Pure methane from CO2 hydrogenation using a sorption enhanced process with catalyst/zeolite bifunctional materials

Methanation is a potential large-scale option for CO2 utilization, and it is one of the solutions for decreasing carbon emission and production of synthetic green fuels. However, the CO2 conversion is limited by thermodynamics in conventional reaction conditions. However, around 100 % conversion can be obtained using sorption enhanced CO2 methanation according to Le Chatelier's principle, where water is removed during the reaction using zeolite as a sorbent. In this work 5%Ni5A, 5%Ni13X, 5%NiL and 5%Ni2.5%Ce13X bifunctional materials with both catalytic and water adsorption properties were tested in a fixed bed reactor. The overall performance of the bifunctional materials decreased on going from 5%Ni2.5%Ce13X, 5%Ni13X, 5%Ni5A, to 5% NiL. The CO2 conversion and CH4 selectivity were approaching 100 % during prolonged stability testing in a 100 reactive adsorption - desorption cycles test for 5%Ni2.5%Ce13X, and only a slight decrease of the water uptake capacity was observed.