Search

CN-121992677-A - Stepped processing method, system and product of plant fiber superfine powder and application

CN121992677ACN 121992677 ACN121992677 ACN 121992677ACN-121992677-A

Abstract

The application relates to the technical field of plant fiber processing, and discloses a stepped processing method, a system, a product and application of plant fiber superfine powder, wherein the superfine powder consists of 85.2% -91.2% of cellulose, 1.2% -2.9% of ash and the balance lignin and hemicellulose, the particle surface of the superfine powder has a micropore structure formed by steam explosion, the average length-diameter ratio is 21-32, the processing method comprises the steps of performing steam explosion on pretreatment raw materials to dissociate physical structures, purifying cellulose by alkali treatment and removing impurities, and performing supersonic jet milling and turbine classification under the environment of controlled low temperature and inert gas.

Inventors

  • ZHANG CHENGHONG
  • ZHANG PIAOYI
  • DONG HUAGUO
  • FAN CHAO
  • ZHU QING
  • ZHU FU
  • ZHANG CHANGPING

Assignees

  • 金纳多生物工程(山东)有限公司

Dates

Publication Date
20260508
Application Date
20260311

Claims (10)

  1. 1. The step processing method of the plant fiber superfine powder is characterized by comprising the following steps of: placing the pretreated plant fiber raw material in a pressure container, introducing saturated steam, raising the pressure, maintaining the pressure under the raised pressure, then opening a pressure release valve to release the pressure in the pressure container to normal pressure within a preset time, and collecting the explosion product; Adding the blasting product into an alkaline aqueous solution, stirring the blasting product under a heating condition for reaction, carrying out solid-liquid separation after the reaction is finished, washing an obtained filter cake to be neutral by adopting a hot washing liquid, and then carrying out drying treatment to obtain a cellulose intermediate; And (3) filling inert gas into a supersonic jet milling system for replacement, driving the cellulose intermediate to clash and refine by using high-pressure inert gas flow under a controlled low-temperature environment, and obtaining plant fiber superfine powder through turbine grading treatment.
  2. 2. The step processing method of plant fiber superfine powder according to claim 1, wherein the preparation method of the pretreated plant fiber raw material is as follows: Washing the plant fiber raw material with deionized water, and drying at 70-80 ℃ until the water content is 8.0-9.5%; in the saturated steam raising pressure and maintaining pressure maintaining step, the pressure is 1.5-3.0MPa, the maintaining pressure maintaining time is 60-180 s, and the releasing time of the pressure in the pressure container is less than or equal to 0.1s.
  3. 3. The step processing method of plant fiber superfine powder according to claim 1, wherein the alkaline aqueous solution is sodium hydroxide aqueous solution with the mass percent concentration of 3% -10%, and the solid-liquid mass ratio of blasting products to the alkaline aqueous solution is 1 (8-15); The temperature of the stirring reaction is 70-95 ℃ and the time is 1-4 hours; The hot washing liquid is deionized water with the temperature of 80-90 ℃ and is washed until the pH value of the obtained washing liquid is 6.5-7.5.
  4. 4. The step processing method of plant fiber superfine powder according to claim 1, characterized in that the temperature of the drying treatment is 105-110 ℃, and the water content of the cellulose intermediate is controlled to be 1.2% -1.8%; The inert gas is selected from nitrogen or argon, and the volume concentration of oxygen in the supersonic jet milling system is controlled to be lower than 2.0%; the temperature of the low temperature environment is-10 ℃ to 25 ℃; the rotational speed of the turbine classification treatment is set to be 1000-3000r/min.
  5. 5. A system for performing a step processing method of plant fiber ultra-fine powder according to any one of claims 1 to 4, comprising: The steam explosion subsystem comprises a high-pressure steam generator, an explosion tank provided with a quick discharge valve and a cyclone separation collector; The chemical purification subsystem comprises an alkali treatment reaction kettle with a mechanical stirring and temperature control jacket, a centrifugal filter and a vacuum constant temperature oven; An ultra-fine subsystem comprising an inert gas source, an auxiliary cooling unit, a supersonic jet mill and a turbine classifier provided with a classification wheel; The auxiliary cooling unit is connected to a pulverizing chamber of the supersonic jet pulverizer for maintaining circulating gas within the pulverizing chamber at-10 ℃ to 25 ℃.
  6. 6. Plant fiber superfine powder, characterized in that it is prepared by the processing method according to any one of claims 1-4, and comprises the following components in percentage by weight: 85.2 to 91.2 percent of cellulose, 1.2 to 2.9 percent of ash, and the balance of lignin and hemicellulose; The particle surface of the plant fiber superfine powder has a microporous structure formed by steam explosion, and the average length-diameter ratio is 21-32.
  7. 7. The plant fiber ultra-fine powder according to claim 6, wherein the physical characteristic parameters of the plant fiber ultra-fine powder are: The median particle diameter D 50 is 5.8-28.5 μm, the particle size distribution span (D 90 -D 10 ）/D 50 is 1.55-1.95, BET specific surface area is 10.5-18.5m 2 /g).
  8. 8. The plant fiber submicron powder according to claim 6, characterized in that the average polymerization degree of cellulose in the component is 784-845, and the CIE L ∗ brightness value of the plant fiber submicron powder is 82.35-87.56.
  9. 9. The plant fiber superfine powder according to claim 6, wherein the plant fiber superfine powder is prepared from one or more of rice hulls, crushed moso bamboo materials, industrial hemp fibers, crop straws and wood chips.
  10. 10. Use of the plant fiber ultra-fine powder according to any one of claims 6-9 for increasing interfacial bonding strength, improving mechanical properties or improving thermal stability in the preparation of polylactic acid-based composite materials.

Description

Stepped processing method, system and product of plant fiber superfine powder and application Technical Field The invention relates to the technical field of plant fiber processing, in particular to a step processing method and system of plant fiber superfine powder, a product and application. Background Plant fibers, which are a natural biomass raw material rich in resources, are widely used in the field of reinforcing bio-based resins because of their high specific strength, low density and biodegradability. In the existing plant fiber powder processing process, the raw materials are generally refined by adopting the traditional mechanical crushing or ball milling process. The high-strength mechanical shearing action is extremely easy to destroy the intrinsic structure of the fiber, so that the cellulose molecular chain is severely broken, the average length-diameter ratio of the powder is greatly reduced, and an effective reinforced framework is difficult to form in a composite material matrix. At the same time, the local high temperature generated by the mechanical processing can cause thermal degradation and oxidative discoloration of cellulose, affecting the brightness index of the product and the processability in downstream products. In addition, natural plant fibers contain a relatively high proportion of hemicellulose and lignin, and if effective component separation is not performed, the components are extremely easy to decompose in the high-temperature melt processing process of the composite material, volatile substances are generated, defects are formed in the material, and therefore the mechanical strength and the thermal stability of the product are reduced. In the aspect of interface combination, the surface of the plant fiber particles obtained by the conventional process lacks microstructure characteristics, so that the interfacial compatibility of the plant fiber particles with resin matrixes such as polylactic acid and the like is insufficient, and the transmission efficiency of stress among interfaces is low. Therefore, how to achieve fiber ultra-micro while maintaining high aspect ratio and component purity, and improve surface micro-morphology to enhance interface bonding is a technical problem to be solved in current plant fiber recycling. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a step processing method, a system, a product and application of plant fiber superfine powder, solves the problems of mechanical damage, impure components, weak interface binding force and the like in the existing plant fiber processing process, and limits the improvement of the mechanical property and the thermal stability of the plant fiber superfine powder serving as reinforcing filler in a biological matrix composite material. In order to achieve the purpose, the invention is realized through the following technical scheme that the first aspect provides a step processing method of plant fiber superfine powder, which adopts the following technical scheme: A step processing method of plant fiber superfine powder comprises the following steps: Placing the pretreated plant fiber raw material into a pressure container, introducing saturated steam, raising the pressure, maintaining the pressure under the raised pressure, then opening a pressure release valve to release the pressure in the pressure container to normal pressure within a preset time, and collecting the obtained explosion product; Adding the explosion product into an alkaline aqueous solution, stirring for reaction under a heating condition, carrying out solid-liquid separation after the reaction is finished, washing the obtained filter cake to be neutral by adopting a hot washing liquid, and then carrying out drying treatment to obtain a cellulose intermediate; And (3) filling inert gas into a supersonic jet milling system for replacement, driving a cellulose intermediate to clash and refine by using high-pressure inert gas flow under a controlled low-temperature environment, and obtaining plant fiber superfine powder through turbine grading treatment. By adopting the technical scheme, the invention utilizes the cascade treatment flow of physical structure pre-dissociation, chemical component purification and low-temperature mechanical refinement, reduces the structural strength of plant fibers and improves the chemical accessibility of each component. Under saturated steam environment, water enters into the fiber tube cells and the intercellular layers, and the pressure gradient and the volume expansion force generated in the moment of pressure release enable the fiber bundles to be longitudinally peeled along the intercellular layers, so that a uniformly distributed micropore structure is formed on the surfaces of the particles. The process weakens the hydrogen bond binding force between cellulose, hemicellulose and lignin, and increases the effective contact area of subsequent chemical reaction. I