Abstract: This research investigated the separation of products mixture of dichlorosilane,trichlorosilane and silicon tetrachloride in the trichlorosilane synthesis process with the divided wall column instead of the conventional distillation sequences. The influences of reflux ratio,divided wall location,feed location,side-draw location,liquid split ratio and vapor split ratio on the mole fraction of distillate,side-draw and bottom products were simulated by Aspen Plus,and the optimal technological parameters were obtained. The energy consumption of separating the mixture mentioned above was compared between the divided wall column and the conventional distillation sequences. The simulation results showed that the separation effect was optimal when the reflux ratio was 6,divided wall was located the 8th stage and the 24th stage of main column,feed location was the 10th stage of prefractionator,side-draw location was the 15th stage of main column,liquid split ratio was 0.21 and vapor split ratio was 0.5. The mole fraction of trichlorosilane product can reach 99.999% under the above conditions. Compared with conventional distillation sequences,the reboiler duty and condenser duty of the divided wall column could be reduced more than 29.09% and 29.48% respectively.

Key words: simulation, separation, optimization, divided wall column

摘要： 以三氯氢硅合成过程中得到的主副产品混合物二氯二氢硅-三氯氢硅-四氯化硅为分离物系,提出采用隔壁塔代替常规精馏序列分离的新工艺.利用Aspen Plus软件对隔壁塔进行模拟,考察回流比、隔板位置、进料位置、侧线采出位置、液相分配比以及气相分配比对塔顶、侧线以及塔釜产品摩尔分数的影响,得到隔壁塔的最佳工艺参数,并通过模拟比较隔壁塔与常规精馏序列分离此混合物的能耗情况.模拟结果表明:当回流比为6、隔板位置为主塔的第8块板和第24块板、进料位置为预分馏塔的第10块板、侧线采出位置为主塔的第15块板、液相分配比为0.21、气相分配比为0.5时,隔壁塔的分离效果最佳,主产品三氯氢硅的摩尔分数为99.999%;相比于常规精馏序列,隔壁塔再沸器节能29.09%以上,冷凝器节能29.48%以上.

关键词: 模拟, 分离, 优化, 隔壁塔