某工厂低温甲醇洗工艺原料气分为2股，现有扩产的需求。为实现低温甲醇洗工艺扩产目的，采用Aspen Plus软件基于PSRK物性方法对工艺的实际工况进行了模拟，得到的模拟值与实际值较为符合，从而确定了PSRK为低温甲醇洗工艺模拟的物性方法。在此基础上提出了一种改造方案：新增2台换热器用来预冷原料气；新增氮气汽提塔用来汽提吸收塔甲醇所溶解的酸性气体，甲醇的温度和甲醇中CO₂的摩尔分数得以降低，因此甲醇的吸收能力有了明显提高；新增1台进料泵用于输送汽提后的甲醇到吸收塔。同时通过灵敏度分析确定出了改造工艺的最优参数：N₂进料量为300 kmol/h，理论板数为7，分流比为0.020。经过以上改造，各产品流股均符合工艺要求，达到扩产20%的目的。对改造后工艺的操作弹性做进一步分析表明最大扩产幅度可达26%，为实际扩产提供了一定裕度。

There are two feed gas streams in the rectisol stage in a certain plant that plans to expand production.To achieve expansion in the rectisol stage,the actual working condition of this original rectisol process is simulated by using Aspen Plus on the basis of PSRK property method.Because the simulation values match well with the actual operation data,PSRK is determined as the optimal property method for rectisol simulation.Hence,a revamping scheme is proposed as follows:two additional heat exchangers are used to precool feed gas,a new nitrogen stripping tower is also added to strip the dissolved acid gas contained in the methanol in the absorbing tower and a new pump is added to transport stripped methanol into the absorbing tower.Therefore,both the temperature of methanol and the content of CO₂ in the methanol are reduced,which leads to an obviously increasing absorption capacity of methanol.Meanwhile,the optimal parameters are determined by sensitivity analysis as follows:feed flow of N₂ is 300 kmol·h^-1,number of theoretical plates is 7 and split ratio is 0.020.After these innovations,various product streams conform to process requirements and the 20% expansion target is achieved.Finally,the operation flexibility analysis on revamped process shows that the maximum capacity can be expanded by 26%,providing a margin for actual expansion.

许东(1991-),男,硕士生