Alkaline peroxide treatment of agricultural byproducts

• US 4,806,475 A
• Filed: 09/29/1986
• Issued: 02/21/1989
• Est. Priority Date: 12/28/1983
• Status: Expired due to Term

• Current Assignee: The United States of America As Represented By The Secretary of Agriculture
• Original Assignee: United States Department Of Agriculture
• Inventors: Gould, John M.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Graeter, Janelle
• Application Number:
  US06/912,296
• Time in Patent Office: 876 Days
• Field of Search: 435/165, 127/37, 530/500, 162/78, 162/99
• US Class Current: 435/165
• CPC Class Codes: A23G 2200/06 containing beet sugar or cane sugar if specifically mentioned or containing other carbohydrates, e.g. starches, gums, alcohol sugar, polysaccharides, dextrin or containing high or low amount of carbohydrate
• CPC Class Codes: A23G 3/346 Finished or semi-finished products in the form of powders, paste or liquids A23G3/343 takes precedence
• CPC Class Codes: A23K 10/32 from hydrolysates of wood or straw
• CPC Class Codes: C08B 1/00 Preparatory treatment of cellulose for making derivatives thereof , e.g. pre-treatment, pre-soaking, activation
• CPC Class Codes: C08H 6/00 Macromolecular compounds derived from lignin, e.g. tannins, humic acids
• CPC Class Codes: C08H 8/00 Macromolecular compounds derived from lignocellulosic materials pretreatment thereof B27N
• CPC Class Codes: C12P 7/10 substrate containing cellulosic material
• CPC Class Codes: D21C 3/006 with compounds not otherwise provided for
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

Nonwoody lignocellulosic portions of plant fruits, roots, and tubers, such as sugar beet pulp, citrus pulp, seed hulls, and cereal bran are treated with hydrogen peroxide under alkaline conditions thereby delignifying the materials and rendering the cellulose and hemicellulose highly available for subsequent use. The products are characterized by enhanced water-binding capacity of the cellulose as indicated by high water swellability. The products are also nontoxic and thereby useful as carbohydrate sources in ruminant feeds, as microbial feedstocks, and as sources of dietary fiber for humans and other monogastrics.

Claims

1. A method for treating a substrate to yield a cellulosic product wherein said substrate is a nonwoody lignocellulosic portion of a fruit, root, or tuber, said method comprising treating said substrate in a reaction medium comprising an aqueous solution of strong alkali and hydrogen peroxide so as to solubilize at least a portion of the lignin and to enhance the water-binding capacity of the cellulose, thereby producing a water-soluble lignin-containing fraction and a water-insoluble cellulose-containing fraction, and recovering the water-insoluble fraction from the reaction medium as said cellulosic product.

2. A method as described in claim 1 wherein said substrate is sugar beet pulp.

3. A method as described in claim 1 wherein said substrate is citrus pulp.

4. A method as described in claim 1 wherein said substrate is seed hulls.

5. A method as described in claim 1 wherein said substrate is cereal bran.

6. A method as described in claim 1 wherein said strong alkali is sodium hydroxide, and the pH is controlled within the range of about 11.2 to about 11.8.

10. The cellulosic product produced by the method of claim 1.

11. The cellulosic product produced by the method of claim 2.

12. The cellulosic product produced by the method of claim 3.

13. The cellulosic product produced by the method of claim 4.

14. The cellulosic product produced by the method of claim 5.

15. The cellulosic product produced by the method of claim 6.

7. A method for treating a substrate to yield a cellulosic product wherein said substrate is a nonwoody lignocellulosic component of a plant, said method comprising treating said substrate in a reaction medium comprising an aqueous solution of strong alkali and hydrogen peroxide at a pH in the range of about 11.2 to about 11.8 so as to solubilize at least a portion of the lignin and to enhance the water-binding capacity of the cellulose, thereby producing a lignin-containing water-soluble fraction and a cellulose-containing water-insoluble fraction, and recovering the water-insoluble fraction from the reaction medium as said cellulosic product.

8. A method as described in claim 7 wherein said substrate is selected from the group consisting of sugar beet pulp, citrus pulp, seed hulls, and cereal bran.

9. A method as described in claim 8 wherein said strong alkali is sodium hydroxide.

16. The cellulosic product produced by the method of claim 7.

17. The cellulosic product produced by the method of claim 8.

18. The cellulosic product produced by the method of claim 9.