渗析电解法提浓甲酸的研究

Concentration of formic acid by electro-electrodialysis

针对甲酸生产过程中能耗较高的不足 ,提出了用渗析电解法进行浓缩分离的方法 ,并利用实验验证了该方法的可行性 .通过实验系统地研究了在渗析电解过程中 ,甲酸浓度、电流强度、操作时间及膜两侧浓差等因素对于表观电流效率和浓缩比的影响 .结果表明 ,渗析电解法提浓甲酸在实验研究范围内均具有较高的表观电流效率 ,在高浓度条件下 ,表观电流效率可以大于 10 0 % .随着电流强度的增加 ,浓缩比会随之增加 ,但表观电流效率先随电流强度的增加而增加 ,当电流强度增加到一定值后 ,表观电流效率会随之有所下降 .膜两侧的浓差的增大会使得表观电流效率下降 .但如果操作时间足够长 ,用电渗法可以达到较高的浓缩比 ,且具有较高的表观电流效率 .

In order to reduce the energy consumption in the process of formic acid production,concentration of formic acid by electro electrodialysis was studied.The experimental results indicate that electro electrodialysis was a promising method to concentrate formic acid solution.The apparent current efficiency of this process was high.In the high concentration formic acid system,since the molecule association took place, the apparent current efficient was more than 100%. The apparent current efficiency for low concentration system would be up to 80%～95%.In general,the apparent current efficiency was increased with the electric current in low current density.After the current density reached a certain value,the apparent current efficiency would begin to drop.If the difference of the fromic acid concentration at both sides of membrane was increased,the apparent efficiency would be decreased.