Biofuel Production by Continuous Acetone-Butanol-Ethanol (ABE) Ferementation Coupled with Membrane Separation

Butanol is a liquid fuel superior to ethanol that can be produced from renewable biomass by the acetone-butanol-ethanol (ABE) fermentation process. However, the ABE fermentation process economics is hampered by low conversion rate due to severe product inhibition and by energy intensive product recovery (traditionally by distillation). The overall objective of this combined Phase I and Phase II projects is to develop a more effficient biobutanol production process in which fermentation is combined with a membrane separation process that continuously extracts ABE from the fermentor. In Phase I of this project, a nanoporous membrane capable of selective removal of butanol from the fermentation solution was developed and production of concentrated butanol was demonstrated in bench-scale tests. Initial economic analysis showed that membrane separation process can significantly reduce butanol production costs and process energy consumption as compared to traditional distillation. In Phase II of this project the membrane performance will be optimized, a pilot scale membrane module developed and tested. If successful the proposed technology will enable utilization of abundant biomass for production of renewable biofuel and biochemical - butanol. Butanol when consumed in an internal combustion engine yields no SOX, NOX or carbon monoxide which are all environmentally harmful byproducts of combustion. The wide utilization of butanol as the biofuel will significantly reduce the environmental pollution and decrease the dependence of the US economy on the foreign oil.