A method for converting Chinese medicine residue into Chinese herbal medicine organic fertilizer using cobalt-iron catalyst

Abstract

The present invention belongs to the field of agricultural technology, and in particular to a method for converting Chinese medicine residues into Chinese herbal medicine organic fertilizer using a cobalt-iron catalyst. The method comprises the following steps: (1) synthesizing a cobalt-iron catalyst; (2) mixing and pyrolyzing the Chinese medicine residues and the cobalt-iron catalyst; (3) activating the pyrolysis product to obtain the Chinese herbal medicine organic fertilizer. The process of the present invention is simple and easy to operate, and the prepared cobalt-iron catalyst has excellent catalytic performance and good cyclic stability, and can efficiently and quickly convert the Chinese medicine residues into Chinese herbal medicine organic fertilizer. At the same time, the prepared Chinese herbal medicine organic fertilizer has good water solubility, is rich in abundant plant growth nutrients, and has the effect of increasing production and increasing efficiency of Chinese herbal medicine.

Description

Technical Field

[0001] The invention belongs to the technical field of agriculture, and in particular relates to a method for converting Chinese medicine residues into Chinese herbal medicine organic fertilizer by utilizing a cobalt-iron catalyst. Background Art

[0002] Applying organic fertilizer is an important method to achieve high and stable yield of Chinese herbal medicine. Organic fertilizer, commonly known as farmyard manure, refers to slow-release fertilizer containing a large amount of biological matter, animal and plant residues, excrement, biological waste and other substances. On the one hand, it can provide the nutrients needed by plants and enhance the plant's disease resistance, drought resistance and waterlogging resistance; on the other hand, it can increase and supplement soil organic matter, and the organic matter in the soil can significantly improve the physical and chemical properties of the soil, improve the soil's tillage properties, enhance water infiltration capacity, improve the soil's water storage, fertilizer retention, fertilizer supply and drought and waterlogging resistance, increase production and improve crop quality significantly, improve food safety and greenness, and is also one of the basic conditions for the current agricultural products to achieve high quality and high prices. In addition, after organic fertilizer is applied to the land, the beneficial biological activities improve the soil structure and increase the soil's ability to retain water and fertilizer, thereby reducing the loss of nutrients, which can significantly increase the effective utilization rate of chemical fertilizers and reduce the amount of chemical fertilizers used, thereby reducing the cost of fertilization.

[0003] In recent years, Chinese medicine residues have been widely reported as a good raw material for organic fertilizer. Chinese medicine residues contain steroids, terpenes, a-type tea acetic acid, cinnamic acid, coumaric acid, phenylacetic acid, ferulic acid and other plant endogenous growth hormones, which can promote plant growth through direct or indirect effects. At the same time, Chinese medicine residues also have the characteristics of loose texture and good air permeability, which can be used to improve the permeability of soil and are a natural raw material for organic fertilizer. At present, the preparation of organic fertilizer is mainly based on fermentation, which has simple process conditions and is easy to operate. Patent CN109320336A discloses a method for preparing organic tea fertilizer by fermenting solid waste such as Chinese medicine residues. The organic tea fertilizer described in the patent has the characteristics of stable fertilizer effect, rich in humus, various nutrient elements and pollution-free, and can improve the quality of tea. Patent CN111377771A discloses a flower fertilizer for preparing Areca palm using Chinese medicine residues and a manufacturing method thereof. The fertilizer described in the patent can promote the absorption of nutrients by Areca palm and significantly increase the content of chlorophyll in leaves. However, the fermentation method has some disadvantages that are difficult to overcome, such as long fermentation cycle, easy breeding of bacteria and easy odor.

[0004] In view of the current practical problem of using Chinese medicine residue to prepare organic fertilizer, this patent invented a method of using cobalt-iron catalyst to transform Chinese medicine residue into water-soluble organic fertilizer for Chinese herbal medicine. The present invention uses Chinese medicine residue as raw material, uses homemade cobalt-iron catalyst, and through drying, grinding, catalytic pyrolysis and activation processes, quickly obtains Chinese herbal medicine organic fertilizer, which has great economic and environmental benefits.

[0005] In order to achieve the above object, the present invention provides the following technical solutions.

[0006] (1) Synthesis of cobalt-iron catalyst: adding an aqueous solution of oxalate to a mixed solution containing cobalt salt and iron salt to react, collecting the precipitated product after the reaction is completed, washing, drying, and calcining to obtain a cobalt-iron catalyst.

[0007] (2) Mixing the Chinese medicinal residue powder with the cobalt-iron catalyst obtained in step (1), introducing protective gas for pyrolysis.

[0008] (3) adding the pyrolysis product to an alkaline solution for reaction; after the reaction is completed, filtering out the solid residue, and drying the remaining liquid to obtain a Chinese herbal medicine organic fertilizer.

[0009] Preferably, the oxalate in step (1) is one or more of sodium oxalate, potassium oxalate, calcium oxalate, lithium oxalate, potassium iron oxalate, magnesium oxalate, and ammonium oxalate.

[0010] Preferably, the cobalt salt in step (1) is one or more of cobalt sulfate, cobalt nitrate and cobalt chloride.

[0011] Preferably, the iron salt in step (1) is one or more of ferric sulfate, ferrous sulfate, ferric nitrate, ferrous nitrate and ferric chloride.

[0012] Preferably, the solvents of the mixed solution in step (1) are ethylene glycol and water.

[0013] Preferably, the alkali solution in step (3) is one or more of calcium hydroxide aqueous solution, ammonia aqueous solution, potassium hydroxide aqueous solution, and sodium hydroxide aqueous solution.

[0014] Preferably, the concentration of the oxalate in step (1) is 0.1-1 mol / L; the molar ratio of the cobalt salt to the iron salt is 1:0.5-1:3; the volume ratio of ethylene glycol to water is 1:1-1:10; and the concentration of the cobalt salt and the iron salt is 0.5-4 mol / L.

[0015] Preferably, the reaction temperature in step (1) is 20-70°C; the drying temperature is 80±20°C, and the drying time is 12±4h; the roasting temperature is 400-700°C, and the roasting time is 3±1h.

[0016] Preferably, the mesh size of the Chinese medicinal residue powder in step (2) is 200-400 meshes; and the mass ratio of the cobalt-iron catalyst to the Chinese medicinal residue powder is 1:10-1:100.

[0017] Preferably, the Chinese medicine residue in step (2) is the residue extracted from Chinese medicinal materials; the Chinese medicinal materials are one or more of licorice, red ginseng, Corydalis yanhusuo, chrysanthemum, white peony root, atractylodes macrocephala, tangerine peel, pinellia, costusroot, poria, salvia miltiorrhiza, astragalus, ginseng, angelica, codonopsis pilosula, etc.

[0018] Preferably, the pyrolysis temperature in step (2) is 200-550° C., and the pyrolysis time is 60-300 min;

[0019] The protective gas in step (2) is one or more of nitrogen, hydrogen, carbon dioxide or argon.

[0020] Preferably, the pyrolysis method in step (2) is one-step pyrolysis or staged pyrolysis.

[0021] Preferably, the concentration of the alkaline solution in step (3) is 1 to 5 mol / L; the ratio of the pyrolysis product to the alkaline solution is 1 g:2 mL to 1 g:10 mL; and the reaction conditions in step (3) are ultrasonication at room temperature for 30 to 120 min.

[0022] The patent principle of the present invention is: the present invention utilizes cobalt-iron catalyst to thermally crack amino acids, saponins, cellulose, hemicellulose, lignin and other macromolecular substances in traditional Chinese medicine residues into small molecular oligomers, and then uses alkaline solution to activate and extract small molecular oligomers, steroids, terpenes, a-type theacetic acid, cinnamic acid, coumaric acid, phenylacetic acid, ferulic acid and other small molecular plant endogenous growth hormones and their derivatives contained in the traditional Chinese medicine residues themselves, and finally obtains water-soluble traditional Chinese herbal medicine organic fertilizer.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) The operation process of the present invention is simple, rapid, easy to industrialize and scale up, and no odor is generated during the preparation process.

[0025] (2) The organic fertilizer prepared by the present invention has good water solubility, which is more conducive to the absorption of plants such as Chinese herbal medicines.

[0026] (3) The cobalt-iron catalyst prepared by the present invention is a micron-sized material with a porous structure, which not only has an extremely high catalytic conversion efficiency, but also has magnetic recyclability and excellent cycle stability.

[0027] (4) The Chinese herbal medicine organic fertilizer prepared by the present invention is rich in plant growth nutrient elements and has the effect of increasing the yield and efficiency of Chinese herbal medicine. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a process flow chart of the present invention;

[0029] Figure 2 is a scanning electron microscope image of the cobalt-iron catalyst of Example 1;

[0030] Figure 3 is the X-ray diffraction pattern of the cobalt-iron catalyst of Example 1;

[0031] Figure 4 This is a photo of the water-soluble organic fertilizer obtained in Example 1;

[0032] Figure 5 This is a scanning electron microscope image of the water-soluble organic fertilizer obtained in Example 1;

[0033] Figure 6 This is a photo of the water-soluble organic fertilizer obtained in Example 1 dispersed in water;

[0034] Figure 7 The performance cycle stability diagram of the cobalt-iron catalyst of Example 2; DETAILED DESCRIPTION

[0035] The present invention will be further described below in conjunction with specific embodiments. These embodiments should be understood to be only used to illustrate the present invention and not to limit the scope of protection of the present invention. After reading the contents of the present invention, various changes or modifications made to the present invention based on the principles of the present invention also fall within the scope defined by the claims of the present invention.

[0036] Example 1

[0037] A method for converting Chinese medicine residue into Chinese herbal medicine organic fertilizer using cobalt-iron catalyst, the process flow chart of which is as follows Figure 1 The specific preparation steps are as follows:

[0038] (1) Synthesis of cobalt-iron catalyst: First, 0.04 mmol lithium oxalate was ultrasonically dissolved in 90 mL water to form solution A; 10 mmol CoSO4·7H2O and 20 mmol FeSO4·6H2O were dissolved in a mixed solution of ethylene glycol (10 mL) and water (20 mL) to form solution B, which was heated in a 35°C water bath; then solution A was rapidly poured into solution B and magnetically stirred for 30 min; after the reaction was completed, the precipitated product was collected, washed, and dried at 80°C for 12 h; finally, the dried product was placed in a muffle furnace and calcined at 450°C for 3 h to obtain a magnetic black cobalt-iron catalyst.

[0039] (2) Drying, crushing and sieving the ginseng residue to obtain 200-mesh residue powder; taking 0.1 g of the cobalt-iron catalyst prepared in step (1) and 10 g of the residue powder obtained in step (2) and mixing them evenly; then placing the mixture in a tubular furnace, heating at a rate of 5° C. / min, pyrolyzing at 350° C. in a nitrogen atmosphere, keeping the temperature for 2 h, and cooling naturally.

[0040] (3) After the reaction is completed and the furnace temperature drops to room temperature, the pyrolysis product is added to 50 mL of potassium hydroxide solution (3 mol / L) and ultrasonicated at room temperature for 60 min; after the reaction, the insoluble solid is filtered out, and the remaining liquid is dried to obtain a water-soluble organic fertilizer, and the catalyst is recovered from the insoluble solid by magnetic separation.

[0041] Organic fertilizer yield = organic fertilizer mass / drug residue powder mass

[0042] The scanning electron microscope image of the cobalt-iron catalyst prepared in Example 1 is as follows: Figure 2 As shown, Figure 3 The X-ray diffraction pattern of the cobalt-iron catalyst shows that the cobalt-iron catalyst in Example 1 is CoFe2O4; the organic fertilizer yield is calculated to be 92.4%; Figure 4 This is a photo of the water-soluble organic fertilizer of Example 1; Figure 5 This is a scanning electron microscope image of the water-soluble organic fertilizer of Example 1; Figure 6 This is a digital photo of the water-soluble organic fertilizer dispersed in water in Example 1.

[0043] Example 2

[0044] A method for converting Chinese medicine residue into Chinese herbal medicine organic fertilizer using cobalt-iron catalyst, the process flow chart of which is as follows Figure 1 The specific preparation steps are as follows:

[0045] (1) Synthesis of cobalt-iron catalyst: 0.03 mmol lithium oxalate was ultrasonically dissolved in 90 mL water to form solution A; 10 mmol CoSO4·7H2O and 10 mmol FeSO4·6H2O were dissolved in a mixed solution of ethylene glycol (15 mL) and water (15 mL) to form solution B, which was heated in a 35°C water bath; solution A was quickly poured into solution B, followed by magnetic stirring for 30 min; after the reaction was completed, the precipitated product was collected, washed, and dried at 80°C for 12 h; the dried product was placed in a muffle furnace and calcined at 450°C for 3 h to obtain a magnetic black cobalt-iron catalyst.

[0046] (2) drying, crushing and sieving the ginseng residue to obtain 200-mesh residue powder; taking 0.1 g of the cobalt-iron catalyst prepared in step (1) and 10 g of the residue powder obtained in step (2) and mixing them evenly; placing the mixture in a tubular furnace, heating the mixture at a rate of 5° C. / min, first heating the mixture to 200° C. and keeping the temperature for 1 h, then heating the mixture to 450° C. and keeping the temperature for 1 h, the whole process being carried out under a nitrogen atmosphere, and cooling the mixture naturally;

[0047] (3) After the reaction is completed and the furnace temperature drops to room temperature, the pyrolysis product is added to 40 mL of potassium hydroxide solution (3 mol / L), and ultrasonicated at room temperature for 60 min; after the reaction, the insoluble solid is filtered out, and the remaining liquid is dried to obtain a water-soluble organic fertilizer, and the catalyst is recovered from the insoluble solid by magnetic separation;

[0048] Organic fertilizer yield = organic fertilizer mass / drug residue powder mass.

[0049] After calculation, the yield of organic fertilizer obtained in Example 2 is 98.5%; Figure 7The performance cycle stability diagram of the cobalt-iron catalyst in Example 2 is shown in FIG. 1 . The cycle test shows that the cobalt-iron catalyst in Example 2 has excellent stability.

[0050] Example 3

[0051] A method for converting Chinese medicine residue into Chinese herbal medicine organic fertilizer using cobalt-iron catalyst, the process flow chart of which is as follows Figure 1 The specific preparation steps are as follows:

[0052] (1) Synthesis of cobalt-iron catalyst: 0.03 mmol lithium oxalate was ultrasonically dissolved in 90 mL water to form solution A; 10 mmol CoSO4·7H2O and 10 mmol FeSO4·6H2O were dissolved in a mixed solution of ethylene glycol (10 mL) and water (30 mL) to form solution B, which was heated in a 35°C water bath; solution A was quickly poured into solution B, and then magnetically stirred for 30 min; after the reaction was completed, the precipitated product was collected, washed, and dried at 80°C for 12 h; the dried product was placed in a muffle furnace and calcined at 450°C for 3 h to obtain a magnetic black cobalt-iron catalyst.

[0053] (2) drying, crushing and sieving the ginseng residue to obtain 200-mesh residue powder; taking 0.1 g of the cobalt-iron catalyst prepared in step (1) and 10 g of the residue powder obtained in step (2) and mixing them evenly; placing the mixture in a tubular furnace, heating the mixture at a rate of 5° C. / min, first heating the mixture to 200° C. and keeping the temperature for 1 h, then heating the mixture to 450° C. and keeping the temperature for 1 h, the whole process being carried out under a nitrogen atmosphere, and cooling the mixture naturally;

[0054] (3) After the reaction is completed and the furnace temperature drops to room temperature, the pyrolysis product is added to 40 mL of potassium hydroxide solution (3 mol / L) and ultrasonicated at room temperature for 60 min; after the reaction, the insoluble solid is filtered out, and the remaining liquid is dried to obtain a water-soluble organic fertilizer, and the catalyst is recovered from the insoluble solid by magnetic separation.

[0055] Organic fertilizer yield = organic fertilizer mass / drug residue powder mass

[0056] After calculation, the yield of organic fertilizer obtained in Example 3 is 88.7%.

[0057] Example 4

[0058] An organic fertilizer prepared by directly pyrolyzing ginseng residue without adding a catalyst. The specific preparation steps are as follows:

[0059] (1) Dry, crush and sieve the ginseng residue to obtain 200-mesh residue powder; put 10 g of the residue powder into a tubular furnace, heat it at a rate of 5°C / min, keep it at 350°C for 2 h in a nitrogen atmosphere, and cool it naturally;

[0060] (2) After the reaction is completed and the furnace temperature drops to room temperature, the pyrolysis product is added to 50 mL of potassium hydroxide solution (3 mol / L) and ultrasonicated at room temperature for 60 min; after the reaction, the insoluble solid is filtered out, and the remaining liquid is dried to obtain a water-soluble organic fertilizer, and the catalyst is recovered from the insoluble solid by magnetic separation.

[0061] Organic fertilizer yield = organic fertilizer mass / drug residue powder mass

[0062] After calculation, the yield of organic fertilizer obtained in Example 4 was 24.12%.

[0063] Comparative Example 1

[0064] Comparative Example 1 uses commercial CoFe2O4 as a catalyst to convert Chinese medicine residue into Chinese herbal medicine organic fertilizer. The specific preparation steps are as follows:

[0065] (1) Drying, crushing and sieving ginseng residue to obtain 200-mesh residue powder; taking 0.1 g of commercial CoFe2O4 catalyst and 10 g of the residue powder obtained in step (1) and mixing them evenly; placing the mixture in a tubular furnace, heating at a rate of 5°C / min, keeping the temperature at 350°C in a nitrogen atmosphere for 2 h, and cooling naturally;

[0066] (2) After the reaction is completed and the furnace temperature drops to room temperature, the pyrolysis product is added to 50 mL of potassium hydroxide solution (3 mol / L) and ultrasonicated at room temperature for 60 min; after the reaction, the insoluble solid is filtered out, and the remaining liquid is dried to obtain a water-soluble organic fertilizer, and the catalyst is recovered from the insoluble solid by magnetic separation.

[0067] After calculation, the yield of organic fertilizer obtained by catalytic pyrolysis of ginseng residue using commercial CoFe2O4 in Comparative Example 1 was 37.8%.

[0068] In summary, Examples 1-4 and Comparative Example 1 reflect that the cobalt-iron catalyst prepared by the present invention has a significant effect on catalytic conversion of traditional Chinese medicine residues into Chinese herbal medicine organic fertilizer.

[0069] The following are some preferred conditions for the method of converting Chinese medicine residue into water-soluble organic fertilizer for Chinese herbal medicine using cobalt-iron catalyst: in step (1), the molar ratio of cobalt salt to iron salt is 1:0.5, 1:1, 1:1.5, 1:2, 1:2.5 or 1:3; the volume ratio of ethylene glycol to water is 1:1, 1:2, 1:3, 1:4, 1:5 or 1:10; the reaction temperature is 20°C, 25°C, 35°C, 45°C, 50°C, 60°C or 70°C. In step (2), the mass ratio of cobalt-iron catalyst to Chinese medicine residue powder is 1:10, 1:20, 1:30, 1:40, 1:50 or 1:100.

Claims

1. A method for converting Chinese medicine residues into Chinese herbal medicine organic fertilizer using a cobalt-iron catalyst, characterized in that: The steps include: (1) Synthesis of cobalt-iron catalyst: adding an aqueous solution of oxalate to a mixed solution containing cobalt salt and iron salt to react, collecting the precipitated product after the reaction is completed, washing, drying, and calcining to obtain a cobalt-iron catalyst; (2) mixing the Chinese medicine residue powder with the cobalt-iron catalyst obtained in step (1), introducing protective gas for pyrolysis; (3) adding the pyrolysis product to an alkaline solution for reaction, filtering out the solid residue after the reaction is completed, and drying the remaining liquid to obtain a Chinese herbal organic fertilizer; The oxalate described in step (1) is one or more of sodium oxalate, potassium oxalate, calcium oxalate, lithium oxalate, potassium iron oxalate, magnesium oxalate, and ammonium oxalate; the molar ratio of cobalt salt to iron salt is 1:0.5-1:3; the concentration of cobalt salt and iron salt is 0.5-4 mol / L; the concentration of oxalate is 0.1-1 mol / L; the reaction temperature is 20-70°C; the calcination temperature is 400-700°C, and the calcination time is 3±1h; The mass ratio of the cobalt-iron catalyst to the Chinese medicine slag powder in step (2) is 1:10-1:100; the pyrolysis temperature is 200-550° C., and the pyrolysis time is 60-300 min; The concentration of the alkaline solution in step (3) is 1 to 5 mol / L; the ratio of the pyrolysis product to the alkaline solution is 1 g:2 mL to 1 g:10 mL.

2. The method according to claim 1, characterized in that: The cobalt salt in step (1) is one or more of cobalt sulfate, cobalt nitrate and cobalt chloride; The iron salt is one or more of ferric sulfate, ferrous sulfate, ferric nitrate, ferrous nitrate and ferric chloride; The solvents of the mixed solution are ethylene glycol and water.

3. The method according to claim 2, characterized in that: The volume ratio of ethylene glycol to water in step (1) is 1:1-1:10; the drying temperature in step (1) is 80±20°C, and the drying time is 12±4h.

4. The method according to claim 1, characterized in that: The mesh size of the Chinese medicinal residue powder in step (2) is 200-400 mesh.

5. The method according to claim 4, characterized in that The Chinese medicinal residue described in step (2) is the residue extracted from Chinese medicinal materials; the Chinese medicinal materials are one or more of licorice, red ginseng, Corydalis yanhusuo, chrysanthemum, white peony root, atractylodes macrocephala, tangerine peel, pinellia, costusroot, poria, salvia miltiorrhiza, astragalus, ginseng, angelica, and codonopsis.

6. The method according to claim 1, characterized in that The protective gas in step (2) is one or more of nitrogen, hydrogen, carbon dioxide or argon.

7. The method according to claim 6, characterized in that The pyrolysis method described in step (2) is one-step pyrolysis or segmented pyrolysis.

8. The method according to claim 1, characterized in that: The reaction conditions described in step (3) are ultrasonication at room temperature for 30 to 120 min.

9. The method according to claim 1, characterized in that: The alkali solution in step (3) is one or more of a calcium hydroxide aqueous solution, an ammonia aqueous solution, a potassium hydroxide aqueous solution, and a sodium hydroxide aqueous solution.

10. A Chinese herbal medicine organic fertilizer prepared by the method according to any one of claims 1 to 9.

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