Kinetic studies of CO2 methanation over a Ni/γ-Al2O3 catalyst using a batch reactor. (17th February 2016)

• Record Type: Journal Article
• Authors: Yang Lim, Jin; McGregor, J.; Sederman, A.J.; Dennis, J.S.
• Is Part Of: Chemical engineering science. Volume 141(2016)
• Page Start: 28
• Page End: 45
• Publication Date: 2016-02-17
• Subjects: Methanation of CO2 -- Kinetic measurements -- Nickel/alumina catalyst -- Modelling; Chemical engineering -- Periodicals; Génie chimique -- Périodiques; Chemical engineering; Periodicals; Electronic journals; 660
• DOI: 10.1016/j.ces.2015.10.026
• Languages: English
• ISSNs: 0009-2509

Abstract

Abstract: The methanation of CO2 was investigated over a wide range of partial pressures of products and reactants using a gradientless, spinning-basket reactor operated in batch mode. The rate and selectivity of CO2 methanation, using a 12 wt% Ni/ γ –Al2 O3 catalyst, were explored at temperatures 453–483 K and pressures up to 20 bar. The rate was found to increase with increasing partial pressures of H2 and CO2 when the partial pressures of these reactants were low; however, the rate of reaction was found to be insensitive to changes in the partial pressures of H2 and CO2 when their partial pressures were high. A convenient method of determining the effect of H2 O on the rate of reaction was also developed using the batch reactor and the inhibitory effect of H2 O on CO2 methanation was quantified. The kinetic measurements were compared with a mathematical model of the reactor, in which different kinetic expressions were explored. The kinetics of the reaction were found to be consistent with a mechanism in which adsorbed CO2 dissociated to adsorbed CO and O on the surface of the catalyst with the rate-limiting step being the subsequent dissociation of adsorbed CO. Highlights: CO2 methanation investigated in a spinning-basket reactor operated in batch. Rate and selectivity determined for 12 wt% Ni/ γ Al2 O3 catalyst, 453–483 K to 20 bar. Convenient method of determining the effect of H2 O on the rate was developed. Kinetics were consistent with adsorbed CO2 dissociating to adsorbed CO and O. The RDS is the subsequent dissociation of adsorbed CO.