联用反应动力学、电荷衡算和物料衡算建立阴极冷却固定床草酸电合成乙醛酸反应器模型方程.针对反应器连续化操作过程,用正交配置法数值求解该模型方程.结果表明,在连续化操作的反应初期,反应液中的乙醛酸能够较快地达到预定浓度,但继续增加反应器的长度,反应的效果不明显.该模型还模拟了分段温控和部分回流对反应的影响.结果表明,分段温控和部分回流均可较好地提高乙醛酸在阴极液中的浓度.计算结果与试验操作基本相符.该结果对阴极冷却固定床草酸电合成乙醛酸的连续化操作工艺和反应器的优化具有重要的参考意义.

Oxalic acid electrochemical reduction has been suggested as an important technology to produce glyoxylic acid;the packed-bed electrochemical reactor with cooled cathode(PERCC)has been proposed to solve the problem of lower space-time-yield that appeared in the parallel electrode reactor.Based on the mass balance equations,charge balance equations and kinetics equations of the system,a two-dimensional reactor model was established to describe the continuous operation process for producing glyoxylic acid from oxalic acid by PERCC.Using the orthogonal collocation method,the model equations could be numerically solved,and the glyoxylic concentration along the reactor length could be simulated.The modeling results indicated that the glyoxylic concentration increased quickly at the early stage of the reaction,but weared off following the further increase of the reactor length.The effects of a varied operating temperature and partial reflux on the concentration of glyoxylic acid were investigated by the model,indicating that both the approaches could effectively improve the glyoxylic acid concentration in the catholyte for a continuous operation process.The experimental results from a continuous operation process were generally in agreement with the calculated values of the model.