Since 1980, plastic waste generation had increased exponentially due to its wide application in many sectors and reached 369 million tons globally in 2019. However, only 9% of this plastic waste was recycled and 12% was incinerated, while the remaining were discarded, posing pollution problems. As plastics are largely derived from fossil fuels, the valorizing of these waste plastics into value-added fuels or chemicals could help tackle the huge plastic waste deposition, contribute to a circular economy, and reduce reliance on the scarce hydrocarbon resource. This could be achieved with chemical recycling, such as pyrolysis, to fragment these waste plastics into simple organic compounds, which is a promising process to convert plastic waste to fuel. Hence, in this chapter, the parameters of the pyrolysis process and the physicochemical characteristics of its resulting pyrolysis oil are discussed. Additionally, imminent chemical recycling technologies that were recent developed will also be introduced such as hydrogenolysis, microwave-assisted oxidative degradation, and photocatalytic degradation.
Circularity of Plastics: Sustainability, Emerging Materials, and Valorization of Waste Plastic, Volume 1, 1 January 2023,