Review on the catalytic pyrolysis of waste oil for the production of renewable hydrocarbon fuels

The deterioration of environment and the depletion of fossil fuels have inspired the exploration for alternative fuels based on renewable raw materials. This review presented the catalytic pyrolysis of waste oil for producing renewable hydrocarbon fuels. After the discussion of various process parameters, including waste oil characteristics, microwave absorbents, co-pyrolysis technology, catalysts, and reactor types, the best conditions for improving the yield and quality of hydrocarbon fuels were obtained. The advantages and limitations of microwave-assisted pyrolysis and conventional electric heating were discussed. Microwave-assisted pyrolysis is a relatively new technology compared with traditional electric heating pyrolysis, which has great development potential. In the future, the catalysts with low pressure drop and coking rate need to be developed and their microwave absorption characteristics in microwave-assisted pyrolysis must be fully investigated. Simultaneously, a continuous microwave-assisted pyrolysis system needs to be constructed to achieve the large-scale production of renewable hydrocarbon fuels from waste oil.