Ex-situ catalytic microwave pyrolysis of lignin over Co/ZSM-5 to upgrade bio-oil

The present study aims to produce bio-fuel from lignin via catalytic upgrading of vapors from lignin microwave pyrolysis. The effects of cobalt modified ZSM-5 catalysts on products yield and chemical selectivity of bio-oils were investigated. A central composite experimental design (CCD) was used to optimize the reaction conditions for bio-fuel production. The effects of the reaction temperature and ratio of catalyst to lignin on products (bio-oil, gas and volatiles) yield distribution and chemical composition of bio-oil were investigated. Response surface analysis indicated that the obtained models were able to predict the products yield distribution and the major chemical compound distribution of the bio-oil. GC/MS analysis revealed that the main chemical compounds were ketones, furans, phenols and guaiacols, which accounted for more than 85% in the detected bio-oil. GC analysis showed that the major components of the gas were H2 and CO (about 60%).