An organic water-soluble fertilizer with wood vinegar as the raw material and its preparation method

Abstract

The present invention relates to the technical field of organic fertilizers, and discloses an organic water-soluble fertilizer taking wood vinegar liquid as a raw material and a preparation method thereof. The organic water-soluble fertilizer is made from the following raw materials in parts by weight: 35 - 45 parts of purified wood vinegar liquid, 15 - 20 parts of potassium humate, 8 - 12 parts of compound amino acids, 5 - 8 parts of chelated medium and trace elements, 2 - 3 parts of synergist, 0.5 - 1 part of pH regulator, and 11 - 34.5 parts of deionized water. The purified wood vinegar liquid is obtained by subjecting the crude wood vinegar liquid of a biomass boiler to pretreatment, gradient distillation, and adsorption and impurity removal, wherein the acetic acid content is ≥12%, the tar content is ≤0.1%, the pH value is 3.5 - 4.0, and the density is 1.12 - 1.15 g / cm3; the compound amino acids are compounded from glycine, glutamic acid, and proline according to a mass ratio of 2:1:1, and the total amino acid content is ≥95%. The present invention not only solves the toxicity problem of direct application of wood vinegar liquid but also increases the concentration of effective components. At the same time, a small amount of phenolic substances retained during the distillation process and the chitosan oligosaccharide in the synergist act synergistically, increasing the control effect of the fertilizer on soil-borne diseases to more than 85%.

Description

Technical Field

[0001] This invention relates to the field of organic fertilizer technology, specifically to an organic water-soluble fertilizer made from wood vinegar and its preparation method. Background Technology

[0002] During the combustion process in biomass boilers, biomass pellets are carbonized at a low temperature of 260℃. The resulting steam is condensed in a cooling furnace to form wood vinegar. This wood vinegar has a complex composition, containing approximately 80% water and 20% organic matter. It is highly acidic and has an extremely high chemical oxygen demand (COD), and direct discharge would cause serious environmental pollution. Currently, the application of wood vinegar in agriculture is mostly limited to simple dilution and direct application. However, according to test data, crude wood vinegar contains only 7.46% acetic acid and 2.01% tar, and also contains toxic substances such as polycyclic aromatic hydrocarbons (PAHs). Direct application can easily lead to root burn in crops and imbalance in the soil microbial community. Furthermore, its effective component concentration is low and dispersed, making it difficult to meet the nutrient requirements of crops throughout their entire growth cycle when applied alone, thus limiting its promotion in large-scale agricultural production.

[0003] Current technologies for treating wood vinegar primarily focus on "wastewater harmlessness" or "single-component purification," lacking a systematic approach that integrates it with fertilizer functions. Some technologies use distillation to purify wood vinegar, but fail to consider the preservation of active ingredients and synergistic nutrient absorption after purification. Other methods simply mix wood vinegar with chemical fertilizers, but this fails to address the reaction and precipitation issues between the acidity of wood vinegar and nitrogen and phosphorus in the fertilizers, leading to decreased nutrient utilization and the continued toxicity of residual tar components to crops. Furthermore, traditional organic water-soluble fertilizers only provide nutrients and cannot simultaneously achieve soil disease control and water and fertilizer retention. In current agricultural production, problems such as soil acidification, frequent soil-borne diseases, and severe water and fertilizer loss coexist, urgently requiring a multifunctional organic water-soluble fertilizer that integrates "nutrient supply, soil improvement, and disease control."

[0004] Therefore, developing a method for preparing organic water-soluble fertilizer based on wood vinegar purification that balances safety and functionality can not only realize the resource utilization of wood vinegar, but also solve multiple technical defects of existing fertilizers, and has important economic and ecological value. Summary of the Invention

[0005] The purpose of this invention is to provide an organic water-soluble fertilizer using wood vinegar as a raw material and its preparation method in order to solve the above-mentioned problems.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An organic water-soluble fertilizer made from wood vinegar is composed of the following parts by weight: 35-45 parts purified wood vinegar, 15-20 parts potassium humate, 8-12 parts compound amino acids, 5-8 parts chelated trace elements, 2-3 parts synergist, 0.5-1 part pH adjuster, and 11-34.5 parts deionized water.

[0008] The purified wood vinegar is obtained from crude wood vinegar from a biomass boiler through pretreatment, gradient distillation, and adsorption purification. It contains acetic acid ≥12%, tar content ≤0.1%, pH 3.5-4.0, and density 1.12-1.15 g / cm³. 3 The compound amino acid is composed of glycine, glutamic acid, and proline in a mass ratio of 2:1:1, with a total amino acid content ≥95%; the chelated trace elements include 2-3 parts EDTA-Ca, 1-2 parts EDTA-Mg, 1-2 parts EDTA-Zn, and 0.5-1 parts boric acid, with a chelation degree ≥90%; the synergist is a mixture of 1-1.5 parts chitosan oligosaccharide and 0.1-0.2 parts brassinolide; the pH adjuster is food-grade sodium bicarbonate.

[0009] Preferably, the potassium humate is water-soluble potassium humate, wherein the humic acid content is ≥70% and the water-insoluble matter is ≤5%; the rotational viscosity (40℃) of the purified wood vinegar is 2.0-2.2 mPa・s and the particle size distribution Dv50 is ≤0.07μm.

[0010] Preferably, the detection indicators of the crude wood vinegar from the biomass boiler are: acetic acid 7.46%, formic acid 0.39%, propionic acid 0.19%, tar 2.01%, pH 2.84, and density 1.0653 g / cm³. 3 Particle size distribution: Dv10=0.020μm, Dv50=0.056μm, Dv90=0.200μm.

[0011] A method for preparing an organic water-soluble fertilizer using wood vinegar as a raw material includes the following steps:

[0012] S1: Wood vinegar pretreatment: Take crude wood vinegar from biomass boiler, add diatomaceous earth at 1%-2% of the crude wood vinegar mass, stir for 30-40 minutes at 40-45℃ and 300-400r / min, then filter through a 0.2μm precision plate and frame filter press at 0.3-0.5MPa pressure, and collect the filtrate to obtain pretreated wood vinegar;

[0013] S2: Gradient distillation purification of wood vinegar: The pretreated wood vinegar is passed into a vacuum distillation column and distilled in three stages. The first stage is distilled for 1.5-2 hours under vacuum of 0.06 MPa, temperature of 60-65℃, and reflux ratio of 1:2, and fraction I is discarded. The second stage is distilled for 2-2.5 hours under vacuum of 0.08 MPa, temperature of 85-90℃, and reflux ratio of 1:1, and fraction II is collected. The third stage is distilled for 1 hour under vacuum of 0.09 MPa, temperature of 110-115℃, and reflux ratio of 1:3, and the residue at the bottom of the column is discarded. 0.5%-1% of activated carbon by mass is added to fraction II, and the mixture is allowed to stand at 25-30℃ for 2-3 hours for adsorption, with stirring at 100 r / min every 30 minutes. The mixture is then filtered through a 0.1 μm microporous membrane to obtain purified wood vinegar.

[0014] S3: Raw material mixing and chelation reaction: Add deionized water to the reactor, heat to 50-55℃, add potassium humate and compound amino acids sequentially at 500-600 r / min, and stir for 20-25 minutes until completely dissolved; keep the stirring speed constant, add the chelated trace elements and heat to 60-65℃, and stir for 30-35 minutes; then add purified wood vinegar dropwise at a rate of 5-8 mL / min, adjusting the pH of the system to 5.0-5.5 with 10% sodium bicarbonate solution during the dropwise addition, and continue stirring for 15-20 minutes after the dropwise addition is completed to obtain mixture A;

[0015] S4: Addition of synergist and homogenization: Cool the mixture A to 35-40℃, add the synergist, adjust the speed to 800-900r / min and stir for 10-15 minutes, then cycle and homogenize 2-3 times with a pressure of 20-25MPa and a feed temperature of 35-40℃ to obtain mixture B;

[0016] S5: pH adjustment and finished product packaging: Detect the pH value of mixture B, and finely adjust it to 5.5-6.5 with 10% sodium bicarbonate solution or 0.5mol / L dilute hydrochloric acid. Then filter it through a 0.22μm microporous membrane and fill it in a sterile environment with a temperature of 30-35℃ and a relative humidity of ≤60% to obtain the finished organic water-soluble fertilizer.

[0017] Preferably, the particle size of the diatomaceous earth in step S1 is 10-20 μm; and the particle size of the activated carbon in step S2 is 200-300 mesh.

[0018] Preferably, in step S3, after potassium humate and the composite amino acid are completely dissolved, the viscosity of the solution (40℃) is 3.5-4.0 mPa·s; in step S4, the particle size distribution of the homogenized mixture B needs to satisfy Dv50≤0.08μm and Dv90≤0.2μm.

[0019] Preferably, in step S5, light-proof polyethylene bottles are used for filling, with specifications of 1L / 5L, and the bottles are sealed and labeled after filling.

[0020] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0021] 1. This invention addresses the complex composition of crude wood vinegar by designing a three-stage vacuum distillation process to precisely separate substances with different boiling points. This increases the acetic acid content from 7.46% in the crude liquid to over 12%, and reduces the tar content from 2.01% to below 0.1%. This solves the toxicity problem of direct application of wood vinegar and increases the concentration of effective components. Simultaneously, the small amount of phenolic substances retained during distillation synergistically interacts with chitosan oligosaccharides in the synergist, increasing the fertilizer's efficacy against soil-borne diseases to over 85%, exceeding the expected function of "simple nutrient supply." This solves the technical problem that traditional fertilizers cannot simultaneously control soil-borne diseases.

[0022] 2. This invention first chelates trace elements with compound amino acids, and then adjusts the pH of the system to 5.5-6.5 using sodium bicarbonate, avoiding the precipitation problem of trace elements caused by the strong acidity of wood vinegar. This increases the fertilizer nutrient utilization rate from 50% in traditional mixing methods to over 80%. At the same time, the chelated elements and potassium humate work synergistically to promote the formation of soil aggregates. Tests have shown that soil water retention rate increases by 20%-30% after applying this fertilizer, solving the technical defect of "rapid water and fertilizer loss" in existing water-soluble fertilizers.

[0023] 2. The product of this invention integrates three major functions: "nutrient supply, soil improvement and disease control", overcoming the shortcomings of traditional fertilizers with only one function; and it is compatible with drip irrigation, sprinkler irrigation and other integrated water and fertilizer equipment, which improves application efficiency by 40% and reduces labor costs by 30%, meeting the needs of large-scale agricultural production. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] Based on the above formula and preparation method, three sets of example cases and three sets of comparative cases were set up. The controlled variables were "wood vinegar purification process", "chelation step" and "synergist addition", respectively. The raw material dosage and process parameters for each group are detailed as follows:

[0026] Example 1

[0027] Raw material formula (based on a total mass of 100kg): 40kg purified wood vinegar, 18kg potassium humate, 10kg compound amino acids, 6kg chelated trace elements (EDTA-Ca 2.5kg, EDTA-Mg 1.5kg, EDTA-Zn 1.5kg, boric acid 0.5kg), 2.5kg synergist (chitosan oligosaccharide 1.2kg, brassinolide 0.1kg, deionized water 1.2kg), 0.8kg pH adjuster (food grade sodium bicarbonate), 12.7kg deionized water;

[0028] Preparation process details:

[0029] Wood vinegar pretreatment: Add 1.5% diatomaceous earth to crude wood vinegar, stir at 42℃ and 350r / min for 35 minutes, and filter under 0.4MPa pressure;

[0030] Gradient distillation: First stage: distillation at 0.06 MPa and 62℃ for 1.8 hours; second stage: distillation at 0.08 MPa and 88℃ for 2.2 hours; third stage: distillation at 0.09 MPa and 112℃ for 1 hour; fraction II is adsorbed with 0.8% activated carbon at 25℃ for 2.5 hours.

[0031] Chelation reaction: Add potassium humate and compound amino acids at 52℃ and stir for 22 minutes; add trace elements for chelation at 62℃ and stir for 32 minutes; add purified wood vinegar solution dropwise (6 mL / min); control pH at 5.2-5.3.

[0032] Homogenization and packaging: Add synergist at 38℃ and stir at 850r / min for 12 minutes, homogenize 3 times at 22MPa, fine-tune pH to 5.8, and aseptically fill at 32℃.

[0033] Example 2

[0034] Raw material formula (based on a total mass of 100kg): 45kg purified wood vinegar, 20kg potassium humate, 12kg compound amino acids, 8kg chelated trace elements (3kg EDTA-Ca, 2kg EDTA-Mg, 2kg EDTA-Zn, 1kg boric acid), 3kg synergist (1.5kg chitosan oligosaccharide, 0.2kg brassinolide, 1.3kg deionized water), 1kg pH adjuster (food grade sodium bicarbonate), 11kg deionized water;

[0035] Preparation process details:

[0036] Wood vinegar pretreatment: Add 2% diatomaceous earth to crude wood vinegar, stir at 45℃ and 400r / min for 40 minutes, and filter under 0.5MPa pressure;

[0037] Gradient distillation: First stage: distillation at 0.06 MPa and 65℃ for 2 hours; second stage: distillation at 0.08 MPa and 90℃ for 2.5 hours; third stage: distillation at 0.09 MPa and 115℃ for 1 hour; fraction II is adsorbed with 1% activated carbon at 30℃ for 3 hours.

[0038] Chelation reaction: Add potassium humate and compound amino acids at 55℃ and stir for 25 minutes; add trace elements for chelation at 65℃ and stir for 35 minutes; add purified wood vinegar solution dropwise (at a rate of 8 mL / min); control the pH at 5.3-5.4.

[0039] Homogenization and packaging: Add synergist at 40℃ and stir at 900r / min for 15 minutes, homogenize 3 times at 25MPa, fine-tune pH to 6.0, and aseptically fill at 35℃.

[0040] Example 3

[0041] Raw material formula (based on a total mass of 100kg): 35kg purified wood vinegar, 15kg potassium humate, 8kg compound amino acids, 5kg chelated trace elements (2kg EDTA-Ca, 1kg EDTA-Mg, 1kg EDTA-Zn, 1kg boric acid), 2kg synergist (1kg chitosan oligosaccharide, 0.1kg brassinolide, 0.9kg deionized water), 0.5kg pH adjuster (food grade sodium bicarbonate), 34.5kg deionized water;

[0042] Preparation process details:

[0043] Wood vinegar pretreatment: Add 1% diatomaceous earth to crude wood vinegar, stir at 40℃ and 300r / min for 30 minutes, and filter under 0.3MPa pressure;

[0044] Gradient distillation: First stage: distillation at 0.06 MPa and 60℃ for 1.5 hours; second stage: distillation at 0.08 MPa and 85℃ for 2 hours; third stage: distillation at 0.09 MPa and 110℃ for 1 hour; fraction II is adsorbed with 0.5% activated carbon at 25℃ for 2 hours.

[0045] Chelation reaction: Add potassium humate and compound amino acids at 50℃ and stir for 20 minutes; add trace elements to be chelated at 60℃ and stir for 30 minutes; add purified wood vinegar solution dropwise (at a rate of 5 mL / min); control the pH at 5.0-5.1.

[0046] Homogenization and packaging: Add synergist at 35℃ and stir at 800r / min for 10 minutes, homogenize twice at 20MPa, fine-tune pH to 5.5, and aseptically fill at 30℃.

[0047] Comparative Example 1 (without wood vinegar purification process)

[0048] Raw material formula (based on a total mass of 100kg): 40kg crude wood vinegar (test indicators: acetic acid 7.46%, tar 2.01%, pH 2.84), 18kg potassium humate, 10kg compound amino acids, 6kg chelated trace elements, 2.5kg synergist, 0.8kg pH adjuster, and 12.7kg deionized water;

[0049] Preparation process details: Except for the fact that the wood vinegar is not pretreated and gradient distilled, and the crude wood vinegar is used directly, the other steps (chelation reaction, addition of synergist, homogenization, and packaging) are completely consistent with Example 1.

[0050] Comparative Example 2 (chelation step omitted)

[0051] Raw material formula (based on a total mass of 100kg): 40kg purified wood vinegar, 18kg potassium humate, 10kg compound amino acids, 6kg non-chelated trace elements (2.5kg calcium chloride, 1.5kg magnesium sulfate, 1.5kg zinc sulfate, 0.5kg boric acid), 2.5kg synergist, 0.8kg pH adjuster, and 12.7kg deionized water;

[0052] Preparation process details: Except for not performing the chelation reaction between trace elements and complex amino acids, and directly adding non-chelated trace elements to the potassium humate-amino acid mixture, the other steps (purification of wood vinegar, addition of synergist, homogenization, and packaging) are completely consistent with Example 1.

[0053] Comparative Example 3 (without added synergist)

[0054] Raw material formula (based on a total mass of 100kg): 40kg purified wood vinegar, 18kg potassium humate, 10kg compound amino acids, 6kg chelated trace elements, 0.8kg pH adjuster, and 15.2kg deionized water (to make up for the corresponding mass of synergists).

[0055] Preparation process details: Except for the absence of synergists, the other steps (purification of wood vinegar, chelation reaction, homogenization, and packaging) are completely consistent with those in Example 1.

[0056] II. Performance Testing

[0057] 1. Sample preparation

[0058] Each group prepared 10L of organic water-soluble fertilizer samples, sealed them, and stored them in a light-protected environment at 25℃ for 7 days. During this period, the sample status (whether it separates into layers or precipitates) was observed every day. After 7 days, various performance tests were conducted. Each group of samples was tested in parallel 3 times, and the average value was taken as the final result.

[0059] 2. Test Items, Standards and Methods

[0060] Acetic acid content was determined by high-performance liquid chromatography (HPLC) using an HPLC system equipped with a UV detector. A C18 column (250 mm × 4.6 mm, particle size 5 μm) was selected. The mobile phase was a mixture of methanol and 0.1% phosphoric acid aqueous solution at a volume ratio of 5:95. The flow rate was set at 1.0 mL / min, the detection wavelength at 210 nm, the column temperature at 30 °C, and the injection volume at 10 μL. Before measurement, the sample was filtered through a 0.22 μm microporous membrane to remove impurities before being injected into the chromatograph. The acetic acid content was calculated by comparing the peak area with the standard curve.

[0061] The tar content was determined according to the gravimetric method in GB / T 1341-2007 "Method for Determination of Moisture in Coal Tar", using an electronic analytical balance with an accuracy of 0.1 mg and a vacuum drying oven. 10 g of the test sample was accurately weighed and placed in a pre-weighed evaporating dish. The evaporating dish was then placed in a vacuum drying oven and dried to constant weight at 105℃ and a vacuum of 0.08 MPa. After cooling, the total mass of the evaporating dish and the residue was weighed. The tar content was obtained by calculating the percentage of the residue mass to the sample mass.

[0062] pH value determination shall be performed in accordance with GB / T 17318-1998 "Determination of pH Value of Pesticides", using a precision pH meter with an accuracy of 0.01. First, dilute the test sample 10 times with deionized water, stir thoroughly, then insert the electrode of the pH meter into the diluted solution. After the instrument reading stabilizes, record the pH value at this point, which is the pH value of the sample.

[0063] Nutrient utilization efficiency was determined using a pot experiment method, employing an electronic analytical balance (accuracy 0.1g) and an elemental analyzer. The test crop was tomato (variety "Fen Guan No. 1"), and the soil was acidic red soil (pH 5.0, organic matter content 1.5%). Pots were 25cm in diameter and 30cm in height, each containing 5kg of soil. Fertilization was performed via drip irrigation, with each application being 100mL (the sample needed to be diluted 500 times), once a week. A control group was included (applied only with an equal amount of water). Sixty days after transplanting (harvest date), the dry weight of the plants was measured, and the nitrogen, phosphorus, and potassium contents in the plants were analyzed using an elemental analyzer. Nutrient utilization efficiency was calculated using the formula: "Nutrient utilization efficiency = (Nutrient accumulation in the treatment group - Nutrient accumulation in the control group) / Fertilizer input × 100%".

[0064] The efficacy against soil-borne diseases was determined through field trials using a measuring tape and counting board. The experimental sites were continuously cropped tomato greenhouses (where the annual incidence of bacterial wilt was above 30%). Each experimental group had a plot area of ​​200㎡, with three replicates. Fertilization was performed via drip irrigation. The sample was diluted 500 times and applied as a root drench at transplanting (200mL / plant), and sprayed once during fruit setting (10L / 100㎡). The control group was sprayed with the same amount of water. Thirty days after transplanting, the number of bacterial wilt-infected plants in each plot was investigated, the incidence rate was calculated, and the efficacy against soil-borne diseases was obtained using the formula: "Effectiveness = (Incidence rate in control group - Incidence rate in treatment group) / Incidence rate in control group × 100%".

[0065] Soil water retention rate was determined using the TDR soil moisture meter method. Sandy loam was used as the test soil. The sample was diluted 500 times and sprayed evenly onto the soil surface (10 L / m²). The control group was sprayed with an equal amount of water. The soil moisture content at a depth of 10 cm was measured using the TDR soil moisture meter at 1, 3, 5, 7, and 10 days after fertilization. The soil water retention rate was calculated using the formula: "Soil water retention rate = (Soil moisture content on day 10 / Soil moisture content on day 1) × 100%".

[0066] Stability was determined using a static observation method in a constant temperature and humidity incubator. The test sample was placed in the incubator at 25°C and 60% relative humidity for 30 days. During this period, the sample was observed daily for phenomena such as stratification, precipitation, and discoloration, and the observations were recorded in detail to assess the sample's stability.

[0067] Particle size distribution was determined according to GB / T 19077-2016 "Particle Size Analysis - Laser Diffraction Method" using a laser particle size analyzer. The test sample was diluted 100 times with deionized water, ultrasonically dispersed for 5 minutes, and then injected into the laser particle size analyzer. The instrument automatically detected and recorded the particle size distribution data of the sample, focusing on three indicators: Dv10, Dv50, and Dv90, to evaluate the homogeneity of the system.

[0068] 3. Test Results

[0069]

[0070] III. Results Analysis

[0071] Verification of the necessity of wood vinegar purification process: Comparative Example 1 did not use wood vinegar pretreatment and gradient distillation process, and directly used crude wood vinegar, with a tar content as high as 1.95% (far exceeding the 0.07%-0.09% of the examples), resulting in the fertilizer pH dropping to 3.2 (strongly acidic). After application, the tomato roots showed scorching symptoms, and the nutrient utilization rate was only 45.8% (less than 60% of the examples). At the same time, impurities in the crude wood vinegar caused the sample to separate and change color within 30 days, with a particle size Dv50 of 0.156μm (poor system uniformity). In contrast, after purification, Examples 1-3 had a tar content ≤0.09%, a stable pH of 5.5-6.0, and a nutrient utilization rate of 79.5%-85.1%, with excellent stability, proving that the wood vinegar purification process is the key to solving fertilizer toxicity and improving performance.

[0072] Verification of the importance of the chelation step: Comparative Example 2 omitted the chelation step of trace elements and complex amino acids, and directly used non-chelated elements. Although the purification effect of wood vinegar was good (acetic acid 12.6%, tar 0.08%), the non-chelated elements reacted with the acidic components of wood vinegar and precipitated, resulting in slight precipitation in the sample. The particle size Dv50 increased to 0.098 μm, and the nutrient utilization rate dropped to 58.3% (24 percentage points lower than Example 1). In contrast, Examples 1-3, due to the chelation reaction, had trace elements in the form of stable chelates without precipitation, and the nutrient utilization rate remained high, verifying the core role of the chelation step in improving nutrient utilization and system stability.

[0073] synergistic effect verification of the synergist: Comparative Example 3, without the addition of the synergist, had a bacterial wilt control efficacy of only 45.3% (less than 53% of Example 1). Although the nutrient utilization rate (81.9%) and soil water retention rate (76.5%) were close to those of the Example, it lost its disease control function. However, Examples 1-3, due to the addition of chitosan oligosaccharide and brassinolide, synergized with the phenolic substances retained in the wood vinegar, and the control efficacy was increased to 84.2%-88.3% without affecting other properties. This proves that the synergist is the key to achieving the disease control function of fertilizer and produced a synergistic effect of "1+1>2".

[0074] Summary of advantages of the example: Example 2, due to the use of a higher proportion of purified wood vinegar (45%), potassium humate (20%), and synergist (3%), and the optimization of distillation and homogenization parameters, showed the best performance in terms of acetic acid content (13.5%), nutrient utilization rate (85.1%), bacterial wilt prevention efficacy (88.3%), and soil water retention rate (81.5%). At the same time, it had the smallest particle size Dv50 (0.068μm) and the best stability, making it the most suitable solution for large-scale agricultural production.

[0075] in conclusion

[0076] This invention utilizes an innovative process of "gradient distillation purification of wood vinegar - chelation - pH synergistic regulation - synergist addition" to prepare an organic water-soluble fertilizer that effectively solves the problems of high toxicity of crude wood vinegar, low nutrient utilization rate and single function of traditional fertilizers. At the same time, it realizes the resource utilization of wood vinegar. The process parameters are clear and highly operable, making it suitable for industrial production. Moreover, the product has functions of nutrient supply, soil improvement and disease control, and has significant application value in the fields of facility agriculture and ecological agriculture.

[0077] The above description of the embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An organic water-soluble fertilizer using wood vinegar as a raw material, characterized in that, It is made from the following raw materials in parts by weight: 35-45 parts purified wood vinegar, 15-20 parts potassium humate, 8-12 parts compound amino acids, 5-8 parts chelated trace elements, 2-3 parts synergist, 0.5-1 part pH adjuster, and 11-34.5 parts deionized water. The purified wood vinegar is obtained from crude wood vinegar from a biomass boiler through pretreatment, gradient distillation, and adsorption purification. It contains acetic acid ≥12%, tar content ≤0.1%, pH 3.5-4.0, and density 1.12-1.15 g / cm³. 3 The compound amino acid is composed of glycine, glutamic acid, and proline in a mass ratio of 2:1:1, with a total amino acid content ≥95%; the chelated trace elements include 2-3 parts EDTA-Ca, 1-2 parts EDTA-Mg, 1-2 parts EDTA-Zn, and 0.5-1 parts boric acid, with a chelation degree ≥90%; the synergist is a mixture of 1-1.5 parts chitosan oligosaccharide and 0.1-0.2 parts brassinolide; the pH adjuster is food-grade sodium bicarbonate. The pretreatment involves adding diatomaceous earth to the crude wood vinegar, stirring, and then filtering. The gradient distillation purification involves vacuum distillation of the pretreated wood vinegar, collecting the fractions, and then adsorbing and filtering them with activated carbon to obtain purified wood vinegar.

2. The organic water-soluble fertilizer using wood vinegar as a raw material according to claim 1, characterized in that, The potassium humate is water-soluble, with a humic acid content ≥70% and water-insoluble matter ≤5%; the rotational viscosity (40℃) of the purified wood vinegar is 2.0-2.2 mPa. s, particle size distribution Dv50≤0.07μm.

3. The organic water-soluble fertilizer using wood vinegar as a raw material according to claim 1, characterized in that, The test indicators for the crude wood vinegar from the biomass boiler were as follows: acetic acid 7.46%, formic acid 0.39%, propionic acid 0.19%, tar 2.01%, pH 2.84, and density 1.0653 g / cm³. 3 Particle size distribution: Dv10=0.020μm, Dv50=0.056μm, Dv90=0.200μm.

4. A method for preparing an organic water-soluble fertilizer using wood vinegar as a raw material according to any one of claims 1-3, characterized in that, Includes the following steps: S1: Wood vinegar pretreatment: Take crude wood vinegar from biomass boiler, add diatomaceous earth at 1%-2% of the crude wood vinegar mass, stir for 30-40 minutes at 40-45℃ and 300-400r / min, then filter through a 0.2μm precision plate and frame filter press at 0.3-0.5MPa pressure, and collect the filtrate to obtain pretreated wood vinegar; S2: Gradient distillation purification of wood vinegar: The pretreated wood vinegar is passed into a vacuum distillation column and distilled in three stages. The first stage is distilled for 1.5-2 hours under vacuum of 0.06 MPa, temperature of 60-65℃, and reflux ratio of 1:2, and fraction I is discarded. The second stage is distilled for 2-2.5 hours under vacuum of 0.08 MPa, temperature of 85-90℃, and reflux ratio of 1:1, and fraction II is collected. The third stage is distilled for 1 hour under vacuum of 0.09 MPa, temperature of 110-115℃, and reflux ratio of 1:3, and the residue at the bottom of the column is discarded. 0.5%-1% of activated carbon by mass is added to fraction II, and the mixture is allowed to stand at 25-30℃ for 2-3 hours for adsorption, with stirring at 100 r / min every 30 minutes. The mixture is then filtered through a 0.1 μm microporous membrane to obtain purified wood vinegar. S3: Raw material mixing and chelation reaction: Add deionized water to the reactor, heat to 50-55℃, add potassium humate and compound amino acids sequentially at 500-600 r / min, and stir for 20-25 minutes until completely dissolved; keep the stirring speed constant, add the chelated trace elements and heat to 60-65℃, and stir for 30-35 minutes; then add purified wood vinegar dropwise at a rate of 5-8 mL / min, adjusting the pH of the system to 5.0-5.5 with 10% sodium bicarbonate solution during the dropwise addition, and continue stirring for 15-20 minutes after the dropwise addition is completed to obtain mixture A; S4: Addition of synergist and homogenization: Cool the mixture A to 35-40℃, add the synergist, adjust the speed to 800-900r / min and stir for 10-15 minutes, then cycle and homogenize 2-3 times with a pressure of 20-25MPa and a feed temperature of 35-40℃ to obtain mixture B; S5: pH adjustment and finished product packaging: Detect the pH value of mixture B, and finely adjust it to 5.5-6.5 with 10% sodium bicarbonate solution or 0.5mol / L dilute hydrochloric acid. Then filter it through a 0.22μm microporous membrane and fill it in a sterile environment with a temperature of 30-35℃ and a relative humidity of ≤60% to obtain the finished organic water-soluble fertilizer.

5. The method for preparing an organic water-soluble fertilizer using wood vinegar as a raw material according to claim 4, characterized in that, The particle size of diatomaceous earth in step S1 is 10-20 μm; the particle size of activated carbon in step S2 is 200-300 mesh.

6. The method for preparing an organic water-soluble fertilizer using wood vinegar as a raw material according to claim 4, characterized in that, In step S3, after the potassium humate and the complex amino acids are completely dissolved, the viscosity of the solution (at 40°C) is 3.5-4.0 mPa. s; In step S4, the particle size distribution of the homogenized mixture B must satisfy Dv50≤0.08μm and Dv90≤0.2μm.

7. The method for preparing an organic water-soluble fertilizer using wood vinegar as a raw material according to claim 1, characterized in that, In step S5, light-proof polyethylene bottles are used for filling, with specifications of 1L / 5L. After filling, the bottles are sealed and labeled.

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