聚乙烯醇聚合一塔的计算机优化及动态模拟

采用化工流程模拟软件，对聚乙烯醇生产中聚合工段聚合一塔进行了模拟计算。通过稳态灵敏度分析，优化了聚合一塔的最优操作点，即进料位置40块塔板，回流比0.7，馏出量6650 kg/h。动态研究表明，进料量、进料组成和回流量扰动均对一塔操作产生较大影响，其中，塔顶流量及组成动态响应速度缓慢，波动超过7 h，塔釜产品醋酸乙烯质量分数波动在扰动2~3 h时存在峰值；对于以塔底产品为主的聚合一塔，不能通过增加塔顶回流量来提高分离效果；串级控制通过改变吹入甲醇量可以快速有效控制塔釜产品醋酸乙烯含量。

Computer optimization and dynamic simulations for the NO.1 polymer distillation column in polyvinyl alcohol production

Using chemical process simulation software, the behavior in polymerization section Tower I in polyvinyl alcohol production has been simulated. Though steady-state sensitivity analysis, the operating point of the Tower I was optimized as follows: the location of the feed tray was 40, the reflux ratio was 0.7 and the distillate amount was 6650 kg/h. On this basis, the tower system dynamics simulation was conducted. The results showed that the feed rate, feed composition and return flow step disturbance all had a great impact on the operation. The flow rate and the composition at the top responded slowly and the volatility persisted for 7 h. Vinyl acetate content of the reboiler product peak fluctuated during disturbance for 2-3 h. It was found that simply increasing the return flow to a tower cannot improve the separation efficiency for bottom flow as the main product. In addition, cascade control by changing the blown amount of methanol can quickly and effectively control the vinyl acetate content of the reboiler product. 