Abstract: At present, the research on synthesis of m-methyl benzoic acid is mainly limited to the intermittent reaction process of the oxidation vessel, and there are few reports on the continuous flow reaction process. In response to this problem, a continuous flow process for the synthesis of m-methyl benzoic acid in liquid-phase oxidation in pulsed hybrid microchannel reactors was proposed. Using m-xylene as the raw material, peracetic acid as the oxidant, cobalt acetate and sodium bromide as catalysts. Through the inspection of the reaction material ratio, the amount of catalyst, the reaction residence time, the reaction temperature and the amount of solvent, etc, the optimum process conditions were obtained. When n(m-xylene):n(peracetic acid):n(cobalt acetate):n(sodium bromide):n(acetic acid)=1:4:0.015:0.02:5, reaction temperature at 120℃, the residence time at 15min, the reaction performance was the best. The results showed that this process takes full advantage of the excellent mass and heat transfer characteristics of the microchannel continuous flow reactor, greatly shortens the reaction time, increases the reaction rate, expands the selection range of the process conditions, increases the safety factor and realizes the effective control of the oxidation reaction process.

Key words: microchannel reactor, continuous flow process, oxidation, mass transfer, heat transfer

摘要： 目前，对合成间甲基苯甲酸的研究主要局限于氧化釜的间歇反应工艺，对连续流反应工艺少有报道。针对这一问题，本文提出了在脉冲混合结构微通道反应器中液相氧化合成间甲基苯甲酸的连续流工艺。采用间二甲苯为原料，过氧乙酸为氧化剂，乙酸钴和溴化钠为催化剂，通过对反应物料比、催化剂的用量、反应停留时间、反应温度、溶剂用量等条件的考察，获得最佳工艺条件。得出当n（间二甲苯）∶n（过氧乙酸）∶n（乙酸钴）∶n（溴化钠）∶n（乙酸）=1∶4∶0.015∶0.02∶5、反应温度120℃、反应停留时间15min时，反应效果最佳。研究结果表明：此工艺充分利用微通道连续流反应器优良的传质传热特点，大大缩短了反应时间，提高了反应速率，扩大工艺条件选择区间，增加了安全系数，实现对氧化反应过程的有效控制。

关键词: 微通道反应器, 连续流, 氧化, 传质, 传热