Methods for producing amino acid-rich organic fertilizer by treating diseased and dead livestock and poultry using alkaline hydrolysis

Abstract

This application relates to the field of organic solid waste treatment, specifically disclosing a method for producing amino acid-rich organic fertilizer from diseased and dead livestock and poultry using alkaline hydrolysis. The technical solution is as follows: a. Crush the carcasses of diseased and dead livestock and poultry; b. Add calcium hydroxide as an alkali source and water to the crushed carcasses, controlling the amount of calcium hydroxide added to be 0.1–0.3 g / g dry matter; c. Perform hydrolysis at a temperature of 180℃–220℃ for 30–90 min; d. Obtain the hydrolysate and oil; e. Dilute the hydrolysate to obtain amino acid-rich organic fertilizer. This organic fertilizer can be directly applied to alkaline-loving plants, or applied to acid-loving plants by adding HCl. Under high-temperature conditions, the humic peak under alkaline-thermal hydrolysis is weakened compared to hydrothermal hydrolysis. Alkaline-thermal conditions can inhibit the production of toxic substances in the fertilizer product, while simultaneously reducing the nitrogen content and significantly increasing the calorific value of the bio-oil.

Description

Technical Field

[0001] This application relates to the field of organic solid waste treatment, and more specifically, it relates to a method for producing amino acid-rich organic fertilizer by treating diseased and dead livestock and poultry using alkaline hydrolysis. Background Technology

[0002] As the world's largest developing country, China has an extremely large livestock industry, which also produces a large number of diseased and dead livestock and poultry. If the carcasses of diseased and dead livestock and poultry are not properly disposed of, it will not only severely damage the livestock and poultry breeding industry, but also expose humans to the risk of zoonotic diseases and endanger the safety of livestock production and the ecological environment.

[0003] Currently, there are various methods for disposing of diseased and dead livestock and poultry, each with its own advantages and disadvantages. While landfill and incineration are inexpensive, they lack resource recycling capabilities, failing to address the issue of low economic efficiency. Furthermore, landfilling requires a certain amount of land and may even cause environmental pollution. Anaerobic fermentation and aerobic composting, although possessing some resource recycling capabilities, are very slow, typically requiring 3-6 months, and require a large land area, with unavoidable odors.

[0004] Although hot hydrolysis is more expensive, its effectiveness in treating pathogens in dead livestock and poultry far surpasses the four methods mentioned above. Furthermore, the product produced during the process is more economically viable than that from anaerobic fermentation and aerobic composting, offering better resource recycling and pollution control. Therefore, hot hydrolysis is gaining increasing attention. In the process of preparing amino acid liquid fertilizer from dead livestock and poultry, effectively increasing the amino acid conversion concentration and completely eliminating the biosafety risks posed by pathogens are the core challenges for process optimization. Associate Professor Yan Yixin of Zhengzhou University has shown that alkaline hydrolysis of sludge can not only effectively inhibit amino acid decomposition but also promote the full hydrolysis of proteins, increasing amino acid yield and producing high-quality liquid fertilizer with superior fertilizer efficiency and environmental friendliness. Research by Tang Yanfei of Tongji University indicates that among various alkaline reagents, calcium hydroxide is an ideal choice for alkaline hot hydrolysis due to its low cost and the synergistic effect of calcium ions on amino acid stability.

[0005] Therefore, this invention attempts to use the alkaline heat method for the treatment of diseased and dead livestock and poultry. Summary of the Invention

[0006] In order to address the problems of low amino acid conversion rate, high biosafety risk, and low resource utilization value in existing technologies, this application provides a method for producing amino acid-rich organic fertilizer by treating diseased and dead livestock and poultry using alkaline hydrolysis.

[0007] The method for producing amino acid-rich organic fertilizer by treating diseased and dead livestock and poultry using alkaline hydrolysis provided in this application adopts the following technical solution: A method for producing amino acid-rich organic fertilizer by treating diseased and dead livestock and poultry using alkaline hydrolysis includes the following steps: a. To break up the carcasses of diseased or dead livestock and poultry; b. Add the crushed carcasses of diseased and dead livestock and poultry to the reaction vessel, and add calcium hydroxide as an alkali source, controlling the amount of calcium hydroxide added to be 0.1-0.3 g / g dry matter. At the same time, add water and control the water content of the reaction system to be 85%-90%. c. Hydrolysis is carried out by reacting at a temperature of 180℃~220℃ for 30~90 minutes; d. Separate the reaction products into solid, liquid, and oil components to obtain hydrolysate and oil. e. Dilute the hydrolysate 80 to 100 times to obtain an organic fertilizer rich in amino acids. The pH of this organic fertilizer is around 8.5, which can be applied directly to alkaline-loving plants. Alternatively, the pH can be adjusted to around 6.5 by adding HCl and then applied to acid-loving plants.

[0008] By adopting the above technical solution, and by using calcium hydroxide as the alkali source and precisely controlling its addition amount within the range of 0.1–0.3 g / g dry matter, while controlling the water content of the reaction system at 85%–90% to construct the optimal reaction medium, and by strictly controlling the hydrolysis reaction temperature at 180℃–220℃ and ensuring a sufficient reaction time of 30–90 minutes to provide sufficient reaction energy, and by achieving the effective synergy between the above-mentioned alkaline environment and high temperature and high pressure conditions, this invention not only achieves the efficient hydrolysis of proteins from diseased and dead livestock and poultry into high-quality amino acid liquid fertilizer and completely inactivates pathogens, but also simultaneously produces high-quality bio-oils with lower nitrogen content and higher calorific value, thus achieving the dual goals of harmless treatment and high-value resource utilization of diseased and dead livestock and poultry.

[0009] Preferably, in step a, the carcasses of diseased and dead livestock and poultry are crushed into particles of 3-5 cm.

[0010] Preferably, in step b, the amount of calcium hydroxide added is 0.2 g / g dry matter.

[0011] Preferably, in step c, the reaction temperature is 200°C.

[0012] Preferably, in step c, the reaction time is 60 minutes.

[0013] Preferably, the solid-liquid-oil separation in step d is performed by centrifugal separation.

[0014] Preferably, after step e, step f may be included, in which acid is added to the diluted organic fertilizer to adjust the pH to 6.0-7.5.

[0015] Preferably, the acid added in step f is hydrochloric acid, and the concentration of the hydrochloric acid is 0.1 mol / L.

[0016] An amino acid-rich organic fertilizer is prepared by using an alkaline hydrolysis method to treat diseased and dead livestock and poultry to produce amino acid-rich organic fertilizer.

[0017] A high-quality bio-oil, prepared by any of the aforementioned methods.

[0018] In summary, this application has the following beneficial effects: (1) Breakthrough increase in amino acid nitrogen concentration: Under the reaction conditions of adding 0.1~0.3g / g dry matter calcium hydroxide, maintaining 85~90% water content, 180~220℃, and 30~90min, the amino acid nitrogen concentration in the hydrolysate was increased by about 4.7 times compared with the control group without alkali.

[0019] (2) Good sterilization effect: The high temperature of 180~220℃ combined with the alkaline environment of calcium hydroxide has an inactivation rate of >99.99% for stubborn pathogens such as African swine fever virus (ASFV) and Bacillus, far exceeding the requirements of the national standard (GB / T36850-2018).

[0020] (3) It has the advantage of universality: after the reaction is completed, it only needs to be diluted 80 to 100 times to be applied to alkaline crops. After dilution, the pH can be adjusted by adding HCl until it is suitable for neutral crops and acid-loving crops. It can also avoid soil compaction caused by pH>10 of traditional alkaline hydrolysis products.

[0021] (4) It is economical: the unit price of calcium hydroxide is 1 / 3 of that of sodium hydroxide, and no equipment resistant to strong alkali corrosion is required, resulting in lower equipment investment.

[0022] (5) Reduce the generation of toxic substances in fertilizers: Under high temperature conditions, the peak of humic substances under alkaline hydrolysis is weakened compared with that under hydrothermal hydrolysis. Under alkaline hydrolysis conditions, the humification process of nitrogen-containing substances such as amino acids and carbohydrates can be inhibited, and the generation of humic substances such as polycyclic aromatic hydrocarbons that inhibit plant growth and development can be avoided. Alkaline hydrolysis can avoid the generation of toxic substances in fertilizer products.

[0023] (6) Improve the quality of liquid and oil phase products: Alkaline hydrolysis at this temperature inhibits the Maillard reaction, reduces toxic substances such as furfural and 5-HMF in the liquid phase product that inhibit seed germination, and generally reduces the proportion of nitrogen-containing heterocyclic compounds such as pyrazine and pyridine in the hydrolysate, as well as significantly reduces organic acids, esters, and carbohydrates. This unique compositional characteristic gives alkaline hydrolysate a significant advantage as an amino acid fertilizer. At the same time, the nitrogen content of bio-oil is reduced and the calorific value is significantly increased, making it more suitable for fertilizer application and high-quality bio-oil acquisition. This allows it to be used as a high-quality biofuel or industrial raw material, and has a higher economic value than oil produced by the traditional hydrothermal method, thus maximizing the value of diseased and dead livestock and poultry resources. Attached Figure Description

[0024] Figure 1 This is a flowchart of the method for producing amino acid-rich organic fertilizer by treating diseased and dead livestock and poultry using alkaline hydrolysis, as provided in this application. Detailed Implementation

[0025] A method for producing liquid organic fertilizer rich in amino acids from diseased and dead livestock and poultry using alkaline hydrolysis includes the following steps: (1) Pre-treatment stage: After surface disinfection, the collected dead animal carcasses are transported in a sealed manner to the crushing section, where a shear crusher is used to crush the carcasses into uniform particles of 3-5cm to form reaction raw materials. (2) Alkali source control: Calcium hydroxide is selected as the alkali source, and the amount of alkali added is 0.1~0.3g / g dry matter; (3) Reaction stage: Add the crushed raw materials into the reactor, control the water content to be 85-90%, the reaction temperature to be 180-220℃, react for 30-90 minutes, and add calcium hydroxide in proportion; (4) Solid-liquid-oil separation: The solid, liquid, and oil phases are separated by centrifugation; (5) Product fertilizer efficiency: In the amino acid liquid fertilizer produced by the above alkaline hydrolysis method, the concentration of amino acid nitrogen in the product is increased by about 4.7 times compared with the reaction result without calcium hydroxide under the same conditions. This significantly improves the fertilizer efficiency of the amino acid liquid fertilizer. (6) Application of amino acid liquid fertilizer: Dilute the hydrolysate at a mass ratio of 1:80~100. After dilution, the pH should be 8.0~9.0, which meets the pH range requirements of "NY1429-2010 Amino Acid Water-Soluble Fertilizer" (3.0~9.0). If the crop is an acid-loving plant, add 0.1mol / L HCl solution to the diluted solution until the pH stabilizes at 6.0~7.5. At this time, the pH value is within the optimal growth range for acid-loving plants and avoids amino acid denaturation.

[0026] The specific embodiments of the present invention are described below with reference to examples to provide a better understanding of the invention. These examples are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions in the art or as recommended by the manufacturer; the raw materials and reagents used, unless otherwise specified, are all commercially available from the conventional market. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention are within the scope of protection claimed by the present invention.

[0027] Example 1 Please see the appendix Figure 1 The collected carcasses of diseased and dead cattle were disinfected. After reaching a certain quantity (500 kg), they were crushed to obtain granules of 3-5 cm square. These granules were then added to a reaction vessel, and 900 kg of water was added according to the 72% moisture content of the diseased and dead cattle, maintaining the moisture content of all substances in the reaction vessel at 90%. Subsequently, based on the 28% solids content of the diseased and dead cattle, 28 kg of calcium hydroxide (0.2 g / g dry matter) was added, and the reaction was carried out at 200℃ for 60 min with stirring at 300 rpm. Finally, 1325.8 kg of hydrolysate with a concentration of 3026.91 mg / L was obtained. After diluting it with water at a ratio of 1:80, an amino acid liquid fertilizer with a pH of 8.45 was obtained.

[0028] Example 2 The collected carcasses of diseased and dead cattle were disinfected. After reaching a certain quantity (500 kg), they were crushed to obtain particles of 3-5 cm square. These particles were then added to a reaction vessel, and 433 kg of water was added based on the 72% moisture content of the diseased and dead cattle, maintaining the total moisture content of the substances in the reaction vessel at 85%. Subsequently, based on the 28% solids content of the diseased and dead cattle, 28 kg of calcium hydroxide (0.2 g / g dry matter) was added. The reaction was carried out at 220℃ for 60 min, with stirring maintained at 300 rpm. The final product yielded 854.6 kg of hydrolysate with a concentration of 2154.23 mg / L, significantly higher than the amino acid concentration in hydrolysate under the same conditions without the addition of calcium hydroxide. Simultaneously, it effectively inhibited the formation of toxic substances such as melanoidins and 5-HMF.

[0029] Example 3 The collected carcasses of diseased and dead cattle were disinfected. After reaching a certain quantity (500 kg), they were crushed to obtain particles of 3-5 cm square. These particles were then added to a reaction vessel, and 900 kg of water was added based on the 72% moisture content of the diseased and dead cattle, maintaining the moisture content of all substances in the reaction vessel at 90%. Subsequently, based on the 28% solids content of the diseased and dead cattle, 28 kg of calcium hydroxide (0.2 g / g dry matter) was added. The reaction was carried out at 180℃ for 60 min, with stirring maintained at 300 rpm. Finally, 1323 kg of hydrolysate with a concentration of 2178.86 mg / L was obtained, which is far higher than the amino acid concentration in the hydrolysate under the same conditions without the addition of calcium hydroxide.

[0030] Example 4 The procedure of Example 1 was repeated, except that 14 kg of calcium hydroxide was added, which is 0.1 g / g dry matter. After the reaction was completed, the concentration of amino acid nitrogen in the hydrolysate was measured to be 2488.5 mg / L. The results show that, at this addition amount, the concentration of amino acid nitrogen in the hydrolysate is still significantly higher than that of Comparative Example 1 without the addition of an alkaline source.

[0031] Example 5 The procedure of Example 1 was repeated, except that 42 kg of calcium hydroxide was added, which is 0.3 g / g dry matter. After the reaction was completed, the concentration of amino acid nitrogen in the hydrolysate was measured to be 3112.3 mg / L. The results show that a high concentration of amino acid hydrolysate can also be obtained at this dosage.

[0032] Example 6 The procedure of Example 1 was repeated, except that the reaction time was 30 min. After the reaction, the concentration of amino acid nitrogen in the hydrolysate was measured to be 2085.7 mg / L. The results show that at this reaction time, effective hydrolysis of diseased and dead livestock and poultry can be achieved, and a high concentration of amino acids can be obtained.

[0033] Example 7 The procedure of Example 1 was repeated, except that the reaction time was extended to 90 min. After the reaction, the concentration of amino acid nitrogen in the hydrolysate was measured to be 3095.1 mg / L. The results indicate that a high-quality amino acid hydrolysate can still be obtained by extending the reaction time.

[0034] Example 8 The hydrolysate prepared in Example 1 was diluted with water at a ratio of 1:100. The pH value of the diluted liquid fertilizer was measured to be 8.25, which is within a suitable alkaline range.

[0035] Subsequently, take 1L of the diluted liquid fertilizer and, while stirring, add dropwise a 0.1mol / L hydrochloric acid solution, monitoring the pH in real time until it stabilizes at 6.5. Record the consumption of approximately 150mL of hydrochloric acid solution. The resulting liquid fertilizer has a suitable pH value, making it suitable for acid-loving crops.

[0036] Comparative Example 1 The collected carcasses of diseased and dead cattle were disinfected. After reaching a certain quantity (500 kg), they were crushed to obtain particles of 3-5 cm square. These particles were then added to a reaction vessel, and 900 kg of water was added according to the 72% moisture content of the diseased and dead cattle, maintaining the moisture content of all substances in the reaction vessel at 90%. The reaction was carried out at 200℃ for 60 minutes with stirring at 300 rpm. The final product yielded 1325.8 kg of hydrolysate with a concentration of 642.27 mg / L, significantly lower than the amino acid content in hydrolysate under alkaline hydrolysis conditions. However, this hydrolysate contained a high content of heterocyclic nitrogen compounds, which may require additional post-treatment to meet safety standards for agricultural applications.

[0037] Comparative Example 2 The collected carcasses of diseased and dead cattle were disinfected. After reaching a certain quantity (500 kg), they were crushed to obtain particles of 3-5 cm square. These particles were then added to a reaction vessel, and 433 kg of water was added according to the 72% moisture content of the diseased and dead cattle, maintaining the moisture content of all substances in the reaction vessel at 85%. The reaction was carried out at 220℃ for 60 minutes with stirring at 300 rpm. The final product yielded 854.6 kg of hydrolysate with a concentration of 950.53 mg / L, significantly lower than the amino acid content in hydrolysate under alkaline hydrolysis conditions.

[0038] As can be seen from the comparison between Examples 1-8 and Comparative Examples 1-2, the present invention, by adding a specific proportion of calcium hydroxide under specific moisture content, temperature and time conditions, can increase the concentration of amino acid nitrogen in the hydrolysate by several times, thereby improving the quality and value of the fertilizer, demonstrating the significant advantages of the method of the present invention.

Claims

1. A method for producing amino acid-rich organic fertilizer by treating diseased and dead livestock and poultry using alkaline hydrolysis, characterized in that: Includes the following steps: a. To break up the carcasses of diseased or dead livestock and poultry; b. Add the crushed carcasses of diseased and dead livestock and poultry to the reaction vessel, and add calcium hydroxide as an alkali source, controlling the amount of calcium hydroxide added to be 0.1-0.3 g / g dry matter. At the same time, add water and control the water content of the reaction system to be 85%-90%. c. Hydrolysis is carried out by reacting at a temperature of 180℃~220℃ for 30~90 minutes; d. Separate the reaction products into solid, liquid, and oil components to obtain hydrolysate and oil. e. Dilute the hydrolysate 80 to 100 times to obtain an organic fertilizer rich in amino acids. The pH of this organic fertilizer is around 8.5, which can be applied directly to alkaline-loving plants. Alternatively, the pH can be adjusted to around 6.5 by adding HCl and then applied to acid-loving plants.

2. The method for producing amino acid-rich organic fertilizer by treating diseased and dead livestock and poultry using alkaline hydrolysis according to claim 1, characterized in that: In step a, the carcasses of diseased and dead livestock and poultry are crushed into particles of 3-5 cm.

3. The method for producing amino acid-rich organic fertilizer by treating diseased and dead livestock and poultry using alkaline hydrolysis according to claim 1, characterized in that: In step b, the amount of calcium hydroxide added is 0.2 g / g dry matter.

4. The method for producing amino acid-rich organic fertilizer by treating diseased and dead livestock and poultry using alkaline hydrolysis according to claim 1, characterized in that: In step c, the reaction temperature is 200°C.

5. The method for producing amino acid-rich organic fertilizer by treating diseased and dead livestock and poultry using alkaline hydrolysis according to claim 1, characterized in that: In step c, the reaction time is 60 minutes.

6. The method for producing amino acid-rich organic fertilizer by treating diseased and dead livestock and poultry using alkaline hydrolysis according to claim 1, characterized in that: The solid-liquid-oil separation in step d is performed by centrifugal separation.

7. The method for producing amino acid-rich organic fertilizer by treating diseased and dead livestock and poultry using alkaline hydrolysis according to claim 1, characterized in that: After step e, step f may be included, in which acid is added to the diluted organic fertilizer to adjust the pH to 6.0-7.

5.

8. The method for producing amino acid-rich organic fertilizer by treating diseased and dead livestock and poultry using alkaline hydrolysis according to claim 7, characterized in that: The acid added in step f is hydrochloric acid, and the concentration of the hydrochloric acid is 0.1 mol / L.

9. An organic fertilizer rich in amino acids, characterized in that: It is prepared by the method of producing amino acid-rich organic fertilizer by treating diseased and dead livestock and poultry using alkaline hydrolysis as described in claims 1 to 8.

10. A high-quality bio-oil, characterized in that: Prepared by the method described in any one of claims 1 to 8.

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