Home | << 1 >> |
![]() |
Records | |||||
---|---|---|---|---|---|
Author | Uytdenhouwen, Y.; Bal, Km.; Michielsen, I.; Neyts, Ec.; Meynen, V.; Cool, P.; Bogaerts, A. | ||||
Title | How process parameters and packing materials tune chemical equilibrium and kinetics in plasma-based CO2 conversion | Type | A1 Journal article | ||
Year | 2019 | Publication | Chemical engineering journal | Abbreviated Journal | Chem Eng J |
Volume | 372 | Issue | Pages | 1253-1264 | |
Keywords | A1 Journal article; Laboratory of adsorption and catalysis (LADCA); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | Plasma (catalysis) reactors are increasingly being used for gas-based chemical conversions, providing an alternative method of energy delivery to the molecules. In this work we explore whether classical concepts such as equilibrium constants, (overall) rate coefficients, and catalysis exist under plasma conditions. We specifically investigate the existence of a so-called partial chemical equilibrium (PCE), and how process parameters and packing properties influence this equilibrium, as well as the overall apparent rate coefficient, for CO2 splitting in a DBD plasma reactor. The results show that a PCE can be reached, and that the position of the equilibrium, in combination with the rate coefficient, greatly depends on the reactor parameters and operating conditions (i.e., power, pressure, and gap size). A higher power, higher pressure, or smaller gap size enhance both the equilibrium constant and the rate coefficient, although they cannot be independently tuned. Inserting a packing material (non-porous SiO2 and ZrO2 spheres) in the reactor reveals interesting gap/material effects, where the type of material dictates the position of the equilibrium and the rate (inhibition) independently. As a result, no apparent synergistic effect or plasma-catalytic behaviour was observed for the non-porous packing materials studied in this reaction. Within the investigated parameters, equilibrium conversions were obtained between 23 and 71%, while the rate coefficient varied between 0.027 s−1 and 0.17 s−1. This method of analysis can provide a more fundamental insight in the overall reaction kinetics of (catalytic) plasma-based gas conversion, in order to be able to distinguish plasma effects from true catalytic enhancement. |
||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000471670400116 | Publication Date | 2019-05-08 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1385-8947 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.216 | Times cited | 3 | Open Access | Not_Open_Access: Available from 05.05.2021 |
Notes | European Fund for Regional Development; FWOFWO, G.0254.14N ; University of Antwerp; FWO-FlandersFWO-Flanders, 11V8915N ; The authors acknowledge financial support from the European Fund for Regional Development through the cross-border collaborative Interreg V program Flanders-the Netherlands (project EnOp), the Fund for Scientific Research (FWO; Grant Number: G.0254.14N), a TOP-BOF project and an IOF-SBO (SynCO2Chem) project from the University of Antwerp. K. M. B. was funded as a PhD fellow (aspirant) of the FWOFlanders (Fund for Scientific Research-Flanders), Grant 11V8915N. | Approved | Most recent IF: 6.216 | ||
Call Number | PLASMANT @ plasmant @UA @ admin @ c:irua:159979 | Serial | 5171 | ||
Permanent link to this record | |||||
Author | Uytdenhouwen, Y.; Bal, Km.; Neyts, Ec.; Meynen, V.; Cool, P.; Bogaerts, A. | ||||
Title | On the kinetics and equilibria of plasma-based dry reforming of methane | Type | A1 Journal article | ||
Year | 2021 | Publication | Chemical Engineering Journal | Abbreviated Journal | Chem Eng J |
Volume | 405 | Issue | Pages | 126630 | |
Keywords | A1 Journal article; Laboratory of adsorption and catalysis (LADCA); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
Abstract | Plasma reactors are interesting for gas-based chemical conversion but the fundamental relation between the plasma chemistry and selected conditions remains poorly understood. Apparent kinetic parameters for the loss and formation processes of individual components of gas conversion processes, can however be extracted by performing experiments in an extended residence time range (2–75 s) and fitting the gas composition to a firstorder kinetic model of the evolution towards partial chemical equilibrium (PCE). We specifically investigated the differences in kinetic characteristics and PCE state of the CO2 dissociation and CH4 reforming reactions in a dielectric barrier discharge reactor (DBD), how these are mutually affected when combining both gases in the dry reforming of methane (DRM) reaction, and how they change when a packing material (non-porous SiO2) is added to the reactor. We find that CO2 dissociation is characterized by a comparatively high reaction rate of 0.120 s−1 compared to CH4 reforming at 0.041 s−1; whereas CH4 reforming reaches higher equilibrium conversions, 82% compared to 53.6% for CO2 dissociation. Combining both feed gases makes the DRM reaction to proceed at a relatively high rate (0.088 s−1), and high conversion (75.4%) compared to CO2 dissociation, through accessing new chemical pathways between the products of CO2 and CH4. The addition of the packing material can also distinctly influence the conversion rate and position of the equilibrium, but its precise effect depends strongly on the gas composition. Comparing different CO2:CH4 ratios reveals the delicate balance of the combined chemistry. CO2 drives the loss reactions in DRM, whereas CH4 in the mixture suppresses back reactions. As a result, our methodology provides some of the insight necessary to systematically tune the conversion process. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000621197700003 | Publication Date | 2020-08-12 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1385-8947 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 6.216 | Times cited | Open Access | OpenAccess | |
Notes | The authors acknowledge financial support from the European Fund for Regional Development through the cross-border collaborative Interreg V program Flanders-the Netherlands (project EnOp), the Fund for Scientific Research (FWO; grant number: G.0254.14N), a TOP-BOF project and an IOF-SBO (SynCO2Chem) project from the University of Antwerp. | Approved | Most recent IF: 6.216 | ||
Call Number | PLASMANT @ plasmant @c:irua:172458 | Serial | 6411 | ||
Permanent link to this record |