ChemCAD模拟分离混合二元酸二甲酯研究

Chem CAD simulation of mixed dibasic acid dimethyl ester distillation

采用ChemCAD软件对混合二元酸二甲酯的精馏分离过程进行模拟。首先选用简捷精馏模型分别对己二酸二甲酯和戊二酸二甲酯混合物,戊二酸二甲酯和丁二酸二甲酯混合物进行初步分离模拟,再选用联立矫正精馏模型进行两步间歇精馏模拟,得到合适的精馏条件。结果表明:精馏塔Ⅰ和精馏塔Ⅱ的塔板数均为22,塔顶压力为0.01 MPa,塔压降为0.001 MPa,再沸器温度小于423 K,进料口在塔板数12处,精馏塔Ⅰ最小回流比为2.42,精馏塔Ⅱ最小回流比为0.69时,进行模拟精馏,得到丁二酸二甲酯的纯度为99.60%,戊二酸二甲酯的纯度为99.61%,己二酸二甲酯的纯度为99.70%;根据模拟结果,采用精馏装置对混合二元酸二甲酯进行实验验证,实验结果与模拟结果相近。

The distillation and separation of mixed dibasic acid dimethyl ester were simulated by using Chem CAD software. A shortcut column model was used to preliminarily simulate the separation process of the mixture of dimethyl adipate and dimethyl glutarate and the mixture of dimethyl glutarate and dimethyl succinate. The appropriate distillation conditions were explored by two-step batch distillation simulation with Simultaneous Correction Distillation model. The results showed that the purity of dimethyl succinate,dimethyl glutarate and dimethyl adipate was 99. 60%,99. 61% and 99. 70%,respectively,when the distillation conditions were as followed： 22 pieces of trays for distillation columns I and Ⅱ,top pressure 0. 01 MPa,pressure drop 0. 001 MPa,reboiler temperature below 423 K,feeding inlet at the twelfth tray,minimum reflux ratio 2. 42 and 0. 69 respectively for distillation columns I and Ⅱ; and the simulation results was close to the experimental results of separating the mixed dibasic acid dimethyl ester on a distillation unit.