THERMOGRAVIMETRIC AND SPECTROSCOPIC STUDIES OF CARBON DEPOSITED ON SBA-15 SUPPORTED NICKEL (Ni) CATALYST DURING CARBON DIOXIDE (CO2) REFORMING OF METHANE
Authors: *Omoregbe O, Ihoeghian N.A, Edokpayi O, Ossai J.E, Awelenje Q.A
The heterogeneity and amount of carbon deposited on Santa Barbara Amorphous-15 (SBA-15) supported Nickel (Ni) catalyst synthesised by incipient wetness impregnation method during carbon dioxide (CO2) reforming of methane (CH4) have been studied. The reforming process was performed in a fixed-bed tubular quartz reactor at 1023 K for up to 240 min under atmospheric pressure, and with varying CO2/CH4 feed ratios of 1:1–3:1 and 1:1–1:3, respectively. The activity of Ni catalyst was found to be influenced by the reactant’s feed ratios. An increase in CO2/CH4 feed ratio positively affected CH4 conversion whilst a steady drop in CO2 conversion was observed. On the other hand, H2 yield declined with increase in CO2/CH4 feed ratio, and CO yield increased, indicating the occurrence of side reactions such as reverse water-gas shift, and carbon gasification reactions. When the amount of CH4 in the feed was raised above the stoichiometric value, a rapid deactivation of the catalyst was observed. Post-characterization analysis of the spent catalysts revealed that carbon deposition was directly proportional to reactant’s feed ratio. Evidently, the least amount of carbon was observed at CO2/CH4 ratio of 2.5:1 while coke formation was greatly favoured at higher CH4 composition in the feed.
Affiliations: *Department of Chemical Engineering, University of Benin, PMB 1154, Benin City, Edo State, Nigeria.
Keywords: Boudouard Reaction, Ni/SBA-15, Gasification, Catalyst Decay, Silanol Group
Published date: 2018/06/30