Selective methanation of CO in the presence of CO2 in hydrogen-containing mixtures on nickel catalysts

The screening of commercial nickel catalysts for methanation and a series of nickel catalysts supported on CeO2, γ-Al2O3, and ZrO2 in the reaction of selective CO methanation in the presence of CO2 in hydrogen-containing mixtures (1.5 vol % CO, 20 vol % CO2, 10 vol % H2O, and the balance H2) was performed at the flow rate WHSV = 26000 cm3 (g Cat)−1 h−1. It was found that commercial catalytic systems like NKM-2A and NKM-4A (NIAP-07-02) were insufficiently effective for the selective removal of CO to a level of <100 ppm. The most promising catalyst is 2 wt % Ni/CeO2. This catalyst decreased the concentration of CO from 1.5 vol % to 100 ppm in the presence of 20 vol % CO2 in the temperature range of 280–360°C at a selectivity of >40%, and it retained its activity even after contact with air. The minimum outlet CO concentration of 10 ppm at 80% selectivity on a 2 wt % Ni/CeO2 catalyst was reached at a temperature of 300°C.