摘要
Liquid phase oxidation of toluene is an environmental benign route for the production of benzoic acid.In a φ48mm bubble column reactor,the commercial process of toluene liquid phase oxidation was conducted with Co(CH3COO)2.4H2O as catalyst.The Co2+ concentration [Co2+] was determined by extraction spectrophotometry and hereby the Co3+ concentration [Co3+] was obtained by mass balance.The results showed that [Co3+] reached the maximum at about 25-30min.[Co3+] increased with increasing Co catalyst amount at total Co concentration<150 mg.L-1 of toluene.The conversion of toluene,yield and selectivity of benzoic acid increased with the increasing [Co3+/Co2+] max.A high [Co3+] and a high [Co3+]/[Co2+] ratio are beneficial to the reaction.
Liquid phase oxidation of toluene is an environmental benign route for the production of benzoic acid. In a Ф48mm bubble column reactor, the commercial process of toluene liquid phase oxidation was conducted with Co（CH3COO）2·4H2O as catalyst. The Co^2＋ concentration [Co^2＋] was determined by extraction spectrophotometry and hereby the Co^3＋ concentration [Co^3＋] was obtained by mass balance. The results showed that [Co^3＋] reached the maximum at about 25-30 min. [Co^3＋] increased with increasing Co catalyst amount at total Co concentration 〈150mg·L^-1 of toluene. The conversion of toluene, yield and selectivity of benzoic acid increased with the increasing [Co^3＋/Co^2＋]max. A high [Co^3＋] and a high [Co^3＋]/[Co^2＋] ratio are beneficial to the reaction.
基金
Supported by the National Natural Science Foundation of China （20576081, 20736009） and the Ph.D. Programs Foundation of Ministry of Education of China （20070610128）.
