隔板精馏塔分离氯化亚砜的模拟及工艺优化

Simulation and optimization of divided wall column for separating thionyl chloride

利用AspenPlus软件对常规的两塔间接序列精馏工艺分离氯化亚砜进行了模拟计算,并提出了一种新型分离工艺—隔板精馏塔工艺。通过对隔板精馏塔的模拟计算,研究了预分离段进料位置、侧线采出位置、回流进料比和分配比对产品纯度和再沸器能耗的影响,结果说明最佳的工艺条件为:预分离段第6块板进料,主塔第55块板采出,回流进料比为4.45,液相分配比为1.60,汽相分配比为1.98。将隔板塔在最佳操作条件下的能耗与常规两塔工艺操作能耗和设备投资进行比较,隔板精馏塔节约冷凝器负荷和再沸器负荷分别为34.62%和34.64%;然后运用专业的设备投资计算软件CAPCOST计算2种工艺设备投资,结果表明,隔板精馏塔新工艺可以降低17.27%的设备投资。综上可知隔板精馏分离氯化亚砜是一种节能、高效的新型分离工艺。

The indirect sequence as a conventional process was simulated by using Aspen Plus software for the separation of thionyl chloride.And divided wall column （DWC）was proposed as an innovative process to separate thionyl chloride.Furthermore,the effect of feed stage,side draw stage,the ratio of reflux rate to feed and distribution ratio on the product purity and reboiler duty was discussed.The optimum operating conditions determined are as follows：the feed stage is the 6th tray of pre-fractionator,the side draw stage is the 55th tray of main column,the ratio of reflux rate to feed is 4.45,the liquid distribution ratio is 1.60,and the vapor distribution ratio is 1.98.The results show that DWC operated in optimal conditions can save condenser duty and reboiler duty by 34.62% and 34.64% respectively,compared with the conventional indirect sequence.Meanwhile,DWC can save capital cost by 17.27% from the calculating result of CAPCOST software.So DWC for the separation of thionyl chloride is an energy saving and efficient separation technology.