Systematic study of an energy efficient MEA-based electrochemical CO2 capture process: From mechanism to practical application

Applied Energy，Volume 327, 1 December 2022, 120014

XiaomeiWuHuifengFanYuanhaoMaoMaimoonaSharifYunsongYuZaoxiaoZhangGuangxinLiu

Highlights

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An energy efficient MEA-based electrochemical CO₂ capture process was proposed.

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A systematic study of the copper ions redox reactions in EMAR have been done.

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MEA oxidative degradation in EMAR is discussed by electrochemical mechanism.

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A suitable current density and disturbance are beneficial to improve EMAR system.

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Regeneration energy is extremely competitive with traditional CO₂ capture methods.

 

Abstract

Electrochemically-mediated amine regeneration (EMAR) is a promising technology for CO₂ capture, especially in industries where thermal energy is not available. However, the EMAR technology is still at an early stage for commercial application because of its energy-intensive, operating at impractically low current densities, kinetically slow or amine degradation. To solve these problems, we report an energy efficient MEA-based electrochemical CO₂ capture process. The redox of copper is the fundamental step in the EMAR process, which determines the energy consumption, energy efficiency and cycling performance of the whole system. A systematic study of the redox reactions of copper ions and the effect of other mediums have been comprehensively studied in this work. Besides, amine oxidative degradation in EMAR has been firstly discussed from the perspective of the solution electrochemical mechanism. Moreover, the copper cycling performance and energy consumption of the proposed system have been carefully studied, results show that a suitable current density and appropriate disturbance are beneficial to improve the circulation performance of the system. The regeneration energy consumption is 60.76 kJ/mol CO₂, with a current density of 0.02 A/cm² and stirring speed of 200 rpm, which is extremely competitive to be used in CO₂ capture compared with traditional CO₂ chemical absorption methods.