JP2024519526A - Bioenzymatic pretreatment to control the physical and chemical properties of wheat grass waste granular fuel - Google Patents

Abstract

The present invention relates to a method for adjusting the physical and chemical properties of wheat grass waste granular fuel by biological enzyme pretreatment, which belongs to the field of bio-based material production. The method includes carrying out biological enzyme pretreatment on wheat grass waste, drying, obtaining enzyme pretreated wheat grass waste, uniformly mixing the enzyme pretreated wheat grass waste with pulp production wastewater, and heating and extruding the mixture to obtain. The method of the present invention is simple, convenient to operate, highly practical, and environmentally friendly, and can improve the physical and chemical properties of wheat grass waste granular fuel, and solve the problem of the current difficulty in utilizing solid waste and wastewater in high value during pulp production. [Selected Figure] Figure 1

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to a Chinese patent application filed with the China Patent Office on April 11, 2022, with application number CN202210373029.9, entitled "Method for Pretreatment Adjustment of the Physical and Chemical Performance of Wheat Grass Waste Granule Fuel by Biological Enzymes", the entire contents of which are incorporated herein by reference.
The present invention is in the field of bio-based material production, specifically, a method for bioenzymatic pretreatment modulation of the physical and chemical properties of wheat grass waste granule fuel.

At the key moment of global energy transformation, agricultural waste fiber raw materials as a sustainable green clean energy have become the focus of researchers' attention as a sustainable renewable clean energy. Wheat grass reserves are huge, but the utilization rate is low, and there is great potential for development and utilization. Wheat grass is one of the fiber raw materials for the pulping and papermaking industry, but the pulp production of wheat grass generates some waste and waste liquid during the whole process from material preparation to pulp, mainly including wheat grass waste generated in the material preparation stage and waste liquid generated in the pretreatment and grinding process. After the solid waste is collected, a large amount of space is occupied, and the waste liquid generated during pretreatment and pulp production contains a large amount of dissolved organic matter, all of which become the pollutant load of pulping and papermaking enterprises. By making full use of the material of this part and processing it into biomass granular fuel for production, it can effectively improve the problem of the accumulation of solid waste and the difficulty of treating waste liquid in paper factories. Therefore, how to effectively use these waste materials and wastewater and convert them into high-value-added bioenergy products is one of the technical bottlenecks that the current grass biomass fiber feedstock needs to resolve for papermaking.

To solve the above problems, the present invention provides a method for producing granular fuel using solid residues generated during the biochemical-mechanical pulping of wheat grass, which have been pretreated by biological enzyme regulation, and waste liquid generated during the pulp production. Wheat grass waste is first pretreated and conditioned with biological enzymes, and then mixed with waste liquids generated at each stage during the pulp production of wheat grass in a certain mass ratio and heated to better bind and mold the mixture into granular fuel.

To achieve the above technical objectives, the present invention employs the following technical solutions:

The first aspect of the present invention is a method for producing a cellular membrane comprising the steps of:
The wheat grass waste is subjected to biological enzyme pretreatment and dried to obtain enzyme pretreated wheat grass waste.
The enzyme-pretreated wheat grass waste and pulp manufacturing waste liquid are uniformly mixed, heated, extruded and molded to obtain wheat grass waste granular fuel. A method for pretreating and adjusting the physical and chemical properties of wheat grass waste granular fuel using a biological enzyme is also provided.

The present invention uses biological enzymes to pre-treat and adjust the performance of solid waste and effluent generated during the chemical-mechanical pulping of wheat grass to produce low-cost, environmentally friendly granular fuel.

A second aspect of the present invention provides wheat grass waste granular fuel produced by any one of the above methods.

A third aspect of the present invention provides a use of the wheat grass waste granular fuel in the field of clean energy.

The beneficial effects of the present invention are as follows:
(1) The solid waste wheat grass waste and waste liquid generated during the biochemical-mechanical pulping of wheat grass used in the present invention have the advantage of high added value utilization of waste.
(2) The granular fuel of the present invention mainly contains three elements: C, H, and O, and the gas produced by combustion is mainly _CO2 , which is a clean product.
(3) The biological enzymes used in the pretreatment of the present invention are non-toxic, tasteless, and environmentally friendly.
(4) The manufacturing method of the present invention is simple and practical, and has good economic and environmental advantages.

The accompanying drawings, which form a part of the present invention, are used to provide a further understanding of the present invention, and the exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute undue limitations of the present invention.
FIG. 2 is a physical diagram/sample appearance diagram of wheat grass waste granular fuel produced in each Example and Comparative Example of the present invention.

Please note that the following detailed description is all exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those skilled in the art.

The first object of the present invention is to solve the problem of recycling solid waste and waste liquid during the biochemical-mechanical pulping of wheat grass.

A second object of the present invention is to provide a method for adjusting wheat grass waste granule fuel performance by pretreatment with biological enzymes.

The third object of the present invention is to provide a method for producing granular fuel using waste and waste liquor from wheat grass pulp production.

To this end, the present invention provides a method for the production of a bioenzyme-regulated wheat grass waste/pulp mill effluent-based granular fuel, specifically comprising:
The process involves bioenzyme pretreatment of wheat grass waste generated during the preparation of wheat grass material in factories, and then mixing it with pulp waste liquor in a specific ratio, stirring uniformly, and heating and extruding it to obtain granular fuel.

In some embodiments, the wheat grass waste is larger than 60 mesh (0.22 mm) after passing through a 60 mesh standard sieve;
In some embodiments, the enzymes include lipase, xylanase, and cellulase.

In some embodiments, the waste liquor from the pulp manufacturing process is black liquor.

In some embodiments, the enzyme pretreatment is to sieve the wheat grass waste through a 60 mesh sieve to obtain wheat grass waste with a particle size larger than 0.22 mm, prepare it for use by drying it under 105°C conditions for 4 h, prepare a buffer solution with a pH of 5.0, control the pretreatment temperature at 50°C, add 0.05 g (0.50 wt% of the solid waste content) of lipase/xylanase/cellulase to treat, stir for 10 min, then add 10 g of wheat grass waste and mix, stir for 6 h, and put the lipase/xylanase/cellulase treated wheat grass waste into a 60°C oven to dry it for use.

In some embodiments, the specific steps of producing the granular fuel are to add a certain amount of waste liquid to the wheat grass waste after the enzyme pretreatment, mix uniformly, and dry so that the mass ratio of the wheat grass waste is 74.0%, the mass ratio of solids in the waste liquid is 24.0%, and the mass ratio of water in the mixture is 2.0%. 1.0 g of the mixture is added into a molding die sleeve, and compression molded in a hydraulic press under conditions of a pressure of 6 MPa and a temperature of 100°C, and its density, heat value, and mechanical properties are measured. Here, both the polysaccharides and lignin contained in the pulp waste liquid have specific adhesive properties that can be used as binders, and can also improve combustion performance.

In some embodiments, the granular fuel is compressed and molded via a hydraulic press.

The present invention will now be described in more detail with reference to specific examples. Please note that the specific examples are for illustrative purposes only and do not limit the present invention.

All of the black liquor in the following examples and comparative examples is pulp black liquor taken from a paper mill.

Comparative Example 1
Granular fuel preparation and performance measurement: Wheat grass waste with a particle size of 0.22 mm or less was sieved through a 60-mesh screen and dried at 105°C for 4 hours, then 10.0 wt% deionized water was added and mixed and stirred uniformly, and 1.0 g of the thoroughly and uniformly mixed wheat grass waste was placed in a molding die sleeve and compressed under a hydraulic press pressure of 6 MPa at room temperature. The density was measured, and the heat value of the biomass granular fuel was measured by a calorimeter, and its horizontal compression strength was measured by a universal testing machine.

Comparative Example 2
Granular fuel production and performance measurement: Wheat grass waste with a particle size of 0.22 mm or more left after sieving through a 60-mesh sieve was dried at 105°C for 4 hours, then 10.0 wt% deionized water was added and mixed and stirred uniformly, and 1.0 g of the thoroughly and uniformly mixed wheat grass waste was placed in a molding die sleeve and compressed at room temperature under a hydraulic press pressure of 6 MPa. The density was measured, and the heat value of the granular fuel was measured by a calorimeter, and the horizontal compression strength was measured by a universal testing machine.

Comparative Example 3
Granular fuel production and performance measurement: Wheat grass waste with a particle size of 0.22 mm or more left after sieving through a 60-mesh sieve was dried under the condition of 105°C for 4 hours, then a certain amount of black liquor was added and mixed uniformly, and dried to make the mass ratio of the wheat grass waste 74.0%, the mass ratio of solid matter in the waste liquor 24.0%, and the mass ratio of water in the mixture 2.0%, and 1.0 g of the dried wheat grass waste/waste liquor mixture was placed in a molding die sleeve and compressed under a hydraulic press pressure of 6 MPa at room temperature. The density was measured, and the heat value of the granular fuel was measured by a calorimeter, and its horizontal compressive strength was measured by a universal testing machine.

Example 1
(1) Bioenzyme treatment of granular fuel: Wheat grass waste with a particle size of 0.22 mm or more was left through a 60-mesh sieve and dried at 105°C for 4 hours in preparation for use. A buffer solution of pH 5.0 was prepared, the pretreatment temperature was controlled at 50°C, 0.05 g (accounting for 0.50% of the solid waste content) of xylanase was added for treatment, and stirred for 10 min. Then, 10 g of wheat grass waste was added and mixed, and stirred for 6 hours. The wheat grass waste pretreated with xylanase was placed in an oven at 60°C and dried in preparation for use.
(2) Production of granular fuel and measurement of its performance: A certain amount of black liquor was added to the above-mentioned xylanase-treated wheat grass waste, mixed uniformly, and dried, in which the mass ratio of the wheat grass waste was 74.0%, the mass ratio of solid matter in the waste liquor was 24.0%, and the mass ratio of water in the mixture was 2.0%. 1.0 g of the dried wheat grass waste/waste liquor mixture was placed in a molding die sleeve and compression molded under the conditions of a hydraulic press pressure of 6 MPa and a temperature of 100° C. The density of the granular fuel was measured, the heat value of the granular fuel was measured by a calorimeter, and its horizontal compressive strength was measured by a universal testing machine.

Example 2
(1) Enzyme treatment of granular fuel: wheat grass waste with a particle size of 0.22 mm or more was left through a 60-mesh sieve and dried at 105°C for 4 hours in preparation for use. A buffer solution of pH 5.0 was prepared, the pretreatment temperature was controlled at 50°C, 0.05 g (accounting for 0.50% of the solid waste content) of lipase was added for treatment, and stirred for 10 min. Then, 10 g of wheat grass waste was added and mixed, and stirred for 6 hours. The lipase-treated wheat grass waste was then placed in a 60°C oven and dried in preparation for use.
(2) Production of granular fuel and measurement of its performance: A certain amount of black liquor was added to the above-mentioned lipase-treated wheat grass waste, mixed uniformly, and dried, in which the mass ratio of the wheat grass waste was 74.0%, the mass ratio of solid matter in the waste liquor was 24.0%, and the mass ratio of water in the mixture was 2.0%. 1.0 g of the dried wheat grass waste/waste liquor mixture was placed in a molding die sleeve and compression molded under the conditions of a hydraulic press pressure of 6 MPa and a temperature of 100° C. The density of the granular fuel was measured, the heat value of the granular fuel was measured by a calorimeter, and its horizontal compression strength was measured by a universal testing machine.

Example 3
(1) Enzyme treatment of granular fuel: Wheat grass waste with a particle size of 0.22 mm or more was left after sieving through a 60-mesh sieve and dried at 105°C for 4 hours in preparation for use. A buffer solution of pH 5.0 was prepared, the temperature of the water bath was controlled at 50°C, 0.05 g (accounting for 0.50% of the solid waste content) of cellulase was added for treatment, and stirred for 10 min. Then, 10 g of wheat grass waste was added and mixed, and stirred for 6 hours. The wheat grass waste treated with cellulase was then placed in an oven at 60°C and dried in preparation for use.
(2) Production of granular fuel and measurement of its performance: A certain amount of black liquor was added to the above-mentioned cellulase-treated wheat grass waste, mixed uniformly, and dried to make the mass of the wheat grass waste 74.0%, the mass of solids in the waste liquid 24.0%, and the mass of water in the mixture 2.0%, and 1.0 g of the dried wheat grass waste/waste liquid mixture was placed in a molding die sleeve and compression molded under conditions of a hydraulic press pressure of 6 MPa and a temperature of 100° C. The density of the granular fuel was measured, the heat value of the granular fuel was measured by a calorimeter, and its horizontal compressive strength was measured by a universal testing machine.

Example 4
(1) Enzyme treatment of granular fuel: The wheat grass waste with a particle size of 0.22 mm or more that was left after sieving through a 60-mesh sieve was dried under conditions of 105°C for 4 hours in preparation for use, a buffer solution of pH 5.0 was prepared, the pretreatment temperature was controlled at 50°C, 0.05 g (accounting for 0.50% of the solid waste content) of xylanase/cellulase was added for treatment, and stirred for 10 min, then 10 g of wheat grass waste was added and mixed, and stirred for 6 hours, and the wheat grass waste treated with xylanase/cellulase was placed in an oven at 60°C and dried in preparation for use.
(2) Production of granular fuel and measurement of its performance: A certain amount of black liquor was added to the wheat grass waste treated with the xylanase/cellulase, mixed uniformly, and dried to make the mass ratio of the wheat grass waste 74.0%, the mass ratio of solids in the waste liquid 24.0%, and the mass ratio of water in the mixture 2.0%, and 1.0 g of the dried wheat grass waste/waste liquid mixture was placed in a molding die sleeve and compression molded under hydraulic press pressure of 6 MPa and temperature of 100° C. The density of the granular fuel was measured, the heat value of the granular fuel was measured by a calorimeter, and its horizontal compressive strength was measured by a universal testing machine.

Example 5
(1) Enzyme treatment of granular fuel: The wheat grass waste with a particle size of 0.22 mm or more that was left after sieving through a 60-mesh sieve was dried under the condition of 105°C for 4 hours in preparation for use, a buffer solution of pH 5.0 was prepared, the pretreatment temperature was controlled at 50°C, 0.05 g (accounting for 0.50% of the solid waste content) of lipase/xylanase/cellulase was added for treatment, and stirred for 10 min, then 10 g of wheat grass waste was added and mixed, and stirred for 6 hours, and the wheat grass waste treated with lipase/xylanase/cellulase was placed in a 60°C oven and dried in preparation for use.
(2) Production of granular fuel and measurement of its performance: A certain amount of black liquor was added to the wheat grass waste treated with the lipase/xylanase/cellulase, mixed uniformly, and dried to make the mass ratio of the wheat grass waste 74.0%, the mass ratio of solids in the waste liquid 24.0%, and the mass ratio of water in the mixture 2.0%, and 1.0 g of the dried wheat grass waste/waste liquid mixture was placed in a molding die sleeve and compression molded under conditions of a hydraulic press pressure of 6 MPa and a temperature of 100° C. The density of the granular fuel was measured, the heat value of the granular fuel was measured by a calorimeter, and its horizontal compressive strength was measured by a universal testing machine.

Raw material analysis:
The measurement method was to measure the cellulose, hemicellulose, and acid-insoluble lignin contents in the wheat grass waste according to the NREL method, measure the elemental composition analysis by an automatic element analyzer, calculate the lignin content in the pulp waste liquor by measuring the absorbance by an ultraviolet spectrophotometer, and measure the sugar component content by an ICS5000+ ion chromatograph. The measurement results are shown in Tables 1 and 2.

Table 1 Chemical and elemental composition analysis (%) of waste prepared from wheat grass material

Table 2 Analysis of black liquor components and contents

Table 3. Physical and chemical performance analysis of biomass granular fuel

Finally, please note that the above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, for those skilled in the art, they can still modify the technical solutions described in the above embodiments, or replace parts of them with equivalents. Any modifications, equivalent replacements, improvements, etc. in the spirit and principle of the present invention shall all be included in the protection scope of the present invention.

Claims (14)

The method for adjusting the physical and chemical properties of wheat grass waste granule fuel by bioenzymatic pretreatment is as follows:
The wheat grass waste is subjected to biological enzyme pretreatment and dried to obtain enzyme pretreated wheat grass waste.
The method for adjusting the physical and chemical properties of wheat grass waste granular fuel by pretreatment with biological enzymes includes uniformly mixing the wheat grass waste and pulp manufacturing waste liquid after the enzyme pretreatment, and heating and extruding the mixture to obtain wheat grass waste granular fuel. drying and preparing the wheat grass waste for use;
2. The method according to claim 1, further comprising the steps of: adding an enzyme to a buffer solution, followed by adding the dried grass waste and mixing and stirring to obtain an enzyme-treated grass waste. The method according to claim 1 or 2, characterized in that the enzyme used in the biological enzyme pretreatment is at least one of lipase, xylanase, and cellulase. The method according to claim 3, characterized in that the enzymes used in the biological enzyme pretreatment are lipase, xylanase and cellulase. The method according to claim 1 or 2, characterized in that the conditions used in the biological enzyme pretreatment are a pretreatment temperature of 50 to 60°C, a pretreatment buffer solution pH of 5.0 to 5.5, and a pretreatment time of 6 to 8 hours. The method according to claim 1 or 2, characterized in that the mass of the biological enzyme is 0.50 to 0.80 wt % of the mass of the wheat grass waste. The method according to claim 1 or 2, characterized in that the grain size of the wheat grass waste is greater than 0.22 mm. The biological enzyme pretreatment is
Sieving the wheat grass waste through a 60 mesh sieve to obtain wheat grass waste with a particle size of more than 0.22 mm, and drying it under 105° C. for 4 h to prepare it for use;
The method according to claim 2, comprising the steps of: preparing a buffer solution of pH 5.0; controlling the pretreatment temperature at 50°C; adding biological enzymes of 0.50 wt% of the solid waste content; stirring for 10 min; and then adding and mixing wheat grass waste, and stirring for 6 h. The method according to claim 1, characterized in that the pulp waste liquor is pulp black liquor. The method according to claim 1, characterized in that in the mixture of the enzyme-pretreated wheat grass waste and the pulp waste liquor, the mass percentage of the enzyme-pretreated wheat grass waste is 72.0-74.0%, the mass percentage of the solid matter of the pulp waste liquor is 24.0-26.0%, and the mass percentage of water is 2.0-3.0%, with the sum of the three percentages being 100%. The method according to claim 1, characterized in that the specific conditions for heating and extrusion molding are a pressure of 6 to 8 MPa and a temperature of 100 to 120°C. The method according to claim 1, characterized in that the drying temperature is 60 to 65°C. Wheat grass waste granular fuel obtained by the method according to any one of claims 1 to 12. Use of the wheat grass waste granular fuel according to claim 13 in the clean energy field.