SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2018, Vol. 26 ›› Issue (11): 2351-2360.DOI: 10.1016/j.cjche.2018.04.014

• Special issue of Carbon Capture, Utilisation and Storage • 上一篇    下一篇

The CO2 absorption and desorption performance of the triethylenetetramine + N,N-diethylethanolamine + H2O system

Yaoyao Li1,2, Changjun Liu1, Richard Parnas3, Yingying Liu2, Bin Liang1,2, Houfang Lu1,2   

  1. 1 School of Chemical Engineering, Sichuan University, Chengdu 610065, China;
    2 Institute of New Energy and Low Carbon Technology, Sichuan University, Chengdu 610207, China;
    3 Institute of Materials Science, University of Connecticut, Storrs, CT 06269-3136, USA
  • 收稿日期:2017-11-12 修回日期:2018-03-19 出版日期:2018-11-28 发布日期:2018-12-10
  • 通讯作者: Houfang Lu
  • 基金资助:

    Supported by the National Natural Science Foundation of China (21606154).

The CO2 absorption and desorption performance of the triethylenetetramine + N,N-diethylethanolamine + H2O system

Yaoyao Li1,2, Changjun Liu1, Richard Parnas3, Yingying Liu2, Bin Liang1,2, Houfang Lu1,2   

  1. 1 School of Chemical Engineering, Sichuan University, Chengdu 610065, China;
    2 Institute of New Energy and Low Carbon Technology, Sichuan University, Chengdu 610207, China;
    3 Institute of Materials Science, University of Connecticut, Storrs, CT 06269-3136, USA
  • Received:2017-11-12 Revised:2018-03-19 Online:2018-11-28 Published:2018-12-10
  • Contact: Houfang Lu
  • Supported by:

    Supported by the National Natural Science Foundation of China (21606154).

摘要: Post-combustion CO2 capture (PCC) process faces significant challenge of high regeneration energy consumption. Biphasic absorbent is a promising alternative candidate which could significantly reduce the regeneration energy consumption because only the CO2-concentrated phase should be regenerated. In this work, aqueous solutions of triethylenetetramine (TETA) and N,N-diethylethanolamine (DEEA) are found to be efficient biphasic absorbents of CO2. The effects of the solvent composition, total amine concentration, and temperature on the absorption behavior, as well as the effect of temperature on the desorption behavior of TETA-DEEA-H2O system were investigated. An aqueous solution of 1 mol·L-1 TETA and 4 mol·L-1 DEEA spontaneously separates into two liquid phases after a certain amount of CO2 is absorbed and it shows high CO2 absorption/desorption performance. About 99.4% of the absorbed CO2 is found in the lower phase, which corresponds to a CO2 absorption capacity of 3.44 mol·kg-1. The appropriate absorption and desorption temperatures are found to be 30℃ and 90℃, respectively. The thermal analysis indicates that the heat of absorption of the 1 mol·L-1 TETA and 4 mol·L-1 DEEA solution is -84.38 kJ·(mol CO2)-1 which is 6.92 kJ·(mol CO2)-1 less than that of aqueous MEA. The reaction heat, sensible heat, and the vaporization heat of the TETA-DEEA-H2O system are lower than that of the aqueous MEA, while its CO2 capacity is higher. Thus the TETA-DEEA-H2O system is potentially a better absorbent for the post-combustion CO2 capture process.

关键词: CO2 capture, Post-combustion, Amine mixtures, Biphasic absorbent

Abstract: Post-combustion CO2 capture (PCC) process faces significant challenge of high regeneration energy consumption. Biphasic absorbent is a promising alternative candidate which could significantly reduce the regeneration energy consumption because only the CO2-concentrated phase should be regenerated. In this work, aqueous solutions of triethylenetetramine (TETA) and N,N-diethylethanolamine (DEEA) are found to be efficient biphasic absorbents of CO2. The effects of the solvent composition, total amine concentration, and temperature on the absorption behavior, as well as the effect of temperature on the desorption behavior of TETA-DEEA-H2O system were investigated. An aqueous solution of 1 mol·L-1 TETA and 4 mol·L-1 DEEA spontaneously separates into two liquid phases after a certain amount of CO2 is absorbed and it shows high CO2 absorption/desorption performance. About 99.4% of the absorbed CO2 is found in the lower phase, which corresponds to a CO2 absorption capacity of 3.44 mol·kg-1. The appropriate absorption and desorption temperatures are found to be 30℃ and 90℃, respectively. The thermal analysis indicates that the heat of absorption of the 1 mol·L-1 TETA and 4 mol·L-1 DEEA solution is -84.38 kJ·(mol CO2)-1 which is 6.92 kJ·(mol CO2)-1 less than that of aqueous MEA. The reaction heat, sensible heat, and the vaporization heat of the TETA-DEEA-H2O system are lower than that of the aqueous MEA, while its CO2 capacity is higher. Thus the TETA-DEEA-H2O system is potentially a better absorbent for the post-combustion CO2 capture process.

Key words: CO2 capture, Post-combustion, Amine mixtures, Biphasic absorbent