隔壁塔萃取精馏分离碳酸二甲酯-甲醇的优化与控制
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摘要
利用Aspen Plus软件,采用隔壁塔萃取精馏(EDWC)工艺,对碳酸二甲酯-甲醇共沸体系进行有效分离。稳态分析结果表明,EDWC比常规萃取精馏可减少再沸器负荷37.66%,年度总费用(TAC)可降低36.89%。在动态控制系统中,针对EDWC中主塔温度分布均匀、灵敏板选择困难的问题,给出一种简单有效的导斜率判据方法。利用Aspen Dynamics软件考察了主塔不同灵敏板以及3种控制结构的有效性。结果表明,当主塔灵敏板为第12块塔板时,采用带气相分配比的控制结构(CS2)能实现稳定控制。当主塔灵敏板为第5块塔板时,采用无气相分配比的控制结构(CS3)能有效处理进料流量和组成发生的±20%扰动,为较优的控制方案。
The extractive dividing wall column(EDWC)process for separation dimethyl carbonate and methanol system was investigated by means of Aspen Plus.From the steady state results,it was found that compared with the traditional extractive distillation process,the EDWC process could achieve up to 37.66% savings of the energy consumption and reduce the total annual cost(TAC)by 36.89%.For the dynamic control system,aiming at the problems of choosing the suitable sensitive stage caused by the uniform temperature distribution of the main column,we proposed a simple and effective scheme.The influences of the selection of the sensitive stages and three dynamic control structures on the dynamic responses in the EDWC process were further studied using Aspen Dynamics.The dynamic simulation results revealed that the improved control structures with vapor split ratio(CS2)with stage 12 in the main column selected as the control stage showed effective control performance.When the stage 5 in the main column was selected as the control stage,control structure without vapor split ratio(CS3)could act as the control scheme because of its more practicality in application than the CS2,and more efficient dynamic controllability for the±20%feed flow rate and feed composition disturbances.
The extractive dividing wall column(EDWC)process for separation dimethyl carbonate and methanol system was investigated by means of Aspen Plus.From the steady state results,it was found that compared with the traditional extractive distillation process,the EDWC process could achieve up to 37.66% savings of the energy consumption and reduce the total annual cost(TAC)by 36.89%.For the dynamic control system,aiming at the problems of choosing the suitable sensitive stage caused by the uniform temperature distribution of the main column,we proposed a simple and effective scheme.The influences of the selection of the sensitive stages and three dynamic control structures on the dynamic responses in the EDWC process were further studied using Aspen Dynamics.The dynamic simulation results revealed that the improved control structures with vapor split ratio(CS2)with stage 12 in the main column selected as the control stage showed effective control performance.When the stage 5 in the main column was selected as the control stage,control structure without vapor split ratio(CS3)could act as the control scheme because of its more practicality in application than the CS2,and more efficient dynamic controllability for the±20%feed flow rate and feed composition disturbances.
引文
[1]WANG S J,YU C C,Huang H P.Plant-wide design and control of DMC synthesis process via reactive distillation and thermally coupled extractive distillation[J].Comput Chem Eng,2010,34(3):361-373.
[2]DAI X,YE Q,QIN J W,et al.Energy-saving dividingwall column design and control for benzene extraction distillation via mixed entrainer[J].Chem Eng Process,2015,100:49-64.
[3]索潇萌,戴昕,虞昊,等.分隔壁萃取精馏塔分离乙酸乙酯-异丙醇[J].石油学报(石油加工),2016,32(1):111-118.(SUO Xiaomeng,DAI Xin,YU Hao,et al.Separation of ethyl acetate-isopropyl alcohol by extractive dividing wall column[J].Acta Petrolei Sinica(Petroleum Processing Section),2016,32(1):111-118.)
[4]李军,王纯正,马占华,等.基于Aspen Plus和NSGA-Ⅱ的隔壁塔多目标优化研究[J].高校化学工程学报,2015,29(2):400-406.(LI Jun,WANG Chunzheng,MA Zhanhua,et al.Multi-objective optimization of dividing wall columns with Aspen Plus and NSGA-Ⅱ[J].Journal of Chemical Engineering of Chinese Universities,2015,29(2):400-406.)
[5]HAO L,LUYBEN W L.New control structure for divided-wall columns[J].Ind Eng Chem Res,2009,48(13):6034-6049.
[6]秦继伟,张浩,熊晓娟,等.分隔壁萃取精馏塔分离苯-环己烷体系的研究[J].石油学报(石油加工),2014,30(4):687-693.(QIN Jiwei,ZHANG Hao,XIONG Xiaojuan,et al.Separation of benzene-cyclohexane system by extractive dividing wall column[J].Acta Petrolei Sinica(Petroleum Processing Section),2014,30(4):687-693.)
[7]YU J,WANG S J,HUANG K,et al.Improving the performance of extractive dividing-wall columns with intermediate heating[J].Ind Eng Chem Res,2015,54(10):2709-2723.
[8]SUN L Y,WANG Q Y,LI L M,et al.Design and control of extractive dividing wall column for separating benzene/cyclohexane mixtures[J].Ind Eng Chem Res,2014,53(19):8120-8131.
[9]刘育良,翟建,李鲁闽,等.萃取精馏分离苯/环己烷共沸体系的控制策略[J].化工学报,2015,66(9):3618-3632.(LIU Yuliang,ZHAI Jian,LI Lumin,et al.Operation and control of extractive distillation for separation of azeotropic benzene/cyclohexane system[J].CIESC Journal,2015,66(9):3618-3632.)
[10]ZHANG H,YE Q,QIN J W,et al.Design and control of extractive dividing-wall column for separating ethyl acetate-isopropyl alcohol mixture[J].Ind Eng Chem Res,2013,53(3):1189-1205.
[11]HSU K Y,HSIAO Y C,CHIEN I.Design and control of dimethyl carbonate-methanol separation via extractive distillation in the dimethyl carbonate reactive-distillation process[J].Ind Eng Chem Res,2009,49(2):735-749.
[12]RODRIGUEZ A,CANOSA J,DOMINGUEZ A,et al.Vapour-liquid equilibria of dimethyl carbonate with linear alcohols and estimation of interaction parameters for the UNIFAC and ASOG method[J].Fluid Phase Equilib,2002,201(1):187-201.
[13]李春山,张香平,张锁江,等.加压-常压精馏分离甲醇-碳酸二甲酯的相平衡和流程模拟[J].过程工程学报,2003,3(5):453-458.(LI Chunshan,ZHANG Xiangping,ZHANG Suojiang,et al.Vapor-liquid equilibria and process simulation for separation of dimethyl carbonate and methanol azeotropic system[J].The Chinese Journal of Process Engineering,2003,3(5):453-458.)
[14]杨德明,王杨,廖巧,等.基于双塔精馏的甲醇-碳酸二甲酯分离工艺[J].化工进展,2012,31(5):1165-1168.(YANG Deming,WANG Yang,LIAO Qiao,et al.Separation technology for methanol-dimethyl carbonate system by double column distillation[J].Chemical Industry and Engineering Progress,2012,31(5):1165-1168.)
[15]LUYBEN W L.Distillation design and control using Aspen simulation[M].New York:John Wiley&Sons,2013:115-133.
[16]ZHANG Q R,PENG J Y,ZHANG K.Separation of an azeotropic mixture of dimethyl carbonate and methanol via partial heat integration pressure swing distillation[J].Asia Pac J Chem Eng,2017,12(1):50-64.
[17]XIA M,XIN Y P,LUO J W,et al.Temperature control for extractive dividing-wall column with an adjustable vapor split:Methylal/methanol azeotrope separation[J].Ind Eng Chem Res,2013,52(50):17996-18013.
[2]DAI X,YE Q,QIN J W,et al.Energy-saving dividingwall column design and control for benzene extraction distillation via mixed entrainer[J].Chem Eng Process,2015,100:49-64.
[3]索潇萌,戴昕,虞昊,等.分隔壁萃取精馏塔分离乙酸乙酯-异丙醇[J].石油学报(石油加工),2016,32(1):111-118.(SUO Xiaomeng,DAI Xin,YU Hao,et al.Separation of ethyl acetate-isopropyl alcohol by extractive dividing wall column[J].Acta Petrolei Sinica(Petroleum Processing Section),2016,32(1):111-118.)
[4]李军,王纯正,马占华,等.基于Aspen Plus和NSGA-Ⅱ的隔壁塔多目标优化研究[J].高校化学工程学报,2015,29(2):400-406.(LI Jun,WANG Chunzheng,MA Zhanhua,et al.Multi-objective optimization of dividing wall columns with Aspen Plus and NSGA-Ⅱ[J].Journal of Chemical Engineering of Chinese Universities,2015,29(2):400-406.)
[5]HAO L,LUYBEN W L.New control structure for divided-wall columns[J].Ind Eng Chem Res,2009,48(13):6034-6049.
[6]秦继伟,张浩,熊晓娟,等.分隔壁萃取精馏塔分离苯-环己烷体系的研究[J].石油学报(石油加工),2014,30(4):687-693.(QIN Jiwei,ZHANG Hao,XIONG Xiaojuan,et al.Separation of benzene-cyclohexane system by extractive dividing wall column[J].Acta Petrolei Sinica(Petroleum Processing Section),2014,30(4):687-693.)
[7]YU J,WANG S J,HUANG K,et al.Improving the performance of extractive dividing-wall columns with intermediate heating[J].Ind Eng Chem Res,2015,54(10):2709-2723.
[8]SUN L Y,WANG Q Y,LI L M,et al.Design and control of extractive dividing wall column for separating benzene/cyclohexane mixtures[J].Ind Eng Chem Res,2014,53(19):8120-8131.
[9]刘育良,翟建,李鲁闽,等.萃取精馏分离苯/环己烷共沸体系的控制策略[J].化工学报,2015,66(9):3618-3632.(LIU Yuliang,ZHAI Jian,LI Lumin,et al.Operation and control of extractive distillation for separation of azeotropic benzene/cyclohexane system[J].CIESC Journal,2015,66(9):3618-3632.)
[10]ZHANG H,YE Q,QIN J W,et al.Design and control of extractive dividing-wall column for separating ethyl acetate-isopropyl alcohol mixture[J].Ind Eng Chem Res,2013,53(3):1189-1205.
[11]HSU K Y,HSIAO Y C,CHIEN I.Design and control of dimethyl carbonate-methanol separation via extractive distillation in the dimethyl carbonate reactive-distillation process[J].Ind Eng Chem Res,2009,49(2):735-749.
[12]RODRIGUEZ A,CANOSA J,DOMINGUEZ A,et al.Vapour-liquid equilibria of dimethyl carbonate with linear alcohols and estimation of interaction parameters for the UNIFAC and ASOG method[J].Fluid Phase Equilib,2002,201(1):187-201.
[13]李春山,张香平,张锁江,等.加压-常压精馏分离甲醇-碳酸二甲酯的相平衡和流程模拟[J].过程工程学报,2003,3(5):453-458.(LI Chunshan,ZHANG Xiangping,ZHANG Suojiang,et al.Vapor-liquid equilibria and process simulation for separation of dimethyl carbonate and methanol azeotropic system[J].The Chinese Journal of Process Engineering,2003,3(5):453-458.)
[14]杨德明,王杨,廖巧,等.基于双塔精馏的甲醇-碳酸二甲酯分离工艺[J].化工进展,2012,31(5):1165-1168.(YANG Deming,WANG Yang,LIAO Qiao,et al.Separation technology for methanol-dimethyl carbonate system by double column distillation[J].Chemical Industry and Engineering Progress,2012,31(5):1165-1168.)
[15]LUYBEN W L.Distillation design and control using Aspen simulation[M].New York:John Wiley&Sons,2013:115-133.
[16]ZHANG Q R,PENG J Y,ZHANG K.Separation of an azeotropic mixture of dimethyl carbonate and methanol via partial heat integration pressure swing distillation[J].Asia Pac J Chem Eng,2017,12(1):50-64.
[17]XIA M,XIN Y P,LUO J W,et al.Temperature control for extractive dividing-wall column with an adjustable vapor split:Methylal/methanol azeotrope separation[J].Ind Eng Chem Res,2013,52(50):17996-18013.