Pyrolysis of plastic waste: Opportunities and challenges

Abstract

With current low recycling rates and exponentially increasing production of plastics there is an increase in plastic material wastage, and thus new technologies are needed for waste refining. Presently in Europe, only about 10% of plastic waste is recycled, most of which is achieved through mechanical recycling. Chemical recycling methods like pyrolysis could significantly increase these recycling rates, as it can utilize mixtures of waste plastics unlike mechanical recycling. It can also be used to treat waste of many novel materials, such as composites, especially in the emerging phase when the volumes of the new materials in markets are low making separate collection of waste not a cost-efficient option. Pyrolysis offers an environmentally sound alternative to incineration and inefficient landfilling. Currently, main challenges for pyrolysis of plastic waste are unavailability and inconsistent quality of feedstock, inefficient and hence costly sorting, non-existent markets citing lack for standardized products, and unclear regulations around plastic waste management. Possible solutions could include tight cooperation between feedstock providers and converters for securing steady quantity and quality of feedstock. Advanced pre-treatment would provide the basis for cost-effective recycling. The classification of pyrolysis liquid as a product instead of waste is needed, and the REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) registration should be carried out to standardise the liquid oil as a product. In addition, sustainability impacts need to be clearly positive.