Process for producing ethanol

• US 7,351,559 B2
• Filed: 06/29/2005
• Issued: 04/01/2008
• Est. Priority Date: 03/11/1999
• Status: Expired due to Fees

• Current Assignee: ZeaChem, Inc.
• Original Assignee: ZeaChem, Inc.
• Inventors: Verser, Dan, Eggeman, Timothy J.
• Primary Examiner(s): Lilling; Herbert J.
• Application Number:
  US11/172,376
• Publication Number:
  US 20060019360A1
• Time in Patent Office: 1,007 Days
• Field of Search: 435/135, 435/161, 435/162, 435/163
• US Class Current: 435/135
• CPC Class Codes: C07C 29/149 with hydrogen or hydrogen-containing gases
• CPC Class Codes: C07C 31/08 Ethanol
• CPC Class Codes: C07C 67/08 by reacting carboxylic acids or symmetrical anhydrides with the hydroxy or O-metal group of organic compounds
• CPC Class Codes: C07C 69/14 of monohydroxylic compounds
• CPC Class Codes: C12P 7/06 Ethanol, i.e. non-beverage
• CPC Class Codes: C12P 7/14 Multiple stages of fermentation; Multiple types of microorganisms or re-use of microorganisms
• CPC Class Codes: C12P 7/54 Acetic acid vinegar C12J
• CPC Class Codes: C12P 7/56 Lactic acid
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel
• CPC Class Codes: Y02P 20/10 Process efficiency

Abstract

A process for producing ethanol including a combination of biochemical and synthetic conversions results in high yield ethanol production with concurrent production of high value coproducts. An acetic acid intermediate is produced from carbohydrates, such as corn, using enzymatic milling and fermentation steps, followed by conversion of the acetic acid into ethanol using esterification and hydrogenation reactions. Coproducts can include corn oil, and high protein animal feed containing the biomass produced in the fermentation.

Claims

1. A method for converting a carbohydrate source and a natural gas source to an easily transportable liquid product comprising the steps of:

(a) converting said carbohydrate source to acetic acid, acetate, or mixtures thereof by fermentation;

(b) converting said acetic acid, acetate, or mixtures thereof to ethyl acetate;

(c) converting at least part of said ethyl acetate to ethanol using hydrogen obtained from said natural gas source; and

(d) transporting said ethanol or ethyl acetate to a location different than the location where it is produced.

2. The method of claim 1, wherein said carbohydrate source and said natural gas source are located within an economically feasible distance of each other and wherein said remote location to which said ethanol or ethyl acetate is transported is located at a distance at which it is uneconomical to transport the natural gas and carbohydrate.

3. The method of claim 2, wherein said economically feasible distance is less than about 500 miles and wherein said uneconomical distance is greater than about 1,000 miles.

4. The method of claim 2, wherein said carbohydrate source and said natural gas source are located on one or more Caribbean Islands and said remote location is located on the Gulf Coast.

5. The method of claim 2, wherein said carbohydrate source and said natural gas source are located in Australia, New Zealand or both and said remote location is Japan, Taiwan, Korea or China.

6. The method of claim 1, wherein said fermentation comprises the production of lactic acid, lactate or mixtures thereof in a first fermentation and the production of acetate, acetic acid or mixtures thereof in a second fermentation.

7. The method of claim 1, wherein hydrogen is obtained from said natural gas by steam reforming.