Synergy in the hybrid thermochemical–biological processes for liquid fuel production

For a successful large scale implementation of biomass-to-liquid fuel for transportation, it is imperative that production of liquid fuel from biomass be maximized. For this purpose, synergistic processes using energy from sustainable carbon-free energy sources are needed. In this paper, we present such novel integrated processes that, when compared to the known conventional conversion methods, have potential to produce nearly three times more liquid fuel from a given quantity of biomass. The new processes treat biomass predominantly as carbon source and rely on the novel integrations to preserve carbon atoms during biomass conversion to liquid fuel. We have named such approach as hybrid hydrogen–carbon (H₂CAR) process. Furthermore, we propose a novel synergistic integration between H₂CAR and fermentation process where high-level heat from the H₂CAR process is used to supply process heat for the fermentation process and CO₂ produced during the fermentation is converted to liquid fuel using H₂CAR process. This synergy leads to increase in process carbon efficiency (100%) and higher energy efficiency (65.7% vs. 57.2%), significantly decreasing land area requirement to produce liquid fuel compared to fermentation-based processes. Such synergistically integrated processes provide attractive opportunities for process design, operation and control.