CN114043589A - Method for applying modified industrial alkali lignin to wood heat treatment - Google Patents
Method for applying modified industrial alkali lignin to wood heat treatment Download PDFInfo
- Publication number
- CN114043589A CN114043589A CN202111456963.9A CN202111456963A CN114043589A CN 114043589 A CN114043589 A CN 114043589A CN 202111456963 A CN202111456963 A CN 202111456963A CN 114043589 A CN114043589 A CN 114043589A
- Authority
- CN
- China
- Prior art keywords
- heat treatment
- wood
- lignin
- deionized water
- industrial alkali
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27K—PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR; CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS
- B27K3/00—Impregnating wood, e.g. impregnation pretreatment, for example puncturing; Wood impregnation aids not directly involved in the impregnation process
- B27K3/52—Impregnating agents containing mixtures of inorganic and organic compounds
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27K—PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR; CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS
- B27K3/00—Impregnating wood, e.g. impregnation pretreatment, for example puncturing; Wood impregnation aids not directly involved in the impregnation process
- B27K3/02—Processes; Apparatus
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Wood Science & Technology (AREA)
- Forests & Forestry (AREA)
- Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Compounds Of Unknown Constitution (AREA)
- Chemical And Physical Treatments For Wood And The Like (AREA)
Abstract
The invention provides a method for applying modified industrial alkali lignin to wood heat treatment. The lignin with smaller molecular weight is obtained by simply carrying out acid treatment on the industrial alkali lignin of the pulping and papermaking waste and cracking the lignin by means of a tetrahydrofuran-water cosolvent under the conditions of acidity and high temperature. The lignin is impregnated into the wood cell wall through negative pressure impregnation, and in the high-temperature saturated steam heat treatment process, the lignin migrates from the cell wall layer with higher concentration to the cell wall layer with lower concentration under the action of a thermodynamic driving force, and the low-molecular-weight lignin modified by the tetrahydrofuran-water cosolvent is more likely to migrate. The mesomechanics property of the cell wall is improved along with the increase of the lignin concentration in the cell wall, and then the macroscopic mechanics property of the heat-treated wood is enhanced.
Description
Technical Field
The invention relates to a method for using modified industrial alkali lignin for wood heat treatment, belonging to the field of wood heat treatment.
Background
The heat treatment technology of wood has been known as an environment-friendly physical modification technology of wood for more than thirty years. The high temperature heat treatment of wood is usually to heat the wood to 160-260 ℃ for several hours in an oxygen-free or oxygen-deficient environment. Heat treatment is a wood modification technology which is successfully applied in industrialization, and heat-treated wood products are widely applied to various products such as building external wall panels, outdoor landscapes, floors, furniture, musical instruments and the like at present. However, the mechanical properties of the wood, in particular the modulus of elasticity (MOE) and the static flexural strength (MOR), decrease after heat treatment. The reduction in mechanical properties greatly limits the range of applications of heat treatment techniques to wood and wood products.
The wall layers of the wood cell wall can be regarded as independent single-layer plates, and the whole cell wall can be regarded as a laminated plate. Where cellulose is considered as reinforcement, lignin and hemicellulose are considered as matrix and the mesomechanical parameters of the two differ little. The extensive degradation of the hemicellulose during the heat treatment process can destroy the stability of the matrix and thus lead to a reduction in mechanical properties. Therefore, the industrial alkali lignin after the modification treatment is impregnated by negative pressure before the heat treatment so as to compensate the degradation of the hemicellulose in the heat treatment. The modified industrial alkali lignin enters each wall layer of the wood cell wall, so that the reduction of the mechanical property of the heat-treated wood can be reduced, and certain scientific significance and economic value are achieved.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a method for modifying industrial alkali lignin for wood heat treatment. The modification method has the advantages of simple and convenient process, low cost and easy control, and can introduce industrial alkali lignin waste generated in the pulping and papermaking industry into the high-temperature heat treatment process of the wood, open up a new way for high-value application of the pulping and papermaking industry, contribute to the protection of the natural environment and the improvement of the utilization rate of biomass resources, and contribute to the promotion of the mechanical property of the heat-treated wood. The technical scheme adopted by the invention is as follows: a method for using modified industrial alkali lignin for wood heat treatment comprises the following specific steps:
(1) 300g of industrial alkali lignin is placed in a 2L beaker, deionized water is added to prepare a 25 wt% solution, and sulfuric acid is slowly added to adjust the pH value under the conditions of water bath heating and magnetic stirring to obtain a coffee solution.
(2) Standing the brown solution for 30min under water bath heating condition, discarding supernatant, washing the precipitate with deionized water to weak acidity, and oven drying the precipitate to obtain brown lignin powder.
(3) Putting brown lignin powder, tetrahydrofuran and deionized water into a hydro-thermal synthesis reaction kettle, and heating at 160 ℃ for 45min to obtain black liquid.
(4) And (3) putting the wood block into black liquid, carrying out normal-temperature negative-pressure impregnation for 3h in a vacuum drying oven, and cleaning the surface of the wood block by using deionized water after the negative-pressure impregnation.
(5) Adding 9mL of deionized water into a hydrothermal synthesis reaction kettle with the inner liner volume of 100mL, putting the wood blocks subjected to negative pressure impregnation into the hydrothermal synthesis reaction kettle, and heating the hydrothermal synthesis reaction kettle through an electrothermal blowing drying oven to carry out heat treatment on the wood blocks.
(6) And after the heat treatment is finished, quickly placing the hydrothermal synthesis reaction kettle in cold water to quickly reduce the temperature.
In step 1, the temperature of the water bath is 70-75 ℃, the concentration of the sulfuric acid is 30-35 wt%, and the pH value of the solution is adjusted to 2.5 by using the sulfuric acid.
In the step 2, when the precipitate is washed by deionized water, the washing is stopped when the pH of the filtrate is 5.5-6.5, and the filter cake is kept to be weakly acidic.
In the step 3, the mass ratio of the lignin, the tetrahydrofuran and the deionized water is 1:10:10, and the heating rate is 10 ℃/min.
In step 4, the vacuum degree in the negative pressure impregnation process is 0.09 MPa.
In step 5, the wood has the size of 70mm x 20mm (axial x radial x chord direction), the heat treatment temperature is 160-200 ℃, and the heat treatment time is 4-6 h.
Compared with the prior art, the invention has the following advantages and effects:
1. after simple acid treatment, the industrial alkali lignin can wash away metal salt mixed in the pulping process. Treating industrial alkali lignin with tetrahydrofuran-water cosolvent under acidic and high temperature conditions to reduce the molecular weight of lignin.
2. Under the action of saturated steam and certain pressure, the lignin with small molecular weight is transferred from the cell wall layer with higher concentration to the cell wall layer with lower concentration under the action of thermodynamic driving force, so that the transfer of the lignin is further promoted and the lignin is uniformly distributed on the cell wall, and the mechanical property of the heat-treated wood is improved.
3. The preparation method has the advantages of simple flow, simple and convenient process, low cost, easy control, good development prospect and further extensive research value.
Detailed Description
The present invention will be described in detail with reference to specific examples below:
example 1
(1) 300g of industrial alkali lignin is placed in a 2L beaker, deionized water is added to prepare a 25 wt% solution, and sulfuric acid is slowly added to adjust the pH value under the conditions of water bath heating and magnetic stirring to obtain a coffee solution.
(2) Standing the brown solution for 30min under water bath heating condition, discarding supernatant, washing the precipitate with deionized water to weak acidity, and oven drying the precipitate to obtain brown lignin powder.
(3) Putting brown lignin powder, tetrahydrofuran and deionized water into a hydro-thermal synthesis reaction kettle, and heating at 160 ℃ for 45min to obtain black liquid.
(4) Putting the spruce wood block into black liquid, carrying out normal-temperature negative-pressure impregnation for 3h in a vacuum drying oven, and cleaning the surface of the wood block by using deionized water after the negative-pressure impregnation.
(5) Adding 9mL of deionized water into a hydrothermal synthesis reaction kettle with the inner liner volume of 100mL, putting the spruce wood block subjected to negative pressure impregnation into the hydrothermal synthesis reaction kettle, and heating the reaction kettle through an electrothermal blowing drying oven to carry out heat treatment on the spruce wood.
(6) And after the heat treatment is finished, quickly placing the hydrothermal synthesis reaction kettle in cold water to quickly reduce the temperature.
In step 1, the temperature of the water bath was 70 ℃ and the sulfuric acid concentration was 30 wt%, and the pH of the solution was adjusted to 2.5 with sulfuric acid.
In step 2, when the precipitate is washed by deionized water, the washing is stopped when the pH of the filtrate is 5.5, and the filter cake is kept weakly acidic.
In the step 3, the mass ratio of the lignin, the tetrahydrofuran and the deionized water is 1:10:10, and the heating rate is 10 ℃/min.
In step 4, the vacuum degree in the negative pressure impregnation process is 0.09 MPa.
In step 5, the spruce wood pieces were 70mm by 20mm (axial by radial by chord), heat treated at 160 ℃ for 4 h.
Example 2
(1) 300g of industrial alkali lignin is placed in a 2L beaker, deionized water is added to prepare a 25 wt% solution, and sulfuric acid is slowly added to adjust the pH value under the conditions of water bath heating and magnetic stirring to obtain a coffee solution.
(2) Standing the brown solution for 30min under water bath heating condition, discarding supernatant, washing the precipitate with deionized water to weak acidity, and oven drying the precipitate to obtain brown lignin powder.
(3) Putting brown lignin powder, tetrahydrofuran and deionized water into a hydro-thermal synthesis reaction kettle, and heating at 160 ℃ for 45min to obtain black liquid.
(4) Putting the spruce wood block into black liquid, carrying out normal-temperature negative-pressure impregnation for 3h in a vacuum drying oven, and cleaning the surface of the wood block by using deionized water after the negative-pressure impregnation.
(5) Adding 9mL of deionized water into a hydrothermal synthesis reaction kettle with the inner liner volume of 100mL, putting the spruce wood block subjected to negative pressure impregnation into the hydrothermal synthesis reaction kettle, and heating the reaction kettle through an electrothermal blowing drying oven to carry out heat treatment on the spruce wood.
(6) And after the heat treatment is finished, quickly placing the hydrothermal synthesis reaction kettle in cold water to quickly reduce the temperature.
In step 1, the bath temperature was 75 ℃ and the sulfuric acid concentration was 35 wt%, and the pH of the solution was adjusted to 2.5 with sulfuric acid.
In step 2, when the precipitate is washed by deionized water, the washing is stopped when the pH of the filtrate is 6.5, and the filter cake is kept weakly acidic.
In the step 3, the mass ratio of the lignin, the tetrahydrofuran and the deionized water is 1:10:10, and the heating rate is 10 ℃/min.
In step 4, the vacuum degree in the negative pressure impregnation process is 0.09 MPa.
In step 5, spruce wood was 70mm by 20mm (axial by radial by chord) in size, heat treated at 180 ℃ for 6 h.
Comparative example 1
(1) Adding 9mL of deionized water into a hydrothermal synthesis reaction kettle with the inner liner volume of 100mL, putting the spruce wood blocks into the hydrothermal synthesis reaction kettle, and heating the hydrothermal synthesis reaction kettle through an electrothermal blowing dry box to carry out heat treatment on the spruce wood blocks.
(2) And after the heat treatment is finished, quickly placing the hydrothermal synthesis reaction kettle in cold water to quickly reduce the temperature.
In step 1, the spruce wood pieces were 70mm by 20mm (axial by radial by chord), heat treated at 160 ℃ for 4 h.
| Bending strength (MPa) | Flexural modulus of elasticity (MPa) | Compressive strength along grain (MPa) | |
| Example 1 | 81.638 | 8578.86 | 47.93 |
| Example 2 | 74.435 | 7517.45 | 37.68 |
| Comparative example 1 | 72.805 | 7046.08 | 36.98 |
TABLE 1 test results Table for example 1, example 2 and comparative example 1 (results are the average of results of twenty experiments)
As can be seen from the above table, the mechanical properties of example 1 are the best; in the embodiment 2, as the heat treatment temperature is increased and the heat treatment time is prolonged, the mechanical properties are reduced compared with those of the embodiment 1; comparative example 1 is the worst of each mechanical property. The heat treatment temperature and time of the example 1 are the same as those of the comparative example 1, but the mechanical properties of the example 1 are obviously higher than those of the comparative example 1, and the method shows that the mechanical properties of the heat-treated wood can be improved to a certain extent by using the industrial alkali lignin after the modification treatment by negative pressure impregnation of the tetrahydrofuran-water cosolvent before the heat treatment.
Claims (6)
1. A method for modifying industrial alkali lignin for heat treatment of wood is characterized by comprising the following steps:
(1) placing 300g of industrial alkali lignin in a 2L beaker, adding deionized water to prepare a 25 wt% solution, and slowly adding sulfuric acid to adjust the pH value under the conditions of water bath heating and magnetic stirring to obtain a coffee solution;
(2) standing the brown solution for 30min under the water bath heating condition, removing supernatant, washing the precipitate with deionized water to weak acidity, and drying the precipitate to obtain brown lignin powder;
(3) putting brown lignin powder, tetrahydrofuran and deionized water into a hydro-thermal synthesis reaction kettle, and heating at 160 ℃ for 45min to obtain black liquid;
(4) putting the wood blocks into the black liquid, placing the wood blocks into a vacuum drying oven for normal-temperature negative-pressure impregnation for 3 hours, and cleaning the surfaces of the wood blocks by using deionized water after the negative-pressure impregnation;
(5) adding 9mL of deionized water into a hydrothermal synthesis reaction kettle with the inner liner volume of 100mL, putting the wood blocks subjected to negative pressure impregnation into the hydrothermal synthesis reaction kettle, and heating the reaction kettle through an electrothermal blowing drying oven to carry out heat treatment on the fir;
(6) and after the heat treatment is finished, quickly placing the hydrothermal synthesis reaction kettle in cold water to quickly reduce the temperature.
2. The method for modifying industrial alkali lignin used for heat treatment of wood according to claim 1, wherein in the step (1), the water bath temperature is 70-75 ℃, the sulfuric acid concentration is 30-35 wt%, and the pH value of the solution is adjusted to 2.5 by using sulfuric acid.
3. The method for using the modified industrial alkali lignin for wood heat treatment according to claim 1, wherein in the step (2), when the precipitate is washed by deionized water, the washing is stopped when the pH of the filtrate is 5.5-6.5, and the filter cake is kept weakly acidic.
4. The method for modifying the industrial alkali lignin for the heat treatment of the wood according to claim 1, wherein in the step (3), the mass ratio of the lignin to the tetrahydrofuran to the deionized water is 1:10:10, and the temperature rise rate is 10 ℃/min.
5. The method for modifying industrial alkali lignin for wood heat treatment according to claim 1, wherein in the step (4), the vacuum degree in the negative pressure impregnation process is 0.09 MPa.
6. The method for heat treatment of wood by using modified lignin according to claim 1, wherein in the step (5), the fir wood has the size of 70mm x 20mm (axial x radial x chord direction), the heat treatment temperature is 160-200 ℃, and the heat treatment time is 4-6 h.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111456963.9A CN114043589A (en) | 2021-12-01 | 2021-12-01 | Method for applying modified industrial alkali lignin to wood heat treatment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111456963.9A CN114043589A (en) | 2021-12-01 | 2021-12-01 | Method for applying modified industrial alkali lignin to wood heat treatment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114043589A true CN114043589A (en) | 2022-02-15 |
Family
ID=80212022
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111456963.9A Pending CN114043589A (en) | 2021-12-01 | 2021-12-01 | Method for applying modified industrial alkali lignin to wood heat treatment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114043589A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102250363A (en) * | 2011-06-07 | 2011-11-23 | 中国林业科学研究院林产化学工业研究所 | Modification method of lignin |
| CN107759241A (en) * | 2017-11-21 | 2018-03-06 | 北京林业大学 | A kind of method of plasticizing phenol formaldehyde base industry alkali lignin wood ceramics |
| CN110421669A (en) * | 2019-07-17 | 2019-11-08 | 北京林业大学 | A kind of method of montmorillonite Composite industrial lignin improved wood |
-
2021
- 2021-12-01 CN CN202111456963.9A patent/CN114043589A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102250363A (en) * | 2011-06-07 | 2011-11-23 | 中国林业科学研究院林产化学工业研究所 | Modification method of lignin |
| CN107759241A (en) * | 2017-11-21 | 2018-03-06 | 北京林业大学 | A kind of method of plasticizing phenol formaldehyde base industry alkali lignin wood ceramics |
| CN110421669A (en) * | 2019-07-17 | 2019-11-08 | 北京林业大学 | A kind of method of montmorillonite Composite industrial lignin improved wood |
Non-Patent Citations (2)
| Title |
|---|
| HAIZHEN ZHOU: "Multiscale Modification of Populus cathayana by Alkali Lignin Combined with Heat Treatment", 《POLYMERS》 * |
| 李忠正: "《禾草类纤维制浆造纸 中文版 第2卷》", 31 March 2013, 中国轻工业出版社 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108582377B (en) | Method for integrating wood compression and in-situ hot treatment under pressure and compressed wood prepared by method | |
| CN113305959B (en) | Method for improving size stability of fast-growing wood by using lignin-based modified liquid medicine | |
| CN106403519A (en) | Wood material drying method | |
| CN106393364A (en) | Paulownia wood softening processing method capable of improving hand feel of paulownia wood | |
| CN108407002B (en) | Phosphatized wood and preparation method thereof | |
| CN113146789A (en) | Preparation method of high-strength formaldehyde-free wood fiberboard, fiberboard and application | |
| CN112720747A (en) | Preparation method of high-strength compact wood | |
| CN113815080B (en) | Thermal-modification deformation-resistant household door plate and production process thereof | |
| WO2022052775A1 (en) | Production process of non-adhesive formaldehyde-free fiber board for straw co-production of fulvic acid | |
| CN106217532A (en) | A kind of Wood heat treatment method | |
| CN114043589A (en) | Method for applying modified industrial alkali lignin to wood heat treatment | |
| CN106426451A (en) | Multifunctional treating method for planted fast-growing forest wood | |
| CN107322751A (en) | A kind of preparation method of modified heat treatment compressed wood | |
| CN108908605B (en) | Drying method of resin-impregnated modified wood | |
| CN108340461A (en) | A kind of novel recombination is wooden to make method | |
| CN105690516B (en) | A kind of hydrophobic timber of entirety and preparation method thereof | |
| CN110181628B (en) | Environment-friendly high-strength heat-treated rubber wood and modification method thereof | |
| CN108515587A (en) | A kind of high-carbon anti-corrosion bamboo wallboard and its production method | |
| CN112063192A (en) | Bamboo composite board preparation technology | |
| CN111823343A (en) | Method for treating rubber wood to improve surface coating performance based on steam explosion method | |
| CN108908594B (en) | Treatment method for prolonging effective time of mildew-proof bamboo wood | |
| CN111251393A (en) | Mildew-proof and corrosion-resistant treating agent for modifying plate | |
| CN111849415A (en) | Environment-friendly waterproof adhesive and preparation method thereof | |
| CN113352418B (en) | Method for enhancing longitudinal mechanical property of wood | |
| CN112207937B (en) | Preparation method of rice hull fireproof plate |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20220215 |
|
| WD01 | Invention patent application deemed withdrawn after publication |