Method of in-situ enzymatic hydrolysis of cellulose in ionic liquid

A technology of ionic liquid and in-situ enzymatic hydrolysis, which is applied in the direction of fermentation, can solve the problems of cumbersome steps and large amount of organic solvent used for regenerated cellulose, and achieve the effects of simplifying the experimental process, overcoming the volatilization of solvents, and reducing consumption

Inactive Publication Date: 2014-08-06
QINGDAO UNIV OF SCI & TECH
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] However, this type of ionic liquid contains halogens that can inhibit the reaction of cellulase to decompose cellulose. Therefore, a common research is to use this type of imidazolium chloride salt ionic liquid to dissolve cellulose at a certain temperature, and then use water / organic solvents to dissolve the cellulose. The regenerated cellulose is regenerated, and finally the regenerated cellulose is enzymatically hydrolyzed with cellulase, which is the so-called "two-step method".

Method used

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  • Method of in-situ enzymatic hydrolysis of cellulose in ionic liquid
  • Method of in-situ enzymatic hydrolysis of cellulose in ionic liquid

Examples

Experimental program
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Embodiment 1

[0015] Microcrystalline cellulose raw material: molecular weight 25,000-50,000, degree of polymerization 153-300, ash content <0.6%, particle size 25-190 μm.

[0016] Determination method of reducing sugar content

[0017] DNS reagent: 1.6g DNS and 21g NaOH, dissolved in 200mL water, 185g potassium sodium tartrate dissolved in 500mL water, mixed with the above solution, added 5g crystalline phenol, 5g anhydrous sodium sulfite, stirred and dissolved, cooled to a constant volume in a 1000mL volumetric flask, stored Use after 7-10 days in the brown bottle.

[0018] Glucose standard curve: dry glucose at 105°C for 2 hours to constant weight, accurately weigh 0.1g, dissolve in distilled water, and set the volume to 100mL. The concentration is 1.0mg / mL. Take 10 20mL graduated test tubes with stoppers, add 0mL, 0.2mL, 0.4mL, 0.6mL, 0.8mL, 1.0mL, 1.2mL, 1.4mL, 1.6mL, 1.8mL glucose standard solution in turn, and then add Distilled water, the total volume is 2.0mL, then add 0.5mL DNS ...

Embodiment 2

[0022] Microcrystalline cellulose raw material: molecular weight 25,000-50,000, degree of polymerization 153-300, ash content <0.6%, particle size 25-190 μm.

[0023] The assay method of reducing sugar amount: refer to embodiment 1.

[0024] Add 0.5 mol (41.05 g) of N-methylimidazole and 0.5 mol (54.25 g) of chlorobutanol into a 250 mL three-necked flask equipped with a reflux device, mix well, react at 80°C for 24 hours, add 50 mL of diethyl ether to extract 4 times, and depressurize Ether is removed by distillation to obtain ionic liquid 1-hydroxybutyl, 3-methylimidazolium chloride salt ([C 4 OHmim]Cl); Then add 0.5mol (about 95g) [C 4 OHmim]Cl and 100mL of absolute ethanol were dissolved and mixed evenly, then 0.55mol (about 53.90g) of potassium acetate dissolved in absolute ethanol was added, after mixing, react at 50°C for 5h for ion exchange, and filtered under reduced pressure to form salt and unreacted salt , remove absolute ethanol by distillation under reduced pres...

Embodiment 3

[0027] Microcrystalline cellulose raw material: molecular weight 25,000-50,000, degree of polymerization 153-300, ash content <0.6%, particle size 25-190 μm.

[0028] The assay method of reducing sugar amount: refer to embodiment 1.

[0029] Add 0.5mol (41.05g) N-methylimidazole and 0.5mol (40.25g) chloroethanol into a 250mL three-neck flask equipped with a reflux device, mix well, react at 80°C for 24h, add ether 50mL to extract 4 times, and distill under reduced pressure Remove ether, obtain ionic liquid 1-hydroxyethyl, 3-methylimidazolium chloride salt ([C 2 OHmim]Cl); Then add 0.5mol (about 80g) [C 2OHmim]Cl and 100mL of absolute ethanol were dissolved and mixed evenly, then 0.55mol (about 52.80g) of sodium propionate dissolved in absolute ethanol was added, and after mixing, it was reacted at 50°C for 5h for ion exchange, and filtered under reduced pressure to form salt and unreacted Salt, decompression distillation removes dehydrated alcohol, cools and stands still and...

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Abstract

The present invention provides a method of in-situ enzymatic hydrolysis of cellulose, 1-hydroxyalkyl and 3-methyl imidazolium carboxylated ionic liquid can be taken as a reaction medium, the method comprises the following steps: putting microcrystalline cellulose in the ionic liquid at the temperature of 70 DEG C-80 DEG C to obtain a homogeneous solution, wherein the weight of cellulose accounts for 2-6% of that of ionic liquid; adding a citric acid buffer with pH value of 4.8 and cellulase at the temperature of 50-60 DEG C, wherein the addition amount of citric acid buffer accounts for 5-10% of weight of ionic liquid, cellulase is added in an amount of 1-3mg per ml of ionic liquid, and reacting for 30-60 minutes; after enzymatic hydrolysis, separating the ionic liquid and reducing sugar through an absorption resin column, wherein the recovered ionic liquid enables multiple reusage. The method of the invention is simple, compared with a traditional cellulose enzymatic hydrolysis and a current two-step method of cellulase pretreatment by ionic liquid and regenerated enzymatic hydrolysis, the present invention has the advantages of high efficiency and environmental friendly characteristic.

Description

technical field [0001] The invention relates to a method for enzymatically decomposing cellulose in situ by cellulase under the homogeneous system of ionic liquid / cellulose. Background technique [0002] Cellulose is one of the most abundant natural renewable resources in the world. The resource utilization of cellulose has always been a research hotspot and has good economic benefits and application prospects. As one of the effective ways of cellulose resource utilization, enzymatic hydrolysis can degrade cellulose into glucose, which can then be converted into ethanol, acetone, butanol and other fuels and chemical raw materials, which has attracted widespread attention. Due to the strong hydrogen bonds between and within the cellulose molecules, these hydrogen bonds make many cellulose molecules form a crystal structure together, so that the cellulose polymer shows rigidity and high water insolubility. The key to efficient conversion of cellulose is to reduce the crystall...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C12P19/14C12P19/02
Inventor 于世涛李露刘仕伟刘福胜解从霞谢娟
Owner QINGDAO UNIV OF SCI & TECH
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