CN110684204A - Method for separating wood fiber by organic acid and homologously preparing furfural - Google Patents
Method for separating wood fiber by organic acid and homologously preparing furfural Download PDFInfo
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- CN110684204A CN110684204A CN201910900087.0A CN201910900087A CN110684204A CN 110684204 A CN110684204 A CN 110684204A CN 201910900087 A CN201910900087 A CN 201910900087A CN 110684204 A CN110684204 A CN 110684204A
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- C08H8/00—Macromolecular compounds derived from lignocellulosic materials
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- C07D307/00—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom
- C07D307/02—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings
- C07D307/34—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members
- C07D307/38—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members with substituted hydrocarbon radicals attached to ring carbon atoms
- C07D307/40—Radicals substituted by oxygen atoms
- C07D307/46—Doubly bound oxygen atoms, or two oxygen atoms singly bound to the same carbon atom
- C07D307/48—Furfural
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Abstract
The invention belongs to the field of efficient utilization of biomass, and discloses a method for separating wood fiber from organic acid and homologously preparing furfural. The method can efficiently separate lignin, cellulose and hemicellulose. The method comprises the following steps: drying and crushing wood fibers; reacting wood fiber powder with organic acid at 50-120 ℃ for 10-90 min; after the reaction is finished, adding cold water to terminate the reaction; and then filtering to obtain a solid part and a liquid part, wherein the solid part is cellulose, the liquid part is diluted by pure water, centrifuged, precipitated and separated to obtain high-purity lignin, and the liquid is pentose hydrolyzed by hemicellulose. The method can efficiently separate three major components of the wood fiber, utilizes the strong acid of the organic acid and has no oxidability, and has low biomass loss rate. The dissolved hemicellulose is heated by organic acid which is separated and utilized and is converted into furfural with high efficiency by autocatalysis, and the organic acid solution is concentrated and recycled, so that a green recycling treatment process is realized, and a basis is provided for high-value utilization of biomass.
Description
Technical Field
The invention belongs to the field of efficient utilization of biomass, and particularly relates to a method for separating wood fibers from organic acid and homologously preparing furfural.
Background
With the increasing consumption of non-renewable resources and the increasing demand for chemicals of petroleum refining derivative platforms, the development of alternative green energy sources is urgently needed. As a renewable resource, the biomass has the characteristics of wide source, large reserve, environmental friendliness and the like. The biomass resources are mainly derived from urban garbage, agricultural and forestry wastes such as straws, wood chips and branches, the annual output of the biomass resources reaches 1700 hundred million tons, 50 hundred million tons of petroleum are consumed each year, 200 hundred million tons of coal are consumed, and if the wood fiber resources are efficiently utilized, the immeasurable effect on energy economy is brought.
A large amount of wood fiber wastes are mainly buried and decomposed, are burnt on the spot and the like in the current treatment mode, have low utilization rate and are waste of natural renewable resources. The pretreatment is a key step for the efficient utilization of biomass, is one of the most expensive steps in the whole operation process, and has great influence on the utilization of the following three components of lignin, hemicellulose and cellulose.
The wood fiber is a natural three-dimensional network high molecular polymer, wherein the lignin is a binder and plays a role in protection and support. Thus, delignification is a critical step in the overall pretreatment. The pretreatment method of wood fiber is many and can be divided into physical method, chemical method, biological method and their combined method. However, the treatment time of a plurality of pretreatment methods is long, the temperature is high, the energy input is large, the operation cost is high, and certain corrosion is caused to equipment, so that the large-scale application of biomass resources is limited. Therefore, a new green solvent with circular economy is urgently needed to be developed for effectively treating and separating the wood fiber.
Disclosure of Invention
In order to overcome the defects that the existing lignocellulose biomass separation technology has long processing time, generates a large amount of waste acid and waste alkali to cause environmental pollution and high operation cost, and has low efficiency of preparing furfural by separating hemicellulose from biomass, the invention mainly aims to provide a method for separating lignocellulose from organic acid and homologously preparing furfural; the method is characterized in that a three-dimensional network structure of wood fibers is destroyed, so that cellulose and lignin are efficiently separated, a basis is provided for high-value utilization, and the hemicellulose is used for preparing high-purity furfural by a simple process of heating by homologous organic acid; the method has the advantages of low operation temperature, short treatment time, capability of realizing rapid lignification removal, low cost of the organic acid reagent, recycling and regeneration, great application value and considerable market scene.
The purpose of the invention is realized by the following technical scheme:
a method for separating wood fiber by organic acid and preparing furfural by homology comprises the following operation steps: drying the wood fiber, and crushing for later use; adding organic acid into the wood fiber powder, wherein the liquid-solid ratio of the organic acid to the wood fiber powder is (8-30) mL: 1g, treating the wood fiber powder by adopting an oil bath heating method, stirring and reacting at 50-120 ℃ for 10-90 min, and adding cold water to dilute after the reaction is finished to terminate the reaction; carrying out vacuum separation on the reaction system at room temperature to obtain a solid part and a liquid part, wherein the solid part is cellulose; diluting the liquid part with pure water, centrifuging, precipitating, and separating to obtain lignin with purity of above 90%, and the supernatant is pentose hydrolyzed from hemicellulose.
The wood fiber is more than one of straw, bagasse, corncob, wood chip and rice straw.
The organic acid is a solution with the mass concentration fraction of 50-85%, and specifically is more than one of maleic acid, formic acid, acetic acid, p-toluenesulfonic acid, oxalic acid and phosphoric acid.
The stirring reaction time is 10-90 min.
The amount of cold water used for terminating the reaction by adding cold water is 20-40 mL per 2g of the wood fiber powder.
The liquid part is diluted by pure water, centrifugally precipitated and separated, and the method specifically comprises the following steps: diluting the liquid part until the mass fraction of the acid is 2-10%, transferring the liquid part into a centrifugal machine, centrifuging the liquid part for 5-15min at 3000-8000 r to obtain a precipitate, namely lignin, and freeze-drying the precipitate for later use; heating the obtained supernatant to 100 ℃, carrying out autocatalysis by using organic acid as a catalyst to prepare furfural, and then carrying out rotary evaporation and concentration on the solution to obtain an organic acid solution for recycling.
Compared with the prior art, the invention has the following advantages and effects:
(1) the method creatively utilizes the property of the organic acid to treat and separate the wood fiber, has simple experimental process, convenient operation, low price, greenness and recyclability of the aqueous solution of the organic acid, can realize the high-efficiency lignification removal process, has the treatment effect equivalent to that of the traditional alkaline pulp at 150 ℃ for 2 hours, greatly reduces the treatment and separation cost, has extremely high application value and wide market prospect.
(2) The lignin obtained based on organic acid treatment has high purity, more than 90 percent of lignin is removed, the accessibility of cellulase to cellulose is increased, and the subsequent enzymolysis efficiency is greatly increased.
(3) The method disclosed by the invention can be used for efficiently separating three major components of the wood fiber, and the loss rate of the biomass is low by utilizing the strong acid of the organic acid and the property of no oxidability; the dissolved hemicellulose is heated by organic acid which is separated and utilized and is converted into furfural with high efficiency by autocatalysis, and the organic acid solution is concentrated and recycled, so that a green recycling treatment process is realized, and a basis is provided for high-value utilization of biomass.
Drawings
FIG. 1 is a micrograph of bagasse fibers before and after separation from bagasse by the method of the present invention, wherein (a) is a micrograph of bagasse fibers which have not been treated with an organic acid, and (b) is a micrograph of bagasse fibers which have been treated with an organic acid.
FIG. 2 is FTI R spectrum analysis before and after bagasse is treated and separated by the method of the present invention.
Detailed description of the invention
The present invention will be described in further detail with reference to examples, but the embodiments of the present invention are not limited thereto.
The raw materials in the examples are all commercially available; reagents, methods and apparatus used in the present invention are conventional in the art unless otherwise indicated.
Example 1
Weighing 2g of 40-60-mesh straw in a beaker, adding 16mL of p-toluenesulfonic acid aqueous solution with the mass concentration of 75%, carrying out oil bath reaction for 10min at 50 ℃, adding 20mL of deionized water after the reaction is finished, carrying out vacuum separation on the reaction system at room temperature to obtain two parts, namely solid and liquid, washing the solid part to be neutral for many times by using distilled water, carrying out freeze drying to obtain cellulose, and placing the cellulose in a drying box for later use. Collecting liquid part, recording volume, diluting to 2%, centrifuging at 5000r for 5min to obtain precipitate as lignin; heating the obtained supernatant to 100 ℃, carrying out autocatalysis by using organic acid as a catalyst to prepare furfural, and then carrying out rotary evaporation and concentration on the solution to obtain an organic acid solution for recycling.
Example 2
Weighing 2g of 40-60-mesh straw in a beaker, adding 30mL of 65% phosphoric acid aqueous solution, carrying out oil bath reaction at 80 ℃ for 60min, adding 25mL of deionized water after the reaction is finished, carrying out vacuum separation on the reaction system at room temperature to obtain two parts, namely solid and liquid, washing the solid part to be neutral for many times by using distilled water, carrying out freeze drying to obtain cellulose, and placing the cellulose in a drying box for later use. Collecting liquid part, recording volume, diluting to 5%, centrifuging at 3000r for 15min to obtain precipitate as lignin; heating the obtained supernatant to 100 ℃, carrying out autocatalysis by using organic acid as a catalyst to prepare furfural, and then carrying out rotary evaporation and concentration on the solution to obtain an organic acid solution for recycling.
Example 3
Weighing 2g of 40-60-mesh bagasse in a beaker, adding 40mL of 60% maleic acid aqueous solution, carrying out oil bath reaction at 100 ℃ for 70min, adding 30mL of deionized water after the reaction is finished, carrying out vacuum separation on the reaction system at room temperature to obtain two parts, namely solid and liquid, washing the solid part to be neutral for many times by using distilled water, carrying out freeze drying to obtain cellulose, and placing the cellulose in a drying box for later use. Collecting liquid part, recording volume, diluting to 7%, centrifuging at 8000r for 5min to obtain precipitate as lignin; heating the obtained supernatant to 100 ℃, carrying out autocatalysis by using organic acid as a catalyst to prepare furfural, and then carrying out rotary evaporation and concentration on the solution to obtain an organic acid solution for recycling.
The micrographs of the bagasse before and after the treatment and separation by the method of the invention are shown in figure 1, and it can be seen from the figure that bagasse fiber bundles which are not treated by organic acid are orderly arranged, compact in structure and smooth and flat in surface; after organic acid treatment, the surface of the cellulose becomes rough and uneven due to degradation and dissolution of lignin and hemicellulose, and a plurality of gully holes appear, so that the fiber bundles inside are exposed.
FTI R spectrum analysis before and after bagasse is treated and separated by the method disclosed by the invention is shown in figure 2, and structural changes of bagasse components can be analyzed by the FTI R spectrum. 1734cm-1The absorption peak is the carbonyl characteristic absorption peak of hemicellulose in the bagasse raw material, and the peak intensity almost disappears after pretreatment, which shows that hemicellulose water is removed in the treatment and separation process. 1513cm-1The method is a characteristic absorption peak of a lignin aromatic ring of a bagasse raw material, and the strength of the peak becomes weak after pretreatment and separation, which shows that the lignin removal effect is good after organic acid treatment.
Example 4
Weighing 2g of straw of 40-60 meshes, putting the straw into a beaker, adding 50mL of oxalic acid aqueous solution with the mass concentration of 55%, carrying out oil bath reaction at 110 ℃ for 80min, adding 35mL of deionized water after the reaction is finished, carrying out vacuum separation on the reaction system at room temperature to obtain two parts of solid and liquid, washing the solid part to be neutral for many times by distilled water, carrying out freeze drying to obtain cellulose, and placing the cellulose in a drying box for later use. Collecting liquid part, recording volume, diluting to 8%, centrifuging at 5000r for 10min to obtain precipitate as lignin; heating the obtained supernatant to 100 ℃, carrying out autocatalysis by using organic acid as a catalyst to prepare furfural, and then carrying out rotary evaporation and concentration on the solution to obtain an organic acid solution for recycling.
Example 5
Weighing 2g of 40-60-mesh sawdust in a beaker, adding 60mL of acetic acid aqueous solution with the mass concentration of 55%, carrying out oil bath reaction at 120 ℃ for 90min, adding 40mL of deionized water after the reaction is finished, carrying out vacuum separation on the reaction system at room temperature to obtain two parts, namely solid and liquid, washing the solid part to be neutral for many times through distilled water, carrying out freeze drying to obtain cellulose, and placing the cellulose in a drying box for later use. Collecting liquid part, recording volume, diluting to 10%, centrifuging at 5000r for 15min to obtain precipitate as lignin; heating the obtained supernatant to 100 ℃, carrying out autocatalysis by using organic acid as a catalyst to prepare furfural, and then carrying out rotary evaporation and concentration on the solution to obtain an organic acid solution for recycling.
The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.
Claims (6)
1. A method for separating wood fiber by organic acid and preparing furfural by homology is characterized by comprising the following operation steps: drying the wood fiber, and crushing for later use; adding organic acid into the wood fiber powder, wherein the liquid-solid ratio of the organic acid to the wood fiber powder is (8-30) mL: 1g, treating the wood fiber powder by adopting an oil bath heating method, stirring and reacting at 50-120 ℃ for 10-90 min, and adding cold water to dilute after the reaction is finished to terminate the reaction; carrying out vacuum separation on the reaction system at room temperature to obtain a solid part and a liquid part, wherein the solid part is cellulose; diluting the liquid part with pure water, centrifuging, precipitating, and separating to obtain lignin with purity of above 90%, and the supernatant is pentose hydrolyzed from hemicellulose.
2. The method for separating wood fiber by organic acid and homologously preparing furfural according to claim 1 is characterized in that: the wood fiber is more than one of straw, bagasse, corncob, wood chip and rice straw.
3. The method for separating wood fiber by organic acid and homologously preparing furfural according to claim 1 is characterized in that: the organic acid is a solution with the mass concentration fraction of 50-85%, and specifically is more than one of maleic acid, formic acid, acetic acid, p-toluenesulfonic acid, oxalic acid and phosphoric acid.
4. The method for separating wood fiber by organic acid and homologously preparing furfural according to claim 1 is characterized in that: the stirring reaction time is 10-90 min.
5. The method for separating wood fiber by organic acid and homologously preparing furfural according to claim 1 is characterized in that: the amount of cold water used for terminating the reaction by adding cold water is 20-40 mL per 2g of the wood fiber powder.
6. The method for separating wood fiber by organic acid and homologously preparing furfural according to claim 1, characterized by comprising the following steps of: the liquid part is diluted by pure water, centrifugally precipitated and separated, and the method specifically comprises the following steps: diluting the liquid part until the mass fraction of the acid is 2-10%, transferring the liquid part into a centrifugal machine, centrifuging the liquid part for 5-15min at 3000-8000 r to obtain a precipitate, namely lignin, and freeze-drying the precipitate for later use; heating the obtained supernatant to 100 ℃, carrying out autocatalysis by using organic acid as a catalyst to prepare furfural, and then carrying out rotary evaporation and concentration on the solution to obtain an organic acid solution for recycling.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111393670A (en) * | 2020-03-26 | 2020-07-10 | 齐鲁工业大学 | Method for efficiently extracting and separating active lignin |
| CN111875568A (en) * | 2020-07-27 | 2020-11-03 | 齐鲁工业大学 | Method for comprehensive utilization of biomass by staged refining |
| CN112552266A (en) * | 2020-12-18 | 2021-03-26 | 安徽工业大学 | Method for preparing furfural by extracting hemicellulose from alkali liquor |
| CN114085252A (en) * | 2021-10-21 | 2022-02-25 | 中国林业科学研究院林产化学工业研究所 | Comprehensive utilization method for separating wood fiber by organic acid catalysis two-phase system |
| CN116374990A (en) * | 2023-03-08 | 2023-07-04 | 华南理工大学 | Method for preparing powder/block biomass grade pore carbon by pretreatment of lignocellulose biomass with formic acid |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111393670A (en) * | 2020-03-26 | 2020-07-10 | 齐鲁工业大学 | Method for efficiently extracting and separating active lignin |
| CN111875568A (en) * | 2020-07-27 | 2020-11-03 | 齐鲁工业大学 | Method for comprehensive utilization of biomass by staged refining |
| CN112552266A (en) * | 2020-12-18 | 2021-03-26 | 安徽工业大学 | Method for preparing furfural by extracting hemicellulose from alkali liquor |
| CN114085252A (en) * | 2021-10-21 | 2022-02-25 | 中国林业科学研究院林产化学工业研究所 | Comprehensive utilization method for separating wood fiber by organic acid catalysis two-phase system |
| CN116374990A (en) * | 2023-03-08 | 2023-07-04 | 华南理工大学 | Method for preparing powder/block biomass grade pore carbon by pretreatment of lignocellulose biomass with formic acid |
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Application publication date: 20200114 |