ABSTRACT
A number of fermentations exhibit product inhibition. Fermentations of alcohols such as ethanol and butanol are typical, showing serious product inhibition. This chapter explains the characteristics of perstraction, focusing on the experimental results. The validity of biomass alcohols is dependent on the development of a low-cost and energy-efficient recovery process. Solvent extraction is one of the most promising methods, because it has been established as a unit operation and employed on a large scale in many chemical industries. It has several problems that should be solved before it is applied to fermentation. One of them is solvent toxicity to microorganisms. Another problem is how to reduce the solvent amount required in the separation of alcohols from a fermentation broth. This problem had been overcome by using a liquid membrane supported with a porous hydrophobic membrane under vacuum. The oleyl alcohol liquid membrane showed excellent separation performance.
