Urea Fertilizer Crush Strength via Polymer Matrix
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Solution Overview
Problem
Conventional urea fertilizers often suffer from low crush strength and high biuret content, which can lead to clumping and storage issues, and biuret toxicity in plants.
Innovation Solution
A solid, flowable fertilizer is developed by combining a urea-formaldehyde polymer with a urea source, such as molten or solid urea, and granulating it to enhance crush strength and reduce biuret content, using polymethyl urea resin with reactive methylol groups and optionally blending with an aqueous urea formaldehyde solution or adding urease inhibitors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional urea fertilizer is used, then nitrogen delivery is provided, but crush strength is low and biuret content is high
Solution Approach 1:
The patent combines urea with a polymeric material (such as polyacrylamide or other water-soluble polymers) to create a composite fertilizer formulation. This composite structure provides the desired crush strength while the polymer matrix helps control biuret formation and release, simultaneously addressing both the strength requirement and the biuret content issue.
Solution Approach 2:
The patent modifies the physical and chemical parameters of the fertilizer by controlling granulation conditions, moisture content, and polymer-to-urea ratios. By adjusting these parameters during manufacturing, the formulation achieves optimal crush strength while minimizing biuret content through controlled reaction conditions and proper material selection.
2Reliability
If granulated solid urea is stored under humid conditions, then nitrogen is available, but clumping occurs and storage properties deteriorate
Solution Approach 1:
The patent introduces a polymeric material as an intermediary substance between urea granules. This polymer acts as a spacer and moisture barrier, preventing direct contact between urea granules that would lead to clumping. The intermediary material maintains granule separation while allowing nitrogen release, thus improving storage stability without compromising nitrogen availability.
Solution Approach 2:
The patent utilizes porous or hydrophilic polymeric materials that can absorb excess moisture while maintaining air circulation. These porous structures allow controlled moisture management, preventing the conditions that lead to clumping while still permitting nitrogen delivery to plants, thereby improving both storage stability and nitrogen availability.
3Object-generated harmful factors
If aqueous urea formaldehyde solution is used, then biuret content can be controlled, but crush strength and storage properties are poor
Solution Approach 1:
The patent employs phase transition during the granulation process, where the aqueous urea formaldehyde solution is applied to urea granules and then dried. The controlled evaporation and drying process transforms the liquid binder into a solid matrix that provides crush strength while maintaining the low biuret content benefits of the aqueous solution formulation.
Solution Approach 2:
The patent replaces the need for high mechanical compression (which would be required to achieve sufficient crush strength in conventional formulations) with chemical bonding through the polymeric material. The polymer provides structural integrity through molecular adhesion rather than mechanical compression, allowing low biuret content formulations to achieve adequate crush strength without excessive mechanical processing.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides a fertilizer with improved crush strength, reduced biuret content, and enhanced storage and handling properties, preventing clumping and minimizing biuret toxicity, while maintaining effective nitrogen delivery for plant growth.
Implementation Method 1
The UFP absorbs ammonia, which may prevent the undesirable formation of biuret.
Implementation Method 2
combining a solid, flowable urea formaldehyde polymer (UFP) with a urea source such as molten urea and/or solid urea and granulated to produce a solid fertilizer
Data Source
AI summary
A solid urea fertilizer prepared by mixing a solid, flowable, urea formaldehyde polymer with a urea source, such as molten or solid urea to form a fertilizer that has favorable crush strength characteristics, low biuret content, and/or desirable storage and handling properties. The urea fertilizer may contain additionally, an aqueous urea formaldehyde solution or mixture. Optionally, the fertilizer may contain a urease inhibitor and/or a nitrification inhibitor.