快速变压吸附制氧动态传质系数模拟分析
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摘要
研究快速变压吸附制氧过程中的传质过程,结合实验数据对全局动态传质系数与常数传质系数进行对比模拟分析,并考察各传质阻力对传质效果的影响。结果表明:基于轴向、膜扩散和孔扩散估算的动态传质系数是有效的。膜阻力是主要阻力,其次是轴向扩散阻力,大孔扩散阻力较小,微孔扩散阻力可忽略。在快速变压吸附中,由于气速和温度变化较快,传质系数也会有较大变化,总体趋势是传质系数随着温度和气速的升高而升高。采用恒定传质系数无法准确描述吸附塔内各个时间点、空间点上的传质行为,根据各节点状态计算出的动态估算传质系数能够与吸附塔内的行为有较好的吻合度,模型具有较高的可信性。
The mass transfer process of RPSA(rapid pressure swing adsorption) and the effect of varions mass transfer resistances on mass transfer were investigated. The global dynamic mass transfer coefficient was compared with constant mass transfer coefficient. The results show that the dynamic mass transfer coefficients based on axial, membrane diffusion and pore diffusion estimation are effective. Membrane resistance takes up a large part of lumped resistance. Followed by axial diffusion resistance, the macrospores diffusion resistance and the micropores diffusion resistance can be neglected. In the rapid PSA, the mass transfer coefficient will change due to the rapid change of gas velocity and temperature, and the overall trend is that the mass transfer coefficient increases with the increase of temperature and gas velocity. Using the constant mass transfer coefficient cannot accurately describe the mass transfer behavior at each time point and space point in the absorber. The dynamic estimation mass transfer coefficient calculated according to the state of each node can have good coincidence with the behavior in the absorption bed, and the model has high reliability.
The mass transfer process of RPSA(rapid pressure swing adsorption) and the effect of varions mass transfer resistances on mass transfer were investigated. The global dynamic mass transfer coefficient was compared with constant mass transfer coefficient. The results show that the dynamic mass transfer coefficients based on axial, membrane diffusion and pore diffusion estimation are effective. Membrane resistance takes up a large part of lumped resistance. Followed by axial diffusion resistance, the macrospores diffusion resistance and the micropores diffusion resistance can be neglected. In the rapid PSA, the mass transfer coefficient will change due to the rapid change of gas velocity and temperature, and the overall trend is that the mass transfer coefficient increases with the increase of temperature and gas velocity. Using the constant mass transfer coefficient cannot accurately describe the mass transfer behavior at each time point and space point in the absorber. The dynamic estimation mass transfer coefficient calculated according to the state of each node can have good coincidence with the behavior in the absorption bed, and the model has high reliability.
引文
[1]RAO V R,KOTHARE M V,SIRCAR S.Novel design and performance of a medical oxygen concentrator using a rapid pressure swing adsorption concept[J].AICh E Journal,2014,60(9):3330-3335.
[2]银醇彪,张东辉,鲁东东,等.数值模拟和优化变压吸附流程研究进展[J].化工进展,2014,33(3):550-557.YIN C B,ZHANG D H,LU D D,et al.Progress in numerical simulation and optimization of pressure swing adsorption process[J].Chemical Industry and Engineering Progress,2014,33(3):550-557.
[3]SIRCAR S,HUFTON J R.Why does the linear driving force model for adsorption kinetics work?[J].Adsorption-Journal of the International Adsorption Society,2000,6(2):137-147.
[4]关建郁,谢侃生,叶振华.色谱法测定氧和氮在13X分子筛上的吸附平衡常数及传质系数[J].离子交换与吸附,1992,(6):501-507.GUAN J Y,XIE K S,YE Z H.Determination of adsorption equilibrium constants and mass transfer coefficients of oxygen and nitrogen on 13X zeolite by chromatography[J].Ion Exchange and Adsorption,1992,(6):501-507.
[5]ZHONG G,RANKIN P J,ACKLEY M W.High frequency PSA process for gas separation:US00782878B2[P].2007-11-9.
[6]VEMULA R R,KOTHARE M V,SIRCAR S.Performance of a medical oxygen concentrator using rapid pressure swing adsorption process:effect of feed air pressure[J].AICh E Journal,2016,62(4):1212-1215.
[7]WU C W,KOTHARE M V,SIRCAR S.Column dynamic study of mass transfer of pure N2 and O2 into small particles of pelletized Li LSX zeolite[J].Ind.Eng.Chem.Res.,2014,54(18):5195-5195.
[8]WU C W,VEMULA R R,KOTHARE M V,et al.Experimental study of a novel rapid pressure-swing adsorption based medical oxygen concentrator:effect of the adsorbent selectivity of N2 over O2[J].Industrial&Engineering Chemistry Research,2016,55(16):4676-4681.
[9]RAO V R,WU C W,KOTHARE M V,et al.Comparative perfomances of two commercial samples of Li LSX zeolite for production of 90%oxygen from air by a novel rapid pressure swing adsorption system[J].Separation Science&Technology,2015,50(10):1447-1452.
[10]RAO V R,CHAI S W,KOTHARE M V,et al.Chem Inform abstract:highlights of non-equilibrium,non-isobaric,non-isothermal desorption of nitrogen from a Li X zeolite column by rapid pressure reduction and rapid purge by oxygen[J].Adsorption-Journal of the International Adsorption Society,2014,20(2/3):477-481.
[11]卜令兵,刘应书,刘文海,等.压力对微型变压吸附制氧的影响[J].化工进展,2006,25(5):569-572.BU L B,LIU Y S,LIU W H,et al.Influence of pressure on miniature PSA oxygen generator[J].Chemical Industry and Engineering Progress,2006,25(5):569-572.
[12]宗航,刘应书,刘文海,等.单吸附床微型真空变压吸附制氧实验研究[J].深冷技术,2006,(6):24-28.ZONG H,LIU Y S,LIU W H,et al.Experimental study on miniature single-bed VPSA for oxygen concentration[J].Cryogenic Technology,2006,(6):24-28.
[13]宗航,刘应书,刘文海,等.微型单塔RPSA制氧工艺参数实验研究[J].气体分离,2005,(6):17-21.ZONG H,LIU Y S,LIU W H,et al.Experimental study on oxygen production parameters of micro single tower RPSA[J].Gas Separation,2005,(6):17-21.
[14]祝显强,刘应书,杨雄,等.吸附及解吸压力对快速变压吸附床内速度及循环性能的影响[J].北京科技大学学报,2016,38(7):993-1001.ZHU X Q,LIU Y S,YANG X,et al.Effect of adsorption and desorption pressure on the velocity and cycling performance of rapid pressure swing adsorption[J].Journal of University of Science and Technology Beijing,2016,38(7):993-1001.
[15]祝显强,刘应书,杨雄,等.中间气两步充压对快速真空变压吸附制氧的影响[J].化工学报,2016,67(10):4264-4272.ZHU X Q,LIU Y S,YANG X,et al.Effect of two-step pressurization with intermediate gas on rapid vacuum pressure swing adsorption process for oxygen generation[J].CIESC Journal,2016,67(10):4264-4272.
[16]祝显强,刘应书,焦璐璐,等.快速真空变压吸附制氧的排放气充压过程研究[J].北京科技大学学报,2015,37(11):1513-1519.ZHU X Q,LIU Y S,JIAO L L,et al.Study on pressurization with raffinate in a rapid vacuum pressure swing adsorption process for producing oxygen[J].Journal of University of Science and Technology Beijing,2015,37(11):1513-1519.
[17]TODD R S,WEBLEY P A.Mass-transfer models for rapid pressure swing adsorption simulation[J].AICh E Journal,2010,52(9):3126-3145.
[18]BAE Y S,LEE C H.Sorption kinetics of eight gases on a carbon molecular sieve at elevated pressure[J].Carbon,2005,43(1):95-107.
[19]BAE Y S,MOON J H,AHN H,et al.Effects of adsorbate properties on adsorption mechanism in a carbon molecular sieve[J].Korean Journal of Chemical Engineering,2004,21(3):712-720.
[20]LI D D,ZHOU Y,SHEN Y H,et al.Experiment and simulation for separating CO2/N2 by dual-reflux pressure swing adsorption process[J].Chemical Engineering Journal,2016,297:315-324.
[21]YAN H Y,FU Q,ZHOU Y,et al.CO2 capture from dry flue gas by pressure vacuum swing adsorption:a systematic simulation and optimization[J].International Journal of Greenhouse Gas Control,2016,51:1-10.
[22]YIN C B,SUN W N,YANG H W,et al.Optimization of three-bed VPSA system for biogas upgrading[J].Chemical Engineering Science,2015,135:100-108.
[23]周言,沈圆辉,付强,等.真空变压吸附分离CH4/N2/O2实验、模拟与安评[J].化工学报,2017,68(2):723-731.ZHOU Y,SHEN Y H,FU Q,et al.Experiment,simulation and safety evaluation of vacuum pressure swing adsorption for CH4/N2/O2separation[J].CIESC Journal,2017,68(2):723-731.
[24]杨彦钢,丁艳宾,马正飞,等.不同均压方式对PSA和VSA空分制氧过程的影响[J].南京工业大学学报(自然科学版),2012,34(4):79-83.YANG Y G,DING Y B,MA Z F,et al.Effects of different pressure equalization methods on PSA and VSA processes for O2 production from air[J].Journal of Nanjing University of Technology(Natural Science Edition),2012,34(4):79-83.
[25]RIPE R H.PERRY化学工程手册[M].北京:化学工业出版社,1992:149.RIPE R H.PERRY Chemical Engineering Handbook[M].Beijing:Chemical Industry Press,1992:149.
[26]BONIFACE H A,RUTHVEN D M.Chromatographic adsorption with sinusoidal input[J].Chemical Engineering Science,1985,40(11):2053-2061.
[27]周圆圆,韦向攀,张东辉.三塔真空变压吸附富氧工艺过程模拟[J].化工进展,2011,30(S2):263-267.ZHOU Y Y,WEI X P,ZHANG D H.Simulation of three-bed VPSA oxygen enriched process[J].Chemical Industry and Engineering Progress,2011,30(S2):263-267.
[28]李绍芬.反应工程[M].3版.北京:化学工业出版社,2013:167-171.LI S F.Reaction Engineering[M].3rd ed.Beijing:Chemical Industry Press,2013:167-171.
[29]北川浩.吸附的基础与设计[M].鹿政理,译.北京:化学工业出版社,1983:69-71.HIROSHI K.The Basis and Design of Adsorption[M].LU Z L,trans.Beijing:Chemical Industry Press,1983:69-71.
[30]RUTHVEN D M.Principles of Adsorption&Adsorption Processes[M].New York:John Wiley&Sons Inc.,1984:134-159.
[2]银醇彪,张东辉,鲁东东,等.数值模拟和优化变压吸附流程研究进展[J].化工进展,2014,33(3):550-557.YIN C B,ZHANG D H,LU D D,et al.Progress in numerical simulation and optimization of pressure swing adsorption process[J].Chemical Industry and Engineering Progress,2014,33(3):550-557.
[3]SIRCAR S,HUFTON J R.Why does the linear driving force model for adsorption kinetics work?[J].Adsorption-Journal of the International Adsorption Society,2000,6(2):137-147.
[4]关建郁,谢侃生,叶振华.色谱法测定氧和氮在13X分子筛上的吸附平衡常数及传质系数[J].离子交换与吸附,1992,(6):501-507.GUAN J Y,XIE K S,YE Z H.Determination of adsorption equilibrium constants and mass transfer coefficients of oxygen and nitrogen on 13X zeolite by chromatography[J].Ion Exchange and Adsorption,1992,(6):501-507.
[5]ZHONG G,RANKIN P J,ACKLEY M W.High frequency PSA process for gas separation:US00782878B2[P].2007-11-9.
[6]VEMULA R R,KOTHARE M V,SIRCAR S.Performance of a medical oxygen concentrator using rapid pressure swing adsorption process:effect of feed air pressure[J].AICh E Journal,2016,62(4):1212-1215.
[7]WU C W,KOTHARE M V,SIRCAR S.Column dynamic study of mass transfer of pure N2 and O2 into small particles of pelletized Li LSX zeolite[J].Ind.Eng.Chem.Res.,2014,54(18):5195-5195.
[8]WU C W,VEMULA R R,KOTHARE M V,et al.Experimental study of a novel rapid pressure-swing adsorption based medical oxygen concentrator:effect of the adsorbent selectivity of N2 over O2[J].Industrial&Engineering Chemistry Research,2016,55(16):4676-4681.
[9]RAO V R,WU C W,KOTHARE M V,et al.Comparative perfomances of two commercial samples of Li LSX zeolite for production of 90%oxygen from air by a novel rapid pressure swing adsorption system[J].Separation Science&Technology,2015,50(10):1447-1452.
[10]RAO V R,CHAI S W,KOTHARE M V,et al.Chem Inform abstract:highlights of non-equilibrium,non-isobaric,non-isothermal desorption of nitrogen from a Li X zeolite column by rapid pressure reduction and rapid purge by oxygen[J].Adsorption-Journal of the International Adsorption Society,2014,20(2/3):477-481.
[11]卜令兵,刘应书,刘文海,等.压力对微型变压吸附制氧的影响[J].化工进展,2006,25(5):569-572.BU L B,LIU Y S,LIU W H,et al.Influence of pressure on miniature PSA oxygen generator[J].Chemical Industry and Engineering Progress,2006,25(5):569-572.
[12]宗航,刘应书,刘文海,等.单吸附床微型真空变压吸附制氧实验研究[J].深冷技术,2006,(6):24-28.ZONG H,LIU Y S,LIU W H,et al.Experimental study on miniature single-bed VPSA for oxygen concentration[J].Cryogenic Technology,2006,(6):24-28.
[13]宗航,刘应书,刘文海,等.微型单塔RPSA制氧工艺参数实验研究[J].气体分离,2005,(6):17-21.ZONG H,LIU Y S,LIU W H,et al.Experimental study on oxygen production parameters of micro single tower RPSA[J].Gas Separation,2005,(6):17-21.
[14]祝显强,刘应书,杨雄,等.吸附及解吸压力对快速变压吸附床内速度及循环性能的影响[J].北京科技大学学报,2016,38(7):993-1001.ZHU X Q,LIU Y S,YANG X,et al.Effect of adsorption and desorption pressure on the velocity and cycling performance of rapid pressure swing adsorption[J].Journal of University of Science and Technology Beijing,2016,38(7):993-1001.
[15]祝显强,刘应书,杨雄,等.中间气两步充压对快速真空变压吸附制氧的影响[J].化工学报,2016,67(10):4264-4272.ZHU X Q,LIU Y S,YANG X,et al.Effect of two-step pressurization with intermediate gas on rapid vacuum pressure swing adsorption process for oxygen generation[J].CIESC Journal,2016,67(10):4264-4272.
[16]祝显强,刘应书,焦璐璐,等.快速真空变压吸附制氧的排放气充压过程研究[J].北京科技大学学报,2015,37(11):1513-1519.ZHU X Q,LIU Y S,JIAO L L,et al.Study on pressurization with raffinate in a rapid vacuum pressure swing adsorption process for producing oxygen[J].Journal of University of Science and Technology Beijing,2015,37(11):1513-1519.
[17]TODD R S,WEBLEY P A.Mass-transfer models for rapid pressure swing adsorption simulation[J].AICh E Journal,2010,52(9):3126-3145.
[18]BAE Y S,LEE C H.Sorption kinetics of eight gases on a carbon molecular sieve at elevated pressure[J].Carbon,2005,43(1):95-107.
[19]BAE Y S,MOON J H,AHN H,et al.Effects of adsorbate properties on adsorption mechanism in a carbon molecular sieve[J].Korean Journal of Chemical Engineering,2004,21(3):712-720.
[20]LI D D,ZHOU Y,SHEN Y H,et al.Experiment and simulation for separating CO2/N2 by dual-reflux pressure swing adsorption process[J].Chemical Engineering Journal,2016,297:315-324.
[21]YAN H Y,FU Q,ZHOU Y,et al.CO2 capture from dry flue gas by pressure vacuum swing adsorption:a systematic simulation and optimization[J].International Journal of Greenhouse Gas Control,2016,51:1-10.
[22]YIN C B,SUN W N,YANG H W,et al.Optimization of three-bed VPSA system for biogas upgrading[J].Chemical Engineering Science,2015,135:100-108.
[23]周言,沈圆辉,付强,等.真空变压吸附分离CH4/N2/O2实验、模拟与安评[J].化工学报,2017,68(2):723-731.ZHOU Y,SHEN Y H,FU Q,et al.Experiment,simulation and safety evaluation of vacuum pressure swing adsorption for CH4/N2/O2separation[J].CIESC Journal,2017,68(2):723-731.
[24]杨彦钢,丁艳宾,马正飞,等.不同均压方式对PSA和VSA空分制氧过程的影响[J].南京工业大学学报(自然科学版),2012,34(4):79-83.YANG Y G,DING Y B,MA Z F,et al.Effects of different pressure equalization methods on PSA and VSA processes for O2 production from air[J].Journal of Nanjing University of Technology(Natural Science Edition),2012,34(4):79-83.
[25]RIPE R H.PERRY化学工程手册[M].北京:化学工业出版社,1992:149.RIPE R H.PERRY Chemical Engineering Handbook[M].Beijing:Chemical Industry Press,1992:149.
[26]BONIFACE H A,RUTHVEN D M.Chromatographic adsorption with sinusoidal input[J].Chemical Engineering Science,1985,40(11):2053-2061.
[27]周圆圆,韦向攀,张东辉.三塔真空变压吸附富氧工艺过程模拟[J].化工进展,2011,30(S2):263-267.ZHOU Y Y,WEI X P,ZHANG D H.Simulation of three-bed VPSA oxygen enriched process[J].Chemical Industry and Engineering Progress,2011,30(S2):263-267.
[28]李绍芬.反应工程[M].3版.北京:化学工业出版社,2013:167-171.LI S F.Reaction Engineering[M].3rd ed.Beijing:Chemical Industry Press,2013:167-171.
[29]北川浩.吸附的基础与设计[M].鹿政理,译.北京:化学工业出版社,1983:69-71.HIROSHI K.The Basis and Design of Adsorption[M].LU Z L,trans.Beijing:Chemical Industry Press,1983:69-71.
[30]RUTHVEN D M.Principles of Adsorption&Adsorption Processes[M].New York:John Wiley&Sons Inc.,1984:134-159.