Pyrolysis of waste plastics for alternative fuel: a review of key factors

Abstract

Plastic is a threat to the environment since it does not biodegrade, but it also has the potential to become a substantial resource to produce alternative energy sources, creating a multibillion-dollar untapped market. Every year, millions of tons of plastic are produced, resulting in a significant rise in plastic waste, which causes ecological and environmental problems. According to estimates, only around 10% of this waste plastic is now recycled. Plastic waste may be handled in two ways: recycling or converting it into energy. The first alternative, recycling, has several challenges, including the need for labor-intensive processes and concerns about water pollution, which may threaten its long-term sustainability. As a result, the second technique for turning waste plastic into energy has been developed, enhanced, and extensively researched. Pyrolysis is a technique that involves heating plastics at temperatures ranging from 455–700 °C without oxygen. This process yields high-calorific fuel that can be utilized as an alternative fuel. This study explores the thermal and catalytic cracking processes involved in waste plastic pyrolysis, focusing on crucial factors such as temperature, time, feedstock, reactor type, and catalyst that impact results such as oil production, gases, and heat. Furthermore, the study investigates the properties of the liquid oil produced and offers suggestions for enhancing the liquid fuel yield for each kind of plastic.