Swellable carrier-based functional reactants for reducing methane produced in soil and fertilizer compositions comprising same

Abstract

The present invention relates to a functional reactant based on an expandable carrier for reducing methane generated in soil and a fertilizer composition comprising the same, and more particularly, to a functional reactant based on an expandable carrier, a method for preparing the same, and a fertilizer comprising the same, which are characterized in that: the functional reactant based on an expandable carrier can be used for reducing methane generated in soil; the functional reactant comprises: an expandable carrier; and a functional substance contained in the carrier wherein the expandable carrier is pre-expanded. According to the present invention, the functional reactant based on the expandable carrier and the fertilizer comprising the same have an excellent effect in reducing methane generated in soil, and can increase the temperature of the carrier by a reaction between each component and moisture, thereby improving the expansibility of the carrier and the activation of a catalytically active metal, and improving the activity of the catalyst. Therefore, the methane reduction effect can be maximized, and the settling function and the slow release function of the fertilizer in the soil are enhanced, so that the methane reduction function can be maintained for a long period of time.

Description

TECHNICAL FIELD

[0001] The present application relates to a fertilizer composition, and more particularly, to an expandable carrier-based functional reactant for reducing methane production in soil and a fertilizer composition including the same. BACKGROUND

[0002] Since rice is grown in freshwater in a paddy field, a large amount of methane is produced by decomposition of organic matter during rice cultivation. It is known that about 60% of farmland in Korea is a paddy field, and a large amount of methane produced in a freshwater paddy field has a global warming potential of about 24 times higher than that of carbon dioxide (CO2) per molecule. In the background of the global warming problem becoming more serious and the international community's pressure on reducing greenhouse gas emissions increasing through climate agreements and the like, there is an urgent need to develop measures for reducing methane emissions in paddy fields.

[0003] One of the methods for effectively reducing methane production in a paddy field during rice cultivation is to inhibit the activity of methanogens by effectively reducing the amount of active electrons increased by the reduction of freshwater to a reduced state. The activity of active electrons can be effectively inhibited by the addition of an electron acceptor. In the process of rice cultivation, electron acceptors that can be applied to paddy field soil include Fe 3+ , Mn 4+ , SO4 2- , and NO3 - ions, and the use of a soil conditioner containing a large amount of these electron acceptors can effectively reduce methane production.

[0004] Therefore, a slag siliceous fertilizer is most widely used, which not only improves the growth and yield of rice, but also can reduce methane production. However, the purpose of developing such a slag siliceous fertilizer is to improve the growth and yield of rice, and thus there is an urgent need to develop a new type of fertilizer that can effectively reduce methane production.

[0005] Japanese Laid-Open Patent No. 2005-177646 (published on July 7, 2005) discloses a method of forming an aerobic coating layer having a pH of 8 or more by using a blast furnace water quenched slag to coat a water bottom containing organic matter deposited by a sediment of a bottom mud, thereby preventing the production of methane gas from the water bottom. However, since the blast furnace slag contains trace amounts of inorganic ions that can be electron acceptors (iron content of 1% or less, manganese oxide content of 0.5% or less, and sulfate ion content of 2% or less), it is almost impossible to obtain an effect of reducing methane production when the slag siliceous fertilizer is applied to soil as a main raw material.

[0006] Also, Korean Patent No. 10-0829438 (issued on May 7, 2008) relates to a siliceous fertilizer composition for reducing methane gas generation in soil and a method for reducing methane gas generation in soil using the same, i.e., a siliceous fertilizer composition for reducing methane gas generation in soil and a method for reducing methane gas generation by applying the siliceous fertilizer composition to a crop cultivation soil, the fertilizer composition comprising i) 50 to 95 wt% of blast furnace slag; and ii) 5 to 50 wt% of an electron acceptor component selected from the group consisting of steelmaking slag, gypsum, phosphogypsum, coal ash, and a mixture thereof. The siliceous fertilizer composition of the above invention sufficiently exerts the effect of a siliceous fertilizer by promoting the growth of crops to increase the yield, and at the same time, it is described that the activity of methanogens can be inhibited by reducing the activity of active electrons in soil, thereby effectively reducing methane gas generation. However, it does not teach or suggest a natural swellable carrier and a catalytically active metal coated thereon.

[0007] Also, Korean Patent No. 10-2314179 (issued on October 12, 2021) relates to a fertilizer composition for reducing methane gas generation comprising ethephon as an active ingredient and use thereof, and it is described that the fertilizer composition of the above invention is excellent in the effect of reducing the emission amount of methane gas emitted in a crop cultivation soil without affecting the growth and amount of crops, and can reduce fertilizer application to once, thereby not only saving labor but also preventing environmental pollution. However, it does not teach or suggest a natural swellable carrier and a catalytically active metal coated thereon.

[0008] As described above, there is a problem in the prior art that the methane reduction effect is limited or the economic benefit is low.

[0009] Therefore, there is a need to properly improve the current siliceous fertilizer of blast furnace slag for improving paddy field soil, and thus to develop a method capable of effectively reducing methane gas generation.

[0010] To solve this problem, the present invention has developed a fertilizer having a methane reduction effect by combining a natural swellable carrier with a catalytically active metal. SUMMARY

[0011] Technical problem to be solved by the invention

[0012] To solve the problem of greenhouse gases (e.g., methane) generated in soil according to the present invention, the present invention aims to provide a swellable carrier-based functional reactant for reducing methane comprising a natural swellable carrier and a catalytically active metal, a fertilizer comprising the same, and a method for preparing a swellable carrier-based functional reactant for reducing methane.

[0013] On the other hand, the technical problem of the present application is not limited to the above-mentioned technical problem, and other technical problems not mentioned can be clearly understood by those skilled in the art to which the present application pertains through the following description.

[0014] Means for solving the problem

[0015] To achieve the above object, one aspect of the present application provides a functional reactant based on an expandable carrier, characterized by comprising: an expandable carrier; and a functional substance contained in the carrier, wherein the expandable carrier is pre-expanded.

[0016] A preferred embodiment of one aspect of the present application is characterized in that the expandable carrier is a perlite-based expandable carrier.

[0017] A preferred embodiment of one aspect of the present application is characterized in that the functional substance contained in the carrier is a catalytically active metal for reducing methane or a substance for supplying nutrients to plants.

[0018] A preferred embodiment of one aspect of the present application is characterized in that the catalytically active metal includes copper and iron oxide.

[0019] A preferred embodiment of one aspect of the present application is characterized in that the catalytically active metal includes 5 to 10% by weight of copper and 10 to 15% by weight of iron oxide, based on 100% by weight of the functional reactant based on an expandable carrier, and the total amount of copper and iron oxide is 10 to 20% by weight, based on 100% by weight of the functional reactant based on an expandable carrier.

[0020] A preferred embodiment of one aspect of the present application is characterized in that the specific gravity of the functional reactant based on an expandable carrier is 1 to 3.

[0021] A preferred embodiment of one aspect of the present application is characterized in that the specific gravity of the functional reactant based on an expandable carrier is 1 to 1.2.

[0022] Also, another aspect of the present application provides a fertilizer including: the functional reactant based on an expandable carrier of the present application; and a plant nutrient substance.

[0023] Also, still another aspect of the present application provides a method of preparing the functional reactant based on an expandable carrier of the present application.

[0024] Another embodiment of the aspect of the present application is characterized by comprising: Step 1, a step of heat-treating an expandable carrier at a temperature of 800 to 1000°C to expand to 50 to 70%, thereby obtaining an expanded carrier; and Step 2, a step of coating a functional substance on the outer surface and pores of the obtained expanded carrier.

[0025] Another embodiment of the aspect of the present application is characterized in that the expandable carrier is a perlite-based expandable carrier.

[0026] Another embodiment of the aspect of the present application is characterized in that the functional substance contained in the carrier is a catalytically active metal for reducing methane or a substance for supplying nutrients to plants.

[0027] Effects of the invention

[0028] According to the present application, the functional carrier-based reactant of the present application and the fertilizer containing the same are excellent in reducing methane produced in soil, and the temperature of the carrier can be increased by the reaction between the components and moisture, thereby improving the expandability of the carrier and the activation of the catalytically active metal, thereby the methane reduction effect can be maximized, and the settlement function and the slow-release function of the fertilizer in soil are strengthened, thereby having the advantage of being able to maintain the methane reduction function for a long time. DETAILED DESCRIPTION

[0029] Unless otherwise defined, all technical and scientific terms used in the present specification have the same meaning as commonly understood by one of ordinary skill in the art to which the present application pertains. The nomenclature used in general is in accordance with the methods widely known and generally used in the art.

[0030] Throughout the specification, when a certain part "comprises" a certain constituent element, it means that other constituent elements are not excluded, unless otherwise specified, and can further include other constituent elements.

[0031] Hereinafter, the present application will be described in detail.

[0032] An aspect of the present application provides a functional carrier-based reactant of an expandable carrier containing an expandable carrier and a functional substance.

[0033] Specifically, the functional carrier-based reactant for reducing methane of the present application is characterized by comprising: an expandable carrier; and a functional substance contained in the carrier, wherein the expandable carrier is pre-expanded.

[0034] Hereinafter, each component is described in detail.

[0035] The first component of the functional reactant of the present application comprises an expandable carrier. In particular, the expandable carrier specifically includes a perlite-based expandable carrier. Among them, the expandable carrier is pre-expanded, which means that the expandable carrier is expanded by heat treatment before being contacted with other components, i.e., before being coated with a catalytically active metal or mixed with a fertilizer. Preferably, the expandable carrier used in the present application is used to be pre-expanded to a certain degree, for example, 50% to 70%.

[0036] Perlite is a volcanic glass (volcanic rock) that has a property of expanding to about 4 to 20 times when rapidly heated at high temperature, and through the expansion process, many fine pores are formed inside, thereby having very high porosity. This porous structure is very advantageous to provide a habitat for microorganisms, which are protected when moving within the pores, thereby improving the survival rate, and due to the large surface area of the carrier, catalytic or adsorption reactions are effectively carried out. Also, perlite has the properties of being light in weight, chemically stable and neutral (pH 6.5 to 7.5), thereby being suitable for carrying microorganisms and catalytic substances while minimizing the impact on the soil.

[0037] In this invention, perlite that has been heat-treated at 800°C to 1000°C and expanded to 50% to 70% is used as an expandable support. When using this expandable support, this perlite-based expandable support can function as a catalyst support and has multiple functions, such as maximizing methane reduction performance and improving sustainability by acting as an exothermic reaction medium, adjusting specific gravity to achieve settling properties, slow release, and increased reactivity. Specifically, as described above, because the expanded perlite of this invention has a porous structure, it provides a large surface area for coating catalytically active metals (copper, iron oxide, etc.) on its outer surface and within its pores. This provides stable support for the catalyst, thereby enabling it to function as a catalyst support for effectively carrying out the methane reduction reaction in soil. Furthermore, the perlite support may contain exothermic reactants such as quicklime, which raises the temperature to 80°C to 100°C when reacting with moisture in the soil. This temperature increase further enhances the catalyst activity, thus serving as a medium for more effectively inducing the exothermic reaction of methane reduction. Furthermore, perlite typically has a low specific gravity and tends to float easily in paddy field water. However, by coating it with metals such as iron oxide or copper to adjust its specific gravity, it can sink in the water. This allows the fertilizer composition to be stably positioned in the paddy field water, enabling the methane reduction reaction to continue for an extended period. Moreover, the perlite-based expandable carrier of this invention provides a slow-release function, allowing the exothermic reactants and catalyst to be released gradually in the soil. This allows the exothermic and catalytic reactions to continue for a specified time, thus maintaining the methane reduction effect over a long period. Furthermore, the expanded perlite exhibits increased reactivity due to increased pore size and surface area, thus facilitating the activation of catalytically active metals and the exothermic reaction, which plays a crucial role in maximizing methane reduction performance.

[0038] Furthermore, the second component of the perlite-based expandable carrier of the present invention contains functional substances. These functional substances include catalytically active metals for reducing methane emissions or substances for supplying nutrients to plants.

[0039] Catalytically active metals include iron oxide and copper, which can promote the oxidation of methane or inhibit the activity of methane-producing bacteria. Since the reaction rate increases with increasing temperature, the methane reduction effect can be effectively improved when the temperature of the support increases.

[0040] This catalytically active metal is characterized by being uniformly coated on the outer surface and within the pores of the support. This coating can be achieved by mixing the support with solid catalytically active metal powder, by mixing with a liquid slurry of catalytically active metal, or by immersing the support in a solution of catalytically active metal; the specific method can be readily chosen by those skilled in the art.

[0041] Based on 100% by weight of the functional reactants based on the expandable carrier, the catalytically active metal comprises 5% to 10% by weight of copper and 10% to 15% by weight of iron oxide, and the total amount of copper and iron oxide is preferably 10% to 20% by weight based on 100% by weight of the functional reactants based on the expandable carrier. Within the above range, the methane reduction effect may be reduced, and exceeding the above range has the following disadvantages: the methane reduction effect due to overuse is negligible, uniform coating is difficult, and it is not economically preferable.

[0042] Furthermore, for the substances used to supply nutrients to plants, any substances available in the art for supplying nutrients to all plants can be used, and this can be readily selected by those skilled in the art; the present invention does not impose any specific limitations on this.

[0043] Furthermore, the functional reactants based on expandable carriers of the present invention may also include exothermic reactants that can react with water to generate heat, as well as adhesives.

[0044] In this invention, quicklime is used as an exothermic reactant that generates heat through reaction with water, particularly water in paddy fields, to induce an exothermic reaction. When this exothermic reacts with water in the soil, the temperature rises to 80°C to 100°C through the exothermic reaction. This temperature increase is transferred to the carrier and ultimately increases the reactivity of the catalytically active metal, thereby inducing more effective decomposition of methane or interfering with methane formation. In other words, the exothermic effect of this reactant provides an environment in which the catalytically active metal can function more effectively.

[0045] When this exothermic reactant is used, it is mixed with a carrier (i.e., perlite) and evenly distributed within the carrier.

[0046] Furthermore, in this invention, the binder can be molasses, rosin, or natural oils, which stabilize the carrier particles and facilitate the good aggregation of fertilizer particles. This binder can be mixed with the carrier and then dried to form particles in the form of a coating of perlite and an exothermic reactant. The amounts of the exothermic reactant and binder used in this invention are preferably set to be sufficient to stably position the carrier while maximizing the methane reduction effect in the soil.

[0047] When quicklime is used as an exothermic reactant included in the functional reactants of the present invention, it is preferably added on a basis of 0.1% to 20% by weight of the total reactant composition. If the amount added is less than 0.1% by weight, the increase in carrier temperature is limited due to insufficient exothermic reaction, and the activity of the catalytically active metal may be reduced. Conversely, if it exceeds 20% by weight, the exothermic effect is excessive, which may have a negative impact on biological activity in the soil, and the stability of the carrier may be reduced. Therefore, for optimal methane reduction reaction, it is suitable to use 0.1% to 20% by weight of quicklime. More preferably, it is suitable to use 1% to 10% by weight of quicklime.

[0048] The binder helps stabilize the particles of the carrier, thus ensuring the fertilizer composition remains stably positioned in water, and also increases the fertilizer's cohesiveness. In this invention, it is preferably added at 1% to 5% by weight of the total composition. If the amount used is less than 1% by weight, the cohesiveness is insufficient and the carrier may not be able to settle stably in water; if it exceeds 5% by weight, the viscosity of the composition increases, which may make it difficult to deliver to the soil. Therefore, to ensure the particle binding and cohesiveness of the composition, it is preferable to use 1% to 5% by weight of the binder.

[0049] In this invention, by adjusting the appropriate range of addition amounts of the exothermic reactant and the binder, a composition can be provided that allows the carrier to settle stably in water and maintain its methane-reducing function for an extended period of time.

[0050] The functional reactant based on an expandable carrier of the present invention is characterized in that its specific gravity is 1 to 3, preferably 1 to 1.2.

[0051] Perlite is typically low in density and tends to float easily in water. In this case, its effectiveness in removing methane from water may be reduced, and the effect may be difficult to sustain.

[0052] However, for the functional reactant based on a perlite expandable carrier of the present invention, as described above, by using a coating of iron oxide and copper, the specific gravity is adjusted to 1 to 3, preferably 1 to 1.2, thereby allowing it to sink well in water, resulting in excellent methane removal performance, and this effect can be sustained. If the specific gravity is less than 1, it floats on the water surface and is difficult to contact the methane-producing area, which may reduce the methane reduction effect. Conversely, if the specific gravity exceeds 3, the carrier sinks excessively and is located in the deep soil layer, resulting in the problem of ineffective methane reduction reaction. Therefore, in the present invention, the specific gravity is set to 1 to 3, so that the reactant is in stable contact with the soil to achieve methane reduction performance.

[0053] Furthermore, as described in the following experimental examples, the functional reactants based on expandable carriers of the present invention are highly effective in reducing methane production in soil. By increasing the temperature of the carrier through the reaction between each component and water, the expandability of the carrier and the activation of catalytically active metals can be improved, thereby maximizing the methane reduction effect. In addition, the sedimentation and slow-release functions of fertilizers in the soil are enhanced, thus having the advantage of maintaining the function of reducing methane over a long period of time.

[0054] Furthermore, in another aspect, the present invention provides a fertilizer comprising: the functional reactant of the present invention for reducing methane based on an expandable carrier; and phytonutrient substances.

[0055] Phytonutrients, as substances that can be used in plants, generally refer to components of fertilizers. Preferably, phytonutrients include phosphorus (P), nitrogen (N), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S). As an example, this includes nutrients in a weight ratio of 1:2:2:3:1:1 of phosphorus:nitrogen:potassium:calcium:magnesium:sulfur, but is not limited thereto.

[0056] This phytonutrient can be sprayed and adsorbed onto the outer surface and pores of perlite in solution form within the functional reactant based on an expandable carrier for methane reduction of the present invention.

[0057] This fertilizer is applied to the soil, preferably to paddy field water, so as to not only continuously supply nutrients to plants, but also reduce the methane produced in the soil.

[0058] Furthermore, in another aspect, the present invention provides a method for preparing the functional reactants based on expandable carriers.

[0059] Specifically, the method for preparing functional reactants based on expandable carriers according to the present invention includes: step 1, heat-treating the expandable carrier at a temperature of 800°C to 1000°C to expand it to 50% to 70% to obtain an expanded carrier; and step 2, coating the outer surface and pores of the obtained expanded carrier with a functional substance.

[0060] In step 1, a perlite-based expandable carrier is used as an expandable carrier, and the perlite-based expandable carrier is heat-treated at a temperature of 800°C to 1000°C to expand to 50% to 70%, thereby obtaining an expanded perlite carrier.

[0061] This heat treatment expands the pores of perlite, thereby increasing its specific surface area and facilitating the adsorption of catalytically active metals in the subsequent step 2.

[0062] Step 2 involves coating the outer surface and pores of the obtained expanded perlite carrier with a functional material.

[0063] Coating can be performed by mixing a carrier with a functional material powder in a solid state, or by mixing a functional material in a liquid slurry state, or by immersing a carrier in a functional material in a solution state, and the specific method can be readily selected by those skilled in the art.

[0064] Functional substances include catalytically active metals for reducing methane or substances for supplying nutrients to plants. The catalytically active metals for reducing methane may include iron oxide and copper, and the substances for supplying nutrients to plants may be any substances known in the art and can be readily selected by those skilled in the art.

[0065] Based on 100% by weight of the functional reactant based on the expandable carrier, the catalytically active metal comprises 5% to 10% by weight of copper and 10% to 15% by weight of iron oxide, and is mixed, dispersed or impregnated such that the total amount of copper and iron oxide is 10% to 20% by weight based on 100% by weight of the functional reactant based on the expandable carrier. The mixing, dispersion or impregnation conditions can be appropriately selected by those skilled in the art as long as the above conditions are met.

[0066] For coated perlite, moisture can be removed through a drying process to stabilize the active metal coating.

[0067] In step 2, optionally, when coating the catalytically active metal, the perlite carrier can be mixed with a binder consisting of molasses, rosin, or natural oils and dried.

[0068] The adhesive serves to attach the exothermic reactants to the expandable carrier, stabilize the carrier particles, and allow the fertilizer particles to aggregate well.

[0069] The mixing process can be carried out using a mixer that rotates at an appropriate speed, and the speed and mixer can be easily selected by those skilled in the art, and no specific limitations are imposed on them in this invention.

[0070] Next, through a drying process, particles can be formed that combine coated perlite with exothermic reactants that can generate heat.

[0071] Furthermore, after step 2, the exothermic reactant can be uniformly distributed inside the carrier by mixing the coated perlite carrier with an exothermic reactant that can react with water to generate heat.

[0072] Exothermic reactants that can generate heat include quicklime.

[0073] This mixing process can be carried out using a mixer that rotates at an appropriate speed, and the speed and mixer can be easily selected by those skilled in the art, and no specific limitations are imposed on them in this invention.

[0074] The final product prepared in this manner, namely the functional reactant based on the expandable carrier, is characterized by a specific gravity of 1 to 3, preferably 1 to 1.2. For the functional reactant based on the perlite expandable carrier, by using a coating of iron oxide and copper to adjust the specific gravity to 1 to 3, preferably 1 to 1.2, it sinks well in water, thereby exhibiting excellent methane removal performance, and this effect can be sustained.

[0075] The following examples and experimental cases illustrate specific aspects of the present invention. It should be noted that these are merely representative examples related to the present invention and should not be construed as limiting the scope of the invention.

[0076] <Example> Preparation of the functional reactant based on an expandable carrier for reducing methane according to the present invention

[0077] Perlite is heat-treated at a temperature of 800°C to 1000°C to expand it by 50% to 70% to obtain expanded perlite.

[0078] Iron oxide and copper were coated on the outer surface and inside the pores of expanded perlite, with compositions as shown in Table 1 below. At this time, the specific gravities of Examples 1, 2, and 3 were 1.1, 1.2, and 1.0, respectively, while the specific gravities of Comparative Examples 1, 2, and the control group were 0.9, 0.8, and 0.5, respectively.

[0079] Then, using a mixer, the coated perlite carrier and quicklime are mixed to ensure that they are evenly distributed inside the carrier.

[0080] Finally, the coated perlite carrier is mixed with molasses, rosin, or natural oils and dried to form particles in the form of coated perlite and exothermic reactants.

[0081] [Table 1]

[0082] Iron oxide (wt%) Copper (wt%) Pearlite (wt%) Example 1 15 5 80 Example 2 10 10 80 Example 3 12 8 80 Comparative Example 1 5 3 92 Comparative Example 2 6 2 92 Control group 0 0 100

[0083] Examples 1 to 3 are compositions with a specific gravity of 1 to 1.2 (Example 1: 1.1, Example 2: 1.2, Example 3: 1.0), which are intended to sink well in water and achieve a high methane reduction effect.

[0084] Comparative Examples 1 and 2 are compositions with a specific gravity of less than 1 (Comparative Example 1: 0.9, Comparative Example 2: 0.8), which float on the water surface and have a lower methane reduction effect.

[0085] The control group is used as a baseline (specific gravity 0.5) when there are no applicable comparison components.

[0086] <Experimental Example> Analysis of the physical properties of the reactants of the present invention and fertilizers containing them

[0087] Sedimentation and position stability experiment

[0088] 1. Determination of settling properties

[0089] The composition prepared in the above embodiment was placed in a water tank and the sinking time and whether the composition sank into the water were measured. If the composition sank stably into the water, it was recorded as "sinking property: yes"; if it floated on the surface of the water, it was recorded as "sinking property: no".

[0090] 2. Evaluation of positional stability

[0091] The composition was observed to remain stably stationary at a specific position in the water for a specified time. If it exhibited positional stability, it was recorded as "stable"; if it floated or moved, it was recorded as "unstable".

[0092] Measurement of methane reduction effect

[0093] ①Preparation of soil samples

[0094] To maintain identical conditions, six samples were prepared using the same paddy field soil (see Table 1 above). Equal amounts of organic matter (rice straw) and anaerobic microbial culture solution were added to each sample to create an environment conducive to methane production.

[0095] ② The suitability of the fertilizer composition and the establishment of the control group

[0096] The samples were divided into two groups. One group was treated with the fertilizer composition, and the other group was set as a control group without fertilizer.

[0097] A specified amount (10g) of fertilizer composition was added to each sample, while no fertilizer was added to the control group.

[0098] ③ Maintain sealed and anaerobic conditions

[0099] The samples are placed in a sealed container to suppress oxygen supply and create anaerobic conditions. Once sealed, all samples maintain the same temperature and humidity, thus providing a uniform experimental environment.

[0100] ④ Monitoring of methane concentration

[0101] Gas chromatography (GC) was used to determine the methane concentration in each sample every 24 hours, with the experimental period set to 7 days.

[0102] The amount of methane produced in the control group samples and each fertilizer composition sample was recorded periodically and compared.

[0103] ⑤ Data analysis and calculation of methane reduction rate

[0104] After the experiment, the methane reduction rate was calculated based on the cumulative methane production of each sample. By comparing the cumulative methane production of the control group with the cumulative methane production of each composition sample, the methane reduction rate was calculated using the following mathematical formula 1.

[0105] [Mathematical Expression 1]

[0106]

[0107] Experimental results

[0108] The results of the above experiments are shown in Table 2 below.

[0109] [Table 2]

[0110]

[0111] The composition of Example 1 (composed of 15% iron oxide, 5% copper, and 80% perlite) had a specific gravity of 1.1, sank stably in water, and exhibited stable positional stability after settling, with a methane reduction rate of 78%. The composition of Example 2 (composed of 10% iron oxide, 10% copper, and 80% perlite) had a specific gravity of 1.2, sank stably in water, exhibited stable positional stability after settling, and showed the highest methane reduction rate of 82%. The composition of Example 3 (composed of 12% iron oxide, 8% copper, and 80% perlite) had a specific gravity of 1.0, sank stably in water, exhibited stable positional stability after settling, and showed a good methane reduction rate of 80%.

[0112] Conversely, for the compositions of Comparative Example 1 and Comparative Example 2, due to the low coating ratio of iron oxide and copper, the specific gravity was less than 1, so they floated on the water surface and exhibited lower methane reduction rates of 35% and 30%, respectively.

[0113] The control group was in a condition without fertilizer composition, and had no methane reduction effect, with cumulative methane production reaching 100 ppm.

[0114] Conclusion and analysis

[0115] The compositions of Examples 1 to 3 have a specific gravity of 1 to 1.2, sink stably in water, and exhibit high methane reduction effects. In particular, the composition of Example 2 showed the highest methane reduction rate of 82%. Conversely, the compositions of Comparative Examples 1 and 2, as well as the composition of the control group, floated on the water surface, with relatively low methane reduction effects.

[0116] By adjusting the ratio of iron oxide to copper coating in this experimental example, the fertilizer composition with adjusted specific gravity stably sinks in paddy field water. After settling, its positional stability remains stable, and it can maintain the methane reduction effect for a long time. It can be seen that by including the reactants of the present invention in the fertilizer, a stable and excellent methane reduction effect is achieved in soil, specifically in paddy field water.

Claims

1. A functional reactant based on an expandable carrier, characterized in that, include: Expandable carrier, and The carrier contains functional substances; The expandable carrier is pre-expanded.

2. The functional reactant based on an expandable carrier according to claim 1, characterized in that, The expandable carrier is an expandable carrier based on perlite.

3. The functional reactant based on an expandable carrier according to claim 1, characterized in that, The functional substances contained in the carrier are catalytically active metals used to reduce methane or substances used to supply nutrients to plants.

4. The functional reactant based on an expandable carrier according to claim 3, characterized in that, The catalytically active metals used to reduce methane include copper and iron oxide.

5. The functional reactant based on an expandable carrier according to claim 2, characterized in that, Based on 100 wt% of functional reactants on an expandable support, the catalytically active metals include 5 wt% to 10 wt% copper and 10 wt% to 15 wt% iron oxide. Furthermore, based on 100% by weight of functional reactants based on expandable carriers, the total amount of copper and iron oxide is 10% to 20% by weight.

6. The functional reactant based on an expandable carrier according to claim 1, characterized in that, The specific gravity of functional reactants based on expandable carriers is 1 to 3.

7. The functional reactant based on an expandable carrier according to claim 1, characterized in that, The specific gravity of the functional reactants based on the expandable carrier is 1 to 1.

2.

8. A fertilizer, characterized in that, include: Functional reactants based on expandable carriers for reducing methane, as described in claim 1; And phytonutrients.

9. A method for preparing a functional reactant based on an expandable carrier according to claim 1, characterized in that, include: Step 1 involves heat-treating the expandable carrier at a temperature of 800°C to 1000°C to expand it to 50% to 70%, thereby obtaining the expanded carrier. as well as Step 2 is the step of coating the outer surface and pores of the obtained expanded carrier with a functional substance.

10. The method for preparing functional reactants based on expandable carriers according to claim 9, characterized in that, The expandable carrier is an expandable carrier based on perlite.

11. The method for preparing functional reactants based on expandable carriers according to claim 9, characterized in that, The functional substances contained in the carrier are catalytically active metals used to reduce methane or substances used to supply nutrients to plants.

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