阅读说明：本技术 一种化学机械法从植物中提取木糖的综合利用方法 (Comprehensive utilization method for extracting xylose from plants by chemical mechanical method ) 是由 樊慧明 刘青君 牟洪燕 黄瑾 董晓斌 于 2019-10-22 设计创作，主要内容包括：本发明公开了一种化学机械法从植物中提取木糖的综合利用方法。该方法为：先将全杆农业废弃物经过机械挤压预处理,随后将挤压后的植物原料,加入碱溶液浸渍,充分搅拌使其浸渍均匀；然后通过机械磨浆处理,结束后转移至反应釜中,洗涤并固液分离,得到的黑液,待降至室温后,加入酸液调节pH,沉出碱液中溶解的木质素,固液分离后,木质素可以作为热源或者通过改性得到工业化应用原料,上清液用碱液调节pH,搅拌后加入乙醇溶液,得到高纯度木糖。本发明不仅可以高效提取生物质内的木糖,而且得到的纤维形态良好,可以进行造纸资源再利用,从而使木材、芦苇、麦草、甘蔗渣等农业废弃物得到最大化的综合利用。(The invention discloses a comprehensive utilization method for extracting xylose from plants by a chemical mechanical method. The method comprises the following steps: firstly, mechanically extruding and pretreating the whole-stalk agricultural wastes, then adding an alkali solution into the extruded plant raw materials for soaking, and fully stirring to ensure that the plant raw materials are uniformly soaked; and then mechanically grinding the mixture, transferring the mixture into a reaction kettle after the mechanical grinding treatment is finished, washing and carrying out solid-liquid separation to obtain black liquor, adding acid liquor to adjust the pH value after the black liquor is cooled to room temperature, precipitating lignin dissolved in alkali liquor, carrying out solid-liquid separation, using the lignin as a heat source or obtaining industrial application raw materials through modification, adjusting the pH value of supernatant liquor by using the alkali liquor, and adding an ethanol solution after stirring to obtain the high-purity xylose. The invention not only can efficiently extract xylose in biomass, but also can obtain fiber with good shape, and can recycle papermaking resources, thereby enabling agricultural wastes such as wood, reed, wheat straw, bagasse and the like to be comprehensively utilized to the maximum extent.)

1. A comprehensive utilization method for extracting xylose from plants by a chemical mechanical method is characterized by comprising the following steps:

firstly, mechanically extruding and pretreating all-stalk agricultural wastes, then adding alkali solution into the extruded plant raw materials for soaking until the solid-liquid ratio is 1:2 ~: 12g/mL and the alkali-soluble mass percentage concentration is 2% ~%, fully stirring to enable the plant raw materials to be uniformly soaked, then mechanically grinding the plant raw materials into slurry for 1 ~ 10min, transferring the slurry into a reaction kettle after the completion of the mechanical grinding treatment, continuously reacting for 10 ~ min at 100 ℃ of ~ ℃ and 0.142 ~ MPa, after the reaction is completed, washing and carrying out solid-liquid separation, carrying out subsequent comprehensive utilization on fiber solid residues as fiber raw materials, obtaining black liquor, cooling the black liquor to room temperature, adding acid liquor to adjust the pH to 2 ~, precipitating lignin dissolved in the alkali liquor, after the solid-liquid separation, using the lignin as a heat source or modifying to obtain industrial application raw materials, adjusting the pH of supernatant to 5 ~ by using the alkali liquor, fully stirring, adding ethanol solution in an amount which is 1 ~ times that of the lignin is dissolved in the alkali liquor, carrying out alcohol precipitation, centrifugal separation and purification to obtain high-purity xylose.

2. The method as claimed in claim 1, wherein the agricultural waste is wood, corn stalk, reed, wheat straw or bagasse.

3. The method of claim 1, wherein the mechanical pressing step is a screw press.

4. The process of claim 1, wherein the alkaline solution is a sodium hydroxide solution or a potassium hydroxide solution.

5. The process of claim 1, wherein the mechanical refining process is a multi-tooth refining apparatus.

6. The comprehensive utilization method for extracting xylose from plants by the chemical mechanical method as claimed in claim 1, characterized in that the reaction kettle is a thermostatic water bath, an autoclave or a digester.

7. The method of claim 1, wherein the pH of the acid solution is adjusted to glacial acetic acid, hydrochloric acid, or sulfuric acid.

Technical Field

The invention belongs to the field of comprehensive utilization of agricultural waste resources such as wood, reed, wheat straw, bagasse and the like, and particularly relates to a method for efficiently extracting xylose from plant fibers by combining chemical mechanical methods.

Background

Xylose, a natural, healthy, nutritive sweetener, is considered to be a carbohydrate in its broadest sense, and may also be narrowly defined as a polyol. At present, the natural xylose has the sweetness equivalent to that of cane sugar, is low in heat, slow and limited in digestion, can be widely applied to multiple fields such as food, medicines and the like, is a necessary product in the food and medicine field of diabetes patients and the like, is more and more concerned by people, provides wide prospects for replacing cane sugar and glucose as additives in multiple fields, can be used for preparing various chemicals and medicine additives after being modified, and has the advantages that the application field and the market demand are enlarged year by year.

Xylose is widely present in nature in various fruits and vegetables, but is present in small amounts, and therefore is mostly biosynthesized industrially. Every year, the non-wood raw materials such as wood, reed, wheat straw, bagasse and other agricultural wastes contain a large amount of xylose, which is undoubtedly an ideal raw material for producing xylo-oligosaccharide. And the agricultural wastes such as wood, reed, wheat straw, bagasse and the like have larger annual output, low raw material cost and rich sources, but most of the agricultural wastes are discarded or incinerated, so that not only is the resource waste caused, but also huge environmental pollution is caused. Therefore, the renewable plant fiber raw materials are reasonably and effectively developed, so that the economic healthy development and energy conservation can be promoted, and the environment is effectively protected.

However, the current large-scale industrial process for extracting xylose only adopts a single chemical method to extract xylose in the fiber cell wall, and as a result, the extraction rate is low, the chemical dosage is large, the production cost is high, the benefit is low, and the ideal requirement on high-value utilization is not met. The method is inspired by chemi-mechanical pulp, on the premise of chemically treating raw materials, fibers are firstly opened through mechanical treatment, more hemicellulose is exposed, the method is beneficial to impregnation and reaction of chemicals, the extraction rate of xylose can be improved, the using amount of chemicals can be reduced, and the method is more worthy of proposing that after xylose is extracted through a chemi-mechanical method, the fibers still have good fiber performance, and can be used for papermaking, so that the comprehensive and efficient utilization of resources is realized, and the method has important economic significance for realizing commercial production. Meanwhile, an important technical support is provided for producing high value-added products with good market prospects and large profits.

Disclosure of Invention

The main purpose of the invention is to break plant cell walls by combining a physical mechanical method and a chemical method, achieve fibrosis and promote alkali liquor to permeate into fibers, thereby improving the extraction rate of xylan.

The technical scheme of the invention is as follows.

A comprehensive utilization method for extracting xylose from plants by a chemical mechanical method comprises the following steps:

a comprehensive utilization method for extracting xylose from plants by a chemical mechanical method is characterized by comprising the following steps:

firstly, mechanically extruding and pretreating all-stalk agricultural wastes, then adding an alkali solution into the extruded plant raw materials for soaking to ensure that the solid-liquid ratio is 1:2 ~ 1:12g/mL and the alkali concentration is 2% ~ 12%, fully stirring to ensure that the plant raw materials are uniformly soaked, then mechanically grinding into slurry for 1 ~ 10min, transferring the slurry into a reaction kettle after the completion of the mechanical grinding treatment, continuously reacting for 10 ~ 70min at the temperature of 100 ℃ of ~ 121 ℃ and 0.142 of 0.142 ~ 0.165.165 Mpa, washing and carrying out solid-liquid separation after the reaction is completed, using fiber solid residues for later comprehensive utilization as fiber raw materials, adding an acid solution to adjust the pH to 2 ~ 3 after the black liquor is cooled to room temperature, precipitating lignin dissolved in the alkali solution, using the lignin as a heat source or modifying to obtain industrial application raw materials after the solid-liquid separation, using the alkali solution to adjust the pH of supernatant to 5 ~ 6, fully stirring, adding an ethanol solution in an amount which is 1 ~ 4 times that of the lignin is dissolved in the alkali solution, carrying out alcohol precipitation, centrifugal separation and purification to obtain high-purity xylose.

In the method, the biomass raw material is wood, corn stalks, reeds, wheat straws, bagasse and other plants.

In the method, the mechanical extrusion pretreatment is screw extrusion and the like.

In the above method, the alkali solution is sodium hydroxide, potassium hydroxide or the like.

In the method, the mechanical refining is followed by multi-tooth refining equipment and the like.

In the method, the reaction kettle is a constant-temperature water bath, an autoclave, a digester and the like.

In the method, the pH value of the acid solution is adjusted to be glacial acetic acid, hydrochloric acid, sulfuric acid and the like.

Compared with the prior art, the invention has the advantages that:

because the three major components of the plant raw material are intertwined and closely connected with each other, the fibers are connected with each other through lignin in intercellular layers, and a single chemical method cannot fully impregnate the interior of the fibers, so that the extraction rate of the xylose cannot be improved to the maximum extent. The invention provides two-step mechanochemical method treatment combining extrusion, pulp grinding and a chemical method, wherein the method of extrusion is firstly used for promoting cell wall breaking and fiber dissociation, and then pulp grinding treatment is carried out under the action of alkali liquor wetting expansion on the basis to achieve fibrosis, and fibers are opened, so that more hemicellulose is exposed, and the impregnation of liquid medicine is more facilitated. And after the xylose is extracted by the chemical mechanical method, the fiber still has good fiber performance, and can be used for papermaking, so that the comprehensive utilization is more beneficial to the industrial development in the future. The pulping process is simple and easy to operate, the loss in the experimental process is less, and the results show that the mode of combining two mechanical methods and a chemical method promotes the extraction of xylose to a certain extent.

Drawings

Fig. 1 is a comparative experimental diagram of a raw material subjected to a cutting and crushing process and a screw extrusion/refining combined process.

Detailed Description

The present invention will be described in further detail with reference to specific examples, but the embodiments of the present invention are not limited thereto, and may be carried out with reference to conventional techniques for process parameters not particularly noted.