The separation of the binary mixture formic acid–water is difficult by conventional distillation since it forms maximum boiling azeotrope at atmospheric pressure. The separation by altering the column pressure is possible if the pressure has a considerable effect on the azeotropic composition. The previous studies of vapor–liquid equilibrium of binary system formic acid–water have shown that the azeotrope is sensitive to pressure. This work aims to study the effect of the concentration of formic acid in the binary mixture formic acid–water on the ease of separation using two distillation columns operating at different pressures, which are determined by the composition variation of the azeotrope with pressure. The process consists of two-column, the first column operating at pressure of 1.96 bar to recover water and the second column operating at pressure of 0.267 bar to recover formic acid. The best operating parameters have been determined to get the high recovery ratio of formic acid.

传统的蒸馏方法很难分离甲酸-水的二元混合物，因为它在大气压下会形成最大沸腾的共沸物。如果压力对共沸组合物有显着影响，则可以通过改变柱压进行分离。先前对二元体系甲酸-水的汽-液平衡的研究表明，共沸物对压力敏感。这项工作的目的是研究使用两个在不同压力下运行的蒸馏塔对二元混合物甲酸-水的甲酸浓度对分离的难易程度的影响，这是由共沸物随压力变化而确定的。该过程由两塔组成，第一塔在1的压力下运行。96巴以回收水，第二塔在0.267巴的压力下操作以回收甲酸。确定了最佳的操作参数以获得较高的甲酸回收率。