Method for degumming hemp

A hemp degumming and degumming technology, applied in the field of hemp degumming, can solve the problems of large degumming water consumption, expensive equipment, low quality and low efficiency, etc., and achieve the effect of high raw material utilization rate, high degumming efficiency and low equipment requirements

Pending Publication Date: 2020-10-30
湖南国麻新材料科技有限责任公司
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AI Technical Summary

Problems solved by technology

The hemp products obtained by chemical degumming method and natural water retting method are of lower grade and relatively single use
Moreover, the chemical degumming method has high energy consumption, high water consumption, high pollution, and high cost; the natural water retting method occupies and pollutes water areas, has low quality and low efficiency, and is increasingly inconsistent with the theme of "survival, environmental protection, and development" advocated by people.
The method of ultrasonic degumming has the characteristics of easy degumming and good effect. The disadvantage is that the equipment used for ultrasonic degumming is relatively expensive and the investment is large.
The method of pretreating hemp with biological enzymes and then degumming it with chemical reagents has the characteristics of thorough degumming and environmental protection. The disadvantage is that the process conditions of this method are complicated and difficult to control.
The method of degumming ramie by physical and mechanical force has the advantage of protecting the environment, but its disadvantage is that it needs special mechanical equipment and the process is complicated
The disadvantage of the compound microbial degumming method is that the method needs to cultivate the strains first, and the process is relatively complicated.
The disadvantage of the microwave irradiation degumming method is that a large amount of water will be used in the degumming process, which does not fundamentally solve the problem of large water consumption for degumming, and the waste water after degumming is difficult to recycle.
[0005] Lignin is a polymer of complex organic components. Organic solvents can only dissolve part of the components, resulting in high K value of fiber products, that is, there are many lignin residues, which cannot meet the product quality requirements. Patents and research on hemp organic solvent degumming have been There are many, for example, ethanol, formic acid, acetic acid and other processes, which have problems such as high temperature, high pressure, corrosion, degumming quality, lignin residue, whiteness, etc., and have not yet been industrialized
[0006] Chinese Patent Publication No. CN101016655A, the patent titled "A Method for Preparing Textile Fibers by Degumming Environmentally Friendly Raw Hemp" discloses a method for preparing hemp fibers by degumming environmentally friendly degumming, using organic solvents to degumming hemp, which has a good degumming effect And the advantages of no alkali and no acid in the degumming process, but the organic solvents used in this method are mostly toxic substances, and the organic solvents are only used as raw materials for extracting lignin, and a large amount of water resources are still used in this degumming method, and the waste water needs to be treated. emission

Method used

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  • Method for degumming hemp

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] 1. Catalytic cooking

[0035] Choose the loose hemp after the dedusting of dry weight 10 kilograms, put into pressure cooker, add 14L water, 80L ethanol (95%), 6L creosote (produced by Shanxi Jinyuan Coal Chemical Technology Co., Ltd., density 0.98-1.01, distilled 160-180°C), heated to 150°C, kept warm for 1 hour, and then extruded to release the cooking liquid.

[0036] 2. Solvent washing

[0037] Add the hemp fiber obtained in step 1 to 70L of 95% ethanol for replacement washing, circulate for 20 minutes, extrude the solvent, then re-add new ethanol washing solvent, repeat three times, keep the washing temperature at 60°C, and then extrude detergent. Add the hemp fiber to 100L water and heat it to 95°C to evaporate the residual ethanol. The evaporated ethanol contains azeotropic water and enters the alcohol-water separation equipment for recycling and reuse of ethanol.

[0038] 3. Washing

[0039] Wash the hemp fiber obtained in step 2 with 80L of water, wash with...

Embodiment 2

[0047] 1. Catalytic cooking

[0048] Choose the dedusted open cannabis with a dry weight of 10 kg, put it into a pressure cooker, add 20L of water, 75L of industrial tetrahydrofuran, and 5L of wood phenol oil (produced by Zhiyuan Biochemical Co., Ltd., Yongan City, Fujian Province, natural phenol content (GC)> 55%, specific gravity 1.12, distillation range 180-200°C), heated to 120°C, kept for 1.5 hours, and then extruded to release the cooking liquid.

[0049] 2. Solvent washing

[0050] Add the hemp fiber obtained in step 1 to 60L tetrahydrofuran for replacement washing, circulate for 20 minutes, squeeze out the solvent, then re-add new tetrahydrofuran, repeat three times, keep the washing temperature at 40°C, and then squeeze out the washing liquid. Add the hemp fiber to 80L of water and heat it to 90°C to evaporate the residual tetrahydrofuran.

[0051] 3. Washing

[0052] The hemp fiber that step 2 obtains is washed with 80L water, carries out water washing three times...

Embodiment 3

[0060] 1. Catalytic cooking

[0061] Choose the scraped green ramie skin after dust removal with a dry weight of 10 kg, put it into a pressure cooker, add 17L water, 80L dimethylformamide, 3L wood phenol oil (produced by Zhiyuan Biochemical Co., Ltd., Yongan City, Fujian Province, natural phenol content (GC) > 55%, specific gravity 1.12, distillation range 180-200°C), heated to 150°C, kept for 0.5 hours, and then extruded to release the cooking liquid.

[0062] 2. Solvent washing

[0063] Add 80L dimethylformamide to the hemp fiber obtained in step 1 for replacement washing, circulate for 20 minutes, extrude to release the solvent, then re-add new dimethylformamide, repeat three times, keep the washing temperature at 80°C, and then extrude Squeeze out the washing liquid.

[0064] 3. Washing

[0065] The hemp fiber that step 2 obtains is washed with 80L water, carries out water washing three times, emits waste water after extruding.

[0066] 4. Bleaching

[0067] Using the...

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Abstract

The invention relates to a method for degumming hemp. According to the method, an organic solvent is used as an extraction solvent, catalysts are adopted to degum hemp raw materials and remove lignin,the extraction process comprises four steps of catalytic cooking, solvent washing, water washing and bleaching, and the catalysts are selected from creosote, crosol, kreosote and/or creosote oil. According to the method, the technical problems of high energy consumption, large amount of waste water and high damage to the fiber strength of a conventional method for degumming hemp are avoided, andthe method has the advantages of high degumming efficiency, high product whiteness, high utilization ratio of raw materials, low equipment requirement, low cost, cleanness, energy conservation, environmental friendliness and safety and is suitable for large-scale industrial production.

Description

technical field [0001] The invention relates to a method for degumming hemp, in particular to an organic solvent method for degumming hemp. Background technique [0002] my country is a big country in hemp textiles in the world, mainly including hemp crops such as ramie, flax, kenaf, jute, hemp, etc., and its planting area is about more than 400,000 hectares. With the improvement of the quality of life, people are more advocating nature and advocating "ecological textiles". The hemp fiber textile raw material has won people's favor as a clothing fabric with its unique excellent performance. However, there have always been many problems in the textile processing technology of hemp, among which the degumming process has always restricted the processing quality of hemp products, and even affected the performance of hemp textiles. Therefore, degumming is a key link in the production of hemp textiles. In addition, the conventional process only utilizes hemp fiber, and the othe...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): D01C1/00
CPCD01C1/00
Inventor 李路敏李泽民师一行张雪
Owner 湖南国麻新材料科技有限责任公司
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