Flexible methanol production units coupling solid oxide cells and thermochemical biomass conversion via different gasification technologies

Abstract

Thermochemical conversion of biomass is a promising option to produce energy-dense liquid biofuels, aiming to phase out fossil fuels from the transportation sector. Integration of renewable electricity boosts biofuel yield and carbon conversion from the scarce biomass resource, creating an indirect electrification of the transportation sector. Coupling biomass gasification and solid oxide cells (SOC), able to run in both electrolysis and fuel cell mode, constitutes the framework for flexible biofuel production. This paper compares the performance of five novel plant configurations for flexible biomass conversion to methanol and power. The plant performance is evaluated at five different operation modes: high production of methanol at low/intermediate electricity prices, co-production of electricity and methanol at high prices, and production of electricity without methanol co-production at price peaks. A TwoStage gasifier, a bubbling fluidized bed and an entrained flow gasifier are chosen as gasification technologies. The systems are thermodynamically modeled, and analyzed in terms of efficiency and carbon conversion. The highest efficiencies are achieved with the systems based on TwoStage Electro-gasifier (71%) and entrained flow gasification with pyrolysis as fuel pre-treatment (72%). The flexibility achieved by this technology combination enables high capacity factors, important for an accelerated commercialization of thermochemical biomass conversion.