Thermal and catalytic cracking of plastic waste: a review

Nowadays, plastic waste (PW) disposal is one of the serious global problems facing humanity and ecosystem balance. As the population increases continuously, the fuel market has been growing so the demand for plastic is also increased to cover the growing levels of consumption that leads to a serious environmental crisis by the PW accumulation. Therefore, recycling processes take place to clean the environment from these accumulated quantities of waste. Many studies accounted that the most suitable chemical recycling technique is pyrolysis which means conversion of the PW into valuable products in presence of heat. This review explained chemical structures, uses, recycling by thermal and catalytic pyrolysis of the plastic materials and discussed a comparison between two processes above. Moreover, investigation effects of the operating conditions such as temperature, pressure, residence time, and catalyst presence on the product distribution. Also, the reaction mechanism details of the process and work of previous researchers were addressed in this paper.