Extraction solvents derived from oil for alcohol removal in extractive fermentation
View Patent ↗In an alcohol fermentation process, oil derived from biomass is hydrolyzed into an extractant available for in situ removal of a product alcohol such as butanol from a fermentation broth. The glycerides in the oil can be catalytically (e.g., enzymatically) hydrolyzed into free fatty acids, which form a fermentation product extractant having a partition coefficient for a product alcohol greater than a partition coefficient of the oil of the biomass for the product alcohol. Oil derived from a feedstock of an alcohol fermentation process can be hydrolyzed by contacting the feedstock including the oil with one or more enzymes whereby at least a portion of the oil is hydrolyzed into free fatty acids forming a fermentation product extractant, or the oil can be separated from the feedstock prior to the feedstock being fed to a fermentation vessel, and the separated oil can be contacted with the enzymes to form the fermentation product extractant. The fermentation product extractant can be contacted with a fermentation broth for in situ removal of a product alcohol.
1. A method for producing an alcohol comprising:
(a) providing biomass comprising water, fermentable sugars, and oil;
(b) liquefying the biomass to produce a liquefied biomass;
(c) contacting the liquefied biomass with one or more catalysts whereby at least a portion of the oil is hydrolyzed to form an extractant, wherein a partition coefficient of the extractant for the product alcohol is greater than a partition coefficient of the oil of the biomass for the product alcohol;
(d) contacting the liquefied biomass with a saccharification enzyme capable of converting oligosaccharides into fermentable sugar; contacting the liquefied biomass with a fermentation broth in a fermentation vessel;
(e) fermenting the carbon source of the liquefied biomass to produce a product alcohol;
(f) removing in situ the product alcohol from the fermentation broth by contacting the broth with the extractant;
and optionally steps (c) and (d) occur concurrently.
2. The method of claim 1 , wherein the biomass comprises corn grain, wheat, rye, barley, soy, and mixtures thereof.
3. The method of claim 1 , wherein the extractant comprises fatty acids, fatty amides, fatty alcohols, fatty esters, or mixtures thereof.
4. The method of claim 1 , wherein the one or more catalysts is selected from esterase, lipase, phospholipase, and lysophospholipase.
5. The method of claim 1 , further comprising:
inactivating the catalyst after at least a portion of the oil is hydrolyzed to form the extractant.
6. The method of claim 1 , wherein the product alcohol is butanol.
7. The method of claim 1 , wherein the biomass comprises hay, sorghum, switchgrass, and mixtures thereof.
8. The method of claim 1 , wherein the biomass comprises cellulosic material, lignocellulosic material, and mixtures thereof.
9. The method of claim 1 , wherein the biomass comprises sugar cane bagasse.
10. The method of claim 1 , wherein the biomass comprises wheat straw, barley straw, rice straw, and mixtures thereof.
11. The method of claim 1 , wherein the biomass comprises corn cobs, corn husks, corn stover, and mixtures thereof.
12. The method of claim 1 , wherein the biomass comprises crop residues.