Conversion of cellulosic materials into glucose for use in bioethanol production

• US 8,895,275 B2
• Filed: 01/29/2010
• Issued: 11/25/2014
• Est. Priority Date: 03/12/2009
• Status: Expired due to Fees

• Current Assignee: University of Malaya (Government of Malaysia)
• Original Assignee: University of Malaya (Government of Malaysia)
• Inventors: Arifin, Zainudin Bin, Teoh, Teow Chong
• Primary Examiner(s): Steadman, David J
• Assistant Examiner(s): HOLLAND, PAUL J
• Application Number:
  US13/146,207
• Publication Number:
  US 20110281317A1
• Time in Patent Office: 1,761 Days
• Field of Search: None
• US Class Current: 435/165
• CPC Class Codes: C12P 7/08 produced as by-product or from waste or cellulosic material substrate
• CPC Class Codes: C13K 1/02 obtained by saccharification of cellulosic materials manufacture of fodder A23K10/32
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

A method for producing an aqueous sugar solution from cellulosic materials comprising the steps of heating ground cellulosic materials with perchloric acid; neutralizing the heated materials with an alkali to yield a salt precipitate; and filtering the salt precipitate off to obtain the aqueous sugar solution.

Claims

1. A method for producing an aqueous sugar solution from cellulosic materials, comprising:

mixing ground cellulosic materials with a superacid to form a mixture, wherein the superacid is free of periodic acid, wherein the superacid is partially concentrated perchloric acid, wherein the perchloric acid is present in a concentration of 60% to 72%;

heating the mixture for not more than 5 minutes, wherein the heating is conducted at a temperature range of 60°

C. to 70°

C.;

chilling the heated mixture in ice to produce a chilled mixture;

neutralizing the chilled mixture with an alkali to yield a salt precipitate wherein the alkali is selected from the group consisting of potassium hydroxide, rubidium hydroxide, caesium hydroxide, calcium hydroxide, calcium oxide, and combinations thereof;

filtering the salt precipitate off to obtain the aqueous sugar solution; and

treating the salt precipitate with sulfuric acid to yield a sulfate salt and perchloric acid, wherein the sulfate salt is selected from the group consisting of potassium sulfate, rubidium sulfate, caesium sulfate, and calcium sulfate.

2. The method of claim 1, wherein the cellulosic materials are selected from the group consisting of paper, paddy straw, wood chip, leaves, saw dust, mushroom waste, fruit skins, weeds, cotton, plywood, grass, pressed oil-palm fibres, bagasse, corn stovers, and combinations thereof.

3. The method of claim 1, wherein the weight ratio between the perchloric acid and the cellulosic materials is 4-5:

1.

4. The method of claim 1, further comprising a step of concentrating the aqueous sugar solution.

5. The method of claim 4, wherein the aqueous sugar solution is concentrated by vacuum stripping.

6. A method for synthesizing bioethanol, comprising:

mixing ground cellulosic materials with a superacid, wherein the superacid is free of periodic acid, wherein the superacid is partially concentrated perchloric acid, wherein the perchloric acid is present in a concentration of 60% to 72%;

heating the mixture for not more than 5 minutes, wherein the heating is conducted at a temperature range of 60°

C. to 70°

C.;

chilling the heated mixture in ice to produce a chilled mixture;

neutralizing the chilled mixture with an alkali to yield a salt precipitate wherein the alkali is selected from the group consisting of potassium hydroxide, rubidium hydroxide, caesium hydroxide, calcium hydroxide, calcium oxide, and combinations thereof;

filtering the salt precipitate off to obtain an aqueous sugar solution;

fermenting the aqueous sugar solution with yeast to produce bioethanol;

distilling out the bioethanol; and

treating the salt precipitate with sulfuric acid to yield a sulfate salt and perchloric acid, wherein the sulfate salt is selected from the group consisting of potassium sulfate, rubidium sulfate, caesium sulfate, and calcium sulfate.