Upgrading process streams

Abstract

Biomass (e.g., plant biomass, animal biomass, and municipal waste biomass) is processed to produce useful intermediates and products, such as energy, fuels, foods or materials. Systems, methods and equipment are described for upgrading process streams using electrodialysis or electrodialysis reversal.

What is claimed is: 
     
         1 . A method comprising:
 saccharifying a biomass to obtain a sugar solution comprising one or more sugars; and   fermenting the sugar solution to produce a fermentation broth comprising an unconverted sugar and a fermentation product;   wherein the method further comprises removing salts, ions, partially ionized acids or fully ionized acids from the sugar solution or the fermentation broth utilizing an electrodialysis system.   
     
     
         2 . The method of  claim 1 , wherein the one or more sugars comprise glucose, xylose, arabinose, fructose, mannose, or galactose. 
     
     
         3 . The method of  claim 1 , wherein the concentration of the sugar solution is greater than 40%. 
     
     
         4 . The method of  claim 1 , wherein the electrodialysis system utilizes common or standard electrodialysis, electrodialysis reversal, or bipolar membrane electrodialysis. 
     
     
         5 . The method of  claim 1 , wherein the biomass comprises a cellulosic or lignocellulosic material. 
     
     
         6 . The method of  claim 5 , wherein the cellulosic or lignocellulosic material has been treated with a physical treatment comprising mechanical treatment, chemical treatment, irradiation, sonication, oxidation, pyrolysis or steam explosion. 
     
     
         7 . The method of  claim 1 , wherein the biomass is saccharified utilizing one or more enzymes, or one or more acids. 
     
     
         8 . The method of  claim 1 , further comprising concentrating the sugar solution or fermentation broth prior to electrodialysis. 
     
     
         9 . The method of  claim 1 , further comprising purifying the sugar solution or fermentation broth by a method selected from the group consisting of chromatography, filtration, centrifugation, precipitation, distillation, complexation, and combinations thereof. 
     
     
         10 . The method of  claim 9 , wherein the purifying removes impurities comprising cells, cellular debris, proteinaceous material, acids, bases, salts, partial hydrolysis products, lignin, lignin residues, inorganic solids, remnants of saccharified or fermented biomass, and combinations thereof. 
     
     
         11 . The method of  claim 1 , further comprising decolorizing the sugar solution or fermentation broth prior to electrodialysis. 
     
     
         12 . The method of  claim 11 , wherein the color of the sugar solution or fermentation broth is less than about 100 color units after decolorizing. 
     
     
         13 . The method of  claim 1 , further comprising adding a base to the fermentation broth prior to electrodialysis. 
     
     
         14 . The method of  claim 1 , wherein an ionic strength of the sugar solution or fermentation broth prior to electrodialysis is between about 500 and about 50,000 μS/cm, and wherein the ionic strength of the sugar solution or fermentation broth after electrodialysis is between 1 and 100 μS/cm. 
     
     
         15 . The method of  claim 1 , wherein the salts, ions, partially ionized acids, or fully ionized acids comprise lithium, sodium, potassium, magnesium, calcium, strontium, barium, scandium, titanium, chromium, manganese, iron, nickel, copper, zinc, aluminum, lanthanum, cerium, uranium, fluoride, chloride, bromide, iodide, sulfate, sulfide, phosphate, nitrate, carbonate, borate, chlorate, arsenate, or aluminate. 
     
     
         16 . The method of  claim 1 , wherein utilizing the electrodialysis system comprises applying a voltage of between about 10 and 150V across ion selective membranes while flowing the sugar solution or fermentation broth past the membranes. 
     
     
         17 . The method of  claim 1 , wherein the fermentation product comprises a product selected from the group consisting of: hydrogen, an alcohol, a carboxylic acid or a salt or ester thereof, a hydrocarbon, and mixtures of any of these. 
     
     
         18 . The method of  claim 17 , wherein the fermentation product comprises an alcohol selected from the group consisting of: ethanol, propanol, butanol, propylene glycol, 1,3-propanediol, 1,4-butanediol, erythritol, glycerol, sorbitol, threitol, arabitol, ribitol, mannitol, dulcitol, fucitol, iditol, isomalt, maltitol, lactitol, and xylitol. 
     
     
         19 . The method of  claim 17 , wherein the fermentation product comprises a carboxylic acid selected from the group consisting of: lactic acid, pyruvic acid, polylactic acid, citric acid, formic acid, acetic acid, propionic acid, tartaric acid, butyric acid, succinic acid, valeric acid, caproic acid, 3-hydroxypropionic acid, palmitic acid, stearic acid, oxalic acid, malonic acid, glutaric acid, oleic acid, linoleic acid, glycolic acid, gamma-hydroxybutyric acid, and mixtures thereof, salts thereof, and mixtures of the acids and their respective salts. 
     
     
         20 . The method of  claim 1 , further comprising converting an organic acid salt to its neutralized form and isolating the neutralized organic acid.