Methods and Systems for Removing Undissolved Solids Prior to Extractive Fermentation in the Production of Butanol

Abstract

A method and system for efficiently producing a fermentative product alcohol such as butanol utilizing in situ product extraction are provided. The efficiency is obtained through separating undissolved solids after liquefying a given feedstock to create a feedstock and prior to fermentation, for example, through centrifugation. Removal of the undissolved solids avoids problems associated with having the undissolved solids present during in situ production extraction, and thereby increases the efficiency of the alcohol production.

1 - 30 . (canceled) 
     
     
         31 . A method for producing butanol comprising:
 providing a feedstock;   liquefying the feedstock to create a feedstock slurry, wherein the feedstock slurry comprises fermentable carbon source, oil, and undissolved solids;   separating the feedstock slurry to create (i) an aqueous solution comprising fermentable carbon source, (ii) a wet cake comprising undissolved solids, and (iii) an oil phase;   contacting the aqueous solution with a fermentation broth comprising a microorganism whereby butanol is produced;   removing the butanol from the fermentation broth as the butanol is produced.   
     
     
         32 . The method of  claim 31 , wherein the feedstock is corn and the oil is corn oil. 
     
     
         33 - 35 . (canceled) 
     
     
         36 . The method of  claim 31 , wherein the feedstock slurry is separated by decanter bowl centrifugation, three-phase centrifugation, disk stack centrifugation, filtering centrifugation, decanter centrifugation, filtration, vacuum filtration, beltfilter, pressure filtration, filtration using a screen, screen separation, grating, porous grating, flotation, hydroclone, filter press, screwpress, gravity settler, vortex separator, or combination thereof. 
     
     
         37 - 38 . (canceled) 
     
     
         39 . The method of  claim 31 , wherein the wet cake is washed with water to recover sugars in the wet cake. 
     
     
         40 . The method of  claim 31 , wherein the removal comprises liquid-liquid extraction. 
     
     
         41 . The method of  claim 40 , wherein an extractant for the liquid-liquid extraction is an organic extractant. 
     
     
         42 - 46 . (canceled) 
     
     
         47 . The method of  claim 31 , wherein the microorganism is a recombinant microorganism comprising a butanol biosynthetic pathway. 
     
     
         48 . The method of  claim 31 , wherein the butanol is isobutanol. 
     
     
         49 - 58 . (canceled) 
     
     
         59 . The method of  claim 31 , wherein the wet cake is processed to produce Dried Distillers' Grains with Solubles (DDGS). 
     
     
         60 . The method of  claim 59 , wherein the DDGS is used as a feed supplement. 
     
     
         61 . The method of  claim 59 , wherein the DDGS is used as an animal feed product. 
     
     
         62 . The method of  claim 61 , wherein the animal feed product comprises 20-35 wt % crude protein, 1-20 wt % crude fat, 0-5 wt % triglycerides, and 4-10 wt % fatty acids. 
     
     
         63 . The method of  claim 62 , wherein the animal feed product further comprises 1-2 wt % lysine, 11-23 wt % neutral detergent fiber (NDF), and 5-11 wt % acid detergent fiber (ADF). 
     
     
         64 . The method of  claim 39 , wherein the recovered sugars and water are recycled to the liquefaction step. 
     
     
         65 . The method of  claim 41 , wherein the extractant is selected from C 4  to C 22  fatty alcohols, C 4  to C 28  fatty acids, esters of C 4  to C 28  fatty acids, C 4  to C 22  fatty aldehydes, and mixtures thereof. 
     
     
         66 . The method of  claim 41 , wherein the extractant is selected from oleyl alcohol, behenyl alcohol, cetyl alcohol, lauryl alcohol, myristyl alcohol, stearyl alcohol, 1-undecanol, oleic acid, lauric acid, myristic acid, stearic acid, methyl myristate, methyl oleate, undecanal, lauric aldehyde, 20-methylundecanal, and mixtures thereof. 
     
     
         67 . The method of  claim 41 , wherein the extractant is derived from the oil phase.