In a new report, the Global Alliance for Incinerator Alternatives (GAIA) takes aim at chemical methods of plastic recycling, such as pyrolysis and depolymerization. The environmental group says chemical recycling poses environmental hazards and is not technologically feasible at large enough scale to solve the problem of plastic waste.
Many chemical companies promote chemical recycling as an alternative to mechanical recycling. With mechanical recycling, which is based on sorting and washing plastics, attaining properties similar to virgin material is a tall order. In contrast, chemical recycling recovers the original raw materials.
“While such a solution may seem ideal, sound engineering practice and common sense shows that chemical recycling is not the answer to society’s problem of plastic waste,” Andrew Neil Rollinson, who coauthored the report, says in a statement.
Among its critiques, the report notes that chemical recycling requires massive amounts of energy to transform waste into plastics again. A lack of research on chemical recycling allows it to be “portrayed above and well beyond its capabilities,” the report says.
In a statement taking issue with GAIA’s report, the American Chemistry Council, a trade group, cites Argonne National Laboratory findings that fuels produced via plastic pyrolysis require 96% less energy to make than conventional diesel fuel (Fuel, 2017, DOI: 10.1016/j.fuel.2017.04.070).
Since mid-2017, the ACC says, companies have invested $5 billion in plastic recycling, of which 80% has gone to advanced methods like pyrolysis and depolymerization.