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DE-102024210784-A1 - Additive for the production of stabilized urea particles and its use

DE102024210784A1DE 102024210784 A1DE102024210784 A1DE 102024210784A1DE-102024210784-A1

Abstract

The invention relates to a particulate composition comprising, or substantially consisting of, urea, an inhibitor, preferably a urease inhibitor and/or a nitrification inhibitor, and an additive, wherein the additive comprises components (i) and (ii): (i) a carboxylic acid or an anhydride, salt, or derivative thereof; preferably a carboxylic acid salt or a carboxylic acid derivative, more preferably a carboxylic acid salt; and (ii) a polar polymer; preferably a water-soluble polar polymer. The invention further relates to a process for preparing the particulate composition, an additive for a particulate composition, and the use of the particulate composition as a fertilizer.

Inventors

  • Morten Dittmar
  • Rolf Weiss

Assignees

  • THYSSENKRUPP AG
  • THYSSENKRUPP UHDE FERTILIZER TECHNOLOGY GMBH

Dates

Publication Date
20260513
Application Date
20241108

Claims (20)

  1. Particle-shaped composition comprising or substantially consisting of urea, an inhibitor, preferably a urease inhibitor and/or a nitrification inhibitor, and an additive, wherein the additive comprises components (i) and (ii): (i) a carboxylic acid salt or a carboxylic acid derivative, preferably a carboxylic acid salt; and (ii) a polar polymer; preferably a water-soluble polar polymer.
  2. The particulate composition according to Claim 1 , wherein the urea content is at least 50 wt.%; preferably at least 60 wt.%, more preferably at least 70 wt.%, even more preferably at least 80 wt.%, most preferably at least 90 wt.%, and in particular at least 95 wt.%; in each case relative to the total weight of the particulate composition.
  3. The particulate composition according to Claim 1 or 2 , comprising a urease inhibitor; preferably a thiophosphoric triamide; preferably N-(n-butyl)thiophosphoric triamide (NBPT) and/or N-(n-propyl)thiophosphoric triamide (NPPT).
  4. The particulate composition according to any of the preceding claims, wherein the carboxylic acid salt or the carboxylic acid derivative is a salt or a derivative of a carboxylic acid having two or more carboxyl groups; preferably wherein the carboxylic acid salt or the carboxylic acid derivative is a salt or a derivative of a dicarboxylic acid or a tricarboxylic acid; more preferably an aliphatic dicarboxylic acid or tricarboxylic acid; even more preferably an aliphatic saturated dicarboxylic acid or tricarboxylic acid; and in particular an aliphatic saturated acyclic dicarboxylic acid or tricarboxylic acid.
  5. The particulate composition according to one of the preceding claims, wherein the carboxylic acid derivative is selected from the group consisting of carboxylic acid esters, carboxylic acid amides, and carboxylic acid imides.
  6. The particulate composition according to any of the preceding claims, wherein the carboxylic acid salt is calcium citrate, magnesium citrate, sodium citrate or potassium citrate; tricalcium dicitrate, trimagnesium dicitrate, trisodium citrate or tripotassium citrate; preferably trisodium citrate or tripotassium citrate; particularly preferably tripotassium citrate.
  7. The particulate composition according to one of the preceding claims, wherein the carboxylic acid salt or the carboxylic acid derivative is not acidic or acid-forming.
  8. The particulate composition according to any of the preceding claims, wherein the total content of carboxylic acid salt or carboxylic acid derivative is in the range of 0.01 wt.% to 1.5 wt.%, preferably 0.01 to 1.0 wt.%, more preferably 0.02 to 0.8 wt.%; more preferably 0.02 to 0.6 wt.%, more preferably 0.02 to 0.4 wt.%, and more preferably 0.02 to 0.2 wt.%, and most preferably 0.05 to 0.2 wt.%; in each case relative to the total weight of the particulate composition.
  9. The particulate composition according to any one of the preceding claims, wherein the polar polymer is a vinyl polymer, a polyester, a polyether, or a polyacrylate; preferably a vinyl polymer, a polyester, or a polyether; more preferably the polar polymer is selected from the group consisting of polyvinyl alcohol (PVOH), polyethylene glycol (PEG), polylactic acid (PLA), polyethylene glycol esters, butenediol-vinyl alcohol copolymer (BVOH), polyvinylpyrrolidone (PVP), and polyacrylamide (PAM); more preferably polyvinyl alcohol (PVOH), polyethylene glycol (PEG), polylactic acid (PLA), and polyethylene glycol esters, and even more preferably polyvinyl alcohol (PVOH).
  10. The particulate composition according to one of the preceding claims, wherein the polar polymer is water-soluble and/or biodegradable.
  11. The particulate composition according to any of the preceding claims, wherein the total polymer content is in the range of 0.001 to 1.0 wt.%; preferably 0.002 to 0.8 wt.%, more preferably 0.003 to 0.6 wt.%, 0.004 to 0.4 wt.%, and most preferably 0.005 to 0.2 wt.%; in each case relative to the total weight of the particulate composition.
  12. The particulate composition according to any of the preceding claims, comprising one or more additives; preferably the additives contain one or more of the following components: - sulfur; - ammonium sulfate; - at least one trace element.
  13. An additive as defined in any one of the preceding claims comprising components (i) and (ii) for producing a particulate composition according to any one of the preceding claims.
  14. Use of an additive after Claim 13 for the production of a particulate composition according to one of the Claims 1 until 12 .
  15. A method for producing a particulate composition according to one of the Claims 1 until 12 , wherein the process comprises the steps of: (a) providing an inhibitor composition containing an inhibitor, preferably a urease inhibitor and/or a nitrification inhibitor; (b) providing a urea-containing solution and/or melt; (c) granulating or pricking the urea-containing solution and/or melt to obtain a particulate composition; (d) optionally pre-cooling the particulate composition; (e) optionally classifying the particulate composition to obtain particle fractions; (f) optionally separating a particle fraction obtained in step (e) and recycling this separated particle fraction to a granulation or pricking device used in step (c); and (g) optionally post-cooling the particulate composition; wherein component (i) and component (ii) of an additive are added after Claim 13 are added independently of one another; preferably to the provided inhibitor composition or to the urea-containing solution and/or melt; wherein the inhibitor composition is added to the urea-containing solution and/or melt or brought into contact with the particulate composition.
  16. The procedure according Claim 15 , wherein the temperature of the urea-containing solution and/or melt is at least 120°C; preferably at least 125°C, and more preferably at least 130°C.
  17. The procedure according Claim 15 or 16 , wherein the addition of the additive to the urea-containing solution and/or melt takes place before or during step (c); preferably in step (c); more preferably before the solidification of the urea-containing solution and/or melt.
  18. The procedure according to one of the Claims 15 until 17 , wherein - the additive is added, preferably before or during step (c), as a solid, liquid or suspension; preferably as a solution; more preferably as an aqueous solution; even more preferably as a urea-containing aqueous solution; and/or - the inhibitor composition is added, preferably before or during step (c), as a liquid or suspension to the urea-containing solution and/or melt, preferably as a solution.
  19. The procedure according to one of the Claims 15 until 18 , wherein the addition of component (i) and component (ii) to the urea-containing solution and/or melt takes place together in one step or successively.
  20. Use of a particulate composition according to one of the Claims 1 until 12 as fertilizer.

Description

The invention relates to a particulate composition (urea particles) comprising, or substantially consisting of, urea, an inhibitor, preferably a urease inhibitor and/or a nitrification inhibitor, and an additive, wherein the additive comprises components (i) and (ii): (i) a carboxylic acid or an anhydride, salt, or derivative thereof; preferably a carboxylic acid salt or a carboxylic acid derivative, more preferably a carboxylic acid salt; and (ii) a polar polymer; preferably a water-soluble polar polymer. The invention further relates to a process for producing the particulate composition, an additive for a particulate composition, and the use of the particulate composition as a fertilizer. In conventional methods for producing urea particles, such as granulation or prilling, formaldehyde-based additives, such as urea-formaldehyde solutions, are typically added to the urea melt/solution before solidification. These additives are needed to improve granulation or prilling and thus the quality of the urea particles. Due to new regulations requiring higher nitrogen use efficiency (NUE) and a reduction in ammonia and greenhouse gas emissions, the demand for stabilized urea is increasing and will be much higher in the future. To produce stabilized urea, certain active ingredients must be added to the urea, particularly urease inhibitors, usually in the form of an inhibitor formulation. The most commonly used class of urease inhibitors are thiophosphoric triamides. Examples of commercially available thiophosphoric triamides are N-(n-butyl)thiophosphoric triamide (NBPT) and N-(n-propyl)thiophosphoric triamide (NPPT). Nitrification inhibitors are also frequently used. Nowadays, urea particles are primarily treated with inhibitor formulations by wholesalers, in small quantities, in a separate treatment process at mixing stations/systems. In this process, the urea particles are coated with the inhibitor formulations. After application, inhibitors such as thiophosphoric triamides are relatively stable at a storage temperature of 20°C and show degradation rates of 10-50% of the initially present inhibitor after one year of storage. For the nitrogen utilization efficiency of stabilized urea, a minimum concentration of the inhibitor in the urea particles must be ensured at the time of application in the field. In most regions, the potential to reduce nitrogen losses must be demonstrated/verified. For treating large quantities of urea with inhibitors, it is more economical to perform the treatment upstream in the value chain, directly during granulation or prilling. For example, the urea can be treated with an inhibitor formulation as a melt/solution before entering the granulator/prilling tower, during the granulation process, or during cooling. However, at a storage temperature of 20°C, an unexpectedly strong degradation of the inhibitor was observed, particularly of thiophosphoric triamides, when the urea particles are treated directly with the inhibitor during granulation or prilling, as described above. This observed rapid degradation means that the required minimum concentration of the inhibitor in the treated urea product cannot be achieved economically or practically with this method at the time of application in the field. The stabilized urea product would have to be applied immediately after its production, i.e., without intermediate storage, which is logistically impossible. Alternatively, the inhibitor would have to be added in a very high concentration, which is unacceptable from both an economic and environmental perspective. WO 2015 027244 A1 This concerns a urea-nitrogen stabilizer composition as well as processes, systems, and equipment for its production. The composition is incorporated into molten urea to obtain a formulation containing less biuret, N-methyl-2-pyrrolidone (NMP), nitrogen stabilizer, and/or impurities, resulting in an effective solid fertilizer. These compositions are useful for odor control. WO 2016 137815 A1 This concerns a urea granulate with a nitrogen stabilizer and a carrier system that is essentially homogeneously distributed throughout the entire granule thickness. Various processes for the production of urea granules are described, including pricking, fluidized bed, and drum granulation. The nitrogen stabilizer may contain a urease inhibitor such as NBPT, with the NBPT purity ranging from 90% to 99%. The nitrogen stabilizer It may also contain a nitrification inhibitor such as dicyandiamide (DCD). WO 2019 197183 A1 relates to a process for the production of a fertilizer composition comprising at least one urea-containing fertilizer and at least one (thio)phosphoric triamide. WO 2022 136360 A2 relates to a process for producing a homogeneous, solid, particulate, urea-based composition comprising urea and one or more additives in a urea production plant. WO 2002 020471 A2 This relates to a process for improving the compressive strength and impact strength of urea granules by addin