Microwave-assisted pyrolysis of waste plastics for their resource reuse: A technical review

Rapidly increasing plastics have been used and finally become wastes, resulting in increasing pressures to the environment. Microwave-assisted pyrolysis is a promising technology for converting organic wastes as waste plastics into value-added products. At present, many works on microwave-assisted pyrolysis of plastics have been published, but the achievements, challenges, and future directions of microwave-assisted pyrolysis of waste plastics have not been well summarized and discussed. In this work, the principle of microwave-assisted pyrolysis technology is introduced. Then, the progress of its application to recover useful products from plastics is reviewed and discussed in terms of key parameters including microwave power, pyrolysis temperature, reaction time, types of catalyst, microwave absorbents and feedstock mixing ratio. Especially, the yields and properties of the produced oil, gas and char are correlated with the process parameters. Finally, the existing challenges and prospects of disposal/reuse of waste plastics by microwave-assisted pyrolysis technology are discussed.