Utilisation of Renewable Electricity to Produce Synthetic Methane

Abstract

This study demonstrates the production of synthetic methane or synthetic natural gas via methanation of carbon dioxide (CO2), which could replace natural gas. For the power-to-methane (P2M) process, a simulation of two-stage methanation with simultaneous power generation was carried out in Aspen Plus. The process is based on an assumed production capacity of 1 t/h of synthetic methane and is also capable of simultaneous methanation of CO2 and biogas. The biogas flow rate was estimated from industry data. When co-methanation is carried out, it is possible to produce up to 1.3 t/h of synthetic methane. After the production of synthetic methane, compression of the product was added to the process scheme, followed by dehydration. The dehydration of the synthetic methane was carried out via dynamic simulation in Aspen Adsorption. The steady-state operation was determined. The final dehydrated product contained on average only about 4.85 × 10−4 mol.% water (H2O) and the methane (CH4) contents were above 97 mol.%, providing a composition suitable for injection into the pipelines of many European countries.