CIESC Journal ›› 2022, Vol. 73 ›› Issue (5): 1930-1939.DOI: 10.11949/0438-1157.20211767

• Fluid dynamics and transport phenomena • Previous Articles     Next Articles

Mass transfer characteristics of CO2 absorption in alkanolamine/ionic liquid hybrid aqueous solutions in a microchannel

Yaran YIN1(),Xingxing ZHU1,Xianming ZHANG1,Chunying ZHU2,Taotao FU2,Youguang MA2()   

  1. 1.National Engineering Laboratory for Textile Fiber Materials and Processing Technology, School of Materials Science and Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, Zhejiang, China
    2.State Key Laboratory of Chemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
  • Received:2021-12-14 Revised:2022-03-02 Online:2022-05-24 Published:2022-05-05
  • Contact: Youguang MA

微通道内醇胺/离子液体复配水溶液吸收CO2的传质特性

殷亚然1(),朱星星1,张先明1,朱春英2,付涛涛2,马友光2()   

  1. 1.纺织纤维材料与加工技术国家地方联合工程实验室,浙江理工大学材料科学与工程学院,浙江 杭州 310018
    2.化学工程联合国家重点实验室,天津大学化学工程学院,天津 300072
  • 通讯作者: 马友光
  • 作者简介:殷亚然(1990—),女,博士,讲师,yryin@zstu.edu.cn
  • 基金资助:
    浙江省自然科学基金项目(LQ21B060009);国家自然科学基金项目(22008220);浙江理工大学科研业务费专项(2021Q014)

Abstract:

The absorption performance of CO2 by blends of alkanolamines [monoethanolamine (MEA) and methyldiethanolamine (MDEA)] and ionic liquids [1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]) and 1-hydroxyethyl-3-methylimidazolium glycine ([C2OHmim][GLY])] was investigated in the microchannel. The influence of the concentration ratio of alkanolamine/ionic liquid (cAAcIL) on the liquid-phase volumetric mass transfer coefficient (kLa) was highlighted. The results show that kLa increases with the increase of reaction rate for all solutions. In order to further elucidate the mass transfer mechanism of CO2 absorption by the compound aqueous solution, the effects of specific surface area, diffusion rate, enhancement factor and liquid-elastic circulation on the mass transfer rate were analyzed. The results show that the overall mass transfer rate is significantly controlled by chemical reaction rate at low flow rates, and by circulation frequency (fcir) at high flow rates. Nevertheless, kLa can still be expressed as a mathematical function of fcir. kLa is linearly related with fcir at low gas flow rates, and the slope is positively related with the reaction rate. At high gas flow rates, the effect of circulation on mass transfer rate becomes weak due to the difficulty of film-slug exchange. In this case, kLa follows a power-law relation with fcir whose exponent is less than 1.

Key words: microchannels, alkanolamine, ionic liquid, gas-liquid flow, mass transfer

摘要:

研究了微通道内醇胺[单乙醇胺(MEA)和甲基二乙醇胺(MDEA)]与离子液体[1-丁基-3-甲基咪唑四氟硼酸([Bmim][BF4])和1-羟乙基-3-甲基咪唑甘氨酸([C2OHmim][GLY])]复配水溶液吸收CO2的传质特性。考察了醇胺/离子液体浓度比(cAAcIL)对液相体积传质系数(kLa)的影响,发现kLa随反应速率的增大而增大。为进一步阐释复配水溶液吸收CO2的传质机理,分析了比表面积、扩散速率、增强因子和液弹循环对传质速率的影响。结果表明,四种复配溶液中,反应速率和循环频率(fcir)分别在低流率和高流率下对传质速率起主导作用。kLa可表示为fcir的函数,低气相流率下kLafcir呈线性关系,斜率与反应速率成正相关,高气相流率下,液弹循环因膜弹传递困难而对整体传质速率的影响减弱,kLafcir呈指数关系,幂律指数小于1。

关键词: 微通道, 醇胺, 离子液体, 气液两相流, 传质

CLC Number: