催化精馏塔内甲酸甲酯水解制甲酸的研究

在催化精馏塔内以压制的强酸性阳离子交换树脂为催化剂填料对甲酸甲酯水解制甲酸进行了实验研究.在全回流操作条件下,通过改变操作参数获得了高于90%的水解转化率.考虑到反应过程中水的阻碍作用,根据实验结果提出了可用于催化精馏过程的动力学方程并建立了基于平衡级理论的反应与分离耦合的数学模型.通过设定进料水酯摩尔比、回流与进料比、反应段与分离段理论级数等参数获得了水解过程的仿真结果,并提出了较佳的工艺操作条件.研究表明:仿真结果与实测数据相吻合;通过改变操作条件可调整反应段内水与甲酸甲酯的浓度,提高水解速度;增加反应段的高度比增加分离段的高度更有利;产品甲醇和甲酸在催化精馏塔内能够完全分离,反应段两端反应速度高于中间段的反应速度.

Study on Hydrolysis of Methyl Formate into Formic Acid in a Catalytic Distillation Column

Hydrolysis of methyl formate to form formic acid was studied experimentally by using strong-acid cation-exchange resin as catalyst and packing in a catalytic distillation column. The hydrolysis conversion rate over 90% was obtained via changing operation parameters of the total-reflux operation. Taking the inhibition of the water to the reaction into account and based on the revised kinetic equation and equilibrium-stage theory, a mathematic model coupling the catalytic reaction with distillation separation was proposed. The process simulations were carried out by changing different operation parameters, such as the feed molar ratio of water to methyl formate, the molar ratio of reflux to feed and the theoretic stages of reaction and separation sections, then a more appropriate operation condition was proposed. The results show that the simulated results are in good agreement with the experiments and the hydrolysis rate can be increased by changing operation conditions to adjust the concentrations of water and methyl formate in the reaction section. It is found that increasing the height of the reaction section is more favorable than that of the separation section, the methanol can be separated from the formic acid completely in a catalytic distillation column, and in the reaction section, the reaction rate at the top and bottom ends of the section are higher than that at the middle.