Method for separating cellulose from straws and getting cellulose solution

A cellulose and aqueous solution technology, which is applied in fiber raw material processing, textile and papermaking, etc., can solve the problems of lack of research on straw cellulose, and achieve the effects of saving dosage, reducing pollution and reducing costs.

Inactive Publication Date: 2011-04-27
UNIV OF SCI & TECH OF CHINA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, these systems are currently applicable to cotton cellulose, and research on straw cellulose is still lacking.

Method used

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  • Method for separating cellulose from straws and getting cellulose solution
  • Method for separating cellulose from straws and getting cellulose solution
  • Method for separating cellulose from straws and getting cellulose solution

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] figure 1 A schematic flow chart of the present invention for separating cellulose from straw and preparing cellulose aqueous solution is given: the whole process is divided into three steps: firstly, the raw material straw biomass A is subjected to acid pretreatment to remove hemicellulose, and after filtration and separation, Obtain hemicellulose-degraded sugar solution C and residue B; then carry out delignification treatment on residue B to obtain pure cellulose D; finally dissolve the obtained cellulose with alkaline water solvent to obtain cellulose aqueous solution E. These three steps are interrelated, that is: the removal rate of hemicellulose in the first step should be greater than 85%, so as to ensure the smooth progress of the second step delignification step; similarly, the removal of lignin in the second step The ratio should be greater than 80% of its original content to ensure that the obtained cellulose has sufficient purity, and at the same time to ens...

Embodiment 2

[0041] In this example, 10 grams of dewaxed bagasse powder was first added to the reactor, and 150 ml of phosphoric acid aqueous solution with a concentration of 8 mol / L was added, followed by reaction at 80° C. for 3 hours. After cooling, it was filtered, and the filter cake was washed with deionized water and ethanol, and dried at 55°C. Add subsequently in the aqueous solution of 25% PEG-4000 in 100 milliliters, also contain 7.0wt% NaOH, 3.9wt% NaOH simultaneously in this aqueous solution 2 S and 2.1 wt% Na 2 CO 3 . Heat the reaction at 180° C. for 1.5 hours, then cool, filter, wash, and dry to obtain cellulose powder.

[0042] Add 3 grams of the resulting cellulose powder into 50 milliliters of a mixture aqueous solution of 4-10wt% lithium hydroxide / 4-15wt% urea (or 4-15wt% thiourea) as a solvent, stir for 30 minutes, and put Pre-cool in a refrigerator at -20°C for 12 hours, take out and melt, and stir until a uniform cellulose solution is obtained.

Embodiment 3

[0044] In this example, 12 grams of dewaxed rice straw powder was first added to the reactor, and 200 ml of sulfuric acid aqueous solution with a concentration of 2 mol / L was added, and then reacted at 100° C. for 5 hours. After cooling, it was filtered, and the filter cake was washed with deionized water and ethanol, and dried at 55°C. Add subsequently in the aqueous solution of 30% PEG-500 in 150 milliliters, also contain 7.0wt% NaOH, 3.1wt%wt%Na in this aqueous solution simultaneously 2 S and 2.1 wt% Na 2 CO 3 . Heat the reaction at 100°C for 6 hours, then cool, filter, wash, and dry to obtain cellulose powder.

[0045] Add 3 grams of the cellulose powder obtained above to 80 milliliters of a mixture aqueous solution of 4-10wt% lithium hydroxide / 4-15wt% urea (or 4-15wt% thiourea) as a solvent, stir for 30 minutes, and put Pre-cool in a refrigerator at -20°C for 12 hours, then remove and melt, and combine with vigorous stirring to obtain a uniform cellulose solution.

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Abstract

The invention discloses a method for separating cellulose from straws and getting cellulose solution, which is characterized in that the straws are dipped into inorganic acid of 2-8 mol / L to enable thThe invention discloses a method for separating cellulose from straws and getting cellulose solution, which is characterized in that the straws are dipped into inorganic acid of 2-8 mol / L to enable the hemicellulose desorption ratio to reach over 85wt percent, then the straw residues for desorbing hemicelluloses are added in water solution containing 20-30wt percent of polyoxyalkylene and 12-13wte hemicellulose desorption ratio to reach over 85wt percent, then the straw residues for desorbing hemicelluloses are added in water solution containing 20-30wt percent of polyoxyalkylene and 12-13wtpercent of sodium hydroxide, sodium sulfide and sodium carbonate with the mol ratio of 0.5-1.5:0.2-1.0:0.1-0.3 and extracted till the lignin desorption ratio is larger than 80wt percent; every 3-4g ofpercent of sodium hydroxide, sodium sulfide and sodium carbonate with the mol ratio of 0.5-1.5:0.2-1.0:0.1-0.3 and extracted till the lignin desorption ratio is larger than 80wt percent; every 3-4g ofgot cellulose is added into 6-10wt percent of sodium hydroxide containing 0-100ml or 4-10wt percent of lithium hydroxide, and 4-15wt percent of carbamide or thiourea solution to realize that the stra got cellulose is added into 6-10wt percent of sodium hydroxide containing 0-100ml or 4-10wt percent of lithium hydroxide, and 4-15wt percent of carbamide or thiourea solution to realize that the straws are directly prepared into the cellulose solution through precooling at low temperature, melting and stirring. The method can be used for cellulose spanning, regeneration membrane and resin manufacws are directly prepared into the cellulose solution through precooling at low temperature, melting and stirring. The method can be used for cellulose spanning, regeneration membrane and resin manufacture and chemical derivation reaction.ture and chemical derivation reaction.

Description

technical field [0001] The invention belongs to the technical field of using biomass to prepare cellulose-based products, and in particular relates to a method for separating cellulose from straw and dissolving it in a water-based solvent to obtain an aqueous solution of cellulose Background technique [0002] Biomass has been attracting much attention as an alternative resource, and its potential applications include synthesis of renewable energy and chemicals. Cellulose is the main component of biomass and the most abundant biopolymer in the biosphere. It is a valuable raw material, so how to separate cellulose from biomass is an important issue. In the process of preparing cellulose from wood pulp reported in U.S. Patent 0145351A1 (2005), the wood pulp used is respectively from kraft wood pulp, soda boiled wood pulp, organic solvent wood pulp and steam explosion wood pulp. The wood pulp is further bleached and hydrolyzed to obtain a pure cellulose product. However, the ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): D21C5/00C08H5/00C08J3/03
Inventor 闫立峰顾青
Owner UNIV OF SCI & TECH OF CHINA
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