Integration of Power-to-Gas in Gasendal and GoBiGas

Abstract

Power-to-Gas, which is the term used to describe the use of electrolysis and Sabatier reactor systems to react H2 and CO2 and form CH4, is a technology that has received a great deal of attention recently. The produced CH4 can be used in a variety of applications, including fuel for vehicles and energy storage in existing natural gas networks. Research is currently being conducted on the performance of this technology, and several demonstration plants have been built. However, few evaluations have been made on the implementation of power-to-gas in existing biogas production plants. This thesis will look at the technical and economic aspects involved in integrating the power-to-gas technology in a biomass gasification plant (GoBiGas) and a biogas upgrading plant (Gasendal). The technical evaluation is carried out using the process engineering software Aspen Plus. The Sabatier reactor system is modelled and optimized with regard to material and reactant composition restrictions, and Pinch analysis is carried out to evaluate the potential for heat recovery. An economic evaluation is made to check the profitability of the implementation with respect to current energy market conditions, and a sensitivity analysis is done to conclude what future market changes and technology conditions may affect the economic outcome. In conclusion, the implementation of power-to-gas is profitable for neither of the two applications with current market and technology conditions. However, investment costs are predicted to fall and SNG prices are likely to rise in the future, which would benefit the economic outcome of the implementation.