阅读说明：本技术 一种热蒸汽协同生物酶处理麦草制备本色生物机械浆及副产物全利用的方法 (Method for preparing natural-color biomechanical pulp by treating wheat straw with hot steam and biological enzyme and fully utilizing byproducts ) 是由 吉兴香 陈嘉川 田中建 王瑞明 王东兴 刘玉 于 2020-12-31 设计创作，主要内容包括：本发明涉及一种热蒸汽协同生物酶处理麦草制备本色生物机械浆及副产物的方法,属于造纸技术与废弃物综合利用技术领域。本发明提出以全麦草为原料,采用热水协同碱性生物酶处理全麦草制备高强度本色生物机械浆的方法,从而满足生产本色包装纸和纸基材料要求,并对其副产物进行回收制备生物质复合肥,使得固废变废为宝,实现了麦草的高值化全利用。本发明制备方法简单、绿色清洁高效,具有良好的实际应用价值和广阔的应用前景。(The invention relates to a method for preparing true-color biomechanical pulp and byproducts by treating wheat straw with hot steam and biological enzyme, belonging to the technical field of papermaking technology and comprehensive utilization of wastes. The invention provides a method for preparing high-strength natural-color bio-mechanical pulp by using whole wheat straw as a raw material and treating the whole wheat straw by hot water in cooperation with alkaline bio-enzyme, thereby meeting the requirements of producing natural-color packaging paper and paper base materials, recycling byproducts of the natural-color packaging paper and the paper base materials to prepare a biomass compound fertilizer, changing solid wastes into valuables, and realizing high-valued full utilization of the wheat straw. The preparation method is simple, green, clean and efficient, and has good practical application value and wide application prospect.)

1. A method for preparing true-color biomechanical pulp and byproducts by treating wheat straw with hot steam and biological enzyme is characterized by comprising the following steps:

(1) mixing waste wheat straw obtained after wheat grains are obtained as a raw material with wheat straw according to a liquid ratio of 1:3-1:8, adding KOH to enable the pH value of wheat straw to be 10-14, introducing hot water steam, wherein the hot water steam treatment process lasts for 15-60min, and the steam temperature is 100-; collecting alkali liquor wastewater, and collecting rotten leaves and straws which cannot be processed;

(2) after the hot steam treatment is finished, the wheat straws are subjected to thread rolling and splitting; collecting waste water of the thread rolling section;

(3) reacting the divided wheat straw with an alkaline biological complex enzyme at 40-60 ℃ for 30-90 min; collecting the wastewater generated in the enzyme treatment stage;

(4) grinding the biologically treated wheat straw into pulp.

Treating alkali liquor wastewater, thread rolling section wastewater, wastewater generated in an enzyme treatment stage and pulping washing water by a multi-effect evaporator, evaporating and concentrating to obtain residues, and recovering heat energy for a hot water steam pretreatment section in the step (1); mixing the residues with rotten leaves and straws which cannot be processed in the step (1) to prepare the fertilizer.

2. The method of claim 1, wherein in step (1), the waste wheat straw is cut into 3-6cm long stock for use and air dried.

3. The method of claim 1, wherein in step (1) the pH of the wheat straw reaches 7-9 at the end of the treatment.

4. The method as claimed in claim 1, wherein in the step (2), the thread rolling machine is adopted for physical thread separation, and the process conditions are as follows: the thread rolling compression ratio is controlled to be 1: 1-1: 4.

5. the method as claimed in claim 1, wherein in the step (3), the alkaline biological complex enzyme is a complex enzyme of xylanase, cellulase and pectinase, and the total dosage is as follows: 10-60IU/mL, wherein the enzyme activity ratio of xylanase, cellulase and pectinase is (0-5): (0-4): (0-1.5), and all enzymes are not 0; more preferably (4-3): (2-3): 1.5; preferably, the total dosage of the enzyme is 50-60 IU/mL.

6. The method as claimed in claim 1, wherein in step (4), the number of refining is determined according to production requirements, and the degree of refining is controlled to 25-50 ° SR.

7. The method as set forth in claim 1, wherein in the step (4), the refining process conditions are: and (3) carrying out high-concentration pulping by using a KPF high-concentration disc grinder, wherein the rotating speed of a main shaft is 3000-4000 r/min, one-stage or two-stage pulping is adopted, and the pulping clearance is 0.15-0.5 mm.

8. The method as claimed in claim 1, wherein in the step (4), the mass ratio of the alkali liquor wastewater, the thread rolling section wastewater, the wastewater generated in the enzyme treatment stage and the pulping and washing water is 10-15: 1-3: 20-25: 10-15;

the mass ratio of the residues to rotten leaves and straws which cannot be processed and used in the step (1) is 3-5: 1-2;

the specific process for preparing the fertilizer by acid adjustment comprises the following steps: adding phosphoric acid to adjust pH to 7, drying, pulverizing, and granulating.

9. The bio-mechanical pulp and/or fertilizer prepared by the method of any one of claims 1 to 7.

10. Use of the bio-mechanical pulp of claim 9 for the preparation of paper bags and/or use of fertilizers for promoting crop growth.

Technical Field

The invention belongs to the technical field of papermaking technology and comprehensive utilization of wastes, and particularly relates to a method for preparing true-color biomechanical pulp and byproducts by treating wheat straw with hot steam and biological enzyme.

Background

The information in this background section is only for enhancement of understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art that is already known to a person of ordinary skill in the art.

The paper industry is not only a consumer product industry, but also an important basic raw material industry, and relates to a plurality of fields such as life, culture and education, industry and agriculture, national defense, aviation and the like. In 2016, the import of paper pulp reaches 2106 ten thousand tons and the import of waste paper reaches 2850 ten thousand tons, the import dependence degree of pulping and papermaking fiber raw materials in China is close to 50 percent, and the import of foreign waste paper makes up the gap of the fiber raw materials in China and supports the development of the papermaking industry in China. The 'reform implementation scheme about the banned foreign garbage entry promotion solid waste import management system' is published in the center of 2017 in 4 months, and the waste paper which is not sorted and is banned from import in China is definitely stipulated from 2021. China faces the problem of serious shortage of papermaking raw materials.

In the traditional pulping and papermaking, wheat straw is taken as a representative of grass and is an important papermaking raw material, but because wheat straw leaves, wheat straw sheaths and the like are not easy to pulp, the wheat straw is usually only retained in the material preparation process, the wheat straw leaves and the wheat straw sheaths are required to be removed as far as possible, but the removal of the wheat straw leaves, the wheat straw sheaths and the like not only causes the increase of the material preparation cost, but also greatly reduces the utilization rate of the wheat straw raw material. Therefore, the applicant proposes a preparation process of bio-mechanical pulp by using whole wheat straw waste through heat steam treatment and bio-enzyme treatment, wherein wheat straw waste after wheat is used for obtaining grains is collected together with wheat straw, wheat leaves and leaf sheaths, and the natural color bio-mechanical pulp is prepared through heat steam treatment and bio-enzyme treatment (see CN 109680530A). However, the problem of byproducts generated in the pulping process is not well solved, and the comprehensive high-value utilization of agricultural straws is not facilitated.

Disclosure of Invention

Aiming at the background technology, the invention provides a method for preparing natural-color biomechanical pulp and byproducts by treating wheat straw with hot steam and biological enzyme. The invention provides a method for preparing high-strength natural-color bio-mechanical pulp by using whole wheat straw as a raw material and treating the whole wheat straw by hot water in cooperation with alkaline bio-enzyme, thereby meeting the requirements of producing natural-color packaging paper and paper base materials, recycling byproducts of the natural-color packaging paper and the paper base materials to prepare a biomass compound fertilizer, changing solid wastes into valuables, and realizing high-valued full utilization of the wheat straw. The preparation method is simple, green, clean and efficient, and has good practical application value and wide application prospect.

The specific technical scheme is as follows:

in a first aspect of the present invention, there is provided a method for preparing a bio-mechanical pulp and by-product full-utilization by heat steam treatment in cooperation with bio-enzyme treatment, the method comprising the steps of:

(1) mixing waste wheat straw obtained after wheat grains are obtained as a raw material with wheat straw according to a liquid ratio of 1:3-1:8, adding trace KOH to ensure that the pH value of the wheat straw containing water is 10-14, then introducing hot water steam, wherein the hot water steam treatment process lasts for 15-60min, and the steam temperature is 100-; collecting alkali liquor wastewater, and collecting rotten leaves and straws which cannot be processed;

(2) after the hot steam treatment is finished, the wheat straws are subjected to thread rolling and splitting; collecting waste water of the thread rolling section;

(3) reacting the divided wheat straw with an alkaline biological complex enzyme at 40-60 ℃ for 30-90 min; collecting the wastewater generated in the enzyme treatment stage;

(4) grinding the biologically treated wheat straw into pulp, and collecting pulp grinding washing water;

treating alkali liquor wastewater, thread rolling section wastewater, wastewater generated in an enzyme treatment stage and pulping washing water by a multi-effect evaporator, evaporating and concentrating to obtain residues, and recovering heat energy for a hot water steam pretreatment section in the step (1); mixing the residues with rotten leaves and straws which cannot be processed in the step (1) to prepare the acid fertilizer.

In a second aspect of the invention there is provided a bio-mechanical pulp and/or fertilizer prepared by the above method.

In a third aspect of the invention, there is provided the use of the bio-mechanical pulp in the preparation of paper sack paper and/or the use of fertiliser in promoting the growth of crops.

The beneficial effects of one or more of the above technical solutions are as follows:

according to the technical scheme, wheat grass waste is used as a raw material, and a biological technology and a mechanical method are adopted, so that a good preparation method of the bio-mechanical pulp is developed under the conditions that the papermaking wastewater is ensured to be recycled, the wastewater discharge is not increased, and the environmental pollution is not caused, and the problem of shortage of papermaking fiber raw materials is solved to a great extent. Meanwhile, agricultural residues are utilized with high added value, and can be effectively butted with the problem of three agricultural crops, so that the incineration of crop wastes is stopped from the source, and economic and social benefits are realized.

The invention provides a full utilization technology of wheat harvesting waste for the first time and a new concept of heat steam saturated softening and natural color bio-mechanical pulp for the actual situation that wheat leaves in wheat straws are removed and only wheat straws are utilized in the traditional pulping and papermaking process and for the whole wheat waste (wheat straws, wheat leaves and leaf sheaths); compared with the traditional mechanical pulp, the technology can save the pulping energy by more than 40 percent, and various physical indexes reach the requirements of producing the packing paper and paper base materials. Especially, the natural color packaging paper has wide application.

The technical scheme includes that waste of crop wheat is used as a pulping raw material, wheat straw is treated by normal-pressure hot steam water vapor, simultaneously, a small amount of alkali is added to adjust the pH value of wheat straw water to 10-14, after partial hemicellulose, lignin, pectin and other substances are dissolved out of the wheat straw, the wheat straw is saturated and softened by the hot steam, thread rolling is carried out on a thread rolling machine, the wheat straw raw material is subjected to physical thread separation, then biological enzyme treatment is carried out, after the biological enzyme treatment, fibers are further softened, then the wheat straw is subjected to pulp grinding, and the requirements for producing natural-color packaging paper-like base materials and paper-based materials are met. Especially, the natural color packaging paper has wide application.

According to the technical scheme, waste water generated in each stage is treated by the multi-effect evaporator, solid residues are recovered, meanwhile, the pH value of the waste water is adjusted by trace phosphoric acid, and then the waste water is granulated to prepare the biomass compound fertilizer, wherein the fertilizer contains a proper amount of K, P elements and a large amount of straw components (such as hemicellulose and the like) which are easy to degrade and have small particles, the whole production process is green and environment-friendly, and high-value full utilization of wheat straws is realized. It should be noted that, unlike the conventional preparation of fertilizer based on chemical pulp (chemical pulp requires high temperature and high alkali, generally the temperature is above 160 ℃, and about 20% of alkali consumption) by-product, the technical scheme of the present application adopts a low temperature and less alkali mode, and the straw itself utilized therein is a good material of natural potash fertilizer, so the technical scheme of the present application naturally has "innate advantages" in fertilizer preparation, and meanwhile, through optimizing the screening process conditions, the biomass compound fertilizer prepared by the present application also has the advantages of high fertilizer efficiency, good storage stability and the like.

In conclusion, the preparation method of the technical scheme is simple, energy-saving and environment-friendly, accords with the industrial policies of national resource conservation, economic cycle, energy conservation and emission reduction, and can generate good social benefit, economic benefit and ecological benefit, thereby having good practical application value and industrial application prospect.

Detailed Description

It is to be understood that the following detailed description is exemplary and is intended to provide further explanation of the invention as claimed. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of the stated features, steps, operations, and/or combinations thereof, unless the context clearly indicates otherwise.

In the invention, the liquid ratio refers to the cooking liquid ratio of the raw materials, and the liquid ratio is as follows: the ratio of the weight of the cooked oven dried raw material to the volume of the total cooked liquor.

In a first exemplary embodiment of the present invention, there is provided a method for preparing a bio-mechanical pulp and by-product full-utilization by heat steam treatment in cooperation with bio-enzyme treatment, the method comprising the steps of:

(1) mixing waste wheat straw obtained after wheat grains are obtained as a raw material with wheat straw according to a liquid ratio of 1:3-1:8, adding trace KOH to ensure that the pH value of the wheat straw containing water is 10-14, then introducing hot water steam, wherein the hot water steam treatment process lasts for 15-60min, and the steam temperature is 100-; collecting alkali liquor wastewater, and collecting rotten leaves and straws which cannot be processed;

(2) after the hot steam treatment is finished, the wheat straws are subjected to thread rolling and splitting; collecting waste water of the thread rolling section;

(3) reacting the divided wheat straw with an alkaline biological complex enzyme at 40-60 ℃ for 30-90 min; collecting the wastewater generated in the enzyme treatment stage;

(4) grinding the biologically treated wheat straw into pulp, and collecting pulp grinding washing water;

treating the waste water of the thread rolling section, the waste water generated in the enzyme treatment stage and the pulping washing water by a multi-effect evaporator, evaporating and concentrating to obtain residues, and recovering heat energy for the hot water steam pretreatment section in the step (1); mixing the residues with rotten leaves and straws which cannot be processed in the step (1) to prepare the fertilizer.

In the step (1), the waste wheat straw is cut into standby raw materials with the length of 3-6cm, and the raw materials are air-dried.

In the step (1), the liquid ratio is 1:3-1:8(g/mL), and through a large amount of experimental verification and analysis, the solution with the liquid ratio forms a wheat straw solution with a specific pH after a certain time, so that the pH of the prepared biomechanical slurry is neutral.

In the step (1), the wheat straw is subjected to specific treatment by using hot steam, so that the fiber of the wheat straw is softer, and through experimental verification, compared with other methods, the paper bag paper with better comprehensive strength can be prepared, and the cost of the natural color packaging paper is greatly reduced. In the step (1), KOH is added, the pH value of wheat straw water is adjusted to 10-14, and the purpose of adding KOH is as follows: on one hand, a small part of substances such as hemicellulose, lignin, pectin and the like can be dissolved out from wheat straw, and on the other hand, the wheat straw is softened as quickly as possible by auxiliary hot steam, so that the wheat straw is used as a basis for next-step thread rolling and splitting; more importantly, potassium is a necessary major element of plants, so that the fertilizer prepared subsequently is rich in potassium elements by using potash treatment.

In the step (1), the temperature of the heat steam treatment is 100-120 ℃, and the time is 15-60 min. Tests prove that if the temperature is too low, the whole wheat straw waste cannot be effectively softened by absorbing water, and the subsequent filament separating effect is influenced.

In the step (2), a TSP360 thread rolling machine is adopted for thread rolling and thread separation, and the process conditions are as follows: the thread rolling compression ratio is controlled to be 1: 1-1: 4.

the processing method has the advantages that the wheat straws after being saturated with water and softened are processed by the thread rolling machine, so that the wheat straws can achieve a good thread separating effect, and the grinding efficiency can be obviously improved. More importantly, the inventor finds that compared with the process of screw extrusion spinning, the spinning splitting effect is better when a thread rolling machine is used for splitting threads, the extruding and shearing effects are weaker, the damage to wheat straw fibers is smaller, and the finally obtained paper has better tensile property.

In the step (3), the liquid ratio is controlled to be 1: 3-8 (g/mL).

Aiming at the specific wheat straw waste raw material after extrusion, the selected alkaline biological compound enzyme is a compound enzyme of xylanase, cellulase and pectinase, and the total dosage is as follows: 10-60IU/mL, wherein the enzyme activity ratio of xylanase, cellulase and pectinase is (0-5): (0-4): (0-1.5), and all enzymes are not 0; more preferably (3-4): (2-3): 1.5; preferably, the total dosage of the enzyme is 50-55 IU/mL. The applicant further researches and discovers that the fertilizer efficiency and the storage stability of the fertilizer can be effectively improved by optimizing the enzyme activity ratio of the biological compound enzyme and matching with the subsequent addition amount of each wastewater while ensuring the high performance of the formed slurry.

In the step (4), the pulping times are determined according to production requirements, and the pulping degree is controlled to be 25-50 DEG SR.

The pulping process conditions are as follows: and (3) carrying out high-concentration pulping by using a KPF high-concentration disc grinder, wherein the rotating speed of a main shaft is 3000-4000 r/min, one-stage or two-stage pulping is adopted, and the pulping clearance is 0.15-0.5 mm.

Wherein the mass ratio of the alkali liquor wastewater, the thread rolling section wastewater, the wastewater generated in the enzyme treatment stage and the pulping and washing water is 10-15: 1-3: 20-25: 10-15;

the mass ratio of the residues to rotten leaves and straws which cannot be processed in the step (1) is 3-5: 1-2.

The specific process for preparing the fertilizer by acid adjustment comprises the following steps: adding phosphoric acid to adjust pH to 7, drying, pulverizing, and granulating. By adopting phosphoric acid treatment, the alkaline is neutralized, and meanwhile, nutrient elements such as phosphorus and the like are introduced, so that the method is more economic and environment-friendly.

In a second exemplary embodiment of the invention, a biomechanical slurry and/or fertilizer produced using the above method is provided. The fibers in the bio-mechanical pulp are staggered uniformly, soft, long and uniform in fiber length. Subsequent experiments prove that the paper base material prepared from the bio-mechanical pulp has higher bursting index, tearing index and ring crush index, and is suitable for preparing natural color packaging paper bags. Meanwhile, the fertilizer prepared by the invention is a biomass compound fertilizer, and tests prove that the fertilizer has better fertilizer efficiency and storage stability.

In a third exemplary embodiment of the invention, the use of the bio-mechanical pulp for the preparation of paper bags and/or the use of fertilizers for promoting the growth of crops is provided.

In order to make the technical solutions of the present invention more clearly understood by those skilled in the art, the technical solutions of the present invention will be described in detail below with reference to specific embodiments.

Example 1: a heat steam treatment cooperates with the preparation method that the biological mechanical pulp and by-product of the biological enzyme treatment are utilized completely, this example prepares the biological mechanical pulp of wheat straw true qualities; and simultaneously preparing the biomass compound fertilizer.

(1) Cutting the physically selected and dedusted air-dried wheat straw into 5 cm-long standby raw materials, putting the raw materials into a wheat straw processor or a reaction kettle, mixing the wheat straw according to a liquid ratio of 1:5(g/mL), adding a trace amount of alkali KOH into the mixture, and adjusting the pH value of the wheat straw water to be 14; rotten leaves and straws which cannot be processed are collected;

(2) introducing hot water vapor at 110 deg.C for 20min to dissolve out small part of hemicellulose, lignin and pectin from wheat straw, softening wheat straw with hot saturated water, and collecting alkaline solution wastewater when the pH value of softened wheat straw is 8;

(3) carrying out thread rolling on a wheat straw TSP360 thread rolling machine which is softened by hot steam and hot saturation, and adjusting the pressure of the thread rolling machine to enable the wheat straw to achieve a uniform and good thread dividing effect; collecting waste water of the thread rolling section;

the thread rolling process conditions are as follows: pressure during thread rolling 1: 3.

(4) processing the softened and devillicated wheat straw and alkaline biological enzyme in a biological processor or a biological reactor for 50min, controlling the temperature at 50 ℃ and the liquid ratio at 1:6(g/mL), and continuously stirring and mixing the wheat straw to enable the wheat straw and the biological enzyme to fully act so as to further soften wheat straw fibers.

The alkaline biological compound enzyme is a compound enzyme of xylanase, cellulase and pectinase, the total dosage is 50IU/mL (50 IU biological enzyme is adopted in 1mL feed liquid), and the enzyme activity ratio of the xylanase, the cellulase and the pectinase is 4: 2: 1.5; collecting the wastewater generated in the enzyme treatment stage;

(5) the bio-treated wheat straw is ground into pulp by a pulping machine for two sections, so that the pulp beating degree reaches 42 DEG SR.

The technological parameters of the pulp grinding are as follows: carrying out high-concentration pulp grinding by using a KPF high-concentration disc grinder, wherein the rotating speed of a main shaft is 3000r/min, and the pulp grinding gap is 0.3 mm; collecting the milling washing water;

(6) defibering the grinded wheat straw bio-mechanical pulp by a defibering device to be uniformly mixed, and then making the mixture into paper on a paper formerType 60g/m²The natural color paper for paper bags. All physical indexes meet the requirements of producing natural-color packing paper and paper base materials.

Mixing alkali liquor wastewater, thread rolling section wastewater, wastewater generated in an enzyme treatment stage and pulping washing water according to a mass ratio of 10:3:20:10, then carrying out evaporation concentration, adopting a multi-effect evaporator to treat evaporation concentration to obtain residues, and recovering heat energy for a hot water steam pretreatment section in the step (1); mixing the residues with rotten leaves and straws which cannot be processed and used in the step (1) according to a ratio of 4:1, adding phosphoric acid to adjust the pH value to 7, drying, crushing and granulating to prepare the biomass organic fertilizer.

Example 2: a heat steam treatment cooperates with the preparation method that the biological mechanical pulp and by-product of the biological enzyme treatment are utilized completely, this example prepares the biological mechanical pulp of wheat straw true qualities; and simultaneously preparing the biomass compound fertilizer.

(1) Cutting the physically selected and dedusted air-dried wheat straw into 4 cm-long standby raw materials, putting the raw materials into a wheat straw processor or a reaction kettle, mixing the wheat straw according to a liquid ratio of 1:4(g/mL), adding a trace amount of alkali KOH into the mixture, and adjusting the pH value of the wheat straw water to be 14; collecting rotten leaves and straws which can not be processed.

(2) Introducing hot water vapor at 100 deg.C for 30min to dissolve out small part of hemicellulose, lignin and pectin from wheat straw, softening wheat straw with hot saturated water, and collecting alkaline solution wastewater when the pH value of softened wheat straw is 9.

(3) Carrying out thread rolling on the wheat straws softened by hot saturated water on a TSP360 thread rolling machine, adjusting the pressure of the thread rolling machine to enable the wheat straws to achieve a uniform and good thread dividing effect, and collecting waste water of a thread rolling section;

the thread rolling process conditions are as follows: the thread rolling compression ratio is controlled to be 1: 4.

(4) processing the softened and thread-rolled wheat straw and alkaline biological enzyme in a biological processor or a biological reactor for 60min, controlling the temperature at 55 ℃ and the liquid ratio at 1:5(g/mL), and continuously stirring and mixing the wheat straw to enable the wheat straw and the biological complex enzyme to fully act so as to further soften wheat straw fibers.

The alkaline biological compound enzyme is a compound enzyme of xylanase, cellulase and pectinase, the total dosage is 60IU/mL, and the enzyme activity ratio of the xylanase, the cellulase and the pectinase is 4: 3: 1.5; collecting the wastewater generated in the enzyme treatment stage;

(5) and (3) pulping the biologically treated wheat straw by using a pulping machine to ensure that the pulp beating degree reaches 45 DEG SR.

The technological parameters of the pulping are as follows: carrying out high-concentration pulping by using a KPF high-concentration disc grinder, wherein the rotating speed of a main shaft is 3000r/min, two-stage pulping is adopted, and the pulping clearance is 0.2 mm; collecting the milling washing water;

(6) defibering the grinded wheat straw bio-mechanical pulp by a defibering device to uniformly mix the wheat straw bio-mechanical pulp, and then making and forming 80g/m on a paper forming device²The natural color paper for paper bags. Then, the physical strength was measured. All physical indexes meet the requirements of producing natural-color packing paper and paper base materials.

Mixing alkali liquor wastewater, thread rolling section wastewater, wastewater generated in an enzyme treatment stage and pulping washing water according to a mass ratio of 15:1:20:15, then carrying out evaporation concentration, adopting a multi-effect evaporator to treat evaporation concentration to obtain residues, and recovering heat energy for a hot water steam pretreatment section in the step (1); mixing the residues with rotten leaves and straws which cannot be processed and used in the step (1) according to a ratio of 5:2, adding phosphoric acid to adjust the pH value to 7, drying, crushing and granulating to prepare the biomass organic fertilizer.

Example 3: the embodiment of the method for preparing the natural-color bio-mechanical pulp of the wheat straw and simultaneously preparing the biomass compound fertilizer.

(1) Cutting the physically selected and dedusted air-dried wheat straws into 6 cm-long standby raw materials, putting the raw materials into a wheat straw processor or a reaction kettle, mixing the wheat straws according to a liquid ratio of 1:6(g/mL), adding a trace amount of alkali KOH into the mixture, adjusting the pH value of the wheat straws containing water to be 13, and collecting rotten leaves and straws which cannot be processed and used;

(2) introducing hot water vapor at 110 deg.C for 20min to dissolve out small part of hemicellulose, lignin and pectin from wheat straw, softening wheat straw with hot saturated water, and collecting alkaline solution wastewater when the pH value of softened wheat straw is 8.

(3) The wheat straw which is saturated and softened by hot steam is subjected to thread rolling on a TSP360 thread rolling machine, and the pressure of the thread rolling machine is adjusted to ensure that the wheat straw achieves a uniform and good thread dividing effect; collecting waste water of the thread rolling section;

the thread rolling process conditions are as follows: thread rolling pressure 1: 3.

(4) processing the softened and devillicated wheat straw and alkaline biological enzyme in a biological processor or a biological reactor for 90min, controlling the temperature at 50 ℃ and the liquid ratio at 1:5(g/mL), continuously stirring and mixing the wheat straw to enable the wheat straw and the biological enzyme to fully act, and further softening wheat straw fibers.

The alkaline biological compound enzyme is a compound enzyme of xylanase, cellulase and pectinase, the total dosage is 50IU/mL, and the enzyme activity ratio of the xylanase, the cellulase and the pectinase is 3: 3: 1.5, collecting the wastewater generated in the enzyme treatment stage;

(5) and (3) pulping the biologically treated wheat straws by using a pulping machine to ensure that the pulp beating degree reaches 38 DEG SR.

The technological parameters of the pulping are as follows: carrying out high-concentration grinding by using a KPF high-concentration disc grinder, wherein the rotating speed of a main shaft is 3000r/min, and a section of grinding is adopted, and the grinding gap is 0.25 mm; collecting the milling washing water;

(6) defibering the grinded wheat straw bio-mechanical pulp by a defibering device to uniformly mix the wheat straw bio-mechanical pulp, and then making and forming the wheat straw bio-mechanical pulp with 60g/m on a paper forming device²The natural color paper for paper bags. All physical indexes meet the requirements of producing natural-color packing paper and paper base materials.

Mixing alkali liquor wastewater, thread rolling section wastewater, wastewater generated in an enzyme treatment stage and pulping washing water according to the mass ratio of 12:2:25:15, then carrying out evaporation concentration, carrying out hair-increasing concentration, carrying out evaporation concentration by adopting a multi-effect evaporator to obtain residues, and recovering heat energy for a hot water steam pretreatment section in the step (1); mixing the residues with rotten leaves and straws which cannot be processed and used in the step (1) according to a ratio of 3:1, adding phosphoric acid to adjust the pH value to 7, drying, crushing and granulating to prepare the biomass organic fertilizer.

Experimental example 1: the method is the same as the example 1, and is characterized in that the biological enzyme after the thread rolling on the TSP360 thread rolling machine is adjusted to be the compound enzyme using three enzymes of xylanase, cellulase and pectinase, the total dosage is 50IU/mL, the enzyme activity ratio is 2:2: 1.5.

experimental example 2: the method is the same as the example 1, and is characterized in that the biological enzyme after the thread rolling on the TSP360 thread rolling machine is adjusted to be the compound enzyme using three enzymes of xylanase, cellulase and pectinase, the total dosage is 50IU/mL, the enzyme activity ratio is 5: 4: 1.5.

experimental example 3: the method is the same as the example 1, and is characterized in that the mass ratio of the alkali liquor wastewater, the thread rolling section wastewater, the wastewater generated in the enzyme treatment stage and the pulping and washing water is controlled to be 5:2:5: 10.

Experimental example 4: the method is the same as the example 1, and is characterized in that the mass ratio of the alkali liquor wastewater, the thread rolling section wastewater, the wastewater generated in the enzyme treatment stage and the pulping and washing water is controlled to be 10:1:5: 5.

Experimental example 5: the method is the same as example 1, except that the mass ratio of the residue to rotten leaves and straws which cannot be processed in step (1) is controlled to 1: 1.

Experimental example 6: the method is the same as the example 1, and is characterized in that the mass ratio of the residues to rotten leaves and straws which cannot be processed in the step (1) is controlled to be 6: 1.

Effect verification：

1. Table 1 shows a comparison of the physical properties of the pulps prepared in example 1 and experimental examples 1 and 2, and it can be seen that the physical properties of the respective constituent pulps are better, and the requirements for producing natural-color wrapping paper and paper-based materials are met. Examples 3-6 the physical properties of the resulting slurry were the same as those of example 1.

TABLE 1 comparison list of physical performance indexes of pulp formed by using wheat straw hot steam and bio-enzyme treatment

2. Example 1 and Experimental examples 1-6 detection of fertilizer efficiency of biomass compound fertilizer

(1) Corn pot test

The results of the experiment in which the biomass compound fertilizer prepared in example 1 and experimental examples 1 to 6 was applied to potted corn and the biomass compound fertilizer (3g/kg soil) was applied to the seedling stage of corn are shown in table 2, which indicates that the biomass of corn was significantly increased in both example 1 and experimental examples 1 to 6 as compared to the control group CK without fertilizer application, wherein the effect was the best in example 1.

TABLE 2

(2) Wheat potting test

The results of experiments in which the biomass compound fertilizers prepared in examples 1 and 1 to 6 were applied to potted wheat and the biomass compound fertilizers (5g/kg soil) were applied to the seedling stage of the wheat are shown in table 3, which indicates that both examples 1 and 1 to 6 increase the biomass of the wheat as compared with the control group CK without fertilization, wherein the effect is the best in example 1.

TABLE 3

Examples of the invention	Biomass (g/basin)	Increase (%)
			CK	10.78	-
Example 1	13.51	25.3
			Experimental example 1	11.96	10.9
Experimental example 2	12.43	13.3
			Experimental example 3	12.14	12.6
Experimental example 4	11.85	10.0
			Experimental example 5	12.01	11.4
Experimental example 6	12.89	19.6

3. Example 1, Experimental examples 1-6 detection of storage stability of Biomass Compound fertilizers

The caking problem affects the appearance quality of the compound fertilizer and brings inconvenience to the transportation and application of the compound fertilizer, so that the storage stability (anti-caking performance) of the prepared biomass compound fertilizer is tested by a briquetting method, 50g of compound fertilizer samples are filled in a circular ring under the conditions of 50 ℃ of temperature, 147N of pressure and 15 days, and the test result is shown in table 4. As can be seen, the storage stability of the biomass compound fertilizer prepared by the method is far higher than that of the biomass compound fertilizer prepared by the experimental examples 1-6.

TABLE 4

Examples of the invention	Shear force (N)	Blocking prevention Rate (%)
			Example 1	30.82	59.1
Experimental example 1	45.96	39.0
			Experimental example 2	49.75	34.0
Experimental example 3	51.27	31.9
			Experimental example 4	48.29	35.9
Experimental example 5	61.56	18.3
			Experimental example 6	59.86	20.5

Note: the blocking resistance was (blank shear force-sample shear force)/blank shear force × 100%, and the blank shear force was 75.34N.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.