Gasification and synthesis gas fermentation: an alternative route to biofuel production

Abstract

Lignocellulosic biomass has been identified among the renewable energy sources to have the highest potential to minimize dependency on dwindling supplies of fossil fuels. Conversion of this biomass to biofuels by microorganisms through direct hydrolysis and fermentation can be challenging. Alternatively, biomass can be converted to synthesis gas (a mixture of CO, CO₂, N₂ and H₂) through gasification and transformed to fuels using microbial catalysts that can convert the CO, H₂ and CO₂ to fuels such as ethanol, butanol and hydrogen. Biomass gasification–fermentation processing systems have shown promise and companies are now entering the marketplace for commercial-scale ethanol production from synthesis gas. Isolation of new organisms capable of higher product yield, as well as functional implementation of bioreactors that enhance gas solubility for microbial fermentation, make this technology an attractive option for reducing our dependency on fossil fuels.

Acknowledgements

We wish to thank Dr Sherry Tove for her useful comments regarding the manuscript preparation.

Financial & competing interests disclosure

Support for some of the studies discussed in this review was provided to Rachel M Slivka, Mari S Chinn and Amy M Grunden by the North Carolina Biotechnology Center grant number 2008-MRG-1104. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views and policies of the North Carolina Biotechnology Center. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.