Zeolite catalyst-aided tri-solvent blend amine regeneration: An alternative pathway to reduce the energy consumption in amine-based CO2 capture process. (15th April 2019)

• Record Type: Journal Article
• Authors: Zhang, Xiaowen; Huang, Yufei; Gao, Hongxia; Luo, Xiao; Liang, Zhiwu; Tontiwachwuthikul, Paitoon
• Is Part Of: Applied energy. Volume 240(2019)
• Page Start: 827
• Page End: 841
• Publication Date: 2019-04-15
• Subjects: CO2 capture -- Solid acid catalyst -- Catalytic CO2 desorption -- Tri-solvent blend amines -- Energy reduction; Power (Mechanics) -- Periodicals; Energy conservation -- Periodicals; Energy conversion -- Periodicals; 621.042
• DOI: 10.1016/j.apenergy.2019.02.089
• Languages: English
• ISSNs: 0306-2619

Abstract

Highlights: The MEA-MDEA-PZ tri-blend presented higher CO2 desorption activity than MEA. Easy proton transfer and rich bicarbonate led to the superior activity of blend. The combination of Hβ catalyst with blend amines decreased the heat duty by 66.1%. A plausible catalytic blend amines solvent regeneration mechanism was proposed. Structure-activity relations of zeolite catalyst for CO2 desorption was clarified. Abstract: The extensive energy penalty of CO2 -loaded solution regeneration is one of the most crucial challenges facing industrial application of amine-based CO2 capture technology. Here, to decrease the energy requirement, the regeneration behaviors of the rich 5 M monoethanolamine (MEA) and 3 M MEA-2.5 M N-methyl-diethanolamine (MDEA)−0.5 M piperazine (PZ) tri-solvent blended amines (tri-blend) with four different solid acid catalysts (H-mordenite, Hβ, HZSM-5 and Al2 O3 ) were studied at 98 °C. For the catalyst-free tests, the results revealed that the tri-blend hugely enhanced the CO2 desorption kinetics and reduced the relative energy consumption compared to 5 M MEA. Based on the results of 13 C NMR, the multiple proton transfer paths and abundant bicarbonate ions in the tri-blend contribute to the improved regeneration performance. Additionally, the use of catalyst further improved the CO2 desorption activity of the tri-blend. The combination of Hβ and tri-blend presented the best regeneration performance, increasing the desorption performance by 1360.8%, and reducing the relative energy requirement by 66.1% compared with the blank run of MEA. In addition, a plausible catalytic mechanism of solvent regeneration over the solid acid catalyst in the tri-blend was suggested. The superior catalytic performance of Hβ resulted from the large mesoporous surface area, larger number of Brϕnsted acid sites and prominent total acid sites. Furthermore, Hβ displayed excellent stability and had no adverse influence on the CO2 absorption activity. Results herein manifest that the combination of tri-blend amines with high-efficiency catalyst is exceptional strategy for tremendously decreasing the energy consumption of amine-based CO2 capture processes, ultimately making this technology more technically and economically feasible.