Chemical recycling: the unremarkable and oversold
Did not live up to the hype
In a zero waste society, we want to use our resources in the best possible way. For materials and products that are not yet realistic for waste prevention and reuse—whether technically, legislatively or financially—we turn to recycling. However, things here may get a little complicated. Different recycling technologies have completely different effects on the environment and climate.
Recently, the so-called "chemical recycling" has attracted much attention. The term currently refers to the conversion of plastic waste into its basic building blocks, usually in the form of oil, which can then be used as a raw material for making new plastics. These technologies include pyrolysis (using high energy and almost no oxygen to decompose plastics) and gasification. These technologies have existed for many years, but have not succeeded in expanding the scale of their plastic to plastic process. However, people often claim that they are on the cusp of revolutionizing plastic recycling.
In fact, compared with traditional recycling, "chemical recycling" technology requires a lot of energy. They also need clean, homogeneous waste streams to produce high-quality products-in terms of waste materials, this may compete with more sustainable recycling technologies (such as mechanical recycling).
The new report reveals everything
Although the limitations and risks of "chemical recycling" have become more and more clear to many environmental organizations, the CHEM Trust organization and consulting firm Eunomia recently reviewed the performance and impact of different "chemical recycling" technologies in their environment. , Detailed description of the distribution of land. Report on chemical recycling: the status quo. The report also highlighted concerns about hazardous chemicals in these processes. Facts have proved that we really don't know enough. Although some technologies may be expected to complement traditional recycling, we must be careful not to "lock in" the increased environmental impact in the long term. Countries that have invested heavily in waste incineration for power generation have adopted a similar approach."
As described by Dr. Michael Warhurst, Executive Director of CHEM Trust:
"In the context of a clean and safe circular economy, as advocated by the CHEM Trust, chemical recycling seems to be oversold [...] The end result may still be contaminated by hazardous chemicals, and the economic viability of many of these technologies is doubtful ."
Are we there yet?
In evaluating these three types of technologies, the report investigated their technical and commercial maturity. Although the report covers more details, in short, solvent purification is found to be most promising in very niche applications-such as consumer electronics packaging or insulating boards with traditional flame retardants that cannot be mechanically recycled. However, this technology inherently degrades materials, does not allow unlimited recycling, and is unlikely to compete with mechanical recycling due to high energy requirements.
It is said that chemical depolymerization can produce cleaner products and is expected to be used in PET/polyester. However, high yields seem to be possible only when clean and homogeneous waste streams are used, and these parts can already be mechanically recycled. For example, it is believed that the chemical depolymerization of PET bottles is unlikely to compete with mechanical recycling, especially when they are part of the Deposit Refund System (DRS).
Although pyrolysis (such as pyrolysis) has not been commercially proven as a way to produce new plastic raw materials, it has become a more mature fuel production method. Remember: because plastic is a fossil-derived material, converting plastic into fuel will release the fossil carbon embedded in the material into the atmosphere! Facts have proved that compared with traditional recycling, the use of pyrolysis of plastic waste to produce raw materials for new plastics also brings material and carbon losses. The produced pyrolysis oil either needs to go through several steps of purification, or it is mixed with raw fossil fuels to produce materials that can be used in plastic production before passing through a cracking unit; it generates potentially hazardous waste. Although the theory that pyrolysis can be used to treat dirty and mixed plastic waste is theoretically correct, it will result in low production and output, and it is likely that the pollution will be too serious to meet the requirements of the cracker. Therefore, any advanced plastic waste sorting and cleaning required for mechanical recycling may also require pyrolysis.
Since the biggest selling point of chemical recycling is the ability to handle all types of plastics, this trade-off may reduce the motivation to further explore thermal depolymerization as a sustainable plastic recycling method. However, the report recognizes potential applications for specific waste streams that are not attractive to machinery recyclers, such as mixed but clean polyolefins such as films.
Can we bear the environmental impact?
Of course, recycling plastic is good. However, it is not very good to clear plastic garbage dumps through methods that may pollute our air and environment. Our atmosphere does not require additional greenhouse gas emissions, because plastic waste has shifted from mechanical recycling to energy-intensive technologies. Even for technologies that seem likely to generate specific waste streams, this should not hinder efforts to reduce or prevent such waste.
If you believe in this industry, chemical recycling may separate dangerous chemicals and substances so that the recycled plastic can even be used safely in contact with food. However, research by CHEM Trust and Eunomia found that there is insufficient information about the nature, quantity and toxicity of the solvents and chemicals used, as well as the fate of waste and by-products formed by the process itself. In reviewing some existing life cycle assessments, the author pointed out that energy use is the most important aspect of considering environmental impacts, and emphasized the lack of consistency and transparency in assessing the output of various technologies.
An important observation is that "even when compared with relatively poor performance mechanical recycling schemes, the current pyrolysis oil monomer process seems too energy-intensive to compete."An overwhelming finding of the report is the need to improve transparency and evidence of the performance and feasibility of these technologies, especially considering the many unproven claims about their sustainability. It is not clear whether this is due to lack of knowledge or lack of willingness to share unfavorable information. Until then, caution is the key. "Investment should be left to organizations that freely participate to improve their understanding of these missing elements."
As from an environmental point of view, chemical recycling and recycling seem unlikely to achieve good results, the EU should take preventive measures and clarify their position on these technologies, believing that these technologies are inferior to mechanical recycling. In the case where the carbon footprint produced by the process is higher than that of the original plastic production, their use should be particularly restricted. If not, we just replaced the plastic waste problem with the climate change problem. The EU classification will be an important opportunity to encourage investment and support the use of mechanically recycled secondary materials to make plastics, rather than high-energy technologies. Several recent initiatives-including taxonomy, sustainable chemical development strategy and new circular economy action plan-all mention chemical recycling and its impact on the environment. Therefore, before further developing a legislative framework to encourage these technologies, the European Commission should support a more independent, transparent and comprehensive assessment of the environmental and climate impacts of chemical recycling based on major data sources.
Want to learn more about the status of chemical recycling in Europe?
Read the executive summary or full report of the CHEM Trust and Eunomia report "Status: Chemical Recycling". Explore our ten points of focus on existing chemical recycling life cycle assessments. Learn about our alliance with Rethink Plastic, especially the joint statement of ECOS, EEB and HCWH, which outlines the key steps for effective chemical recycling legislation in the EU. Learn more about our research on this topic: El Dorado of Chemical Recycling, status quo and policy challenges. Read Zoe Casey's blog to learn why chemical recycling cannot solve the plastic crisis.
About the latest post
Joint Press Release: The Broad Alliance urges the European Parliament to protect consumers from dangerous or illegal products sold through Amazon and AliExpress' online marketplace. -15/07/2021 "Chemical recycling" design stifles upstream innovation-12/07/2021 Harmful chemicals in food packaging put our health at risk-29/06/2021