Method for completely dissolving and rapidly hydrolyzing cellulose, and uses of said method

• US 9,115,215 B2
• Filed: 08/18/2010
• Issued: 08/25/2015
• Est. Priority Date: 02/02/2010
• Status: Active Grant

• Current Assignee: Xishuangbanna Tropical Botanical Garden, Chinese Academy Of Sciences
• Original Assignee: Xishuangbanna Tropical Botanical Garden, Chinese Academy Of Sciences
• Inventors: Fang, Zhen
• Primary Examiner(s): Mayes, Melvin C
• Assistant Examiner(s): COHEN, STEFANIE J
• Application Number:
  US13/259,526
• Publication Number:
  US 20120067342A1
• Time in Patent Office: 1,833 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: C08B 1/003 Preparation of cellulose solutions, i.e. dopes, with different possible solvents, e.g. ionic liquids solutions used in the manufacture of monocomponent artificial filaments or cellulose or derivatives thereof D01F2/02
• CPC Class Codes: C08B 15/02 Oxycellulose; Hydrocellulose; Cellulosehydrate, e.g. microcrystalline cellulose
• CPC Class Codes: C08L 1/02 Cellulose; Modified cellulose
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel

Abstract

The invention discloses a method for completely dissolving and rapidly hydrolyzing cellulose, and uses thereof. Cellulose is placed in an acidic aqueous solution with a [H⁺] concentration of 10⁻⁷˜1 M or an alkaline aqueous solution with a [OH⁻] concentration of 10⁻⁷˜1 M as sample A, wherein the volume ratio of solid to liquid is (0.003˜1.05):1. The acidic aqueous solution with a [H⁺] concentration of 10⁻⁷˜1 M or the alkaline aqueous solution with a [OH⁻] concentration of 10⁻⁷˜1 M is heated up to 261˜352 as sample B. Sample A and sample B obtained from step 1 and step 2 are mixed in a reactor to a concentration of cellulose of 0.1%˜35%, the concentration of the mixed solution is adjusted to an acidity of 10⁻⁷˜1 M [H⁺] or an alkalinity of 10⁻⁷˜1 M [OH⁻], and a water density of 587˜997 kg/m³, pressure is set at 6˜584 MPa. The mixture is rapidly heated up to 261˜352 at heating rate of 7.8˜14.8 /s, and then cellulose is dissolved completely in 0.8˜2 sec and hydrolyzed in 5 sec. Using this technique, it is the first time for achieving complete dissolution and rapid hydrolysis of cellulose at a lower temperature, which not only dramatically reduces the cost of hydrolysis but also improves the safety of production and extends the service life of equipment, thus possessing a good application prospect.

Claims

1. A method for completely dissolving and rapidly hydrolyzing cellulose, comprising the steps of:

(1) placing cellulose in an acidic aqueous solution with a [H⁺] concentration of 10<sup>−

7</sup>˜

1M or an alkaline aqueous solution with a [OH⁻

] concentration of 10<sup>−

7</sup>˜

1 M, as sample A, wherein the volume ratio of solid to liquid is (0.003˜

1.05);

1;

(2) heating the acidic aqueous solution with a [H⁺] concentration of 10<sup>−

7</sup>˜

1 M or an alkaline aqueous solution with a [OH⁻

] concentration of 10<sup>−

7</sup>˜

1 M up to 261˜

352°

C. as sample B;

(3) mixing sample A and sample B obtained from step 1 and step 2 in a reactor to a concentration of cellulose of 0.1%˜

35%, adjusting the concentration of the mixed solution to an acidity of 10<sup>−

7</sup>˜

1 M [H⁺] or an alkalinity of 10<sup>−

7</sup>˜

1 M [OH⁻

], and a water density of 587 997 kg/m³, setting pressure at 6˜

584 MPa, rapidly heated the mixture up to 261˜

352°

C. at a heating rate of 7.8˜

14.8°

C./s, and then completely dissolving cellulose in 0.8˜

2 sec and hydrolyzing cellulose in 5 sec.

2. The method for completely dissolving and rapidly hydrolyzing cellulose according to claim 1, wherein said acidic aqueous solution is one of hydrochloric acid, nitric acid and sulphuric acid aqueous solutions.

3. The method for completely dissolving and rapidly hydrolyzing cellulose according to claim 1, wherein said alkaline aqueous solution is one of sodium hydroxide, potassium hydroxide and calcium hydroxide aqueous solutions.

4. The method for completely dissolving and rapidly hydrolyzing cellulose according to claim 1, wherein said acidic aqueous solution is hydrochloric acid aqueous solution.

5. The method for completely dissolving and rapidly hydrolyzing cellulose according to claim 1, wherein said alkaline aqueous solution is sodium hydroxide aqueous solution.

6. The method for completely dissolving and rapidly hydrolyzing cellulose according to claim 1, further comprising producing ethanol, biofuels or value-added bioproducts from cellulose.