TY - JOUR
T1 - Regulating Phase Separation Behavior of a DEEA-TETA Biphasic Solvent Using Sulfolane for Energy-Saving CO2 Capture
AU - Wang, Lidong
AU - Liu, Shanshan
AU - Wang, Rujie
AU - Li, Qiangwei
AU - Zhang, Shihan
N1 - Funding Information:
This study was supported by the National Natural Science Foundation of China (nos. 21805084 and 21706061), Natural Science Foundation of Hebei Province (no. B2018502046), and Fundamental Research Funds for the Central Universities (nos. 2019MS110 and 2017MS137).
PY - 2019/11/5
Y1 - 2019/11/5
N2 - Biphasic solvents containing mixed amines have a phase separation behavior and energy-efficient regeneration for CO2 capture. However, the trade-off between the CO2 absorption capacity and the volume ratio of the CO2-rich phase presents a critical challenge to the reducing potential in regeneration energy consumption. In this study, sulfolane was proposed to regulate the phase separation behavior of a N,N-diethylethanolamine (DEEA)-triethylenetetramine (TETA) biphasic absorbent by simultaneously decreasing the volume ratio and increasing the CO2 loading of the rich phase, without sacrificing the high CO2 capacity. In the DEEA-TETA-sulfolane biphasic absorbent, sulfolane acted as a phase splitter and physical activator. The replacement of a part of H2O by hydrophobic sulfolane contributed to a substantial decrease in the volume ratio of the rich phase from 83 to 39% and an increase in CO2 loading of the rich phase from 3.10 to 4.92 mol/L. The regeneration heat decreased to 1.81 GJ/t CO2, 26.4% less than DEEA-TETA, and 54.6% less than the 5 M monoethanolamine system. Moreover, by promoting the mass transfer coefficient of CO2 in DEEA-TETA-sulfolane to 1.8 times the original DEEA-TETA system, sulfolane was validated as a physical activator. Our study provides a promising strategy for regulating the phase separation behavior of biphasic solvents and enhancing the regeneration energy efficiency for CO2 capture.
AB - Biphasic solvents containing mixed amines have a phase separation behavior and energy-efficient regeneration for CO2 capture. However, the trade-off between the CO2 absorption capacity and the volume ratio of the CO2-rich phase presents a critical challenge to the reducing potential in regeneration energy consumption. In this study, sulfolane was proposed to regulate the phase separation behavior of a N,N-diethylethanolamine (DEEA)-triethylenetetramine (TETA) biphasic absorbent by simultaneously decreasing the volume ratio and increasing the CO2 loading of the rich phase, without sacrificing the high CO2 capacity. In the DEEA-TETA-sulfolane biphasic absorbent, sulfolane acted as a phase splitter and physical activator. The replacement of a part of H2O by hydrophobic sulfolane contributed to a substantial decrease in the volume ratio of the rich phase from 83 to 39% and an increase in CO2 loading of the rich phase from 3.10 to 4.92 mol/L. The regeneration heat decreased to 1.81 GJ/t CO2, 26.4% less than DEEA-TETA, and 54.6% less than the 5 M monoethanolamine system. Moreover, by promoting the mass transfer coefficient of CO2 in DEEA-TETA-sulfolane to 1.8 times the original DEEA-TETA system, sulfolane was validated as a physical activator. Our study provides a promising strategy for regulating the phase separation behavior of biphasic solvents and enhancing the regeneration energy efficiency for CO2 capture.
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U2 - 10.1021/acs.est.9b02787
DO - 10.1021/acs.est.9b02787
M3 - Article
C2 - 31446756
AN - SCOPUS:85072637256
VL - 53
SP - 12873
EP - 12881
JO - Environmental Science and Technology
JF - Environmental Science and Technology
SN - 0013-936X
IS - 21
ER -