A functional reactant based on an expandable carrier for reducing methane generated in soil, and a fertilizer composition containing the same.

Abstract

The present invention provides a functional reactant based on an expandable carrier for reducing methane generated in soil, a fertilizer composition containing the same, and a method for producing the functional reactant. [Solution] A functional reaction substance based on an expandable carrier, comprising an expandable carrier and a functional substance contained in the carrier, wherein the expandable carrier is pre-expanded. [Effects] The functional reactant based on the expandable carrier of the present invention, and the fertilizer containing it, have an excellent effect in reducing methane generated in the soil. By raising the temperature of the carrier through the reaction of its components with water, the expandability of the carrier and the activation of the catalytically active metal are improved, maximizing the methane reduction effect. Furthermore, the settling and slow-release functions of the fertilizer are added to the soil, providing the advantage of maintaining the methane reduction function over a long period of time.

Description

Technical Field

[0001] The present invention relates to a fertilizer composition, specifically a reactant for reducing methane generated in soil, and a fertilizer composition containing the same.

Background Art

[0002] In paddy fields, rice is cultivated in a fresh water state. Therefore, during the cultivation process of rice, organic matter decomposes and a considerable amount of methane is generated. In the case of Korea, about 60% of agricultural land is paddy fields. Methane generated in fresh water paddy fields is known to have a global warming potential about 24 times higher per molecule than carbon dioxide (CO2). As the global warming problem becomes serious and international pressure to reduce greenhouse gas emissions increases through climate agreements and the like, it is necessary to establish countermeasures to reduce methane generation in paddy fields.

[0003] In the process of cultivating rice, one way to effectively reduce methane generation in paddy fields is to reduce the amount of active electrons that increase due to the development of a reducing state by fresh water and suppress the activity of methanogens. The activity of active electrons can be suppressed by adding an electron acceptor. In the process of cultivating rice, electron acceptors applicable to paddy soil include Fe 3+ , Mn 4+ , SO4 2- , NO3 - ions, etc. By using a soil conditioner containing a large amount of such electron acceptors, methane generation can be reduced.

[0004] In addition to promoting the growth and quantity of rice, slag silicate fertilizers are widely used to reduce methane generation. However, such slag silicate fertilizers have been developed aiming at promoting the growth and quantity of rice, and there is a need to develop a new fertilizer that can effectively reduce methane generation.

[0005] Patent Document 1 (published July 7, 2005) discloses a method for preventing methane gas generation at the bottom of a body of water where organic matter-containing sediment has accumulated, by covering the bottom with granulated blast furnace slag to form an aerobic covering layer in which the pH of the interstitial water is 8 or higher. However, blast furnace slag contains trace amounts of inorganic ions that can act as electron acceptors (1% iron, 0.5% manganese oxide, less than 2% sulfate ions), and when used in soil as the main raw material for slag siliceous fertilizer, little effect in reducing methane generation can be expected.

[0006] Furthermore, Patent Document 2 (registered 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. The siliceous fertilizer composition comprises i) 50-95% by weight of blast furnace slag and ii) 5-50% by weight of an electron acceptor component selected from the group consisting of steelmaking slag, gypsum, gypsum phosphate, coal ash, and mixtures thereof, and a method for reducing methane gas generation by applying the siliceous fertilizer composition to crop cultivation soil. The invention states that the siliceous fertilizer composition of the invention fully exhibits the effect of a siliceous fertilizer that promotes the growth and increases the quantity of crops, and can efficiently reduce methane gas generation by reducing the activity of active electrons in the soil and suppressing the activity of methane-producing bacteria. However, this does not suggest or imply natural expandable carriers and catalytically active metals coated thereon.

[0007] Furthermore, Patent Document 3 (registered October 12, 2021) relates to a fertilizer composition for reducing methane gas generation containing etephon as an active ingredient and its use, stating that the fertilizer composition of the present invention does not affect crop growth and yield, and is excellent in reducing the amount of methane gas emitted from the soil of agricultural crop cultivation, allowing for a reduction in fertilizer application to once, thereby not only reducing labor but also preventing environmental pollution. However, this does not suggest or imply the use of a natural expanding carrier and a catalytically active metal coated thereon.

[0008] As mentioned earlier, conventional technologies have problems such as limited effectiveness in reducing methane emissions or low economic efficiency.

[0009] Therefore, it is necessary to develop a method to appropriately improve the slag siliceous fertilizer currently supplied nationally for soil improvement in rice paddies, thereby efficiently reducing methane gas emissions.

[0010] To address this issue, the present invention has developed a fertilizer that reduces methane emissions by combining a natural expanding carrier with a catalytically active metal. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] Japanese Patent Publication No. 2005-177646 [Patent Document 2] Republic of Korea Registered Patent No. 10-0829438 [Patent Document 3] Republic of Korea Registered Patent No. 10-2314179 Gazette [Overview of the Initiative] [Problems that the invention aims to solve]

[0012] The present invention has been made to solve the problem of greenhouse gases such as methane generated in soil, and provides a functional reactant based on an expandable carrier for methane reduction, comprising a natural expandable carrier and a catalytically active metal, a fertilizer containing the same, and a method for producing a functional reactant based on an expandable carrier for methane reduction.

[0013] On the other hand, the technical problems that this invention aims to solve are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those with ordinary skill in the art to which this invention belongs from the description below. [Means for solving the problem]

[0014] To achieve the above object, one aspect of the present invention provides a functional reactive substance based on an expandable carrier, which comprises an expandable carrier and a functional substance contained in the carrier, and the expandable carrier is pre-expanded.

[0015] The expandable carrier is an expandable carrier based on perlite.

[0016] The functional substance contained in the carrier is a catalytic active metal for methane reduction or a substance for supplying nutrients to plants.

[0017] The catalytic active metal includes copper and iron oxide.

[0018] The catalytic active metal contains 5 to 10% by weight of copper and 10 to 15% by weight of iron oxide based on 100% by weight of the functional reactive substance based on the expandable carrier, and the combined amount of copper and iron oxide is 10 to 20% by weight based on 100% by weight of the functional reactive substance based on the expandable carrier.

[0019] The specific gravity of the functional reactive substance based on the expandable carrier is 1 to 3. <000008l>

[0020] The specific gravity of the functional reactive substance based on the expandable carrier is 1 to 1.2.

[0021] Another aspect of the present invention provides a fertilizer comprising the functional reactive substance based on the expandable carrier according to claim 1 of the present invention and a group of plant nutrients.

[0022] Furthermore, another aspect of the present invention provides a method for manufacturing the functional reactive substance based on the expandable carrier of the present invention.

[0023] Furthermore, another aspect of the present invention is characterized by including a step of heat-treating the expandable carrier so as to expand it to 50 to 70% at a temperature of 800 to 1,000 °C to obtain an expanded carrier (step 1), and a step of coating the outer surface and pores of the obtained expanded carrier with a functional substance (step _{2}).

[0024] The expandable carrier is an expandable carrier based on perlite.

[0025] The functional substance contained in the carrier is a catalytic active metal for methane reduction or a substance for supplying nutrients to plants.

Advantages of the Invention

[0026] According to the present invention, the functional reaction substance based on the expandable carrier of the present invention and the fertilizer containing the same have an excellent effect of reducing methane generated in the soil. By increasing the temperature of the carrier through the reaction of the constituent components and moisture, the expandability of the carrier and the activation of the catalytic active metal are improved, and the effect of methane reduction can be maximized. In addition, the sedimentation and slow-release functions of the fertilizer are added to the soil, and there is an advantage that the function of methane reduction can be maintained for a long time.

Modes for Carrying Out the Invention

[0027] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs. In general, the terms used in this specification are well known and commonly used in the relevant technical field.

[0028] Throughout the specification of the present application, when a part states that a certain component "includes", this means that it includes other components as well, rather than excluding other components, unless otherwise stated to the contrary.

[0029] Hereinafter, the present invention will be described in detail. One aspect of the present invention provides a functional reaction substance based on an expandable carrier containing an expandable carrier and a functional substance.

[0030] Specifically, the functional reaction substance based on the carrier for methane reduction of the present invention includes an expandable carrier and a functional substance contained in the carrier, and the expandable carrier is characterized in that it is pre-expanded.

[0031] Let's explain each component. The first component of the functional reactant of the present invention includes an expandable carrier. In particular, the expandable carrier specifically includes an expandable carrier based on perlite. Here, the expandable carrier is pre-expanded, meaning that the expandable carrier is heat-treated to expand before being mixed with other components, namely, a catalytically activated metal coating or fertilizer. Preferably, the expandable carrier used in the present invention is pre-expanded to some extent, for example, 50-70%.

[0032] Perlite is a volcanic glass (volcanic rock) that expands to approximately 4 to 20 times its original size when rapidly heated to high temperatures. This expansion process creates numerous fine pores within the material, resulting in extremely high porosity. This porous structure is highly advantageous for providing a habitat for microorganisms, allowing them to function in a protected environment within the pores, thus increasing their survival rate. Furthermore, the large surface area of ​​the carrier facilitates efficient catalytic and adsorption reactions. In addition, perlite is lightweight, chemically stable, and neutral (pH 6.5-7.5), minimizing its impact on soil and making it suitable for supporting microorganisms and catalytic substances.

[0033] In this invention, perlite is an expandable carrier that has been heat-treated at 800-1,000°C to expand to 50-70%. When this is used, such a perlite-based expandable carrier performs various functions that maximize the performance of methane reduction and enhance its sustainability, such as acting as a catalyst support, an exothermic reaction mediator, settling properties through specific gravity adjustment, slow-acting properties, and increased reactivity. Specifically, as mentioned above, the expanded perlite of this invention has a porous structure, providing a large surface area for coating the outer surface and pores with catalytically active metals (copper, iron oxide, etc.). This allows the catalyst to be stably supported, and it plays the role of a catalyst support that enables the methane reduction reaction to proceed efficiently in the soil. Furthermore, the perlite carrier contains exothermic reactants such as quicklime, which, when reacting with moisture in the soil, raise the temperature to 80-100°C. This temperature increase further enhances the activity of the catalyst, thereby acting as an exothermic reaction mediator that efficiently induces the methane reduction reaction. Furthermore, while perlite generally has a low specific gravity and is prone to floating in paddy field water, its specific gravity can be adjusted by coating it with metals such as iron oxide or copper, causing it to sink. This ensures that the fertilizer composition remains stable in the paddy field, allowing the methane reduction reaction to continue for an extended period. Additionally, the perlite-based expandable carrier of the present invention provides a slow-release function that gradually releases exothermic reactants and catalysts in the soil. This allows the exothermic and catalytic reactions to continue for a certain period, maintaining the methane reduction effect for a long time. Moreover, in an expanded state, perlite has increased pores and surface area, leading to higher reactivity. This allows for more efficient activation of catalytic active metals and exothermic reactions, playing a crucial role in maximizing methane reduction performance.

[0034] Furthermore, the second component of the perlite-based expandable carrier of the present invention includes a functional substance. The functional substance includes a catalytically active metal for methane reduction, or a substance for supplying nutrients to plants.

[0035] The catalytically active metals include iron oxide and copper. Such catalysts either promote the oxidation of methane or suppress the activity of methanogenic bacteria. As the temperature increases, the reaction rate accelerates. Therefore, when the temperature of the support rises, the methane reduction effect due to the increased reaction rate can be efficiently enhanced.

[0036] Such catalytically active metals are characterized by being uniformly coated on the outer surface and pores of the carrier. Such coating can be performed by mixing the carrier with a solid catalytically active metal powder, by mixing with a liquid slurry of catalytically active metals, or by immersing the carrier in a solution of catalytically active metals. The specific method can be easily selected by those skilled in the art.

[0037] The catalytically active metal contains 5-10% by weight of copper and 10-15% by weight of iron oxide, based on 100% by weight of the functional reactant based on the expandable carrier. Preferably, the combined amount of copper and iron oxide is 10-20% by weight, based on 100% by weight of the functional reactant based on the expandable carrier. If the amount is below the above range, the methane reduction effect deteriorates, and if it exceeds the above range, the increase in the methane reduction effect due to excessive use is slight, uniform coating is difficult, and it is economically undesirable.

[0038] Furthermore, the substances used to supply nutrients to plants can be any substances used to supply nutrients to plants in the field, and these can be easily selected by those skilled in the art; the present invention does not specifically limit them.

[0039] Furthermore, the functional reactant based on the expandable carrier of the present invention may further include an exothermic reactant that can react with water to generate heat, and a binder.

[0040] Exothermic reactants that generate heat when reacting with water are substances that induce an exothermic reaction when reacting with moisture in the soil, particularly water in rice paddies, and in this invention, quicklime is used. When such exothermic reactants react with moisture in the soil, the temperature rises to 80-100°C due to the exothermic reaction. This temperature rise is transferred to the carrier, ultimately increasing the reactivity of the catalytically active metal, which leads to more efficient decomposition of methane or inhibits methane production. In other words, the exothermic effect of such reactants provides an environment in which the catalytically active metal acts efficiently.

[0041] These exothermic reactants are mixed with the carrier, i.e., perlite, and distributed evenly within the carrier.

[0042] Furthermore, in this invention, the binder used is molasses, resin, or natural oil, which plays a role in stabilizing the carrier particles and cohesive the fertilizer particles well. After mixing with the carrier, such a binder forms particles in which dried and coated perlite and exothermic reactants are bound together. It is desirable to set the amount of exothermic reactants and binder used in this invention within an appropriate range to maximize the effect of methane reduction in the soil and to ensure that the carrier is stably positioned.

[0043] When quicklime is used as the exothermic reactant in the functional reactant of the present invention, it is desirable to add it in an amount of 0.1 to 20% by weight of the total reactant composition. If added at less than 0.1% by weight, the exothermic reaction is insufficient, the temperature rise of the support is limited, and the activity of the catalytic active metal decreases. On the other hand, if it exceeds 20% by weight, the exothermic effect becomes excessive, negatively affecting biological activity in the soil and degrading the stability of the support. Therefore, it is desirable to use 0.1 to 20% by weight of quicklime for the optimal methane reduction reaction. More preferably, 1 to 10% by weight of quicklime is used.

[0044] The binder plays a role in helping the carrier particles bind stably, ensuring the fertilizer composition remains stable in water and enhancing the cohesiveness of the fertilizer. In this invention, it is desirable to add 1 to 5% by weight of the binder to the overall composition. If the amount is less than 1% by weight, the cohesive force will be insufficient, and the carrier will not be able to settle stably in water. If it exceeds 5% by weight, the viscosity of the composition will increase, making it difficult to supply to the soil. Therefore, it is desirable to use 1 to 5% by weight of binder to ensure particle binding and cohesiveness of the composition.

[0045] In this invention, by adjusting the appropriate range of addition amounts of exothermic reactants and binders, a composition is provided in which the carrier settles stably in water and maintains its methane reduction function over the long term.

[0046] The functional reactant based on the expandable carrier of the present invention has a specific gravity of 1 to 3, preferably 1 to 1.2.

[0047] Generally, perlite has a low specific gravity and is easily suspended in water. However, in such cases, its methane removal effect in water deteriorates, and this effect is not easily sustained.

[0048] However, as mentioned above, the functional reactant based on the perlite expandable carrier of the present invention sinks well in water by adjusting its specific gravity to 1 to 3, preferably 1 to 1.2, through coating with iron oxide and copper, thereby providing excellent methane removal effects and sustaining such effects. If the specific gravity is less than 1, it floats in water and does not easily come into contact with the methane generation zone, resulting in a deterioration of the methane reduction effect. On the other hand, if the specific gravity exceeds 3, the carrier sinks excessively and is located in the deeper layers of the soil, leading to the problem of ineffective methane reduction reactions not occurring. Therefore, in the present invention, the specific gravity is set to 1 to 3 so that the reactant can stably come into contact with the soil and exhibit methane reduction performance.

[0049] Furthermore, as described in the experimental examples below, the functional reactant based on the expandable carrier of the present invention is excellent at reducing methane generated in the soil. By increasing the temperature of the carrier through the reaction of its constituent components with water, the expandability of the carrier and the activation of the catalytically active metal can be improved, maximizing the methane reduction effect. In addition, the settling and slow-release functions of the fertilizer are added to the soil, allowing the methane reduction function to be maintained for a long period of time.

[0050] Another embodiment of the present invention provides a fertilizer comprising a functional reactant based on an expandable carrier for methane reduction and a group of plant nutrients.

[0051] Plant nutrients are a group of plant nutrients that can be used by plants, and generally refer to the components of fertilizer. Plant nutrients preferably include the nutrients phosphorus (P), nitrogen (N), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S), and as an example, include nutrients in a weight ratio of 1:2:2:3:1:1, but are not limited to this.

[0052] These plant nutrients, in solution form, are sprayed onto the outer surface and pores of perlite in the functional reactant based on the expandable carrier for methane reduction of the present invention, and are adsorbed.

[0053] Such fertilizers are applied to the soil where plants grow, and preferably to the water in the paddy fields, not only to provide a sustained supply of nutrients to the plants but also to reduce methane production in the soil.

[0054] Furthermore, yet another embodiment of the present invention provides a method for producing a functional reactant based on the expandable carrier of the present invention.

[0055] Specifically, the method for producing a functional reactant based on the expandable carrier of the present invention includes the steps of: heat-treating the expandable carrier at a temperature of 800 to 1,000°C to expand it by 50 to 70% to obtain an expanded carrier (Step 1); and coating the outer surface and pores of the obtained expanded carrier with a functional substance (Step 2).

[0056] Step 1 involves using a perlite-based expandable support as the expandable support, and heat-treating the perlite-based expandable support at a temperature of 800-1,000°C to expand it by 50-70% to obtain an expanded perlite support.

[0057] This heat treatment expands the pores of the perlite, thereby increasing the non-surface area of ​​the perlite and facilitating the subsequent adsorption of catalytically active metals in step 2.

[0058] Step 2 involves coating the outer surface and pores of the resulting expanded perlite support with a functional substance.

[0059] Coating can be performed by mixing a carrier with a functional material powder in solid form, by mixing a functional material in liquid slurry form, or by immersing the carrier in a functional material solution. The specific method can be easily selected by those skilled in the art.

[0060] Functional substances include catalytically active metals for methane reduction or substances for supplying nutrients to plants. Here, catalytically active metals for methane reduction include iron oxide and copper, and substances for supplying nutrients to plants can be any substance known in the art, which can be easily selected by those skilled in the art.

[0061] The catalytically active metal contains 5-10% by weight copper and 10-15% by weight iron oxide, based on 100% by weight of the functional reactant based on the expandable carrier, and the combined amount of copper and iron oxide is 10-20% by weight based on 100% by weight of the functional reactant based on the expandable carrier, where the conditions for mixing, dispersion, or immersion can be appropriately selected by those skilled in the art, as long as the above conditions are met.

[0062] The coated perlite undergoes a drying process to remove moisture and stabilize the activated metal coating layer.

[0063] In step 2, the perlite support is selectively mixed with a binder consisting of molasses, resin, or natural oils and dried before coating with the catalytically active metal.

[0064] The binder plays a role in adhering the exothermic reactants to the expandable carrier, stabilizing the carrier particles, and ensuring that the fertilizer particles aggregate well.

[0065] The mixing process is carried out using a mixer rotating at an appropriate speed, and the speed and mixer can be easily selected by those skilled in the art, and the present invention does not specifically limit them.

[0066] Subsequently, the drying process forms particles in which the coated perlite and the exothermic reactant that generates heat are combined.

[0067] Additionally, after step 2, the coated perlite carrier is mixed with an exothermic reactant that reacts with water to generate heat, thereby ensuring even distribution of the exothermic reactant within the carrier.

[0068] The exothermic reaction products that generate heat include quicklime.

[0069] Such a mixing process is 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 the present invention does not specifically limit them.

[0070] The functional reactant based on the expandable support, which is the final product manufactured in this manner, is characterized by having a specific gravity of 1 to 3, preferably 1 to 1.2. The functional reactant based on the perlite expandable support has the advantage of sinking well in water by adjusting its specific gravity to 1 to 3, preferably 1 to 1.2, through coating with iron oxide and copper, thereby providing excellent methane removal and the ability to sustain this effect.

[0071] The process in the present invention will be described in detail below with reference to examples and experimental cases. These are representative examples of the present invention and should not be used to limit the scope of application of the present invention.

[0072] <Examples> Production of functional reactants based on expandable carriers for methane reduction according to the present invention

[0073] Perlite was heat-treated at a temperature of 800-1,000°C until it expanded by 50-70%, thereby obtaining expanded perlite.

[0074] The expanded perlite was coated with iron oxide and copper on its outer surface and within its pores, with the composition ratios shown in Table 1 below. 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.

[0075] Subsequently, a mixer was used to mix the coated perlite carrier with quicklime to ensure even distribution within the carrier.

[0076] Finally, the coated perlite carrier was mixed with molasses, resin, or natural oils and fats, and dried to form particles in which the coated perlite and exothermic reactants were bonded together.

[0077] [Table 1]

[0078] Examples 1 to 3 are compositions whose specific gravity is set to 1 to 1.2 (Example 1: 1.1, Example 2: 1.2, Example 3: 1.0), which sink well in water, and are formulated to achieve a high methane reduction effect.

[0079] Comparative Examples 1 and 2 were set to have a specific gravity of less than 1 (Comparative Example 1: 0.9, Comparative Example 2: 0.8), floated in water, and were compositions with low methane reduction effect.

[0080] The control group is under conditions where the comparative composition is not applied and is used as a reference when measuring methane production (specific gravity 0.5).

[0081] <Example of experiment> Physical property analysis of the reactant of the present invention and fertilizer containing the same Sedimentation and positional stability experiments

[0082] 1. Measurement of sedimentation The compositions produced in the above examples were placed in a tank of water, and the sinking status and time were measured. If the composition sank steadily in the water, it was recorded as "Sinking property: Yes," and if it floated in the water, it was recorded as "Sinking property: No."

[0083] 2. Evaluation of positional stability We observed whether compositions submerged in water remained stable in a specific position in the water for a certain period of time. Here, positional stability was recorded as "stable," and floating or moving was recorded as "unstable."

[0084] Measurement of methane reduction effect (1) Preparation of soil samples To maintain consistent conditions, six samples (see Table 1 above) were prepared using the same paddy field soil. The same amount of organic matter (rice straw) and anaerobic microbial culture solution were added to each sample to create an environment in which methane could be produced.

[0085] (2) Application of fertilizer composition and setting of control group The samples were divided into two groups. One group was treated with the fertilizer composition, while the other group served as a control group without fertilizer.

[0086] A fixed amount (10g) of the fertilizer composition was added to each sample, while no fertilizer was added to the control group.

[0087] (3) Maintaining sealed and anaerobic conditions The samples were placed in sealed containers to prevent oxygen supply, creating anaerobic conditions. After sealing, all samples were maintained at the same temperature and humidity to provide a uniform experimental environment.

[0088] (4) Methane concentration monitoring Using gas chromatography (GC), the methane concentration generated in each sample was measured at 24-hour intervals, and the experimental period was set to 7 days.

[0089] The amount of methane produced in the control group sample and each fertilizer composition sample was recorded periodically and compared and analyzed.

[0090] (5) Data analysis and calculation of methane reduction rate After the experiment, the methane reduction rate was calculated based on the cumulative methane production of each sample. The methane reduction rate was determined by comparing the cumulative methane production of the control group with that of each composition sample, using Equation 1 below.

[0091]

number

[0092] Experimental results The results of the above experiment are shown in Table 2 below.

[0093] [Table 2]

[0094] The composition of Example 1 (consisting of 15% iron oxide, 5% copper, and 80% perlite) has a specific gravity of 1.1, sinks stably in water, exhibits stable positional stability after settling, and shows a methane reduction rate of 78%. The composition of Example 2 (consisting of 10% iron oxide, 10% copper, and 80% perlite) had a specific gravity of 1.2, which allowed it to sink stably, exhibited stable positional stability after settling, and showed the highest methane reduction rate of 82%. The composition of Example 3 (consisting 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 sedimentation, and showed a good methane reduction rate of 80%.

[0095] On the other hand, the compositions of Comparative Example 1 and Comparative Example 2 had a low ratio of iron oxide and copper coating, resulting in a specific gravity of less than 1, which caused them to float, and their methane reduction rates were also low, at 35% and 30%, respectively.

[0096] The control group, under conditions without the fertilizer composition, showed no effect in reducing methane, and the cumulative methane production reached 100 ppm.

[0097] Conclusion and Analysis The compositions of Examples 1-3 had a specific gravity of 1-1.2, sank stably in water, and exhibited a high methane reduction effect. In particular, the composition of Example 2 had the highest methane reduction rate at 82%. In contrast, the compositions of Comparative Examples 1 and 2 and the control group floated in water and exhibited a relatively low methane reduction effect.

[0098] These experimental examples show that fertilizer compositions with adjusted ratios of iron oxide and copper coating to achieve the correct specific gravity sink stably in paddy field water, exhibit stable positional stability after settling, and maintain a long-term methane reduction effect. The reactive substance of the present invention, when incorporated into fertilizer, is stable in soil, specifically in paddy field water, and is excellent at reducing methane.

Claims

1. Expandable carrier, The functional substance contained in the carrier, The aforementioned expandable carrier is characterized by being pre-expanded, and is a functional reaction substance based on an expandable carrier.

2. The functional reaction substance based on the expandable carrier according to claim 1, characterized in that the expandable carrier is a perlite-based expandable carrier.

3. The functional reactant based on the expandable carrier according to claim 1, characterized in that the functional substance contained in the carrier is a catalytically active metal for methane reduction, or a substance for supplying nutrients to plants.

4. The functional reactant based on an expandable carrier according to claim 3, characterized in that the catalytically active metal for methane reduction includes copper and iron oxide.

5. The catalyst-active metal comprises 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 the expandable carrier. The functional reactant based on an expandable carrier according to claim 2, characterized in that the combined 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.

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

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

2.

8. A functional reactant based on an expandable carrier for methane reduction according to claim 1, A fertilizer characterized by containing a group of plant nutrients.

9. A method for producing a functional reactant based on the expandable carrier of claim 1, Step 1 involves heat-treating an expandable carrier at a temperature of 800 to 1,000°C to expand it by 50 to 70%, thereby obtaining an expanded carrier. A method characterized by comprising the step (step 2) of coating the outer surface and pores of the expanded carrier obtained above with a functional substance.

10. The method according to 9, characterized in that the expandable carrier is a perlite-based expandable carrier.

11. The method according to 9, characterized in that the functional substance contained in the carrier is a catalytically active metal for methane reduction, or a substance for supplying nutrients to plants.

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