Innovative Synthetic Natural Gas Production from Biomass and Renewable Hydrogen: Evaluation and Optimization with Sustainability Perspective

Synthetic natural gas has a promising potential to contribute in sustainable supply of the natural gas and mitigating the intermittence issue of renewable energy sources. This study presents a novel system for synthetic natural gas production from biomass and renewable electrolytic hydrogen. A novel biomass and renewable electricity driven synthetic natural gas production system is presented. Hydrogen, an important input of the system, is supplied by biomass gasification and water electrolysis driven by renewable energy. Integrated system of photovoltaic panels and wind turbines supplies the required electricity of the system. An oxygen-steam mix is utilized as the gasification agent. An ion transport membrane is employed for oxygen production as an alternative to an expensive and complicated air separation unit. A comprehensive thermodynamic and economic analysis of the system is carried out. All equipment and ancillary costs are considered. Since solid carbon generation can lead to deactivation of the methanation reactor catalysts, the potential for solid carbon generation is considered for practicality. Multi-objective optimizations of different scenarios, are performed to determine the optimal economical and technical performance of the system. The optimization results indicate that the minimum cost for producing synthetic natural gas is 0.28 $/kWh. Furthermore, the heating value of synthetic natural gas is 41,500 kJ/kg, which closely approximates that of natural gas. Additionally, the price of the produced synthetic natural gas is lower than the price of natural gas in certain countries. In Sweden and the Netherlands, synthetic natural gas costs are notably 36% and 10% lower than conventional natural gas. However, in Germany, Austria, and Denmark, synthetic natural gas prices closely align with conventional natural gas rates, reflecting regional market variations.