Processing method of biomass material and in-situ liquefaction accelerant

Abstract

The invention provides a processing method of a biomass material and an in-situ liquefaction accelerant, according to the method, in-situ liquefaction reaction is promoted on the surface of the biomass material to be glued to achieve gluing, and the in-situ liquefaction accelerant comprises a liquefying agent and a catalyst, the liquefying agent is selected from one or more of alcohols or phenols, polymers of phenols or alcohols or solutions; the active component of the catalyst is an alkaline or acidic substance. According to the in-situ liquefaction accelerant provided by the invention, a plant liquefaction system is used as a basis, a liquefier is matched with a catalyst to perform surface in-situ liquefaction on biomass materials such as bamboo and wood, in-situ liquefaction is performed on the surface by utilizing high temperature, and a product is subjected to polycondensation again, so that a firm adhesive layer is formed on a bonding interface to connect different bonding interfaces; ideal gluing is achieved, emission of harmful substances in the gluing process is reduced, the gluing technology is simplified, recycling of materials is effectively promoted, and then efficient production and high-value utilization of biomass materials are completed.

Description

Technical Field

[0001] The invention relates to the technical field of composite material processing and manufacturing, and in particular to a biomass material processing method and an in-situ liquefaction promoter. Background Art

[0002] As natural biomass materials, wood and bamboo have the characteristics of rapid growth, high strength, high toughness, good rigidity, easy processing, and short renewal cycle. They are widely used in construction, furniture, transportation and other fields, and play an important role in national economic production. Natural bamboo does not have gluing power, and it needs to be glued to prepare the raw materials into bamboo composite materials. Wood and bamboo adhesives mainly include aldehyde adhesives based on phenolic and urea-formaldehyde systems, natural adhesive systems such as soybean glue and starch glue based on protein, and amino adhesives represented by isocyanates.

[0003] Existing bamboo adhesives include aldehyde adhesives, represented by phenol formaldehyde and urea formaldehyde. In the synthesis of phenol formaldehyde and urea formaldehyde, toxic formaldehyde is used to perform addition and condensation reactions on phenol and urea. In the case of incomplete formaldehyde reaction, excess formaldehyde will be released into the environment. This release exists in the synthesis and use of adhesives, causing great harm to the environment and users. The synthesis of aldehyde resins requires continuous regulation of the process parameters of the solvent system to ensure the performance of the adhesive, which increases the difficulty of its synthesis. The synthesis of natural adhesives represented by soy protein glue requires the addition of natural additives. Although the release of harmless substances into the environment is avoided, there are defects such as poor water resistance of protein glue, fragile adhesive system, complex synthesis process and high synthesis cost. In addition, polyvinyl acetate used in bamboo composite materials also has defects such as poor water resistance. Amino resins represented by isocyanates have advantages such as good water resistance and high strength, but the high price and complex synthesis process limit their use in bamboo gluing.

[0004] Existing bamboo adhesives also have the problem of needing to use chemical raw materials for synthesis before gluing, which greatly reduces the gluing efficiency and increases the gluing cost. The synthesis requires high technical difficulty and is prone to produce environmentally harmful substances.

[0005] Therefore, an improved solution needs to be developed to meet the processing requirements of biomass materials. Summary of the invention

[0006] The first purpose of the present invention is to design a new biomass material processing method by combining the natural characteristics of biomass materials such as bamboo and wood. The method innovatively proposes a path to achieve gluing by promoting an in-situ liquefaction reaction on the surface of the biomass material to be glued. The method is simple, environmentally friendly and low-cost, and can be ideally used for gluing biomass materials such as bamboo and wood.

[0007] Specifically, the processing method provided by the present invention is to coat the in-situ liquefaction promoter on the first surface to be bonded and / or the second surface to be bonded of the biomass material, and bond the first surface to be bonded and the second surface to be bonded by cold pressing, heat curing or hot pressing.

[0008] In the processing method provided by the present invention, the in-situ liquefaction promoter comprises a liquefier, and the liquefier is selected from one or more of alcohols or phenols, polymers of phenols or alcohols, or solutions thereof.

[0009] That is, the liquefier may be alcohols or phenols themselves, or a polymer of alcohols or phenols, or a solution of alcohols or phenols, or a solution of alcohols or phenols polymers.

[0010] When the liquefier is a solution of alcohols, phenols or polymers thereof, the solvent of the solution is selected from alcohols or phenols having hydroxyl groups, preferably water, methanol or ethanol, which has a better solvent effect on the liquefier and catalyst and is conducive to promoting in-situ bonding.

[0011] In some embodiments provided by the present invention, the liquefier is selected from one or more of glycerol, pentaerythritol, polyethylene glycol (400-600), 1,2-propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, trimethylolpropane, phenol or their solutions.

[0012] In some preferred embodiments provided by the present invention, the liquefier is a polyol, a polymer thereof or an aqueous solution thereof, preferably glycerol or polyethylene glycol (PEG400-PEG1000) or an aqueous solution thereof.

[0013] When the liquefier of the present invention is provided in the form of a solution, the appropriate mass concentration is 30-100%, preferably 40-50%.

[0014] More preferably, the liquefier is an aqueous solution of glycerol or polyethylene glycol with a mass concentration of 30 to 100%.

[0015] In the processing method provided by the present invention, the in-situ liquefaction promoter includes a catalyst in addition to a liquefier, and the active component of the catalyst is an acidic or alkaline substance that can stimulate the surface activity of bamboo wood.

[0016] The catalyst of the present invention can be either directly an acidic or alkaline substance (i.e., the active component itself) or a solution of an acidic or alkaline substance (particularly preferred).

[0017] When the catalyst of the present invention is provided in the form of a solution, the solvent of the solution is preferably water, which has a better solvent effect on the catalyst and is conducive to promoting in-situ bonding.

[0018] In the catalyst of the present invention, the alkaline substance may be a strong base or a strong base salt, wherein the strong base includes one or more of sodium hydroxide, potassium hydroxide or magnesium hydroxide; the strong base salt includes one or more of sodium carbonate, sodium bicarbonate or potassium carbonate. The acidic substance may be a strong acid or a weak acid, wherein the strong acid includes one or more of hydrochloric acid, sulfuric acid, nitric acid, perchloric acid, selenic acid, hydrobromic acid, hydroiodic acid and chloric acid, and the weak acid includes one or two of phosphoric acid and acetic acid.

[0019] Preferably, the catalyst is sodium hydroxide, sodium carbonate, phosphoric acid or a solution thereof, and an aqueous solution of sodium hydroxide, sodium carbonate or phosphoric acid having a mass concentration of 0% to 60% is particularly preferred, and a mass concentration of 10% to 50% is preferred, and a particularly suitable concentration is 10%, 20% or 50%, etc. The use of the above catalysts can reduce the reaction temperature and increase the reaction rate.

[0020] The main chemical components of biomass materials such as bamboo and wood are composed of cellulose, hemicellulose and lignin. According to the supramolecular structure of bamboo cells, lignin wraps around the outside of bamboo cellulose and hemicellulose to form a hard shell. Lignin is a biopolymer with a three-dimensional network structure formed by three phenylpropane units connected to each other through ether bonds, containing rich active groups such as aromatic ring structures, aliphatic and aromatic hydroxyls and quinone groups. Among them, the β-O-4 bond (ether bond) connecting the lignin monomers is the most easily broken part of lignin. Based on the above characteristics of biomass materials, in the present invention, lignin is liquefied using a liquefier such as glycerol to break the β-O-4 bond (ether bond) connecting the lignin. Under the action of temperature, the lignin re-condenses to form a solid solid under the C=C connection, and the bonding interface part is connected to form bonding force. In addition, catalysts such as sodium hydroxide have the ability to destroy the lignin-carbohydrate complex (LCC) in the supramolecular structure of biomass materials, so that the lignin is exposed more completely and can fully participate in the reaction to form bonding force.

[0021] In the processing method provided by the present invention, the mass ratio of the liquefier to the catalyst (when the liquefier and the catalyst are provided in the form of a solution, the amounts here are calculated only on the basis of the solute, the same below) is 2:0.5-2, preferably 2:1.

[0022] The processing method provided by the present invention specifically includes coating the in-situ liquefaction promoter on the first surface to be glued and / or the second surface to be glued of the biomass material, and gluing the first surface to be glued and the second surface to be glued by hot pressing or cold pressing and heat curing.

[0023] Preferably, the first surface to be glued and the second surface to be glued are both flat and in contact with each other. To facilitate cold pressing and hot curing, the biomass materials on which the first surface to be glued and the second surface to be glued are both in plate shape with a thickness ranging from 0.5 to 2 cm, preferably 1 to 2 cm.

[0024] The thickness of the biomass material where the first surface to be glued and the second surface to be glued are located can be the same or different, and the specific biomass materials can also be the same or different, preferably the same, to achieve a better gluing effect.

[0025] The hot pressing or cold pressing heat curing can be achieved by using various known equipment / techniques, preferably in an oven or a hot press.

[0026] Preferably, the cold pressing heat curing comprises: using an oven to heat the biomass material to be bonded coated with the adhesive from room temperature to 150-160° C. at 1-2.5 MPa, maintaining for 20-80 minutes; then keeping the pressure down to room temperature (maintaining the pressure throughout the heating and cooling process).

[0027] More preferably, the cold-pressing heat curing comprises: using an oven to raise the temperature of the biomass material to be bonded coated with the adhesive from room temperature to 160° C. at 1.5 MPa, and maintaining the temperature for 80 minutes.

[0028] Preferably, the hot pressing comprises: using a hot press to heat the biomass material to be bonded coated with the in-situ liquefaction promoter to 120-180°C (preferably 150-160°C) at 0.5-2.5 MPa (preferably 1-2.5 MPa), maintaining for 20-80 minutes (preferably 40-80 minutes); then cooling to room temperature while maintaining the pressure.

[0029] More preferably, the hot pressing comprises: using a hot press to raise the temperature of the biomass material to be bonded coated with the adhesive from room temperature to 160° C. at 1.5 MPa, and maintaining the temperature for 80 minutes.

[0030] In some embodiments provided by the present invention, the hot pressing comprises: using a hot press to heat the biomass material to be bonded coated with the adhesive from room temperature to 120-150°C (also referred to as the first temperature, excluding 150°C) at 1-2.5MPa; maintaining for 5-10 minutes, and then continuously raising the temperature to 150-160°C (also referred to as the second temperature), maintaining for 20-80 minutes; and then maintaining the pressure to room temperature (maintaining the pressure throughout the heating and cooling process). The method provided by the present invention is to maintain the temperature for 5-10 minutes after the temperature is raised to the first temperature (120-150°C). Under the action of high temperature, the liquefier with a catalyst can liquefy the lignin at the bonding interface of biomass materials such as bamboo and wood. The main mechanism of action is to break the β-O-4 bond (ether bond) connecting the lignin, so that the lignin network structure forms a small molecule melting system, and forms a flowable liquid at the interface. After liquefaction, the liquid at the interface penetrates into the gaps on the interface of biomass materials such as bamboo and wood under pressure. When the temperature reaches 150-160°C, maintain it for 20-80 minutes to allow the liquefied products on the interface to gradually polymerize under the action of high temperature. The main mechanism of action is that the liquefied lignin monomers are easily repolymerized through C=C bonds under the action of temperature. After the polymerization is completed, a solid interface layer is formed on the interface, which forms a cross-linked interlocking structure with the liquefied products that penetrate into the gaps of biomass materials such as bamboo and wood, thereby forming an interface bonding force. After maintaining it for 20-80 minutes, continue to maintain the pressure at 1-2.5MPa, cool the hot press to room temperature and remove the biomass material.

[0031] In the above process, the bonding interface of biomass materials such as bamboo and wood is liquefied and then polymerized in situ to form bonding force. The biomass materials to be bonded after the coating is completed (the first bonding surface to be bonded and the second bonding surface to be bonded coated with the adhesive are tightly attached together) are hot pressed using a hot press to complete the bonding.

[0032] In the processing method provided by the present invention, the amount of the in-situ liquefaction promoter on the surface of the biomass material is 24-48 g / m 2 Preferably, 30-40 g / m 2 .

[0033] In the processing method provided by the present invention, the biomass material includes a biomass material having lignin and / or hemicellulose; preferably, the biomass material includes a natural material and a processed material, wherein the natural material is selected from one or more of bamboo, wood, straw or reed stalks; and may be an unprocessed original state, a block material, a powder material, etc. The processed material includes a board (such as plywood, veneer laminate, particle board, fiberboard or blockboard, etc.), a film material, a powder material, etc. made of the above natural materials.

[0034] Preferably, the wood includes softwood and hardwood.

[0035] More preferably, the biomass material is bamboo or wood, especially bamboo and poplar, which are particularly suitable for the processing method of the present invention.

[0036] The second object of the present invention is to provide an in-situ liquefaction accelerator, which includes a liquefier, and the liquefier is selected from one or more of alcohols or phenols, polymers or solutions of phenols or alcohols.

[0037] That is, the liquefier may be alcohols or phenols themselves, or a polymer of alcohols or phenols, or a solution of alcohols or phenols, or a solution of alcohols or phenols polymers.

[0038] When the liquefier is a solution of alcohols, phenols or polymers thereof, the solvent of the solution is selected from alcohols or phenols having hydroxyl groups, preferably water, methanol or ethanol, which has a better solvent effect on the liquefier and catalyst and is conducive to promoting in-situ bonding.

[0039] In some embodiments provided by the present invention, the liquefier is selected from one or more of glycerol, pentaerythritol, polyethylene glycol (400-600), 1,2-propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, trimethylolpropane, phenol or their solutions.

[0040] In some preferred embodiments provided by the present invention, the liquefier is a polyol, a polymer thereof or an aqueous solution thereof, preferably glycerol or polyethylene glycol (PEG400-PEG1000) or an aqueous solution thereof.

[0041] When the liquefier of the present invention is provided in the form of a solution, the appropriate mass concentration is 30-100%, preferably 40-50%.

[0042] More preferably, the liquefier is an aqueous solution of glycerol or polyethylene glycol with a mass concentration of 30 to 100%.

[0043] The in-situ liquefaction accelerator provided by the present invention includes a catalyst in addition to a liquefaction agent. The active component of the catalyst is an acidic or alkaline substance that can stimulate the surface activity of bamboo wood.

[0044] The catalyst of the present invention can be either directly an acidic or alkaline substance (i.e., the active component itself) or a solution of an acidic or alkaline substance (particularly preferred).

[0045] When the catalyst of the present invention is provided in the form of a solution, the solvent of the solution is preferably water, which has a better solvent effect on the catalyst and is conducive to promoting in-situ bonding.

[0046] In the catalyst of the present invention, the alkaline substance may be a strong base or a strong base salt, wherein the strong base includes one or more of sodium hydroxide, potassium hydroxide or magnesium hydroxide; the strong base salt includes one or more of sodium carbonate, sodium bicarbonate or potassium carbonate. The acidic substance may be a strong acid or a weak acid, wherein the strong acid includes one or more of hydrochloric acid, sulfuric acid, nitric acid, perchloric acid, selenic acid, hydrobromic acid, hydroiodic acid and chloric acid, and the weak acid includes one or two of phosphoric acid and acetic acid.

[0047] Preferably, the catalyst is sodium hydroxide, sodium carbonate, phosphoric acid or a solution thereof, and an aqueous solution of sodium hydroxide, sodium carbonate or phosphoric acid having a mass concentration of 0% to 60% is particularly preferred, and a mass concentration of 10% to 50% is preferred, and a particularly suitable concentration is 10%, 20% or 50%, etc. The use of the above catalysts can reduce the reaction temperature and increase the reaction rate.

[0048] The in-situ liquefaction accelerator provided by the present invention has a mass dosage ratio of the liquefier to the catalyst (when the liquefier and the catalyst are provided in the form of a solution, the dosages herein are calculated only on the basis of the solute) of 2:0.5-2, preferably 2:1.

[0049] As a preferred embodiment of the present invention, the in-situ liquefaction accelerator is made of glycerol, sodium hydroxide and water in a mass ratio of 2:1:0.5.

[0050] The in-situ liquefaction accelerator provided by the present invention can be used to first fully mix the liquefier and the catalyst to form an adhesive, and then evenly apply it on the surface to be bonded to achieve bonding; the liquefier and the catalyst can also be applied separately, that is, first apply the catalyst solution on the surface to be bonded, and then further apply the liquefier on the surface, so that the two solutions can completely cover the surface to be bonded.

[0051] The in-situ liquefaction accelerator provided by the present invention has the advantages of being green, environmentally friendly, formaldehyde-free, low-cost, mild, and biodegradable. It can achieve bonding at different hot pressing temperatures, and can achieve a maximum dry bonding strength of 10.69 MPa and a wet shear strength of 5.21 MPa, which are close to phenolic resins. At the same time, the adhesive system has a simple construction process, is environmentally friendly, and has low cost.

[0052] The present invention uses a liquefaction agent in combination with a catalyst to carry out in-situ liquefaction of the surface of biomass materials such as bamboo and wood, and uses high temperature to re-condense the surface in-situ liquefaction product, thereby forming a solid adhesive layer at the bonding interface, achieving ideal bonding, not only reducing the emission of harmful substances in the bonding process, but also simplifying the bonding process, effectively promoting the recycling and reuse of materials, thereby completing the efficient production and high-value utilization of biomass materials, and achieving at least the following specific beneficial effects: (1) Based on the natural chemical characteristics of biomass materials such as wood and bamboo, in-situ liquefaction and subsequent polymerization are achieved, which reduces the gluing process and reduces the gluing cost and technical requirements of biomass materials; (2) Using safe, environmentally friendly and mild in-situ liquefaction accelerator, environmentally friendly, mild and degradable bonding is achieved; (3) Non-adhesive direct bonding is achieved, and the adhesive system is used instead of traditional adhesives, which reduces the bonding technology requirements and processing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0054] Figure 1 It is the liquefaction failure rate of glued wood materials affected by in-situ liquefaction accelerators at different temperatures.

[0055] Figure 2 This is a schematic diagram of the effect of bamboo glued using in-situ liquefaction accelerator.

[0056] Figure 3 It is a comparison chart of the bonding strength of in-situ liquefaction accelerators using different catalysts. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] Combine the following Figure 1-Figure 3 Describe the technical solution of the present invention.

[0059] In the following examples, when the liquefier and the catalyst are provided in the form of a solution, the amounts used are calculated only on the basis of the solute.

[0060] Example 1

[0061] This embodiment provides a method for processing biomass materials, which specifically includes: (1) preparing an in-situ liquefaction accelerator, which is composed of glycerol, sodium hydroxide and water in a mass ratio of 2:1:0.5. During the preparation, the glycerol, sodium hydroxide and water are fully stirred and mixed.

[0062] (2) 36 g / m 2 The in-situ liquefaction accelerator is evenly coated on the surface of the bamboo and the bamboo is double-layered. The assembled bamboo is hot-pressed in a hot press at 120-180°C and a pressure of 0.5-2.5MPa for 40-80 minutes (see Table 1 for details). The bamboo pieces are then cooled to room temperature while maintaining the pressure, and the bamboo samples are taken out to complete the gluing.

[0063] The bonding strength of the in-situ liquefaction accelerator prepared in this embodiment on the material is shown in Table 1, and the wood breakage rate is shown in Table 1. Figure 1 The bonding strength test is carried out in accordance with GB 17657-2021 (plywood bonding strength test), and the following examples all refer to this standard.

[0064] Table 1 Bonding strength of in-situ glued bamboo under different hot pressing processes

[0065] Example 2

[0066] This embodiment provides a method for processing biomass materials, which uses different heating stages to control in-situ liquefaction and bonding to achieve in-situ liquefaction and bonding, specifically including: (1) preparing an in-situ liquefaction accelerator, which is composed of glycerol, sodium hydroxide and water in a mass ratio of 2:1:0.5. During the preparation, the glycerol, sodium hydroxide and water are fully stirred and mixed.

[0067] (2) Then at 36 g / m 2 The amount of glue is to evenly apply the in-situ liquefaction accelerator on the surface of the bamboo and perform double-layer bamboo assembly. First, use a hot press to raise the temperature to 120°C and hold it for a certain period of time, then raise the temperature to 160°C and hold it for a certain period of time, then cool the bamboo pieces to room temperature while holding the pressure, and take out the bamboo sample to complete the gluing.

[0068] The bonding strength of the in-situ liquefaction accelerator prepared in this embodiment to the material is shown in Table 2.

[0069] Table 2 Bonding strength of in-situ bonded bamboo at different bonding temperatures

[0070] Example 3

[0071] This Example 3 provides 8 different in-situ liquefaction accelerators, and their specific formulas are shown in Table 3.

[0072] This embodiment also provides a method for processing biomass materials, which specifically includes: The liquefier and catalyst were mixed thoroughly and then 2The glue load is evenly coated on the bamboo surface and the bamboo double-layer blank is assembled. First, the temperature is raised to 120°C and maintained for a certain time, then the temperature is raised to 160°C and maintained for a certain time, and then the bamboo pieces are cooled to room temperature under pressure, and the bamboo samples are taken out to complete the gluing.

[0073] The bonding strength of the bamboo material obtained by in-situ liquefaction bonding in this embodiment is shown in Table 3.

[0074] Table 3 Proportion and bonding strength of in-situ liquefaction accelerators containing different catalysts

[0075] Note: In No. 8, the in-situ liquefaction accelerator is made of glycerol, sodium hydroxide and water in a mass ratio of 2:1:0.5.

[0076] Example 4

[0077] This embodiment provides an in-situ liquefaction accelerator suitable for poplar wood, which is composed of glycerol, sodium hydroxide and water in a mass ratio of 2:1:0.5. The liquefaction solvent and the catalyst are fully stirred and mixed, and then 36 g / m 2 The glue loading is evenly coated on the surface of the poplar wood and the bamboo double-layer assembly is performed. The assembled poplar wood is hot pressed in a hot press at 120-180°C and at a pressure of 0.5-1.5 MPa for 80 minutes, and then the poplar wood is cooled to room temperature while maintaining the pressure, and the poplar wood sample is taken out to complete the gluing. The bonding strength of the poplar wood in-situ liquefaction gluing obtained in this embodiment is shown in Table 4.

[0078] Table 4 In-situ liquefaction bonding strength of poplar wood at different hot pressing temperatures

[0079] Example 5

[0080] This embodiment provides an example of in-situ gluing bamboo with the in-situ liquefaction accelerator prepared in the embodiment, and the specific method is as follows: first, a 50% sodium hydroxide aqueous solution is applied to the surface of the bamboo, and then an 86% glycerol aqueous solution (the amount of glycerol: sodium hydroxide is 2:1) is applied to the surface of the bamboo. The bamboo surface is double-layered.

[0081] The assembled bamboo is hot pressed in a hot press at 160°C for 80 minutes at a pressure of 1.5 MPa, and then the bamboo pieces are cooled to room temperature while being pressed, and the bamboo samples are taken out to complete the gluing. Figure 2 .

[0082] Example 6

[0083] This embodiment provides a method of using PEG400 as a liquefier and a 50% phosphoric acid aqueous solution as a catalyst, wherein the ratio of the liquefier to the catalyst is 1:1, and the liquefied solvent and the catalyst are fully stirred and mixed, and then 36 g / m 2 The glue load is evenly coated on the bamboo surface and the bamboo is double-layered. The assembled bamboo is hot-pressed at 160°C and 1.5MPa for 80 minutes, then the bamboo pieces are cooled to room temperature while being pressed, and the bamboo samples are taken out to complete the gluing. The average gluing strength of the bamboo obtained using this example is 3.06MPa.

[0084] Example 7

[0085] This embodiment provides PEG400 as a liquefier, 5% NaOH aqueous solution as a catalyst, and the ratio of the liquefier to the catalyst is 1:1. The liquefied solvent and the catalyst are fully stirred and mixed, and then 36 g / m 2 The glue loading is evenly coated on the bamboo surface and the bamboo is double-layered. The assembled bamboo is hot-pressed at 120-180°C for 80 minutes at a pressure of 0.5-1.5 MPa, and then the bamboo pieces are cooled to room temperature while being pressed, and the bamboo samples are taken out to complete the gluing. The average gluing strength of the bamboo obtained using this example is 2.18 MPa.

[0086] Test Example 1 Cold Press Heat Curing Bonding

[0087] After coating the in-situ liquefaction accelerator (prepared in Example 1), 0.8 cm wide bamboo strips (thickness 0.2 mm) were tightened using only a pressure clamp and cold pressed and heat cured in an oven at 160°C for 80 minutes. Excellent bamboo strip bonding performance was also obtained, with a bonding strength of up to 3.06 MPa.

[0088] Test Example 2 Bonding Strength

[0089] The adhesive prepared in Example 1 is compared with ordinary commercial adhesives. Under the same test conditions, the strength is close to that of phenolic resin (PF), higher than chitin adhesive (ISLA\ABIC), and higher than isocyanate (EPI) and liquefied product adhesive (LMUF). For details, see the comparison chart. Figure 3 .

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for processing biomass materials, characterized in that: The bonding is achieved by promoting an in-situ liquefaction reaction on the surface of the biomass material to be bonded.

2. The processing method according to claim 1, characterized in that: The in-situ liquefaction promoter is coated on the first surface to be glued and / or the second surface to be glued of the biomass material, and the first surface to be glued and the second surface to be glued are glued by cold pressing, heat curing or hot pressing.

3. The processing method according to claim 1 or 2, characterized in that: The in-situ liquefaction promoter includes a liquefier, and the liquefier is selected from one or more of alcohols or phenols, polymers or solutions of phenols or alcohols; preferably, the liquefier is selected from one or more of glycerol, pentaerythritol, polyethylene glycol (400-600), 1,2-propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, trimethylolpropane, phenol or their solutions; more preferably, the liquefier is glycerol, polyethylene glycol or their aqueous solution.

4. The processing method according to claim 3, characterized in that: The in-situ liquefaction promoter also includes a catalyst, and the active component of the catalyst is an alkaline or acidic substance; preferably, the alkaline substance is an alkali or an alkali salt, and the strong alkali includes one or more of sodium hydroxide, potassium hydroxide or magnesium hydroxide; the alkali salt includes one or more of sodium carbonate, sodium bicarbonate or potassium carbonate; the acidic substance is a strong acid or a weak acid, and the strong acid includes one or more of hydrochloric acid, sulfuric acid, nitric acid, perchloric acid, selenic acid, hydrobromic acid, hydroiodic acid, and chloric acid, and the weak acid includes one or two of phosphoric acid and acetic acid; More preferably, the catalyst is a solution of an acidic or basic substance, especially an aqueous solution.

5. The processing method according to claim 4, characterized in that: In the in-situ liquefaction accelerator, the mass ratio of the liquefier to the catalyst is 2:0.5-2, preferably 2:

1.

6. The processing method according to any one of claims 1 to 5, characterized in that: The hot pressing comprises: using a hot press to heat the biomass material to be bonded coated with the in-situ liquefaction promoter to 120-180° C. at 0.5-2.5 MPa, maintaining the temperature for 20-80 minutes; and then cooling to room temperature while maintaining the pressure; Preferably, a hot press is used to heat the biomass material to be bonded coated with the adhesive from room temperature to 120-150° C. at 1-2.5 MPa; maintained for 5-10 minutes, then continuously heated to 150-160° C., maintained for 20-80 minutes; and then the pressure is maintained to drop to room temperature; The cold-pressing heat curing comprises: using a hot oven to heat the biomass material to be bonded coated with the adhesive from room temperature to 150-160° C. in a fixture or at 1-2.5 MPa, and maintaining the temperature for 20-80 minutes; and then keeping the pressure down to room temperature.

7. The processing method according to claim 6, characterized in that: The amount of the in-situ liquefaction promoter on the surface of the biomass material is 24-48 g / m 2 .

8. The processing method according to any one of claims 1 to 7, characterized in that: The biomass material is a biomass material having lignin, cellulose and hemicellulose; Preferably, the biomass material includes natural materials and processed materials, the natural materials are selected from one or more of bamboo, wood, straw or reed stalks; the processed materials include plates, film materials or powder materials made from the above natural materials.

9. An in-situ liquefaction accelerator, characterized in that: The invention comprises a liquefier, wherein the liquefier is selected from one or more of alcohols or phenols, polymers or solutions of phenols or alcohols; preferably, the liquefier is selected from one or more of glycerol, pentaerythritol, polyethylene glycol, 1,2-propylene glycol, 1,4-butylene glycol, 1,6-hexanediol, neopentyl glycol, trimethylolpropane, phenol or solutions thereof; more preferably, the liquefier is glycerol, polyethylene glycol or an aqueous solution thereof.

10. The in-situ liquefaction accelerator according to claim 9, characterized in that: It also includes a catalyst, the active component of which is an alkaline or acidic substance; preferably, in the in-situ liquefaction promoter, the mass ratio of the liquefier to the catalyst is 2:0.5-2, preferably 2:1.

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