Review of catalytic pyrolysis of biomass for bio-oil

Pyrolysis utilizes biomass to produce a liquid product bio-oil which is widely used as a potential energy source and a low-cost feedstock for chemical production. Considerable efforts have been made to convert biomass to bio-oil since the oil crisis in mid-1970s. This review focuses on the recent developments in catalysts used in pyrlysis of biomass for bio-oil production. In this review, 5 types of catalysts such as metal oxide, molecular sieve, mineral, transition metal and others, have been given. Molecular sieves, such as HZSM-5, ZSM-5, MCM-41, SBA-15, HUSY, REY and their modified catalysts are most widely used in biomass catalytic pyrolysis process. The effects of catalysts on bio-oil yields, quality, composition, stability etc. are also discussed. Although catalysts in pyrolysis of biomass produce markedly influences on bio-oil products, the variety of catalyst types and properties make generalizations difficult to define, in regard to trying to critically analyze the literature.