Urea-based blend composition and method for the manufacture thereof

Abstract

The invention relates to a solid, particulate, urea-based blend composition comprising a urea-based compound in particulate form, one or more components in particulate form, selected from the group of nitrates, phosphates, sulphates and chlorides, and a urease inhibitor of the type phosphoric triamide, in particular N-(n-butyl) thiophosphoric triamide (nBTPT), wherein the urea-based blend composition is further characterized in that it comprises one or more reactive alkaline or alkaline-forming inorganic or organic compounds. The composition according to the invention has been stabilized against the degradation of a urease inhibitor of the type phosphoric triamide, in particular N-(n-butyl) thiophosphoric triamide (nBTPT). The invention further relates to a method for the manufacture of the claimed solid, particulate, urea-based blend composition.

Claims

1. A solid, particulate, urea-based physical blend composition comprising a urea-based compound in particulate form, one or more components in particulate form, selected from the group of nitrates, phosphates, sulphates and chlorides, and a urease inhibitor of the type phosphoric triamide, wherein the urea-based physical blend composition is further characterized in that it comprises 0.0001 to 1 weight %, relative to the total weight of the composition, of one or more reactive alkaline or alkaline-forming inorganic or organic compounds, wherein the one or more reactive alkaline or alkaline-forming inorganic or organic compounds is able to interact with said one or more components selected from the group of nitrates, phosphates, sulphates and chlorides, with the proviso that the alkaline-forming compound is not an organic alkaline solvent, used as inert carrier for the urease inhibitor of the type phosphoric triamide.

2. The urea-based physical blend composition according to claim 1, characterized in that the average particle size (dp50) of the urea-based compound in particulate form and the one or more components in particulate form, selected from the group of nitrates, phosphates, sulphates and chlorides is between 1.0 mm and 5 cm, as determined by mesh sieve screening.

3. The urea-based physical blend composition according to claim 1, characterized in that it further comprises an anti-caking coating, a moisture repellent coating, an anti-dust coating, or combinations thereof.

4. The urea-based physical blend composition according to claim 1, characterized in that the urease inhibitor of the type phosphoric triamide is a compound of formula: ##STR00004## wherein: X is oxygen or sulphur; R.sub.1 is alkyl, cycloalkenyl, aralkyl, aryl, alkenyl, alkynyl, or cycloalkyl; R.sub.2 is hydrogen, alkyl, cycloalkenyl, aralkyl, aryl, alkenyl, alkynyl, or cycloalkyl; or R.sub.1 and R.sub.2 together may form an alkylene or alkenylene chain which may optionally include one or more heteroatoms of divalent oxygen, nitrogen or sulphur completing a 4, 5, 6, 7, or 8 membered ring system; and R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are individually hydrogen or alkyl having 1 to 6 carbon atoms.

5. The urea-based physical blend composition according to claim 1, wherein the urease inhibitor is N-(n-butyl) thiophosphoric triamide (nBTPT).

6. The urea-based physical blend composition according to claim 1, wherein the urease inhibitor is present at a level of 0.0001 to 1% weight %, relative to the total weight of the urea-based physical blend composition.

7. The urea-based physical blend composition according to claim 1, wherein the urease inhibitor is applied onto the urea-based compound in liquid or in particulate form, is melt-mixed with the urea-based compound, or a combination thereof.

8. The urea-based physical blend composition according to claim 1, wherein the reactive alkaline-forming or alkaline inorganic or organic compound is selected from the group of metal oxides, carbonates, hydroxides, acetates, and organic bases, and any mixture thereof.

9. The urea-based physical blend composition according to claim 8, wherein the reactive alkaline-forming or alkaline compound is selected from the group of calcium oxide, zinc oxide, magnesium oxide, calcium carbonate, and any mixture thereof.

10. The urea-based physical blend composition according to claim 1, wherein the reactive alkaline-forming or alkaline compound is present in the composition at a level of 0.02 to 1 weight %, relative to the total weight of the composition.

11. The urea-based physical blend composition according to claim 1, wherein the weight ratio of urease inhibitor of the type phosphoric triamide to one or more reactive alkaline or alkaline-forming inorganic compounds ranges from 1:20 to 1:1.

12. The urea-based physical blend composition according to claim 1, further comprising an anti-caking coating, a moisture repellent coating, an anti-dust coating, or combinations thereof, applied onto the particulate components of the urea-based physical blend composition, wherein the coating comprises at least a non-polar material present in the composition at a level of 0.0001 to 1 weight %, relative to the total weight of the composition.

13. The urea-based physical blend composition according to claim 1, wherein the urea-based physical blend composition is packaged without the presence of a head space.

14. The urea-based physical blend composition according to claim 1, wherein the urea-based compound is selected from the group of urea, urea calcium sulphate (UCaS), urea calcium nitrate (UCaN), urea magnesium nitrate (UMgN), urea calcium phosphate (UCaP), urea magnesium phosphate (UMgP), urea superphosphate (USP), urea calcium ammonium nitrate (UCAN), urea ammonium sulphate (UAS), urea ammonium phosphate (UAP), urea potassium salts (UK), or mixtures thereof.

15. The urea-based physical blend composition according to claim 1, wherein the one or more components in particulate form, selected from the group of nitrates, phosphates, sulphates and chlorides is selected from the group of: ammonium nitrate, calcium nitrate, calcium ammonium nitrate, sodium nitrate, ammonium sulphate nitrate, potassium ammonium nitrate, ammonium phosphate, calcium bis(dihydrogen orthophosphate), super phosphate, triple superphosphate, rock phosphate, potassium sulphate, potassium magnesium sulphate, ammonium sulphate (AS), urea ammonium sulphate, urea calcium ammonium nitrate, urea ammonium sulphate, potassium chloride (MOP), urea potassium salts (UK), or mixtures thereof.

16. The urea-based physical blend composition according to claim 1, wherein the composition contains from about 0.1 to 60 weight % of one or more components in particulate form, selected from the group of nitrates, phosphates, sulphates and chlorides.

17. The urea-based physical blend composition according to claim 1, wherein the composition contains: 40 to 99 weight % of a urea-based compound in particulate form; 0.1 to 60 weight % of one or more components in particulate form, selected from the group of nitrates, phosphates, sulphates and chlorides; 0.0001 to 1 weight % of a urease inhibitor of the type phosphoric triamide; 0.0001 to 1 weight % of one or more reactive alkaline or alkaline-forming inorganic or organic compounds; and 0 to 1 weight % of an anti-caking coating, a moisture repellent coating, an anti-dust coating, or combinations thereof, adding up to 100 weight %, being the total weight of the composition.

18. The urea-based physical blend composition according to claim 1, comprising urea in particulate form either coated or melt-mixed with a urease inhibitor of the type phosphoric triamide, ammonium phosphate (MAP or DAP) in particulate form, potassium chloride (MOP), and magnesium oxide.

19. The urea-based physical blend composition according to claim 1, comprising urea in particulate form either coated or melt-mixed with a urease inhibitor of the type phosphoric triamide, ammonium sulphate (AS) in particulate form, and magnesium oxide.

20. The urea-based physical blend composition according to claim 1, wherein the urease inhibitor is present at a level of 0.002 to 0.2 weight %, relative to the total weight of the urea-based physical blend composition.

21. The urea-based physical blend composition according to claim 1, wherein the urease inhibitor is present at a level of 0.04 to 0.06 weight %, relative to the total weight of the urea-based physical blend composition.

22. The urea-based physical blend composition according to claim 1, wherein the reactive alkaline-forming or alkaline compound is present in the composition at a level of 0.05 to 1 weight %, relative to the total weight of the composition.

23. The urea-based physical blend composition according to claim 1, wherein the weight ratio of urease inhibitor of the type phosphoric triamide to one or more reactive alkaline or alkaline-forming inorganic compounds ranges from 1:15 to 1:1.

24. The urea-based physical blend composition according to claim 1, wherein the weight ratio of urease inhibitor of the type phosphoric triamide to one or more reactive alkaline or alkaline-forming inorganic compounds ranges from 1:10 to 1:1.

25. A fertilizer, in particular for supporting the growth of agricultural products on a sulphur-deficient soil, a phosphor-deficient soil, a potassium-deficient soil, or combinations thereof, comprising the urea-based physical blend composition according to claim 1.

26. An animal feed comprising the urea-based physical blend composition according to claim 1.

27. A method for the manufacture of a solid, particulate, urea-based physical blend composition according to claim 1, the method comprising the steps of: 1) providing a urea-based particulate material which is treated with a urease inhibitor of the type phosphoric triamide in solid particulate or liquid form; 2) providing a particulate material, comprising one or more components selected from the group of nitrates, phosphates, sulphates and chlorides; 3) providing 0.0001 to 1 weight %, relative to the total weight of the composition, of one or more reactive alkaline or alkaline-forming inorganic or organic compounds that is able to interact with the one or more components selected from the group of nitrates, phosphates, sulphates and chlorides, with the proviso that the alkaline-forming compound is not an organic alkaline solvent, used as inert carrier for the urease inhibitor of the type phosphoric triamide; and 4) mixing the components provided in steps 1), 2), and 3); and 5) optionally, applying a coating to one or more of the particulate compounds, wherein the coating that is able to increase at least the anticaking property, water repellence property, anti-dust property, or a combination thereof, of said urea-based physical blend composition.

28. Method for improving the stability of a urease inhibitor of the type phosphoric triamide in a solid, particulate, urea-based physical blend composition comprising a urea-based compound in particulate form, one or more components in particulate form, selected from the group of nitrates, phosphates, sulphates and chlorides and said urease inhibitor, comprising the steps of: a) addition to the composition of 0.0001 to 1 weight %, relative to the total weight of the composition, of one or more reactive alkaline or alkaline-forming inorganic or organic compounds, that is able to interact with the one or more components selected from the group of nitrates, phosphates, sulphates and chlorides, with the proviso that the alkaline-forming compound is not an organic alkaline solvent, used as inert carrier for the urease inhibitor of the type phosphoric triamide; and b) optionally, application of an anticaking and/or moisture repellent coating onto said urea-based physical blend composition.

Description

EXAMPLES

Description of Figures

(1) FIG. 1: Stability of different liquid nBTPT-formulations applied in and on granular urea with or without blending with granular AS (1:1 ratio urea:AS)-% recovery of nBTPT after 35 days of storage open to air in jars in nissenhut (day/night cycle 16-42° C./27-77% relative humidity). [A=Agrotain® Ultra in urea, B=Agrotain® Ultra on urea, C=N Yield™ in urea, C=N Yield™ on urea].

(2) FIG. 2: Stability of solid nBTPT applied in and on urea (500 ppm nBTPT addition) with or without blending with DAP (1:1 ratio urea:DAP)-% recovery of nBTPT after 35 days of storage open to air in jars in nissenhut (day/night cycle 16-42° C./27-77 relative humidity). [A=nBTPT powder in urea, B=nBTPT powder on urea].

(3) FIG. 3: Stability of solid nBTPT applied in and on urea (500 ppm nBTPT addition) with or without blending with KCl (1:1 ratio urea:KCl)-% recovery of nBTPT after 35 days of storage open to air in jars in nissenhut (day/night cycle 16-42° C./27-77% relative humidity). [A=nBTPT powder in urea, B=nBTPT powder on urea].

(4) FIG. 4: Stability of different nBTPT-formulations (500 ppm nBTPT addition) applied in and on urea with or without blending with DAP and KCl (Triple 19 ratio)-% recovery of nBTPT after 35 days of storage open to air in jars in nissenhut (day/night cycle 16-42° C./27-77% relative humidity). [A=nBTPT powder in urea, B=nBTPT powder on urea, C=Agrotain® Ultra (liquid) in urea, D=Agrotain® Ultra (liquid) on urea].

(5) FIG. 5. Stability of nBTPT in and on urea with or without blending with granular AS: effect of the addition of CaO-% recovery of nBTPT after 14 days of open to air storage in jars at nissenhut (day/night cycle 16-42° C./27-77% relative humidity). A=[500 ppm nBTPT powder in urea]+AS 1:1 B=[500 ppm nBTPT powder in urea+2650 ppm CaO]+AS 1:1 C=[500 ppm nBTPT powder on urea]+AS 1:1 D=[500 ppm nBTPT powder on urea+2650 ppm CaO]+AS 1:1

(6) FIG. 6: Stability of nBTPT in and on urea with or without blending with DAP and KCl (Triple 19 ratio): effect of the addition of CaO-% recovery of nBTPT after 14 days of open to air storage in jars at nissenhut (day/night cycle 16-42° C./27-77% relative humidity). A=[500 ppm nBTPT powder in urea]+DAP/KCl triple 19 B=[500 ppm nBTPT powder in urea+2650 ppm CaO]+DAP/KCl triple 19 C=[500 ppm nBTPT powder on urea]+DAP/KCl triple 19 D=[500 ppm nBTPT powder on urea+2650 ppm CaO]+DAP/KCl triple 19

(7) FIG. 7: Stability of nBTPT on urea blended with DAP in 1:1 (weight/weight) ratio: effect of the addition of CaO, MgO, ZnO, CaCO.sub.3, triethylamine and diethanolamine-% recovery of nBTPT after 14 days of bagged storage at 20° C. A=[900 ppm nBTPT as Agrotain® Ultra on urea]+DAP 1:1 ratio B=[900 ppm nBTPT as Agrotain® Ultra on urea+2500 ppm CaO]+DAP 1:1 ratio C=[900 ppm nBTPT as Agrotain® Ultra on urea+2500 ppm MgO]+DAP 1:1 ratio D=[900 ppm nBTPT as Agrotain® Ultra on urea+2500 ppm ZnO]+DAP 1:1 ratio E=[900 ppm nBTPT as Agrotain® Ultra on urea+2500 ppm CaCO.sub.3]+DAP 1:1 ratio F=[900 ppm nBTPT as Agrotain® Ultra on urea+2500 ppm triethylamine]+DAP 1:1 ratio G=[900 ppm nBTPT as Agrotain® Ultra on urea+2500 ppm diethanolamine]+DAP 1:1 ratio

(8) FIG. 8. Stability of different nBTPT formulations (500 ppm) in and on urea in a blend with granular AS: bagged versus open to air storage-% recovery of nBTPT after 35 days of storage in nissenhut (day/night cycle 16-42° C./27-77% relative humidity). A=[500 ppm nBTPT powder in urea]+AS 1:1 B=[500 ppm nBTPT powder on urea]+AS 1:1 C=[500 ppm nBTPT as Agrotain® Ultra in urea]+AS 1:1 D=[500 ppm nBTPT as Agrotain® Ultra on urea]+AS 1:1

(9) FIG. 9: Stability of nBTPT on urea blended with DAP in 1:1 (weight/weight) ratio: effect of the addition of moisture repellent coating-% recovery of nBTPT after 14 days of bagged storage at 20° C. A=[900 ppm nBTPT as Agrotain® Ultra on urea]+DAP 1:1 ratio. B=[900 ppm nBTPT as Agrotain® Ultra on urea+3000 ppm NH coating]+DAP 1:1 ratio

EXPERIMENTAL

(10) 1. nBTPT Experiments

(11) nBTPT was mixed in urea in the following way: nBTPT was added to urea melt and subsequently this mixture was granulated in a fluidized bed granulator.

(12) For lab scale experiments, nBTPT was applied onto urea by adding 1.2 kg of urea-based compound to a lab scale drum. In a next step, the nBTPT material was slowly added. A residence time of 10 minutes was applied and the rotating speed of the drum was consequently the same in each experiment. In case a moisture repellent coating was added, a nebulizer was used and depending on the order of addition, the moisture repellent coating was added before or after addition of the nBTPT material. Before use, the moisture repellent coating was preheated to 80° C. Larger scale experiments with amounts up to 40 kg of fertilizer material were performed in a concrete mixer.

(13) In a next step, one or more reactive alkaline or alkaline-forming inorganic or organic compounds that is able to interact with the one or more components selected from the group of nitrates, phosphates, sulphates and chlorides was added;

(14) In a next step, a particulate material, comprising one or more components selected from the group of nitrates, phosphates, sulphates and chlorides was added;

(15) All the components were mixed thoroughly.

(16) Optionally, a coating to one or more of the particulate components that is able to increase at least the anti-caking and/or water repellent properties of said urea-based blend composition was added. Importantly, all the steps can be interchanged or the steps can be performed simultaneously.

(17) The samples were stored under several conditions, dependent on the type of samples: 20° C. closed plastic container with head space (Climate chamber, 80% relative humidity) Bagged at room temperature (20-25° C.) or in nissenhut (an unconditioned bulk hall) Open to air in nissenhut Cylinder test in nissenhut Open pile in nissenhut

(18) For some samples, an accelerated stability test was done storing these samples at elevated temperatures: Oven of 30° C. closed plastic container Oven of 30° C. open to air 30° C./60% RH open to air 70° C. closed plastic container

(19) Typically, a day/night cycle is generated in the nissenhut, with temperature fluctuations between 0 to 42° C. and fluctuations of relative humidity between 20 and 90%, which can be compared with real life storage in silos.

(20) 2. HPLC Analysis of nBTPT-Content

(21) HPLC analysis of nBTPT is done as described in the procedure CEN 15688-2007.

(22) In practice, the urea-based compound treated with nBTPT was picked and separated manually from the particulate material, comprising one or more components selected from the group of nitrates, phosphates, sulphates and chlorides, and then subsequently dissolved in water for HPLC analysis.

(23) 3. Products

(24) Solid N-(n-butyl)thiophosphoric triamide was obtained from Sunfit Chemical Co. (China) (CAS-Nr. 94317-64-3), as a white crystalline solid with a melting point of 58-60° C.

(25) DAP (NP 18-46-0, 90% 2-4 mm) was obtained from Triferto

(26) KCl was obtained from K+S Kali GmbH.

(27) AS was obtained from OCl (granular 2 mm and 3 mm grade)

(28) Coating: Moisture repellent (MR) coating was made according to EP 0768993 A1 (Norsk Hydro ASA) by mixing about 28 weight % of wax, about 68 weight % of oil and about 4 weight % of a resin, applied in an amount of about 0.1-0.5% weight % to the fertilizer. It will be referred herein as NH coating.

Example 1: Definition of the Problem

(29) FIG. 1 shows the stability of different commercially available liquid nBTPT-formulations, applied in and on urea with (left bar) or without (right bar) blending with granular ammonium sulphate (AS) (500 ppm nBTPT addition). The % recovery of nBTPT after 35 days of storage open to air in jars in nissenhut (day/night cycle 16-42° C./27-77% relative humidity) is shown. FIG. 3 shows clearly that, in contrast to urea, treated with nBTPT and not blended with AS, nBTPT degrades very fast when the urea, treated with nBTPT, is blended with granular AS.

(30) FIG. 2 shows the stability of solid nBTPT (500 ppm nBTPT addition) applied in and on urea with (left bar) or without (right bar) blending with di-ammonium phosphate (DAP). The % recovery of nBTPT after 35 days of storage open to air in jars in nissenhut (day/night cycle 16-42° C./27-77 relative humidity) is shown. FIG. 1 shows clearly that, in contrast to urea, treated with nBTPT and not blended with DAP, nBTPT in said compositions degrades very fast when the urea, treated with nBTPT, is blended with DAP in a 1:1 ratio. The degradation of nBTPT that is present in urea, is somewhat lower than when applied onto urea, but in the presence of DAP, the stability is drastically reduced in both cases.

(31) FIG. 3 shows the stability of solid nBTPT (500 ppm nBTPT addition) applied in and on urea with (left bar) or without (right bar) blending with KCl. The % recovery of nBTPT after 35 days of storage open to air in jars in nissenhut (day/night cycle 16-42° C./27-77% relative humidity) is shown. FIG. 1 shows clearly that, in contrast to urea, treated with nBTPT and not blended with KCl, nBTPT in said compositions degrades very fast when the urea, treated with nBTPT, is blended with DAP in a 1:1 ratio. The degradation of nBTPT that is present in urea, is somewhat lower than when applied onto urea, but in the presence of DAP, the stability is drastically reduced in both cases.

(32) FIG. 4 shows the stability of different nBTPT-formulations (500 ppm nBTPT addition) applied in and on urea with (left bar) or without (right bar) blending with DAP and KCl (Triple 19 ratio). The % recovery of nBTPT after 35 days of storage open to air in jars in nissenhut (day/night cycle 16-42° C./27-77% relative humidity) is shown. FIG. 3 shows clearly that, in contrast to urea treated with nBTPT and not blended with DAP and KCl, nBTPT degrades very dramatically when urea, treated with nBTPT, is blended with DAP and KCl in a triple 19 ratio.

Example 2: Effect of CaO on Urea/AS-Blend

(33) This example shows the beneficial effect of the addition of a reactive alkaline or alkaline-forming inorganic or organic compound on the stability of nBTPT in and on urea when blended with AS.

(34) FIG. 5 shows the stability of nBTPT in and on urea with or without blending with granular AS and the effect of the addition of CaO. The recovery of nBTPT after 14 days of open to air storage in jars at nissenhut (day/night cycle 16-42° C./27-77% relative humidity) is shown. The figure clearly shows the beneficial effect of the addition of CaO on the stability of nBTPT in or on urea blended with granular AS.

Example 3: Effect of Alkaline or Alkaline-Forming Inorganic or Organic Compound on Urea/DAP/KCl-Blend (NPK)

(35) This example shows the beneficial effect of the addition of a reactive alkaline or alkaline-forming inorganic or organic compound on the stability of nBTPT in and on urea when blended with DAP and KCl in triple 19 ratio (NPK 19:19:19) or blended with DAP in a 1:1 (weight/weight) ratio.

(36) FIG. 6 shows the stability of nBTPT in and on urea with or without blending with DAP and KCl and the effect of the addition of CaO. The recovery of nBTPT after 14 days of open to air storage in jars at nissenhut (day/night cycle 16-42° C./27-77% relative humidity) is shown. The figure clearly shows the beneficial effect of the addition of CaO on the stability of nBTPT in or on urea blended with DAP and KCl.

(37) FIG. 7 shows the stability of nBTPT on urea with or without blending with DAP in a 1:1 (weight/weight) ratio and the effect of the addition of alkaline inorganic compounds CaO, MgO, ZnO and CaCO.sub.3 and alkaline organic compounds triethylamine and diethanolamine. The recovery of nBTPT (in %) after 14 days of bagged storage at 20° C. is shown. The figure clearly shows the beneficial effect of the addition of these alkaline inorganic and organic compounds on the stability of nBTPT on urea blended with DAP in a 1:1 (weight/weight) ratio.

Example 4: Storage in Bags Versus Open to Air Storage

(38) This example shows the beneficial effect of the storage in bags without head space versus storage open to air on the stability of nBTPT in and on urea:AS 1:1 (weight:weight) blends.

(39) FIG. 8 shows the stability of different nBTPT formulations (500 ppm) in and on urea in a blend with granular AS when stored under bagged conditions versus open to air storage in jars. The graphs shows clearly the beneficial effect of bagged storage of the urea:AS blend on the stability of nBTPT in/on urea in contrast when storage was done open to air.

Example 5: Effect of the Addition of a Coating on Urea/DAP-Blend

(40) This example shows the beneficial effect of the addition of a moisture repellent coating on urea on the stability of nBTPT on urea:DAP 1:1 (weight:weight) blends.

(41) FIG. 9 shows the stability of nBTPT on urea in a blend with DAP in a 1:1 (weight/weight) ratio and the effect of the addition of a moisture repellent coating on [urea+nBTPT]. The recovery of nBTPT after 14 days of storage in bags at 20° C. is presented. The graph shows a small stabilizing effect of the addition of NH coating on the stability of nBTPT. No NH coating: 18.6% recovery of nBTPT With NH coating: 25.4% recovery of nBTPT