Method for resource utilization of yellow corn silage of straws

Abstract

The invention relates to the technical field of biomass resource utilization, in particular to a straw yellow silage resource utilization method. According to the method disclosed by the invention, the corn stalk yellow silage is used as a raw material, and xylose can be prepared through crushing, pretreatment, material system replacement and hydrolysis, so that resource utilization of the corn stalk yellow silage is realized; according to the method, the yellow corn silage is adopted as the raw material, the primary problem of'storage and transportation 'of straw as the raw material in the prior art is solved, meanwhile, pretreatment is simpler and more environmentally friendly, hydrolysis conditions are milder, the requirement for equipment is low, the method is environmentally friendly, production energy consumption can be effectively reduced, meanwhile, the xylose yield is high, and follow-up fermentation is not inhibited; the relation among five-material utilization of the straws is enhanced, and the comprehensive utilization capability is improved.

Description

Technical Field

[0001] The invention relates to the technical field of biomass resource utilization, and in particular to a method for resource utilization of straw yellow storage. Background Art

[0002] Non-grain biomass straw is a renewable resource with advantages such as wide distribution, large quantity and low price, and has demonstrated its importance in many fields. At present, straw is mainly used as fertilizer, feed, fuel, base material and raw material, referred to as "five materials". The comprehensive utilization of straw can not only effectively promote farmers' income and environmental protection, but also increase the added value of straw, which is of great significance to resource conservation and sustainable agricultural development.

[0003] At present, the utilization of straw as raw material only accounts for about 5% of the utilization of "five materials". The main reason for the low utilization of raw material is that the structure of straw is complex. The main components of cellulose, hemicellulose and lignin are tightly intertwined and difficult to open, making it difficult to fully utilize each component. Hemicellulose is easily soluble in acid solution. Industrial production often uses a large amount of high-concentration acid to treat straw, so as to extract hemicellulose and obtain xylose by hydrolysis, but there are problems such as high equipment requirements and environmental pollution. Although the preparation of xylose currently adopts pretreatment methods to open the intertwined structure in the straw, such as ultrasonic method and steam explosion method, and then dissolves it with acid to reduce the concentration and dosage of subsequent acid, there are still factors that are not conducive to industrial production, such as high equipment requirements and high cost of use.

[0004] Although straw has the advantage of comprehensive resource utilization, there are many problems to be solved in using straw as raw material, such as high collection, transportation and storage costs due to the difficulty of collection, transportation and storage, energy reduction due to corruption and mildew during storage, high mechanical energy consumption during crushing due to the thick and abundant wax layer on the surface of straw, and high pollution caused by the large amount of hydrolysis acid process. In addition, there is currently no clear and complete market procurement system for straw, which poses certain challenges to the capital operation of relevant operating companies. Therefore, finding a method that can solve the current problems of straw and then use it as raw material will be a major breakthrough in the development of the straw industry.

[0005] Straw yellow storage is currently mainly used as feed for livestock, and has formed commercial-scale production. Straw yellow storage itself has the advantages of fire safety and long-term preservation. The main components of straw yellow storage are similar to those of conventional straw, but the organizational structure is looser and easy to process as raw materials. At the same time, straw yellow storage has a complete capital operation loan system, which can alleviate the pressure of capital operation difficulties of biochemical enterprises. Therefore, in view of the shortcomings and deficiencies in the existing research technology of preparing xylose using non-grain biomass straw as raw material, the present invention proposes a method for resource utilization of straw yellow storage that can prepare xylose in a green and efficient manner, which is of great significance for realizing high-value utilization of all components of agricultural biomass. Summary of the invention

[0006] The purpose of the present invention is to provide a method for resource utilization of straw yellow storage, so as to solve the existing problems of "collection, storage and transportation", difficult pretreatment and high equipment production cost when preparing xylose using straw as raw material.

[0007] To achieve the above object, the present invention adopts the following technical scheme: a method for resource utilization of straw yellow storage, comprising the following steps:

[0008] S1. Crush the yellow straw and seal it for later use;

[0009] S2, adding the crushed straw yellow storage in S1 into the reactor, and pre-treating it, discharging the liquid after pre-treatment, and obtaining a solid component and a liquid component;

[0010] S3, adding a hydrolyzate to the solid component obtained in S2 to replace the material system, and discharging the liquid after the replacement is completed to obtain a solid component after the replacement is completed;

[0011] S4, adding the hydrolyzate to the solid component after the replacement in S3 and reacting, and discharging the liquid after the reaction, and the obtained liquid is xylose syrup;

[0012] S5. The liquid component obtained in S2 is recycled for pretreatment of the next batch of materials.

[0013] Furthermore, in the above S1, the straw yellowing includes but is not limited to corn straw yellowing and rice and wheat straw yellowing; the crushing equipment includes but is not limited to a vertical shaft crusher, a two-stage crusher and a hammer crusher; the length of the straw yellowing after crushing is 1 to 7 cm.

[0014] Furthermore, in the S2, the pretreatment uses a maleic acid-formic acid mixture, wherein the concentration of maleic acid is 0.45-2.25 g / L, and the concentration of formic acid is 0.5-3 g / L; the mixing ratio of maleic acid to formic acid is 1:1-5; and the solid-liquid ratio of straw yellow storage to the maleic acid-formic acid mixture is 1:1-5.

[0015] Furthermore, the pretreatment time is 20 to 90 minutes, the temperature is 100 to 150° C., and the pressure is 0.15 to 0.7 MPa; after the pretreatment, the liquid is cooled to below 100° C., and then the liquid is discharged.

[0016] Furthermore, in the S3-S4, the hydrolyzate is a 0.2-1.8% sulfuric acid solution.

[0017] Furthermore, in the S3, the solid-liquid ratio of the solid component to the hydrolyzate is 1:0.5-12; and the number of replacements is 1-4 times.

[0018] Furthermore, in the S4, the solid-liquid ratio of the solid component to the hydrolyzate is 1:1-12.

[0019] Furthermore, the reaction time is 50 to 130 minutes, the reaction temperature is 120 to 180° C., and the reaction pressure is 0.2 to 1.2 MPa.

[0020] Furthermore, in the xylose syrup, the yield of xylose relative to hemicellulose can reach more than 95%.

[0021] Furthermore, in the above-mentioned S5, the liquid component is recycled 3 to 8 times.

[0022] Beneficial effects of the present invention:

[0023] 1. The method of the present invention uses yellow straw storage instead of untreated straw for raw material utilization, which expands the utilization scope of yellow straw storage, increases the proportion of feed utilization and raw material utilization in the "five materials" utilization, establishes the connection between feed utilization and raw material utilization, and achieves a new breakthrough in the field of straw biochemical industry;

[0024] 2. The method of the present invention uses straw yellow storage as raw material, and the source of straw yellow storage resources is stable, which solves the primary problem of "collection, storage and transportation" for comprehensive utilization of straw raw materials. The straw yellow storage itself has a loose structure and is easy to handle, which greatly reduces the pretreatment level. The pretreatment is simple and environmentally friendly, the hydrolysis reaction conditions are mild, the operation is simple, the equipment requirements are low, the xylose yield is high, and the production energy consumption can be effectively reduced; and it has no inhibitory effect on subsequent fermentation, which strengthens the connection between the "five materials" of straw and improves the comprehensive utilization capacity;

[0025] 3. The pretreatment method of the present invention uses a maleic acid-formic acid system to open the straw lignocellulose structure. Maleic acid and formic acid can limit the generation of furfural and the dissolution of lignin. After low-concentration sulfuric acid hydrolysis treatment, high-purity xylose is obtained with a yield of up to 95.2%;

[0026] 4. The pretreatment and hydrolysis reaction of the method of the present invention are carried out in the same reactor, and no additional equipment is required for operation. It can be fully applied to environmentally friendly industrial production, and the production cost is greatly reduced. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention.

[0028] In the technical solution of the present invention, the solid-liquid ratio is the ratio of the solid mass to the liquid volume.

[0029] Example 1

[0030] The corn stalk yellow tucks were crushed and sealed for storage. After testing, the average length of the crushed corn stalk yellow tucks was 4.2 cm; the cellulose content in the corn stalk yellow tucks was 32.3%, the hemicellulose content was 25.8%, and the lignin content was 15.4%.

[0031] Take 100 kg of the above corn straw yellow silage powder and add it to a steam hydrolysis tank, and add a maleic acid-formic acid mixture to the steam hydrolysis tank at a solid-liquid ratio of 1:3 to pretreat the corn straw yellow silage; the pretreatment time is 60 minutes, the temperature is 120°C, and the pressure is 0.5 MPa.

[0032] Wherein, for the maleic acid-formic acid mixture, the concentration of maleic acid is 1 g / L, the concentration of formic acid is 2 g / L, and the mixing ratio of maleic acid to formic acid is 1:3.

[0033] After the temperature of the pretreated liquid is cooled to below 100°C, the liquid component in the steam hydrolysis tank is discharged, and the liquid component can be used for pretreatment of the next batch of materials; at this time, there are solid components remaining in the steam hydrolysis tank, and 1% sulfuric acid solution is added to the solid components to replace the material system; during the process, the solid-liquid ratio of the solid component to the sulfuric acid solution is 1:5, and the number of replacements is 3 times.

[0034] 1% sulfuric acid solution was added again to the solid component after the replacement, with a solid-liquid ratio of 1:6. After the addition was completed, the reaction was carried out at 0.3 MPa and 130°C for 2 hours. After the reaction was completed, the temperature dropped below 100°C, and the liquid material obtained by the reaction was discharged. The obtained liquid material was xylose syrup, and the volume of the xylose syrup was 591L.

[0035] The results showed that the concentration of xylose in the xylose syrup was 41.17 g / L, and the yield was 94.3% relative to hemicellulose.

[0036] Example 2

[0037] The wheat straw yellow silage was crushed and sealed for storage. After testing, the average length of the crushed wheat straw yellow silage was 3.1 cm; the cellulose content of the wheat straw yellow silage was 32.3%, the hemicellulose content was 29.8%, and the lignin content was 8.1%.

[0038] Take 100 kg of the above-mentioned wheat straw yellow silage powder and add it to a steam hydrolysis tank, and add maleic acid-formic acid mixed solution to the steam hydrolysis tank with a solid-liquid ratio of 1:5 to pretreat the corn straw yellow silage; the pretreatment time is 30 minutes, the temperature is 130°C, and the pressure is 0.3Mpa.

[0039] Wherein, for the maleic acid-formic acid mixture, the concentration of maleic acid is 1 g / L, the concentration of formic acid is 2 g / L, and the mixing ratio of maleic acid to formic acid is 1:3.

[0040] After the temperature of the pretreated liquid is cooled to below 100°C, the liquid component in the steam hydrolysis tank is discharged, and the liquid component can be used for pretreatment of the next batch of materials; at this time, there are solid components remaining in the steam hydrolysis tank, and 1% sulfuric acid solution is added to the solid components to replace the material system; during the process, the solid-liquid ratio of the solid component to the sulfuric acid solution is 1:5, and the number of replacements is 3 times.

[0041] 1% sulfuric acid solution was added again to the solid component after the replacement, with a solid-liquid ratio of 1:7. After the addition was completed, the reaction was carried out at 0.5 MPa and 140°C for 2 hours. After the reaction was completed, the temperature dropped below 100°C, and the liquid material obtained by the reaction was discharged. The obtained liquid material was xylose syrup, and the volume of the xylose syrup was 692L.

[0042] The results showed that the concentration of xylose in the xylose syrup was 41.0 g / L, and the yield was 95.2% relative to hemicellulose.

[0043] Comparative Example 1

[0044] The corn stalks were crushed and set aside. After testing, the average length of the corn stalks was 4.9 cm, the cellulose content in the corn stalks was 33.1%, the hemicellulose content was 26.5%, and the lignin content was 14.6%.

[0045] The other steps were the same as those in Example 1, and the volume of the final xylose syrup was 592 L.

[0046] The results showed that the concentration of xylose in the xylose syrup was 32.91 g / L, and the yield was 73.5% relative to hemicellulose.

[0047] It can be seen that the treatment effect of corn stalks by the method of the present invention is obviously inferior to that of the treatment of corn stalk yellowing.

[0048] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone can derive other various forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, all technical solutions that are the same or similar to those of the present application fall within the protection scope of the present invention.

Claims

1. A method for resource utilization of yellow straw storage, characterized in that: The following steps are involved: S1. Crush the yellow straw and seal it for later use; S2, adding the crushed straw yellow storage in S1 into the reactor, and pre-treating it, discharging the liquid after pre-treatment, and obtaining a solid component and a liquid component; S3, adding a hydrolyzate to the solid component obtained in S2 to replace the material system, and discharging the liquid after the replacement is completed to obtain a solid component after the replacement is completed; S4, adding the hydrolyzate to the solid component after the replacement in S3 and reacting, and discharging the liquid after the reaction, and the obtained liquid is xylose syrup; S5. The liquid component obtained in S2 is recycled for pretreatment of the next batch of materials.

2. The method for resource utilization of yellow straw storage according to claim 1, characterized in that: In S1, the straw yellow storage includes but is not limited to corn straw yellow storage and rice and wheat straw yellow storage; the crushing equipment includes but is not limited to a vertical shaft crusher, a two-stage crusher and a hammer crusher; the length of the straw yellow storage after crushing is 1 to 7 cm.

3. The method for resource utilization of yellow straw storage according to claim 1, characterized in that: In the S2, the pretreatment uses a maleic acid-formic acid mixture, wherein the concentration of maleic acid is 0.45-2.25 g / L, and the concentration of formic acid is 0.5-3 g / L; the mixing ratio of maleic acid to formic acid is 1:1-5; and the solid-liquid ratio of straw yellow storage to the maleic acid-formic acid mixture is 1:1-5.

4. The method for resource utilization of yellow straw storage according to claim 3, characterized in that: The pretreatment time is 20 to 90 minutes, the temperature is 100 to 150° C., and the pressure is 0.15 to 0.7 MPa. After the pretreatment, the liquid is cooled to below 100° C., and then the liquid is discharged.

5. The method for resource utilization of yellow straw storage according to claim 1, characterized in that: In the above-mentioned S3-S4, the hydrolyzate is a 0.2-1.8% sulfuric acid solution.

6. The method for resource utilization of yellow straw storage according to claim 5, characterized in that: In the S3, the solid-liquid ratio of the solid component to the hydrolyzate is 1:0.5-12; and the number of replacements is 1-4 times.

7. The method for resource utilization of yellow straw storage according to claim 5, characterized in that: In the S4, the solid-liquid ratio of the solid component to the hydrolyzate is 1:1-12.

8. The method for resource utilization of yellow straw storage according to claim 7, characterized in that: The reaction time is 50-130 minutes, the reaction temperature is 120-180° C., and the reaction pressure is 0.2-1.2 MPa.

9. The method for resource utilization of yellow straw storage according to claim 8, characterized in that: In the xylose syrup, the yield of xylose relative to hemicellulose can reach more than 95%.

10. The method for resource utilization of yellow straw storage according to claim 1, characterized in that: In the above-mentioned S5, the liquid component is recycled 3 to 8 times.