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Effects of reactor geometry on dissociating CO 2 and electrode degradation in a MHCD plasma reactor
Author(s) -
Taylan Onur,
Pinero Daniel,
Berberoglu Halil
Publication year - 2018
Publication title -
greenhouse gases: science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.45
H-Index - 32
ISSN - 2152-3878
DOI - 10.1002/ghg.1776
Subject(s) - electrode , dielectric , degradation (telecommunications) , dielectric barrier discharge , analytical chemistry (journal) , reaction rate constant , chemistry , chemical reactor , cathode , materials science , optoelectronics , chemical engineering , electrical engineering , kinetics , chromatography , physics , quantum mechanics , engineering
This paper reports an experimental study on the effects of reactor geometry for dissociating carbon dioxide using a microhollow cathode discharge (MHCD) reactor, and the associated electrode degradation. A MHCD reactor consists of two hollow metal electrodes that are separated by dielectric material. The geometric reactor parameters studied were the dielectric material thickness and the diameter of the reactor hole. Dielectric thicknesses of 150, 300 and 450 μm and discharge hole diameters of 200, 400 and 515 μm were studied parametrically. The results of each parameter combination were discussed in terms of specific energy input (SEI), CO 2 conversion, electrical‐to‐chemical energy conversion efficiency, and degradation rate of the electrodes. Overall, the results showed that, at constant SEI, increasing the dielectric thickness increased CO 2 conversion and energy efficiency but decreased the degradation rate. Moreover, at a constant SEI, varying the hole diameter did not affect CO 2 conversion or efficiency but the electrode degradation rate decreased with increasing hole diameter. The maximum efficiency observed was about 18.5% for the dielectric thickness of 450 μm, hole diameter of 400 μm, and a SEI of 0.1 eV/mol. With this reactor geometry, the maximum CO 2 conversion was 17.3% at a SEI of 3.7 eV/mol. Moreover, the results showed that the rate of electrode degradation increased linearly with time at a rate ranging from 130 to 207 μm 2 /s, with a reactor lifetime of 13 hours at a SEI of 3.7 eV/mol. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.