KR20240084319A - Method for granulation of bio-sulfur and granular bio-sulfur prepared thereby - Google Patents

Abstract

The present invention relates to a method for granulating biosulfur and granular biosulfur produced thereby, and more specifically, to the steps of mixing liquid biosulfur with an inorganic adhesive to form a dough; Injecting dough; It relates to a method of granulating biosulfur, including the step of drying, and the granular biosulfur produced thereby.
According to the method for manufacturing biosulfur granules of the present invention, the granulation manufacturing period can be shortened compared to the conventional manufacturing method, the freeze-drying cost can be saved, and furthermore, the loss of raw materials during the process can be reduced, and water It can control the stability and provide slow-release sulfur fertilizer.

Description

Method for granulating bio-sulfur and granular bio-sulfur prepared thereby}

The present invention relates to a method for granulating biosulfur and granular biosulfur produced thereby, and more specifically, to the steps of mixing liquid biosulfur with an inorganic adhesive to form a dough; Injecting dough; It relates to a method of granulating biosulfur, including the step of drying, and the granular biosulfur produced thereby. The granular biosulfur of the present invention can be used as a fertilizer.

Sulfur (S) is a component of sulfur-containing amino acids and vitamins and is involved in maintaining protein structure, lipid synthesis, and energy transfer reactions. Sulfur is one of the essential nutritional elements for plants and generally contains 0.1 to 0.5 wt% of dried plants. In particular, onions and garlic, which are crops of the lily family, have a high content of cysteine sulfoxides, which make up aroma components, so more than 1% of sulfur accumulates in the plants. It is known to happen. Therefore, adequate supply of sulfur through fertilizer use is necessary during the crop growth period.

There are no separate standards for sulfur fertilizers in Korea's fertilizer process standards, and farmers generally use sulfur-containing fertilizers with sulfur as the main ingredient, such as ammonium sulfate (yuan), potassium sulfate, and kaolin sulfate. However, currently, sulfur is mainly produced as a by-product during the petroleum refining process, and it is known that the production of sulfuric acid emits sulfur dioxide (SO ₂ ), a pollutant. Therefore, the need for an eco-friendly sulfur extraction process has emerged.

The THIOPAQ® method, a hydrogen sulfide pretreatment method in landfills, is a biological desulfurization method using microorganisms that ionizes H ₂ S into HS ^- and then uses bacteria to produce elemental sulfur, that is, biosulfur.

Bio-sulfur of the present invention is sulfur produced through the biological metabolism of microorganisms. By introducing a microbial process into the process of removing hydrogen sulfide during the purification process of mixed gas such as bio gas and by-product gas generated in metropolitan landfills, etc. produced. Bio-sulfur produced through microbial metabolism has the advantage of being safe from harmful substances such as heavy metals, having excellent hydrophilicity, and having a lower particle size and density than inorganic sulfur (petrochemical sulfur). Additionally, biosulfur is produced in liquid form and is slightly alkaline (pH 8.5), so it has the advantage of being able to be used without additional processing. In contrast, in the case of inorganic sulfur, a liquefaction process is required, and when liquefied, it is strongly alkaline (pH 12 to 14), so there is a limitation in that an additional process is required.

Bio-sulfur can not only be used as an organic farming material for pest management, but also can replace existing chemical fertilizers, so it is evaluated as having very high potential and can play a role in replacing existing sulfur commercialized through chemical processing. It is expected that For example, its application as organic farming material is expected to spread.

Compared to petrochemical sulfur produced by existing chemical methods, biosulfur has small particles of 2~10㎛, slightly alkaline pH around 8, and excellent hydrophilicity toward water, so it can be used in cosmetics, medicine, disinfectants, fertilizers, etc. possible.

Recent research using biosulfur includes improving concrete performance and developing soil purification materials. Agricultural applications include growth and quality control for peppers, suppression of cucumber anthracnose, and pest control such as suppression of citrus borer disease. It is being utilized.

However, in order to use liquid biosulfur, a production form of biosulfur, as a crop growth aid, the problems of the liquid formulation must be considered: large volume, strong odor, possibility of loss due to wind and rainfall, and low dispersibility when diluted in water.

As such, conventional sulfur fertilizers are mainly sprayed in a liquid state, causing problems such as soil acidification, increased loss, and adverse effects on workers. Accordingly, the need to develop granules for composting liquid biosulfur has emerged, and research on methods for producing granular biosulfur has been conducted.

In order to supplement the problems of liquid biosulfur, research on powderization using freeze-drying was conducted, but it was found that the ratio of constituent elements changes during freeze-drying and the concentration of particles is uneven. Therefore, a method is required to synthesize biosulfur at an even concentration without causing changes in its composition.

Among them, granulation can maintain a constant size of the material, increase mechanical strength, and provide porosity to the adsorption material. In Korea, there is a case of developing zeolite aggregate soil using an inorganic binder, and it has been reported to have various pore sizes and to have complete efficacy and sustainability for potassium (K) and phosphorus (P), which are essential elements for crop growth.

Clay minerals are mainly used as inorganic adhesives used to produce granular biosulfur. Clay minerals are generally a general term for ultra-fine hydroxyaluminosilicate minerals with a layered structure and are the main constituent minerals of mudstone, claystone, and soil. am. In clay minerals, various types of mineral groups are created as tetrahedral and octahedral layers alternate in various ratios. Clay minerals have a very large surface area due to their small particle size and interlayering, and the surface is often electrically charged.　The layered structure and surface charge of clay minerals play a role in regulating the natural ecological environment. Water and positive ions can enter and exit between the layered structures, and various organic and inorganic components can be absorbed.　

Clay minerals are composed of alternating layers of [SiO ₄ ] tetrahedral layers and [Al(O,OH) ₆ ] octahedral layers, and the ratio of tetrahedral and octahedral bonds, the type of cation that exists between unit structures, and the presence or absence of water molecules are determined. The mineral species is determined depending on the etc. Depending on the way the tetrahedral layer and octahedral layer are combined, it is classified as 1:1 or 2:1 clay mineral. 1:1 clay minerals are each composed of one tetrahedral layer and one octahedral layer, and include kaolinite and serpentine. 2:1 clay minerals have layers combined in a tetrahedral-octahedral-tetrahedral structure, and include montmorillonite, bentonite, talc, and illite.

In the conventional granular biosulfur production process, the freeze-drying method has problems of long drying time and excessive drying costs, and there is a problem of 10 to 20% loss of raw materials during the process when using granulation equipment. There is a need to provide eco-friendly fertilizers that can be used in organic agriculture by saving time and cost in the process of granulating existing liquid biosulfur and developing granular biosulfur that reduces raw material loss during the process.

In addition, when using biosulfur as a fertilizer, liquid biosulfur fertilizer had the problem of volatilization when sprayed and having a short remaining time in the soil. To solve these problems, research has been conducted to develop granular biosulfur.

Republic of Korea Patent No. 10-1259061 relates to granular sulfur fertilizer and its manufacturing method, which includes granular sulfur fertilizer composed of sulfur, calcite, sericite, red clay, bentonite or zeolite, and kneading, forming and drying steps. A method for manufacturing granular sulfur fertilizer is disclosed.

Republic of Korea Patent No. 10-1996152 relates to a sulfur granular hydrate composition with excellent disintegration and dispersion stability in water and a method for manufacturing the same. It provides a granular hydrate composition with excellent stability in aqueous solution by adding bentonite, and extrusion as a granulation method. A molding method is disclosed.

Republic of Korea Patent No. 10-1584321 relates to a fertilizer containing sulfur and a manufacturing method thereof. It is a granulation method of fertilizer containing sulfur, a process of manufacturing spherical granules through rotation using a molding machine, and rapid granulation. A method is disclosed that does not require high-temperature molding to ensure easy release.

As such, the conventional method for producing granular biosulfur has not been developed to control the dissolution rate of sulfur by adjusting the ratio of inorganic adhesive and to use it as a slow-release fertilizer.

Accordingly, the present inventors have made diligent efforts to develop eco-friendly granular biosulfur that can replace existing liquid biosulfur. As a result, in the case of producing granular biosulfur of the present invention, unlike conventional biosulfur, the elution period of sulfur is controlled. Thus, it was confirmed that a slow-release sulfur fertilizer could be provided, and the present invention was completed.

The purpose of the present invention is to provide a method for granulating biosulfur that can control stability in water and provide a slow-release sulfur fertilizer, and to provide granular biosulfur thereby.

In addition, the purpose of the present invention is to provide a method for granulating biosulfur that has the effect of shortening the manufacturing period, saving freeze-drying costs, and reducing raw material loss compared to existing biosulfur granulation methods.

This invention

As a bio granulation method,

1) Mixing liquid biosulfur with an inorganic adhesive to make dough;

2) Injecting the dough; and

3) It includes the step of drying the injection molded product,

The inorganic adhesive provides a method for granulating biosulfur, which can be used as a fertilizer.

In addition, the present invention provides granular biosulfur produced by the above biosulfur granulation method.

The present invention provides a method for granulating biosulfur that can control stability in water and provide slow-release sulfur fertilizer.

According to the method for granulating biosulfur of the present invention, the manufacturing period can be shortened compared to the conventional manufacturing method, the freeze-drying cost can be saved, and furthermore, the loss of raw materials during the process can be reduced.

Figure 1 shows electron micrographs of organic and inorganic sulfur. (a) is organic turmeric, (b) is inorganic turmeric.
Figure 2 shows the production process of biosulfur by microbial method.
Figure 3 shows a schematic diagram of the biosulfur granulation method according to Example 2 of the present invention.
Figure 4 shows photographs of granular biosulfur dried at 120°C for 30 minutes and granular biosulfur dried at room temperature for 96 hours.
Figure 5 is a photograph showing granular biosulfur by mixing ratio, (a) shows granular biosulfur produced by mixing 25% montmorillonite: 75% kaolinite, and (b) shows granular biosulfur produced by mixing 33.3% montmorillonite: 66.6% kaolinite.
Figure 6 shows the pH change measured while replacing 5 g of biosulfur granules prepared with a montmorillonite:kaolinite ratio of 33.3%:66.6% with 25 mL of ultrapure water every 4 to 24 hours.
Figure 7 shows the pH change measured while replacing 5 g of biosulfur granules prepared with a montmorillonite:kaolinite ratio of 25%:75% with 25 mL of ultrapure water every 4 to 24 hours.
Figure 8 shows the EC change measured by changing 5 g of biosulfur granules prepared with a montmorillonite:kaolinite ratio of 33.3%:66.6% into 25 mL of ultrapure water every 4 to 24 hours.
Figure 9 shows the EC change measured by changing 5 g of biosulfur granules prepared with a montmorillonite:kaolinite ratio of 25%:75% into 25 mL of ultrapure water every 4 to 24 hours.
Figure 10 shows the results of measuring the degree of disintegration of granular biosulfur in aqueous solution over time for each mixing ratio.
Figure 11 is a photograph of granular biosulfur after 5 hours when 100% montmorillonite was used at 120°C for 3 hours, and granular biosulfur after 2 weeks when a mixture of montmorillonite and kaolinite was used at 180°C for 3 hours at a ratio of 1:2. indicates.
Figure 12 shows the amount of sulfur elution measured by changing 5 g of biosulfur granules prepared with a montmorillonite:kaolinite ratio of 33.3%:66.6% into 25 mL of ultrapure water every 4 to 24 hours.
Figure 13 shows the amount of sulfur elution measured by changing 5 g of biosulfur granules prepared with a montmorillonite:kaolinite ratio of 25%:75% into 25 mL of ultrapure water every 4 to 24 hours.
Figure 14 shows the results of X-ray diffraction analysis of 33.3% montmorillonite:66.6% kaolinite.
Figure 15 shows the results of X-ray diffraction analysis of 25% montmorillonite:75% kaolinite.
Figure 16 is a schematic diagram showing the structures of kaolinite, montmorillonite, and granular biosulfur produced by the production method of the present invention.

Unless otherwise defined, technical and scientific terms used in this specification have the same meaning as commonly understood by an expert in the art. In addition, the experimental procedures specified in this specification are the same as those commonly performed in the technical field, unless specifically described.

Hereinafter, the present invention will be described in detail.

The present invention provides a method for granulating biosulfur that can control stability in water and provide slow-release sulfur fertilizer.

The granulation method of biosulfur according to an embodiment of the present invention is

1) Mixing liquid biosulfur with an inorganic adhesive to make dough;

2) Injecting the dough; and

3) It includes the step of drying the injection molded product,

The inorganic adhesive provides a method for granulating biosulfur, which can be used as a fertilizer.

The biosulfur of the present invention can use organic sulfur produced by microorganisms, and may preferably be produced using bacteria ( Thiobacillus spp ).

The organic sulfur has a nitrogen source or an oxygen source and is slightly alkaline and hydrophilic, so it can be mixed with other drugs. In addition, organic turmeric has a chain structure and a small particle size of 1 to 4㎛, so it is easily absorbed by mold of about 10㎛ and has excellent fungicidal power.

Unlike organic sulfur, inorganic sulfur (normal sulfur, petroleum sulfur) mainly uses a mixture of lime and sulfur and is manufactured through a chemical process. Because it is strongly alkaline, it is used by dissolving it in caustic soda, and its mixing with other drugs is limited. In addition, inorganic sulfur has a large particle size of 400 to 600 ㎛ with an agglomerated crystal structure. Figure 1 shows electron micrographs of organic and inorganic sulfur.

The biosulfur of the present invention is produced by converting hydrogen sulfide generated during incineration into sulfur through microbial metabolism, and Figure 2 shows the production process of biosulfur by this microbial method. Mixed natural gas is put into a gas scrubber, and hydrogen sulfide (H ₂ S) is absorbed using an alkaline solution, and purified gas is discharged. At this time, the precipitate of the alkaline solution that absorbed hydrogen sulfide is put into a bioreactor and air is injected to actively promote oxidation and microbial activity, and then biosulfur can be obtained by separating the biosulfur in a sulfur processor.

The inorganic adhesive of the present invention may be a clay mineral or a crystalline mineral, preferably a clay mineral, and more preferably a clay mineral with a 1:1 layered structure or a clay mineral with a 2:1 layered structure or these. It may be a mixture of

The clay mineral or crystalline mineral may be at least one selected from the group consisting of montmorillonite, bentonite, kaolinite, and zeolite, and is preferably montmorillonite or kaolinite, more preferably a mixture of montmorillonite and kaolinite.

The montmorillonite is a monoclinic mineral and a type of clay mineral. It has a hardness of 1 to 1.5, a specific gravity of 2 to 1.5, is white, gray, pink, blue, and green, and has the property of absorbing moisture to increase its volume by 7 to 10 times. It has high ion exchangeability, has adhesion at a water content of 150% to 500%, and has low internal friction resistance. It is produced by deterioration of aluminum-rich minerals or rocks, and its chemical composition is (Al, Mg). ₂ Si ₄ O ₁₀ (OH) ₂ 4H ₂ O.

The bentonite is a clay that mainly contains montmorillonite, a monoclinic mineral with a mica-like crystal structure, and has colors such as white, gray, light brown, and light green, and is used as a binder for castings, an additive for ceramic raw materials, and ointments. It is used in various fields such as base materials, and many contain quartz, feldspar, zeolite, etc., and its properties are similar to those of montmorillonite, such as adsorbing water to swell and having clear cation exchange properties.

The kaolinite is a type of kaolin mineral group and its chemical formula is [Al ₂ Si ₂ O ₅ (OH) ₄ ]. It is a 1:1 combination of silicate tetrahedral plate and aluminum octahedral plate, forming a hexagonal plate shape. In addition to being produced by hydrothermal action, kaolinite is made from primary minerals such as feldspar or 2:1 type clay minerals through weathering, and is widely distributed in soil and sediments. In particular, it forms the predominant type of clay in heavily weathered soils in tropical regions. It is a representative clay mineral in Korean soil.

The zeolite is a general term for minerals that are hydrates of aluminum silicate of alkali and alkaline earth metals. They are colorless and transparent or white translucent, and are also called zeolites. There are many types, but they have common characteristics such as high water content, crystalline properties, and acid phase. The hardness does not exceed 6, the specific gravity is about 2.2, and the main types include argillite, fisheye, chabazite, soda arsenite, helandite, stilbite, lomontite, and inesite, and basic igneous rocks such as basalt and pyroxene tuff. It is produced in cavities or fractures, and sometimes exists as a secondary mineral in granite and gneiss. In addition, it may be found in gold ore veins and other veins. In terms of the crystal structure, the bonds between each atom are loose, so even if the moisture filling the space is released with high heat, the skeleton remains intact, so it has the property of adsorbing other fine particles. It is used as an adsorbent and also as a molecular sieve to separate fine particles of different sizes.

The mixing ratio of the montmorillonite and kaolinite may be 1:1 to 1:3 parts by weight, and preferably 1:2 parts by weight.

Injection of the present invention may refer to any molding method that forms an article by injecting raw materials into a mold. Any commonly used injection molding machine can be used, and injection using a mold or syringe is preferred. The mold may be an aluminum tray.

Drying in the present invention can be done by a normal drying method rather than freeze-drying, and preferably by air drying or drying using a dryer.

The drying time may be 30 minutes to 24 hours, preferably 1 hour to 5 hours, and most preferably 1 hour. If the drying time is outside the above range, if the drying time is too short, the granules will easily break and the structure may be damaged. Sulfur can be unstable, and too long a time can be problematic in that manufacturing takes a long time and is expensive.

In addition, the drying temperature may be 50°C to 350°C, preferably 120°C to 180°C, and most preferably 180°C. If the drying temperature is outside the above range, too low a temperature may result in low hardness and stability against water. This is low, and if it exceeds 350°C, it can be problematic in that sulfur bonds are broken and sulfur cannot be adsorbed or stabilized in the structure or surface of the clay mineral and may evaporate.

A specific embodiment of the present invention is to mix the two clay minerals montmorillonite (MMT; montmorillonite) and kaolinite (Kao; kaolinite) used in the synthesis of granular biosulfur at 100:0, 75:25, 50:50, 33.3:66.6, 25:75. It was mixed with biosulfur raw materials at a wt% ratio and heat treated. To analyze the physicochemical properties of the granulated biosulfur, the hardness, stability in aqueous solution, pH, and electrical conductivity (EC) of the biosulfur were measured, and inductively coupled plasma analysis (ICP) was used to measure the amount of sulfur dissolved in the aqueous solution. The effectiveness of granular biosulfur as a fertilizer was confirmed through plasma analysis (EA) and elemental analysis (EA) to measure sulfur content. Additionally, an X-ray diffractometer (XRD) was performed to determine the crystalline phase of granular biosulfur.

As a result of measuring the physicochemical properties of granular biosulfur, compared to liquid biosulfur, pH slightly increased, alkalinity increased, and EC decreased by about 40-50%. In the case of EC, it was assumed that the sulfur component was stabilized within the granular structure during the heat treatment process during granular biosulfur synthesis.

In measuring the average hardness and disintegration in aqueous solution, the average hardness increased as the kaolinite content increased, and it was confirmed that the form of granular biosulfur was maintained for a long period of time in the aqueous solution. Through this, the effect of kaolinite added to improve stability and hardness in aqueous solution was confirmed.

As a result of measuring EC over time to see the change pattern of granular biosulfur in the soil, it was confirmed that there was little difference in pH over time, but EC decreased rapidly and maintained a certain amount over time. This means that the inorganic salt components of granular biosulfur are eluted consistently over time.

As a result of ICP, do.

As a result of XRD analysis to determine the structural characteristics of granular biosulfur, when comparing the The spacing also matched. Additionally, a peak representing the interlayer spacing between kaolinite and montmorillonite was observed in the XRD pattern of granular biosulfur. However, in the case of montmorillonite, the peak intensity tended to be lower than that of kaolinite.

As a result of EA analysis to determine the sulfur content of granular biosulfur, the sulfur content ranged from about 45 to 47%, a similar value to the sulfur content of 45 ± 3% used in manufacturing granular biosulfur. Through this, it was confirmed that there was almost no loss of sulfur during the granular biosulfur manufacturing process.

Therefore, in order to use the biosulfur of the present invention as a fast-acting fertilizer, the ratio of montmorillonite must be increased, and to use it as a slow-acting fertilizer, the montmorillonite:kaolinite ratio is used at a ratio of 1:2 or 1:3 by weight, so that it can be stably used as a sulfur fertilizer. It was confirmed that it can be used.

Hereinafter, the present invention will be explained in detail through the following examples and experimental examples.

However, the following examples and experimental examples only illustrate the present invention, and the content of the present invention is not limited to the following examples and experimental examples.

<Example 1> Production of granular biosulfur

The biosulfur used in the production of granular biosulfur of the present invention was a biosulfur raw material produced by Ecobio Holdings Co., Ltd. Since biosulfur is in a sticky suspension state, it was stirred thoroughly before use before the experiment to prevent the particles from settling and hardening over time. The physicochemical characteristics of liquid biosulfur are shown in Table 1 below.

Disclosure material pH EC
(dS·m ^-1 ) bio sulfur 8.60 63.15

pH and EC were measured by mixing the biosulfur stock solution with distilled water at a ratio of 1:5 (v/v) and shaking for 30 minutes using a pH meter and EC meter, respectively. It was confirmed that biosulfur contains 45±3% sulfur, pH is 8.60, and EC is 63.15 dSm ^-1 .

An appropriate amount of liquid biosulfur and Mixed. The amount of liquid biosulfur was mixed for each sample in consideration of the degree of calcination. To manufacture granules, the mixture was placed in a 60mL syringe, then injected into an aluminum tray, and heat treated in a furnace at 180°C for 1 hour. Figure 3 is a schematic diagram showing the granulation method of biosulfur.

1-1. Measuring the degree of bio-sulfur mixture dough according to the plasticity limit of each mineral

By adding 1 mL of liquid bio-sulfur to 15 g of each inorganic adhesive, the amount of bio-sulfur appropriate for kneading was measured.

Table 2 below shows the results.

Clay mineral (15g) Sulfur (mL) About the dough Kaolinite 27 Stiff 28 suitable 29 very watery Montmorillonite 31 Stiff 34 suitable Zeolite 28 Stiff

The measurement results showed that the appropriate amount of biosulfur required for dough was different within the plasticity limit of the inorganic adhesive. Therefore, it was confirmed that mixing 15 g of kaolinite with 28 mL of liquid biosulfur and mixing 15 g of montmorillonite with 34 mL of liquid biosulfur were the appropriate amounts needed for the dough.

1-2. mineral conditions

To determine the mineral mixing ratio of the present invention, montmorillonite and kaolinite were mixed in weight parts of 1:0, 3:1, 1:1, and 1:3, respectively, and pH and EC were measured.

Table 3 below shows the results.

MMT: Kao (4g) MMT(g) Kao(g) pH EC (μS/cm) 1:0 4 0 8.47 2091.5 3:1 3 One 7.32 2449.5 1:1 2 2 7.89 1584 1:3 One 3 7.57 559

If the pH is a strong acid below 5 or a strong base above 11, it is better to have it close to neutral as there may be problems with nutrient absorption. A high electrical conductivity (EC) indicates a large amount of ions, so the higher the EC, the faster it dissolves. do.

These results are due to the characteristics of the raw materials, montmorillonite and kaolinite, and confirm that the pH is close to neutral and the EC is below or near 2ds/m, making it suitable for use as a raw material in the manufacture of granules.

1-3. Comparison of stability according to drying temperature and drying time of montmorillonite

To confirm the stability of the montmorillonite of the present invention, the drying temperature was set to 120°C and room temperature, and the pH value was measured at drying times of 30 minutes, 5 hours, and 96 hours. Table 4 below shows the results.

clay mineral Sulfur (mL) drying temperature drying time pH Montmorillonite 34 120℃ 30 minutes 10.46 34 120℃ 5 hours 10.34 34 Room temperature (25℃) 96 hours 10.36

Figure 4 shows photographs of montmorillonite samples dried at 120°C for 30 minutes and montmorillonite samples dried at room temperature for 96 hours. It was confirmed that the room temperature dried sample had very low hardness and collapsed immediately when placed in water, so it could be used as a granule only when heat above a certain temperature was applied. The 120°C dried sample was somewhat lacking in stability in aqueous solution, so it was decided to mix it with kaolinite.

1-4. Mixing experiment of montmorillonite and kaolinite

After deciding to mix montmorillonite and kaolinite, to determine the mixing ratio, the montmorillonite:kaolinite ratio was 1:0 by weight. The ratios of 3:1, 1:1, and 1:3 were dried at 120°C for 1 hour and 3 hours, respectively, and pH and EC were measured. Table 5 below shows the results of drying at 120°C for 1 hour, and Table 6 shows the results of drying at 120°C for 3 hours.

MMT: Kao (28g) MMT(g) Kao(g) Sulfur (ml) pH EC(mS) 1:0 28 0 62 10.51 33 3:1 21 7 56 10.56 33 1:1 14 14 60 10.57 38 1:3 7 21 56 10.46 30.5

MMT: Kao (40g) MMT(g) Kao(g) Sulfur (ml) pH EC(mS) 1:0 40 0 69 10.20 22.5 3:1 30 10 67 10.30 29.5 1:1 20 20 64 10.30 27.5 1:3 10 30 63 10.39 35.5

The measurement results showed that there was no significant difference in pH and EC at 1 hour and 3 hours depending on the mixing ratio of montmorillonite and kaolinite. Therefore, it was confirmed that 1 hour was better than 3 hours in terms of process efficiency.

1-5. Determination of inorganic adhesive ratio and drying conditions

To determine the ratio of inorganic adhesive in the production of granular biosulfur, the ratio of montmorillonite:kaolinite was set to 100:0, 50:50, 25:75, and 75:25, and the drying temperature was set to 120℃ and 350℃ for 3 hours. Stability in water, pH, and EC were measured as characteristics of the manufactured particles. Table 7 below shows the granular characteristics according to the inorganic adhesive ratio and drying conditions.

Inorganic adhesive ratio (wt%)
(Montmorillonite: Kaolinite) drying time
and temperature stability in water pH
(1:5) EC
(dS/m) 100:0 120℃, 3 hours middle 10.2 4.5 350℃, 3 hours lowness 4.5
(incongruity) 8.1 50:50 120℃, 3 hours middle 10.5 25:75 10.4 6.1 75:25 10.3 6.6

As a result, when heated to 350°C, the pH was found to be very low to about 4.5. It is believed that as the temperature rises, the sulfur bonds in the chain are broken and it changes into sulfuric acid in the form of H ₂ SO ₄ . Therefore, it is important to maintain an appropriate temperature because sulfur, which is a raw material, is lost when heated to a temperature of about 350℃. Since the bonds of sulfur begin to break around 120℃, the appropriate temperature for bonding sulfur to the particles is around 120℃. It was confirmed that it was.

Granular biosulfur prepared with 25% montmorillonite (MMT): 75% kaolinite (Kao), 33.3% montmorillonite (MMT): 66.6% kaolinite (Kao) is shown in Figure 5.

<Example 2> Addition of other additives (water, NH4Cl) to montmorillonite and kaolinite

Water or NH ₄ Cl as other additives were added to the montmorillonite and kaolinite of the present invention, and pH and EC were measured according to drying time. Table 8 below shows the results.

Condition+B38:K44 MMT: Kao Kao(g) MMT(g) drying time Sulfur (ml) H ₂ O
(ml) NH ₄ Cl
(ml) pH EC
(mS) MMT + Kao
+sulfur 1:2 18.7 9.3 1hr 56 　 　 10.68 36.5 3hr 56 　 　 10.70 40.65 MMT + Kao +
sulfur+H ₂ O 1hr 30 10 　 10.20 25.15 3hr 30 10 　 9.76 30.85 MMT + Kao +
sulfur+
NH ₄ Cl 1hr 30 　 10 8.51 28.95 3hr 30 　 10 8.48 52.85

As a result, it was possible to manufacture granules when kneading the sulfur ratio by half and mixing it with water. Considering that the EC was lowered, it was determined that the sulfur ratio of the granules could be adjusted to some extent depending on the conditions. In addition, when NH ₄ Cl was added, the pH was found to be lowered to near neutral.

Therefore, it was confirmed that it can be used as a fertilizer even when various substances such as N sources other than biosulfur are added.

<Experimental Example 1> Measurement of physicochemical properties (pH, EC, hardness) of granular biosulfur

The physicochemical properties of granular biosulfur were confirmed through pH, EC, and hardness. pH and EC were measured by mixing granular biosulfur with distilled water at 1:5 (w/v) and shaking for 30 minutes using a pH meter and EC meter, respectively. For changes in pH and EC over time, ultrapure water was replaced at 4-hour intervals from 4 to 40 hours after analysis, and at 24-hour intervals for the next 96 hours. Figure 6 shows the pH change measured by changing 5 g of biosulfur granules prepared with a montmorillonite:kaolinite ratio of 33.3%:66.6% into 25 mL of ultrapure water every 4 to 24 hours, and Figure 7 shows the change in pH at a montmorillonite:kaolinite ratio of 25%. : Shows the pH change measured by changing 5g of biosulfur granules prepared at 75% into 25mL of ultrapure water every 4 to 24 hours. In addition, Figure 8 shows the change in EC measured by changing 5 g of biosulfur granules prepared with a montmorillonite:kaolinite ratio of 33.3%:66.6% into 25 mL of ultrapure water every 4 to 24 hours, and Figure 9 shows the montmorillonite:kaolinite ratio. This shows the EC change measured by changing 5g of biosulfur granules prepared at 25%:75% into 25mL of ultrapure water every 4 to 24 hours.

Hardness was measured by dividing the granular biosulfur into 20 equal parts and using a soil hardness meter (Push-Cone DIK-5553 Daiki Rika Kogyo Co., Japan). Table 9 below shows the results of measuring pH, EC, and hardness for each mixing ratio of granular biosulfur.

Sample MMT: Kao
(wt%) pH
(1:5) EC
(dS·m-1) average hardness A 100:0 9.50(±0.088*) 29.27(±0.024*) 8.2(±0.37*) B 75:25 10.17(±0.047*) 32.35(±0.14*) 8.8(±0.63*) C 50:50 10.07(±0.047*) 37.78(±0.15*) 9.0(±0.40*) D 33.3:66.6 10.74(±0.014*) 36.80(±0.25*) 13.3(±0.82*) E 25:75 10.60(±0.0047*) 34.03(±0.21*) 17.6(±0.98*) * SD: Standard Deviation

Compared to biosulfur before synthesis, pH was 9.50 (±0.062) for A, 10.17 (±0.033) for B, 10.07 (±0.033) for C, 10.74 (±0.01) for D, and 10.60 (±0.003) for E. It was measured to be about 1 to 2 degrees higher than liquid biosulfur.

For EC, A is 29.27 (±0.017) dSm-1, B is 32.35 (±0.1) dSm-1, C is 37.78 (±0.109) dSm-1, D is 36.80 (±0.18) dSm-1, and E is 34.03. (±0.15) dSm-1, a decrease of approximately 40 to 50% compared to liquid biosulfur.

The average hardness is 8.2 (±0.37) for A, 8.8 (±0.63) for B, 9.0 (±0.40) for C, 13.3 (±0.82) for D, and 17.6 (±0.98) for E. As the kaolinite content increases, the hardness increases. It was confirmed that there was an increase.

If the hardness is too low, there is a problem that it breaks due to impact when supplied as a fertilizer, and if the hardness is too high, it will continue to remain in the soil, so appropriate hardness is important, and it was judged that around 10 would be good. As a result of the measurement, it was confirmed that it could be used as a fertilizer because pH and EC did not significantly deviate from the appropriate standards.

<Experimental Example 2> Measurement of disintegration of granular biosulfur in aqueous solution

Measurement of disintegration in aqueous solution was performed by mixing granular biosulfur and distilled water at a ratio of 1:5 (w/v). Measurements were made at 10 minutes for 1 hour after dissolution, at 1-hour intervals for the next 5 hours, and then 1 day after dissolution. The degree of collapse was visually graded from 0 to 10.

The results of measuring the degree of disintegration in aqueous solution over time for each mixing ratio of granular biosulfur are shown in Figure 10. 0 to 2 indicates maintenance of the original form, 3 to 4 indicates approximately 30% dissolution, 5 to 6 indicates approximately 50% dissolution, 7 to 8 indicates approximately 70% dissolution, and 9 to 10 indicates complete dissolution. Table 10 below shows the results.

MMT + Kao + Bio sulfur (180℃, 1hr) 　 Collapse degree (0~10) MMT: Kao (wt%) (30g) 30min 60min 90min 120min 150min 180min 360min 1day 100:0 4 6 7 8 8 9 10 10 50:50 2 2 2 3 3 4 4 5 33.3:66.6 One 2 2 3 3 4 4 6 25:75 0 0 One One One One One 3 75:25 4 5 7 8 8 9 9 10

As a result of the measurements, all samples showed an increase in disintegration over time. A and B were measured as 4 30 minutes after dissolution, and A was measured as 10 6 hours after dissolution, when the sample was completely dissolved in the aqueous solution. 24 hours after dissolution, B was also measured as 10. C and D were measured as 1 to 2 30 minutes after dissolution, and were measured as 5 to 6 24 hours after dissolution, when 50% of the sample was dissolved. E remained at 0 even 1 hour after dissolution, indicating that the sample was not dissolved, and then rose slightly, measuring 3 24 hours after dissolution.

Photos of granular biosulfur after 5 hours when 100% montmorillonite was used at 120°C for 3 hours and granular biosulfur after 2 weeks when a mixture of montmorillonite and kaolinite were used at 180°C for 3 hours at a ratio of 1:2 are shown in Figure 11. indicated.

Through this, it was confirmed that stability against water could be increased or decreased by adjusting the drying temperature, time, and ratio of inorganic adhesive as needed. More specifically, drying for a short time at a drying temperature of around 120℃ and increasing the ratio of montmorillonite can lower water stability, while drying for a long time at a drying temperature of around 180℃ and increasing the ratio of kaolinite can reduce water stability. Stability can be improved.

<Experimental Example 3> Inductively Coupled Plasma Analysis (ICP) to measure sulfur dissolution over time from granular biosulfur

The sulfur content of granular biosulfur was measured using an elemental analyzer (EA), and the crystalline phase of granular biosulfur was identified through XRD analysis. ICP analysis was performed to measure the amount of sulfur dissolved in an aqueous solution of granular biosulfur. Granular biosulfur was mixed with ultrapure water at 1:5 (w/v), and the amount of sulfur leached was measured at 4-hour intervals for the first 40 hours and at 24-hour intervals for the next 96 hours. Figure 12 shows the amount of sulfur elution measured by changing 5 g of biosulfur granules prepared with a montmorillonite:kaolinite ratio of 33.3%:66.6% into 25 mL of ultrapure water every 4 to 24 hours, and Figure 13 shows the amount of sulfur dissolved at a montmorillonite:kaolinite ratio of 25%. : Indicates the amount of sulfur elution measured by changing 5g of biosulfur granules prepared at 75% into 25mL of ultrapure water every 4 to 24 hours.

As a result of the measurement, it was confirmed that the sulfur concentration in the aqueous solution decreased with time. When the sulfur concentration was measured 4 hours after dissolution in aqueous solution, D was measured at 2069.67ppm and E was measured at 2151.67ppm, with E being higher. After 8 hours of dissolution, D was 134.67ppm and E was 136.27ppm, which was confirmed to have decreased by about 93.5% and 93.7%, respectively. From 12 hours to 40 hours, the sulfur concentration decreased over time, and 64 hours after dissolution, the average sulfur concentration of D was 2.645 (±0.234) ppm and that of E was 4.525 (±0.392) ppm. The concentration was kept constant.

Therefore, it was confirmed that both of them can be used as slow-release sulfur fertilizers as sulfur is steadily eluted.

<Experimental Example 4> Elemental analysis (EA; Elemental Analyzer) to measure sulfur content of granular biosulfur

In order to measure the sulfur content of the granular biosulfur of the present invention, the granular biosulfur prepared in Example 1 was finely ground and measured using an elemental analyzer.

Table 11 below shows the results of elemental analysis (EA) by mixing ratio of the biosulfur phase.

Sample MMT: Kao
(wt%) S
(%) D 33.3:66.6 47.23 E 25:75 45.57

The sulfur contents of D and E were 47.23% and 45.57%, respectively, which were similar to the sulfur content of 45±3% used in the production of granular biosulfur. Therefore, the potential as a slow-release fertilizer was confirmed when the ratio of montmorillonite and kaolinite was 1:2 or 1:3.

<Experimental Example 5> Crystalline phase analysis of granular biosulfur

X-ray diffraction analysis

An X-ray diffractometer (XRD) was performed to determine the crystalline phase of granular biosulfur. The results are shown in Figures 14 and 15.

Figure 14 shows the results of X-ray diffraction analysis of 33.3% montmorillonite: 66.6% kaolinite, and Figure 15 shows the results of X-ray diffraction analysis of 25% montmorillonite: 75% kaolinite.

Samples were measured using a, b, c, d, and e. Looking at c and e, it can be seen that the XRD pattern of granular biosulfur has peaks that are a mixture of the patterns of liquid biosulfur and clay minerals. Looking at a, c, and e, the basal spacing was measured to be the same at 22.98°, which is the peak representing the interlayer distance of sulfur, at 0.387nm. In addition, since the peaks of a, which represent the structural characteristics of sulfur, were consistent with c and e, it could be assumed that the structure was stably maintained within the heat treatment temperature (180°C) and no denaturation occurred. b and d are clay mineral mixtures, and peaks with structural characteristics of montmorillonite and kaolinite were observed. At the peaks of c and e, peak values presumed to be kaolinite were measured at 12.16° (0.727 nm) and 12.2° (0.725 nm), respectively, and a faint peak presumed to be montmorillonite was measured at 5.52° (1.6 nm) of e. .

Therefore, it was confirmed that the structures of sulfur, montmorillonite, and kaolinite were maintained in the biosulfur granules of the present invention.

Structure of granular biosulfur

The structures of kaolinite, montmorillonite, and biosulfur produced by the biosulfur production method of the present invention were observed.

Figure 16 is a schematic diagram showing the structures of kaolinite, montmorillonite, and granular biosulfur produced by the production method of the present invention.

The kaolinite and montmorillonite used in the present invention were found to have a layered structure. As a result, sulfur particles exist between each layer in the structure of kaolinite and montmorillonite, and sulfur is slowly eluted from the biosulfur of the present invention. It was confirmed that it can have complete efficacy.

In conclusion, it was found that the clay minerals used in the synthesis of granular biosulfur not only help with granulation but also have a role in eluting the clay minerals and adsorbed sulfur components over a constant, long-term period. Through this, the possibility of using granular biosulfur as a slow-release fertilizer was confirmed.

The present invention is expected to be of great help to farmers who grow lilies and other crops that require a lot of sulfur fertilization by synthesizing liquid biosulfur with clay minerals, a natural mineral, in an environmentally friendly manner. In addition, it can provide a convenient means for organic farmers by using eco-friendly granular biosulfur fertilizer, breaking away from the custom of applying large amounts of chemical fertilizers in conventional agriculture.

Claims (14)

As a bio granulation method,
1) Mixing liquid biosulfur with an inorganic adhesive to make dough;
2) Injecting the dough; and
3) It includes the step of drying the injection molded product,
A method for granulating biosulfur, characterized in that the inorganic adhesive can be used as a fertilizer.
The method of granulating biosulfur according to claim 1, wherein the biosulfur is organic sulfur.
The method of granulating biosulfur according to claim 1, wherein the inorganic adhesive is a clay mineral with a 1:1 layered structure, a clay mineral with a 2:1 layered structure, or a mixture thereof.
The method of granulating biosulfur according to claim 3, wherein the inorganic adhesive is at least one selected from the group consisting of montmorillonite, bentonite, kaolinite, and zeolite.
The method of granulating biosulfur according to claim 4, wherein the inorganic adhesive is a mixture of montmorillonite and kaolinite.
The method of granulating biosulfur according to claim 5, wherein the mixing ratio of montmorillonite and kaolinite is 1:2.
The method of granulating biosulfur according to claim 1, wherein the injection is performed using a mold or syringe.
The method of granulating biosulfur according to claim 7, wherein the mold is an aluminum tray.
The method of granulating biosulfur according to claim 1, wherein the drying is performed at a temperature of 50°C to 350°C.
The method of granulating biosulfur according to claim 1, wherein the drying is performed for 30 minutes to 24 hours.
Granular biosulfur produced by the production method of claims 1 to 10.
The granular biosulfur according to claim 11, wherein the granular biosulfur has improved stability in an aqueous solution.
The granular biosulfur according to claim 11, wherein the granular biosulfur can be used as a slow-release fertilizer by controlling the amount of sulfur leaching.
The granular biosulfur according to claim 13, wherein the slow release effect is such that sulfur dissolution lasts for more than 6 months.