A review on role of process parameters on pyrolysis of biomass and plastics: Present scope and future opportunities in conventional and microwave-assisted pyrolysis technologies

Pyrolysis is one of the thermochemical conversion platforms for biomass and plastics into value-added product resources. The products formation significantly varied with feedstock composition, pyrolysis parameters, and heating source. Hence, the objectives of this review article are to understand the role of type of feedstock, heating rate, reaction temperature, residence time, feedstock particle size, and type of pyrolysis reactor. In addition, the upgradation of bio-oil using physical and catalytic approaches has been analyzed. Co-pyrolysis and catalytic co-pyrolysis which promote the product properties through synergy are also investigated. The role of microwave heating with the help of a susceptor to promote product synthesis is discussed. The metal oxide and zeolite catalysts' role in the formation mechanism of hydrocarbons and oxygenates are studied. For the future scope, the studies related to pyrolysis-combustion combination, microwave hybrid heating, and continuous catalytic co-pyrolysis are promising approaches. To this end, this review bridges the research gap in the domain of pyrolysis process parameters, and waste valorization using microwave-assisted pyrolysis, co-pyrolysis, and catalytic co-pyrolysis technologies. Moreover, this review would further provide the way for the current issues related to effective biomass and plastic waste utilization. (c) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.

Automated summary

Pyrolysis is a thermochemical conversion platform that converts biomass and plastics into value-added products. This review focuses on understanding the role of different parameters, such as feedstock composition, heating rate, reaction temperature, residence time, feedstock particle size, and type of pyrolysis reactor. It also analyzes the upgradation of bio-oil using physical and catalytic approaches, as well as the synergistic effects of co-pyrolysis and catalytic co-pyrolysis. The review discusses the use of microwave heating and the role of metal oxide and zeolite catalysts in hydrocarbon and oxygenate formation. Future promising approaches include pyrolysis-combustion combination, microwave hybrid heating, and continuous catalytic co-pyrolysis. This review fills the research gap in understanding pyrolysis process parameters and waste valorization using microwave-assisted pyrolysis, co-pyrolysis, and catalytic co-pyrolysis technologies. It also provides insights into the effective utilization of biomass and plastic waste.