阅读说明：本技术 具有内嵌粉末组合物的增效肥料 (Enhanced fertilizer with embedded powder composition ) 是由 拉贾马莱斯沃拉玛·科里佩利 拉维·赫格德 钱德拉·莫汉纳 拉达·阿查纳特 沙米克·古普塔 于 2018-04-12 设计创作，主要内容包括：本文所述的肥料颗粒包括粉末组合物,该粉末组合物可以包含一种或多于一种尿素酶抑制剂和/或硝化抑制剂以及嵌入固体尿素基质内的填料。生产肥料颗粒的方法涉及在足以形成粉末组合物嵌入固体尿素基质中的肥料颗粒的条件下,使可包含一种或多于一种尿素酶抑制剂和/或硝化抑制剂和填料的粉末组合物与熔融尿素接触。(The fertilizer granules described herein include powder compositions that may include one or more urease inhibitors and/or nitrification inhibitors and a filler embedded within a solid urea matrix. A method of producing a fertilizer granule involves contacting a powder composition, which may comprise one or more than one urease inhibitor and/or nitrification inhibitor and a filler, with molten urea under conditions sufficient to form a fertilizer granule with the powder composition embedded in a solid urea matrix.)

1. A fertilizer granule comprising a powder composition distributed in a solid urea matrix, wherein the powder composition comprises a filler, and at least one of a urease inhibitor and/or a nitrification inhibitor, wherein the urease inhibitor or nitrification inhibitor is less than 20 wt% of the powder composition.

2. The fertilizer granule of claim 1, wherein the urease inhibitor is less than 5 wt% of the powder composition and the nitrification inhibitor is less than 10 wt% of the powder composition.

3. The fertilizer granule of claim 1, wherein the filler comprises from 10 wt% to 99 wt% of the powder composition, and the filler is further defined as an antidegradant.

4. The fertilizer granule of claim 1, wherein the powder composition is 2% to 8% by weight of the granule.

5. The fertilizer granule of claim 1, wherein the urease inhibitor is N- (N-butyl) thiophosphoric triamide (NBTPT) and the nitrification inhibitor is dicyandiamide (DCD).

6. The fertilizer granule of claim 1, wherein the filler comprises one or more of silica, distillers dried grains with solubles (DDGS), kaolin, bentonite, rice bran, plaster of paris, flour, biodegradable bleached wheat flour, starch, or gluten.

7. The fertilizer granule of claim 1, wherein the powder composition further comprises a pH buffer comprising chalk powder, CaCO₃、MgO、KH₂PO₄、NaHCO₃、Na₂CO₃、K₂CO₃Or MgCO₃One or more than one.

8. The fertilizer granule of claim 1, wherein the granule is substantially homogeneous.

9. The fertilizer granule of claim 1, wherein the granule has a diameter of about 2mm to 4 mm.

10. The fertilizer granule of claim 1, wherein the granule comprises 2 to 8 wt% filler, 0.05 to 0.11 wt% NBTPT, 0.5 to 2 wt% DCD, 2 to 8 wt% pH buffer, and 92 to 98 wt% urea.

11. The fertilizer granule of claim 1, having less than 20% by weight nitrogen loss from the fertilizer granule via volatilization of ammonia after exposure to greenville soil for 20 days.

12. The fertilizer granule of claim 1, wherein at least 90% of the urease inhibitor remains after the fertilizer granule is stored in the closed container at 22 ℃ for 30 days.

13. The fertilizer granule of claim 1, comprising NBTPT and n-butylamine, wherein the weight ratio of NBTPT to n-butylamine is from about 30:1 to 15: 1.

14. A fertilizer granule comprising a powder composition distributed throughout a solid urea matrix, wherein the powder composition comprises a filler and NBTPT, and wherein NBTPT is less than 5 wt% of the powder composition.

15. A method of preparing a granular fertilizer composition, the method comprising:

a) providing a powder composition comprising a powdered filler and at least one of powdered N- (N-butyl) thiophosphoric triamide (NBTPT) or powdered dicyandiamide (DCD); and

b) contacting the powder composition with a composition comprising molten urea under conditions sufficient to form a plurality of solid particles comprising the powder composition and solid urea.

16. The method of claim 15, wherein step (b) comprises spraying the composition comprising molten urea onto the powder composition while agitating the powder composition in a granulation apparatus.

17. The method of claim 15, wherein the powder composition comprises no more than 5% by weight NBTPT or no more than 30% by weight DCD.

18. The method of claim 15, wherein after step (b), the powder composition is distributed throughout the solid particles.

19. The method of claim 15, wherein the powder composition further comprises a pH buffer comprising chalk powder, CaCO₃、MgO、KH₂PO₄、NaHCO₃、Na₂CO₃、K₂CO₃Or MgCO₃One or more than one.

20. The method of claim 15, wherein the solid particles comprise 2 to 8 wt% filler, 0.05 to 0.11 wt% NBTPT, 0.5 to 2 wt% DCD, 2 to 8 wt% pH buffer, and 92 to 98 wt% urea.

Background

A. Field of the invention

The present invention relates generally to fertilizer compositions comprising urease inhibitors and/or nitrification inhibitors. The inhibitor may be contained in a powder composition comprising at least a filler and distributed in a solid urea matrix.

B. Description of the related Art

To increase crop yields and meet the increasing demand of the population, more fertilizers are used in agriculture. However, continued use of fertilizers can result in nutrient imbalances and a decrease in soil fertility. In addition, since urea fertilizers are rapidly hydrolyzed and nitrified in soil by soil bacteria, the widespread use of urea fertilizers can lead to deterioration of soil health and other environmental problems, such as greenhouse gas emissions and groundwater pollution.

The urea enzyme inhibitor and the nitrification inhibitor are added into the fertilizer to offset the hydrolysis and nitrification of urea in soil. Urease inhibitors reduce the amount of urea hydrolysis and thus the amount of nitrogen lost via ammonia volatilization. Nitrification inhibitors can reduce the rate of conversion of ammonium salts to nitrates, which also reduces the amount of nitrogen lost. Besides urea, the nitrification inhibitor can also effectively improve the utilization rate of various nitrogen fertilizers.

Although urease inhibitors and nitrification inhibitors have been used in fertilizers to address the problem of urea hydrolysis and nitrification, there are certain difficulties with the use of these inhibitors. One problem is that certain inhibitors are sensitive to heat, which complicates the production of fertilizers containing such inhibitors. For example, the addition of heat-sensitive inhibitors to molten urea prior to granulation can result in substantial degradation of the inhibitor, as described in Soil utilization and Management (Soil Use & Management)24:246 (2008). To compensate for this problem, some fertilizer manufacturers may add an excess of inhibitor to the urea melt, such as US2015/0101379 to Gabrielson et al. This approach increases the production cost of the fertilizer and still results in substantial thermal degradation of the inhibitor when exposed to molten urea.

Disclosure of Invention

The following discloses a solution to the above-mentioned problem. In some embodiments, the solution consists in providing fertilizer granules with urease inhibitors and/or nitrification inhibitors (also collectively referred to herein as "nitrogen stabilizers"), which may be contained in a powder composition distributed throughout a solid urea matrix. The powder composition may also comprise at least one filler material, which may also be defined as an antidegradant. Without wishing to be bound by theory, it is believed that the filler materials disclosed herein may protect the nitrogen stabilizer during the manufacturing process of the fertilizer granule by absorbing heat, dispersing heat, and/or isolating the inhibitor from the heat of the molten urea. A method of manufacturing a fertilizer granule involves providing a powder composition that may include one or more than one inhibitor and a filler, and fattening the powder composition with a molten urea composition in a granulation apparatus. This process has advantages over prior art processes because of its low cost and low complexity, while also protecting the nitrogen stabilizer from thermal degradation more effectively than processes involving the addition of nitrogen stabilizers to molten urea prior to granulation.

Disclosed herein is a fertilizer granule that can comprise a powder composition distributed in a solid urea matrix, wherein the powder composition can comprise a filler, and at least one of a urease inhibitor and/or a nitrification inhibitor, wherein the urease inhibitor is less than 20 wt% of the powder composition when the urease inhibitor is present, and the nitrification inhibitor is 10 wt% to 50 wt% of the powder composition when the nitrification inhibitor is present. A particular advantage of the fertilizer granules described herein is that, because the urease inhibitor is contained in a powder composition that may contain a filler, the fertilizer granules described herein may be manufactured using less urease inhibitor than conventional fertilizer granules, which may also be defined as an antidegradant in some embodiments. When present, the urease inhibitor may be about 0.1 wt% to 19.9 wt% or about 0.1 wt%, 0.5 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 19.5 wt%, or 19.9 wt% of the powder composition or between any two of these values. When present, the nitrification inhibitor may be about 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 30%, 35%, 40%, 45%, or 50% by weight of the powder composition, or between any two of these values. In some embodiments, both inhibitors are present, and the combined amount of urease inhibitor and nitrification inhibitor is about 0.1 wt% to 50 wt% or about 0.1 wt%, 0.5 wt%, 1.0 wt%, 2.0 wt%, 3.0 wt%, 4.0 wt%, 5.0 wt%, 6.0 wt%, 7.0 wt%, 8.0 wt%, 9.0 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, or 50 wt% of the powder composition, or between any two of these values. In a preferred embodiment, the urease inhibitor is less than 5% by weight of the powder composition and the nitrification inhibitor is less than 25% by weight of the powder composition. In some embodiments, the urease inhibitor is N- (N-butyl) thiophosphoric triamide (NBTPT). In some embodiments, the nitrification inhibitor is dicyandiamide (DCD). The powder composition distributed in the solid urea matrix may be distributed throughout the solid urea matrix, which means that no substantial part of the powder composition is present in the solid urea matrix, or is present at all. In other embodiments, a portion of the solid urea matrix is substantially free of the powder composition, while another portion of the solid urea matrix has the powder composition distributed therein.

In some embodiments, the powder composition distributed in the solid urea matrix may comprise a urease inhibitor and not a nitrification inhibitor. In some embodiments, the urease inhibitor is about 0.1 wt% to 5 wt% of the powder composition or is about 0.1 wt%, 0.5 wt%, 1.0 wt%, 1.5 wt%, 2.0 wt%, 2.5 wt%, 3.0 wt%, 3.5 wt%, 4.0 wt%, 4.5 wt%, or 5.0 wt% of the powder composition or between any two of these values.

In some embodiments, the powder composition distributed in the solid urea matrix may comprise a nitrification inhibitor and not comprise a urease inhibitor. In some embodiments, the urease inhibitor is about 0.1 wt% to 10 wt% of the powder composition or is about 0.1 wt%, 0.5 wt%, 1.0 wt%, 2.0 wt%, 3.0 wt%, 4.0 wt%, 5.0 wt%, 6.0 wt%, 7.0 wt%, 8.0 wt%, 9.0 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, or 50 wt% of the powder composition or is between any two of these values.

In some embodiments, the urease inhibitor may be NBTPT, which is about 0.05% to 0.11% by weight of the fertilizer granule. In some embodiments, the urease inhibitor is about 0.01 wt%, 0.02 wt%, 0.03 wt%, 0.04 wt%, 0.05 wt%, 0.06 wt%, 0.07 wt%, 0.08 wt%, 0.09 wt%, 0.10 wt%, 0.11 wt%, 0.12 wt%, 0.13 wt%, 0.14 wt%, 0.15 wt%, 0.16 wt%, 0.17 wt%, 0.18 wt%, 0.19 wt%, 0.20 wt%, 0.30 wt%, 0.40 wt%, or 0.50 wt% of the fertilizer particle, or between any two of these values.

In some embodiments, the nitrification inhibitor may be DCD, from about 0.5 wt% to 10 wt% of the fertilizer granule or at about 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1.0 wt%, 1.1 wt%, 1.2 wt%, 1.3 wt%, 1.4 wt%, 1.5 wt%, 1.6 wt%, 1.7 wt%, 1.8 wt%, 1.9 wt%, 2.0 wt%, 2.1 wt%, 2.2 wt%, 2.3 wt%, 2.4 wt%, 2.5 wt%, 2.6 wt%, 2.7 wt%, 2.8 wt%, 2.9 wt%, 3.0 wt%, 3.5 wt%, 4.0 wt%, 4.5 wt%, 5.5 wt%, 6.0 wt%, 6.5 wt%, 7.0 wt%, 7.5 wt%, 8.0 wt%, 8.5 wt%, 9.5 wt%, 10 wt% or any value in between these or other values. In embodiments including both NBTPT and DCD in the fertilizer granule, the combined amount of these inhibitors may be about 0.1 wt% to 15 wt% of the fertilizer granule or about 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1.0 wt%, 1.1 wt%, 1.2 wt%, 1.3 wt%, 1.4 wt%, 1.5 wt%, 1.6 wt%, 1.7 wt%, 1.8 wt%, 1.9 wt%, 2.0 wt%, 2.1 wt%, 2.2 wt%, 2.3 wt%, 2.4 wt%, 2.5 wt%, 2.6 wt%, 2.7 wt%, 2.8 wt%, 2.9 wt%, 3.0 wt%, 3.1 wt%, 3.2 wt%, 3.3.3 wt%, 3.4 wt%, 3.5 wt%, 3.6 wt%, 3.7 wt%, 2.8 wt%, 2.9 wt%, 3.0 wt%, 3.1 wt%, 3.2 wt%, 3.3.3.3.3.3.3.4 wt%, 3.5 wt%, 3.6 wt%, 3.7 wt%, 3.8 wt%, 3.9 wt%, 5.0 wt%, 6.0 wt%, 7.0 wt%, 8.0 wt%, 9.0 wt%, or 10.0 wt%, or between any two of these values.

The amount of filler may be about 10% to 99% by weight of the powder composition distributed within the solid urea matrix. In some embodiments, the filler is also defined as an antidegradant. In some embodiments, the filler is about 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 99 weight percent or between any two of these values of the powder composition. The filler may also be about 2% to 8% by weight of the fertilizer granule. In some embodiments, the filler is about 0.5 wt%, 1.0 wt%, 1.5 wt%, 2.0 wt%, 2.5 wt%, 3.0 wt%, 3.5 wt%, 4.0 wt%, 4.5 wt%, 5.0 wt%, 5.5 wt%, 6.0 wt%, 6.5 wt%, 7.0 wt%, 7.5 wt%, 8.0 wt%, 8.5 wt%, 9.0 wt%, 9.5 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, or 20 wt% of the fertilizer particle or between any two of these values. In some embodiments, the filler may comprise one or more of silica, distillers dried grains with solubles (DDGS), kaolin, bentonite, rice bran, plaster of paris, flour, biodegradable bleached wheat flour, starch, or gluten. The inclusion of fillers, especially antidegradants, in the fertilizer granules described herein helps to prevent thermally unstable urease inhibitors from degrading during the manufacturing process, thereby allowing the addition of less urease inhibitor to achieve the same or better effective NBTPT concentration in the final fertilizer granule.

The powder composition distributed in the solid urea matrix may also comprise a pH buffer. One of ordinary skill in the art will readily recognize that a variety of different pH buffers may be used. In some embodiments, the pH buffering agent may comprise chalk powder, CaCO₃、MgO、KH₂PO₄、NaHCO₃、Na₂CO₃、K₂CO₃Or MgCO₃One or more than one. The pH buffer may be about 2 wt% to 8 wt% of the fertilizer particle, or about 0.5 wt%, 1.0 wt%, 1.5 wt%, 2.0 wt%, 2.5 wt%, 3.0 wt%, 3.5 wt%, 4.0 wt%, 4.5 wt%, 5.0 wt%, 5.5 wt%, 6.0 wt%, 6.5 wt%, 7.0 wt%, 7.5 wt%, 8.0 wt%, 8.5 wt%, 9.0 wt%, 9.5 wt%, or 10 wt% of the particle, or between any two of these values.

In some embodiments, the fertilizer granules are substantially homogeneous. As used herein, a fertilizer granule is substantially homogeneous if the solid urea matrix is continuous and extends throughout the granule, even if some portions of the solid urea matrix have a higher concentration of powder composition granules than other portions of the solid urea matrix. As an illustrative example, a fertilizer particle is not substantially homogeneous if the fertilizer particle has a core-shell structure in which the core particle is surrounded by a solid urea composition having a different formulation than the core particle. In some embodiments of the fertilizer granule, the solid urea matrix is distributed throughout the fertilizer granule.

In some embodiments, the fertilizer granules are about 2mm to 4mm in diameter. The diameter may also be 0.5mm, 1.0mm, 1.5mm, 2.0mm, 2.5mm, 3.0mm, 3.5mm, 4.0mm, 4.5mm, 5.0mm, 5.5mm, 6.0mm, 6.5mm, 7.0mm, 7.5mm, 8.0mm, 8.5mm, 9.0mm, 9.5mm, or 10mm or between any two of these values.

In some embodiments, the powder composition distributed within the particles is from 2% to 8% by weight of the particles. The powder composition may also be 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 percent by weight of the particle or between any two of these values.

In some embodiments, the fertilizer granule may contain from about 92 wt% to 98 wt% urea or about 71 wt%, 72 wt%, 73 wt%, 74 wt%, 75 wt%, 76 wt%, 77 wt%, 78 wt%, 79 wt%, 80 wt%, 81 wt%, 82 wt%, 83 wt%, 84 wt%, 85 wt%, 86 wt%, 87 wt%, 88 wt%, 89 wt%, 90 wt%, 91 wt%, 92 wt%, 93 wt%, 94 wt%, 95 wt%, 96 wt%, 97 wt%, 98 wt%, 99 wt%, or 99.5 wt% urea or between any two of these values.

In some embodiments, the fertilizer granule may contain 2 to 8 wt% filler, 0.05 to 0.11 wt% NBTPT, 0.5 to 2 wt% DCD, 2 to 8 wt% pH buffer, and 92 to 98 wt% urea.

Also disclosed is a fertilizer granule that may comprise a powder composition distributed throughout a solid urea matrix, wherein the powder composition may comprise a filler and NBTPT, and wherein NBTPT is less than 5 wt% of the powder composition. In some embodiments, the filler is also defined as an antidegradant.

Embodiments of the fertilizer granules disclosed herein may be characterized by having stability to nitrogen in the granules when exposed to soil. In some embodiments, less than 20% by weight of the nitrogen in the granular fertilizer is lost via ammonia volatilization after exposure to greenville soil for 20 days. In some embodiments, the amount of nitrogen in the granular fertilizer that is lost via ammonia volatilization after 20 days of exposure to soil is less than 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 wt.%, or between any two of these values. In some embodiments, the amount of nitrogen in the granular fertilizer lost via ammonia volatilization after 20 days of exposure to greenville soil is less than 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 percent by weight, or between any two of these values. In some embodiments, less than 20% by weight of nitrogen is lost in the granular fertilizer after 20 days of exposure to clauli soil. In some embodiments, the amount of nitrogen lost in the granular fertilizer after 20 days of exposure to clauli soil is less than 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 weight percent, or between any two of these values.

Embodiments of the fertilizer granules disclosed herein can also be characterized by the stability of urease inhibitors, such as NBTPT, in the granules. This can be measured by a stability test which involves measuring the concentration of urease inhibitor in the granules before and after storage under controlled conditions for a certain period of time. In some embodiments, at least 90% of the urease inhibitor remains after 30 days of storage of the fertilizer granules in the closed container at 22 ℃ as compared to the concentration measured before storage of the granules in the closed container. In some embodiments, the fertilizer granule retains at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% of the urease inhibitor, or a residual amount between any two of these values.

The effect of antidegradants on the stability of urease inhibitors during production can be determined by measuring the amount of inhibitor present in the fertilizer granules at different times after granule formation and comparing it to the amount initially added during manufacture. For example, if the amount of NBTPT added is large enough that the fertilizer granule eventually contains 0.2 wt% NBTPT without any degradation during production, the stability of NBTPT during production can be determined by comparing the measured amount of NBTPT in the fertilizer with the "expected" or "raw" value of 0.2 wt%. The manufacturing process and the fertilizer composition protected against degradation will result in fertilizer particles with a higher content of NBTPT relative to the amount added during the manufacturing process. In some embodiments, the fertilizer granule of the present invention has at least 80%, 85%, 90%, 95%, or 99% of the amount of virgin NBTPT remaining. Embodiments of the fertilizer granule of the present invention may also be characterized by the amount of NBTPT degradation products present in the fertilizer granule. In some embodiments, the weight ratio of NBTPT to all NBTPT degradation products in the fertilizer granule of the invention is about 100:1, 50:1, 40:1, 30:1, 20:1, 15:1, 10:1, 9:1, 8:1, 7:1, 6:1, or 5:1, or between any two of these values. In some embodiments, the fertilizer particles of the present invention have less than about 0.005 wt%, 0.006 wt%, 0.007 wt%, 0.008 wt%, 0.009 wt%, 0.010 wt%, 0.011 wt%, 0.012 wt%, 0.013 wt%, 0.014 wt%, 0.015 wt%, 0.016 wt%, 0.017 wt%, 0.018 wt%, 0.019 wt%, 0.020 wt%, 0.025 wt%, 0.030 wt%, or 0.040 wt%, or a NBTPT degradation product between any two of these values, relative to the weight of the entire fertilizer particle. One particular product of NBTPT degradation is n-butylamine. In some embodiments, the weight ratio of NBTPT to n-butylamine in the fertilizer granules of the present invention is at least about 200:1, 150:1, 100:1, 75:1, 60:1, 50:1, 40:1, 30:1, 20:1, 15:1, 10:1, 9:1, 8:1, 7:1, 6:1, or 5:1, or between any two of these values. In some embodiments, the amount of n-butylamine in the fertilizer particles of the present invention is less than about 0.001 wt%, 0.002 wt%, 0.003 wt%, 0.004 wt%, 0.005 wt%, 0.006 wt%, 0.007 wt%, 0.008 wt%, 0.009 wt%, 0.010 wt%, 0.011 wt%, 0.012 wt%, 0.013 wt%, 0.014 wt%, 0.015 wt%, 0.016 wt%, 0.017 wt%, 0.018 wt%, 0.019 wt%, 0.020 wt%, 0.025 wt%, 0.030 wt%, or 0.040 wt%, or between any two of these values. In some embodiments, the amounts and weight ratios in this paragraph refer to values 24 hours after fertilizer granules are made by, for example, a granulation process; in some embodiments, the specified amounts and weight ratios are values 30, 60, or 90 days after the fertilizer granule is made.

Also disclosed is a method of preparing a granular fertilizer composition by: (a) providing a powder composition, which may comprise a powdered filler, and at least one of a powdered urease inhibitor or nitrification inhibitor; and (b) contacting the powder composition with a composition that may comprise molten urea under conditions sufficient to form a plurality of solid particles that may comprise the powder composition and solid urea. In some embodiments, after step (b), the solid particles may comprise a powder composition distributed within the solid particles and/or distributed throughout the solid particles. In some embodiments, the contacting of step (b) comprises spraying the molten urea composition onto the powder composition while agitating the powder composition in a granulation device. The powdered urease inhibitor may comprise about 0.1% to 30% by weight of the powder composition of step (a). In some embodiments, the urease inhibitor is about 0.1% to 5% by weight of the powder composition or is a powderAbout 0.1 wt%, 0.5 wt%, 1.0 wt%, 1.5 wt%, 2.0 wt%, 2.5 wt%, 3.0 wt%, 3.5 wt%, 4.0 wt%, 4.5 wt%, or 5.0 wt% of the composition, or between any two of these values. The amount of urease inhibitor required in the process of manufacturing the fertilizer granule is much lower than what is normally required. In conventional processes, an excess of a heat-labile urease inhibitor, such as NBTPT, is used to compensate for thermal degradation of the inhibitor during the manufacturing process. However, less NBTPT needs to be added during the manufacturing process described herein due to the effect of the filler material to protect the NBTPT from degradation during the manufacturing process. The powdered nitrification inhibitor may be about 0.1% to 50% by weight of the powder composition of step (a) or between any two of these values. In some embodiments, the powdered nitrification inhibitor may be about 0.1%, 0.5%, 1.0%, 2.0%, 3.0%, 4.0%, 5.0%, 6.0%, 7.0%, 8.0%, 9.0%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 25%, 30%, 35%, 40%, 45%, or 50% by weight of the powder composition, or between any two of these values. In some embodiments, the powder composition may further comprise a pH buffer comprising chalk powder, CaCO₃、MgO、KH₂PO₄、NaHCO₃、Na₂CO₃、K₂CO₃Or MgCO₃One or more than one. In some embodiments, the solid particulate may contain 2 to 8 wt% filler, 0.05 to 0.11 wt% NBTPT, 0.5 to 2 wt% DCD, 2 to 8 wt% pH buffer, and 92 to 98 wt% urea. In addition, all of the ingredients and amounts of the fertilizer granules described herein can be used in the process of making the fertilizer granules described herein.

In some embodiments of the method of making a fertilizer granule, no urease inhibitor is added to the molten urea composition prior to step (b), or no nitrification inhibitor is added to the molten urea composition prior to step (b). In some embodiments, neither the urease inhibitor nor the nitrification inhibitor is added to the molten urea composition prior to performing step (b). In some embodiments, the nitrification inhibitor is added to the molten urea composition prior to performing step (b).

In some embodiments, the method of manufacturing a fertilizer granule results in a reduced level of degradation of the nitrogen stabilizer as compared to a method in which the nitrogen stabilizer is added to molten urea prior to granulation, or as compared to a method in which no filler or anti-degradation agent is used. This can be measured by monitoring the nitrogen stabilizer concentration, for example by HPLC. It can also be measured by monitoring the amount of degradation products of the nitrogen stabilizer. In some embodiments, the method of making a fertilizer granule reduces degradation of a nitrogen fertilizer by about 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, or 99%, or between any two of these values.

In some embodiments, the amount of filler in the powder composition of step (a) is an amount effective to inhibit thermal degradation of the nitrogen stabilizer, e.g., NBTPT, in the process of making the fertilizer particles. In some embodiments, the amount of filler used is effective to inhibit thermal degradation of the nitrogen stabilizer by 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, or 99% relative to a similar fertilizer manufacturing process that does not use a filler, or relative to a fertilizer granule manufacturing process in which a nitrogen stabilizer is added to the molten urea prior to granulation. In some embodiments, the effective amount is about 20, 30, 40, 50, 60, 70, 80, 90, 95, or 99 weight percent of the powder composition.

Also disclosed herein is a powder composition that can comprise at least one of a nitrification inhibitor and a urease inhibitor, including combinations thereof, and at least one filler, wherein the urease inhibitor can comprise less than 20% by weight of the powder composition when the urease inhibitor is present, and the nitrification inhibitor can comprise about 10% to 50% by weight of the powder composition when the nitrification inhibitor is present. In some embodiments, the urease inhibitor is NBTPT. In some embodiments, the nitrification inhibitor is DCD. The inhibitor may be present in the powder composition in the amounts described above for the powder composition in the fertilizer granule. Fillers may also be defined as antidegradants and may be present in the amounts described above for the powder composition in the fertilizer granule. The powder composition may further comprise a pH buffer in an amount of about 1 wt% to 70 wt% or about 1 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt% or 70 wt% of the powder composition or between any two of these values. The powder composition may be included in a fertilizer composition, which may include a powder composition included in a fertilizer granule or distributed in or throughout a solid urea matrix in a fertilizer composition. The powder composition may also be used in the method of making fertilizer granules described herein.

The following embodiments 1 to 20 of the present invention are also disclosed. Embodiment 1 is a fertilizer granule comprising a powder composition distributed in a solid urea matrix, wherein the powder composition comprises a filler, and at least one of a urease inhibitor and/or a nitrification inhibitor, wherein the urease inhibitor or nitrification inhibitor is less than 20 wt% of the powder composition. Embodiment 2 is the fertilizer granule of embodiment 1, wherein the urease inhibitor is less than 5 weight percent of the powder composition and the nitrification inhibitor is less than 10 weight percent of the powder composition. Embodiment 3 is the fertilizer granule of embodiment 1 or 2, wherein the filler comprises 10% to 99% by weight of the powder composition, and is further defined as an antidegradant. Embodiment 4 is the fertilizer granule of any one of embodiments 1 to 3, wherein the powder composition is 2 to 8 weight percent of the granule. Embodiment 5 is the fertilizer granule of any one of embodiments 1 to 4, wherein the urease inhibitor is N- (N-butyl) thiophosphoric triamide (NBTPT) and the nitrification inhibitor is dicyandiamide (DCD). Embodiment 6 is the fertilizer granule of any one of embodiments 1 to 5,wherein the filler comprises one or more of silica, distillers dried grains with solubles (DDGS), kaolin, bentonite, rice bran, plaster of paris, flour, biodegradable bleached wheat flour, starch, or gluten. Embodiment 7 is the fertilizer granule of any one of embodiments 1 to 6, wherein the powder composition further comprises a pH buffer comprising chalk powder, CaCO₃、MgO、KH₂PO₄、NaHCO₃、Na₂CO₃、K₂CO₃Or MgCO₃One or more than one. Embodiment 8 is the fertilizer granule of any one of embodiments 1 to 7, wherein the granule is substantially homogeneous. Embodiment 9 is the fertilizer granule of any one of embodiments 1 to 8, wherein the granule has a diameter of about 2mm to 4 mm. Embodiment 10 is the fertilizer granule of any one of embodiments 1 to 9, wherein the granule contains 2 wt% to 8 wt% filler, 0.05 wt% to 0.11 wt% NBTPT, 0.5 wt% to 2 wt% DCD, 2 wt% to 8 wt% pH buffer, and 92 wt% to 98 wt% urea. Embodiment 11 is the fertilizer granule of any one of embodiments 1 to 10, wherein less than 20 wt% of the nitrogen in the fertilizer granule is lost via ammonia volatilization after exposure to greenville soil for 20 days. Embodiment 12 is the fertilizer granule of any one of embodiments 1 to 11, wherein the fertilizer granule retains at least 90% of the urease inhibitor after storage of the granule in a closed container at 22 ℃ for 30 days. Embodiment 13 is the fertilizer granule of any one of embodiments 1 to 12, comprising NBTPT and n-butylamine, wherein the weight ratio of NBTPT to n-butylamine is about 30:1 to 15: 1. Embodiment 14 is a fertilizer granule comprising a powder composition distributed throughout a solid urea matrix, wherein the powder composition comprises a filler and NBTPT, and wherein NBTPT is less than 5 wt% of the powder composition. Embodiment 15 is a method of preparing a granular fertilizer composition comprising: a) providing a powder composition comprising a powdered filler and at least one of powdered N- (N-butyl) thiophosphoric triamide (NBTPT) or powdered dicyandiamide (DCD); b) under conditions sufficient to form a plurality of solid particles comprising the powder composition and solid ureaNext, the powder composition is contacted with a composition comprising molten urea. Embodiment 16 is the method of embodiment 15, wherein step (b) comprises spraying the composition comprising molten urea onto the powder composition while agitating the powder composition in a granulation device. Embodiment 17 is the method of embodiment 15 or 16, wherein the powder composition comprises no more than 5 wt% NBTPT or no more than 30 wt% DCD. Embodiment 18 is the method of any one of embodiments 15 to 17, wherein after step (b), the powder composition is distributed throughout the solid particles. Embodiment 19 is the method of any one of embodiments 15 to 18, wherein the powder composition further comprises a pH buffer comprising chalk powder, CaCO₃、MgO、KH₂PO₄、NaHCO₃、Na₂CO₃、K₂CO₃Or MgCO₃One or more than one. Embodiment 20 is the method of any one of embodiments 15 to 19, wherein the solid particles comprise 2 to 8 wt% filler, 0.05 to 0.11 wt% NBTPT, 0.5 to 2 wt% DCD, 2 to 8 wt% pH buffer, and 92 to 98 wt% urea.

The term "about" or "approximately" is defined as being close as understood by one of ordinary skill in the art. In one non-limiting embodiment, the term is defined as within 10%, preferably within 5%, more preferably within 1%, and most preferably within 0.5%.

The terms "weight percent" or "volume percent" refer to the weight percent of a component or the volume percent of a component, respectively, based on the total weight of the material comprising the component or the total volume of the material. In one non-limiting example, 10 grams of a component in a total of 100 grams of material, including 10 grams of a component, is 10 weight percent of the component.

The term "substantially" is defined as including ranges within 10%, within 5%, within 1%, or within 0.5%.

The terms "inhibit" or "reduce" or "prevent" or "avoid" when used in the claims and/or the specification includes any measurable reduction or complete inhibition to achieve a desired result.

As used in this specification and/or in the claims, the term "effective" means suitable for achieving a desired, expected, or expected result.

When used in conjunction with any of the terms "comprising," including, "" containing, "or" having "in the claims or specification, the singular forms" a, "" an, "and" the "are intended to mean" one "or" an "without the use of quantity prior to the element, but it is also intended to correspond to the meaning of" one or more, "" at least one, "and" one or more than one.

The words "comprising," "having," "including," or "containing" are inclusive or open-ended and do not exclude additional, unrecited elements or method steps.

The fertilizer compositions of the present invention may "comprise," "consist essentially of," or "consist of" the particular ingredients, components, compositions, etc. disclosed throughout this specification. With respect to the conjunction "consisting essentially of … …," in one non-limiting aspect, an essential and novel feature of the fertilizer granule compositions of the present invention is their ability to inhibit the degradation of the nitrogen stabilizer.

Other objects, features and advantages of the present invention will become apparent from the following drawings, detailed description and examples. It should be understood, however, that the drawings, detailed description, and examples, while indicating specific embodiments of the present invention, are given by way of illustration only, and are not intended to be limiting. In addition, it is contemplated that variations and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. In further embodiments, features from specific embodiments may be combined with features from other embodiments. For example, features from one embodiment may be combined with features of any other embodiment. In other embodiments, additional features may be added to the specific embodiments described herein.

Drawings

Advantages of the present invention will become apparent to those skilled in the art from the following detailed description, taken in conjunction with the accompanying drawings. While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings. The drawings may not be to scale.

Fig. 1 shows a cross-section of a fertilizer granule embodiment.

Fig. 2 depicts an embodiment of a method of producing a fertilizer granule.

Detailed Description

The fertilizer granules described herein comprise a nitrification inhibitor and/or a urease inhibitor in a powder composition distributed throughout a solid urea matrix. The powder composition may contain a filler material which provides protection against thermal degradation of the inhibitor during manufacture. These and other non-limiting aspects of the invention are discussed in further detail in the following sections.

A. Fertilizer granules

An exemplary cross-sectional view of an embodiment of a fertilizer granule is depicted in fig. 1A. In the embodiment shown, fertilizer granule 8 may comprise nitrogen stabilizer granule 2 and filler granule 4 embedded in solid urea matrix 6. The nitrogen stabilizer particles 2 and the filler particles 4 are part of a powder composition distributed within a solid urea matrix 6. The powder composition may also include a binder, pH balancing agent, or other suitable ingredient that affects the physical properties of the fertilizer granules 8 or makes the fertilizer granules 8 more effective in promoting plant growth. The filler particles 4 are present in the fertilizer granule 8 in a higher amount than the nitrogen stabiliser granule 2. The illustrations in fig. 1A and 1B are not intended to depict the shape or relative size of the nitrogen stabilizer particles 2 and the filler particles 4.

Fig. 1B shows an illustrative cross-sectional view of another embodiment of fertilizer granule 10. The difference between the shown fig. 1A and fig. 1B is that in the latter the solid urea matrix 6 has a portion 12, which portion 12 does not have a large amount of nitrogen stabilizer particles 2 or filler particles 4 embedded therein. Although the fertilizer granule 10 is depicted as having a relatively abrupt transition between the portion of the urea matrix 6 in which the powder composition is embedded and the portion 12 in which the powder composition is not embedded, in some embodiments, the transition may be a gradient.

In some embodiments, the powder composition may form discrete clusters or agglomerates of powder particles, including fillers and inhibitors, that are distributed within a solid urea matrix.

Although the fertilizer granules shown in fig. 1A and 1B have a circular cross-section, various shapes are possible. For example, the fertilizer granules may be spherical, disc-shaped, ovoid, or elliptical. The fertilizer granules may also be of various sizes. In some embodiments, the fertilizer granules have a longest dimension of about 1mm to 8 mm.

Fertilizer granules have desirable physical properties such as desirable levels of attrition resistance, granule strength, granulability, hygroscopicity, granule shape, and particle size distribution, which are important properties for fertilizer granules. Thus, the ingredients of the powder composition, such as fillers, pH balancing agents, binders, etc., may be selected to optimize these properties.

A particular application of the embodiments disclosed herein is the stabilization of inhibitors, such as the stabilization of NBTPT and/or DCD and other fertilizer additives present in fertilizer granules. Some fertilizer additives are unstable and are susceptible to degradation when exposed to high temperatures, pH changes (acidic or basic), and the like.

In conventional fertilizer technology, various fertilizer additives are mixed with the fertilizer using an "all in one" process. In these cases, the fertilizer, fertilizer additives, excipients, and other ingredients are mixed together to form the fertilizer composition in the form of granules or pellets. In most cases, granulation is carried out at elevated temperatures to bring the fertilizer composition into a molten state. For example, the granulation temperature of molten urea is about 135 ℃ at about 35 atmospheres. Under these conditions, many fertilizer additives at least partially degrade. Traditionally, these stability problems have been circumvented by using large excesses of fertilizer additives. Such processes, while in use, are not optimal and pose problems with respect to cost, efficacy, by-products, environmental waste, and greenhouse gases, among others.

The production methods disclosed herein provide a solution to the instability of fertilizer additives at high temperatures, where one or more than one fertilizer additive, including nitrogen stabilizers, may be included in a powder composition, which may include one or more than one filler, which may be defined in some embodiments as a thermal degradation inhibitor. The ingredients in the powder composition may be selected such that the resulting powder composition synergistically protects the fertilizer additive from high temperature degradation during the manufacturing process. This allows for the use of smaller amounts of additives in the manufacturing process.

Certain fertilizer additives are not stable to changes in pH during manufacture or after application to soil. For example, in the case of a nitrogen-containing fertilizer, the soil environment may become acidic after application, depending on the case. Thus, fertilizer additives that are sensitive to acidic pH degrade and will not be able to achieve their full performance. Including large excesses of fertilizer additives to compensate for losses due to pH changes may not be successful because large excesses of fertilizer (as compared to fertilizer additives) may continue to change the pH of the soil environment. Also, some commercial products, e.g.The fertilizer additive is added to the fertilizer composition using an organic solvent, such as NMP. Such use is undesirable and avoided in the production of certain embodiments of the fertilizer granules described herein.

B. Urease inhibitors and nitrification inhibitors

Urea is one of the most widely used fertilizers due to its high nitrogen content (46.6%). Various urease inhibitors and nitrification inhibitors have been developed to improve the efficiency of urea fertilizers, but their use can be challenging due to stability issues in the soil under various conditions (e.g., pH, temperature, precipitation, etc.). For example, NBTPT is known to be a good inhibitor of urease, but is unstable at acidic pH. NBTPT also decomposes when exposed to high temperatures, such as the temperature at which urea melts (about 135 ℃ to 140 ℃).

To overcome these problems, embodiments of fertilizer granules comprising a powder embedded within a solid urea matrix are providedThe powder composition, which may include a nitrogen stabilizer and a filler, is also defined as an antidegradant in some embodiments. In addition to fillers, the powder composition may also comprise binders, pH buffers and other fertilizer additives. pH buffers (e.g. CaCO)₃Available in the form of chalk powder) is a material that neutralizes the acidity caused by the hydrolysis of urea and thereby prevents degradation of the active agent (e.g., NBTPT) when placed in soil at acidic pH. Thus, the pH buffer may increase the efficacy of the active agent, such as NBTPT, and also maintain the pH of the soil.

The filler in the powder composition is also defined in some embodiments as an antidegradant, which is believed to protect the active ingredient (e.g., NBTPT) from exposure to high temperatures during granulation, thereby preventing decomposition of the NBTPT during granulation. For example, a plaster of Paris (PoP) -containing powder composition can effectively prevent NBTPT from degrading during granulation, thereby reducing the total amount of NBTPT that must be added during manufacture. In such formulations, the PoP protects all active ingredients in the powder composition.

Other inhibitors besides NBTPT and DCD may also be included in the fertilizer granules described herein, including but not limited to 3, 4-dimethylpyrazole phosphate (DMPP), Thiourea (TU), Phenyl Phosphorodiamidite (PPDA), 2-chloro-6- (trichloromethyl) -pyridine (triclopyr), 5-ethoxy-3-trichloromethyl-1, 2, 4-thiadiazole (cloxazole), 2-amino-4-chloro-6-methyl-pyrimidine (AM), 2-Mercaptobenzothiazole (MBT), or 2-Sulfoaminoimidazole (ST), or combinations thereof.

In addition to urea, other fertilizer materials may be included in the fertilizer granule. Other fertilizers may be selected based on the particular needs of certain types of soil, climate or other growing conditions to maximize the efficacy of the fertilizer granules in enhancing plant growth and crop yield. Other additives may also be included in the fertilizer granule including, but not limited to, micronutrients, primary nutrients, and secondary nutrients. Micronutrients are phytologically acceptable forms of inorganic or organometallic compounds such as boron, copper, iron, chloride, manganese, molybdenum, nickel or zinc. The primary nutrients are substances that can deliver nitrogen, phosphorus and/or potassium to plants. The primary nitrogen-containing nutrient may include urea, ammonium nitrate, ammonium sulfate, diammonium phosphate, monoammonium phosphate, urea formaldehyde, or a combination thereof. Secondary nutrients are substances that can deliver calcium, magnesium and/or sulfur to plants. The secondary nutrient may include lime, gypsum, calcium superphosphate, or a combination thereof. The other fertilizer materials described in this paragraph may be included in the powder composition during the manufacturing process, depending on whether it is necessary or desirable to protect the other materials from thermal degradation, or may be added to the molten urea prior to granulation.

C. Filler material

The fertilizer granules described herein comprise a filler, which in some embodiments is also defined as an antidegradant. Fillers may be selected based on their ability to protect certain fertilizer additives (e.g., nitrogen stabilizers) from thermal degradation during the manufacturing process. Fillers can also affect the physical properties of the fertilizer granule, such as crush strength and uniformity, and can alter the kinetics of release of nitrogen stabilizers or micronutrients from the fertilizer granule. The amount and type of filler may be selected based on the ability of the filler to prevent thermal degradation of the fertilizer additive and the desired final properties of the fertilizer granule.

In one aspect, the filler may comprise plaster of paris, flour, starch, gluten, kaolin, bentonite, or a combination thereof. Suitable flours may include, but are not limited to, rice flour, wheat flour, and bleached wheat flour. Suitable starches may include, but are not limited to, dextrin-modified starches. The filler may also comprise, for example, silica, distillers dried grains with solubles (DDGS), rice bran or other biological material, or combinations thereof.

In another aspect, the filler can comprise a phosphate, a polyphosphate, a biodegradable polymer, or a combination thereof. Suitable phosphates may include, but are not limited to, diammonium phosphate and monoammonium phosphate. Suitable polyphosphates may include, but are not limited to ammonium polyphosphate. Suitable biodegradable polymers may include, but are not limited to, polyacrylamide, polyacrylic acid, polyacrylonitrile, biodegradable polylactic acid, and other biodegradable polymeric materials, such as polylactic acid, poly (3-hydroxypropionic acid), polyvinyl alcohol, poly-epsilon-caprolactone, poly-L-lactide, polybutylene succinate, and biodegradable starch-based polymers.

pH buffers

The fertilizer granules may also contain one or more than one pH buffering agent to help counteract the tendency of the urea fertilizer to acidify the soil. Examples of suitable pH buffers include, but are not limited to, CaCO₃，MgO，KH₂PO₄，NaHCO₃Chalk, aluminium, magnesium hydroxide, aluminium hydroxide/magnesium hydroxide coprecipitates, aluminium hydroxide/sodium bicarbonate coprecipitates, calcium acetate, calcium bicarbonate, calcium borate, calcium carbonate, calcium bicarbonate, calcium citrate, calcium gluconate, calcium hydroxide, disodium hydrogen phosphate, dipotassium hydrogen phosphate, disodium hydrogen phosphate, magnesium acetate, magnesium borate, magnesium bicarbonate, magnesium carbonate, magnesium hydroxide, magnesium lactate, magnesium oxide, magnesium phosphate, magnesium silicate, magnesium succinate, magnesium tartrate, potassium acetate, potassium carbonate, potassium bicarbonate, potassium borate, potassium citrate, potassium metaphosphate, potassium phthalate, potassium phosphate, potassium polyphosphate, potassium pyrophosphate, potassium succinate, potassium tartrate, sodium acetate, sodium bicarbonate, sodium borate, sodium carbonate, sodium citrate, sodium gluconate, sodium hydrogen phosphate, sodium hydroxide, sodium lactate, sodium phthalate, sodium phosphate, sodium polyphosphate, sodium pyrophosphate, sodium tartrate, sodium tripolyphosphate, synthetic hydrotalcite, tetrapotassium pyrophosphate, tetrasodium pyrophosphate, tripotassium phosphate, trisodium phosphate and butanetriol, and combinations thereof. If a pH buffering agent is used, it may be part of the powder composition of the invention, or it may be added and mixed into the molten urea prior to granulation.

F. Matrix composition

In one aspect, the powder composition is distributed throughout a matrix that may comprise primarily urea. The urea base may also comprise one or more than one other nitrogen fertilizer. Suitable other nitrogen fertilizers may include, but are not limited to, ammonium nitrate, ammonium sulfate, DAP, MAP, urea formaldehyde, ammonium chloride, and potassium nitrate.

G. Composition comprising a metal oxide and a metal oxide

The fertilizer granules described herein may be included in a composition for application to soil. In addition to the fertilizer granules, the composition may include other fertilizer compounds, micronutrients, primary nutrients, secondary nutrients, pesticides, herbicides, fungicides, and combinations thereof.

The fertilizer granules described herein may also be included in a blend composition that may contain other fertilizer granules. Other fertilizer granules may be granules of urea, mono super phosphate (SSP), Tri Super Phosphate (TSP), ammonium sulphate, etc.

H. Method for producing fertilizer granules

The methods of manufacturing the fertilizer granules described herein generally include preparing a powder composition that may include at least a nitrogen stabilizer and a filler, and then contacting the powder composition with a molten urea composition under conditions sufficient to form a plurality of solid particles that may include the powder composition embedded in a solid urea matrix. In some embodiments, the contacting step can be performed in a granulation apparatus. In such an embodiment, the powder composition may be added to the granulation apparatus and then the molten urea composition may be sprayed onto the powder composition while the powder composition is in motion. This process may also be referred to as "fattening" the powder composition. When the molten urea-comprising composition is sprayed onto the powder composition, it cools and solidifies, resulting in fertilizer granules with the powder composition embedded in a solid urea matrix. The resulting fertilizer granules can be of various sizes. In some embodiments, the fertilizer granule has a size of about 1mm to 8 mm. In some other embodiments, molten urea may be added to the powder composition. In these embodiments, as the molten urea cools and solidifies, it provides the fertilizer granules with a powder composition embedded in a urea matrix.

The powder composition may be formed by mixing the nitrogen stabilizer powder with the filler powder and any other dry ingredients. This can be done before the powder composition is fed into the granulation apparatus. In addition, mixing may be performed in the granulation equipment before the fattening process begins.

Fig. 2 shows an embodiment of a method by which fertilizer granules 8 can be produced. The powder composition, which may comprise nitrogen stabilizer granules 2 and filler granules 4, is placed in a granulator 14, which is opened to move the powder composition. The molten urea, which may also include additional additives, is then fed to the granulator 14 through a pipe 16. Within the granulator 14, the molten urea is sprayed onto the powder composition where it is cooled and solidified, a process known as fattening 18. After fattening 18, the nitrogen stabilizer 2 and the filler 4 are embedded in the fertilizer granules 8.

During the manufacturing process of the fertilizer granules, the fattening process "consumes" the powder composition: as the molten urea is sprayed onto the agitated powder composition, the powder composition is incorporated into the growing fertilizer granules. After the powder composition is completely incorporated into the fertilizer granules, the fattening process may continue for a period of time, in which case the additional solid urea will not contain a significant amount of the powder composition. This process will produce a fertilizer granule similar to that shown in fig. 1B, where the urea matrix 6 has a portion 12, which portion 12 is substantially free of nitrogen stabilizer particles 2 and filler particles 4. On the other hand, if fattening is stopped at about the same time that all of the powder composition is incorporated into the fertilizer granule, the fertilizer granule will be more similar to the fertilizer granule shown in fig. 1A, wherein the nitrogen stabilizer particles 2 and filler particles 4 are distributed throughout substantially all of the fertilizer granule 8. In some embodiments, there will be a gradient where the portion of the solid urea matrix 6 near the outside of the particle has a lower concentration of nitrogen stabilizer particles 2 and filler particles 4 than the portion near the center.

The powder composition may be characterized by the size of the powder particles therein. In some embodiments, the powder particles have an average size of less than about 50 μm, 100 μm, 150 μm, or 200 μm. In some embodiments, the powder particles are about 10 μm to 200 μm in size. In some embodiments, the powder does not include any particles having a size greater than about 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, or 600 μm, or does not include a plurality of particles having a size greater than those values.

I. Application method of fertilizer granules

The fertilizer granules described herein are useful in methods of increasing the amount of nitrogen in soil and enhancing plant growth. Such methods may include applying to the soil an effective amount of a composition that may include fertilizer particles. The method may include increasing the growth and yield of crops such as rice, wheat, corn, barley, oats, and soybean.

The effectiveness of the compositions described herein, which may contain fertilizer particles, can be determined by measuring the nitrogen content of the soil at various times after the fertilizer composition is applied to the soil. It is understood that different soils have different characteristics which affect the stability of nitrogen in the soil. The effectiveness of the fertilizer composition can also be directly compared to other fertilizer compositions by side-by-side comparison in the same soil under the same conditions. Compositions comprising fertilizer particles as described herein may be directly mixed with, for exampleOr

Compare with the fertilizer.

Sold by KochFertilizer, LLC, is a liquid formulation containing NBTPT, with NMP as the main solvent along with other additives, which is typically dispensed onto urea granules at the farm site. Therefore, it requires an additional step and incorporates NMP, a toxic solvent, before it can be used by farmers. A huge odor occurs during use.

Marketed by KochFertilizer, LLC, is a urea formulation containing NBTPT and DCD prepared by adding both inhibitors to the urea melt during granulation.