CN104355903A - Method for preparing biochar based slow release fertilizers by utilizing Chinese torreya shells - Google Patents

Abstract

A method for preparing bio-carbon-based slow-release fertilizers using Torreya husks, which uses Torreya husks as raw materials, prepares modified biochar through anaerobic pyrolysis, and then mixes cow dung biogas residues, chemical fertilizers, urease inhibitors and nitrification Inhibitors, etc. are mixed to prepare high-efficiency slow-release fertilizers. The slow-release fertilizer prepared by the invention has simple production process, easy-to-obtain raw materials, and low production cost. It can not only effectively improve the utilization rate of nitrogen, phosphorus, and potassium, reduce nutrient loss, but also improve soil quality, improve the quality of agricultural products, and benefit the agricultural ecosystem. benign development.

Description

A method for preparing biochar-based slow-release fertilizer by using Torreya husk

technical field

The invention relates to the technical field of preparation of biochar-based fertilizers, in particular to a method for preparing biochar-based slow-release fertilizers from Torreya husks.

Background technique

According to statistics, the annual use of chemical fertilizers in China has reached 42.14 million tons, with an average of 368 kg/hm ² , and the structure of chemical fertilizers is still unreasonable in the process of application, and the utilization rate of chemical fertilizers is extremely low. According to data, the average utilization rate of nitrogen fertilizer in my country is only 30% to 40%, phosphate fertilizer is only 10% to 20%, and potassium fertilizer is only 35% to 50%. The loss of chemical fertilizers not only increases production costs, but also causes eutrophication of lakes, reservoirs, rivers and other water bodies, changes in soil properties, decline in productivity, and decline in the quality of agricultural products. Therefore, reducing non-point source pollution from agricultural chemical fertilizers, developing ecological agriculture, and improving the ecological environment are important tasks in current agricultural production. For this reason, a lot of research work has been carried out at home and abroad, and various types of slow-release fertilizers have been developed, which have greatly reduced the non-point source pollution of chemical fertilizers.

Slow-release fertilizers, also known as long-acting fertilizers or controlled-release fertilizers, refer to the slow release of effective nutrients due to changes in chemical composition or coating of semi-permeable or impermeable substances on the surface to maintain long-term fertilizer effects. The most important feature of slow-release nitrogen fertilizer is that it can control its release rate, and gradually decompose after being applied to the soil, and gradually be absorbed and utilized by crops, so that the nutrients in the fertilizer can meet the different needs of crops in each growth stage throughout the growth period. After one application, The fertilizer effect can be maintained for several months to more than a year. The application of slow-release/controlled-release fertilizers can not only reduce production costs, but also reduce non-point source pollution from agricultural chemical fertilizers, and take advantage of the sustainable development of agriculture.

Biochar is a solid substance left after biomass material is pyrolyzed under anoxic or oxygen-limited conditions to remove oil and gas from the biomass. Biochar has excellent adsorption properties and can directly adsorb pollutants in wastewater; after soil application, it can also improve soil physical and chemical properties, reduce nutrient loss, promote crop growth, adsorb and fix soil pollutants, and increase soil carbon pools The role of emission reduction. Therefore, biochar has become one of the research hotspots in the field of environmental and agricultural sciences in recent years.

Contents of the invention

Another object of the present invention is to provide the preparation method and application method of the biochar-based slow-release fertilizer.

In order to achieve the purpose of the present invention, the present invention provides a preparation method of biochar-based slow-release fertilizer, which mainly includes biochar, organic matter and chemical fertilizer, and the biochar is prepared by low-temperature carbonization modification of Torreya husk.

The biological carbon-based slow-release fertilizer provided by the invention, its raw material comprises the composition of following mass ratio:

Modified biochar product: 25-40

Cow dung biogas residue: 25～35

Fertilizer: 30~40

Mixed solution of urease inhibitor and nitrification inhibitor: 2 to 5

Adhesive: 5-10

The mass ratio of the biochar to biogas residue, fertilizer, urease inhibitor and nitrification inhibitor mixed solution and binder is (25-40): (25-35): (30-40): (2-5 ): (5-10), preferably 32:27:33:3:5.

The biochar-based slow-release fertilizer has total nutrients (N+P ₂ O ₅ +K ₂ O)≧20%, biochar≧30%, and organic matter≧30%.

In addition, the present invention firstly provides a method for preparing the above-mentioned biochar-based slow-release fertilizer, comprising the following specific steps:

(1) Crush and sieve the collected torreya husks.

(2) Add dilute hydrochloric acid to the crushed torreya husk, stir and mix well, seal and let stand for 24 hours, then add cesium nitrate solution, mix and seal and let stand for 12 hours, then air dry naturally.

(3) Put the above-mentioned treated biomass in a porcelain crucible for compaction, cover the lid for anaerobic pyrolysis; after the pyrolysis reaction is completed, take out the crucible after cooling to room temperature.

(4) Mix the biochar prepared above with a certain concentration of H ₂ O ₂ , shake it in a shaker for 24 hours, take it out, wash it with distilled water and dry it to obtain biochar with high adsorption performance.

(5) Put the above-prepared biochar into an airtight container, add a certain amount of concentrated ammonia water and platinum nitrate solution, heat it for reaction, and take it out after 3-10 hours of reaction. During the reaction, the pressure of the reaction vessel was adjusted so as to maintain it at 5-15 standard atmospheres.

(6) With the above-mentioned modified biochar as the main body, add a certain amount of biogas residue, chemical fertilizers (nitrogen fertilizer, phosphate fertilizer, potassium fertilizer), urease inhibitor/nitration inhibitor mixture, binder, etc., in organic and inorganic fertilizers The granulated material is granulated in the granulator, and the granulated material is dried in the dryer, and the bio-carbon-based slow-release fertilizer is obtained after cooling.

In order to ensure an oxygen-deficient environment and pyrolysis effect during pyrolysis, the particle size of the biomass raw material crushed in the step 1 is 20-100 mesh.

In the step 2, the concentration of dilute hydrochloric acid is 0.5-2.5mol/L, and the concentration of cesium nitrate solution is 0.05-1.5mol/L.

In the step 3, the biomass pyrolysis temperature is 400-700°C, the pyrolysis time is 60-300min, and the heating rate is 5-15°C/min.

The concentration of H ₂ O ₂ in step 4 is 1-10%.

In order to improve the reaction effect between biochar and ammonia water, increase the combined ammonia content in the modified biochar functional group, the concentration of concentrated ammonia water in the step 5 is 5%-28%, and the concentration of platinum nitrate solution is 0.02-1.0mol/L, During the reaction, the pressure of the reaction vessel was maintained at 5-15 standard atmospheres.

In order to improve the utilization rate of ammonia water in step 5, when adjusting the pressure of the reaction vessel described in step 5, the outlet of the pressure reducing valve can be placed in water, and the aqueous solution after absorbing ammonia gas can be used to prepare fertilizer.

In the step 6, the urease inhibitor is hydroquinone, copper sulfate, o-phenylphosphoric diamide (PPD), catechol, thiophosphoric triamide (NBPT), thiourea or other solid state at normal temperature Water-soluble materials with urease inhibitory effect; nitrification inhibitors are 2-chloro-6-(trichlorotoluene)pyridine (also known as xipyridine), amidinothiourea (ASU), dicyandiamide (DCD) , 2-methyl-4,6-bis(trichlorotoluene)-s-triazine (MDCT), 2-sulfathiazole (ST), etc. or other water-soluble nitrification inhibitors that exist in solid state at room temperature Material. The mixed solution of urease inhibitor and nitrification inhibitor in the step 6 is a mixed solution of urease inhibitor and nitrification inhibitor in a mass ratio of 1:1.

The biogas residue in step 6 is the cow dung solid left after biogas fermentation treatment (naturally air-dried and crushed to 20-50 mesh before use), and the nitrogen fertilizer is one or more of urea, ammonium carbonate, ammonium nitrate, and ammonium chloride. The phosphate fertilizer is one or more of calcium superphosphate, heavy superphosphate, dicalcium phosphate, calcium magnesium phosphate fertilizer, defluorinated phosphate fertilizer, phosphate rock powder fertilizer, slag phosphate fertilizer, and steel slag phosphate fertilizer. The potassium fertilizer is potassium chloride, sulfuric acid One or more of potassium, potassium dihydrogen phosphate, potassium rock salt, potassium magnesium salt, and the binder is bentonite.

The present invention has following beneficial effect:

The invention uses modified biochar prepared from Torreya husk and cow dung biogas residue as raw materials to prepare the slow-release fertilizer, the production process is simple, the raw materials are easy to obtain, and the production cost is low.

Biochar has a strong adsorption capacity, which can delay the release rate of nutrients; the adsorption capacity of modified biochar is further enhanced, and a large amount of amino groups are added in the modification reaction process, which further enhances the slow-release characteristics of fertilizers; at the same time , The cow dung biogas residue in the fertilizer also has a strong adsorption capacity and can also delay the release of nutrients.

Biochar-based slow-release fertilizers can not only effectively increase the utilization rate of nitrogen, phosphorus and potassium, reduce nutrient loss, but also improve soil quality, improve the quality of agricultural products, and benefit the healthy development of agricultural ecosystems.

Detailed ways

The present invention is specifically described by the following examples. It is necessary to point out that the following examples are only used to further illustrate the present invention, and cannot be interpreted as limiting the protection scope of the present invention. Those skilled in the art can according to the above-mentioned content Some non-essential improvements and adjustments are made to the present invention.

Example 1

1. Preparation of biochar-based slow-release fertilizer

The raw materials of the biochar-based slow-release fertilizer include the following components by mass ratio:

Modified biochar 30, cow dung biogas residue (30 mesh) 30, chemical fertilizer 31, a mixed solution of hydroquinone and cepiryl in a mass ratio of 1:1 3, bentonite 6.

Among them, the chemical fertilizer is to mix urea, superphosphate and potassium sulfate in a mass ratio of 1:2:2.

The preparation method: mix the ingredients according to the above ratio, extrude and granulate in a mold, sieve the granulated material, put it in an oven for drying, and obtain the bio-carbon-based slow-release fertilizer after cooling.

2. Preparation method of modified biochar:

(1) Crush the collected torreya husks through an 80-mesh sieve.

(2) Take 100g of the above pulverized Torreya husk, add 25ml of 1.0mol/L dilute hydrochloric acid, stir and mix, seal and let stand for 24h, then add 2ml of 0.1mol/L cesium nitrate solution, mix evenly, seal and let stand for 12h, and air dry naturally.

(3) Put the above treated biomass in a porcelain crucible for compaction, put the lid on and perform anaerobic pyrolysis at 600°C for 3 hours, with a heating rate of 10°C/min; after the pyrolysis reaction is completed, cool the crucible Remove from room temperature.

(4) Mix the above prepared biochar with 100ml of 8% H ₂ O ₂ , shake it in a shaker for 24 hours, take it out, wash it with distilled water and dry it to obtain biochar with high adsorption performance.

(5) Put the above-prepared biochar into an airtight container, add 25ml of 25% ammonia water and 1ml of 0.5mol/L platinum nitrate solution, heat for reaction, and take it out after 2 hours of reaction. During the reaction, the pressure of the reaction vessel was adjusted to maintain 8 standard atmospheres.

Example 2

1. Preparation of biochar-based slow-release fertilizer

The raw materials of the biochar-based slow-release fertilizer include the following components by mass ratio:

Modified biochar 32, cow dung biogas residue (30 mesh) 30, chemical fertilizer 33, a mixed solution of hydroquinone and cepiryl in a mass ratio of 1:1 3, bentonite 6.

Among them, the chemical fertilizer is to mix urea, superphosphate and potassium sulfate in a mass ratio of 1:2:2.

The preparation method: mix the ingredients according to the above ratio, extrude and granulate in a mold, sieve the granulated material, put it in an oven for drying, and obtain the bio-carbon-based slow-release fertilizer after cooling.

2. Preparation method of modified biochar:

(1) Crush the collected torreya husks through an 80-mesh sieve.

(2) Take 100g of the above pulverized Torreya husk, add 25ml of 1.0mol/L dilute hydrochloric acid, stir and mix, seal and let stand for 24h, then add 2ml of 0.1mol/L cesium nitrate solution, mix evenly, seal and let stand for 12h, and air dry naturally.

(3) Put the above treated biomass in a porcelain crucible for compaction, put the lid on and perform anaerobic pyrolysis at 600°C for 3 hours, with a heating rate of 10°C/min; after the pyrolysis reaction is completed, cool the crucible Remove from room temperature.

(4) Mix the above prepared biochar with 100ml of 8% H ₂ O ₂ , shake it in a shaker for 24 hours, take it out, wash it with distilled water and dry it to obtain biochar with high adsorption performance.

(5) Put the above-prepared biochar into an airtight container, add 25ml of 25% ammonia water and 1ml of 0.5mol/L platinum nitrate solution, heat for reaction, and take it out after 2 hours of reaction. During the reaction, the pressure of the reaction vessel was adjusted to maintain 8 standard atmospheres.

Example 3

1. Preparation of biochar-based slow-release fertilizer

The raw materials of the biochar-based slow-release fertilizer include the following components by mass ratio:

Modified biochar 32, cow dung biogas residue (30 mesh) 27, chemical fertilizer 33, a mixed solution of hydroquinone and cepiryl in a mass ratio of 1:1, 3, bentonite 5.

Among them, the chemical fertilizer is to mix urea, superphosphate and potassium sulfate in a mass ratio of 1:2:2.

The preparation method: mix the ingredients according to the above ratio, extrude and granulate in a mold, sieve the granulated material, put it in an oven for drying, and obtain the bio-carbon-based slow-release fertilizer after cooling.

2. Preparation method of modified biochar:

(1) Crush the collected torreya husks through an 80-mesh sieve.

(2) Take 100g of the above pulverized Torreya husk, add 25ml of 1.0mol/L dilute hydrochloric acid, stir and mix, seal and let stand for 24h, then add 2ml of 0.1mol/L cesium nitrate solution, mix evenly, seal and let stand for 12h, and air dry naturally.

(3) Put the above treated biomass in a porcelain crucible for compaction, put the lid on and perform anaerobic pyrolysis at 600°C for 3 hours, with a heating rate of 10°C/min; after the pyrolysis reaction is completed, cool the crucible Remove from room temperature.

(4) Mix the above prepared biochar with 100ml of 8% H ₂ O ₂ , shake it in a shaker for 24 hours, take it out, wash it with distilled water and dry it to obtain biochar with high adsorption performance.

(5) Put the above-prepared biochar into an airtight container, add 25ml of 25% ammonia water and 1ml of 0.5mol/L platinum nitrate solution, heat for reaction, and take it out after 2 hours of reaction. During the reaction, the pressure of the reaction vessel was adjusted to maintain 8 standard atmospheres.

Example 4

1. Preparation of biochar-based slow-release fertilizer

The raw materials of the biochar-based slow-release fertilizer include the following components by mass ratio:

Modified biochar 30, cow dung biogas residue (30 mesh) 27, chemical fertilizer 30, a mixed solution of hydroquinone and cepiryl at a mass ratio of 1:1 3, bentonite 5.

Among them, the chemical fertilizer is to mix urea, superphosphate and potassium sulfate in a mass ratio of 1:2:2.

The preparation method: mix the ingredients according to the above ratio, extrude and granulate in a mold, sieve the granulated material, put it in an oven for drying, and obtain the bio-carbon-based slow-release fertilizer after cooling.

2. Preparation method of modified biochar:

(1) Crush the collected torreya husks through an 80-mesh sieve.

(2) Take 100g of the above pulverized Torreya husk, add 25ml of 1.0mol/L dilute hydrochloric acid, stir and mix, seal and let stand for 24h, then add 2ml of 0.1mol/L cesium nitrate solution, mix evenly, seal and let stand for 12h, and air dry naturally.

(3) Put the above treated biomass in a porcelain crucible for compaction, put the lid on and perform anaerobic pyrolysis at 600°C for 3 hours, with a heating rate of 10°C/min; after the pyrolysis reaction is completed, cool the crucible Remove from room temperature.

(4) Mix the above prepared biochar with 100ml of 8% H ₂ O ₂ , shake it in a shaker for 24 hours, take it out, wash it with distilled water and dry it to obtain biochar with high adsorption performance.

(5) Put the above-prepared biochar into an airtight container, add 25ml of 25% ammonia water and 1ml of 0.5mol/L platinum nitrate solution, heat for reaction, and take it out after 2 hours of reaction. During the reaction, the pressure of the reaction vessel was adjusted to maintain 8 standard atmospheres.

Example 5

1. Preparation of biochar-based slow-release fertilizer

The raw materials of the biochar-based slow-release fertilizer include the following components by mass ratio:

Modified biochar 30, cow dung biogas residue (30 mesh) 27, chemical fertilizer 32, a mixed solution of hydroquinone and cepiryl in a mass ratio of 1:1 3, bentonite 5.

Among them, the chemical fertilizer is to mix urea, superphosphate and potassium sulfate in a mass ratio of 1:2:2.

The preparation method: mix the ingredients according to the above ratio, extrude and granulate in a mold, sieve the granulated material, put it in an oven for drying, and obtain the bio-carbon-based slow-release fertilizer after cooling.

2. Preparation method of modified biochar:

(1) Crush the collected torreya husks through an 80-mesh sieve.

(2) Take 100g of the above pulverized Torreya husk, add 25ml of 1.0mol/L dilute hydrochloric acid, stir and mix, seal and let stand for 24h, then add 2ml of 0.1mol/L cesium nitrate solution, mix evenly, seal and let stand for 12h, then air dry naturally.

(3) Put the above treated biomass in a porcelain crucible for compaction, put the lid on and perform anaerobic pyrolysis at 600°C for 3 hours, with a heating rate of 10°C/min; after the pyrolysis reaction is completed, cool the crucible Remove from room temperature.

(4) Mix the above prepared biochar with 100ml of 8% H ₂ O ₂ , shake it in a shaker for 24 hours, take it out, wash it with distilled water and dry it to obtain biochar with high adsorption performance.

(5) Put the above-prepared biochar into an airtight container, add 25ml of 25% ammonia water and 1ml of 0.5mol/L platinum nitrate solution, heat for reaction, and take it out after 2 hours of reaction. During the reaction, the pressure of the reaction vessel was adjusted to maintain 8 standard atmospheres.

Example 6

Biochar-based slow-release fertilizer application test example:

Pot test:

1. There are two treatments in this experiment, namely the control group and the test group. The test adopts potted planting, the diameter of the pot is 30cm, the bottom diameter is 20cm, the height is 30cm, and the soil in each pot is 8kg. Common fertilization (5g of common compound fertilizer as base fertilizer) was used as the control, 5g of self-made slow-release fertilizer was used as the test group, rice was used as the test crop, and a 2-3cm water layer was maintained throughout the growth period after transplanting. Sowing in April, transplanting in May, 1 hole per pot, 1 seedling per hole. Each treatment was repeated three times.

2. Test results: The test results showed that the plants in the control group were harvested on September 2, with a plant biomass of 238g and grains of 102g; The period was delayed by 10-15 days compared with the control group. After harvest, the plant biomass was 5%-15% higher than that of the control group, and the grain yield was 2%-10% higher. After the plants were harvested, the soil was air-dried, and the analysis and testing found that the organic matter of the soil TN, TP, and TK in the test group was 25%-30%, 15%-23%, 16%-24%, and 23%-29% higher than that of the control soil.

Claims (8)

1. a kind of utilization Chinese torreya husk to prepare biochar-based slow-release fertilizer, is characterized in that, mainly comprises modified biochar, cow dung biogas residue, chemical fertilizer, urease inhibitor/nitrification inhibitor mixed solution, described modified biochar It is prepared by modifying the high-adsorption performance biochar of Torreya husk and ammonia water. 2. biological carbon-based slow-release fertilizer as claimed in claim 1, is characterized in that, the mass ratio of the mixed solution of described biochar and biogas residue, chemical fertilizer, urease inhibitor and nitrification inhibitor, binder is (25～ 40): (25~35): (30~40): (2~5): (5~10). 3. The biochar-based slow-release fertilizer according to claim 1, wherein the total nutrients (N+P ₂ O ₅ +K ₂ O)≧20% of the bio-carbon-based slow-release fertilizer, biochar≧30 %, organic matter≧30%. 4. modified biochar as claimed in claim 1 is made by the following method: (1) crush and sieve the collected torreya husk; (2) Add dilute hydrochloric acid to the above crushed husks, stir and mix well, seal and let stand for 24 hours, then add cesium nitrate solution, mix and seal and let stand for 12 hours, then air dry naturally; (3) Put the above-mentioned treated biomass in a porcelain crucible for compaction, cover the lid for anaerobic pyrolysis; after the pyrolysis reaction is completed, take out the crucible after cooling to room temperature; (4) Mix the above-prepared biochar with a certain concentration of H ₂ O ₂ , shake it in a shaker for 24 hours, take it out, wash it with distilled water and dry it to obtain biochar with high adsorption performance; (5) Put the biochar prepared above into an airtight container, add a certain amount of concentrated ammonia water and platinum nitrate solution, heat the reaction, and take it out after 3-10 hours of reaction; during the reaction, adjust the pressure of the reaction container to maintain it at 5 -15 standard atmospheres. 5. The preparation of the modified biochar according to claim 4, characterized in that the concentration of dilute hydrochloric acid in step 2 is 0.5-2.5mol/L, and the concentration of cesium nitrate solution is 0.05-1.5mol/L. 6. The preparation of modified biochar as claimed in claim 4, characterized in that, in the step 3, the biomass pyrolysis temperature is 400-700°C, the pyrolysis time is 60-300min, and the heating rate is 5-15°C/min . 7. The preparation of modified biochar according to claim 4, characterized in that the concentration of H ₂ O ₂ in step 4 is 1-10%. 8. The preparation of modified biochar as claimed in claim 5, is characterized in that, in the described step 5, the concentration of concentrated ammonia water is 5%-28%, and the concentration of platinum nitrate solution is 0.02-1.0mol/L, during the reaction, the reaction vessel The pressure is maintained at 5-15 standard atmospheres.