9 minute read
Chemical recycling
A PIECE IN THE CIRCULAR ECONOMY PUZZLE
Elisabeth Skoda explores some of the recent innovations in chemical recycling technology and shines a spotlight on collaborative efforts and prospects for the technology.
IN very simple terms, the chemical recycling process breaks down plastics into feedstocks and monomers, enabling the creation of new chemicals and plastics that are equivalent to those made from fossil resources.
CEFIC, the European Chemical Industry Council, has outlined several principles to ensure the scale up and full deployment of chemical recycling, which include collaboration and partnership to boost innovation and investments, increase transparency and develop uniform standards for a mass balance approach, further develop quality standards for sorted or pre-treated plastic waste and use LCA to measure environmental impacts along the life cycle of their products.
To ensure the scale up and full deployment, policymakers are asked to “enable a policy framework that looks beyond the traditional boundaries of regions and members states, and offers an open investment environment and a competitive model, and an open, single market to ensure a continuous supply of plastic waste for the operation of chemical recycling plants.”
A cautious view
In its report “El Dorado of Chemical Recycling - State of play and policy challenges”, NGO Zero Waste Europe takes a closer look at the technology’s potential to solve the plastic waste challenge.
Zero Waste Europe’s report states that the information available about the environmental performance of chemical recycling technologies as a whole is still extremely limited and requires further research.
“Chemical recycling is still in its infancy and most plants in the market are in a pilot stage. The potential roll-out of such technologies at industrial scale can only be expected from 2025-2030 and this is an important factor when planning the transition to a Circular Economy and notably the decarbonisation agenda.”
The report highlights the importance to set up the right policy framework in order to, on the one hand, accommodate chemical recycling as complementary to mechanical recycling and, on the other hand, ensure that the carbon stays in the plastic and is not released into the environment.
“Allowing the conversion of plastic to fuels to be considered chemical recycling risks creating a loophole in EU Climate and Circular Economy legislation. With all its potential, chemical recycling can have a role to play in closing the material loop and moving away from disposal and recovery operations, up the waste hierarchy. Chemical recycling could be a complementary solution to mechanical recycling where the latter proves to be unsuited to materially recover plastic because it is too degraded, contaminated or too complex.”
Great potential for flexible packaging
Dana Mosora, senior consultant for the CEFLEX consortium, sees chemical recycling as a ‘must have’ in the field of flexible packaging.
“We at CEFLEX have run ‘proof of concept’ which demonstrates that flexible packaging can be recycled back into non-food packaging. Yet one problem is hard to tackle: How to make the recycled polymers fit for food packaging, the majority of which is made from flexibles. As we aim to recycle over 55% of it, we need to make sure it will also find its way back into food applications. Additionally, we recognize that there is a limit of how often polyolefins, which make up over 80% of flexible packaging, can be mechanically recycled.”
As chemical recycling is an energy intensive process, the key consideration is how the process scores in total economic and environmental cost compared to the best alternatives.
“Most of the technology providers are in different stages of calls for investment. Indications are that mechanical recycling will cost less and have a lower environmental impact than chemical recycling alternatives of the same PO-based sorted waste. Therefore we believe that the market dynamics and demand for recycled materials of food contact grade will determine whether sorted polyolefins waste is reprocessed by chemical or mechanical recycling,” Ms Mosora says.
She identifies the optimization of the process by the availability of the right waste to enable optimal process and yield.
“We see that CEFLEX can play a role in steering the action for the transformation to happen, such as chemical recycling to meaningfully complement mechanical recycling and thus improving the overall recycling rate of flexible packaging waste in Europe. Both mechanical and chemical recycling will be enabled with the implementation of the ‘Design for a Circular Economy’ guidelines by making more of flexible packaging waste a better infeed material for either recycling type.”
CEFLEX’s goal is to create a full picture of the current and future flows of flexible packaging waste in Europe, showing the input and output materials’ streams potentially available for mechanical and chemical recycling and considering foreseen recycling capacities, requirements and certification to best of our knowledge today.
“Legislation is a critical topic where industries have to work together to enable use of plastic waste as a raw material/feedstock for chemical recycling in addition to mechanical recycling, CEFLEX will collaborate with CEFIC led initiative to build this recognition.”
A closer look at ChemCycling TM
With its ChemCycling TM project, chemical company BASF aims to manufacture products from chemically recycled plastic waste on an industrial scale. The focus lies on plastic waste for which there is no high value recycling process established. Examples of waste plastics which are difficult to recycle mechanically include plastics with residues, multi-layer food packaging or composite plastics used in the automotive and construction industries.
Christian Lach, Lead BASF SE Chemcycling Project, explains the technology, based on a thermochemical process called pyrolysis, which the company is working on with technology partners such as Quantafuel.
“Using high temperatures (300-700°C) and in the absence of oxygen the polymer chains of the plastics are broken down into basic chemicals. The resulting secondary raw material (pyrolysis oil) can partially replace fossil raw materials such as naphtha at the beginning of the value chain in chemical production. The percentage of recycled materials can be allocated to certain products manufactured in the BASF Verbund, using a mass balance approach, and we can offer our customers certified products. These are indistinguishable from products manufactured from fossil feedstock.” Mr Lach points out that the advantage of chemical recycling over energy recovery or landfilling is that the carbon contained in the plastics is permanently preserved and re-used. “Moreover, chemical recycling of mixed plastic waste has significant CO2 savings compared to incineration, including energy use, according to a study by CE Delft.”
BASF has been assessing new raw materials to find out whether they are suitable alternatives for BASF’s processes and products, and according to the company, the results for pyrolysis oil were positive.
“The products made from raw materials obtained via chemical recycling by using a mass-balance-based allocation system for recycled feedstock
exhibit the same quality as products made from fossil resources. ChemCycling™ enables us to offer our customers virgin-like materials based on plastic waste for applications with stringent requirements on quality, efficiency and hygiene,” Mr Lach says.
Despite the promising results, he emphasizes the importance of keeping expectations realistic.
“ Worldwide, chemical recycling has so far played only a minor role in plastic recycling. Its share is less than one percent. Various technological, regulatory and economic issues are still unresolved. The existing processes and technologies for conversion of plastic waste into pyrolysis oil need to be further developed for industrial use to ensure availability of sufficient quantities of the secondary raw material in consistently high quality and at competitive prices.”
Regulatory challenges
Current EU legislation is not opposed to the use of pyrolysis oil produced from plastic waste. However, since chemical recycling barely plays a role in today’s waste management landscape, there are regulatory ambiguities and some hurdles. Without a regulatory push, further development of chemical recycling will be difficult.
“While the legislative framework of the EU builds on a technology-neutral definition of recycling, chemical recycling is not yet recognized as a process which contributes to fulfilling the plastic packaging waste specific recycling targets for material recycling under the Verpackungsgesetz (‘Packaging Regulation’) in Germany. This sends the signal that chemical recycling is
a ‘second class’ option, similar to energy recovery. Acceptance in order to achieve all recycling targets would be an important political signal. Similarly, incentives for recycled content should be applicable to all forms of recycling,” Mr Lach says.
Using water as the ‘agent of change’
ReNew ELP developed its Cat-HTR TM (Catalytic Hydrothermal Reaction) as a form of feedstock recycling, using water as the ‘agent of change’.
A number of other technologies under the chemical recycling umbrella use a pyrolysis model, which sees waste plastic converted through the use of heat in low oxygen conditions,” explains Richard Daley, managing director at ReNew ELP.
“The use of water as the ‘agent of change’ within Cat-HTR TM plays a key role, as it donates hydrogen during the cracking process, meaning no additional hydrogen is required, and end products are stable, with a high yield. It is also relatively insensitive to residual contamination, such as that from organic food matter and paper, removing the need for extensive preprocessing and segregation of the plastic feedstock. Cat-HTR TM can process all plastic types including multi-layered material such as composite films and can tailor outputs based on reactor operating conditions such as residence time and temperature.”
Potential for chemical recycling
He points out that currently, there are a finite number of plastic types that traditional mechanical processes are able to recycle, and highlights flexible packaging, including composite and multi-layer film, and how the new technology can help.
“Over 400,000 tons of these flexible materials are produced every year in the UK alone. The Cat-HTR TM technology is able to convert these materials into feedstock for the production of new, virgin-grade plastic, thus entering these materials into a circular economy. ReNew ELP’s Cat-HTR TM technology uses contaminated household plastics to produce virgin-grade polymer that is suitable for food, health and beauty and pharmaceutical packaging applications.
He echoes the importance of cooperation in order to achieve recycling goals.
“One of our key messages is that the approach to tackle plastic waste and plastic pollution should be a united one. Cat-HTR TM and ReNew ELP are part of a collective group of solutions of companies able to recycle plastic products, which are complementary to traditional mechanic recycling and able to increase the scope of plastic recycling.” n
