Production of alcohol esters and in situ product removal during alcohol fermentation

A method for producing butanol and butyl esters from a feedstock comprising:

• (a) providing a feedstock;
• (b) liquefying the feedstock to create a liquefied biomass comprising oligosaccharides;
• (c) separating the feedstock slurry to produce an aqueous stream comprising oligosaccharides, an oil stream, and solids;
• (d) adding the aqueous stream to a fermentation vessel containing a fermentation broth;
• (e) saccharifying the oligosaccharides of the aqueous stream;
• (f) fermenting the products of the oligosaccharide saccharification present in the aqueous stream to produce butanol and concurrently contacting the butanol with at least one carboxylic acid and at least one catalyst capable of esterifying the carboxylic acid with the butanol to form butyl esters of the carboxylic acid, wherein the catalyst is an enzyme selected from an esterase, lipase, phospholipase, lysophospholipase, or a mixture thereof,
• wherein the carboxylic acid is present at a concentration sufficient to produce a two-phase mixture;
• and optionally steps (e) and (f) occur concurrently.

A method for producing butanol and butyl esters from a feedstock comprising:

• (a) providing a feedstock;
• (b) liquefying the feedstock to create a liquefied biomass comprising oligosaccharides;
• (c) separating the feedstock slurry to produce a stream comprising oligosaccharides and oil, and solids;
• (d) adding the stream to a fermentation vessel containing a fermentation broth;
• (e) saccharifying the oligosaccharides of the stream;
• (f) fermenting the products of the oligosaccharide saccharification present in the stream to produce butanol and concurrently contacting the butanol with at least one carboxylic acid and at least one catalyst capable of esterifying the carboxylic acid with the butanol to form butyl esters of the carboxylic acid, wherein the catalyst is an enzyme selected from an esterase, lipase, phospholipase, lysophospholipase, or a mixture thereof,
• wherein the carboxylic acid is present at a concentration sufficient to produce a two-phase mixture;
• and optionally steps (e) and (f) occur concurrently.