Publication
Title
Inhibiting recombination to improve the performance of plasma-based CO₂ conversion
Author
Abstract
Warm plasma offers a promising route for CO2 splitting into valuable CO, yet recombination reactions of CO with oxygen, forming again CO2, have recently emerged as critical limitation. This study combines experiments and fluid dynamics + chemical kinetics modelling to comprehensively analyse the recombination reactions upon CO2 splitting in an atmospheric plasmatron. We introduce an innovative in-situ gas sampling technique, enabling 2D spatial mapping of gas product compositions and temperatures, experimentally confirming for the first time the substantial limiting effect of CO recombination reactions in the afterglow region. Our results show that the CO mole fraction at a 5 L/min flow rate drops significantly from 11.9 % at a vertical distance of z = 20 mm in the afterglow region to 8.6 % at z = 40 mm. We constructed a comprehensive 2D model that allows for spatial reaction rates analysis incorporating crucial reactions, and we validated it to kinetically elucidate this phenomenon. and are the dominant reactions, with the forward reactions prevailing in the plasma region and the backward reactions becoming prominent in the afterglow region. These results allow us to propose an afterglow quenching strategy for performance enhancement, which is further demonstrated through a meticulously developed plasmatron reactor with two-stage cooling. Our approach substantially increases the CO2 conversion (e.g., from 6.6 % to 19.5 % at 3 L/min flow rate) and energy efficiency (from 13.5 % to 28.5 %, again at 3 L/min) and significantly shortens the startup time (from ∼ 150 s to 25 s). Our study underscores the critical role of inhibiting recombination reactions in plasma-based CO2 conversion and offers new avenues for performance enhancement.
Language
English
Source (journal)
Chemical engineering journal. - Lausanne, 1996, currens
Publication
Lausanne : Elsevier Sequoia , 2024
ISSN
1385-8947 [print]
1873-3212 [online]
DOI
10.1016/J.CEJ.2024.148684
Volume/pages
481 (2024) , p. 1-31
Article Reference
148684
ISI
001168999200001
Full text (Publisher's DOI)
Full text (open access)
The author-created version that incorporates referee comments and is the accepted for publication version Available from 19.07.2024
Full text (publisher's version - intranet only)
UAntwerpen
Faculty/Department
Research group
Project info
Modeling-based design of a rotating gliding arc plasmatron with gas quenching and heat recovery for conversion of CO2, CH4 and H2O
Surface-COnfined fast-modulated Plasma for process and Energy intensification in small molecules conversion (SCOPE).
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identifier
Creation 13.03.2024
Last edited 02.04.2024
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