year of copper, 4.2-million tonnes a year of iron concentrates and 17,000 annual ounces of gold. Capstone currently has two producing copper mines—Pinto Valley in Arizona, US, and Cozamin in Mexico. For more information, please visit www. capstonemining.com.
WASTE HEAT RECOVERY BOILERS SUPERHEATERS ECONOMIZERS
Zijin to invest $800 million in Serbian mining sector in 2020
FUJIAN Province, China—Zijin aims to launch a project to expand the Veliki Krivlj and Majdanpek opencast mines and launch an investment aimed at opening a Cerovo 2 copper and gold mine this year. The Chinese group intends to begin preparations to launch Borska Reka at the Jama underground mine, which is estimated to contain reserves of nearly 4 million tonnes of copper, 130 tonnes of gold, and over 1,000 tonnes of silver. Moreover, Zijin plans to build a new sulfuric acid plant and a new electrolysis plant at the RTB Bor copper extraction and smelting complex and begin work on opening the Timok-copper-gold project’s upper Cukaru Peki mine in Serbia. The Timok copper and gold project located in eastern Serbia consists of the upper and lower Cukaru Peki zones. Zijin owns 100 percent of the upper Cukaru Peki zone plus a 60.4 percent stake in the lower Cukaru Peki zone, while the American Freeport McMoran owns the remainder. In November, Zijin signed an agreement to buy copper and gold at Freeport McMoran in Serbia for up to $ 390 million. Zijin also has a majority ownership in RTB Bor. The Chinese group injected $ 350 million into RTB Bor’s capital in December 2018 and intends to invest a total of $1.26 billion in improving its manufacturing operations, opening new mines and increasing efficiency. For more information, please visit www. zijinmining.com. q
Op�mus delivered its rst sulfuric acid plant waste heat recovery system in 1996. Across the power and process industries, we’ve produced more heat recovery boilers, HRSGs, superheaters, and economizers than any ac�ve company in the USA. Op�mus and its Chanute Manufacturing plant have a long‐standing rep‐ uta�on for high‐quality workmanship and on‐�me performance. Cus‐ tomers trust our unique manufacturing exper�se and have condence in our quality control and comprehensive project execu�on.
50 years of manufacturing experience 99% life�me on‐�me delivery performance 20 years experience in Sulfuric Acid waste heat recovery equipment
Ph: 918‐491‐9191 www.op�mus‐tulsa.com Email: info@op�mus‐tulsa.com
PAGE 5
Department
Industry Insights
Cover Story
Simplot ups its game at Wyoming acid plant By: April Smith, Editor, Sulfuric Acid Today
Delivery of cold intermediate heat exchanger designed by NORAM.
J.R. Simplot recently completed a major upgrade of its 35-year old sulfuric acid plant in Rock Springs, WY. The 1985 Lurgi plant now sports a new converter among other equipment replacements. Simplot produces high-quality phosphate fertilizer. The company’s Rock Springs site sources its production materials, phosphate and sulfur, from the local region. Phosphate mined from Simplot’s Vernal, Utah mining facility is transported 96 miles via a 10-in diameter slurry line to Rock Springs. Sulfur from sour gas sources arrives by truck and is delivered quickly enough to remain molten. The plant gets additional sulfur by rail. Simplot has built a reputation as one of the most cost-competitive producers of phosphate fertilizers in the western United States. The Rock Springs site operates Sulfuric Acid Today • Spring/Summer 2020
two sulfuric acid plants. The first, and the focus of the upgrade project, is also the largest—a Lurgi model with 2,100 STPD production capacity. The second is a 1,500 STPD Monsanto model built in 1995. The site produces five products: phosphoric acid, super phosphoric acid, MAP, fluorosilicic acid, and 40 Rock™. Simplot’s new homogenous ammonium phosphate product, 40 Rock™ contains a unique combination of sulfate sulfur and zinc sulfate for immediate crop availability and plant uptake. And with the recent addition of a 600 STPD ammonia plant, the Rock Springs facility makes anhydrous ammonia that supplies its own fertilizer production needs as well as its sister plant in Pocatello, Idaho.
A project in two phases
Though the key replacement item
was the converter, the full scope of the project included replacements for the cold intermediate heat exchanger, economizer 1, and ducts connecting all the equipment, with dampers. A new distributed control system was also added. The large-scale project required long-range planning and implementation over two construction phases. Planning began with an initial replacement study in 2014 and an updated version in 2016. Phase one, completed in May 2017, consisted of shifting economizer 3 and replacing some ductwork to accommodate the larger converter. The second and more extensive phase officially commenced in August of 2018, consisting of the fabrication, erection, and installation of the converter and the remaining equipment. The project was complete by June 2019.
Converter
The principle focus of the upgrade was a new converter to replace the original 31.5-foot diameter unit that was at the end of its useful life. The original equipment had a center support core that took up significant cross-sectional area and was designed for a much lower gas flow rate than was required currently. The new design needed to handle the higher velocities required for the present operation. The design also had to have sufficient catalyst capacity to facilitate the required conversion for the site’s elevation. At about 6,700 feet above sea level, the low atmospheric pressure created an extra challenge maintaining desired gas flow with more catalyst and achieving the required SO2 conversion. Simplot chose NORAM Engineering & Constructors Ltd. for its converter PAGE 7
Cover Story
New equipment (in white shading) includes converter, ducting, and cold intermediate heat exchanger.
design and long history working at Rock Springs as well as other Simplot locations. “NORAM knows this site and they’ve been consulting for us for years, said Rob Young, Simplot’s project manager. The NORAM converter with welded stainless steel posts and catenary plate design eliminates the need for a central core. This feature, combined with a larger 36-foot diameter, created an important 31 percent increase in crosssectional area from the original unit. The increased cross-sectional area affords more space for catalyst thus improving gas pressure drop and optimizing conversion. The design also employed a heat-up duct that adds heat in the lower passes to reduce startup time. The fully welded design allowed the converter to be shop fabricated in sections and shipped to the site. This feature reduced site construction time significantly while producing a high quality final product. But before committing to these specifications, the team had to settle an important question—how to fit the larger unit within the limited plant perimeter.
Rob Young, project manager, Simplot Phosphates LLC.
PAGE 8
Assembling converter on site, CMW maneuvered small crane within tight quarters.
“The plant layout is such that the converter is right in the middle, and access is extremely limited,” said Young. Although significantly lighter than the existing converter, the new unit would be too heavy to risk lifting in one piece into a very small space. The potential for strong winds delaying the lift introduced a schedule risk, so the team decided to relocate economizer 3, by about 15 feet, to make room. This would create a workspace large enough to erect the converter and then slide it into position. “We dubbed this ‘the Morrison shift,’” said Young, “named for Brad Morrison from NORAM who came up with the idea.” Although Young was quick to explain that there were other legitimate claims on the idea, it was “the Morrison shift” moniker that stuck. “But regardless,” Young said, “it was a great idea.” So the Morrison shift became the
Built on rails, the completed converter was slid 50 feet into place.
New NORAM converter provides 31 percent more cross-sectional area than original unit.
central part of the project’s first phase, setting the stage for the rest of the upgrade during phase two.
Build, lift, and slide
Erecting the converter within tight quarters of the construction area called for agility. Several contractors reviewing the project declared it “impossible,” Young said, because there wasn’t enough space to maneuver a crane. But the fabricator, Central Maintenance and Welding (CMW), had experience operating in such conditions. “CMW was the only contractor who said they could use a small crane for the job,” Young said. So CMW fabricated each of the seven converter layers in four sections, delivered them via truck through the narrow alleyways to the newly created workspace, and assembled the vessel by a small crane. Once the unit was built, it was slid just
NORAM-designed cold intermediate heat exchanger with hot sweep.
Economizer 3 in original location (left) before “the Morrison shift” made room for converter.
Sulfuric Acid Today • Spring/Summer 2020
Cover Story
Cold intermediate heat exchanger in Axton’s Vancouver fabrication shop.
Ducting destined for Rock Springs, WY, leaves CMW’s fabrication facility in Florida.
a short distance into position. CMW played a central role in the plant upgrade both as the general contractor and as chief fabricator. Other than the converter, the contractor fabricated the large amount of ductwork connecting the new equipment. As for catalyst, some was screened and reused, but most was replaced with MECS® GEAR® series catalyst. Installed in pass one was GR330, in passes two and three was GR310, and the fourth
pass was installed with SCX-2000 cesium catalyst. VIP International, who loaded the catalyst beds, also helped the team finalize the converter design by suggesting more efficient manways. “Rather than have one manway as with the original converter, VIP recommended two, one for equipment going in and out, and the other for personnel,” Young said.
Heat exchanger & economizer
The new cold intermediate heat exchanger is based on NORAM’s radial flow design with a hot sweep to reduce condensation. Simplot’s sister plant has been successfully operating with a similar unit for over 15 years. The technology
Much of the original catalyst was replaced with MECS® GEAR® series installed by VIP International.
Connecting pieces of ducting at Simplot’s Wyoming plant.
improvement also allowed for a smaller footprint, more efficient operation, and less pressure drop. The unit was fabricated by Axton just outside of Vancouver, British Columbia. The team also replaced economizer 1, responsible for cooling gas between the second and third converter beds. The new catalyst loading changed the heat loads on some of the equipment and economizer 1 needed to be replaced as a result. The new unit was engineered, fabricated, and supplied by Optimus.
Ducting
A significant aspect of the upgrade was replacing 17 gas ducting segments, eight dampers, and 13 expansion joints. Every duct connection run to the converter was replaced with a stainless steel duct designed and supplied by NORAM. The contractor completed a 3-D laser scan to help identify tie-point locations and ensure there are no major changes relative to the original ducting drawings. “There is as much art as there is science in designing good-fitting replacement ducting for older acid plants,” Young said. “NORAM’s ducts connected smoothly and precisely to the existing equipment.”
Challenges
New economizer, designed and fabricated by Optimus of Tulsa, Oklahoma.
Sulfuric Acid Today • Spring/Summer 2020
Optimus economizer being lifted into place.
Despite careful advanced planning, the inevitable curveball attempted to knock the project off course. The existing distributed control system (DCS) could not accommodate the extra temperature probes for the converter, so a new DCS was added to the to-do list.
Stuffing tubes in NORAM designed and supplied cold intermediate heat exchanger by Axton, NORAM’s fabrication shop in Vancouver.
Since it was not part of the original bidding, the DCS and associated electrical work was bid under a separate contract and run as a separate project concurrently with the main upgrade work. This meant greater coordination between the two workflows. Fortunately, CMW was able to coordinate its efforts and complete its work in enough time to enable start-up and testing of the DCS within the allotted downtime. “CMW was able to hit the completion date for assembly right on time,” Young said.
Measuring success
Despite the various snags, the work was completed within 32 days, just two days over the planned outage window. Add to that the safe execution of the work with no lost-time injuries, and the team was able to check off its most important goals. “There was a tremendous amount of work packed into the short outage window and it was all completed safely and on time,” Young said. “After a smooth startup, the chief objectives of the project were met,” Young added. q PAGE 9
Feature
market outlook
The China challenge
By: Fiona Boyd and Freda Gordon, Directors of Acuity Commodities
In our last article in the Fall/ Winter 2019 issue of Sulfuric Acid Today, we noted that China would be the wild card for 2020. This was before the onset of COVID19, first reported in the last days of 2019, added further complexity to the market. Our view that China would be the wild card this year was driven by its shift to a net exporter of sulfuric acid in 2019 compared with its usual role of being a net importer and critical in balancing the Asian market. In 2019, China exported close to 2.2m t of sulfuric acid, close to a 70 percent increase from the volume exported in 2018. Meanwhile, it imported around 530,000t in 2019, or close to a 90 percent decrease from 2018. The around 400,000t reduction in China’s imports and the close to 900,000t increase in exports shifted China’s sulfuric acid balance by around 1.3m t in 2019. As we discussed in our last article, this shift in China was a significant contributor to a decline in sulfuric acid prices globally in 2019 compared with 2018. It put notable pressure on Japan and South Korea, which are the major sulfuric acid export countries in Asia. As a result, spot export pricing out of these two countries moved from a high of $79/t freight on board (FOB) in January 2019 to $5/t FOB by the end of the year. We should note, however, that in Acuity’s view, sulfuric acid pricing seen towards the end of 2018, which set the tone for 2019, was due to an unforeseen and perhaps overinflated surge in pricing in 2H 2018. In addition, in 2019 prices were negatively impacted by market sentiment due to a series of unexpected events, including geopolitical tension. And while stability was found by the end of 2019, albeit at lower prices, a
PAGE 10
significant market disruptor was on the horizon. As 2020 commenced, news of COVID-19 developing in Wuhan city, Hubei province, China, began to emerge. As the virus began to spread, its impact on China’s industrial activities was significant with the flow of many commodities, raw materials, and other goods hampered and many industrial sites not able to operate due to this as well as lack of labor amid widespread quarantines. One of the impacts on the sulfuric acid market thus far has been a decrease in domestic demand for sulfuric acid. This has been occurring while sulfuric acid production from China’s base metal, mainly copper, smelters does not appear to have been as impacted as the consumption side. However, we note that since the Hubei province was in a lockdown in early February, many of the smelters in China have been running at reduced rates. This means that Chinese producers of by-product smelter acid, which is often referred to as fatal due to its necessity to move, have had to look for alternative markets. In addition, acid suppliers in South Korea and Japan also had to look for alternative markets with China’s import requirement even lower than seen in 2019. As such, by around midFebruary 2020, spot sulfuric acid export prices in Asia reached double digit negative values for the first time since February 2017. At the time of writing, one key uncertainty that will influence the coming months is the state of China’s base metals smelting industry. The key driver for the increase in sulfuric acid exports last year from China was the ramp up in smelting capacity in the country, which resulted in the need to export to keep the market balanced. Acuity estimates that in 2019, China’s sulfuric acid production from smelting grew by around
3m t, to reach close to 34m t. Meanwhile, in our early 2020 supply and demand forecast, before the intensity of COVID-19 impact was recognized, we had forecast an additional 500,000t of production from smelting in China this year to be followed by additional growth through 2023. The 2019 growth was from the start up of new smelters by Chinalco, Guangxi, Yunnan, and Zihjin, which we expected to add additional supply in 2020. The question now, however, is whether China’s access to copper concentrates could be notably disrupted, therefore slowing the intake and constraining by-product sulfuric acid production accordingly. This could help offset some of the lower consumption and reduce the need to export. There are indications that this could occur with spot copper treatment and refining charges (TC/RCs) increasing due to increased availability stemming from COVID-19 outbreak. TC/RCs are low when concentrate availability is tight as a way to attract concentrate throughput for smelters and increase when there is greater availability. While it remains that the magnitude and duration of COVID-19 is highly uncertain, it is certainly not contributing to a bullish view for most commodities for the balance of the year. The evolving situation is also occurring while both phosphate and sulfur prices remain at low levels on a historical basis, further contributing to a bearish market view. The impact of coronavirus on China, the world’s largest sulfur importer, is another large unknown. Previously, much of China’s phosphate fertilizer production capacity was cut due to the virus. This was notable in Hubei, which is home to around 35% of China’s capacity in terms of phosphoric acid. The impact of this was a slight uptick in phosphate pricing due to reduced output in China, further supported by previous curtailments by producers in other regions due to weak market conditions. This resulted in a slight uplift in phosphate pricing and while bearish from a sulfur consumption perspective, the sulfur market has not seen a dramatic decline in sentiment or prices. Trade is indeed thin, partly down to the reduced import needs from China at present but more importantly a limited number of spot cargoes on offer.
Fiona Boyd, Acuity Commodities
Freda Gordon, Acuity Commodities
As time progresses, however, it is reasonable to assume that the longer liquidity in China remains limited, the more pressure to move tonnes will mount. One bullish view is that China could soon start to boost production in phosphate fertilizers at the request of the government as a way to ensure domestic availability for the upcoming spring application season. This is resulting in a sustained wait-and-see mode among market participants. Price ideas and movement will soon be tested as suppliers begin to discuss contract pricing for 2Q, which will be the first discussions since the significance of COVID-19 has been realized. Acuity recently analyzed 40 years of price history for the Tampa molten sulfur quarterly contract price, a key benchmark in North America. It reflected that the current 1Q Tampa price of $36/lt DEL is the second lowest going back 40 years. The record low in the last 40 years was $0/lt DEL, seen in 1Q09. Prior to that, the previous low was in 1Q02 at $40.50/lt DEL with an annual average for 2002 of $41/ lt DEL. The accompanying graph reflects the annual average for the Tampa molten sulfur quarterly contract price going back to 1980. It is interesting to note the relative stability of pricing prior to the run up in 2008 and collapse in 2009, with more price volatility seen since. At the time of writing, we were not expecting to see a decline in the second quarter Tampa price due to the current balanced market, limited price movement in 1Q despite the uncertainties in China, and slightly improved conditions in the phosphate fertilizer market. To call 2019 a year of geopolitical turbulence is no exaggeration when we consider factors such as Britain officially leaving the European Union and the US-China trade war. Various geopolitical
issues appeared to be carrying over into 2020 and impacting commodities sentiment accordingly. This included firmer crude oil prices due to escalating tension in the Middle East. This saw crude prices hitting the highest levels since May 2019 in the early days of 2020. This has now been reversed, however, by reduced crude oil consumption in China having a more notable impact. As we look to the balance of the year, the outlook firmly lies on resolution of COVID-19. At the time of writing, it was clear that the Chinese government was determined to restart most companies and plants as soon as possible, which is a positive not only to the global economy but also to the demand for sulfur and sulfuric acid. However, as the virus continued to spread across the world at press time, even if all industries resumed in China within late 1Q/ early 2Q, there were no positive indicators the situation was subsiding. Unfortunately, this is leaving many commodity markets in a state of flux, including sulfur and sulfuric acid. It appears that for now, the only thing that is certain is continued uncertainty. As we have noted before, all markets respond to supply and demand fundamentals and with China on the sidelines in many respects, it is too hard to call the impact on these fundamentals. This reinforces the notion if China sneezes, the world catches a cold. Acuity Commodities provides insight into the sulfur and sulfuric acid markets through price assessments, data, and supporting analysis. Offerings include weekly reports on the global sulfur and sulfuric acid markets and a biweekly report focusing on North America as well as bespoke consulting work. Please visit www.acuitycommodities.com for detailed information. q
Sulfuric Acid Today • Spring/Summer 2020
Feature
Improved tank vent emission control By: Graeme Cousland, Director, Begg Cousland
Product storage tanks for holding sulfuric acid or oleum are an important part of a sulfuric acid plant’s equipment. Without an effective air pollution control system, the venting of these tanks or the loading and unloading of tankers and railcars often results in a white haze plume. Common practice has been a 3-stage arrangement: a hydrolysis section, where the air or SO3 gas is contacted with a counter-current H2SO4 spray inside a vertical or horizontal pipe; then a mist eliminator to collect the acid mist formed by the hydrolysis reaction; and finally a discharge fan. In 1992 I.C.I., the major chemical company in the U.K. at that time, patented a ‘Gas Moving Device.’ It was initially intended as a de-dusting scrubber, for I.C.I.’s own limestone quarries, and was often referred to as the ‘Spinning Mop.’ It had excellent efficiency in removing solids larger than two microns in diameter; but what made it even more interesting was the concept of using a brush as an impeller inside a fan volute and then spraying it to make it work as a wet scrubber. Begg Cousland initially signed a license agreement for the technology in 1988 and re-christened it ‘Becoflex.’ Numerous niche applications were found where it could be used either in its basic BF model form, or by combining it with second stage equipment, such as a fiber bed mist eliminator in a BFCF model. The Becoflex Rotary Brush Scrubber uses a brush rotor in place of an impeller, but with a standard fan motor. The brush can generate up to 110mm H2O (almost 4.5
inches W.G.) of fan static pressure, which overcomes the mist eliminator pressure loss and has enough suction remaining to draw the vent gas into the unit and out of the stack. Inside the volute the brush is sprayed with water or H2SO4 and the spinning brush fibers make an intensive mixing effect of liquid and gas, thereby optimizing the hydrolysis of the SO3. So, the volute section is a dynamic combination of fan and gas contactor. The liquid is thrown off the brush fibers by centrifugal action and onto the inside of the volute casing and from there it flows along a short connector duct to the mist eliminator vessel. The liquid then falls down to the sump of the vessel, while the clean gas moves upward toward the mist eliminator. The liquid can be recirculated from the sump or from a separate, connected pump tank.
Schematic of a basic oleum vent unit.
Schematic of a basic Becoflex BF model.
A Becoflex brush rotor. PAGE 12
Schematic of a Becoflex BFCF model.
Some systems use a once-through arrangement and have a header tank to feed fresh acid to the volute’s spray nozzle. H2SO4 mist is generated in the volute and these particles would cause a very visible white plume if emitted directly to the atmosphere. A Brownian diffusion type mist eliminator, using a Begg Cousland TGW15 or B14W fiber bed will remove these small and sub-micron aerosols to leave an optically clear stack exit. In an old-style system, a lot of the solid materials in the gas coming from the tank could pass through the simple pipe wetting arrangement, and reach the mist eliminator, where they would increasingly cause plugging, higher pressure loss, and a loss of system suction. With a Becoflex BFCF unit, the solid matter would be immediately contacted by the wetted brush fibers during rotation and would be thrown off by centrifugal action along with the liquid. This means that the mist eliminator is effectively protected from blockage. (Note: Even with all purely solids removal, there has never been a blockage of the system). The available materials of the brush fibers are polypropylene or P.V.D.F., and brush life is a minimum of 5 years. The materials of the volute and vessel can be metal or synthetic, typically PP/ FRP. Depending on the conditions, the brush rotor metal can be stainless steel or Hastelloy. The Becoflex units are available in 11 sizes, with air flow range from a few hundred m3/hr or acfm up to a maximum of 25,000 m3/hr (+/- 14,700 cfm) in one volute. Larger flow duties are handled by multiple brush volutes in parallel linked to a single downstream vessel. As a final word about the benefits of a Becoflex BFCF tank vent system, it does not take up much space and can even be sited on top of a tank (see photo from 2001) to save additional equipment footprint. The Becoflex BFCF system was first used in
Becoflex BFCF40 unit operating since 2001.
Becoflex BFCF40 unit operating since 2006.
this tank vent duty almost 20 years ago. The unit still operates well and needs minimum maintenance or replacement parts. Becoflex has also been very successful in handling vent and fugitive emission gas in the phosphate fertilizer industry, safely treating gas containing phosphate rock dust, and removing phosphoric acid and fluorosilisic acid fumes from the environs of tanker loading and washing stations. For more information, visit www.beggcousland.com. q Sulfuric Acid Today • Spring/Summer 2020
Feature
Sulfur gun advancements In production of sulfuric acid from molten sulfur, it is critical that the sulfur is atomized into droplets so that combustion occurs efficiently. The spray nozzle converts bulk sulfur into a predictable droplet size distribution, spray angle, and coverage. The most widely used nozzle in sulfuric acid production today is the BA WhirlJet® nozzle. These nozzles provide superior performance during normal operation, but when flow is decreased or turned off, the nozzles may plug. This happens because the nozzles protrude beyond the steam jacket of the sulfur gun. Without the cooling provided by the steam jacket, the sulfur flowing inside the nozzle heats up beyond the normal working temperature. This causes the sulfur viscosity to increase and plugging may occur. Operators have been compensating for this by purging the nozzles or removing the guns at the end of operation. However, if one of these actions doesn’t occur quite quickly, pluggage is likely. Flexibility in production rates is required to optimize sulfuric acid production. Sulfur guns are either turned on and off, or flow rate is increased or decreased. To meet this requirement and minimize pluggage, a new sulfur nozzle and gun have been introduced. The CBA SulfurJet™ nozzle has the same superior performance as the BA WhirlJet nozzle. The CBA SulfurJet gun features a steam jacket that fully protects the nozzle to minimize or eliminate plugging. As sulfur passes through the CBA SulfurJet nozzle, sulfur temperature is maintained in the optimal range as production rates change.
Fig. 1
PAGE 14
Fig. 3
In production of sulfuric acid from molten sulfur, it is critical that the sulfur is atomized into droplets so that combustion occurs efficiently. (3,847 lbs/hr) sulfur at 5 psig ΔP (0.35 bar). The feed sulfur temperature was set at 284°F (140°C) and steam in the steam jacket pipe was at 293°F (145°C) and 60 psig (4.1 bar). At full flow conditions for both spray nozzles, the sulfur temperature was maintained until it exited the spray nozzles. The temperature change in the BA WhirlJet nozzle was validated
CBA SulfurJet nozzle and CBA SulfurJet gun validation research
Computational Fluid Dynamics (CFD) was used to model heat transfer in a sulfur gun with BA WhirlJet nozzles and a gun equipped with CBA SulfurJet nozzles. A full flow rate condition of 9,410 kg/hr (20,745 lbs/hr) sulfur at 150 psig ΔP (10 bar) was compared to a reduced flow condition of 1,745 kg/hr
By: Chuck Munro, Refinery Application Specialist, Spraying Systems Co.
Fig. 2
when the reduced flow conditions were used. Fig. 1 shows the BA WhirlJet nozzle at the reduced flow conditions. The sulfur polymerizes inside the nozzle as the temperature rises above 305.6°F (152°C) and starts to form a skin. Over time, the skin grows thicker and reaches the point where the sulfur can no longer pass through the nozzle. The CBA SulfurJet nozzle
is shown in Fig. 2. At the same reduced flow condition, the sulfur temperature remains at 289.4°F (143°C) as it passes through the nozzle. Polymerization does not occur. Due to the hydraulic atomization design, the pressure to the gun is decreased as the flow rate is reduced. As a result, velocity through the internal cavity is decreased. Velocity for the BA
WhirlJet nozzle at the exit is reduced from approximately 32 m/s (105 ft/sec) at full flow rate to approximately 8 m/s (26.2 ft/ sec) at reduced flow rate as shown in Fig. 3. Since the fluid moves more slowly through the gun, the temperature near the walls of the sulfur cavity increases to 635°F (335°C). This causes the sulfur to polymerize at 318.2°F (159°C) and eventually build a skin inside the nozzle. The velocity decrease in the CBA SulfurJet has a smaller impact temperature of 442.4°F (228°C) and pluggage is avoided.
Summary
The new CBA SulfurJet nozzle and CBA SulfurJet gun deliver the flexible performance required by producers. The new nozzle provides superior atomization of bulk sulfur so producers can achieve the same or better performance than the BA WhirlJet spray nozzles currently in use. In addition, the new gun design allows production rates to be adjusted with reduced risk of pluggage. Producers will be able to maximize production time, reduce maintenance time, and extend gun life. Chuck Munro has more than 20 years of experience in spray technology with Spraying Systems Co. He is a specialist in the petrochemical and chemical industries and is active in several industry committees. For more information, visit www.spray.com. q
Sulfuric Acid Today • Spring/Summer 2020
VK sulfuric acid catalysts
The profitable way to sulfuric acid Keep conversion rates high and production costs low with the VK range of sulfuric acid catalysts. Partner with Topsoe, as we are the leading supplier of sulfuric acid catalysts, and get holistic solutions for your plant. Our experts assess and deliver tailor-made solutions, maximizing your performance.
www.topsoe.com
Learn more www.topsoe.com/processes/sulfuric-acid
Feature
lessons learned: Case histories from the sulfuric acid industry
Consequences of a failed mist eliminator drain By: Steve A. Ziebold, Doug E. Azwell, and Evan Uchaker, DuPont Clean Technologies, MECS® Sulfuric Acid & Environmental Technologies
In sulfuric acid absorbing towers, a hanging mist eliminator has traditionally used a drain leg or seal leg directed to distributor troughs or a drain leg/seal cup combination to allow collected mist to drain by gravity out of the element into the process, as shown schematically in Fig. 1. Draining liquid travels from a low pressure point on the gas discharge side of the element to a higher pressure point upstream of the element. The drain leg or drain leg/ seal cup fails when blocked or plugged, which prevents liquid from draining out of the mist eliminator. The drain leg or drain leg/seal cup also fails when blown—when a liquid seal is lost resulting in gas flowing up through the drain leg directly, bypassing the mist eliminator. At a plant in South America, a client was having problems with high-drip acid accumulation downstream after their IPAT hanging mist eliminators. Upon entering the tower and inspecting the tubesheet from the top side, one side wall area had excessive sulfate and there was a considerable amount of wet sulfate on the tubesheet. One element was found to have free standing liquid in the bottom as shown in Fig. 2. It was apparent acid had backed up and was trapped in the element since collected liquid was not freely flowing into the center drain coupling. On subsequent inspection under the element, the seal cup was found to be plugged solid with sulfate. When a hanging element drain is blocked, collected liquid in the bottom of the element rises to the top of the internal gas veil and tries to drain back through the fiberbed against the gas flow. The collecting fibers become over-saturated and gas flowing through the fiberbed creates bubbles at the liquid level/fiberbed interface which in turn generates acid particles by bubble shatter. Acid particles then travel downstream carried by the gas exiting the mist eliminators, exposing downstream equipment to drip acid resulting in corrosion and maintenance issues. At a plant location in the United States, a client was having spotted stick tests and drip acid accumulation downstream of their
Fig. 1: Vessel seal leg arrangements. PAGE 16
hanging IPAT mist eliminators. After plant shutdown and tower inspection, the root cause was determined to be a separated drain leg threaded fitting that became loose and detached by process vibration. The client was able to re-attach their threaded drain leg fitting and the downstream stick tests cleared up and drip acid was eliminated. For element drain legs, if threaded fittings are used, it is a prudent practice to tac weld threads to prevent separation during process service. Like a blocked element drain, a blown element drain is also an operating condition that, if left unchecked, will have serious maintenance consequences. Gas bypassing through a blown element drain leg prevents liquid collecting in the bottom of the element from draining. A large amount of re-entrainment is formed by gas vertically discharging through the bottom element drain coupling and consequently shearing collected liquid and regenerating acid particles (Fig. 3). Acid particles are then carried downstream by the gas exiting the mist eliminators, exposing downstream equipment to drip acid and resulting in corrosion and maintenance. A blown seal leg two inches in diameter and three feet long exposed to a 250 mm WC element pressure differential will bypass about 460 ft3 min-1 of dirty gas with an upward gas velocity leaving the seal leg at about 350 ft s-1. At this velocity there is plenty of gas shear force to atomize acid accumulated in the bottom of the element into small particles that re-entrain and discharge from the element resulting in corrosion of downstream equipment.
Fig. 2: Free standing acid at the bottom of an IPAT tubesheet element.
Fig. 3: Schematic representation of a blown seal leg.
New proven alternative to traditional hanging element drain legs
The patented MECS® AutoDrain™ (AD) option for hanging style Brink® mist eliminators effectively drains acid without the use of expensive seal legs/seal cups or complex seal leg piping systems (Fig. 4) routed to MECS® UniFlo® distributors. AD eliminates the hazard of working in acid resistant apparel required to attach drain legs to hanging elements below the tube sheet, which is a very dangerous work area. When elements are removed from a tower, this same hazardous work must be performed to detach drain legs before they can be lifted out, and AD eliminates this hazard as well. AD eliminates element seal legs directly routed to trough distributors or seal leg/seal cup assemblies, which are the more frequent maintenance spots in the absorbing tower and one of the more
difficult areas to troubleshoot. Also, when maintenance is required on tower acid distributors, the hanging drain legs (pipes) from the mist eliminators are a significant obstruction to anyone working in acid resistant apparel, which can result in falls and injury. AD eliminates this safety hazard by removing all the hanging drain legs or seal legs/seal cups, providing significantly fewer obstructions under the mist eliminators resulting in easier and safer maintenance on tower components. In fact, when observed through viewports during operation, the inside plate at the bottom of the element with AutoDrain™ will typically be dry, while the bottom plate of a standard element will typically have some accumulated liquid on it. As a result, AutoDrain™ elements have less entrainment and higher efficiency than standard elements. While there have been recent claims of similar devices, these devices are not comparable since they use liquid traps. Liquid traps require liquid height changes to allow collected liquid to drain from the bottom of the mist eliminator when an internal float changes position. The liquid trap is not recommended for sulfuric acid service due to buildup of sulfates on sealing surfaces during operation, leading to premature failure during operation causing re-entrainment. The bottom element plate operates in a fully wetted state and may hold up a larger volume of acid than with standard drain legs. AD does not have this kind of operational concern as the bottom of the element operates bone dry. While the consequences of improper seal leg and seal cup maintenance and operation have been broadcast throughout the industry, they continue to be a reoccurring problem. It is critical that mist eliminator users stay up to date on maintenance and inspections to mitigate any potential issues so that their mist eliminators achieve satisfactory performance and long service life. For more information, visit http:// www.cleantechnologies.dupont.com. q
Fig. 4: On left, a typical seal leg/cup installation and, on right, MECS® AutoDrain™ setup. Sulfuric Acid Today • Spring/Summer 2020
Acid Piping Technology — The world leader in reliable and cost effective products for the sulfuric acid industry since 1991
MONDI™ PIPINg SySTeMS APT HIgH PerfOrMANCe CerAMICS
MONDI™ Piping Systems – Special ductile iron alloy for 93-99% sulfuric acid at temperatures up to 300 degrees F (149 degrees C) and oleum. Unique alloy and heavy wall construction provide 30-plus years of reliable service. APT step ring gaskets provide leak-free seal in hot acid. • Proven performance in acid plants since 1983 for recirculation and transfer systems • Tough sulfate film formed results in low corrosion rates • Good tolerance to weaker acid excursions due to process upset or shutdown conditions • Industry standard used in over 800 acid systems worldwide including World Class 4500+ ton per day plants • APT maintains large inventory of pipe and fittings for routine and emergency requirements Valves & Instrumentation – Valves are gate, globe, check, plug, ball and butterfly in iron, steel, bronze, stainless steels, alloy or lined with PTFE, PFA, and FEP. Valves are supplied in class 125 psi through 2500 psi. APT has a complete automation facility for valve actuation to supply complete automated package. Instrumentation products include thermocouples, RTD, thermowells, orifice plates, pressure and temperature gauges.
APT High Performance Ceramics – High quality products which meet ASTM C-279 chemical porcelain. Products have excellent chemical resistance, high mechanical strength and low porosity. • Tower packing saddle sizes in 3”, 2”, 1 1/2”, 1”, 3/4”, 1/2” and #1, #2. #3, Super Saddles • Cross Partition Rings, Grid Blocks and Ceramic Balls • APT maintains large inventory of saddles and supports for routine and emergency requirements ASC Acid Plant Valves --- Have been supplied to acid plants for gas duct applications since 1993. These valves are used for many applications within the plant. There valves can have manual gear operators or actuators. • Butterfly valves (BV – metal step 1 percent leakage) for flow control around towers, equipment and heat exchangers • Powercam® BV valves (ANSI Class IV – 0.01 percent leakage) for preheater isolation • Flex-Wedge valves for blower isolation • Refractory BV and Jug valve used on boiler by-pass for flow control
Acid PiPing Technology Acid Piping Technology • 2890 Arnold Tenbrook Road • Arnold, Missouri 63010 USA Telephone: (636) 296-4668 • Fax: (636) 296-1824 • Email: info@acidpiping.com • Website: www.acidpiping.com
Feature
Weir Minerals launches three new Lewis® pumps in major product-line expansion ST. LOUIS – In a significant advancement in its industry-leading product line, Weir Minerals would like to announce three new additions to its Lewis® range of pumps and valves for the sulfur, sulfuric, and phosphoric acid industries. The release of the Lewis® VL Axial Pump, Lewis® Horizontal Process Pump, and Lewis® Vertical High Pressure Molten Salt Pump marks a new chapter in the brand’s proud history of innovative product and material engineering.
Lewis® VL Axial Pump
The three pumps have been designed to maximize wear life in some of the world’s most corrosive industrial applications while simplifying maintenance through their streamlined designs. This has significantly reduced the number of parts compared to previous pumps, without compromising their performance. “Although they’re designed to address different challenges, these three new pumps were guided by the same core design principles: using advances in material technology to achieve increased performance and wear life, while reducing complexity to simplify equipment maintenance and give us the flexibility to deliver more engineered-to-order features that benefit our customers,” said Jerry Ernsky, Lewis® Product Manager, Weir Minerals. “Fundamentally, Weir Minerals is in the business of solving tenacious problems that interfere with our customers’ operations, which is why every step of our product development is guided by
Achieve Legendary Success
Lewis® Horizontal Process Pump
our customers’ key challenges.” First is the new Lewis® Horizontal Process Pump, which combines the longlasting corrosion and wear resistance that Lewmet® alloys are known for with the robust performance, efficiency, and ease of maintenance associated with centrifugal pumps. This single stage, end suction horizontal process pump is the product of years of experience and research, which perfectly complements the existing range of Lewis® vertical acid pumps and valves. “Suitable for a wide variety of chemical processing applications, our new Lewis horizontal process pump offers efficient performance and superior wear resistance to the growing number of acid plants and fertilizer complexes operating around the world. Our engineered-toorder horizontal pumps are customized to support our customers’ goals of reducing plant maintenance and achieving a lower total cost of ownership,” said Ernsky.
CHANGE YOUR WORLD WITH CONCO NitroLance™ liquid nitrogen cleaning service removes the most difficult deposits from heat exchangers completely and without costly waste streams. The NitroLance Cleaning System: • Quicker than hydroblasting or chemical cleaning • Removes deposits where other methods fail • Generates zero secondary waste Conco crews are available 24/7 with a response time and safety record that is second to none. Achieve Legendary Success by putting over 90 years of experience to work for you. Change Your World with Conco.
Sulfur Recovery Unit Before Cleaning with NitroLance
Sulfur Recovery Unit After Cleaning with NitroLance
Conco Services Corp. 1-800-345-3476 www.conco.net
Lewis ® Vertical High Pressure Molten Salt Pump SAT 1/4 V NitroLance 2017.indd 1
PAGE 18
1/30/17 5:26 PM
The new Lewis® VL Axial Pump offers heavy duty construction ideal for use in corrosive, high temperature chemical processing applications, such as evaporator and crystallizer circulation. Its innovative design is highly flexible and can be customized to suit a wide variety of industrial applications, while its low component count makes servicing quicker and easier. The Lewis® Vertical High Pressure Molten Salt Pump has been designed to meet the needs of the burgeoning concentrated solar power (CSP) industry. This multi-stage vertical turbine pump has been specifically designed to handle the multifaceted challenges associated with the extremely high pressures and temperatures associated with pumping molten salt for thermal energy storage. The molten salt pump can be expanded from 3 to 14 stages, has an integrated protective thermal barrier, a non-contracting shaft seal, and a low NPSH first stage. Available with water or air-cooled thrust bearings, Lewis® vertical high-pressure molten salt pumps support heads of up to 701m, temperatures of 593°C, and up to 10.3Mpa pressure. “Our new multi-stage molten salt pump is the first that has been custom designed to meet the unique requirements of the rapidly expanding number of concentrated solar power plants around the world. Lewis pumps have always thrived in the world’s most demanding, high temperature applications and we’re delighted to bring our experience and engineering expertise to this increasingly important source of renewable power,” said Ernsky. All three pumps are constructed with Weir Minerals’ industry-leading Lewmet® alloys, which incorporate highly specialized metallurgy designed to survive in the most corrosive industrial applications involving sulfur, sulfuric, and phosphoric acids. Weir Minerals Lewis Pumps has developed an international reputation in the design and manufacture of pumps and valves in the sulfur, sulfuric acid, and phosphoric acid industries. The new Lewis® VL Axial Pump, Lewis® Horizontal Process Pump, and Lewis® Vertical High Pressure Molten Salt Pump are now available worldwide. For additional information, customers can contact their local Lewis representative or visit www.global. weir/brands/lewis. q Sulfuric Acid Today • Spring/Summer 2020
We are everything sulphur As the recognized world leader for sulphur-related projects, Worley has over 65 years of providing unique total sulphur and sulphuric acid management solutions globally. Worley can provide leading technology, plants, equipment and solutions for all parts of the sulphur chain. We are everything sulphur. ComprimoÂŽ Sulphur, ChemeticsÂŽ Sulphuric Acid, and Advisian Port and Logistics solutions provide world wide focus on site reliability, environmental solutions, plant economics and workforce development.
H2S
Refinery/gas treatment
Tail gas treatment/ scrubbing
Sulphur recovery unit
Sulphuric acid plant
Sulphur handling
Sour water stripping
H2SO4
SO2
Sulphur
SO2 Smelter/power plant SO2 source
The Hague
London
Spent Acid
Chemical/ refineries Phosphoric acid plant
H2SO4
H2PO4
Phosphate based fertilizer
Comprimo Chemetics
Gas cleaning plant
Vancouver
Sulphuric acid regeneration/ concentration
Worley/Advisian
Toronto
advisian.com/comprimo
Calgary
Perth
Los Angeles
Mumbai
worley.com/chemetics
Santiago
Feature
Developing and maintaining a working at heights program
By: Patrick Ferguson, safety coordinator, VIP International Inc.
Construction and industry have come a long way from the times of iron workers working at heights and casually walking along the beams of newly constructed skyscrapers. One can only imagine the scoffs of those workers if they could be shown the equipment and procedures of today’s workplace. Further to that point, one can also imagine their heartache when a coworker was hurt, or worse, due to a fall or falling object. Actually, that it is not hard to imagine even today. Despite revised standards and new technology, workers are still falling at high rates and fatality statistics have actually grown. In 2015, there were 42,400 recordable injuries in the United States alone from workers struck by falling objects or equipment. With so much at stake, what can we do as leaders and professionals in our industry to protect our workers from these hazards? Creating a program is a step in the right direction for smaller companies. While multinational corporations have intricate programs in place, a basic but effective working at heights program can prevent injuries and save lives in a smaller company. It can, however, be intimidating for a leader, unfamiliar with basic working at heights principles, to document and apply the principles to their type of work. When creating a new in-house program, employers need to ensure the program administrator has the knowledge and experience to implement it properly. This administrator could be an experienced employee who takes formal training on the specific subject or a safety professional that attends continuing education courses to ensure retained knowledge on the subject matter. Hiring an experienced consultant to PAGE 20
customize the program to the needs of the company is an expensive but reliable option. Larger corporations with programs in place must revisit their programs frequently. If an incident involving working at heights occurs, one of the first responses may be to review the program and investigate where gaps may have existed for that particular event. This is an important part of the improvement process. However, taking a proactive approach by scheduling reviews of the program can help identify gaps before an event occurs. This will also ensure best practices are being followed and updates to standards are communicated.
ers interact directly and indirectly with that area. Graphics, measurements, drawings, and pictures can be used to assign exposure ratings for each area. These observations must be made over a period of time so that frequencies and durations of tasks can be established. Hazard risk factors should be assigned from highest to lowest priority. Environmental factors such as weather, chemicals, electrical hazards, as well as sharp objects, abrasive surfaces, etc. must always be considered in fall hazard surveys. It is important that a competent or qualified person perform the survey, as it requires a solid understanding of workplace hazards. When changes in the work area
“
As leaders and professionals in industry and construction, it is critical that we strive to set up our teams for success.
”
In order to help the program administrator fully understand what will be needed to develop a working at heights program, the workplace must be examined. American National Standards Institute (ANSI) Z359.2 guidelines state that performing fall hazard surveys will help identify the proper procedures, types of equipment, and training needed to eliminate or control different fall hazards. Some initial observations will be the configuration of the work area and an analysis of how work-
take place, the survey must be revised or rewritten. By following the hierarchy of fall controls, the proper procedures and equipment can be identified for the working at heights program. If the survey reveals that a procedure or piece of equipment can be used to prevent or eliminate a fall exposure, then it should be the first option. Passive fall protection such as fixed barriers or rails can also be put in place to prevent personnel from interacting with fall hazards as well as placing netting or mesh below a
work area to catch falling objects. When options are limited, active fall protection systems (Personal Protective Equipment) can be used. Fall arrest and restraint systems, as well as tool lanyards, are very common in the workplace, but ideally should be used as a last option. All fall protection procedures in a working at heights program should be written in clear and concise language. Procedures should not be limited to application in the work area. Items such as procedures for inspection, use, cleaning, and storage of fall protection equipment, as well as rescue in the event of a fall, must be included in the written program. If changes are made to any parts of the programs, they should be reflected in the written procedures, controlled to avoid confusion with old procedures, and communicated to the affected personnel. Fall protection, falling object prevention, and fall rescue plans are also essential communication tools for affected workers. The next step and possibly the most important in the development of a working at heights program is to establish training elements. ANSI Z490.1 guidelines are a great resource when developing the training portion of a program. While awareness training can contain good content relating to working at heights, it does not suffice for a comprehensive program. A training needs assessment can be performed to guide the administrator in the right direction. A needs assessment will identify necessary items including: training outlines, learning objectives, prerequisite training, training aid requirements, instructor and trainee ratios, evaluations, and minimum per-
Identifying proper fall protection systems is integral to working on temporary elevated work platforms.
formance requirements for trainees. Retraining cycles must be established based on the type of training and any changes made to the program. Documentation must also be kept on all forms of training and must comply with necessary regulations. ANSI guidelines require that training be provided to the administrator of the program as well as any affected employees. Training on fall rescue and rescue equipment, scaffold use, and fall protection or restraint systems is also required. It should cover the inspection, use, maintenance, care, and limitations of the equipment. Once the program is finalized and put into practice, observational data must be collected so that the administrator can analyze its effectiveness and recommend changes. Compliance monitoring will be important in order to find gaps in training or procedures. Feedback must be received by those performing the work. This will assist the administra-
tor in identifying more user-friendly procedures or equipment for specific applications. The program will change as new best practices and regulations are adopted. It is important to stay up to date with any major regulatory changes. As with all subjects relating to safety, communication is the key to success. As leaders and professionals in industry and construction, it is critical that we strive to set up our teams for success. Developing and maintaining a comprehensive working at heights program is a proactive way to reverse the statistics of the past, ensuring that workers are given every opportunity to perform the work required without falling and without being struck by falling objects. We have come a long way from the days of workers boldly walking across the beams of skyscrapers, but we still have more work to do. For more information, please visit www.vipinc. com. q
Sulfuric Acid Today • Spring/Summer 2020
When equipment reliability and performance are essential, trust Howden
Sulphuric acid production and sulphur recovery applications require technologies to perform under severe operating conditions. Howden specializes in the design, application and manufacture of customized turbo blowers and compressors for both production and recovery. As a leading turbo machinery manufacturer, Howden sets the standards for turbo blowers and compressors with proven efficiency, reliability and reduced running costs. We have drawn on extensive expertise from our product brands such as Kuehnle, Kopp & Kausch and Roots to design a wide range of bespoke solutions for sulphuric acid production and sulphur recovery units.
Discover more:
www.howden.com/blowers
Feature
How does sulfur purification affect opex of an acid plant? By: Jan Hermans, Director, Sulphurnet
Due to sulfuric acid’s corrosive property, acid plants need regular maintenance and
repairs, which are performed during plant shutdowns. Normally, this is scheduled well in advance and the costs are calculated. To control costs, producers prefer shutdown frequencies to be every 28 months or longer.
High ash levels in sulfur affect the pressure drop in the first catalyst bed of the
converter. This pressure drop leads to premature acid plant shutdowns, creating extra costs and maintenance (see Fig. 1).
When a plant shutdown is performed, we also need to take into consideration the
following tasks and their costs: Task
Fig. 1: Pressure drop build-up with various ash levels
Costs
Cool down of the plant Take out and screen catalyst
External Labor Loss of production
Re-install catalyst
External Labor
Pre-heat the plant
Fuel cost
These costs can easily run to $1 million when we talk about a 10-day plant shutdown.
There are ways to measure the ash content in the filtered sulfur. One of the most
So the question is: how can we minimize these costs?
common techniques is taking samples of filtered sulfur after the precoat cycle. Once the
samples are taken to the lab for analysis, results take about 3-4 hours. In the meantime, the
Fig. 2: Normal turbidity operation.
filtration process can be influenced by various parameters (including pressure fluctuations,
damaged leaf filters, etc.) so the data coming from the analysis may no longer be valid. Then, depending on procedures, new samples can be taken and analysed every 3 hours, which is time consuming and sometimes doesn’t leave time for action.
But laboratory results just provide snapshot readings which may soon become invalid.
Between readings, ash levels can increase, accumulate in the storage tanks, and eventually be transferred via the burner to the converter.
Our preferred solution is to control the ash level and be sure that the values are
For that application, Sulphurnet offers a turbidity analyzer, which can be installed
controlled and monitored in real time.
after the pressure leaf filters. Here, the ash level is monitored 24/7. Based on the quantity of ashes after the filter, the process can be controlled. When ash levels rise to an unacceptable
level, the DCS provides an alarm and adequate actions can be taken, preventing the transfer
Fig. 3 High turbidity operation.
of ash to the storage tank.
Based on a 1,500 MTPD sulfuric acid plant, a shutdown costs about $1,290,000.
But a turbidity analyzer plus a Sulphurnet liquid sulfur polishing filter (LSPF) costs only $400,000.
The installation of a turbidity analyzer as well as a liquid sulfur polishing filter
requires an investment but also extends the time between turnarounds. Compared to the
cost of more frequent turnarounds, the installation pays for itself, as the payback analysis in Fig.4 shows.
So, real time monitoring of the ash level will help to establish a longer operational
time between the maintenance intervals of an acid plant. A liquid sulfur polishing filter in combination with the turbidity analyzer will contribute to lower operating expenses of a sulfuric acid plant.
For more information, visit www.sulphurnet.com. q
PAGE 22
Fig 4: Return of investment: LSPF and turbidity analyzer.
Sulfuric Acid Today • Spring/Summer 2020
SUPERIOR SPRAY. SERIOUS RESULTS. MINIMIZE
BETTER
OPTIMIZE
PLUGGING
EVAPORATION
PERFORMANCE
New CBA sulfur gun reduces the risk of pluggage and maximizes production time. The nozzle is recessed in the steam jacketed gun to ensure the sulfur remains at the optimal temperature even when flow rate is reduced. CBA sulfur nozzles provide the same performance as our BA WhirlJet® nozzles – the industry standard – small droplet size and narrow droplet spectrum.
FloMax® two-fluid nozzles produce smaller droplets than conventional hydraulic nozzles. The result is enhanced evaporation and combustion. Choose from designs for sulfur spraying and sulfuric acid regeneration (SAR).
Maximize sulfur gun performance and minimize the chance for problems such as sulfur impingement on walls with our modeling services. Using Computational Fluid Dynamics, we can determine the best gun placement in the furnace, ideal drop size for complete vaporization and more to ensure maximum production and minimal maintenance.
LEARN MORE ABOUT ALL OUR SULFUR GUNS, NOZZLES AND MODELING SERVICES. For unmatched service and support, visit spray.com/localexpert or call 1.800.95.SPRAY
Feature
Wet electrostatic precipitators: the proven technology for sulfuric acid gas cleaning By: Gary Siegel, Marketing Director, Beltran Technologies, Inc.
Fifty years ago the engineering team at Beltran Technologies set out to design advanced dry and wet electrostatic precipitators. These systems produced excellent emission control results in plant operations of textile wet finishing, pulp and paper, electronics, metallurgical mining, and more. Since the wet electrostatic precipitator (WESP) achieved emission control of gas streams by removing up to 99.9% of the submicron particulate matter, it was evident the WESP system would be a perfect solution for sulfuric acid gas cleaning. An efficient sulfuric acid manufacturing process requires the maximum possible removal from input gas streams of fine particulates, acid mists, condensable organic compounds, and other contaminants. This high level of gas-cleaning efficiency is necessary to prevent poisoning of the catalysts and fouling or plugging of the catalyst beds. An optimum pure input gas is essential for avoiding the formation of a “black” or contaminated acid end-product. Most wet electrostatic precipitators are designed with the same common principal, yet there are differences in the engineering. The most efficient design when considering compactness, economic design, and collection efficiency is the square tube collector configuration. The square tube collector completely utilizes the cross-section of a square or rectangular vessel, and can be effectively used in both round and hexagonal vessels. Due to the square tube’s high utilization of the vessel cross-section, it can be operated at a lower velocity, so that the required tube length is shorter, making it more efficient and easier to wash, since the wash sprays penetrate the collector. Further, the high voltage frame is more rigid, does not swing, and stays more accurately aligned, resulting in more efficient and reliable performance. Because of the shorter tube length, lower stabilizing insulators are not required, and the insulators can be mounted on the clean gas side of the WESP, reducing the requirement for heated purge air and more reliable WESP operation. Beltran WESPs are designed with multi-pointed star discharge electrodes that charge and repel some of the submicron particles, which enables the next star to increase its corona power, and so forth as the phenomenon repeats almost 100 times as the gases flow up the tube. This type of electrode can produce considerable efficiency in single or multiple pass WESPs, usually utilized in acid plants. The system is designed using a vertical flow upward through the precipitator with continuous aqueous flushing. The system usually has PAGE 24
Fertilizer plant in the Republic of Korea employs Beltran WESP technology to clean the sulfuric acid unit’s input gas stream.
WESP installation controls emissions at a gold mining operation in Brazil.
two sets of spray headers. The first set continually cools and saturates the flue gases. The second set, positioned at the top and directly below the collector, washes the collector and the electrodes, operating on a periodic and as-needed basis. The continuous flushing greatly minimizes the problem of re-entrainment of particles from the collection surfaces back into the gas streams that dry operating electrostatic precipitators experience due to the use of mechanical or acoustical rapping units. The Beltran WESP design eliminates the need for rappers.
WESPs can be utilized in various configurations, such as: a single WESP; two WESPs in series; two WESPs in parallel; and multi-WESPs in parallel and two in series. Smaller gas flows are usually treated with one WESP. This also depends on the efficiency requirements; however, one WESP unit can produce reliable service at 99.5% efficiency, for smaller flows. Typically plants have two WESPs in series, so that one WESP can be washed while one operates. Sometimes two WESPs are designed to be utilized
Copper smelter operation in Zambia captures emissions with WESP technology from Beltran.
in parallel, for similar purposes. Two in series has the advantage of the first WESP overcoming the current suppression condition, while the second WESP operates at full power. This will depend on the gas flow rate, inlet and outlet process conditions, amount of particulate, mist, and aerosol at inlet and outlet, etc. Larger plants will require more WESPs in parallel and usually two WESPs in series; so one WESP can be taken off line for washing or maintenance, or washed online. The corrosive nature of the flue gasses at most sulfuric acid plants requires that special attention be given to the materials used in constructing the precipitators. Beltran WESPs are fabricated using fiberglass reinforced plastic (FRP) and high nickel-chromium alloys. Although precipitators used in acid mist applications historically have been made with lead, engineers have found FRP components to be less expensive, easier to construct and maintain, and extremely corrosion resistant. The electrically conductive sections of the WESPs are made from a special, conductive FRP material. The high-voltage insulators are kept continuously clean using a purge-air system, further reducing maintenance costs. Wet electrostatic precipitators are employed in various metallurgical processes such as zinc roasting plants, nickel flash smelters, lead sinter plants, copper flash smelters, as well as sulfuric acid regeneration plants. Beltran’s advanced WESP design is the most efficient, cost-effective acid mist and submicron particulate collector. Its collection mechanism is electrical charging as opposed to the inertia impaction mechanism of scrubbers or other gas cleaning equipment. Beltran Technologies has more than 1000 installations and more than 100 WESP installations operating in sulfuric acid plants worldwide. For more information, visit www.beltrantechnologies.com. q Sulfuric Acid Today • Spring/Summer 2020
Tower Hot water
Hot acid Cold fluid
Hot fluid Cold acid
Cold water
Failure safe
Recovery more energy Clark Solutions SAFEHRÂŽ is a patented sulfuric acid heat recovery technology which can increase high pressure steam generation in an acid plant by almost 20% and total energy recovery by as much as 35%, while addressing issues such as safety and corrosion in an absolutely innovative way.
Waste energy recovery Cooling water demand reduction
Learn more: clarksolutions.com
USA 411 SE Minzer BLVD #72 Boca Raton FL 33432-6001
Brazil 91 Dn. Joaninha - Moinho Velho SĂŁo Paulo / SP 06807-690
China Tian An Chuangxin Technology Plaza Futian District, Shenzhen
Chile Volcan Lascar 801, 2H Pudahuel - Santiago - Chile
Thermal and Mechanical Separation Solutions
/clarksolutions.com
|
/clarksolutionsoficial
|
/company/clark-solutions-brasil
|
/@clarksolutions
Feature
Further reflections of an acid cooler technical representative
By: R. Barry Krentz, President, Mercad Equipment, Inc.
Continuing from the previous issue of Sulfuric Acid
Today, I hope you’ll enjoy a few more experiences I’ve had in the industry.
Story 7: Weak acid can be a killer of SS acid coolers
A sulfur burning acid plant was shut down when an
acid cooler leak was detected by the dropping pH of the
cooling tower water. The outside operator was dispatched
to chain off the cooling water supply header followed by the return cooling water header to isolate the cooler from the
cooling circuit. However, before this was accomplished and
prior to water being drained, the inside operator shut down
the acid pump. There may have been a 10-minute delay be-
fore draining reduced the high water pressure—by this time the cooler was literally hopping on its foundations because of corrosive effects of water and hot acid boiling inside.
Before all the water could be drained out, they had
to stop the cooler draining as the containment pond limit had been reached. After a few hours the cooler draining
voltage was 5 VDC and the anodic current only at 2 amps.
Furthermore, the Control Reference Electrode (RE) voltage at the hot end was -100 mV and the RE R1 voltage at the
other end was 300 mV (they had switched “Control” function to the R1 acid outlet RE to keep the system running).
The plant was taken down and the cooler drained of
acid. REs were pulled and found to be okay. The main DE
cathode was removed in two short, stubby pieces, one from each end. The entire center core was completely gone!
Main cathodes are sacrificial and all the exposed cath-
ode area was found to be corroded away. Obviously this was the first time this cooler’s cathode had been removed
for inspection. A spare cathode was available and inserted
and the cooler recommissioned without further known consequences. I say “known” consequences as the tube wear at
the acid inlet may have been excessive due to lack of passivation during months or even years of low RE mV readings.
Story 9: Adding chemicals to acid in
was continued and completed. The cooler was opened by
the process is tricky business
with his anodic protection (AP). For no apparent reason, the
removing the end covers and the sight was not pretty.
About halfway down was a vivid line across the tube
sheets where hot weak acid had etched away the lower half
of the tube sheet, tube-to-tube sheet welds, and tubes. The lower half of the cooler was a write-off for obvious reasons.
The upper tube bundle was in much better condition,
but the tubes in the cluster around the leak had severely corroded tubes on the acid side where water reversed flow
from the original acid-to-water direction to the water-toacid direction when the acid pump was shut off.
Besides replacing the severely corroded cooler, two
The containment pond situation was improved so that
other improvements were implemented:
the entire cooler could be immediately drained of acidified water.
The operators were schooled to NEVER turn off the
acid pump until all the water was drained from the cooler.
Story 8: Double-ended (DE) cathodes have many advantages
Many years ago a technical representative flew to
Sardinia off the West coast of Italy. The client was hav-
ing problems with their main acid cooler that cooled all the acid in their plant. The rep arrived and checked over the operation of the anodic equipment to discover that the cathode PAGE 26
Case A: A client called one day requesting assistance
amps were high and alarms were going off. The question was asked of them: “What’s different about the process?” It took some time, but they finally determined that someone
Hot weak acid caused by a cooling tower leak badly corroded these acid cooler tubes and tubesheet.
AP is present, then lower doses are required and controller set points need lowering for the AP system to achieve low corrosion rates. In the end, seeking lower anodic amps for the AP system would be our goal. Lower anodic amps gen-
was feeding in a side stream of liquid waste from another
erally mean lower corrosion rates.
laced with chlorides and other non-mentionable goodies
Story 10: Some cooler main cathodes
change and went berserk. The solution to the problem was
are very difficult to get back inside
customer, getting rid of it in the acid circuit. The waste was
and you guessed it, the AP system immediately saw the obvious; stop feeding it into the acid circuit. When they did
that, the AP system lined right out. I’m not sure whether they later reduced the feed to something less disturbing. Also, I’m not sure what these chlorides and other entities were doing to downstream towers, demisters, etc.
Case B: For years, peroxide and other chemicals have
been used to produce “water-white” acid. The problem with
this is that some operators have been adding these chemi-
the cooler
Depending on the distances between baffles inside the
cooler, the standard 5/8” OD cathodes may be very difficult to reinsert. In some cases you may need to bend the PTFE tip to allow the cathode to “find” the next baffle hole. The first baffle may be an especially long reach and the cathode standpipe may need to be stressed downward (e.g. by
cals to AP circuits resulting in huge shifts in reference elec-
standing on it) to get some elevation to line up the droopy
AP system to “know” what is going on inside the cooler,
up seriously corrosive situations. To avoid AP interaction,
made from 7/8” OD material which sags very little as it is
acid circuit to avoid higher amps and corrosion. Alternately,
trode potentials. These electrode signals are the heart of the
cathode to the first baffle hole.
piping, or tanks. Chemical agents that shift readings can set
OEM cathodes. That would be the Mercad Super Cathode
these chemical reagents should be added after the protected
being inserted into the cooler. Problem solved!
when they need to coexist, such as in a storage tank where
There is a much better solution to these troublesome
For more information, contact Barry Krentz at
rkrentz@mercad.com or (416) 895-7124. q Sulfuric Acid Today • Spring/Summer 2020
THE ART OF ACID PROOFING
SOUTHWEST REFRACTORY DELIVERS THE HIGHEST QUALITY ACID PROOFING, REFRACTORY, INDUSTRIAL MASONRY AND FIREPROOFING WORK.
With in-depth engineering support, meticulous craftsmanship and extensive planning down to the finest details, we’re turning industry into artistry.
VIE W OUR GAL L E RY OF ACID P ROOF ING AND OTH ER RE F RACTORY P ROJE CTS AT SWRRE F RACTORY.C O M. (281) 824 9342
INFO@SWR-US.COM
Feature
CSX™: A modern solution for sulfuric acid plant piping
By: Nelson Clark and Bruno Ferraro of Clark Solutions; and Dimitrios Tsiaprakas and Ricardo Moretti of Elekeiroz
Ever since its development in the mid-80s, the use of high silicon stainless steel (HSSS) alloys in sulfuric acid applications has increased. Clark Solutions CSX™ HSSS equipment, manufactured with UNS S32615 and designed for a wide range of sulfuric acid applications, shows enormous advantages over cast iron piping and is steadily becoming a new industry standard. To further explore CSX™ HSSS piping advantages and benefits, the following sections examine some common sulfuric acid industry piping configurations and the reasons why high silicon stainless steel alloy piping is the best choice for most strong sulfuric acid systems.
Cast iron piping
A broad range of different acid piping materials have been used over the years, evolving with plant design and development of more sophisticated materials. The most common piping solution is either ductile or nodular gray cast iron systems, which themselves have a wide range of material composition and metallurgy. Cast iron, however, corrodes readily when placed in sulfuric acid service. Pipe or fitting lifespan is therefore a function of wall thickness, and consequently, thicker and heavier piping or equipment is necessary to counterbalance this disadvantage. In fact, pipe thickness in sulfuric acid industry is usually twice as bulky as standard values found across other industrial applications for the same pressures. Sulfuric acid piping corrosion is a very important issue. It is naturally related to maintenance, strongly relevant to safety, and has a direct impact over the acid quality produced in terms of iron content in acid. Piping corrosion byproducts form sulfate fouling, which can plug and restrict valve maneuver. Even worse, small amounts of iron in acid can radically change product appearance, giving it a milky, turbid coloration. In addition, fittings tend to corrode more easily due to higher local velocities caused by fouling, especially because cast iron is not resistant to erosion. Because of lower erosion resistance, ductile cast iron pipes are designed for lower velocities, which increases diameter, weight and thus material and installation costs.
Acid leakage in cast iron piping
Although corrosion is a very important issue, the greatest concerns regarding cast iron piping are acid leakage, maintenance, and safety. Consider the example of pipe spools manu-
Fig. 1: Experimental results on 98.5wt% sulfuric acid: turbidity (NTU–Nephelometric Turbidity Units) vs Fe concentration (ppm).
Turbidity Standards for reference (not sulfuric acid). From left to right, in NTU: 0, 50, 100, 250, 500 and 1,000 [1] PAGE 28
CSX™ HSSS piping supplied by Clark Solutions.
facturing, which can be either centrifugated or cast. Centrifugated spools can be as long as six meters. Centrifugation guarantees air free homogeneous walls. But flanges are threaded. Conical threads and adhesives are used to mitigate leakage risks, but they cannot completely remove leakage potential. Cast spools are usually limited to two meters in length and rely on integral flanges to minimize leak risk. The static casting process does not fully guarantee wall thickness uniformity, eventually keeping air and contaminants in the bulk of the wall and multiplying by three the number of flanges and gaskets needed on an equivalent length. Whether cast or centrifugated, welding is not possible. The system is designed with standardized parts that usually require a special adjustment spool to the final assembly, creating extra potential leakage points. Cast iron fittings, tees, elbows, and reductions are also cast. The manufacturing process uses two molds, between which the molten metal is poured. To prevent the core mold from floating, chaplets are used to hold each mold piece in position. Temperature at this stage must be controlled because if it is too hot, the chaplets would completely melt, and the core mold would float, generating a decentralized pipe. On the other hand, if the temperature is too low, a partial melt of chaplets cannot be achieved, which generates weak points from both corrosion and metal uniformity standpoints. This manufacturing temperature for partial chaplet melting and proper bounding is difficult to control, and lapses in the proper conditions are the cause of most leaks [2]. A leaking spool or fitting is a condemned piece; it cannot be welded and cannot be reused. When an acid leakage occurs, maintenance time may be long, sometimes taking days, depending on the size and diameter of the failed pieces. A new adjustment spool will be needed, all gaskets will have to be re-tightened and some replaced. Also, very heavy equipment handling requires extra safety precautions. As cast iron parts are unique, it is not feasible to cut small spools from a standard spool. The plant must have a large spare parts inventory. Sometimes, fittings are specially sized, or the pipe supplier is from abroad and there is a long shipping lag. Day-long stops mean plant cooling. Moisture and condensation occur, and corrosion will take place. Re-heating may be necessary. When shipping takes longer than the maintenance shutdown, some plants have to emergency fit parts that differ in size from the originals, so that the plant can continue operating until the correct parts arrive. This often leads to a change in line flexibility. Size difference and altered thermal expansion for this temporary solution may cause the system to behave in ways that create more leakage points. Leakage maintenance costs are another factor. A study performed by Elekeiroz in 2017 reveals that during the previous year, their production availability losses due to maintenance shutdowns were strongly related to acid leakage, and the
Fig. 2: Corrosion rate for low and high Si ductile iron piping for 6 FPS 98% acid flow.
main sources were acid pipelines. The maintenance expense of acid pipe repairs, plus production availability losses with secondary factors such as temporary loss of acid quality control during downtimes, increase the economic advantages of a more reliable piping solution using CSX™ HSSS. Also, a huge advantage is the added safety benefit that goes along with avoiding acid leaks.
CSX™ piping
In recent years, much has been done to develop new, more efficient and affordable materials. In this context, CSX™ HSSS provides several advantages when compared to ductile cast iron for acid piping systems, including significantly reducing failures and consequently production losses and maintenance costs. The key to the success for CSX™ HSSS is the formation of a very resistant passive layer of silicon oxide on the material’s surface in the presence of a strong oxidant. This brings a very high resistance to strong sulfuric acid at typical process temperatures. This provides additional beneficial properties to the alloy, such as high pitting and erosion corrosion resistance, the latter being especially attractive for piping systems since fittings are more susceptible to erosion damages. CSX™ piping is fitted together through welding, which eliminates the need for flanged connections by up to 80 percent, drastically reducing acid leak problems and therefore risk to personnel and property. Since the alloy is much more corrosion resistant, pipe thickness is also significantly reduced, substantially reducing weight, the cost of the pipe and its supports, as well as installation costs. Greater alloy erosion resistance also makes it possible to operate with acid at higher velocity, up to five times greater than cast iron, reducing pipe diameters, retained acid pipe inventory and overall cost of installation. Table 1 shows the corrosion rate comparison between two types of ductile iron pipes and CSX™ HSSS, all for 98%wt sulfuric acid at 6 FPS.
Fig. 3: Losses by production unavailability (Elekeiroz maintenance data, 2016). Sulfuric Acid Today • Spring/Summer 2020
Temperature (oF)
Corrosion Rate (mpy) Low Si Ductile Iron
High Si Ductile Iron
CSX™ HSSS
190
50
30
<1
200
65
35
<1
210
90
45
<1
220
100
70
<1
230
105
90
<1
240
110
100
<1
250
115
105
<1
Table 1: Corrosion rate comparison for 98%wt sulfuric acid at 6 FPS.
Given a 200 MTPD sulfuric acid plant acid with 98%wt acid flowing at 6 ft/s at 250oF, and CSX™ piping measuring 60 ft long by 6 inches in diameter, the iron concentration would be 0.3 ppmw on the product acid, while a high silicon cast iron piping would have 30 ppmw iron concentration. Therefore, cast iron piping is limited to low sulfuric acid temperature and velocity to achieve a decent turbidity standard, whereas CSX™ has no such limitations. The system can normally have reduced diameters even when accounting for pressure drop concerns. The reason for this is that the surface roughness of passivated stainless-steel is smoother than cast iron, and thus increased velocity is compensated by reduced rugosity and fewer singularities. In practice, typical upper limit CSX™ flow velocities are limited not by erosion itself, but by the resulting similar pressure drop equivalent of the piping system project. Moreover, since the system can be welded, any bore or crack can be repaired with simple welding and a short stop, which is a huge benefit in comparison to cast iron systems that require spools, fittings, or connections to be completely replaced via disassembly by crane. The combination of qualities brings a huge range of benefits to CSX™ piping solutions: Clark Solutions CSX™ piping systems are manufacDN (in)
Cast Iron Weight (kg)
CSX™ HSSS Weight (kg)
3
109
38
4
159
65
6
278
97
8
388
127
10
523
159
12
685
190
14
862
208
16
1043
356
18
1244
401
20
1498
446
24
1971
537
Table 2: Weight comparison of flangeless 6-meter-long pipe. Sulfuric Acid Today • Spring/Summer 2020
Ductile Cast Iron
Low number of flanges = Low leak potential (up to 80% quantity reduction)
High number of flanges = High leak potential (flanged connection on every piping piece)
Lower thickness = Lower weight and installation costs (typically 3 to 6 mm thick)
High thickness = Heavy weight, high installation costs (typically 15.5 to 22.3 mm thick)
Higher final product quality (elimination of iron sulfate)
Lower final product quality (inherent presence of iron sulfate)
Low maintenance cost and length due to welding
High maintenance cost and length due to cranes
Minimal inventory of spare parts
Large inventory of fittings
Higher design velocities = Lower pipe diameters (practical limits up to 5 m/s due to system pressure drop limitations)
Low velocities = Large pipe diameters (typical desired range around 1 m/s or higher, per example of 1.5-2.0 m/s on more sophisticated cast iron systems, but limited by acid temperature due to erosion)
Feature
Fig. 4: CSX™ HSSS isocorrosion curve as a function of sulfuric acid strength and temperature.
CSX™ High Silicon Alloy
Cast iron piping replacement with CSX™ HSSS (Elekeiroz, 2020).
Table 3 - Advantages of CSX over cast iron on sulfuric acid plant applications
tured by pre-conforming metal sheets by automatic stamping machines. Welding, procedures, qualifications, and tests are performed in accordance to ASME BPVC IX. Manufacturing standards such as ASME B31.3, ASME B16.9, ASME/ASTM SA-403/A-403, ASME/ASTM SA-240/A-240 and others are followed according to the client requirement. The system is quality controlled by complete liquid penetrant, radiographic and hydrostatic tests and, if requested, heat treatment and SNQC-qualified inspection can be performed. All information is compiled in a complete data-book to provide a reliable and advanced solution for sulfuric acid piping systems. In cases of piping replacement, Clark Solutions also provides new isometric drawings per client request.
Welding of CSX™ HSSS.
Other applications
CSX™ HSSS provides such resistance to corrosion and erosion from hot, strong sulfuric acid that it is used for many other applications. Acid distributors made with CSX™ HSSS have many benefits over cast iron. Besides corrosion resistance and weight aspects, CSX™ HSSS acid distributors, such as MaxiFlow™, offer less cross-sectional area blockage and more irrigation points due to reduced thickness. The thick troughs of cast iron acid distributors create high gas velocity zones that increase acid mist generation. Also, thinner CSX™ HSSS downcomers allow more irrigation points, up to 4 pts/ft2 against 1.5 pts/ft2 in cast iron, which enhance mass transfer. Meshpad mist eliminators, such as MaxiMesh®, commonly applied in drying towers can be manufactured with knitted CSX™ HSSS mesh in addition to co-knitted fiber glass or PTFE, for higher droplet collection efficiency. Drying and absorption tower shell material can either be brick lined carbon steel or CSX™ HSSS, the latter providing a tower with smaller diameter. A lighter and brickless tower represents less maintenance and lower civil basis load requirement. Acid coolers manufactured in CSX™ HSSS grant important benefits over the stainless steel anodic protected solution. The latter requires a cathode replacement sporadically (roughly every two years) and have acid temperature limitations to guarantee passivation; limitations that CSX™ HSSS doesn’t have. Many other parts, such as filters, vortex breakers, and custom made pieces are also possible applications.
Conclusion
Acid leakage is a relevant concern in the sulfuric acid industry, in terms of both personnel safety and the economics
CSX™ HSSS acid distributors.
of increased maintenance. High silicon alloy stainless steel piping systems are becoming more popular since their proven maintenance and safety advantages shows their cost-benefit for long term operation. High corrosion resistance, reduced wall thickness, and weldability are benefits that allow higher acid flow rate, smaller diameter, lower weight, quicker maintenance, fewer flanges and fewer leakage points, all of which increase plant reliability and facilitate operation. For more information, visit the products page at www. clarksolutions.com.br. q
References
[1] Frahm, G. E. et al (2016). Evaluation of Microflow
Digital Imaging Particple Analysis for Sub-Visible Particles Formulated with an Opaque Vaccine Adjuvant. doi: 10.1371/journal.pone.0150229
[2] Louie, D. K. (2005). Handbook of Sulphuric Acid
Manufacturing. Ontario, VIC: DKL Engineering, Inc.
PAGE 29
Feature
Inline sulfuric acid monitoring MAGDEBURG-BARLEBEN, Germany–Sulfuric acid is one of the most important basic chemicals. Steady demand grows because H2SO4 is used for preparing a variety of products. In most applications, very accurate monitoring of sulfuric acid concentration is required to ensure excellent product quality. Due to the physical properties of sulfuric acid and oleum, the most suitable measuring method for determining acid strength is the sonic velocity measurement. Using this method, SensoTech’s LiquiSonic® sensors can measure sulfuric acid concentrations within ± 0.05 wt% H2SO4. In contrast, measuring principles like conductivity and density won’t yield clear results for concentrations between 80–100 wt% H2SO4. This rapid, robust measuring technology improves plant utilization, process safety, and product yield. For aggressive process liquids special materials are
available, like Hastelloy C-2000 or Tantalum. The systems consist of one controller and 1 to 4 sensors. They are maintenance free and work without moving parts, which ensures long-term stability. These analyzers can easily be integrated into the process, which reduces manual laboratory measurements and saves laboratory and material costs. To enhance process control and safety, LiquiSonic® systems provide many benefits: — Easy, user-friendly installation (plug & play) and operation. — Excellent long-term stability — One sensor for all applicaLeader in Restoration and tions (reduced investment costs). — Comprehensive diagnostic capabilities. — Suitability for all needed concentration ranges with high accuracy. — Conductivity and density show inflection points.
SensoTech’s LiquiSonic® system measures the concentration of sulfuric acid inline and in real-time.
efficient way to monitor sulfu Typical applications for ric acid processes in any kind LiquiSonic® measurements of Rebuilding of Rotating Equipment of industry. They are capable of sulfuric acid and oleum concenmeasuring the entire range of trations include H2SO4 and oleum sulfuric acid and oleum. production, fertilizer production, For three decades SensoTech synthesis gas drying, etching and GmbH has developed inline pickling baths, mining processes, analysis systems for processes and refinery catalysis. in liquids. SensoTech’s analyz SensoTech’s real-time inline ers set standards in technologiconcentration analyzers are the
cal and qualitative value, userfriendliness, and reproducibility of the measured values. Special calculation methods and highly developed sensor technologies enable reliable and fast measurement results even under difficult process conditions. For more information visit www.sensotech.com q
Leader In Restoration and Rebuilding of
Service & Installation
Repair
Full Service Shop Capabilities
Repair and Replacement:
• Engineering Analysis
• Compressors
• Material Upgrades
• Blower Impellers
• Complete System Audits
• Rotor Assemblies
• At-speed Balancing
• Steam Turbines
• Over-speed Testing
• Gear Boxes
Support • Engineering • Manufacturing • Onsite Replacement Parts SoCal Facility 7411 Telegraph Road Montebello, CA 90640 Ph: 323-726-5200 Fax: 323-726-5206
PAGE 30
Norcal Facility 1101 Nimitz Ave Bldg 126 Vallejo, CA 94592 Ph: 707-656-0038 Fax: 707-656-0047
Visit us online at
Sulfuric Acid Today • Spring/Summer 2020
ALPHA-CORR TYPE III ACID BRICK
AvAilAble
in the
USA todAy
From our strategic location in Houston, TX, we are able to supply a variety of brick shapes (straights, arches, wedges, keys) and sizes from stock for immediate purchase. Please reach out to us for technical data and pricing. Samples available upon request. Meeting ASTM C279 standards for use in new construction and refurbishment of existing structures in sulphuric acid plants including towers, process vessels, floors, sumps, pits, etc.
A-103 MASTIC速 A-103 Mastic速 is Still Available and in Stock in warehouses in USA and Canada. Made from the original recipe. When your plant has a product that has proven successful for over forty years, why change? With this in mind, Alphatherm Inc. purchased the recipe of Pecora A-103 Mastic速 to keep this integral piece of the Sulphuric Acid Tower lining system intact. Made from the same ingredients with A DECADES OLD RECIPE, A-103 continues to be the workhorse membrane in Acid Plants worldwide. Industrial Linings for Sulphuric Acid Plants. Absorption Towers, Pump Tanks, Sulphur Pits, Secondary Containment, Acid Resistant Linings.
Acid Brick, Acid Resistant Mortar, Membranes, Carbon Brick, Polymer Concrete, Refractories, Teflon, Ceramic Paper and Blanket, Ceramic Rope, Borosilicate Block
Alphatherm Inc.
|
Accept No Imitations!
This is THE ONLY A-103 Mastic速 made with the original Pecora recipe. A-103 MASTIC is a registered trademark of Alphatherm Inc.
www.alphatherm.com
|
Tel: (905) 948-9949
|
Email: alphatherm@ilap.com
Feature
Detecting real-time moisture leaks in acid plant process gas By: Daniel T. Menniti, Senior Director, Marketing and Sales, Breen
Sulfuric acid production requires a sulfur dioxide (SO2) gas source, most commonly supplied by: • Burning elemental sulfur. • SO2 off-gas from a primary process such as a copper smelter. • Decomposition of H2SO2 in a spent acid regeneration process. The SO2 gas is passed over a catalyst in the presence of oxygen to oxidize it to sulfur trioxide (SO3), which is then absorbed into 97–98 percent H2SO4 to form oleum (H 2S2O7), also known as fuming sulfuric acid. The oleum is then diluted with water to form concentrated sulfuric acid.
Acid dew point measurement
In sulfuric acid production, SO2 is oxidized over a solid vanadium catalyst to generate SO3. The SO3 is then absorbed in water contained in 98 percent sulfuric acid to form new sulfuric acid. The gas laden with SO3 in the process is kept moisture free and the only time moisture gets introduced in the gas is when there is a process upset. This is a highly undesirable condition and can be potentially hazardous. Moisture in the flue gas combines with the SO3, which condenses on the process equipment surfaces. This effect is generally indicative of one of the following conditions, among others: • Drying tower malfunction • Moisture in feed • Waste heat boiler tube leaks • Economizer tube leaks • Cleaning system malfunctions The presence of moisture and therefore weak acid vapor in the gas stream is detrimental to equipment health and can cause extreme corrosion. A secondary impact of moisture in the flue gas can be the formation of
hydrogen gas, which creates an explosion hazard [1]. The H2 formed in the following equations can create an explosion in the presence of O2 and an ignition source. • SO3+H2O —> H2SO4 • Fe+H2SO4 —> FeSO4+H2
Moisture leak detection
As stated, there are several potential sources of moisture ingress into the process gas stream including the drying tower, feed stock, waste heat boiler tubes, and economizer tubes. Monitoring each of these individual process points (Fig. 1) for malfunction and moisture ingress becomes expensive and manpower intensive. Traditionally, operators measured the acid dew point to indicate such moisture leaks. In theory this would provide a step change response should moisture enter the upstream process. The commercial design for the Breen-SA Probe can be seen in Fig. 2. After successful factory testing, the probe was taken to a sulfuric acid manufacturing plant and installed at the exit of the economizer along the production train. The economizer outlet location presents itself with a process gas temperature of approximately 400oF and a process gas pressure between 6 and 10PSI. The process gas dew point was expected to be at approximately 250oF. After initial installation, the dew point probe provided sound dew point results as seen in Fig. 4.
process gas dew point, but low enough to detect an increase, or step change, in process gas dew point. There were two objectives that needed to be met during operation in this mode: detect moisture ingress and provide a method to verify measurement integrity.
Moisture leak detection— commercial design
In late September/early October 2018, Breen installed the commercial design into a sulfuric acid plant in California (Fig. 5). The probe system was allowed to run at the above dew point mode, with a weekly “check cycle” cooling the sensor to the process gas dew point. The probe cycle and check cycles are shown in Fig. 6. On January 23, 2019, the plant performed a test to verify that the system would indeed detect a moisture leak. At approximately 10:45 (Fig. 7) we can see a probe response when a pressure point line was cleared out with instrument air. A compressor was then hooked up to the line to pump ambient air into the duct; no response was seen, and it was assumed that the air pressure was not powerful enough to push sufficient air into the duct.
Fig. 2: Breen-SA Probe Rev 2 for sulfuric acid plants.
Fig. 3: Breen-SA Probe Rev 2 installation.
Fig. 5: Breen SA Probe installation at J.R. Simplot’s Lathrop plant.
“Above dew point” measurement
To keep the sensor free of process condensables for the long term and also provide moisture leak detection, it was decided to operate the system at an “above dew point cycle.” The above dew point cycle would allow the probe to operate in the duct at a temperature higher than the
Fig. 6: Breen-SA Probe normal cycle and check cycle.
Fig. 4: Preliminary dew point measurements.
Fig. 1: Typical moisture ingress points in sulfuric acid manufacturing. PAGE 32
Fig. 7: Leak detection simulation. Sulfuric Acid Today • Spring/Summer 2020
installed in another acid plant in the Western United States. During start-up operations, this plant experienced a small leak. As shown in Fig. 8, the Breen-SA Probe detected the leak at about 5:00 on June 27th when the leak was still very small. The first plant DCS indication that there was an issue was about 13:30 on the 27th when the dilution water flow starts to drop, indicating the leak is large enough that less water is needed to maintain the acid concentration balance in the plant. Clearly, the probe provided almost eight hours of advance notice compared
Fig. 8: Leak detection from Breen-SA Probe vs. dilution water flow.
to the traditional method of leak detection at the plant. Additional features of the latest design include detection for sensor breakage and protection from back flow of the process gases though the probe. Periodically we have seen the probe sensor damaged when inserting the probe into the process, so shielding has been put in place to protect the sensor from breakage during installation.
Summary
It has been demonstrated that the dew point measurement system has the capability to measure continuous process gas dew point temperatures. Understanding that the industry desires long term, ultralow maintenance, it appears that the “above dew point mode” measurement philosophy has been commercialized and proven effective to detect moisture leaks, while maintaining a clean and dry sensor in between moisture events. It has also been shown that the probe consistently responds to moisture ingress into the process in real time and demonstrably quicker than traditional methods. This method also allows for the insitu
Feature
Subsequently, the process engineer put water into the pressure point line and used instrument air to push that water into the duct. The amount of water added was approximately a gallon. At 13:15 we can see the probe immediately responded to the event. It was concluded, with fairly strong certainty, that the probe is very responsive to even small amounts of moisture. There were also other minor responses in the previous weeks, which were believed to have been caused when other pressure point lines were cleaned out. In July 2019, a second system was
Fig. 9: During installation, SA Probe sensor, left, damaged from obstruction in port. At right, sensor protective shield.
verification of sensor function using a periodic system “check cycle” outputting a measured dew point on demand.
At the time of writing, the com-
mercial system has been running for 18
months with no failures or maintenance. During a turnaround last September, the probe was pulled for inspection and re-
installation. There were no signs or premature deterioration of the sensor or probe.
For more information on Breen sen-
sors or the full range of Breen products and services, visit www.breenes.com. q Reference: [1] Information developed and presented by the Hydrogen Safety Workgroup.
416.444.4880 admin@mercad.com ● www.mercad.com
Sulfuric Acid Today • Spring/Summer 2020
PAGE 33
Feature
CONFERENCE PREVIEW
Sulfuric Acid Today to host sulfuric acid workshop in Brisbane, Queensland Sulfuric Acid Today is happy to announce that this year’s Australasia Sulfuric Acid workshop will be held in Brisbane, Queensland. Due to the COVID19 virus, the event has been rescheduled for September 20-23, 2020. The popular two-and-a-half day event serves as an information exchange for participants from all sectors of the sulfuric acid industry, including fertilizer plants, smelters, regeneration facilities, and merchant plants. A cross-section of industry producers, suppliers, and contractors will share their experiences, relay common lessons, ask questions, and offer suggestions. The first Australasia Sulfuric Acid Workshop was held in Melbourne in 2002– since then, attendance has grown exponentially. Industry insiders from around the region, and the world, use the opportunity to meet, discuss issues facing their sectors, and share best practices. This year’s agenda will include a keynote address on the 2020 market, in-depth technical content, and panel discussions, as well as networking opportunities. The workshop will also feature a specially designed polling app to help increase the free exchange of ideas. Participants can answer poll questions during presentations and the results will be displayed live, providing real-time benchmarking information for attendees. Participants will also be able to ask questions anonymously during Q&A time following presentations. The value-packed program consists of three key elements: industry technology presentations, producing plant presentations during panel discussions, and networking. This year’s industry technology presentations include: — Keynote Address: “Sulfuric acid market: 2020 and beyond,” by Freda Gordon, Acuity Commodities — “Acid plant retrofit projects–The devil is in the detail,” by Matthew King, Chemetics — “A major acid plant upgrade: A converter, cold IP gas exchanger, economizer and interconnecting ducting PAGE 34
Conference participants will have the opportunity to take part in a golf tournament on Sunday, September 20, at the Victoria Park golf course in Brisbane.
The 2020 Australasia Sulfuric Acid Workshop will allow participants to peruse display booths and interact with key global companies co-sponsoring the event.
replaced in one easy shutdown,” by Guy Cooper, NORAM Engineering & Constructors — “The sulfuric acid X Files II,” by Angus Yip, DuPont MECS® — “Improving efficiency in sulfuric acid plants,” by Stefan Braeuner, Outotec — ”Hydrogen safety in acid plants,” by Darren Bridges, Specialised Engineering Services — “Aftermath of a hydrogen excursion,”
Sulfuric acid professionals from around the globe will converge in Brisbane to network and exchange best practices.
by Jack Harris, VIP International — Choosing the right absorbing tower mist elimination solution,” by Graeme Cousland, Begg Cousland Envirotec — “Advancements in sulfur filtration,” by Jan Hermans, Sulphurnet — “Overcome obstacles in the acid plant through right catalyst selection and technical service,” by Casper Frandsen, Haldor Topsoe — “How catalyst shape affects performance,” by Dirk Hensel, BASF — “Basic catalyst handling and best
practices,” by Jack Harris, VIP International — “Common problems encountered with vertical acid pumps,” by Mick Cooke, Weir Minerals Lewis Pumps — “Digitalization trends for improved compressor operations in sulfuric acid plants,” by Wolfhard Kiefer, Howden Turbo GmbH — “Digital on-line measurement towards process excellence,” by Shamsul Khan, SensoTech GmbH — “Aspects of sulfuric acid mist precipitator design, materials and maintenance, by Michael Beltran, Beltran Technologies Panel discussions among acid producer personnel will include the following topics: — Acid Towers: Packing/Mist Elimination/Distributors/Pressure Drop/Mist Carryover/Replacement — Converters: Replacement/ Maintenance/Catalyst Screening & Disposal — Sulfur and Sulfuric Acid Pumps/ Compressors — Process Gas Monitoring/Analyzers — Gas Cleaning — Sulfur Handling, Storage, and Pit Maintenance — Heat Exchangers: Acid Coolers Shell & Tube/Plate/Gas-Gas — Safety Issues and Incident Reviews Co-sponsors of this year’s event include: Acid Piping Technology, AWS, BASF, Begg Cousland, Beltran Technologies, Chemetics, DuPont MECS®, Haldor Topsoe, Howden Turbo GmbH, Integrated Turbomachinery, Koch Knight LLC, NORAM Engineering & Constructors, Outotec, SensoTech, Specialised Engineering Services (SES), Sulphurnet, VIP International, and Weir Minerals Lewis Pumps. For more information, contact Kathy Hayward, kathy@h2so4today.com or 985807-3868. Plant personnel interested in registering for the conference, visit www. acidworkshop.com. q Sulfuric Acid Today • Spring/Summer 2020
Beltran Sulfuric Acid Today Full Page 2019 Final.qxp 9/27/19 10:59 PM Page 1
ADVANCED WESP, HIGH-PERFORMANCE GAS-CLEANING FOR SULFURIC ACID PRODUCTION Beltran Wet Electrostatic Precipitators capture fine and submicron particulates, acid mists and condensed organics with maximum efficiency and lower operating cost. COPPER SMELTER WESP
Beltran gas-cleaning WESPs are the systems of choice specified by engineers and consulting engineering firms working at sulfuric acid plants worldwide, including mining and metallurgy and spent acid recovery. • High efficiency particulate reduction increases life time of Catalyst. • System can be customized to reduce heavy metal contaminants in sulfuric acid. • Unique electrode design and multistage systems capture flue-gas components like acid mist particulate and heavy metals with up to 99.9% efficiency. • Low pressure drop supports higher gas velocities and volumes with smaller equipment and lower costs.
ZINC SMELTER WESP
• Aqueous flushing system prevents residue build-up. • Cool, saturated WESP is more effective on condensable, oily, sticky contaminants. • Contaminant-free feedstock gas assures quality end-product for acid plants.
SCAN HERE with your Smart Phone for more info from Beltran
Beltran Wet Electrostatic Precipitators: The leading technology for sulfuric acid gas cleaning
BELTRAN TECHNOLOGIES, INC.
Beltran Technologies, Inc. 1133 East 35th Street, Brooklyn, NY 11210 718.338.3311 • Fax: 718.253.9028 info@beltrantechnologies.com www.beltrantechnologies.com GOLD REFINERY WESP
ENGINEERING THE FUTURE IN EMISSION CONTROL TECHNOLOGY! 60 YEARS OF EXPERIENCE. MORE THAN 1000 INSTALLATIONS WORLDWIDE.
Faces & Places
Sulphur 2019 Conference
November 4-7, 2019 • Houston, Texas
Rene Dijkstra of Chemetics explained his company’s world’s largest energy recovery system to participants of the Sulphur Conference during the sulfuric acid stream of the meeting.
Brian Christlieb of Phillips 66, center, visits with Begg Cousland’s Graeme Cousland, left, and Martyn Dean in their exhibition booth at the Sulphur Conference in Houston.
Attendees enjoying some Texas hospitality at the DuPont Clean Technologies dinner included, from left, Stuart Hinze of J.R. Simplot, Brennan White of J.R. Simplot, Jeremiah Fort Ramirez of J.R. Simplot, Yolanda Thomas of J.R. Simplot, Jason Warner of J.R. Simplot, Brett Rabe of Lithium Nevada, Vulcan Mutler of Exp OGC Group, Manuel Saez of Agrogen Mexico, Nicolas Xacur of Agrogen Mexico, and John Horne of DuPont Clean Technologies.
Rafaella Rodrigues of Mosaic P&K, left, and Luana Carlette of Mosaic, center, visit with Nelson Clark of Clark Solutions during the Sulphur Conference in Houston.
DuPont Clean Technologies hosted a dinner for their clients and customers during the Sulphur Conference in Houston. Pictured from left to right are Jack Harris of VIP International, Howard Tenney of Tenney & Assocaiates, Ted Olszanski of Eco Services, Gavin Floyd of Eco Services, Dennis Smerchanski of Border Chemical, Jim Dougherty of DuPont Clean Technologies, Steve Puricelli of Saconix LLC, Owen Soppet of PCI Corporation, and Amogha Romo of Dow-Deer Park.
Enjoying the dinner hosted by DuPont Clean Technologies are, from left, George Brown of Veolia, Garrett Palmquist of DuPont Clean Technologies, Toby Nihill of BHP Olympic Dam, Nathan Streitberger of BHP Olympic Dam, Kirk Schall of DuPont Clean Technologies, Carmo Pereira of DuPont Clean Technologies, Dror Margulis of ICL, Thierry Marin of DuPont Clean Technologies, and Bechir Alibet of Daveriyas– Tunisie.
Networking is an important part of the Sulphur Conference and participants took advantage of the opportunity during a dinner hosted by DuPont Clean Technologies. From left, Carlos Cavalca of DuPont Clean Technologies, Mark van den Boom of EXP, Brian Christlieb of Phillips 66, Kevin Bryan of Kevin Bryan Consulting, Kirk Bailey of DuPont Clean Technologies, Matt Thayer of Koch Knight LLC, Mark Dvorak of EXP, Eli Ben-Shoshan of DuPont Clean Technologies, and Jeannie Branzaru of DuPont Clean Technologies.
Wonderful food and idea sharing were on the menu at the DuPont Clean Technologies dinner during the Sulphur Conference in Houston. Enjoying both are, from left, Gianni Barouchell of Escafert, Alessandro Lanfranchi of Zolfindustria, Christina Kulczycki of DuPont Clean Technologies, Rick Davis of Davis & Associates, Charlotte Davis, Kathy Bailey, David Bailey of CMW, Travis Keys of DuPont Clean Technologies, and Sam Yu of QF.
John Orlando of NORAM Engineering & Constructors, right, visits with a participant in his company’s exhibition booth during the Sulphur Conference in Houston.
Harald Schroth, right, and Robbie Cortez, left, of SensoTech GmbH explain their inline system for measuring the concentration of sulfuric acid to attendees of the Sulphur Conference.
Evan Uchaker of DuPont Clean Technologies, left, and Doug Azwell of DuPont Clean Technologies, right, visit with attendees in their exhibition booth during the Sulphur Conference in Houston.
Michael Fenton of Chemetics explained how to turn costs into profits in heat recovery plants during the sulfuric acid workshop at the Sulphur Conference in Houston. Daniel Menetti of Breen Energy Solutions shared his company’s sulfuric acid plant process gas dewpoint and moisture lead detection measurement system with participants at the Sulphur Conference in Houston.
Jason Warner of J.R. Simplot, center, walks through a sulfuric acid converter utilizing virtual reality in Haldor Topsoe’s exhibition booth while Marten Granroth of Haldor Topsoe, right, explains the details.
Garrett Palmquist of DuPont Clean Technologies shared his company’s HRS® technology with the participants of the sulfuric acid workshop during the Sulphur Conference.
Marco Kennema of BASF explained his company’s sulfuric acid catalysts and the future of heterogenous chemistry during his presentation at the Sulphur Conference in Houston.
Hanno Hintze of Aurubis AG, center, visits with Matthias Walschburger of Koch Knight LLC, left, and Matt Thayer of Koch Knight LLC during the Sulphur Conference in Houston.
Rick Davis of Davis & Associates chaired the sulfuric acid workshop session on heat recovery from acid plants during the Sulphur Conference in Houston. Panelists, from left to right, are Nelson Clark of Clark Solutions, Klaus Knabel of Outotec, Garrett Palmquist of DuPont Clean Technologies, and Michael Fenton of Chemetics.
Klaus Knabel of Outotec explained his company’s design philosophies to improve plant safety and operability for heat recovery during the sulfuric acid workshop at the Sulphur Conference in Houston.
Michael Beltran of Beltran Technologies explained the design, materials, and safety features of sulfuric acid mist precipitators during the Sulphur Conference.
NORAM Engineering & Constructors hosted a dinner for their clients and friends during the Sulphur Conference in Houston. Pictured from left to right are Stuart Hinze of J.R. Simplot, Jeremiah Fort Ramirez of J.R. Simplot, Jason Warner of J.R. Simplot, Brennan White of J.R. Simplot, Mariesha Davis, Yolanda Thomas of J.R. Simplot, Joanne Orlando, John Orlando of NORAM, George Wang, Guy Cooper of NORAM, George Brown of Veolia, Brian Christlieb of Phillips 66, Andres MahechaBotero of NORAM, and Marcelino Padrón of Koura.
Feature
36th Oil | Gas | Fertilizers | Metallurgy | Industrial
Sulphur + Sulphuric Acid 2020 2-4 November, 2020 World Forum, The Hague, the Netherlands
The premier event for those working in sulphur and sulphuric acid production, consumption, and trade, to come together to meet, learn, share experiences, discuss challenges, and do business.
Over 50,0 Acid Re 00 sis
Whatever information you need to further develop your business for the year-ahead, this four-day event delivers the content and networking opportunities to enable business success.
ta Bricks nt
+ 450 delegates
IN STOC
K!
Now Manufacturing and Stocking
+ 50 presenters
Acid Resistant Brick
+ 70 exhibitors
and technical experts
networking opportunities
9 + hours
of technical content
Sponsors:
At Koch Knight LLC, our goal is to provide engineered solutions by focusing on specific customer needs. By applying our extensive experience in the industry and on-going product development, Koch Knight has developed brick lining materials capable of providing reliable service in the most demanding corrosive applications. Whatever your corrosive application, Koch Knight has the acid-proof solution.
Official Publications:
East Canton, Ohio (USA) - Baytown, Texas (USA) Santiago, Chile - Parramatta, Australia - Seoul, Korea - Istanbul, Turkey Visit us on the web: kochknight.com | Phone: +1 (330) 488-1651
KochKnightSulfuricAcidQtrPageAd.indd 1
For more information and to book you place, please visit: www.sulphurconference.com
9/14/17 4:06 PM
SU20 4 7/8 inches x 5 7/8 inches.indd 1
2020
Australasia H SO W O R K S H O P 2
+ 12 hours of
4
S U L F U R I C A C I D T O D AY
Save the Date September 20 - 23, 2020 Hilton Brisbane
05/03/2020 12:15
2020 Aus trala Worksho sia Sulfuric Acid p will off er: — Keynote
A Acid Ma ddress on the Global rket Sulfuric — Informa tive Co-Spo nsor prese — Insightfu nta l — Mainten producing plant pres tions an c e p an e l entations dis — Safety p anel and in cussions cident revie — Co-Spon ws s — Network or exhibits ing opportu nities
Brisbane, Queensland • Australia Sponsored By:
Sulfuric Acid T
O
D
A
Y
Industry’s Premier Event for Networking & Sharing Best Practices™ Register On-Line Today! www.acidworkshop.com PAGE 38
Sulfuric Acid Today • Spring/Summer 2020
Turn-Key Installation For Sulphuric Acid Structured Packing Efficiency FLEXERAMIC® Structured Tower Packing provides plant operators increased absorption efficiency, increased capacity, lower pressure drop and often significantly lower energy costs of operation. This means retrofitting existing packed units with FLEXERAMIC® Structured Tower Packing will improve profitability.
Injection Tower Repair Koch Knight’s proprietary EPOXIGARD HC Injection system provides for fast repair of leaking towers and pump tanks without vessel entry. Our Injection Repair System is a proven success in multiple installations.
Acid Proof Stocked Products • FLEXERAMIC® Ceramic Structured Packing • FLEXISADDLE® Ceramic Random Packing • Ceramic Dome Support • Cross Partition Rings • Ceramic Grid Blocks • KNIGHT-WARE® Acid-Proof Ceramic Brick • DURO™ Acid Brick • PYROFLEX® PTFE DuPly Membrane • Proprietary Mortars • Supplier of Specified Third-Party Equipment > Mist Eliminators > Candles > Distributors
Over 100,000 Cu bic Feet
Ceramic /
of
Plastic
Packing
IN STOC
K!
| Drying Towers | Absorption Towers | | HCR | Storage Tanks | Sumps | Now Manufacturing and Stocking Shop / Field Lining
Membranes and Linings
Brick Installation
East Canton, Ohio (USA) - Baytown, Texas (USA) - Santiago, Chile - Parramatta, Australia - Seoul, Korea - Istanbul, Turkey
Visit us on the web: kochknight.com | Phone: +1 (330) 488-1651
