In a new report, the Global Alliance for Incinerator Alternatives (GAIA) takes aim at chemical recycling methods for plastic recycling, such as pyrolysis and depolymerization, which have been embraced by the chemical and oil industries. The environmental group says chemical recycling poses environmental hazards and is not technologically feasible at a large enough scale to solve the plastic waste problem.
Many chemical companies have been promoting chemical recycling as an alternative to mechanical recycling. For mechanical recycling, which is based on sorting and washing plastics, attaining purity and properties similar to virgin materials is a tall order. Chemical recycling schemes, in contrast, recover the original raw materials.
“While such a solution may seem ideal, sound engineering practice or common sense shows that chemical recycling is not the answer to society’s problem of plastic waste,” Andrew Neil Rollinson, who coauthored the report, said in a statement. “It represents a dangerous distraction from the need for governments to ban single-use and unnecessary plastic, while simultaneously locking society into a ‘business as usual’ future of more oil and gas consumption.”
Among its critiques of chemical recycling, the report says pyrolysis can produce dangerous by-products such as toxic polycyclic aromatic hydrocarbons. The chemical recycling processes, the report points out, also require massive amounts of energy to transform waste into plastics again. The report says that a lack of research on chemical recycling allows it to be “portrayed above and well beyond its capabilities.”
Keith Christman, managing director of plastics markets for the American Chemistry Council, a US industry trade group, put out a statement following release of the GAIA report that cites an Argonne National Laboratory study that said that fuels produced via plastic pyrolysis are 96% less energy intensive to make than conventionally produced diesel fuel (Fuel, 2017, DOI: 10.1016/j.fuel.2017.04.070).
Christman also claimed that since mid-2017, companies have invested $5 billion in recycling, of which 80% was in advanced recycling.