Continuous process for producing n-butanol employing anaerobic

Abstract

There is disclosed, in one aspect, a continuous process for producing n-butanol. This process comprises continuously (a) contacting at least one carbohydrate-containing substrate, such as blackstrap molasses, with an n-butanol producing culture, such as Clostridium acetobutylicum (Weizmann), in water to effect the fermentation of the substrate and form a product mixture comprising n-butanol, (b) extracting the product mixture from the substrate, culture, and water by forming a solution of the product mixture with an extraction solvent, such as a one or two carbon fluorocarbon, (c) separating the extraction solvent from the product mixture by vaporizing substantially all of the solvent without substantial vaporization of the product mixture, and (d) condensing the vaporized solvent for reuse as an extraction solvent in step (b). In another aspect, there is disclosed an apparatus for conducting such a process. This apparatus comprises (a) means for holding the substrate and water, (b) reactor means for holding the culture and facilitating its contact with the substrate, (c) means for feeding the substrate from the holding means to the reactor means for reaction with the culture to produce the reaction product mixture, (d) extraction means for contacting the reaction product mixture with an extraction solvent to form a solution of the solvent with the product mixture, (e) means for vaporizing the extraction solvent while substantially avoiding the vaporization of the product mixture, and (f) means for condensing the vaporized extraction solvent for reuse.