Synthetic natural gas production from CO2 and renewable H2: Towards large-scale production of Ni–Fe alloy catalysts for commercialization

Abstract

Synthetic natural gas (SNG) is one of the promising energy carriers for the excessive electricity generated from variable renewable energy sources. SNG production from renewable H2 and CO2 via catalytic CO2 methanation has gained much attention since CO2 emissions could be simultaneously reduced. In this study, Ni–Fe/(Mg,Al)Ox alloy catalysts for CO2 methanation were prepared via hydrotalcite precursors using a rapid coprecipitation method. The effect of total metal concentration on the physicochemical properties and catalytic behavior was investigated. Upon calcination, the catalysts showed high specific surface area of above 230 m2 g−1. Small particle sizes of about 5 nm were obtained for all catalysts, even though the produced catalyst amount was increased by 10 times. The catalysts exhibited excellent space-time yield under very high gas space velocity (34,000 h−1), irrespective of the metal concentration. The CO2 conversions reached 73–79% at 300 °C and CH4 selectivities were at 93–95%. Therefore, we demonstrated the potential of large-scale production of earth-abundant Ni–Fe based catalysts for CO2 methanation and the Power-to-Gas technology.