Research Progress on Gas Generation from Waste Plastics Through Pyrolysis

Plastic pyrolysis technology, as an efficient and stable path for chemical recycling of waste plastics, alleviates current energy pressures and solves the problem of continuous accumulation of waste plastics in the environment. At present, the vast majority of research on plastic pyrolysis is focused on how to improve the yield and quality of liquid fuels, while there is generally little research on the gases generated by plastic pyrolysis. However, gases such as H₂, CH_4, and light hydrocarbons generated during pyrolysis also have high utilization value, and have very considerable application prospects in chemical, aerospace, and metallurgical fields. In addition, compared with the separation difficulties of liquid products, the treatment of gas products is easier and more conducive to subsequent utilization. This article discusses and analyzes the yield and composition of gases generated by plastic in three different pyrolysis methods: direct pyrolysis, catalytic pyrolysis, and microwave pyrolysis. Compared to traditional direct pyrolysis, catalytic pyrolysis and microwave pyrolysis can treat plastic waste more efficiently and energy-efficient, and have higher gas yields. This article also discusses various factors such as temperature that influence the formation of gas products and their importance. Finally, the challenges faced are proposed, aiming to provide reference and direction for future research on improving the yield of gas generated by plastic pyrolysis.