有序搜索法加调优法研究有机硅单体的分离序列

Research of separation sequence for organosilicon mixture by ordered search and optimization methods

针对有机硅单体混合物(甲基氯硅烷混合物)中组分较多、分离塔系复杂的特点,提出了利用有序搜索法加调优法研究其最优分离序列的方法。利用AspenPlus模拟软件中的DSTWU模块和WILSON热力学计算模型,对提出的合成序列中涉及到的各分离子问题进行初步模拟计算。将模拟结果代入相关的费用计算模型,并利用探试成本函数概念,估算不同切割位置分离序列的年总成本。以年总成本最低为目标函数,利用有序搜索法递减确定不同组分混合物的最佳切割点。结果表明,序列Ⅰ为最佳切割点分离序列。然后,以序列Ⅰ作为初始序列,提出相关的3组相邻分离序列,采用渐进调优法对其进行调优。利用AspenPlus模拟软件中的RADFRAC严格精馏计算模块对以上4组分离序列进行精确模拟计算,分别对其各塔的进料位置和回流比进行优化,将优化结果代入相关的费用计算模型,计算并比较以上4组序列的年总成本。研究结果表明,序列Ⅳ的年总成本最低,较初始序列Ⅰ的年总成本降低了2.31%,因此选择序列Ⅳ作为分离有机硅单体混合物的最优方案是合适的。

The ordered search and optimization methods were proposed to study the synthesis of optimal separation sequence of organosilicon mixture which was composed of some kinds of methylchlorosilane and required many more columns to separate from each other by distillation. Simulations of separation subproblems concerned in the process were performed by Aspen Plus software in which the DSTWU and WILSON physical property set were used. The simulation results were substituted in the cost models and annual total costs of separation sequences were estimated, taking account of heuristic cost function. Taking the minimum annual total cost as an objective function, the optimal separation positions of different mixture of methylchlorosilane were determined by the method of ordered search. Then sequence I was achieved. Taking sequence I as the primary separation sequence, three kinds of separation sequences similar to the primary one were presented and the optimal separation sequence was obtained through the method of optimization. Simulations of four kinds of separation sequences mentioned above were performed by Aspen Plus software in which the RADFRAC was used. The optimum feed stage and reflux ratio of columns concerned in the four sequences were determined. The optimized simulation results were substituted in the cost models and annual total costs of four sequences were achieved. Compare the annual total costs and the result showed that sequence IV had the minimum annual total cost, and saved 2.31% cost, comparing with the primary sequence. Finally, it was advisable to choose sequence IV as a optimal sequence.