CN114086414A - A kind of lignocellulose pulping method based on acidic deep eutectic solvent - Google Patents
A kind of lignocellulose pulping method based on acidic deep eutectic solvent Download PDFInfo
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- CN114086414A CN114086414A CN202111246328.8A CN202111246328A CN114086414A CN 114086414 A CN114086414 A CN 114086414A CN 202111246328 A CN202111246328 A CN 202111246328A CN 114086414 A CN114086414 A CN 114086414A
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- eutectic solvent
- lignocellulose
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- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C3/00—Pulping cellulose-containing materials
- D21C3/003—Pulping cellulose-containing materials with organic compounds
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
- D21C9/02—Washing ; Displacing cooking or pulp-treating liquors contained in the pulp by fluids, e.g. wash water or other pulp-treating agents
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- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21D—TREATMENT OF THE MATERIALS BEFORE PASSING TO THE PAPER-MAKING MACHINE
- D21D5/00—Purification of the pulp suspension by mechanical means; Apparatus therefor
- D21D5/02—Straining or screening the pulp
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- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H11/00—Pulp or paper, comprising cellulose or lignocellulose fibres of natural origin only
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H11/00—Pulp or paper, comprising cellulose or lignocellulose fibres of natural origin only
- D21H11/12—Pulp from non-woody plants or crops, e.g. cotton, flax, straw, bagasse
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Wood Science & Technology (AREA)
- Paper (AREA)
Abstract
The invention belongs to the technical field of pulping process, and discloses a lignocellulose pulping method based on an acidic eutectic solvent, which mainly comprises the following steps: slicing and dedusting lignocellulose; mixing lignocellulose and a eutectic solvent, adding the mixture into a normal-pressure reaction kettle, and carrying out a cooking reaction; after the cooking is finished, adding a washing solution to dilute the mixture, performing solid-liquid separation to obtain coarse pulp, and washing the coarse pulp with the washing solution again; and finally, screening by using a pulp screening machine to obtain fine pulp. According to the invention, the excellent lignin and hemicellulose removing effect of benzyltriethylammonium chloride/formic acid is utilized, so that the effective separation of fibers under the conditions of normal pressure and low temperature is realized, the energy consumption and acid consumption required by cooking are obviously reduced, and the requirement on reaction equipment is reduced; in addition, the low eutectic solvent and the washing liquid in the method can be recycled, so that the burden of subsequent pollution treatment is reduced; therefore, the method has economic and environmental feasibility.
Description
Technical Field
The invention belongs to the technical field of pulping processes, and particularly relates to a clean pulping method of an acidic eutectic solvent under the conditions of normal pressure and low temperature.
Background
With the rapid development of socioeconomic of China, the demand of paper is steadily increasing. But at the same time, the pulping industry in China still has the problems of over high energy consumption and higher subsequent pollution treatment cost. The development of the pulping method with low energy consumption and environmental protection is a necessary way for the sustainable development of the pulping and papermaking industry.
Organic solvent pulping has been extensively studied for its excellent chemical recycling properties, with formic acid pulping being one of the more mature methods. According to the method for producing paper pulp by adopting formic acid as a main cooking chemical agent disclosed in the patent CN1299424A, the required cooking temperature is between 110 and 140 ℃, is far lower than the temperature (130 to 190 ℃) required by cooking other organic solvents, and the used formic acid can be obtained again by distillation; however, the acid consumption required by the method is up to 75-90%, and the method needs to be carried out under the condition of belt pressure, and has high requirements on corrosion resistance and pressure resistance of equipment.
In recent years, eutectic solvents (DESs) attract people's attention as a new green organic solvent, and the eutectic solvents are formed by combining a hydrogen bond donor and a hydrogen bond acceptor, can be recycled, and have the advantages of low vapor pressure, low melting point, strong controllability and the like. Research shows that the acidic eutectic solvent can decompose a three-dimensional network structure in the lignocelluloses under the conditions of normal pressure and low temperature, and the separation of fibers is realized. Therefore, the introduction of the acidic eutectic solvent is expected to realize pulping under the conditions of less acid consumption and milder conditions, thereby not only reducing the production cost, but also conforming to the concept of green development. In patent CN108660837A, a choline chloride and lactic acid eutectic solvent is adopted to cook poplar chips under the normal pressure condition, so that slurry with the alpha-cellulose content of 83.5% can be obtained, but the treatment temperature of the technology is as high as 150 ℃, and the treatment time is as long as 10 hours; the harsh conditions cause high energy consumption and great damage to the fiber, and the polymerization degree of the obtained fiber is only 547, so that the industrialization of the fiber is limited. Therefore, the development of a lignocellulose pulping method based on an acid eutectic solvent is still a problem to be solved at present.
Disclosure of Invention
The invention aims to provide a clean pulping method under normal pressure and low temperature by utilizing an acidic eutectic solvent, and solves the problems of high energy consumption, strict equipment requirement, large chemical consumption and high subsequent pollution treatment cost in the existing pulping process.
The technical scheme adopted by the invention is implemented according to the following steps:
a clean pulping method using an acidic eutectic solvent at normal pressure and low temperature specifically comprises the following steps:
step 1: mixing a lignocellulose raw material and a eutectic solvent, and then carrying out a cooking reaction; after the cooking is finished, obtaining a mixture of the low eutectic solvent and the coarse pulp;
step 2: adding a washing solution into the mixture for dilution, then carrying out solid-liquid separation to respectively obtain a eutectic solvent and the coarse pulp, and continuously washing the coarse pulp by using the washing solution;
and step 3: and screening the coarse pulp by using a pulp screening machine to respectively obtain pulp residue and fine pulp.
Further, the lignocellulose raw material in the step 1 is wood, bamboo or grass raw material.
Preferably, the lignocellulose raw material is eucalyptus board skin, and the form of the eucalyptus board skin is 2-3cm long, 1-2cm wide and 0.5cm thick.
Further, before use, the lignocellulose raw material is subjected to slicing, dust removal and air drying treatment.
Further, the eutectic solvent in the step 1 is a mixture of benzyltriethylammonium chloride and formic acid, and the molar ratio of the two components is 1: 4-1: 6.
Further, the solid-to-liquid ratio of the lignocellulose raw material and the eutectic solvent in the step 1 is 1: 10-1: 20, the cooking temperature is 120-140 ℃, and the cooking time is 1-3 hours.
Further, the washing solution in step 2 is at least one of acetone, ethanol and water.
Further, the screen plate of the screen used in the step 3 has a screen gap of 0.1-0.25 mm.
Compared with the existing pulping method, the invention has the following advantages and effects.
(1) In the pulping method provided by the invention, the selected eutectic solvent has low cost, is non-toxic and can be recycled, the consumption of chemicals in pulping is reduced, the subsequent pollution treatment burden is lightened, and the method is economic and environment-friendly.
(2) The pulping method provided by the invention has relatively low requirements on equipment, and the cooking reaction can be finished in a normal-pressure reaction kettle.
(3) The pulping method provided by the invention has the advantages that the temperature required by cooking is obviously reduced, and the energy consumption requirement is greatly reduced.
Detailed Description
The present invention is described in detail with reference to the following embodiments, but the embodiments of the invention are not limited to the specific examples, and other changes, modifications, substitutions, combinations, and simplifications which do not depart from the technical spirit of the invention should be regarded as equivalent substitutions, and all fall within the scope of the technical solution of the invention. The instruments and medicines used are not indicated by manufacturers, and can be regarded as conventional products which can be purchased commercially.
Example 1
A lignocellulose pulping method based on an acidic eutectic solvent comprises the following steps:
the benzyltriethylammonium chloride and formic acid are mixed according to the molar ratio of 1:5, and are magnetically stirred at the temperature of 25 ℃ to form a uniform transparent liquid eutectic solvent. Cutting eucalyptus wood veneer into wood pieces with length of 2-3cm, width of 1-2cm and thickness of 0.5cm, cleaning surface silt with clear water, air drying in indoor environment for 3 days, measuring water content, and placing in a sealed bag for use.
Respectively weighing 10.00g of eucalyptus wood veneer (absolute dry) and 100g of eutectic solvent, mixing and adding into a normal pressure reaction kettle for stewing reaction, wherein the stewing time is 1.5h, and the stewing temperature is 130 ℃. And after the cooking is finished, adding 100ml of water to dilute the solid-liquid mixture, filtering the mixture by using a 200-mesh pulp bag to obtain a eutectic solvent and coarse pulp respectively, washing the coarse pulp by using 300ml of water again, and screening the coarse pulp by using a flat vibrating screen with a screen gap of 0.15mm to obtain fine pulp. The coarse pulp yield was calculated to be 58.91%, the fine pulp yield was 50.67%, the fiber length weighted average length was 0.572mm, and the fine fiber area ratio was 16.97%.
Example 2
A lignocellulose pulping method based on an acidic eutectic solvent comprises the following steps:
the benzyltriethylammonium chloride and formic acid are mixed according to the molar ratio of 1:5, and are magnetically stirred at the temperature of 25 ℃ to form a uniform transparent liquid eutectic solvent. Cutting eucalyptus wood veneer into pieces with length of 2-3cm, width of 1-2cm and thickness of 0.5cm, cleaning surface silt with clear water, air drying in indoor environment for 3 days, measuring water content, and placing in a sealed bag for use.
Respectively weighing 10.00g of eucalyptus wood veneer (absolute dry) and 100g of eutectic solvent, mixing and adding into a normal pressure reaction kettle for stewing reaction, wherein the stewing time is 2.0h, and the stewing temperature is 130 ℃. And after the cooking is finished, 200ml of ethanol is added to dilute the solid-liquid mixture, then the mixture is filtered by using a 200-mesh pulp bag to respectively obtain a eutectic solvent and coarse pulp, the coarse pulp is washed by using 200ml of ethanol again, and then the coarse pulp is screened by using a flat vibrating screen with a screen gap of 0.15mm to obtain fine pulp. The calculation shows that the yield of the coarse pulp is 54.32 percent, the yield of the fine pulp is 52.38 percent, the weighted average length of the fiber length is 0.516mm, and the area ratio of the fine fiber is 11.37 percent.
Example 3
A lignocellulose pulping method based on an acidic eutectic solvent comprises the following steps:
the benzyltriethylammonium chloride and formic acid are mixed according to the molar ratio of 1:5, and are magnetically stirred at the temperature of 25 ℃ to form a uniform transparent liquid eutectic solvent. Cutting eucalyptus wood veneer into wood pieces with length of 2-3cm, width of 1-2cm and thickness of 0.5cm, cleaning surface silt with clear water, air drying in indoor environment for 3 days, measuring water content, and placing in a sealed bag for use.
Respectively weighing 10.00g of eucalyptus wood veneer (absolute dry) and 100g of eutectic solvent, mixing and adding into a normal pressure reaction kettle for cooking reaction, wherein the cooking time is 2.5h, the cooking temperature is 130 ℃, and the stirring speed is 200 r/min. After cooking, 200ml of acetone is added to dilute the solid-liquid mixture, then the mixture is filtered by using a 200-mesh pulp bag to obtain a eutectic solvent and coarse pulp respectively, the coarse pulp is washed by 200ml of washing solution acetone again, and then the coarse pulp is screened by using a flat vibrating screen with a screen gap of 0.15mm to obtain fine pulp. The yield of the brown stock is 50.83 percent, the yield of the fine stock is 50.54 percent, the weighted average fiber length is 0.482mm, and the area ratio of the fine fiber is 30.70 percent.
Example 4
A lignocellulose pulping method based on an acidic eutectic solvent comprises the following steps:
the benzyltriethylammonium chloride and formic acid are mixed according to the molar ratio of 1:5, and are magnetically stirred at the temperature of 25 ℃ to form a uniform transparent liquid eutectic solvent. Cutting eucalyptus wood veneer into pieces with length of 2-3cm, width of 1-2cm and thickness of 0.5cm, cleaning surface silt with clear water, air drying in indoor environment for 3 days, measuring water content, and placing in a sealed bag for use.
Respectively weighing 10.00g of eucalyptus wood veneer (absolute dry) and 100g of eutectic solvent, mixing and adding into a normal pressure reaction kettle for stewing reaction, wherein the stewing time is 3.0h, and the stewing temperature is 130 ℃. After cooking, 200ml of ethanol/water solution (v/v ═ 1:1) is added to dilute the solid-liquid mixture, then the mixture is filtered by using a 200-mesh pulp bag to obtain a eutectic solvent and coarse pulp respectively, the coarse pulp is washed by using 200ml of ethanol/water solution (v/v ═ 1:1) again, and then the coarse pulp is screened by using a flat vibrating screen with a screen gap of 0.15mm to obtain fine pulp. The calculation shows that the yield of the coarse pulp is 48.53 percent, the yield of the fine pulp is 48.05 percent, the weighted average length of the fiber length is 0.401mm, and the area ratio of the fine fiber is 42.65 percent.
Comparative example 1
Pulping with formic acid alone:
respectively weighing 10.00g of eucalyptus wood veneer (oven-dried) and 100g of formic acid solution, mixing, adding into a normal pressure reaction kettle, and performing cooking reaction for 2.0h at 130 ℃. After the cooking is finished, the eucalyptus board veneer wood chips basically keep the original shape and are not dispersed into fibers, so that the purpose of pulping cannot be achieved.
Comparative example 2
Pulping with benzyltriethylammonium chloride alone:
because the melting point of the benzyltriethylammonium chloride is 239 ℃, the benzyltriethylammonium chloride still exists in a solid form at the temperature of 130 ℃, and the purpose of pulping cannot be achieved.
Claims (8)
1. A lignocellulosic pulping process based on an acidic eutectic solvent, the process comprising the steps of:
(1) mixing a lignocellulose raw material and a eutectic solvent, and then carrying out a cooking reaction; after the cooking is finished, a mixture of the eutectic solvent and the coarse pulp is obtained;
(2) adding a washing solution into the mixture for dilution, then carrying out solid-liquid separation to respectively obtain a eutectic solvent and the coarse pulp, and continuously washing the coarse pulp by using the washing solution;
(3) screening the coarse pulp by using a pulp screening machine to respectively obtain pulp residue and fine pulp;
the low eutectic solvent in the step (1) is a mixture of benzyltriethylammonium chloride and formic acid.
2. The lignocellulose pulping method based on the acidic eutectic solvent as claimed in claim 1, wherein the molar ratio of the benzyltriethylammonium chloride to the formic acid in the step (1) is 1: 4-1: 6.
3. The lignocellulose pulping method based on the acidic eutectic solvent as claimed in claim 1, wherein the solid-to-liquid ratio of the lignocellulose raw material and the eutectic solvent in the step (1) is 1: 10-1: 20.
4. The lignocellulose pulping method based on the acidic eutectic solvent according to claim 1, wherein the cooking temperature in the step (1) is 120-140 ℃, and the cooking time is 1-3 h.
5. The lignocellulose pulping method based on the acidic eutectic solvent according to claim 1, wherein the lignocellulose raw material in the step (1) is wood, bamboo or grass raw material.
6. The lignocellulose pulping method based on the acidic eutectic solvent as claimed in claim 1, wherein the lignocellulose raw material in the step (1) is eucalyptus wood veneer, which is 2-3cm long, 1-2cm wide and 0.5cm thick.
7. The method for pulping lignocellulose based on an acidic eutectic solvent according to claim 1, wherein the washing liquid in the step (2) is at least one of acetone, ethanol and water.
8. The lignocellulose pulping method based on the acidic eutectic solvent according to claim 1, wherein the screen plate screen slot of the screen used in the step (3) is 0.1-0.25 mm.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114808503A (en) * | 2022-06-08 | 2022-07-29 | 陕西科技大学 | Method for improving quality of dissolving pulp based on microwave-assisted eutectic solvent |
| CN114960254A (en) * | 2022-06-08 | 2022-08-30 | 陕西科技大学 | Method for preparing high-quality bamboo dissolving pulp through pulp screening and eutectic solvent treatment |
| CN114990917A (en) * | 2022-05-19 | 2022-09-02 | 华南理工大学 | A kind of cooking method for preparing bamboo lyocell fiber grade dissolving pulp |
| CN116200959A (en) * | 2023-02-27 | 2023-06-02 | 湖南康业生物科技有限公司 | Clean pulping process for bamboo and straw |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2876202A1 (en) * | 2013-11-25 | 2015-05-27 | CEPI aisbl | Use of deep eutectic solvents in the production of paper |
| CN105908550A (en) * | 2016-06-12 | 2016-08-31 | 华南理工大学 | Method for separating and extracting lignin from eucalyptus |
| CN108660837A (en) * | 2018-05-29 | 2018-10-16 | 南京林业大学 | The separation method of three component of cellulose, hemicellulose and lignin in one plant fiber raw material |
| CN108950091A (en) * | 2018-07-31 | 2018-12-07 | 河北科技大学 | A kind of eutectic solvent, preparation method and the application in glucose is prepared in hydrocellulose |
| CN110172160A (en) * | 2019-05-10 | 2019-08-27 | 北京林业大学 | A kind of separation method of high Vinsol |
| CN112899313A (en) * | 2021-03-23 | 2021-06-04 | 华南理工大学 | Acidic eutectic solvent, preparation and application thereof in pretreatment of straws to improve enzymolysis efficiency |
-
2021
- 2021-10-26 CN CN202111246328.8A patent/CN114086414A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2876202A1 (en) * | 2013-11-25 | 2015-05-27 | CEPI aisbl | Use of deep eutectic solvents in the production of paper |
| CN105908550A (en) * | 2016-06-12 | 2016-08-31 | 华南理工大学 | Method for separating and extracting lignin from eucalyptus |
| CN108660837A (en) * | 2018-05-29 | 2018-10-16 | 南京林业大学 | The separation method of three component of cellulose, hemicellulose and lignin in one plant fiber raw material |
| CN108950091A (en) * | 2018-07-31 | 2018-12-07 | 河北科技大学 | A kind of eutectic solvent, preparation method and the application in glucose is prepared in hydrocellulose |
| CN110172160A (en) * | 2019-05-10 | 2019-08-27 | 北京林业大学 | A kind of separation method of high Vinsol |
| CN112899313A (en) * | 2021-03-23 | 2021-06-04 | 华南理工大学 | Acidic eutectic solvent, preparation and application thereof in pretreatment of straws to improve enzymolysis efficiency |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114990917A (en) * | 2022-05-19 | 2022-09-02 | 华南理工大学 | A kind of cooking method for preparing bamboo lyocell fiber grade dissolving pulp |
| CN114808503A (en) * | 2022-06-08 | 2022-07-29 | 陕西科技大学 | Method for improving quality of dissolving pulp based on microwave-assisted eutectic solvent |
| CN114960254A (en) * | 2022-06-08 | 2022-08-30 | 陕西科技大学 | Method for preparing high-quality bamboo dissolving pulp through pulp screening and eutectic solvent treatment |
| CN116200959A (en) * | 2023-02-27 | 2023-06-02 | 湖南康业生物科技有限公司 | Clean pulping process for bamboo and straw |
| CN116200959B (en) * | 2023-02-27 | 2024-04-19 | 湖南康业生物科技有限公司 | Clean pulping process for bamboo and straw |
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Application publication date: 20220225 |