Fertilizer composition and method for producing the same

Abstract

This disclosure provides a method for producing a fertilizer composition and a fertilizer composition produced by this method. The method for producing the fertilizer composition of this disclosure includes the steps of obtaining a polymer by crosslinking cellulose and a crosslinking agent, and adding the polymer to an aqueous solution of plant fertilizer, mixing, drying, and then obtaining the fertilizer composition. The fertilizer composition of this disclosure has high water absorption capacity and contains nutrients for plant cotton. When the fertilizer of this disclosure is mixed with soil, under drought conditions, water-soluble nutrients are released simultaneously with water, supplying moisture and nutrients to plants, such as cotton, and improving the yield and quality of cotton.

Description

Technical Field

[0001] The present disclosure belongs to the field of agricultural cultivation, and specifically relates to a fertilizer composition and a method for manufacturing the same.

Background Art

[0002] Cotton is one of the natural fibers with the highest demand in the fiber industry, and cotton production has become part of our daily lives. However, the waste in cotton cultivation, processing, and production has an adverse impact on the environment. Cotton requires a large amount of water and nutrients to grow during the cultivation process. According to the article published in "Cotton Incorporated", the water requirement of cotton varies by season, reaching the highest in the middle of the season, about 0.28 inches per day. A total of 157 gallons of water is required to cultivate the cotton used to produce one T-shirt.

[0003] Nutrients are an important source for plants to achieve the maximum yield of cotton, and insufficient nutrients may lead to a decrease in cotton yield. The three main nutrients required for cultivation are nitrogen (N), phosphorus (P), and potassium (K). These constitute three fertilizers called NPK, which are important fertilizers used in cotton production. Other essential nutrients include copper, boron, calcium, magnesium, iron, zinc, cobalt, and molybdenum.

[0004] The development of a fertilizer that can simultaneously supply the water and nutrients required for cotton growth is expected to improve the yield and quality of cotton.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present disclosure provides a method for manufacturing a fertilizer composition and a fertilizer manufactured by the method.

Means for Solving the Problems

[0006] One aspect of the present disclosure provides a method for producing a fertilizer composition, comprising the steps of: obtaining a polymer by crosslinking cellulose and a crosslinking agent; and obtaining the fertilizer composition by adding the polymer to an aqueous solution of plant fertilizer, mixing, and drying it.

[0007] In some embodiments of the present disclosure, the cellulose is recovered from textile waste, and the recovery step includes the steps of: dispersing textile waste containing cotton in an aqueous solution of an organic acid catalyst to obtain a mixed system, wherein the content of the organic acid catalyst in the aqueous solution is 0.1% to 30% by mass; and heating the mixed system to 110 to 180°C and reacting it for 0.5 to 3 hours under a self-generated pressure of 0.1 to 10 MPa to obtain the cellulose.

[0008] In some embodiments of the present disclosure, the organic acid catalyst is one or more selected from the group consisting of methanesulfonic acid, oxalic acid, tartaric acid, citric acid, malic acid, formic acid, and acetic acid.

[0009] In some embodiments of the present disclosure, the step of crosslinking cellulose with a crosslinking agent includes dissolving cellulose powder, alkali metal hydroxide, and urea in water, then adding the crosslinking agent to form a crosslinked aqueous solution, and reacting the crosslinked aqueous solution at 40-50°C for 2-3 hours. Here, the concentration of the crosslinking agent in the crosslinked aqueous solution is 3% to 30% by volume, and the concentration of cellulose in the crosslinked aqueous solution is 0.1% to 5% by mass.

[0010] In some embodiments of the present disclosure, the crosslinking agent is epichlorohydrin, ethylene glycol diglycidyl ether, or a combination thereof.

[0011] In some embodiments of this disclosure, the concentrations of sodium hydroxide and urea in the crosslinked aqueous solution are 1 to 10% by mass and 0.1 to 10% by mass, respectively.

[0012] In some embodiments of this disclosure, the plant fertilizer accounts for 5% to 25% by mass of the fertilizer composition.

[0013] In some embodiments of the present disclosure, the plant fertilizer is a water-soluble fertilizer.

[0014] In some embodiments of the present disclosure, the fertilizer comprises 20% to 40% total nitrogen, 10% to 20% water-soluble phosphorus, and 10% to 20% water-soluble potassium, or the fertilizer is one or more selected from the group consisting of zinc sulfate, ferrous sulfate, and magnesium sulfate.

[0015] In some embodiments of the present disclosure, the manufacturing method further includes the step of grinding the fertilizer composition into particles with a particle size of 100 μm to 700 μm.

[0016] Another aspect of this disclosure provides a fertilizer composition produced by the manufacturing method described above.

[0017] The fertilizer composition of this disclosure has high water absorption capacity and contains plant cotton nutrients. When the fertilizer of this disclosure is mixed with soil, under drought conditions, water-soluble nutrients are released simultaneously with water, supplying moisture and nutrients to plants (e.g., cotton), and improving cotton yield and quality. Furthermore, since the cellulose in the fertilizer composition of this disclosure is derived from cellulose obtained by decomposing textile waste, it is environmentally friendly, decomposes in the soil, and does not pollute the environment.

[0018] The other features and advantages of this disclosure described above will become even clearer by describing exemplary embodiments in detail with reference to the drawings. [Brief explanation of the drawing]

[0019] [Figure 1] This is a flowchart illustrating the preparation of a fertilizer composition according to the present disclosure using recovered cellulose, according to one embodiment of the present disclosure. [Figure 2] This is a schematic diagram illustrating the fertilizer composition of this disclosure. [Figure 3]Photographs of the polymer (SAP) prepared in Example 1, a fertilizer composition containing a commercially available fertilizer (NPK - SAP), and the polymer after fertilizer release. [Figure 4] FTIR analysis diagram of the polymer (SAP) prepared in Example 1, a fertilizer composition containing a commercially available fertilizer (NPK - SAP), and the polymer after fertilizer release. [Figure 5] Content of nutrients in the fertilizer composition prepared in Example 2 by ICP - OES / ICP - MS analysis.

Modes for Carrying Out the Invention

[0020] Hereinafter, the technical solution of the present invention will be further described based on specific examples. The protection scope of the present invention is not limited to the following examples. These examples are for illustrative purposes only and do not limit the present invention in any way.

[0021] The scope of the present disclosure is not limited to the specific examples described herein. The following examples are for illustrative purposes only.

[0022] The manufacturing method of the fertilizer composition of the present disclosure includes a step of obtaining a polymer by subjecting cellulose and a cross - linking agent to a cross - linking reaction, and a step of adding the polymer to an aqueous solution of a plant fertilizer, mixing, and drying to obtain a fertilizer composition.

[0023] In some embodiments, the cellulose may be recovered from textile waste. When the cellulose is recovered from textile waste, a schematic diagram of an embodiment of the manufacturing method of the fertilizer composition of the present disclosure is shown in FIG. 1. The step of recovering cellulose from textile waste includes a step of dispersing textile waste containing cotton in an aqueous solution system of an organic acid catalyst to obtain a mixed system, where the content of the organic acid catalyst in the aqueous solution system is 0.1% to 30% by mass, and a step of heating the mixed system to 110 - 180°C and reacting for 0.5 - 3 hours under a self - generated pressure of 0.1 - 10 MPa to obtain cellulose.

[0024] Textile waste containing cotton may be natural, semi-synthetic and / or synthetic cellulose, or natural cellulose materials. Semi-synthetic cellulose materials include rayon, cupra, polysilicate, lyocell, cellulose acetate, etc. Textile waste containing cotton can obtain cellulose powder after hydrothermal treatment with an organic acid catalyst. The temperature, pressure and reaction time in the hydrothermal treatment process can be selected according to the types and contents of each component in the waste. For example, the temperature can be 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, etc., the corresponding autogenous pressure can be 0.1MPa, 1MPa, 3MPa, 5MPa, 7MPa, 9MPa, 10MPa, etc., and the corresponding reaction time can be 0.5 hours, 1 hour, 2 hours, 3 hours, etc., but not limited to these.

[0025] The organic acid catalyst used in the hydrothermal treatment may be any suitable organic acid catalyst. For example, one or more selected from the group consisting of methanesulfonic acid, oxalic acid, tartaric acid, citric acid, malic acid, formic acid, acetic acid, etc., but not limited to these.

[0026] In some embodiments, the cross-linking reaction step of cellulose and a cross-linking agent includes dissolving cellulose powder, an alkali metal hydroxide, and urea in water, then adding a cross-linking agent to form a cross-linked aqueous solution, and reacting the cross-linked aqueous solution at 40-50°C for 2-3 hours. Here, the concentration of the cross-linking agent in the cross-linked aqueous solution is 3 vol% - 30 vol%, and the concentration of cellulose in the cross-linked aqueous solution is 0.1 mass% - 5 mass%.

[0027] The crosslinking agent may be epichlorohydrin, ethylene glycol diglycidyl ether, or a combination thereof. The crosslinking agent crosslinks with cellulose to form a polymer having a network structure. Since each D-glucose unit of cellulose contains three hydroxyl groups, the polymer can absorb a large amount of liquid relative to its own mass, but it does not dissolve in water. When water is added to the polymer, water enters the polymer network due to osmosis. Crosslinking between molecular chains prevents the polymer from dissolving in water, but forms a swollen gel. This gel can retain moisture even when external pressure is applied.

[0028] In some embodiments of this disclosure, the concentrations of sodium hydroxide and urea in the crosslinked aqueous solution are 1 to 10% by mass and 0.1 to 10% by mass, respectively. Those skilled in the art can select the mass percentage concentrations of sodium hydroxide and urea in the crosslinked aqueous solution according to their actual needs. For example, the concentrations of sodium hydroxide may be 1%, 3%, 5%, 7%, 9%, 10%, etc., and the concentrations of urea may be 0.1%, 1%, 3%, 5%, 7%, 9%, 10%, etc., but are not limited to these.

[0029] In some embodiments of this disclosure, a step of washing the formed polymer after crosslinking may be further included. Washing removes by-products generated in the crosslinking reaction. A specific washing process may involve cutting the solidified mixture into small cubes and washing them, as the mixture solidifies after the crosslinking reaction is complete. The small cubes are immersed in water, and the water is changed every 2-3 hours until the conductivity of the water stabilizes at around 200-300 (μS / cm).

[0030] The cross-linked polymer can be cut before washing to allow subsequent washing and fertilizer adsorption to proceed smoothly. Of course, it is possible to achieve the objectives of the present invention without performing the cutting step.

[0031] Finally, the resulting polymer is mixed with an aqueous solution of plant fertilizer. Because the polymer has high water absorption properties, both the plant fertilizer and water are adsorbed onto the polymer during this process. After drying to remove the water, the plant fertilizer is retained within the polymer, forming a fertilizer composition.

[0032] In some embodiments, the plant fertilizer may be a water-soluble fertilizer. The fertilizer may be a commercially available fertilizer containing 20% ​​to 40% total nitrogen, 10% to 20% water-soluble phosphorus, and 10% to 20% water-soluble potassium. Alternatively, it may be one or more selected from the group consisting of zinc sulfate, ferrous sulfate, and magnesium sulfate.

[0033] In some embodiments, the process further includes crushing the fertilizer composition to obtain particles with a particle size of 100 μm to 700 μm.

[0034] Figure 2 shows a schematic diagram of the formation and use process of the fertilizer composition of this disclosure. In Figure 2, epichlorohydrin is used as an example crosslinking agent, but of course, any other suitable crosslinking agent may be used to form the polymer. As can be seen from the figure, the fertilizer composition of this disclosure is first obtained by compounding plant fertilizer with a polymer using the method described above. When used, it first absorbs water to form a complex rich in water and fertilizer, and after applying this complex to the soil, in the case of drought, water-soluble nutrients are released simultaneously with water, supplying water and nutrients to plants. [Examples]

[0035] Example 1: Synthesis of a fertilizer composition using a commercially available fertilizer 1750 g of sodium hydroxide, 750 g of urea, 1250 g of regenerated cellulose powder, and 1650 ml of deionized water were added to a 40 L reactor. The mixture was stirred for 1 hour and cooled to -15°C. All the cellulose was dissolved in the aqueous solution at -15°C. When the aqueous solution reached room temperature, epichlorohydrin, the crosslinking agent, was added and the mixture was stirred for 30 minutes. The mixture was poured into a stainless steel tray and placed in a 40°C oven to carry out the crosslinking reaction.

[0036] Once the reaction was complete, the mixture solidified, so it was cut into small cubes and washed with water until the conductivity of the water was maintained below 300 μS / cm. The washed polymer was dried at 90°C for 4 hours.

[0037] A water bath containing the target nutrient was prepared by adding 1 g of commercially available fertilizer to 1000 mL of water and mixing thoroughly. The commercially available fertilizer contained 30.0% total nitrogen, 10.1% water-soluble phosphorus, and 10.1% potassium. The dried polymer was placed in the water bath containing the target nutrient (mass ratio of polymer to target nutrient water bath was approximately 1:100) for 1 hour. During this process, the nutrients were absorbed by the polymer. The polymer containing the nutrients was dried at 90°C until completely dry, and then pulverized using a centrifugal mill to a particle size of 100 μm to 600 μm.

[0038] Figure 3 shows photographs of the polymer (SAP) before formation of the fertilizer composition prepared in this embodiment, the formed fertilizer composition (NPK-SAP), and the polymer after fertilizer release. From the photographs, it can be seen that the formed fertilizer composition (NPK-SAP) has changed in volume and color compared to the polymer (SAP) before fertilizer absorption, demonstrating that fertilizer can be supported in a polymer formed by crosslinking of cellulose by the method of this disclosure. From Figure 3, it can be seen that the volume of the fertilizer composition (NPK-SAP) decreases and its color becomes lighter after fertilizer release. This indicates that fertilizer is released from the fertilizer composition obtained by the method of this disclosure and can supply nutrients to plants.

[0039] The FSC and CRC of SAP containing nutrients were measured according to the test methods of ISO (17190-5:2001) and EDANA (ERT 441.2-02). The results of the FSC and CRC measurements indicate that the water absorption capacity of SAP did not decrease significantly even after the addition of nutrients.

[0040] The nutrient concentrations were measured using ICP-OES / ICP-MS in accordance with the EN16711-1-2015 test method. The ICP-OES / ICP-MS measurement results indicate that the nutrient concentrations in SAP are considerably high.

[0041] Example 2: Synthesis of a fertilizer composition using magnesium sulfate, zinc sulfate, and ferrous sulfate as fertilizers 1750 g of sodium hydroxide, 750 g of urea, 1250 g of regenerated cellulose powder, and 1650 ml of deionized water were added to a 40 L reactor. The mixture was stirred for 1 hour and cooled to -15°C. All the cellulose was dissolved in the aqueous solution at -15°C. When the aqueous solution reached room temperature, epichlorohydrin, a crosslinking agent, was added and the mixture was stirred for 30 minutes. The mixture was poured into a stainless steel tray and placed in a 40°C oven for further reaction.

[0042] Once the reaction was complete, the mixture solidified, so it was cut into small cubes and washed with water until the conductivity of the water was maintained below 300 μS / cm. The washed polymer was dried at 90°C for 4 hours.

[0043] A water bath for the target nutrient was prepared by adding 21.38 g of zinc sulfate, 14.64 g of ferrous sulfate, and 20 g of magnesium sulfate to 2 L of deionized water. 400 g of dried polymer was placed in the water bath for the target nutrient, allowing the polymer to absorb the water containing the nutrients. The polymer containing the nutrients was dried at 90°C until completely dry, and then pulverized using a centrifugal mill to obtain a particle size of 100 μm to 700 μm.

[0044] The FSC and CRC of SAP containing nutrients were measured according to the test methods of ISO (17190-5:2001) and EDANA (ERT 441.2-02). The results of the FSC and CRC measurements indicate that the water absorption capacity of SAP did not decrease significantly even after the addition of nutrients.

[0045] The nutrient concentrations were measured using ICP-OES / ICP-MS in accordance with the EN16711-1-2015 test method, and the measurement results are shown in Figure 5. The ICP-OES / ICP-MS measurement results indicate that the nutrient concentrations in SAP are considerably high.

[0046] The above description of the embodiments is intended to facilitate the understanding and application of the invention by those skilled in the art. It will be apparent to those familiar with the art that various modifications can be easily made to these embodiments, and that the general principles described herein can be applied to other embodiments without creative work. Therefore, the invention is not limited to the embodiments herein, and any improvements and modifications made by those skilled in the art based on this disclosure that do not depart from the scope of the invention should be included within the scope of protection of the invention.

Claims

1. A method for producing a fertilizer composition, A process of obtaining a polymer by crosslinking cellulose and a crosslinking agent, A method for producing a fertilizer composition, comprising the steps of adding the polymer to an aqueous solution of plant fertilizer, mixing and drying it, and then obtaining the fertilizer composition.

2. The aforementioned cellulose was recovered from textile waste. The recovery process is as follows: A step of dispersing textile waste containing cotton in an aqueous solution of an organic acid catalyst to obtain a mixed system, wherein the content of the organic acid catalyst in the aqueous solution is 0.1% to 30% by mass, The manufacturing method according to claim 1, comprising the steps of raising the temperature of the mixed system to 110 to 180°C, reacting it for 0.5 to 3 hours under a self-generated pressure of 0.1 to 10 MPa, and then obtaining the cellulose.

3. The production method according to claim 2, wherein the organic acid catalyst is one or more selected from the group consisting of methanesulfonic acid, oxalic acid, tartaric acid, citric acid, malic acid, formic acid, and acetic acid.

4. The step of crosslinking the aforementioned cellulose with the crosslinking agent is: The process includes dissolving cellulose powder, alkali metal hydroxide, and urea in water, then adding the crosslinking agent to form a crosslinked aqueous solution, and reacting the crosslinked aqueous solution at 40-50°C for 2-3 hours. The manufacturing method according to any one of claims 1 to 3, wherein the crosslinking agent has a concentration of 3% to 30% by volume in the crosslinking aqueous solution, and the cellulose has a concentration of 0.1% to 5% by mass in the crosslinking aqueous solution.

5. The manufacturing method according to claim 4, wherein the crosslinking agent is epichlorohydrin, ethylene glycol diglycidyl ether, or a combination thereof.

6. The manufacturing method according to claim 4, wherein the concentrations of sodium hydroxide and urea in the crosslinked aqueous solution are 1 to 10% by mass and 0.1 to 10% by mass, respectively.

7. The manufacturing method according to any one of claims 1 to 6, wherein the plant fertilizer accounts for 5% to 25% by mass of the fertilizer composition.

8. The manufacturing method according to any one of claims 1 to 7, wherein the plant fertilizer is a water-soluble fertilizer.

9. The manufacturing method according to claim 8, wherein the fertilizer contains 20% to 40% total nitrogen, 10% to 20% water-soluble phosphorus, and 10% to 20% water-soluble potassium, or the fertilizer is one or more selected from the group consisting of zinc sulfate, ferrous sulfate, and magnesium sulfate.

10. The manufacturing method according to any one of claims 1 to 9, further comprising the step of crushing the fertilizer composition to obtain particles with a particle size of 100 μm to 700 μm.

11. A fertilizer composition manufactured by the manufacturing method described in any one of claims 1 to 10.

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