变压精馏分离丙酮和环己烷的动态特性  

Dynamics performance of pressure swing distillation for acetone and cyclohexane separation

作　　者：张春花 诸林[1] 吕利平[2] 周倩 金仕胜 Chunhua ZHANG;Lin ZHU;Liping Lü;Qian ZHOU;Shisheng JIN(College of Chemistry and Chemical Engineering,Southwest Petroleum University,Chengdu,Sichuan 610500,China;College of Chemistry and Chemical Engineering,Yangtze Normal University,Fuling,Chongqing 408000,China)

机构地区：[1]西南石油大学化学化工学院,四川成都610500 [2]长江师范学院化学化工学院,重庆涪陵408000

出　　处：《过程工程学报》2022年第2期249-257,共9页The Chinese Journal of Process Engineering

摘　　要：基于丙酮-环己烷共沸体系的压力敏感性,利用Aspen Plus软件,以年度总费用(TAC)最小为目标函数对常规、部分及完全热集成变压精馏工艺进行稳态模拟与优化,并以经济最优的完全热集成变压精馏工艺为基础,借助Aspen Plus Dynamics软件建立多种不同控制结构,通过改变进料流量和进料组成考察了控制结构的有效性,并提出塔底热负荷/进料量比例控制与组成-温度串级控制相结合的改进控制结构。稳态模拟与优化结果表明,常规、部分和完全热集成三种工艺的最小TAC分别为3.64×10^(5),2.83×10^(5),2.76×10^(5)$/y,经济最优工艺为完全热集成变压精馏。动态响应结果表明固定回流量/进料量控制结构在响应时间方面优于固定回流比控制结构,但产品纯度未达到设计值99.9wt%;而塔底热负荷/进料量比例控制与组成-温度串级控制相结合的改进控制结构能够有效保证产品纯度在99.9wt%及以上。As significant chemical raw material and solvent,acetone and cyclohexane are widely applied in chemical industry.However,the mixture of them will form a minimum boiling homogeneous azeotrope at atmospheric pressure,which severely hinders the separation of them.Based on the advantages of pressure swing distillation(PSD)and the pressure sensitivity of the azeotropic mixture of acetone and cyclohexane,the investigation of the design and the simulation of PSD are implemented by Aspen Plus software.The results show that the purity of products achieve 99.9 wt%.In order to save the total annual cost(TAC)and energy,based on the heat integration technology and economic optimization,it is implemented that the process enhancement with the minimum TAC as objective function.Furthermore,the TAC of the steady-state process of conventional,partial and full heat integration PSD are 3.64×10^(5),2.83×10^(5),2.76×10^(5)$/y,respectively.Compared with the conventional PSD,the economic reduction rate of partial and full heat integration are 22.36%and 24.18%,respectively,and the full heat integration is most economical.In view of these,the different control structures are established by Aspen Plus Dynamics,and the anti-disturbance performance is investigated by changing the feed flow rate and composition,the dynamic performance of the full heat integration PSD process is assessed.The dynamic response results indicate that the control structure with a fixed reflux-to-feed flow rate ratio is better than the control structure with a fixed reflux ratio in terms of settlement time.However,the control structure with a fixed reflux-to-feed flow rate ratio cannot maintain product purity,up to the design value of 99.9 wt%.For meet the goal of the requirements of products purities,an improved control structure with feed forward proportional(reboiler heat duty to feed flow rate ratio)control and composition-temperature cascade control are proposed,which can effectively ensure that the product purity reaches more than 99.9 wt%.

关 键 词：丙酮 环己烷 变压精馏 热集成 动态特性 

分 类 号：TQ028.31[化学工程]