Abstract: Starch derived from a dry milled cereal grain such as corn or milo is hydrolyzed to provide a sterile aqueous fermentable sugar solution which is especially adapted for fermentative conversion to ethanol with minimum thermal expenditure. Following an initial mild hydrolysis to thin, or liquefy, the starch, substantially all of the water insoluble protein and oil components, and a portion of the water soluble components, e.g., sugars, lipids, proteins and vitamins, are separately recovered from the partial starch hydrolysate with the water solubles being recycled to the system. Thereafter, the partial starch hydrolysate is subjected to further hydrolysis to provide an aqueous solution of fermentable sugar.

Abstract: The yield of fermentable sugar, largely glucose (dextrose), resulting from the acid catalyzed hydrolysis of a carbohydrate polymer such as starch or cellulose can be significantly increased by the addition to the hydrolysate under acid hydrolysis conditions of water soluble non-fermentable carbohydrate such as stillage recovered from a downstream ethanol distillation facility.

Abstract: Starch derived from a dry milled cereal grain such as corn or milo is hydrolyzed to provide a sterile aqueous fermentable sugar solution which is especially adapted for fermentative conversion to ethanol with minimum thermal expenditure. Following a preliminary acid-catalyzed hydrolysis of the starch to provide a sterile hydrolysate slurry, the slurry is further hydrolyzed in the presence of added aqueous non-fermentable carbohydrate to reequilibrate the hydrolysis reaction in favor of increased production of fermentable sugar, primarily glucose. Substantially all of the water insoluble protein and oil components, and a portion of the water soluble components, e.g., sugars, proteins and vitamins, are separately recovered from the sterile hydrolysate either before or after the further hydrolysis step with the water solubles being recycled to the system to effect reequilibration of a further quantity of hydrolysate.

Abstract: An improved process is provided for the continuous fermentation of sugar to ethanol in a series of fermentation vessels featuring yeast recycle which is independent of the conditions of fermentation occurring in each vessel at a particular point in time. The process facilitates the management of yeast levels in each fermentation vessel so as to provide an optimum overall rate of ethanol production.

Abstract: A feed containing a sterilie aqueous solution of fermentable sugar and minor amounts of sugar oligomers and/or sugar repolymerizates is continuously converted by fermentation to dilute aqueous ethanol ("beer") in a series of agitated fermentation vessels employing at least two strains of yeast, the first of which provides relatively high rates of conversion of the fermentable sugar to ethanol and the second of which provides relatively high rates of conversion of the sugar oligomers and/or sugar repolymerizates to ethanol.

Abstract: Substantially anhydrous, i.e., absolute, ethanol is distilled at high thermal efficiency from a dilute feedstock such as a fermentate ("beer") containing one or more low boiling components whose removal at least in part prior to anhydrous distillation is necessary in order to achieve an acceptable degree of phase separation in a decanter. Most of the low boiling component(s) are removed from the feed in a rectifying column with the balance of the low boiling component(s), insufficient in amount to seriously interfere with proper operation of the decanter, being removed from the system employing a light-ends column. Both the anhydrous column and the light-ends column are operated at substantially superatmospheric pressure with thermal values recovered from these columns being used in the operation of the rectifying column.

Abstract: An aqueous starch slurry is hydrolyzed in sequential liquefication and saccharification steps to provide saccharified starch containing from about 60 to about 80 weight percent of fermentable sugar based on the weight of the original starch present. Further saccharification is carried out either in one or more fermentation vessels wherein conversion of the sugar to ethanol simultaneously takes place or in one or more additional saccharification vessels.

Abstract: Water soluble oxygenated hydrocarbons produced by microbial fermentation, e.g., ethanol, butanol, acetone, etc., are conveniently and economically recovered with a minimum expenditure of energy by passing heated by-product carbon dioxide gas through at least a portion of the fermentation medium to simultaneously vaporize and carry off oxygenated hydrocarbon fermentation product dissolved therein and reduce the temperature of the fermentation medium to a level conducive to maximum oxygenated hydrocarbon production. The vaporized oxygenated hydrocarbon fermentation product is separated from the carbon dioxide gas in a scrubbing unit and the resulting aqueous solution of product is concentrated, if desired, by distillation.

Abstract: Starch derived from a dry milled cereal grain such as corn or milo is hydrolyzed to provide a sterile aqueous fermentable sugar solution which is especially adapted for fermentative conversion to ethanol with minimum thermal expenditure. Following an initial acid-catalyzed hydrolysis to thin, or liquefy, the starch, substantially all of the water insoluble protein and oil components, and a portion of the water soluble components, e.g., sugars, proteins and vitamins, are separately recovered from the partial starch hydrolysate with the water solubles being recycled to the system. Thereafter, the partial starch hydrolysate is subjected to further hydrolysis in the presence of an acidic cationic exchange resin as catalyst to provide an aqueous solution of fermentable sugar.

Abstract: A fermentable sugar feed containing fermentable sugar oligomers is continuously converted by fermentation to dilute aqueous ethanol ("beer") in a series of agitated fermentation vessels employing at least two strains of yeast, one of which provides a relatively high rate of conversion of fermentable sugar to ethanol and the other of which provides a relatively high rate of conversion of fermentable sugar oligomer to ethanol.

Abstract: An improved process is provided for the continuous fermentation of sugar to ethanol in a series of fermentation vessels featuring yeast recycle which is independent of the conditions of fermentation occurring in each vessel at a particular point in time. The process facilitates the management of yeast levels in each fermentation vessel so as to provide an optimum overall rate of ethanol production.

Abstract: A carbohydrate polymer such as starch and/or cellulose is converted to ethanol by a process in which an aqueous slurry of the carbohydrate polymer acid hydrolyzed to provide a sterile fermentable sugar solution is thereafter continuously converted by fermentation to dilute aqueous ethanol ("beer") in a series of agitated fermentations vessels which contain progressively more ethanol and less fermentable suger employing at least two strains of yeast for the fermentation, one of which provides a high rate of ethanol production in a fermentation medium containing a relatively low concentration of ethanol and a relatively high concentration of fermentable sugar and the other of which provides a high rate of ethanol production in a fermentation medium containing a relatively high concentration of ethanol and a relatively low concentration of fermentable sugar.

Abstract: Starch derived from dry milled corn is hydrolyzed to provide a sterile aqueous fermentable sugar solution which is especially adapted for fermentative conversion to ethanol with minimum thermal expenditure. Following an initial mild hydrolysis to thin, or liquefy, the starch, substantially all of the water insoluble protein and oil components, and a portion of the water soluble components, e.g., sugars, lipids, proteins and vitamins, are separately recovered from the partial starch hydrolysate with the water solubles being recycled to the system. Thereafter, the partial starch hydrolysate is subjected to further hydrolysis to provide an aqueous solution of fermentable sugar.

Abstract: An aqueous starch slurry is initially hydrolyzed in the presence of acid or enzyme and thereafter, the liquefied starch is saccharified in the presence of an acid cationic exchange resin to provide a sterile aqueous solution containing at least about 60 weight percent fermentable sugar based on the weight of the original starch present.

Abstract: Substantially anhydrous (absolute) ethanol is economically distilled at high thermal efficiency from any dilute feedstock such as, for example, a fermentate ("beer") or the ethanol obtained from the hydration of ethylene in apparatus including a rectifying column for concentrating the ethanol, an anhydrous column for azeotropically distilling the ethanol and a decanter for separating the azeotrope-forming agent from the aqueous ethanol. Thermal values which would otherwise be lost in overhead vapors and/or stillage effluent are utilized for preheating the ethanol feed thereby leading to a significant improvement in overall thermal efficiency. Low boiling impurities, e.g., ethyl acetate, which may be present in the feed and which could interfere with proper operation of the decanter are removed from the feed to the extent necessary in a heads stripping column operated with heat supplied from the rectifying column.

Abstract: In the wet milling of a cereal grain such as corn for the recovery of starch and other products therefrom, steepwater containing much of the water soluble components of the grain, e.g., carbohydrates, proteins and minerals, is utilized as process water for each of the individual milling, screening, concentrating and washing operations and the process water is thereafter recycled for use as steepwater in a subsequent starch recovery sequence.

Abstract: Starch is recovered from an amylaceous material such as manioc root or corn in the form of an aqueous slurry containing substantially all of the soluble components, e.g., carbohydrates and proteins, of the amylaceous material prior to processing. To accomplish such recovery, amylaceous material is milled in one or more steps in the presence of water to provide a slurry containing liberated starch particles and non-starch components. The initial aqueous starch slurry is then concentrated by removal of water therefrom. The water removed from the initial starch slurry contains soluble elements of the starch and is recycled to restore these elements to the starch recovery system.

Abstract: Starch is recovered from an amylaceous root such as manioc root in the form of an aqueous slurry containing substantially all of the soluble components, e.g., sugars and proteins, of the root prior to processing. To accomplish such recovery, fragmented root is milled in one or more steps in the presence of water to provide a slurry containing liberated starch particles and fiber particles. The fiber particles are separated from the starch particles and the resulting substantially fiber-free initial aqueous starch slurry is concentrated by removal of water therefrom. The water removed from the initial starch slurry contains soluble elements of the starch and is recycled to restore these elements to the recovery system.

Abstract: Starch is converted to ethanol by a process in which an aqueous starch slurry is hydrolyzed in sequential liquefication and saccharification steps to provide sterile saccharified starch solution containing from about 60 to about 80 weight percent of fermentable sugar based on the weight of the original starch present and the fermentable sugar is thereafter continuously converted by fermentation to dilute aqueous ethanol ("beer") in a series of agitated fermentation vessels which contain progressively more ethanol and less fermentable sugar employing at least two strains of yeast for the fermentation, one of which provides a high rate of ethanol production in a fermentation medium containing a relatively low concentration of ethanol and a relatively high concentration of fermentable sugar and the other of which provides a high rate of ethanol production in a fermentation medium containing a relatively high concentration of ethanol and a relatively low concentration of fermentable sugar.

Abstract: A carbohydrate polymer such as starch and/or cellulose is converted to ethanol by a process in which an aqueous slurry of the carbohydrate polymer acid hydrolyzed to provide a sterile fermentable sugar solution is thereafter continuously converted by fermentation to dilute aqueous ethanol ("beer") in a series of agitated fermentations vessels which contain progressively more ethanol and less fermentable sugar employing at least two strains of yeast for the fermentation, one of which provides a high rate of ethanol production in a fermentation medium containing a relatively low concentration of ethanol and a relatively high concentration of fermentable sugar and the other of which provides a high rate of ethanol production in a fermentation medium containing a relatively high concentration of ethanol and a relatively low concentration of fermentable sugar.