Abstract
Greenhouse gaseous emissions have increased significantly, leading to implement carbon capture, utilisation and storage technology. Among potential carbon utilisation strategies, carbon dioxide (CO2) methanation received much attention due to the advantage of producing non-fossil fuel energy sources using CO2 captured from flue gas. However, CO2 methanation is a highly kinetic limited reaction, so a catalyst needs to be applied to achieve targeted reaction performance. In recent years, nickel-based catalysts have been widely used in catalysing the CO2 methanation process due to high activity and availability but utilising nickel-based catalysts will lead to a high activation energy of 92 kJ/mol for the reaction to occur so NEMR5-8, an in-house synthesised catalyst, was developed to lower the activation energy. This study developed a simulation model to investigate the improvement in CO2 conversion with respect to temperature, pressure, catalyst-to-feed ratio and net energy produced. Based on the simulation result, the NEMR5-8 catalyst required methanation to be operated at a low temperature of 100 °C to achieve 100 % conversion, which led to a 10 % energy intensity saving compared to the nickel-based catalyst. NEMR5-8 was also capable of withstanding change in pressure and maintained 100 % CO2 conversion at pressures of 1 to 5 bar and could enhance CO2 conversion for the methanation process at a low catalyst-to-feed ratio, 0.25 (1 kg catalyst).
