Stabilized chlorine dioxide to preserve carbohydrate feedstocks

Patent metadata

Field	Value
Publication number	US-9504710-B2
Application number	US-201514626756-A
Country	US
Kind code	B2
Filing date	Feb 19, 2015
Priority date	Sep 25, 2009
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

A process to preserve a carbohydrate feedstock against contaminant microorganisms comprises contacting the carbohydrate feedstock with a stabilized chlorine dioxide at a pH of at least 2.6. The carbohydrate feedstock preferably comprises a naturally-occurring carbohydrate, particularly a carbohydrate having a reducing end group. The process is particularly suitable to treat feedstocks used in biorefining processes, such as in ethanol fermentation.

First claim

What is claimed is:

1. A process to preserve a carbohydrate feedstock against microorganisms comprising contacting the carbohydrate feedstock in a unit operation wherein a unit operation is storage or transport with a stabilized chlorine dioxide at a pH of at least 2.6 prior to use of the carbohydrate feedstock as a fermentable sugar and in the absence of added acid to generate chlorine dioxide, wherein the concentration of the carbohydrate is at least 1%, by weight of the feedstock, and the amount of stabilized chlorine dioxide added is 10 to 10000 mg/kg as ClO 2 , based on total feedstock weight.

2. The process of claim 1 wherein the concentration of carbohydrate in the feedstock is 1.0 to 70%, based on the total feedstock weight, and the pH is at least 3.

3. The process of claim 1 wherein the carbohydrate is a naturally-occurring carbohydrate, having a reducing end group.

4. The process of claim 3 wherein the carbohydrate is a monosaccharide, disaccharide, oligosaccharide, polysaccharide, or mixtures of two or more thereof.

5. The process of claim 1 wherein the carbohydrate feedstock is a solution or suspension of a fermentable sugar.

6. The process of claim 5 wherein the carbohydrate feedstock is corn steep liquor.

7. The process of claim 1 wherein the carbohydrate feedstock is molasses.

8. The process of claim 1 wherein the carbohydrate feedstock further comprises enzymes, surfactants, dispersants, antifoaming compositions, minerals, trace elements, and combinations of two or more thereof.

9. The process of claim 1 wherein the carbohydrate feedstock is a cellulose feedstock.

10. The process of claim 1 wherein the stabilized chlorine dioxide is one or more chlorine dioxide-containing oxy-chlorine complexes.

11. The process of claim 1 wherein the stabilized chlorine dioxide is one or more chlorite-containing compounds.

12. The process of claim 10 wherein the one or more chlorine dioxide-containing oxy-chlorine complexes is a complex of chlorine dioxide with carbonate, a complex of chlorine dioxide with bicarbonate or a mixture thereof.

13. The process of claim 11 wherein the one or more chlorite-containing compounds is an aqueous solution of an alkali metal or alkaline earth metal chlorite.

14. The process of claim 13 wherein the one or more chlorite-containing compounds is an aqueous solution of an alkali metal chlorite.

15. The process of claim 14 wherein the alkali metal chlorite is sodium chlorite.

16. The process of claim 11 wherein the pH is 3 to 9.

17. The process of claim 11 wherein the pH is 3.5 to 8.

18. The process of claim 11 wherein the pH is 4 to 7.

19. The process of claim 11 wherein the pH is 4.5 to 7.

20. The process of claim 14 wherein the amount of stabilized chlorine dioxide added is 50 to 1000 mg/kg, based on total feedstock weight.

Assignees

• Du Pont
• Du Pont

Inventors

• Sumner Eric Guy
• Okull Derrick
• Solomon Ethan Baruch

Classifications

• A23B2/788

  Inorganic compounds · CPC title

• C12P7/06

  Ethanol, i.e. non-beverage · CPC title

• C01B11/024

  from chlorites · CPC title

• C01B11/02

  Oxides of chlorine · CPC title

• A61K33/20 Primary

  Elemental chlorine; Inorganic compounds releasing chlorine · CPC title