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Journal article
Electrolytic Regeneration of Spent Caustic Soda from CO2 Capture Systems
Processes, Vol.12(4), 723
2024
Abstract
The traditional electrochemical caustic soda recovery system uses the generated pH gradient across the ion exchange membrane for the regeneration of spent alkaline absorbent from CO 2 capture. This electrochemical CO 2 capture system releases the by-products H 2 and O 2 at the cathode and anode, respectively. Although effective for capturing CO 2 , the slow kinetics of the oxygen evolution reaction (OER) limit the energy efficiency of this technique. Hence, this study proposed and validated a hybrid electrochemical cell based on the H 2-cycling from the cathode to the anode to eliminate the reliance on anodic oxygen generation. The results show that our lab-scale prototype enabled effective spent caustic soda recovery with an electron utilisation efficiency of 90%, and a relative carbonate/bicarbonate diffusional flux of approximately 40%. The system also enabled the regeneration of spent alkaline absorbent with a minimum electrochemical energy input of 0.19 kWh/kg CO 2 at a CO 2 recovery rate of 0.7 mol/m 2 /h, accounting for 30% lower energy demand than a control system without H 2-recycling, making this technique a promising alternative to the conventional thermal regeneration technology.
Details
- Title
- Electrolytic Regeneration of Spent Caustic Soda from CO2 Capture Systems
- Authors/Creators
- H. Mohammadpour - Murdoch UniversityAlmantas PivrikasKa Yu Cheng - Commonwealth Scientific and Industrial Research OrganisationGoen Ho
- Publication Details
- Processes, Vol.12(4), 723
- Publisher
- MDPI
- Identifiers
- 991005649464307891
- Copyright
- © 2024 by the authors.
- Murdoch Affiliation
- Murdoch University
- Language
- English
- Resource Type
- Journal article
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