Influences of the [Co^2＋]/[Co^3＋] Ratio on the Process of Liquid-phase Oxidation of Toluene by Air

• Published in: Chinese journal of chemical engineering Vol. 17; no. 4; pp. 613 - 617
• Main Author: 唐盛伟 沈伟 梁斌
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 2009
• Subjects: Benzoic acid; Catalysts; Chemical engineering; cobaltous acetate; Conversion; Extraction; Liquid phase oxidation; Reactors; Toluene; 催化剂用量; 液相氧化; 苯氧化; 萃取光度法; 鼓泡反应器; benzoic acid; liquid-phase oxidation; toluene; cobaltous acetate
• ISSN: 1004-9541; 2210-321X
• DOI: 10.1016/S1004-9541(08)60252-9

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.