Chemical Recycling
Chemical recycling (also referred to as 'non-mechanical' or 'advanced' recycling) offers the opportunity to process plastic waste - both fossil and non-fossil derived - that is difficult to recycle into high-quality, high-value recyclate. The type of plastic input varies based on the technology but can include material that has product residues, additives, fillers, high print coverage, colourants, mixed plastics or multi-material packaging waste. This waste is presently difficult to mechanically recycle into high grade material that can be used in a circular economy. Currently, most of it is sent to energy recovery facilities or landfill.
Chemical recycling technologies will complement both mechanical and purification recycling. It is important to note that, as a complementary technology, chemical recycling
is there to help increase the range of plastics that are recyclable and therefore drive up recycling rates rather than to divert material from mechanical recycling facilities. Any plastic waste material stream that can be mechanically recycled should continue to be recycled via this route as life cycle analysis has shown it has a lower environmental impact.
Chemical recycling is the missing link necessary to achieve a truly circular economy for plastics. By doing so, chemical recycling will reduce carbon emissions by:
• Reducing the reliance on the use of virgin material.
• Diverting waste from energy recovery and landfill.
• Helping to realise wider 'net zero' ambitions.
• Opening up new material streams to recyclers that would otherwise be unrecyclable.
For more information on the current regulations on the safe use of recycled content, please refer to the BPF document Recycled Content Used in Plastic Packaging Applications, which can be downloaded for free.
How do you define ‘chemical recycling’?
Chemical recycling converts polymeric waste by changing its chemical structure to produce substances that are used as products or as raw materials for the manufacture of products (e.g. feedstocks or monomers). Products used as fuels or a means to generate energy are excluded from this definition. In some applications not all the feedstock will be able to be converted back to polymers (e.g. some pyrolytic oils) - however, this definition is intended to exclude material that is solely going for fuel.
Conversion to energy is termed ‘recovery’ – therefore it is not chemical recycling.
‘Chemical recycling’ is an umbrella term covering a number of processes – some of these processes are collectively referred to as ‘feedstock recycling’.
Chemical recycling differs from mechanical recycling, which uses operations to prepare waste polymers for reprocessing without significantly changing the polymeric structure of the material. Chemical recycling, however, breaks down the long hydrocarbon chains in plastics into shorter hydrocarbon fractions or into monomers using chemical, thermal or (chemical/thermal) catalytic processes.
What are the different types of chemical recycling?
Various types of chemical recycling exist including gasification, pyrolysis, hydrothermal treatment and depolymerisation. Feedstock recycling derives its name from the primary output that is produced, namely a petrochemical feedstock. The term ‘feedstock recycling’ is used to differentiate thermal processes that convert the waste plastic into feedstock for a petrochemical plant, from chemical processes that break down the waste product into monomers (i.e. depolymerisation) for further repolymerisation.
Purification (e.g. solvent dissolution), uses solvents to remove additives from the polymers, resulting in a purified polymer as its product. Purification therefore is complementary to both chemical and mechanical recycling. However, it is still a subset of non-mechanical recycling.
The noted chemical recycling processing technologies that make a ‘chemical feedstock’ for onward conversion back into new polymer molecules can be considered recycling because they are maintaining most of the original material-value of the polymer molecules and enabling a circular flow of plastic to take place.
Each process type has a different level of energy demand and output mass yield of useful product. In addition, some are more suited to particular polymers and some are more tolerant of additives and contaminants than others.
Further information on chemical recycling technologies can be found at:
- BPF ‘Chemical Recycling Information hub
- Coalition for Chemical Recycling
- Chemical Recyclers Europe
- Cefic
Are there plans for chemical recycling plants in the UK and Europe?
Many UK-based companies are investing in the development of advanced recycling, with either existing sites or construction imminent. The BPF Chemical Recycling Information Hub has information on facilities being developed in the UK as well as capacity in Europe.
What benefits can chemical recycling deliver?
Chemical recycling can address more complex plastic waste streams that cannot be recycled mechanically into sustainable end-use applications such as food contact or long-life applications.
Chemical recycling can enable the recycling of:
- Plastic waste with organic product residues.
- Mixed plastic waste.
- Plastic waste that has high levels of print coverage and colourants.
- Mixed material structures.
- Waste streams that are currently unrecyclable.
- Thermoformed composites.
The development of chemical recycling will result in higher recycling levels by enabling the recycling of plastic waste that is not currently recycled. Chemical recycling can also increase the number of times a polymer can be recycled, further avoiding waste. It is important that it drives up recycling levels rather than diverts material from existing waste streams.
It could increase the availability of high quality recyclate.
It offers opportunities for the UK to become a leading nation in recycling and will create new employment opportunities at a critical point in time.
How does chemical recycling compare with other forms of recycling and end of life options?
It should be pointed out mechanical and chemical (non-mechanical) recycling are addressing solutions to recycling for different input materials and providing different solutions to address regulatory constraints and therefore end markets. So, comparing these two types of recycling solutions is not entirely relevant, as chemical recycling is complementary to existing mechanical recycling. However, some studies have been conducted on of this relatively new and emerging technology.
The modelling showed that combining mechanical and chemical recycling processes could increase the fraction of plastics kept in circulation - instead of being lost to landfill or incineration - with both economic and environmental benefits for all parties.
A more relevant comparison for chemical recycling is to compare it with waste disposal options such as Energy from Waste as it is looking to divert material from these facilities. A report commissioned by CEFIC called ‘Chemical Recycling: Greenhouse gas emission reduction potential of an emerging waste management route’ concluded that “chemical recycling can avoid the incineration of plastics and corresponding end-of-life GHG emission, with favourable overall GHG emissions balance."[1] This report looked at a number of studies, including a report by CE Delft ‘Exploration chemical recycling – Extended summary’.[2] This looked at gasification, pyrolysis and hydropyrolysis and in all cases chemical recycling compares favourably to incineration. A Sphera report on behalf of BASF found a specific example that pyrolysis “of mixed plastic waste emits 50% less CO2 than incineration of mixed plastic waste.”[3] It is therefore clear that chemical recycling will have a significant role in reducing carbon emissions.
The BPF Chemical Recycling Information Hub has a list of LCAs on chemical recycling.
What will capacity be like by 2030?
The BPF’s Recycling Roadmap provides a forecast for the end destination of plastic waste in the UK by 2030. The forecast shows 7% of material going for non-mechanical recycling (300 kT). Although this is less than is predicted by some other reports, it represents a 60-fold increase compared to 2020.
Non-mechanical recycling split by sector in 2030
Mass balance
Mass balance is the practical calculation method needed for chemical recycling. It needs to be permitted within the UK Plastic Packaging Tax for the chemical recycling industry to develop. This is because, unlike other forms of recycling, you cannot physically trace the recycled material through the facility. It is a proven method already used in other industries such as ‘fairtrade’ and ‘renewable energy’. It ensures that the input recycled material into a facility matches the output recycled material (with losses removed) and a certified paper trial allows input recycled material to be allocated to an output recycled product.
There are different methods to allocate the material to an output product. The chosen method affects the amount of output material there is available to be allocated to a product and therefore the viability of chemical recycling. The BPF supports a ‘fuel exempt’ method, which means the percentage of output material going for fuel and losses are removed from the input material before it is allocated to an output.
More information on mass balance is available in the BPF Chemical Recycling Information Hub.
In conclusion…
Chemical recycling needs a level playing field to enable it to contribute alongside mechanical recycling. At present, barriers exist that need addressing.
For chemical recycling to reach its potential, this requires:
- Mass balance to be accepted within the Plastic Packaging Tax, with a ‘fuel exempt’ allocation method.
- Chemical recycling facilities to be able to achieve ‘end of waste’ status for their output material.
- No delays in permitting the construction of new chemical recycling facilities.
- Chemical recycling to be recognised by Defra as a means of recycling and agreement by the Environment Agency (EA) that Chemical Recycling is eligible for PRNs (at present this can only be on a case-by-case basis, which is not sustainable).
- Public sector support and investment to accelerate commercial scale development of the technology.
- Access to adequate plastic waste feedstock. This includes the need for a kerbside collection of films. At present, much of the feedstock required for chemical recycling is not collected for recycling from consumer households in the UK, therefore it needs to be extracted at source or prior to disposal).
- In common with mechanical recycling, improved quality standards for pre-sorted plastic waste to be pursued in the UK and harmonised with other countries. End of waste approval for the products generated from chemical recycling, granted in a timely basis.
Sources and further information
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CEFIC (2020). Chemical Recycling: Greenhouse gas emission reduction potential of an emerging waste management route. Pg. 18. Downloadable at: https://cefic.org/media-corner/newsroom/new-study-confirms-role-for-chemical-recycling-in-reducing-greenhouse-gas-emissions/
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CE Delft (2020) ‘Exploration chemical recycling – Extended summary’ cedelft.eu/wp-content/uploads/sites/2/2021/03/CE_Delft_2P22_Exploration_chemical_recycling_Extended_summary.pdf
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BASF (2020). Life cycle assessment (LCA) for ChemCyclingTM. Available: www.basf.com/global/en/who-we-are/sustainability/we-drive-sustainable-solutions/circular-economy/mass-balance-approach/chemcycling/lca-for-chemcycling.html. Last accessed 4 Feb 2021.
Originally published June 2019
Last reviewed and updated July 2024
