Flexible biomass conversion to methanol integrating solid oxide cells and TwoStage gasifier
Abstract
Synthetic fuels produced from carbonaceous sources and renewable electricity can play an important role in phasing out fossil fuels. By integrating electricity in fuel production, an indirect electrification of long-distance sea, air and road transport becomes feasible. This paper presents the modeling analysis of a flexible system for the conversion of biomass and electricity to methanol. The system integrates an efficient TwoStage biomass gasifier and solid oxide cells (SOC). The SOC can operate in both electrolysis mode and fuel cell mode. In this way, the system can store electricity in the form of methanol in electrolysis mode or have co-production of electricity in fuel cell mode. Additional operational modes are also presented, making it feasible to operate the system no matter the electricity price. The heat for the endothermic gasification reactions is provided either through electric heating or partial oxidation directly in the char fluid bed gasifier. Five operating modes have been modeled and analyzed, showing a promising input–output efficiency ranging between 71% with maximum electricity consumption, and 37% when producing only electricity (LHVdry). The presented system outperforms most of the more conventional state-of-the-art systems using biomass gasification as route to produce methanol. Most importantly, its flexibility enables continuous operation no matter the electricity price.