High-phosphorus carbon-based stability fertilizer and preparation method thereof
The preparation of high-phosphorus biochar-based stable fertilizer by blending and crystallization solves the problem of insufficient contact between biochar and fertilizer, achieves uniform nutrient distribution and improves nitrogen fertilizer utilization, and is suitable for improving specific soil environments.
Patent Information
- Application Number
- CN202510078877.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-17
- Publication Date
- 2026-02-10
- Estimated Expiration
- 2045-01-17
AI Technical Summary
In traditional carbon-based fertilizer preparation processes, biochar and fertilizer are difficult to fully react and react, and the preparation cost is high and the process is complicated, resulting in uneven nutrient distribution and low utilization rate.
A high-phosphorus carbon-based stable fertilizer was prepared by blending and crystallization. Phosphoric acid, urea, biochar and N-n-butylthiophosphate triamine were mixed to form a uniformly distributed carbon-based fertilizer, and urease inhibitors were added to delay nitrogen conversion and release.
It achieves full contact and reaction between biochar and fertilizer, resulting in uniform nutrient distribution, improved nitrogen fertilizer utilization, and a simple preparation process, making it suitable for specific environments such as saline-alkali land and other obstacle soils.
Smart Images
Figure CN119638519B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of fertilizer technology, and particularly relates to a high-phosphorus carbon-based stable fertilizer and its preparation method. Background Technology
[0002] Food security is inextricably linked to national security and is crucial to national stability and development. Fertilizers, as the "food of food," play an irreplaceable role in agricultural crop production. Results from over 5,000 fertilizer efficiency trials conducted by my country's National Fertilizer Testing Network in the 1980s also demonstrated that the rational application of fertilizers to rice, wheat, and corn resulted in an average yield increase of 48% compared to the control group without fertilizer. New types of fertilizers, such as coated slow-release fertilizers, are considered one effective way to address these issues.
[0003] Biochar is a porous, stable, and carbon-rich product obtained by high-temperature pyrolysis of agricultural and forestry waste and other biomass under oxygen-limited conditions. Due to its unique physicochemical properties and structure, biochar can improve soil physicochemical properties, enhance soil water retention capacity, and reduce nutrient leaching. However, the limited nutrient content of biochar means that applying biochar alone cannot provide sufficient nutrients for crops. Therefore, it is generally prepared as a biochar-based fertilizer. Biochar-based compound / blended fertilizers are typically made by mixing biochar with chemical fertilizers (nitrogen, phosphorus, potassium fertilizers, etc.), organic fertilizers (such as livestock manure, straw, etc.), and other possible components (such as trace elements, bioactive substances, etc.) in a certain proportion using chemical and / or physical methods. Biochar has well-developed pores, a large specific surface area, and abundant functional groups, giving it adsorption properties and the ability to adsorb nutrients. Its rich porous structure reduces the contact between embedded nutrients and water and soil, thus making biochar an excellent fertilizer carrier, providing slow-release of fertilizer nutrients and improving fertilizer utilization. Biochar-based fertilizers, made by mixing biochar with organic / inorganic fertilizers, have been proven to have a positive effect on soil physicochemical properties and crop growth and development. Currently, biochar-based fertilizers are receiving increasing global attention due to their advantages in improving soil physicochemical properties, remediating environmental pollution, regulating nutrient release rates, and enhancing fertilizer utilization. Traditional biochar-based fertilizer preparation technologies mainly include blending, coating, mixed granulation, solid-liquid adsorption, and co-thermal decomposition. However, biochar-based fertilizers prepared using traditional processes suffer from drawbacks such as difficulty in achieving sufficient contact and reaction between biochar and fertilizer, high preparation costs, and cumbersome preparation processes. Summary of the Invention
[0004] In view of this, the purpose of this invention is to provide a high-phosphorus carbon-based stable fertilizer and its preparation method. The high-phosphorus carbon-based stable fertilizer is prepared by blending and crystallization, which enables sufficient contact and reaction between biochar and fertilizer. The preparation process is simple, and the resulting carbon-based fertilizer has a uniform nutrient distribution. Furthermore, the addition of the urease inhibitor N-n-butylthiophosphate triamine can improve the nitrogen fertilizer utilization rate.
[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:
[0006] This invention provides a high-phosphorus carbon-based stabilized fertilizer, comprising the following components in parts by weight:
[0007] 110-120 parts phosphoric acid, 50-60 parts urea, 20-50 parts biochar, and 0.3-0.8 parts N-n-butyl thiophosphate triamine.
[0008] Preferably, the phosphoric acid is wet-process phosphoric acid, and the mass fraction of the phosphoric acid is 70-80%.
[0009] This invention also provides a method for preparing the aforementioned high-phosphorus carbon-based stabilized fertilizer, comprising the following steps:
[0010] 1) Phosphoric acid and urea are mixed and reacted to produce urea phosphate;
[0011] 2) React urea phosphate and biochar to obtain product A;
[0012] 3) React product A with N-n-butyl thiophosphate triamine, crystallize, and dry to obtain a high-phosphorus carbon-based stable fertilizer.
[0013] Preferably, the biochar is obtained by high-temperature pyrolysis of corn stalks, wherein the high-temperature pyrolysis temperature is 400-500℃ and the high-temperature pyrolysis time is 2-6 hours.
[0014] Preferably, the reaction temperature in step 1) is 70-75°C, and the reaction time is 30-40 min.
[0015] Preferably, the reaction temperature in step 2) is 70-75°C, and the reaction time is 30-50 min.
[0016] Preferably, the reaction temperature in step 3) is 70-75°C, and the reaction time is 10-30 min.
[0017] Preferably, the crystallization temperature in step 3) is 24–28°C, and the crystallization time is 18–30 h.
[0018] Preferably, the drying temperature in step 3) is 50-60°C, and the drying time is 12-36 hours.
[0019] Compared with the prior art, the present invention has the following beneficial effects:
[0020] This invention employs a blending crystallization method to prepare biochar-based fertilizer, which allows for thorough contact and reaction between biochar and its components, resulting in a uniform nutrient distribution in the formed fertilizer. Furthermore, there is no nutrient loss due to volatilization during the fertilizer preparation process, and the actual nutrient content matches the theoretically calculated nutrient content.
[0021] The biochar-based fertilizer prepared by this invention allows nutrients to be fully loaded onto the biochar, slowing down the rate of nutrient release and leaching. Furthermore, the addition of the urease inhibitor N-n-butylthiophosphate triamine further delays nitrogen conversion and release, improving nitrogen fertilizer utilization. This fertilizer product combines the slow-release properties of stable fertilizers with the functionality of biochar, making it a slow-release nitrogen functional fertilizer.
[0022] The carbon-based fertilizer prepared by this invention is acidic and can be applied as a special functional fertilizer in specific environments, such as saline-alkali land and other obstacle soils. Attached Figure Description
[0023] Figure 1 The difference in urea residue is the percentage of high-phosphorus carbon-based stable fertilizers prepared in different embodiments. Detailed Implementation
[0024] This invention provides a high-phosphorus carbon-based stabilized fertilizer, comprising the following components in parts by weight:
[0025] 110-120 parts phosphoric acid, 50-60 parts urea, 20-50 parts biochar, and 0.3-0.8 parts N-n-butyl thiophosphate triamine.
[0026] In this invention, the amount of phosphoric acid is preferably 102-115 parts, the phosphoric acid is preferably wet-process phosphoric acid, and the mass fraction of the phosphoric acid is preferably 70-80%, more preferably 72-78%; the amount of urea is preferably 52-58 parts; the amount of biochar is preferably 25-45 parts; and the amount of N-n-butylthiophosphate triamine is preferably 0.4-0.7 parts.
[0027] This invention also provides a method for preparing the aforementioned high-phosphorus carbon-based stabilized fertilizer, comprising the following steps:
[0028] 1) Phosphoric acid and urea are mixed and reacted to produce urea phosphate;
[0029] 2) React urea phosphate and biochar to obtain product A;
[0030] 3) React product A with N-n-butyl thiophosphate triamine, crystallize, and dry to obtain a high-phosphorus carbon-based stable fertilizer.
[0031] In this invention, the biochar is obtained by high-temperature pyrolysis of corn stalks. The corn stalks are cut into segments before high-temperature pyrolysis, and the length of the segments is preferably 1-3 cm, more preferably 1.5-2.5 cm. The temperature of the high-temperature pyrolysis is preferably 400-500℃, more preferably 420-480℃. The time of the high-temperature pyrolysis is preferably 2-6 h, more preferably 3-5 h.
[0032] In this invention, phosphoric acid and urea are mixed and reacted to generate urea phosphate. The phosphoric acid is preheated before the reaction, and the reaction temperature is preferably 70-75°C, more preferably 71-74°C; the reaction time is preferably 30-40 min, more preferably 32-38 min.
[0033] In this invention, urea phosphate and biochar are reacted to obtain product A. The reaction temperature is preferably 70–75°C, more preferably 71–74°C; the reaction time is preferably 30–50 min, more preferably 35–45 min.
[0034] In this invention, product A is reacted with N-n-butylthiophosphate triamine, crystallized, and dried to obtain a high-phosphorus carbon-based stable fertilizer. The reaction temperature is preferably 70–75°C, more preferably 71–74°C; the reaction time is preferably 10–30 min, more preferably 15–25 min; the crystallization temperature is preferably 24–28°C, more preferably 25–27°C; the crystallization time is preferably 18–30 h, more preferably 21–27 h; the drying temperature is preferably 50–60°C, more preferably 50–60°C; and the drying time is preferably 12–36 h, more preferably 18–30 h.
[0035] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.
[0036] Example 1
[0037] A high-phosphorus carbon-based stable fertilizer is composed of the following components in parts by weight: 113.5 parts of 75% wet-process phosphoric acid, 53 parts of urea, 24.5 parts of biochar, and 0.5 parts of N-n-butyl thiophosphate triamine.
[0038] Its preparation method is as follows:
[0039] S1. First, take the corn stalks, wash and dry them, then cut them into 2cm pieces with a chaff cutter. Heat them slowly to 450℃ and pyrolyze them for 4 hours. After cooling and grinding, sieve them and put them into self-sealing bags to seal them as biochar raw materials for later use.
[0040] S2. Set the water bath to 72.5℃, add 113.5 parts of 75% wet-process phosphoric acid to the reactor for preheating, and then add 53 parts of urea and react for 35 minutes.
[0041] After the S3 and S2 reactions are completed, 24.5 parts of the biochar prepared in S1 are added to the reactor and the reaction is continued at 72.5℃ for 35 minutes.
[0042] After the reactions in S4 and S3 are completed, add 0.5 parts of the urease inhibitor N-n-butyl thiophosphate triamine and react at 72.5℃ for 15 min.
[0043] S5. Pour the reaction product into a crystallizing dish and crystallize at room temperature for 24 hours. Then, place it in an oven at 55°C for 24 hours to obtain a high-phosphorus carbon-based stable fertilizer.
[0044] Example 2
[0045] A high-phosphorus carbon-based stable fertilizer is composed of the following components in parts by weight: 113.5 parts of 75% wet-process phosphoric acid, 53 parts of urea, 34.5 parts of biochar, and 0.5 parts of N-n-butyl thiophosphate triamine.
[0046] Its preparation method is as follows:
[0047] S1. First, take the corn stalks, wash and dry them, then cut them into 2cm pieces with a chaff cutter. Heat them slowly to 450℃ and pyrolyze them for 4 hours. After cooling and grinding, sieve them and put them into self-sealing bags to seal them as biochar raw materials for later use.
[0048] S2. Set the water bath to 72.5℃, add 113.5 parts of 75% wet-process phosphoric acid to the reactor for preheating, then add 53 parts of urea and continue the reaction for 35 minutes.
[0049] After the S3 and S2 reactions are completed, 34.5 parts of the biochar prepared in S1 are added to the reactor and the reaction is continued at 72.5℃ for 35 minutes.
[0050] After the reactions in S4 and S3 are completed, add 0.5 parts of the urease inhibitor N-n-butyl thiophosphate triamine and react at 72.5℃ for 15 min.
[0051] S5. Pour the reaction product into a crystallizing dish and crystallize at room temperature for 24 hours. Then, place it in an oven at 55°C for 24 hours to obtain a high-phosphorus carbon-based stable fertilizer.
[0052] Example 3
[0053] A high-phosphorus carbon-based stable fertilizer is composed of the following components in parts by weight: 113.5 parts of 75% wet-process phosphoric acid, 53 parts of urea, 46 parts of biochar, and 0.5 parts of N-n-butyl thiophosphate triamine.
[0054] Its preparation method is as follows:
[0055] S1. First, take the corn stalks, wash and dry them, then cut them into 2cm pieces with a chaff cutter. Heat them slowly to 450℃ and pyrolyze them for 4 hours. After cooling and grinding, sieve them and put them into self-sealing bags to seal them as biochar raw materials for later use.
[0056] S2. Set the water bath to 72.5℃, add 113.5 parts of 75% wet-process phosphoric acid to the reactor for preheating, then add urea and continue the reaction for 35 minutes.
[0057] After the S3 and S2 reactions are completed, 46 parts of the biochar prepared in S1 are added to the reactor and the reaction is continued at 72.5℃ for 35 minutes.
[0058] After the reactions in S4 and S3 are completed, add 0.5 parts of the urease inhibitor N-n-butyl thiophosphate triamine and react at 72.5℃ for 15 min.
[0059] S5. Pour the reaction product into a crystallizing dish and crystallize at room temperature for 24 hours. Then, place it in an oven at 55°C for 24 hours to obtain a high-phosphorus carbon-based stable fertilizer.
[0060] Experimental Example 1
[0061] Determination of Nutrient Content and Biochar Content in High-Phosphorus Carbon-Based Stabilized Fertilizers
[0062] The P2O5 and N contents of the fertilizer were determined by a fully automated intermittent chemical analyzer and a continuous flow analyzer after digestion with H2SO4-H2O2. The urea content was determined by referring to the urea determination method in the national standard for stable fertilizers (GB / T35113-2017). The total nutrient content was the sum of the P2O5 and N contents. The biochar content was the biochar mass / (mass of pure phosphoric acid + mass of urea + mass of biochar) during the preparation of the biochar-based fertilizer.
[0063] Because biochar itself carries a variety of mineral elements, such as K + Ca 2+ Mg 2+ Therefore, the prepared carbon-based fertilizer also contains other micronutrients beneficial to plant growth. Since these elements are not the main focus of this invention, they are not listed in Table 1, but it should be noted that they are present in the prepared carbon-based fertilizer.
[0064] Experimental results are shown in Table 1.
[0065] Table 1 Nutrient content and biochar content in high-phosphorus carbon-based stabilized fertilizers
[0066] deal with <![CDATA[P2O5 content]]> N content Urea content Total nutrient content Biochar content Example 1 37％ 15％ 29％ 52％ 15％ Example 2 35％ 14％ 27％ 49％ 20％ Example 3 33％ 13％ 25％ 46％ 25％
[0067] As shown in Table 1, the high-phosphorus carbon-based stable fertilizer prepared by this invention has no nutrient volatilization loss, and the actual nutrient content is equal to the theoretically calculated nutrient content.
[0068] Experiment Example 2
[0069] Determination of urea residue variation rate in high-phosphorus carbon-based stabilized fertilizers
[0070] The method for determining the urea residue difference rate is based on the national standard GB / T 35113-2017 for stabilized fertilizers.
[0071] Experimental results: such as Figure 1 As shown. By Figure 1 It can be seen that the urea residue difference rate decreases with the increase of biochar addition. This is because the larger the biochar addition, the larger the specific surface area provided by the biochar in the biochar-based fertilizer, which provides more reaction sites for urease and urea, thus leading to the decomposition of more urea and a smaller urea residue difference rate.
[0072] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A method for preparing a high-phosphorus carbon-based stabilized fertilizer, characterized in that, The high-phosphorus carbon-based stabilized fertilizer comprises the following components in parts by weight: 110-120 parts phosphoric acid, 50-60 parts urea, 20-50 parts biochar, and 0.3-0.8 parts N-n-butyl thiophosphate triamine; wherein the phosphoric acid is wet-process phosphoric acid, and the mass fraction of the phosphoric acid is 70-80%. A method for preparing high-phosphorus carbon-based stabilized fertilizer includes the following steps: 1) Mix phosphoric acid and urea, react to produce urea phosphate; the reaction temperature is 70~75℃, and the reaction time is 30~40min; 2) React urea phosphate and biochar to obtain product A; the reaction temperature is 70~75℃ and the reaction time is 30~50min; 3) React product A with N-n-butylthiophosphate triamine, crystallize, and dry to obtain a high-phosphorus carbon-based stable fertilizer; The reaction temperature is 70~75℃, and the reaction time is 10~30 min; The crystallization temperature is 24~28℃, and the crystallization time is 18~30h.
2. The preparation method according to claim 1, characterized in that, Biochar is obtained by high-temperature pyrolysis of corn stalks. The pyrolysis temperature is 400~500℃ and the pyrolysis time is 2~6h.
3. The preparation method according to claim 1, characterized in that, Step 3) The drying temperature is 50~60℃ and the drying time is 12~36h.
Citation Information
Patent Citations
Nitrogen fertilizer synergist and application thereof
CN105367207A