Vast quantities of mixed low-grade plastics - not viable for recycling - are shipped overseas by the UK each year. Around 340,000 tonnes each year: wasting an energy-rich resource, creating more landfill waste and potential threats to ocean habitats.
Work led by Dr Stuart Wagland has demonstrated how wastes can be used as fuels in combustion processes, or used as feedstock for producing energy-rich gases, liquid fuels and chemicals.
“Thermal processing of wastes under gasification or pyrolysis conditions offers a more flexible approach than combustion,” explains Dr Wagland. “This kind of thermal treatment plant would produce regular supplies of high-quality products usable for heating and power - which even could be used to run the fleet of vehicles collecting the waste plastics.
“Even greater value is contained in the oil, with a range of uses in the petrochemical industries, and as aviation and HGV fuel. CO2 emissions from this kind of process would be significantly lower than using virgin materials like crude oil.”
Key Facts
Testing has included the use of a small-scale thermochemical plant using plastic-rich waste materials as a feedstock for a one megawatt pyrolysis facility, processing wastes and producing high-value liquid fuels and chemical products. The research is part of an ongoing effort to demonstrate the viability of localised, small-scale facilities - what would be the heart of a community-based circular model, dealing with the average mix of waste from households and industry, as well as generating energy and fuels for local services.
