Sustainable fuel for the transportation sector

Abstract

A hybrid hydrogen-carbon (H₂CAR) process for the production of liquid hydrocarbon fuels is proposed wherein biomass is the carbon source and hydrogen is supplied from carbon-free energy. To implement this concept, a process has been designed to co-feed a biomass gasifier with H₂ and CO₂ recycled from the H₂-CO to liquid conversion reactor. Modeling of this biomass to liquids process has identified several major advantages of the H₂CAR process. (i) The land area needed to grow the biomass is ii) Whereas the literature estimates known processes to be able to produce ≈30% of the United States transportation fuel from the annual biomass of 1.366 billion tons, the H₂CAR process shows the potential to supply the entire United States transportation sector from that quantity of biomass. (iii) The synthesized liquid provides H₂ storage in an open loop system. (iv) Reduction to practice of the H₂CAR route has the potential to provide the transportation sector for the foreseeable future, using the existing infrastructure. The rationale of using H₂ in the H₂CAR process is explained by the significantly higher annualized average solar energy conversion efficiency for hydrogen generation versus that for biomass growth. For coal to liquids, the advantage of H₂CAR is that there is no additional CO₂ release to the atmosphere due to the replacement of petroleum with coal, thus eliminating the need to sequester CO₂.