Catalytic hydrotreatment of lignin-derived pyrolysis bio-oils using Cu/gamma-Al2O3 catalyst: Reaction network development and kinetic study of anisole upgrading

摘要

Kinetic of anisole upgrading as a model compound of lignin-derived pyrolysis bio-oil to jet-grade fuels via catalytic hydrotreatment process has been investigated. Hydrodeoxygenation (HDO) process has been performed in a fixed-bed tubular reactor at operating temperature of 573 to 723 K, space velocity of 3 to 120 (anisole weight)/(catalyst weight x h), and hydrogen pressure of 8 bar. Benzene formation through demethoxylation reaction of anisole was identified to be the primary reaction route in contrast to demethylation, alkylation, and transalkylation reaction classes, which are more dominant for synthesized Cu/gamma-Al2O3 catalyst. Benzene is formed as the primary product through HDO of phenol assigning the lowest activation energy of 1.18 kJ/mol. Toluene and hexamethylbenzene are derived from alkylation reaction of benzene. Phenol is produced rapidly with highest selectivity among different products as the primary product via hydrogenolysis reaction. According to the kinetic data, phenol formation possesses the highest activation energy of about 59 kJ/mol. Moreover, 2-methylphenol and other phenol-derivatives are produced from alkylation and transalkylation reactions of phenol. The developed comprehensive quantitative reaction network for anisole catalytic hydrotreatment over Cu/gamma-Al2O3 is in appropriate agreement with previous studies.