A method of processing an aqueous hemicellulosic stream containing lignin, comprising: (a) contacting an aqueous hemicellulosic stream containing lignin with a C.sub.3-8 alkyl alcohol at elevated temperature and acidic pH; (b) separating the reaction mixture obtained from step (a) into an aqueous phase containing hemicellulose-derived monosaccharide and an organic phase containing C.sub.3-8 alkyl alcohol; (c) concentrating the organic phase obtained from step (b) to remove at least some C.sub.3-8 alkyl alcohol; (d) treating the residue from step (c) with water or an aqueous medium having an alkaline pH; and (e) recovering C.sub.3-8 alkyl alcohol from the product of step (d).

A method of processing an aqueous hemicellulosic stream containing lignin, comprising: (a) contacting an aqueous hemicellulosic stream containing lignin with a C.sub.3-8 alkyl alcohol at elevated temperature and acidic pH; (b) separating the reaction mixture obtained from step (a) into an aqueous phase containing hemicellulose-derived monosaccharide and an organic phase containing C.sub.3-8 alkyl alcohol; (c) concentrating the organic phase obtained from step (b) to remove at least some C.sub.3-8 alkyl alcohol; (d) treating the residue from step (c) with water or an aqueous medium having an alkaline pH; and (e) recovering C.sub.3-8 alkyl alcohol from the product of step (d).

Protein-rich nutrient supplements and animal feed supplements derived from an anaerobic bacterial process are generated through a myriad of cell rupturing and protein fractionation/purification processes. Bacterial fermentation systems and methods of obtaining one or more protein-containing portions from a fermentation process using carbon monoxide-containing gaseous substrates are provided. The invention further provides compositions of protein-rich nutrient supplements with useful applications for intake by a variety of different animals and humans.

Methods and systems to control flexible gas fermentation platforms for improved conversion of CO.sub.2 into products is developed and particularly relates to a control process and system to control a ratio of feedstock gases and maximize the concentration of inert components in a bioreactor tail gas stream and or bioreactor headspace. Improved carbon utilization results though providing the most beneficial ratio of substrates to the bioreactor of the fermentation process.

Methods and systems to control flexible gas fermentation platforms for improved conversion of CO.sub.2 into products is developed and particularly relates to a control process and system to control a ratio of feedstock gases and maximize the concentration of inert components in a bioreactor tail gas stream and or bioreactor headspace. Improved carbon utilization results though providing the most beneficial ratio of substrates to the bioreactor of the fermentation process.

The disclosure provides methods to improve the economics of the gas fermentation process. A fermentation process is integrated with an industrial or syngas process and an reverse water gas shift process. An intermittent supply of reverse water gas shift process feedstock from the reverse water gas shift process is provided to the bioreactor for fermentation. The reverse water gas shift process feedstock may supplement or partially displace the C1 feedstock from the industrial or syngas process. Whether the reverse water gas shift process feedstock supplements or displaces the C1 feedstock may be based upon a function of the cost per unit of the C1 feedstock, the cost per unit of the reverse water gas shift process feedstock, and the value per unit of the fermentation product, or may depend upon the target gas ratio of the feedstock to the gas fermentation process.

The disclosure provides methods to improve the economics of the gas fermentation process. A fermentation process is integrated with an industrial or syngas process and an reverse water gas shift process. An intermittent supply of reverse water gas shift process feedstock from the reverse water gas shift process is provided to the bioreactor for fermentation. The reverse water gas shift process feedstock may supplement or partially displace the C1 feedstock from the industrial or syngas process. Whether the reverse water gas shift process feedstock supplements or displaces the C1 feedstock may be based upon a function of the cost per unit of the C1 feedstock, the cost per unit of the reverse water gas shift process feedstock, and the value per unit of the fermentation product, or may depend upon the target gas ratio of the feedstock to the gas fermentation process.

An integrated process and system for the production of at least one gas fermentation product from a gaseous stream has been developed. The disclosure provides improved carbon utilization through both the recycle of a bioreactor tail gas via various different flow schemes and the employment of a CO.sub.2 to CO conversion system such as a reverse water gas shift unit. Recycling of the bioreactor tail gas and employment of a CO.sub.2 to CO conversion process provides for favourable H.sub.2:CO molar ratios of the feed to the gas fermentation bioreactor(s) for enhanced production of fermentation products. Bypass embodiments provide for optimal sizing of the reverse water gas shift unit to minimize cost.

An integrated process and system for the production of at least one gas fermentation product from a gaseous stream has been developed. The disclosure provides improved carbon utilization through both the recycle of a bioreactor tail gas via various different flow schemes and the employment of a CO.sub.2 to CO conversion system such as a reverse water gas shift unit. Recycling of the bioreactor tail gas and employment of a CO.sub.2 to CO conversion process provides for favourable H.sub.2:CO molar ratios of the feed to the gas fermentation bioreactor(s) for enhanced production of fermentation products. Bypass embodiments provide for optimal sizing of the reverse water gas shift unit to minimize cost.

An improved dry grind system and method for producing a sugar stream from grains or similar carbohydrate sources and/or residues, such as for biochemical production. In particular, after saccharification and prior to a sugar conversion process, a sugar/carbohydrate stream is removed from a saccharified stream. The sugar/carbohydrate stream includes a desired Dextrose Equivalent (DE) where DE describes the degree of conversion of starch to dextrose can be produced, with the such sugar stream being available for biochemical production, e.g., alcohol production, or other processes. In addition, the systems and methods also can involve the removal of certain grain components, e.g., corn kernel components, including protein and/or fiber. Sugar stream production occurs on the front end of the system and method.