A method for removing the odor of salt bush wood

Abstract

The present application belongs to the technical field of wood processing, and particularly relates to a method for removing the odor of salt-resistant sub-tree wood, which comprises the following steps: configuring a hydrogen peroxide impregnation solution, wherein the hydrogen peroxide impregnation solution comprises a hydrogen peroxide solution with a volume concentration of 5% to 12%, a surfactant and water; impregnating the salt-resistant sub-tree wood in the hydrogen peroxide impregnation solution for 2 to 3 days; taking out the salt-resistant sub-tree wood after a preset impregnation time, washing it with clean water and soaking it for 1 to 2 days; and placing the salt-resistant sub-tree wood after water washing and soaking in the atmosphere to make it reach an air-dried state. The method can remove the odor of the salt-resistant sub-tree wood without changing the original gloss of the wood, effectively solves the problem that the salt-resistant sub-tree wood is difficult to use, and expands the source channel of the wood.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wood processing, and particularly relates to a method for removing the odor of salt-resistant broussonetia papyrifera wood. BACKGROUND

[0002] Wood itself can release unique volatile organic compounds, thereby forming its unique odor. Volatile organic compounds (VOCs) produced by wood are a class of organic compounds with various types and complex components, which are distinguished by different organizations and have various definitions. The more accepted definition of VOCs is that of the World Health Organization (WHO), which defines volatile organic compounds as a class of compounds with a boiling point of 50-260 DEG C and a saturated vapor pressure of more than 133.322 Pa at room temperature, which exist in the air in a vapor state at room temperature. Some of the VOCs released by wood are formed during the growth of wood, and some are newly generated through a series of chemical reactions of the internal components of wood. In general, these VOCs may be derived from volatile organic compounds, tannins, resins, gums or resin, gum secretions formed by fungi invading the trunk, and products generated by the metabolism or degradation of starch, other carbohydrates in wood by microorganisms. Wood odor can affect people's mood, cognition and physical health. Some wood can produce aromatic odor. For example, Dalbergia cochinchinensis can emit a rich fruity aroma, and the aroma of freshly cut surface is more obvious, with a long-lasting and mellow aroma that is not obtrusive. Dalbergia odorifera has a faint aroma, a faint aroma, etc. However, some tropical woods often have a foul and unpleasant odor, such as adenocarcinoma beans, hair medicine trees and some broussonetia papyrifera from Africa. There are more than 40 species of broussonetia papyrifera, and we found that some broussonetia papyrifera from Africa have a foul odor, such as salt-resistant broussonetia papyrifera. Salt-resistant broussonetia papyrifera is mainly distributed in West and Central Africa, and is a famous tropical wood. Its wood is resistant to corrosion and ants, has strong luster, straight to slightly interlocking texture, fine and uniform structure, high weight, high strength and hardness, good processing performance, and is suitable for high-grade furniture, veneer, wooden stairs, cabinets, floors, joinery, vehicles, shipbuilding, etc. It is an excellent substitute for Dalbergia odorifera. However, the freshly cut wood of salt-resistant broussonetia papyrifera has a foul odor, which is often difficult for people to tolerate during processing, and even causes allergic reactions, which limits its widespread use. This wood has a foul odor, but its mechanical properties are excellent, and it is suitable for places that require durability and high strength. If it is widely used, it can alleviate the great pressure on China's forest resources and help solve the problem of lack of large-diameter forest resources in China.

[0003] At present, the causes of the odor generation of the salt-resistant branch wood and the removal method are not studied, so that the salt-resistant branch wood is accumulated and cannot be widely used. Therefore, an odor removal method of the salt-resistant branch wood is urgently needed to provide a prerequisite for the wide use of the salt-resistant branch wood. SUMMARY

[0004] The present application aims to overcome the deficiencies in the prior art, and provide a method for removing the odor of salt-resistant branch wood, which can effectively remove the odor of salt-resistant branch wood and make it widely used.

[0005] To solve the above technical problems, the present application adopts the following technical solutions:

[0006] Step one, configure hydrogen peroxide impregnation solution for standby; wherein: the hydrogen peroxide impregnation solution comprises the following components: 5% to 12% hydrogen peroxide solution, coconut oil acid monoethanol amide sulfosuccinic acid monoester disodium (DMSS) and water;

[0007] Step two, immerse the salt-resistant branch wood in the hydrogen peroxide impregnation solution for oxidizing mercaptans and 6-methylindole and 7-methylindole in the cells of the salt-resistant branch wood;

[0008] Step three, take out the salt-resistant branch wood with the preset impregnation time, rinse with clean water and soak in clean water;

[0009] Step four, take out the salt-resistant branch wood after the preset soaking time and place it in the atmosphere to reach the air-dried state.

[0010] Further, the 5% to 12% hydrogen peroxide solution is prepared according to the proportion of 30% hydrogen peroxide solution 5ml to 12.5 to 25ml water.

[0011] Further, the volume ratio of the 5% to 12% hydrogen peroxide solution, the surfactant and the water is (3 to 4):(1 to 2):(6 to 4).

[0012] Further, the preset impregnation time is 2 to 4 days.

[0013] Further, the preset soaking time is 1 to 2 days.

[0014] Further, the temperature of the hydrogen peroxide impregnation solution is 25 to 40℃.

[0015] The method for identifying the components of volatile organic compounds in salt-resistant branch wood includes the following steps:

[0016] Step one, scrape off the surface layer of the salt-resistant branch wood with a knife, and grind the internal wood into 40 to 60 mesh wood powder;

[0017] Step two, the wood powder obtained in step one is detected by solid phase microextraction gas chromatography-mass spectrometry.

[0018] The on-machine conditions are as follows: split injection; injector temperature: 250 DEG C; carrier gas: high-purity helium; column flow: 0.5 mL / min; programmed temperature: initial temperature 90 DEG C, holding for 1 min, increasing to 280 DEG C at a rate of 10 DEG C / min, holding for 15 min; linear velocity control mode, linear velocity: 35 cm / s; interface temperature: 250 DEG C; electron impact ion (EI) source, electron impact energy 70 eV; ion source temperature: 230 DEG C; mass scan range: mass-to-charge ratio (m / z)=50-500; solvent delay time: 2.5 min.

[0019] The detection results show that the volatile substances in the wood powder include the following relatively pleasant odor volatile substances: 2-ethylhexanol, octanal, alpha-cedrene, 2,4-di-tert-butylphenol, ethyl palmitate and ethyl isocholic acid; and the following unpleasant odor volatile substances: tertiary hexadecyl mercaptan, 6-methyl indole and 7-methyl indole; since the main sources of the odor are determined, the deodorization can be performed in a targeted manner. The mercaptan is a kind of non-aromatic compound containing sulfhydryl functional group (-SH) and is easy to be oxidized; the hydrogen peroxide can oxidize the mercaptan into sulfinate or sulfonic acid salt, so that the odor is basically eliminated after the treatment; the indole is a compound of pyrrole and benzene, and the indole has a strong fecal odor when it is concentrated, has a strong and long-lasting diffusion force, and has a fragrance when it is highly diluted and can be used as a spice. The indole can undergo dimerization and trimerization under the action of strong acid, so that the odor of the indole is removed; however, the strong acid is corrosive and can corrode the wood, thereby reducing the utilization rate of the wood, for example, hydrochloric acid; the indole can also be oxidized into 2,3-dihydroxyindole under the action of hydrogen peroxide, and then oxidized into N-(2-formylphenyl) formamide.

[0020] The 5-12% dilute hydrogen peroxide used in the application can oxidize the mercaptan into unstable disulfide, and the hydrogen peroxide is excessive during the treatment, so that the unstable disulfide is continuously oxidized into sulfonic acid and sulfinate, thereby removing the mercaptan. Meanwhile, the hydrogen peroxide can oxidize the indole into 2,3-dihydroxyindole, and then into N-(2-formylphenyl) formamide. Finally, the indole is oxidized into formanilide, thereby removing the indole.

[0021] The surfactant used in the application helps the hydrogen peroxide in the hydrogen peroxide impregnating solution to penetrate into the cells of the wood and fully react with the mercaptan and indole in the cells, thereby enhancing the deodorization effect.

[0022] In summary, the working principle of the hydrogen peroxide impregnation solution is to utilize the penetration and dispersion effect of surfactants to assist the hydrogen peroxide in the impregnation solution to penetrate into the cell walls of salt-resistant tamarisk wood, oxidizing the thiols and indoles in the contents, thereby achieving the technical effect of removing the odor of salt-resistant tamarisk wood.

[0023] Beneficial effects

[0024] The deodorization treatment method for salt-resistant pine wood provided in the above technical solution can remove volatile substances that produce odor inside the salt-resistant pine wood.

[0025] This method utilizes the permeability and dispersibility of surfactants to assist hydrogen peroxide in penetrating salt-resistant pine wood and entering the cell wall to oxidize thiols and indoles within the cells.

[0026] This treatment method does not damage and can keep salt-resistant pine wood odorless for a long time, while preventing the volatilization of harmful gases. In addition, the hydrogen peroxide used in this invention is a diluted hydrogen peroxide solution, and the surfactant used is disodium cocoyl ethanolamide sulfosuccinate monoester (DMSS), which is low in cost, widely available, and has simple process conditions that are easy to implement. Attached Figure Description

[0027] Figure 1 The image shows the results obtained using solid-phase microextraction and gas chromatography-mass spectrometry (GC-MS) to combat the effects of salt-tolerant wood flour. Detailed Implementation

[0028] To make the objectives and advantages of this invention clearer, the invention will be specifically described below in conjunction with embodiments and accompanying drawings. It should be understood that the following text is merely used to describe one or more specific embodiments of the invention and does not strictly limit the scope of protection specifically claimed by the invention.

[0029] The object of processing in this embodiment is salt-resistant pine wood.

[0030] like Figure 1 As shown, in order to effectively remove the odor of salt-resistant tamarisk wood, we used solid-phase microextraction and gas chromatography-mass spectrometry to detect the wood powder of salt-resistant tamarisk wood. We found that the substances that cause the odor of salt-resistant tamarisk wood are thiols and indole.

[0031] Example 1: A deodorization process using two compounds, thiol and indole, was implemented.

[0032] The specific process steps are as follows:

[0033] S1. Sample preparation:

[0034] a) Dilute the commercially available 30% hydrogen peroxide solution to a 5% hydrogen peroxide solution and set aside;

[0035] b) In the container, add 5.4 liters of 5% hydrogen peroxide solution, 1.8 liters of surfactant, and 10.8 liters of water, and stir well at room temperature for standby;

[0036] c) Cut the anti-salt Zhimuya wood board into 60 cm x 30 cm x 6 cm (T x R x L, where T represents the chord direction, R represents the radial direction, and L represents the longitudinal direction) samples with a saw machine.

[0037] S2, sample immersion: Put the anti-salt Zhimuya sample into the container containing the immersion liquid, the immersion temperature is 25℃, and the immersion time is 2 days.

[0038] S3, sample cleaning: Pour out the hydrogen peroxide immersion liquid in the container, rinse with tap water for three times, add tap water for soaking, and after 24h, transfer to a cool and ventilated place for air drying.

[0039] Example 2

[0040] The processing object of this example is anti-salt Zhimuya wood.

[0041] The specific process steps are as follows:

[0042] S1, sample preparation:

[0043] a) Dilute the 30% hydrogen peroxide solution sold on the market to 7% hydrogen peroxide solution for standby;

[0044] b) In the container, add 8 liters of 7% hydrogen peroxide solution, 4 liters of surfactant, and 8 liters of water, and stir well at room temperature for standby;

[0045] c) Cut the anti-salt Zhimuya wood board into 60 cm x 40 cm x 8 cm (T x R x L, where T represents the chord direction, R represents the radial direction, and L represents the longitudinal direction) samples with a saw machine.

[0046] S2, sample immersion: Put the anti-salt Zhimuya sample into the container containing the immersion liquid, the immersion temperature is 30℃, and the immersion time is 2 days.

[0047] S3, sample cleaning: Pour out the hydrogen peroxide immersion liquid in the container, rinse with tap water for three times, add tap water for soaking, and after 24h, transfer to a cool and ventilated place for air drying.

[0048] Example 3

[0049] The processing object of this example is anti-salt Zhimuya wood.

[0050] The specific process steps are as follows:

[0051] S1, sample preparation:

[0052] a) Dilute the commercially available 30% hydrogen peroxide solution to 10% hydrogen peroxide solution for standby;

[0053] b) Add 7 liters of 10% hydrogen peroxide solution, 3 liters of surfactant and 5 liters of water into a container, and stir well at room temperature for standby;

[0054] c) Cut the anti-salt coppice wood board into 80 cm x 45 cm x 9 cm (T x R x L, where T represents chord direction, R represents radial direction, and L represents longitudinal direction) samples with a saw machine.

[0055] S2, sample immersion: Put the anti-salt coppice wood sample into a container containing the immersion liquid, and immerse at 45°C for 2 days.

[0056] S3, sample cleaning: Pour out the hydrogen peroxide immersion liquid in the container, rinse several times with tap water, add tap water for immersion, and after 24 hours, transfer to a cool and ventilated place for air drying.

[0057] The anti-salt coppice wood treated by deodorization in the above examples was evaluated for odor grade, and the evaluation method was according to GB / T 10220-2012 "General Sensory Analysis Methodology". The specific method and standard are as follows: 5 odor testers were selected to form an odor determination group to evaluate the odor of the deodorized coppice wood. The odor testers were between 18 and 45 years old, did not smoke or drink, could not wear cosmetics, could not have rhinitis, and could not wear shoes with freshly polished shoes. In addition, the olfactory organs were free of disease, the olfactory detection was qualified, and the odor testers were trained by the government environmental protection department and could distinguish five single odors: flower fragrance, sweat smell, sweet rice crust smell, mature fruit smell and fecal odor. They had worked in the government environmental protection department. Odor grade standard: 0: no odor; 1: slightly perceptible odor (detection threshold); 2: weak odor that can be recognized as an odor (cognition threshold); 3: easily perceptible odor; 4: strong odor; 5: strong odor. 5 odor testers evaluated the odor grade of each sample, and the average value was taken. The results are shown in Table 1. The color of the samples was measured using a colorimeter. From the results, the L*, a* and b* of the anti-salt coppice wood changed very little after deodorization, indicating that the color of the anti-salt coppice wood did not change greatly after deodorization; the △E* values of the three examples were all less than 3, indicating that the color change was difficult to detect with the naked eye.

[0058] Table 1: Odor grade evaluation and color change of anti-salt coppice wood

[0059]

[0060] In the process of the present application, hydrogen peroxide can oxidize the volatile organic compounds that produce odor in salt-resistant branch wood, i.e. mercaptan and indole, and the surfactant helps the impregnating solution penetrate into the wood, avoiding the disadvantage that hydrogen peroxide changes the color of the wood while removing the odor of the wood. The present treatment method realizes the effect of removing the odor of salt-resistant branch wood while keeping the color of the wood basically unchanged at a low cost; has a small influence on the macroscopic and microscopic morphology of the salt-resistant branch wood, and does not release odor gas during storage after the deodorization treatment; ensures the effect of removing odor while not damaging the color and morphology of the branch wood, and does not need subsequent treatment.

[0061] The present application utilizes the oxidizing property of hydrogen peroxide to oxidize the mercaptan and indole that produce odor in salt-resistant branch wood, thereby eliminating the odor, while not changing the color and macroscopic and microscopic morphology of the salt-resistant branch wood. The addition of DMSS, a surfactant, makes hydrogen peroxide enter the interior of the salt-resistant branch wood to the maximum extent, and promotes the reaction; at the same time, the equipment used in the process is simple, the steps are less, the cost is low, and the feasibility is high.

[0062] The embodiments of the present application are described in detail above in combination with examples, but the present application is not limited to the above-described embodiments, and for those skilled in the art, after knowing the content described in the present application, a number of equivalent transformations and substitutions can be made without departing from the principles of the present application, and these equivalent transformations and substitutions should also be regarded as belonging to the protection scope of the present application.

Claims

1. A method of removing the salt-lilac wood odor from wood, characterized by: The method includes the following steps: Step 1: Prepare the hydrogen peroxide impregnation solution and set aside. Step 2: Immerse the salt-resistant tamarisk wood in the hydrogen peroxide impregnation solution; Step 3: Take out the salt-resistant tamarisk wood that has been soaked for the preset time, rinse it with clean water and soak it in clean water; Step 4: After soaking for the preset time, remove the salt-resistant tamarisk wood and place it in the atmosphere to allow it to air dry. Wherein: the hydrogen peroxide impregnation solution comprises the following components: a hydrogen peroxide solution with a volume concentration of 5% to 12%, a surfactant and water, wherein the volume ratio of the 5% to 12% hydrogen peroxide solution, the surfactant and water is (3 to 4): (1 to 2): (6 to 4), and the surfactant is disodium cocoyl ethanolamide sulfosuccinate monoester.

2. A method of removing the odor of salt cedar wood according to claim 1, characterized in that: The 5%–12% hydrogen peroxide solution is prepared by mixing 12.5–25 ml of water with every 5 ml of 30% hydrogen peroxide solution.

3. The method of removing the odor of salt cedar wood according to claim 1, characterized in that: The preset soaking time is 2 to 4 days.

4. The method of removing the odor of salt cedar wood according to claim 1, characterized in that: The preset soaking time is 1 to 2 days.

5. The method of removing the odor of salt cedar wood according to claim 1, characterized in that: The temperature of the hydrogen peroxide impregnation solution is 25–40°C.

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