变径塔精馏分离二元共沸物的经济性与动态特性

发布时间：2018-03-18 05:26

本文选题：变径塔　切入点：变压精馏　出处：《青岛科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：本文采用变径塔研究变压精馏与萃取精馏两种精馏方式分离丙酮-氯仿、丙酮-甲醇、甲醇-氯仿、苯-环己烷及异丙醇-二异丙醚五种常见共沸体系的工艺过程。考察五种共沸体系的精馏分离工艺,建立变径塔费用模型,基于最小年度总费用(TAC)采用序贯迭代法分别进行优化得到五个共沸体系变压精馏与萃取精馏最优工艺流程。计算每个体系采用变径塔后费用节省情况。从经济性角度分析,变压精馏比萃取精馏更适合采用变径塔。对于每种体系,变压精馏费用节省百分比均大于萃取精馏。研究甲醇-氯仿体系无热集成、部分热集成和完全热集成方式采用变径塔的变压精馏工艺并计算TAC。经济性上三种热集成方式TAC最小的为完全热集成工艺,采用变径塔后费用节省情况分别为:无热集成10.36%,部分热集成10.36%,完全热集成15.73%。可控性方面,以普通的无热集成工艺和经济性最好的完全热集成工艺为例做了研究。采用变径塔后的完全热集成工艺,其动态控制难度与无热集成工艺动态可控性难度基本一致,通过添加常用的控制结构均可实现有效的控制。探索了丙酮-甲醇体系变压与萃取两种精馏方式采用变径塔后的动态特性。变压精馏工艺通过改进控制结构最终可对±20%的进料流率和进料组成扰动进行稳健的控制;萃取精馏工艺控制结构的设定有一个相对复杂的过程,最终控制结构能处理±10%进料流率与进料组成扰动。从可控性角度,采用变径塔后变压精馏工艺可控性相对较好,更适合采用变径塔。本文首次从经济性与动态特性两方面探索研究采用变径塔分离共沸物的精馏工艺,总结了采用变径塔的变压精馏与萃取精馏的一般规律,对此类特殊精馏塔分离工艺的方案设计及生产投资评估具有指导意义。
[Abstract]:In this paper, the separation of acetone-chloroform, acetone-methanol, methanol-chloroform by pressure swing distillation and extractive distillation with variable diameter column was studied. The technological process of benzene-cyclohexane and isopropanol-diisopropyl ether azeotropic systems were studied. The distillation and separation processes of five azeotropic systems were investigated and the cost model of variable diameter column was established. Based on the minimum annual total cost (TAC), five azeotropic systems were optimized by sequential iteration method to obtain the optimal process flow of pressure variable distillation and extraction distillation. The cost saving of each system was calculated after adopting the variable diameter column, and analyzed from the economic point of view. The variable-diameter column is more suitable for variable-pressure distillation than extractive distillation. For each system, the cost saving percentage of variable-pressure distillation is greater than that of extractive distillation. No thermal integration of methanol-chloroform system is studied. Partial thermal integration and complete thermal integration are performed by variable pressure distillation process of variable diameter tower and calculation of TAC.The minimum of the three thermal integration modes TAC in economy is full thermal integration process. The cost savings after adopting the variable diameter tower are as follows: heat free integration 10.36, partial thermal integration 10.36, complete heat integration 15.73. controllability, Taking the common heat free integrated process and the best economical complete thermal integration process as an example, the dynamic control difficulty of the complete thermal integration process after adopting the variable diameter tower is basically the same as the dynamic controllability difficulty of the heat free integration process. Effective control can be achieved by adding common control structures. The dynamic characteristics of acetone-methanol system with variable pressure distillation and extraction with variable diameter column are explored. The variable pressure distillation process finally improves the control structure. The 卤20% feed flow rate and feed composition disturbance can be controlled stably. The setting of control structure of extractive distillation process has a relatively complex process, and the final control structure can deal with the disturbance of 卤10% feed flow rate and feed composition. From the point of view of controllability, the controllability of variable pressure distillation process after variable diameter column is relatively good. In this paper, the process of separating azeotrope with variable diameter column is studied for the first time from two aspects of economic and dynamic characteristics, and the general rules of variable pressure distillation and extractive distillation with variable diameter column are summarized. It is of guiding significance for the scheme design and production investment evaluation of this kind of special distillation column separation process.
【学位授予单位】：青岛科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ028.31

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