Thermodynamic analysis of the integrated Power to SNG system using heat from process gas and methanation reactor cooling to produce steam for solid oxide electrolyzer

Large-scale energy storage is increasingly important in the development of the energy sector in the context of diversification of energy sources and energy security. One of the promising energy storage technologies is power to SNG (PtSNG), which uses hydrogen that is converted to synthetic natural gas (SNG) in the methanation process. This article presents a thermodynamic analysis of an integrated PtSNG installation, using surplus electricity from the power grid generated in the valley of night demand. The installation includes a solid oxide electrolysis process for the production of hydrogen and a methanation unit for the production of synthetic natural gas, which uses gas from the biomass gasification as a source of carbon oxides. The heat generated within the PtG installation is used to supply the solid oxide electrolyzer (SOE). The simulation model of the analyzed installation, prepared in the Aspen Plus program, was used for the calculations. The estimated efficiency of the power to SNG system is equal 53.3%.