Method for separating vascular bundle plant fibers from parenchyma tissues
By treating the grass with a low-concentration NaOH solution and sampling in batches using the density method, combined with a flat-plate pulp screen to separate the vascular bundles and parenchyma of the grass raw materials, the problems of complex and high-cost separation methods in the existing technology were solved, and efficient and low-cost tissue separation and subsequent pulping optimization were achieved.
Patent Information
- Application Number
- CN202511183984.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-22
- Publication Date
- 2025-10-10
AI Technical Summary
Existing methods for separating vascular tissue and parenchyma tissue from grass raw materials have complex steps and tedious operations, low separation purity, and are prone to damage to cell structure. Chemical and biological methods are also costly.
Bamboo and bagasse were treated with low-concentration NaOH solution, and samples were taken in batches using the density method. The vascular tissue and parenchyma tissue were separated by alkali treatment and a flat screen pulper with a sieve size of 0.2 mm. The temperature and time were controlled to maintain the integrity of the cell structure.
It achieves simple and efficient separation of vascular tissue and parenchyma tissue, with intact cell structure, improved separation purity and subsequent pulping efficiency, reduced liquid medicine consumption and energy consumption, and is suitable for high-performance pulp preparation of bamboo and bagasse.
Smart Images
Figure CN120759144A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of grass raw material processing and utilization, in particular to a method for separating vascular plant fibers and parenchyma tissue. Background Art
[0002] Bamboo and bagasse are important renewable resources with advantages such as a short growth cycle, high yield, and high strength. They are widely used in construction, furniture, papermaking and other fields. Observing the cross-section of bamboo and bagasse, it can be found that they are mainly composed of two parts: vascular tissue and parenchyma tissue. The vascular tissue is composed of fiber cells and has high strength and toughness; while the parenchyma tissue is composed of thin-walled cells and has low strength. In most grass raw materials such as bamboo, bagasse, rice straw and wheat straw, thin-walled cells account for more than 1 / 3. The parenchyma tissue resources are huge and have great potential for utilization. In addition, the presence of thin-walled cells will affect the uniformity of cooking, reduce the pulp yield, increase the consumption of liquid medicine, and cause difficulties in water filtration.
[0003] Therefore, effectively separating the vascular tissue and parenchyma tissue in the raw materials is of great significance for improving the utilization value of grass raw materials. At present, the separation methods of vascular tissue and parenchyma tissue of grass raw materials mainly include density method, mechanical method, chemical method and biological method, which can separate the two cell tissues to a certain extent. However, the existing methods for separating vascular tissue and parenchyma tissue of grass still have some problems. First, the traditional separation methods have complicated steps, cumbersome operations, low separation purity, and easily lead to the destruction of cell structure. The fiber cells and parenchyma cells after being ground into fine powder are not suitable for the subsequent pulping and cooking process. In addition, the reagent consumption used in the chemical method and the biological method is large, and the cost is high.
[0004] Therefore, it is of practical significance to develop a simple, efficient, high-purity separation method for vascular tissue and parenchyma tissue that can maintain cell structural integrity. Summary of the Invention
[0005] In order to solve the above technical problems existing in the prior art, the present invention provides a method for separating vascular plant fibers and parenchyma tissue.
[0006] A method for separating vascular plant fibers and parenchyma tissue in bamboo material comprises the following steps: (1) After removing the green and yellow bamboo materials, the core material is obtained, cleaned, dried, and placed in a sealed bag to balance the moisture; (2) Add NaOH solution with a concentration of 3-12% and keep it at 50-120°C for 30-120 minutes for alkali treatment; (3) After the alkali treatment, the mixture obtained is separated into vascular tissue and parenchyma using a flat screen pulp machine. The screen size of the screen pulp machine is 0.2 mm. The long fibers remaining on the screen plate are collected to obtain vascular tissue; the pulp passing through the screen gap is collected to obtain parenchyma.
[0007] Furthermore, the core material in step (1) is processed into a rod-shaped structure with a length, width and height of 0.5×0.5×2 cm.
[0008] Furthermore, the drying after cleaning in step (1) is specifically to clean the surface dust with water and then air dry naturally.
[0009] Furthermore, the moisture equilibration time in the sealed bag in step (1) is 24 hours.
[0010] Furthermore, the concentration of the NaOH solution in step (2) is 3-12% by mass (w / v).
[0011] Furthermore, in step (2), the material-liquid ratio of the NaOH solution to the core material is 1:10.
[0012] Furthermore, the method further includes step (4) of drying the vascular tissue and the parenchyma tissue to an absolute dry state at a drying temperature of 60 ± 3 °C.
[0013] Furthermore, in step (2), the specific conditions are alkali concentration of 7%, maximum temperature of 90°C, and insulation time of 90 min.
[0014] A method for separating vascular tissue and parenchyma tissue of bagasse by batch sampling using a density method comprises the following steps: (1) Sieve the bagasse through a 10-mesh sieve. The bagasse that remains on the sieve is the de-pithed bagasse, and the bagasse that passes through the sieve is the pith. The pith and de-pithed bagasse are stored in plastic bags respectively. (2) Place the pith and de-pithed bagasse in water, stir, and then let it stand. According to the density method, the parenchyma tissue floats and the fibrous tissue sinks. Take the sinking part in batches, take the sinking part every certain period of time, and finally take the remaining floating part. Dry each component and store it. The first two groups of sinking components of the de-pithed bagasse are used as vascular tissue, and the floating components of the pith component after soaking for 11 to 12 hours are used as parenchyma tissue.
[0015] Compared with the prior art, the technical effects created by the present invention are embodied in: The present application provides a low-concentration alkali pretreatment method for bamboo and bagasse to separate vascular bundle tissue and parenchyma tissue by density method batch sampling, which can effectively separate vascular bundle tissue and parenchyma tissue under mild conditions, and the parenchyma tissue in slurry state can be obtained during the separation process. The bagasse raw material is obtained by the density method batch sampling, which is simple to operate, and the vascular bundle tissue and parenchyma tissue rich in fiber cells and parenchyma cells are obtained, and the cell structure is intact without being damaged. The yield of bamboo vascular bundle tissue and parenchyma tissue is 65.39% and 9.76% respectively, and the yield of bagasse vascular bundle tissue and parenchyma tissue is 16.44% and 27.67% respectively. The vascular bundle tissue of bamboo and bagasse separated by the method of the present application can be prepared into high-performance pulp by subsequent alkali cooking process, which has the advantages of high cellulose content, good drainage, and low inorganic content. In addition, the parenchyma tissue separated by the method of the present application has been pulped under mild alkali treatment, and the density method prolongs the soaking time to separate most of the parenchyma tissue, and the subsequent cooking process can reduce energy consumption, save chemical consumption and cost, and the mild alkali treatment and density method batch sampling can be appropriately adjusted to other grass raw materials by adjusting the reaction conditions, soaking time and other factors. BRIEF DESCRIPTION OF DRAWINGS
[0016] Figure 1 are scanning electron microscope images and physical images of the separated vascular bundle tissue (a) and parenchyma tissue (b).
[0017] Figure 2 are fiber analysis diagrams of the vascular bundle tissue (a) and parenchyma tissue (b) separated in Example 4.
[0018] Figure 3 are the yield of vascular bundle tissue (a) and the yield of parenchyma tissue (b) separated in Examples 1-4.
[0019] Figure 4 are scanning electron microscope cross-section images and physical images of the vascular bundle tissue (a) and parenchyma tissue (b) separated in Example 5.
[0020] Figure 5 are fiber analysis diagrams of the vascular bundle tissue (a) and parenchyma tissue (b) separated in Example 5. DETAILED DESCRIPTION
[0021] Example 1 The present example provides a method for separating bamboo vascular bundle tissue and parenchyma tissue, comprising the following steps: Step 1: After removing the bamboo green and bamboo yellow of the bamboo, the core material is obtained, which is treated into a rod-shaped structure with a length, width and height of 0.5×0.5×2 cm, and is placed in a sealed bag for 24 h to balance the moisture, and the same is used as the raw material.
[0022] Specifically, first select fresh bamboo, use the knife and art knife to remove the bamboo green layer and the bamboo yellow layer completely, and keep the middle core material part. The core material is the most valuable part of the bamboo, which contains abundant vascular bundle tissue and parenchyma. The obtained core material is cut into a cuboid rod structure with uniform specifications, and the size is strictly controlled to be 2 cm long, 0.5 cm wide and 0.5 cm high. During the cutting process, the cutting surface needs to be kept flat to avoid burrs or irregular edges, so as to ensure the uniformity of subsequent processing. After cutting, the sample surface is washed with tap water to remove debris and dust during processing. After natural air drying, the rod-shaped core material is placed in a plastic bag with good sealing performance, and sealed for 24 h to make the internal moisture reach a balanced state. The purpose of this step is to make the moisture in the core material uniform, and to create conditions for subsequent alkali treatment.
[0023] Step 2: Weigh the experimental amount of raw materials, add different conditions of NaOH with concentrations of 3%, 5%, 7%, 9% and 12%, and supplement water to make the liquid ratio reach 1:10, then perform alkali treatment at 90 ℃ for 90 min.
[0024] Specifically, the bamboo core material after balancing the moisture in step 1 is taken out, and an appropriate amount of raw material is weighed using a precision balance for the experiment. According to the experimental design, NaOH solutions with mass fraction concentrations of 3%, 5%, 7%, 9% and 12% are prepared. When preparing, first weigh the corresponding mass of NaOH solid, then add deionized water to dissolve and prepare the solution with the required concentration. The weighed bamboo core material is placed in a reaction container, and the prepared NaOH solution is added. The liquid-solid ratio is adjusted to 10:1, that is, 10 milliliters of total liquid is added for every 1 gram of absolute dry bamboo core material. Ensure that the bamboo is completely immersed in the solution to avoid being exposed above the liquid surface. Place the reaction container in a constant temperature water bath or constant temperature reactor, control the temperature to be stable at 90 ℃, and the incubation time is 90 min. During the treatment process, appropriate stirring can be performed to ensure uniform reaction. The purpose of alkali treatment is to destroy the lignin and hemicellulose structure in the bamboo, weaken the connection between the vascular bundle tissue and the parenchyma, and facilitate subsequent separation.
[0025] Step 3: After treatment, the obtained mixture is separated into vascular bundle tissue and parenchyma by using a flat screen pulp machine, the screen gap size of the screen pulp machine is 0.2 mm, the long fibers retained on the screen plate are collected to obtain the vascular bundle tissue, and the pulp passing through the screen gap is collected to obtain the parenchyma. The vascular bundle tissue and the parenchyma are dried to an absolute dry state, and the drying temperature is 60±3 ℃.
[0026] Specifically, after the alkali treatment is completed, the reaction container is taken out of the constant temperature environment and allowed to cool to room temperature. The treated mixture is poured into a flat screen pulp machine for separation operation. The flat screen pulp machine used is equipped with a screen plate with a screen gap size of 0.2 mm, which can effectively separate the vascular bundle tissue and parenchyma tissue. Start the screen pulp machine, and under appropriate hydraulic action, the parenchyma tissue will flow out through the screen gap, while the longer vascular bundle tissue will remain on the screen plate. During the separation process, clean water can be added appropriately to assist in washing, to improve the separation efficiency. After the separation is completed, the vascular bundle tissue on the screen plate and the parenchyma tissue pulp passing through the screen gap are collected respectively. The two collected tissues are transferred to a drying container respectively and placed in an oven with a temperature control of 60±3°C for drying treatment. The drying process continues until the sample is absolutely dry, i.e., the sample mass no longer changes. After the drying is completed, the sample is taken out and sealed for storage to prevent moisture absorption.
[0027] Example 2 The present embodiment provides a method for separating vascular bundle tissue and parenchyma tissue of bamboo, comprising the following steps: Step 1: After removing the green layer and yellow layer of the bamboo, the core material is obtained, which is treated into a rod-shaped structure with a length of 0.5 cm, a width of 0.5 cm and a height of 2 cm, and is placed in a sealed bag for 24 h to balance the moisture, which is used as the raw material.
[0028] Specifically, bamboo with appropriate growth period is selected, and professional tools are used to completely strip the green layer on the outer layer and the yellow layer on the inner layer of the bamboo, and the core material in the middle part is reserved. The core material of the bamboo is the most valuable part of the bamboo stem, which contains rich vascular bundle tissue and parenchyma tissue. The obtained core material is cut into regular rod-shaped structures with a length of 2 cm, a width of 0.5 cm and a height of 0.5 cm according to the precise size requirements. During the cutting process, sharp cutting tools are used to ensure that the cutting surface is smooth and flat, and irregular edges or fractures are avoided. After cutting, the sample surface is washed with tap water to remove debris and dust generated during the treatment process. After natural air drying, the rod-shaped core material is placed in a plastic bag with good sealing performance and sealed for 24 hours to balance the internal moisture. The purpose of this step is to make the moisture in the core material uniform, to create conditions for subsequent alkali treatment and to improve the consistency of the treatment effect.
[0029] Step 2: A certain amount of raw material is weighed, 9% NaOH is added, and water is supplemented to make the liquid ratio reach 1:10, and then the alkali treatment is carried out at 90°C for different time periods, i.e., 30, 60, 90, 105 and 120 min.
[0030] Specifically, remove the bamboo core material after moisture equilibration in Step 1 and use a precision balance to weigh the appropriate amount of raw material for the experiment. Prepare a 9% NaOH solution by weighing the appropriate amount of solid NaOH and dissolving it in deionized water to obtain a 9% solution. Place the weighed bamboo core material into a reaction vessel and add the prepared 9% NaOH solution, adjusting the liquid-to-solid ratio to 10:1 (add 10 ml of total liquid for every gram of absolutely dry bamboo core material). Ensure that the bamboo is completely immersed in the solution, avoiding any exposure above the liquid surface. Place the reaction vessel in a constant temperature water bath or reactor, maintaining a constant temperature of 90°C. According to the experimental design, heat treatments were performed for 30, 60, 90, 105, and 120 minutes, respectively. Stirring was performed during the treatments to ensure uniform reaction. The purpose of the different alkaline treatment periods was to investigate the effect of treatment time on the separation of vascular tissue and parenchyma tissue and to identify the optimal treatment time.
[0031] Step 3: After the treatment, the mixture is separated into vascular tissue and parenchyma using a flat screen with a 0.2 mm sieve size. The long fibers remaining on the sieve plate are collected to obtain the vascular tissue; the pulp passing through the sieve is collected to obtain the parenchyma. The vascular tissue and parenchyma are dried to absolute dryness at a drying temperature of 60±3°C.
[0032] Specifically, after each alkali treatment period, the reaction vessel was removed from the constant temperature environment and allowed to cool to room temperature. The treated mixture was then poured into a flat-plate screen for separation. The screen was equipped with a sieve plate with a 0.2 mm slit size, which effectively separates the vascular tissue from the parenchyma tissue. The screen was started, and under appropriate hydraulic pressure, the parenchyma tissue flowed out through the slits, while the longer vascular tissue remained on the plate. During the separation process, water was added to aid rinsing to improve separation efficiency. After separation, the vascular tissue on the plate and the parenchyma tissue slurry that passed through the slits were collected separately. The two collected tissues were transferred to drying containers and dried in an oven controlled at 60 ± 3°C. The drying process continued until the sample reached absolute dryness, meaning that the sample mass no longer changed. After drying, the sample was removed and sealed to prevent moisture absorption.
[0033] Example 3 This embodiment provides a method for separating bamboo vascular tissue and parenchyma tissue, comprising the following steps: Step 1: After removing the green and yellow parts of the bamboo, the core material is obtained. The core material is processed into a rod-shaped structure with a length, width and height of 0.5 × 0.5 × 2 cm, and placed in a sealed bag to balance the moisture for 24 hours. This is used as the raw material.
[0034] Specifically, healthy bamboo is selected and, using specialized tools, the outer green layer and inner yellow layer are completely removed, leaving the core material in the middle. The core material is the most structurally stable part of the bamboo, rich in vascular tissue and parenchyma. The resulting core material is cut into uniform rectangular rods, with dimensions strictly controlled to 2 cm in length, 0.5 cm in width, and 0.5 cm in height. The cutting process ensures a smooth surface, avoiding burrs or irregular edges, to ensure uniformity in subsequent processing. After cutting, the sample surface is cleaned with tap water to remove debris and dust from the processing. After air drying, the rod-shaped core material is placed in a well-sealed plastic bag and sealed for 24 hours to allow the internal moisture to reach equilibrium. This step aims to evenly distribute the moisture in the core material, creating conditions for subsequent alkaline treatment and improving the consistency and repeatability of the treatment results.
[0035] Step 2: Weigh the experimental amount of raw materials, add 9% NaOH, and add water to make the liquid ratio reach 1:10, then keep it at different temperatures (50, 70, 90, 105, and 120 °C) for 90 min for alkali treatment.
[0036] Specifically, remove the bamboo core material after moisture equilibration in Step 1 and use a precision balance to weigh the appropriate amount of raw material for the experiment. Prepare a 9% NaOH solution by weighing the appropriate amount of solid NaOH and dissolving it in deionized water to create a 9% solution. Place the weighed bamboo core material into a reaction vessel and add the prepared 9% NaOH solution, adjusting the liquid-to-solid ratio to 10:1 (add 10 ml of total liquid for every gram of absolutely dry bamboo core material). Ensure that the bamboo is completely immersed in the solution, avoiding any exposure above the liquid surface. The reaction vessel is placed in a constant temperature environment controlled at 50°C, 70°C, 90°C, 105°C, and 120°C, respectively, for 90 minutes each. Stirring may be performed to ensure uniform reaction. The purpose of the alkali treatment at different temperatures is to investigate the effect of treatment temperature on the separation of vascular tissue and parenchyma tissue and to identify the optimal treatment temperature. It should be noted that when the temperature exceeds 100 °C, a pressure vessel must be used to prevent the solution from boiling and causing changes in experimental conditions.
[0037] Step 3: After the treatment, the mixture is separated into vascular tissue and parenchyma using a flat screen with a 0.2 mm sieve size. The long fibers remaining on the sieve plate are collected to obtain the vascular tissue; the pulp passing through the sieve is collected to obtain the parenchyma. The vascular tissue and parenchyma are dried to absolute dryness at a drying temperature of 60±3°C.
[0038] Specifically, after the alkali treatment at each temperature is completed, the reaction vessel is removed from the constant temperature environment and allowed to cool to room temperature. The treated mixture is then poured into a flat-plate screen for separation. The screen is equipped with a sieve plate with a 0.2 mm slit size, which effectively separates the vascular tissue from the parenchyma tissue. When the screen is started, under appropriate hydraulic pressure, the parenchyma tissue flows out through the slits, while the longer vascular tissue remains on the plate. During the separation process, water can be added to aid rinsing to improve separation efficiency. After separation, the vascular tissue on the plate and the parenchyma tissue slurry that has passed through the slits are collected separately. The two collected tissues are transferred to drying containers and dried in an oven controlled at 60 ± 3°C. The drying process continues until the sample reaches absolute dryness, meaning that the sample mass no longer changes. After drying, the sample is removed and sealed to prevent moisture absorption.
[0039] Embodiment 4: Among the vascular tissue and parenchyma tissue obtained under the different reaction conditions provided in Examples 1 to 3, the yield of parenchyma tissue was the highest under the conditions of 7% alkali concentration, 90°C maximum temperature, and 90 min holding time. This condition was used for the experiment, and other conditions remained unchanged.
[0040] When the alkali concentration is lower than 7%, the reaction conditions are weak, and the parenchyma tissue near the vascular bundle is less separated, so the yield is low. When the alkali concentration is higher than 7%, the reaction conditions are strong, and the parenchyma tissue may be "overcooked", so the yield decreases.
[0041] Example 5 This embodiment provides a method for separating bagasse vascular tissue and parenchyma tissue, comprising the following steps: Step 1: Sieve the bagasse through a 10-mesh sieve. The residue remaining on the sieve is the de-pithed bagasse, and the residue passing through the sieve is the pith. Store the pith and de-pithed bagasse separately in plastic bags.
[0042] Specifically, the washed and fully dried bagasse raw material was selected, and the experimental amount of bagasse was sieved through a 10-mesh standard sieve. The part passing through the sieve was the pith, and the part remaining on the sieve was the de-pithed bagasse. The two raw materials were sealed and stored for the next experiment.
[0043] Step 2: Place the pith and de-pithed bagasse in water, stir, and let it stand. Density analysis indicates that the parenchyma will float and the fibrous tissue will sink. Remove the sinking fraction in batches, taking it at regular intervals. Dry each fraction and store it.
[0044] Specifically, appropriate amounts of the de-pithed bagasse and sugarcane pith from step 1 were used in the experiment. Both materials were placed in a beaker, thoroughly stirred with a predetermined amount of deionized water, and then allowed to stand until completely immersed. After soaking for one hour, the sinking fraction was removed. Samples were taken every hour, and finally, after soaking for 11 to 12 hours, the remaining floating fraction was collected. The first two sinking fractions of the de-pithed bagasse were used as vascular tissue, and the floating fraction of the sugarcane pith, which had been soaked for more than 11 hours, was used as parenchyma tissue. Both materials were then dried to absolute dryness at a temperature of 60 ± 3°C.
[0045] Finally, it should be noted that the above embodiments are merely representative examples of the present invention. Obviously, the technical solutions of the present invention are not limited to the above embodiments and are subject to numerous variations. All variations that can be directly derived or conceived by a person of ordinary skill in the art from the disclosure of the present invention should be considered within the scope of protection of the present invention.
Claims
1. A method for separating vascular plant fibers and parenchyma tissue in bamboo, characterized in that: The steps include: (1) After removing the green and yellow bamboo materials, the core material is obtained, cleaned, dried, and placed in a sealed bag to balance the moisture; (2) Add NaOH solution with a concentration of 3-12% and keep it at 50-120°C for 30-120 minutes for alkali treatment; (3) After the alkali treatment, the mixture obtained is separated into vascular tissue and parenchyma using a flat screen pulp machine. The screen size of the screen pulp machine is 0.2 mm. The long fibers remaining on the screen plate are collected to obtain vascular tissue; the pulp passing through the screen gap is collected to obtain parenchyma.
2. The method for separating vascular plant fibers and parenchyma tissue according to claim 1, wherein: The core material in step (1) is processed into a rod-shaped structure with a length, width and height of 0.5×0.5×2 cm.
3. The method for separating vascular plant fibers and parenchyma tissue according to claim 1, wherein: The drying after cleaning in step (1) is specifically to clean the surface dust with water and then air dry naturally.
4. The method for separating vascular plant fibers and parenchyma tissue according to claim 1, wherein: The moisture equilibration time in the sealed bag in step (1) is 24 hours.
5. The method for separating vascular plant fibers and parenchyma tissue according to claim 1, wherein: The concentration of the NaOH solution in step (2) is 3-12% by mass.
6. The method for separating vascular plant fibers and parenchyma tissue according to claim 1, characterized in that: In step (2), the material-liquid ratio of the NaOH solution to the core material is 1:
10.
7. The method for separating vascular plant fibers and parenchyma tissue according to claim 1, characterized in that: The method further includes step (4) of drying the vascular tissue and the parenchyma tissue to an absolute dry state at a drying temperature of 60 ± 3 °C.
8. The method for separating vascular plant fibers and parenchyma tissue according to claim 1, characterized in that: In the step (2), the specific conditions are alkali concentration of 7%, maximum temperature of 90°C, and insulation time of 90 min.
9. A method for separating vascular tissue and parenchyma tissue of bagasse by batch sampling using a density method, characterized in that: The steps include: (1) Sieve the bagasse through a 10-mesh sieve. The bagasse remaining on the sieve is the de-pithed bagasse, and the bagasse passing through the sieve is the pith. (2) Place the pith and de-pithed bagasse in water, stir, and then let it stand. According to the density method, the parenchyma tissue floats and the fibrous tissue sinks. Take the sinking part in batches, take the sinking part every certain period of time, and finally take the remaining floating part. Dry each component and store it. The first two groups of sinking components of the de-pithed bagasse are used as vascular tissue, and the floating components of the pith component after soaking for 11 to 12 hours are used as parenchyma tissue.