Highly available waste based nitrogen fertilizer
First Claim
1. A method of preparing granular slow release nitrogen fertilizer, exhibiting substantially complete nitrogen availability, by coreacting dry conditioned nitrogenous particulate wastes, and reactive ureaformaldehyde oligomer as free flowing solids, the method comprising:
- (a) dry conditioning an organic nitrogenous waste by drying and comminuting until it forms a mass of individual particles, comprising between 1 and 25 percent moisture, and between 1 and 13 percent nitrogen, and exhibits properties of tumbling freely in a rotating cylinder and passing through a U.S. Standard 4 Mesh Screen;
(b) forming a reactive ureaformaldehyde liquid oligomer by heating aqueous urea and formaldehyde combined in a molecular ratio between 1.3 and 3.0 to 1, at a pH between 5 and 8, at a temperature between 40 and 95°
C., until the liquid oligomer is sufficiently reactive to solidify in a period of time between 1 and 20 minutes when heated to 105°
C.;
(c) charging the dry conditioned organic nitrogenous particulate waste to a cylinder rotating around its center axis at a speed sufficient to form the waste into granules, while concomitantly adding to the waste an amount of reactive ureaformaldehyde liquid oligomer sufficient to provide between 15 and 85 percent of the nitrogen of the fertilizer, and continuing to rotate the cylinder until the reactive oligomer is evenly distributed in the waste granules;
(d) initiating the coreaction of the dry conditioned nitrogenous waste and the reactive ureaformaldehyde oligomer by admixing therewith sufficient mineral acid in the rotating cylinder to provide therein a pH between 1.5 and 6.5, and heating the admixture to a temperature between 45 and 110°
C.;
(e) continuing the coreaction until between 35 and 75 percent of the nitrogen is insoluble in water; and
(f) neutralizing the coreacted waste and ureaformaldehyde oligomer to a pH between 6 and 8 and cooling to a temperature lower than 45°
C. after a coreaction time between 4 and 30 minutes, while the availability of the slow release nitrogen is substantially complete.
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Abstract
A new method of preparing granular slow release nitrogen fertilizer, exhibiting substantially complete nitrogen availability as a plant nutrient, from nitrogenous organic wastes, such as animal excretia, by coreacting particulate dry conditioned nitrogenous organic waste and reactive ureaformaldehyde oligomer; and the slow release fertilizer exhibiting improved nitrogen availability prepared by the new method. The preconditioning of the waste and the preparation of the reactive oligomer are arranged so that the method for forming the new composition is effectively carried out in a damp dry, free flowing particulate system. Parameters are provided for: dry conditioning the wastes, oligomer forming, coreacting, and granulating.
48 Citations
19 Claims
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1. A method of preparing granular slow release nitrogen fertilizer, exhibiting substantially complete nitrogen availability, by coreacting dry conditioned nitrogenous particulate wastes, and reactive ureaformaldehyde oligomer as free flowing solids, the method comprising:
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(a) dry conditioning an organic nitrogenous waste by drying and comminuting until it forms a mass of individual particles, comprising between 1 and 25 percent moisture, and between 1 and 13 percent nitrogen, and exhibits properties of tumbling freely in a rotating cylinder and passing through a U.S. Standard 4 Mesh Screen; (b) forming a reactive ureaformaldehyde liquid oligomer by heating aqueous urea and formaldehyde combined in a molecular ratio between 1.3 and 3.0 to 1, at a pH between 5 and 8, at a temperature between 40 and 95°
C., until the liquid oligomer is sufficiently reactive to solidify in a period of time between 1 and 20 minutes when heated to 105°
C.;(c) charging the dry conditioned organic nitrogenous particulate waste to a cylinder rotating around its center axis at a speed sufficient to form the waste into granules, while concomitantly adding to the waste an amount of reactive ureaformaldehyde liquid oligomer sufficient to provide between 15 and 85 percent of the nitrogen of the fertilizer, and continuing to rotate the cylinder until the reactive oligomer is evenly distributed in the waste granules; (d) initiating the coreaction of the dry conditioned nitrogenous waste and the reactive ureaformaldehyde oligomer by admixing therewith sufficient mineral acid in the rotating cylinder to provide therein a pH between 1.5 and 6.5, and heating the admixture to a temperature between 45 and 110°
C.;(e) continuing the coreaction until between 35 and 75 percent of the nitrogen is insoluble in water; and (f) neutralizing the coreacted waste and ureaformaldehyde oligomer to a pH between 6 and 8 and cooling to a temperature lower than 45°
C. after a coreaction time between 4 and 30 minutes, while the availability of the slow release nitrogen is substantially complete. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A continuous method of preparing spheroid controlled release nitrogen fertilizer exhibiting substantially complete nitrogen availability in one growing season, by coreacting dry conditioned nitrogenous animal excretia and reactive ureaformaldehyde liquid oligomer, the method comprising:
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(a) dry conditioning the nitrogenous animal excretia by drying and comminuting until a mass of individual, free flowing, particles are formed comprising between 10 and 20 percent moisture and between 2 and 5 percent nitrogen, and exhibiting properties of tumbling freely in a rotating cylinder and passing through a U.S. Standard 6 Mesh Screen; (b) forming a reactive ureaformaldehyde liquid oligomer by heating aqueous urea and formaldehyde combined in a molecular ratio between 1.3 and 2.0 at a temperature between 1.5 and 2.0 at a temperature between 60 and 95°
C., until the liquid oligomer is sufficiently reactive to solidify in a period of time between 4 and 8 minutes when heated to 105°
C.;(c) continuously charging the dry conditioned animal excretia to a rotating horizontal cylinder, exhibiting a length to diameter ratio between 3 and 6, rolling said excretia therein at a cylinder rim speed between 0.2 and 2.0 meters per second to form the excretia into spheroids, concomitantly applying to the excretia granules an amount of reactive ureaformaldehyde oligomer sufficient to provide between 45 and 70 percent of the fertilizer nitrogen, and continuing to rotate the cylinder until the reactive oligomer is evenly distributed in the excretia spheroids; (d) initiating the coreaction of the dry conditioned animal excretia and the reactive ureaformaldehyde oligomer by continuously admixing therewith sufficient mineral acid to provide a pH in the rotating cylinder between 2.0 and 4.0, and heating to a temperature between 70 and 90°
C.;(e) continuing the coreaction until between 45 and 70 percent of the fertilizer nitrogen is insoluble in water; (f) neutralizing the coreacted animal excretia and ureaformaldehyde oligomer spheroids to a pH between 6.5 and 7.2 by continuously admixing in the rotating cylinder sufficient base, and cooling to a temperature lower than 45°
C. after a coreaction time between 10 and 20 minutes while the Availability Index of the nitrogen is between 65 and 85 percent. - View Dependent Claims (18, 19)
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Specification