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EP-4121402-B1 - METHOD OF FORMING FERTILIZER COMPOSITIONS HAVING SLOW-RELEASE NITROGEN COMPOUNDS

EP4121402B1EP 4121402 B1EP4121402 B1EP 4121402B1EP-4121402-B1

Inventors

  • MACDONALD, Curtis James
  • VELEZ, Stephanie Von Ville
  • INGLISH, David Patrick
  • OWUSU-ADOM, KWAME
  • THOMPSON, HAROLD E.

Dates

Publication Date
20260506
Application Date
20210319

Claims (15)

  1. A method of forming a fertilizer composition having slow-release nitrogen compounds, the method comprising: forming a molten mixture of urea, formaldehyde, resin modifier, and one or more of an acid catalyst and an emulsifier; and adjusting, as needed, the temperature of the molten mixture to initiate a reaction of the urea and the formaldehyde to form a fertilizer composition; and wherein the resin modifier comprises polyethylene wax; the acid catalyst comprises one or more of iodic acid, oxalic acid, chlorous acid, phosphoric acid, arsenic acid, chloroacetic acid, citric acid, hydrofluoric acid, nitrous acid, formic acid, and lactic acid; and the emulsifier comprises one or more of star macromolecule polymers and fatty acid derivatives.
  2. The method according to any preceding claim, wherein the resin modifier comprises crystalline polyethylene wax.
  3. The method according to any preceding claim, wherein the acid catalyst is a dilute acid catalyst.
  4. The method according to claim 3, wherein the weak acid catalyst has a pK a value of about 0.5 to about 3.5.
  5. The method according to claim 4, wherein the weak acid comprises phosphoric acid.
  6. The method according to any of claims 4 or 5, wherein the molten mixture comprises about 4.5 * 10 -5 moles to about 4.0 * 10 -3 moles of the weak acid catalyst per mole of formaldehyde.
  7. The method according to any of claims 4 to 6, wherein the molten mixture comprises about 1.3 * 10 -3 moles to about 1.7 * 10 -3 moles of the weak acid catalyst per mole of formaldehyde.
  8. The method according to any preceding claim, wherein the molten mixture comprises about 500 parts-per-million ("ppm") to about 2,000 ppm of the star macromolecule polymer and about 600 ppm to about 4,000 ppm of the fatty acid derivative.
  9. The method according to any preceding claim, wherein the reaction of the urea and the formaldehyde occurs at an initial temperature of about 110 °C to about 125 °C and at a second temperature of about 125 °C to about 135 °C; and wherein the initial temperature is held for about 10 minutes to about 40 minutes and wherein the second temperature is held for about 10 minutes to about 20 minutes.
  10. The method according to any preceding claim, wherein the mole ratio of urea to formaldehyde is about 2.4:1 or greater.
  11. The method according to any preceding claim, wherein the mole ratio of urea to formaldehyde is about 3.1:1 to about 3.35:1.
  12. The method according to any preceding claim, wherein the molten methylene urea mixture comprises about 2% by weight to about 20% by weight of the resin modifier, and wherein the resin modifier comprises a crystalline polyethylene wax comprising one or more of: a molecular weight of about 600 to about 1,200; a polydispersity of about 1.02 to about 1.7; and a degree of crystallinity of about 65% to about 96%.
  13. The method according to any preceding claim, wherein the fertilizer composition comprises at least one of methylenediurea ("MDU") and dimethylenetriurea ("DMTU") and wherein the at least one of MDU and DMTU comprises about 35% or more of the total nitrogen in the fertilizer composition; and wherein the fertilizer composition comprises about 8% or less cold-water insoluble nitrogen.
  14. The method according to any preceding claim, wherein the fertilizer composition is sprayed on an inert carrier to form a granule, the inert carrier comprising a rice hull.
  15. The method according to claim 14, wherein the granules further comprise one or more of potassium sulfate, ammonium sulfate, 3,6-Dichloro-2-methoxybenzoic acid (dicamba), 2,4-dichlorophenoxy acetic acid (2,4-D), methyl chlorophenoxy propionic acid (MCPP-P), calcium nitrate, ammonium sulfate, sulfur-coated urea, isobutylidene diurea, ammonium nitrate, ureaform, urea formaldehyde reaction product, urea, anhydrous ammonia, ammonium polyphosphate, monoammonium phosphate, diammonium phosphate, potassium nitrate, potassium sulfate, polymer coated urea, micro elements, mono-ammonium phosphate, potassium chloride, and mixtures thereof, pesticides, micronutrients, biostimulants, macronutrients, and inert solid carriers.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application claims the priority benefit of U.S. Provisional Patent App. Serial No. 62/992,271, titled "FERTILIZER COMPOSITIONS HAVING SLOW-RELEASE NITROGEN COMPOUNDS AND METHODS OF FORMING THEREOF", filed March 20, 2020. TECHNICAL FIELD The present disclosure relates generally to methods of making fertilizer compositions having slow-release nitrogen compounds with a molten process. BACKGROUND It is desirable for fertilizer compositions to include slow-release nitrogen compounds to provide plants with an extended release of nutrients, minimize leaching of nutrients into the ground, and minimize the number of fertilizer applications required for optimal plant growth. However, conventional production of slow-release nitrogen compounds suffer from a number of undesirable attributes. For example, conventional production of slow-release nitrogen compounds, such as by aqueous processes or by coating processes, can have complicated production processes with multiple time consuming steps, be energy intensive, and form a blend of nitrogen compounds having undesirable ratios of desirable slow-release nitrogen compounds to other nitrogen compounds such as cold-water insoluble nitrogen compounds. WO 2019/153775 discloses a sustained-release and controlled-release fertilizer with a core-shell structure, comprising a fertilizer granule core; and a polyurea formaldehyde coating layer made by reacting urea and formaldehyde in basic and in acidic conditions, to produce a coating starting material liquid, which is sprayed on a fertilizer granule. SUMMARY According to one embodiment, a method of forming a fertilizer composition having slow release nitrogen compounds includes forming a molten mixture of urea, formaldehyde, resin modifier, and one or more of an acid catalyst and an emulsifier and adjusting, as needed, the temperature of the molten mixture to initiate a reaction of the urea and the formaldehyde to form the fertilizer composition; and wherein the resin modifier comprises polyethylene wax; the acid catalyst comprises one or more of iodic acid, oxalic acid, chlorous acid, phosphoric acid, arsenic acid, chloroacetic acid, citric acid, hydrofluoric acid, nitrous acid, formic acid, and lactic acid; and the emulsifier comprises one or more of star macromolecule polymers and fatty acid derivatives. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts a contour plot illustrating the ratio of urea to formaldehyde in several example compositions.FIG. 2A depicts a contour plot illustrating the quantities of MDU and DMTU formed from the example compositions of FIG. 1.FIG. 2B depicts a contour plot illustrating the quantities of cold-water insoluble nitrogen ("CWIN") formed from the example compositions of FIG. 1.FIG. 3 depicts a contour plot illustrating the viscosity of the examples compositions of FIGS. 1, 2A, and 2B.FIG. 4 depicts an illustration of a resin modifier occluding methylene urea resin products.FIG. 5 depicts a graph illustrating the dynamic viscosity of methylene urea resin products as a function of acid catalyst concentration.FIGS. 6A and 6B depict scanning electron microscopy images showing the effect of a high temperature defoaming agent on methylene urea resin products.FIG. 7 depicts a graph illustrating the dynamic viscosity of methylene urea resin products with different defoaming agents.FIG. 8 is a scanning electron microscopy image of an example composition.FIG. 9 depicts a graph showing the solidification curve of Example 6.FIG. 10 depicts a graph showing the particle size distribution of example 6. DETAILED DESCRIPTION The present disclosure generally describes methods of forming fertilizer compositions having slow-release nitrogen compounds using a molten process. As used herein, slow-release nitrogen compounds mean nitrogen compounds which provide a slower and/or longer duration release of nitrogen to plants after the compounds are applied to plants. Generally, fertilizers including slow-release nitrogen compounds can make nitrogen available to plants over a period of weeks to months. The slow-release nitrogen compounds formed from the methods generally described in the present disclosure include desirable short-chain methylene urea products such as methylenediurea ("MDU") and dimethylenetriurea ("DMTU") as well as longer-chain cold-water insoluble nitrogen compounds. As can be appreciated, slow-release nitrogen compounds such as MDU and DMTU can be formed from chain building of urea and formaldehyde under molten conditions. Under such conditions, urea and formaldehyde can undergo a series of reactions which produce methylene urea products having varying chain lengths. For example, a urea molecule can react with a formaldehyde molecule to produce a monomethylol urea molecule. The monomethylol urea molecule can then react with another urea molecule to form methylenediurea or MDU. As can be appreciated, continued reaction of the urea molecules, formaldeh