Performance of Ni/Si‐MCM‐41 catalysts in CO₂ methanation

Abstract

The production of methane from the methanation reaction between H2 and CO2, also known as the Sabatier reaction, is one way to diversify the global energy matrix, providing a use for CO2. This work evaluates the performance in this reaction of Ni catalysts supported on type MCM‐41 silica, synthesized y a wet impregnation method. Catalytic tests were performed for 2.5 h under atmospheric pressure. The reaction variables considered were the catalyst nickel mass content (5% and 10%), temperature (T = 400 and 550°C), reactant ratio (H2/CO2 = 4 and 2.5), and space velocity (VHSV = 5 and 10 L g−1 h−1). The catalysts were characterized by Brunauer–Emmett–Teller (BET), X‐ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive x‐ray spectroscopy (EDS) analyses before the reactions, and by thermogravimetric analysis (TGA), SEM, and EDS analyses after the reactions. The reaction variables were evaluated using an experimental design with 2 factors and 4 variables, in order to determine the effects of the reaction conditions on catalyst selectivity, reactant conversion, and reaction yields in terms of CH4 and CO. The best result was obtained using a reactant ratio of 2.5, space velocity of 5 L g−1 h−1, and reaction temperature of 550°C, resulting in 93.7% selectivity for methane, 69.4% CO2 conversion, 74% H2 conversion, and methane yield of 20.69%. Findings show Ni/Si‐MCM‐41 catalyst's applicability in methanation, advancing CH4 production technology, and addressing local demand while reducing CO2 emissions.