BioCORE - Thermodynamic evaluation of a biogas powered reversible SOC system

In this work the new BioCORE process is evaluated. BioCORE converts a continuously produced biogas (50% CH4, 50% CO2) stream in a Reversible Solid Oxide Cell (RSOC) system to produce either electricity or biomethane (=Synthetic Natural Gas; SNG), depending on the shortage or excess availability of electricity, for example from photovoltaic and wind power. The analysis is performed based on a RSOC model, which has been validated against experimental stack data, and further component models created in Aspen Plus. Different process designs are analyzed, which provide different amounts of purified excess CO2 for industrial purposes. The analysis also covers the heat and electricity demand of the biogas production, as well as gas cleaning. Furthermore, the effect of raising the operating pressures up to 15 bar is studied. Due to rigorous exergetic system optimization and cascaded heat integration, in combination with consumption of excess heat in a steam cycle, the process shows very high conversion efficiencies. At a SOC operating temperature of 765 °C and current density of 0.5 A/cm² in the “generation” mode (electricity production) the exergy efficiency reaches up to 80.6%. During “storage” mode operation (biogas upgrading by electrolysis and methanation) the current density is increased to 1 A/cm² for operating at thermo-neutral voltage, and an exergy efficiency of 85.9% is obtained.     «

In this work the new BioCORE process is evaluated. BioCORE converts a continuously produced biogas (50% CH4, 50% CO2) stream in a Reversible Solid Oxide Cell (RSOC) system to produce either electricity or biomethane (=Synthetic Natural Gas; SNG), depending on the shortage or excess availability of electricity, for example from photovoltaic and wind power. The analysis is performed based on a RSOC model, which has been validated against experimental stack data, and further component models...     »