Integrated power and gas system from biomass based on water electrolysis and CO2 methanation

Abstract

Based on biogas production, biomass thermal power generation, solid oxide electrolytic cell (SOEC), and biogas methanation, the simulation of biomass integrated power and gas system and the analysis of energy supply and demand relationship were realized by using energy and substance balance models. The results show that SOEC is coupled with methanation and thermal power generation with heat exchange, and the energy conversion efficiency of the system is 25.73%. The different utilizations of dry and wet biomass are conducive to improving overall energy efficiency. The oxygen by-product from SOEC can improve the efficiency of thermal power generation, and the decrease in the condensation temperature and pressure of spent steam benefits improving the power generation efficiency. The selection of biomass with high calorific value and low hydrogen-to-carbon ratio is conducive to improving energy conversion efficiency. Combined with energy storage, the conventional power and gas demand of residents can be realized, a negative correlation exists between the power and gas storage, and a decrease in the power storage will lead to SOEC working at high or low loads.