Process for producing fuel using three fermentations
AssigneeIogen Corporation
InventorsPatrick J. Foody, Brian Foody
Life of this patent
Estimating the term…
Abstract
A process for forming a fuel or a fuel intermediate using three fermentations includes treating a feedstock to obtain a fermentable carbohydrate, conducting a first fermentation to ferment the fermentable carbohydrate to fermentation product, obtaining biogas produced from a second fermentation that includes anaerobic digestion, and conducting a third fermentation to ferment a gas to produce fermentation product, where the gas contains one or more components obtained or derived from the biogas. An aqueous stream containing fermentation product produced in the third fermentation is used within the process.
Claims23
A process for converting feedstock to a fermentation product, said process comprising:
- treating the feedstock to obtain a fermentable carbohydrate;
- conducting a first fermentation to produce fermentation product, said first fermentation conducted on the fermentable carbohydrate;
- obtaining biogas produced from a second fermentation, said second fermentation comprising an anaerobic digestion;
- conducting a third fermentation to produce fermentation product, said third fermentation conducted on a gas substrate comprising one or more components obtained or derived from the biogas, said one or more components selected from carbon monoxide, carbon dioxide, and hydrogen;
- using an aqueous stream comprising fermentation product produced in the third fermentation within the process such that fermentation product produced in the third fermentation is copresent with fermentable carbohydrate in a carbohydrate fermentation;
- and
- recovering the fermentation product produced in the first and third fermentations.
A process for converting cellulosic feedstock to ethanol, said process comprising:
- (i) treating the cellulosic feedstock to produce a sugar;
- (ii) conducting a first fermentation to produce ethanol, said first fermentation conducted using the sugar as a substrate;
- (iii) feeding a portion of the treated feedstock not converted to ethanol to an anaerobic digester to produce biogas;
- (iv) collecting biogas from the anaerobic digester, said biogas comprising carbon dioxide and methane;
- (v) fermenting a gas to produce ethanol, said gas comprising one or more components of the collected biogas, one or more components derived from the collected biogas, or a combination thereof;
- and
- (vi) recovering the ethanol produced in (ii) and (v),
- wherein the gas fermented in (v) comprises hydrogen produced by:
- (a) converting fossil methane to carbon monoxide and hydrogen by reforming;
- (b) converting at least a portion of the carbon monoxide by a water-gas shift reaction to carbon dioxide, thereby producing a stream comprising fossil carbon dioxide and hydrogen;
- and
- (c) separating at least a portion of the hydrogen from the stream of step (b) from non-hydrogen components to produce a stream enriched in hydrogen and a stream comprising fossil carbon dioxide, and
- wherein the process comprises using an aqueous stream comprising ethanol produced in (v) within the process such that ethanol produced in a gas fermentation is copresent with sugar being fermented.
A process for converting cellulosic feedstock to ethanol, said process comprising:
- (i) treating the cellulosic feedstock to produce a sugar;
- (ii) conducting a first fermentation to produce ethanol, said first fermentation conducted using the sugar as a substrate;
- (iii) feeding a portion of the treated feedstock not converted to ethanol to an anaerobic digester to produce biogas;
- (iv) collecting biogas from the anaerobic digester, said biogas comprising carbon dioxide and methane;
- (v) fermenting a gas to produce ethanol, said gas comprising one or more components of the collected biogas, one or more components derived from the collected biogas, or a combination thereof;
- and
- (vi) recovering the ethanol produced in (ii) and (v), and
- wherein the process comprises using an aqueous stream comprising ethanol produced in (v) within the process such that ethanol produced in a gas fermentation is copresent with sugar being fermented.
Dependencies are inferred from the claim text.