Urea Granulate Compressibility Reduction via Biodegradable Polymer Additives

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Solution Overview

Problem

Urea granulates are prone to crushing and caking during storage and transport, especially in tropical conditions, leading to dust problems and moisture sensitivity, and existing additives either require large quantities, pose toxicity risks, or cause undesirable effects like foam formation or color changes in industrial applications.

Innovation Solution

Adding a mixture of at least two different polymers to the urea melt, including a poly-alkenyl compound and a polymer with hydroxyl, carboxylic acid, amine, or amide groups, such as polyvinyl alcohol or polyaspartic acid, significantly reduces compressibility and caking tendencies while maintaining low moisture sensitivity and avoiding environmental burdens.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If formaldehyde derivatives are added to improve crushing strength, then the crushing strength increases, but the composition becomes poisonous and difficult to handle

Engineering Contradiction:
Improvecrushing strengthVSAvoidpoisonous properties
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent replaces toxic formaldehyde derivatives with a biodegradable polymer additive that is environmentally friendly and safe to handle. The polymer serves as a temporary protective agent during storage and transport that does not persist as a harmful substance, effectively substituting a short-lived functional additive for a toxic one.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent changes the chemical nature of the additive from toxic formaldehyde derivatives to biodegradable polymers with specific molecular weights and compositions. This parameter change in the additive's chemical structure eliminates toxicity while maintaining or improving the crushing strength enhancement function.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If poly(vinyl acetate)/surfactant combination is used to reduce caking tendency, then caking is reduced, but foam formation increases in industrial applications

Engineering Contradiction:
Improvecaking tendencyVSAvoidfoam formation
Core Design Contradiction:
Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The patent removes the surfactant component from the additive combination that causes foam formation in industrial applications. By using only the poly(vinyl acetate) polymer without the surfactant, the patent eliminates the harmful foam generation while retaining the caking prevention benefit.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses a biodegradable polymer additive that serves its protective function temporarily during storage and transport, then degrades without causing long-term environmental harm or unwanted side effects like foam formation in subsequent industrial applications.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Stability of the object's composition

If inorganic salts are added to decrease compressibility, then compressibility decreases, but pH decreases strongly when dissolving urea in water

Engineering Contradiction:
ImprovecompressibilityVSAvoidpH decrease
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The patent replaces inorganic salts with biodegradable organic polymers that provide compressibility reduction without the harmful side effect of pH decrease. The organic polymers degrade into benign substances that do not affect the pH of water solutions.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent changes the additive type from inorganic salts to organic polymers, fundamentally altering the chemical parameters of the system. This parameter change eliminates the pH-decreasing effect while maintaining the compressibility reduction benefit through the polymer's physical properties.

Inventive Principle:
Principle #35Parameter changes

4Stability of the object's composition

If polyvinyl alcohol is used to prevent caking, then caking is prevented, but dust formation increases due to internal moisture migration

Engineering Contradiction:
Improvecaking preventionVSAvoiddust formation
Core Design Contradiction:
Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The patent uses a composite additive system combining poly(vinyl acetate) polymer with specific molecular weight and composition, creating a material that prevents caking through its polymer structure without causing the moisture migration issues that lead to dust formation. The composite nature of the polymer provides multiple functional benefits simultaneously.

Inventive Principle:
Principle #40Composite materials

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 polymer mixture substantially decreases compressibility, caking, and re-crystallization of urea granulates, enhancing their handling and storage stability with minimal environmental impact and no adverse effects on industrial applications.

Implementation Method 1

a first polymeric compound and a second polymeric compound are added to a urea melt... substantially decreases compressibility

Methodology Applied
Scientific EffectCompressibility reduction:

Implementation Method 2

the tendency of caking... is substantially lower than of untreated urea... during storage and handling

Methodology Applied
Scientific EffectMoisture migration prevention:

Implementation Method 3

dust formation by re-crystallization of the composition is substantially lower than of untreated urea

Methodology Applied
Scientific EffectRe-crystallization prevention: Crystallisation

Data Source

PatentUS7824565B2Urea composition having reduced compressibility, cake formation and dust formation, and process for its preparation
Publication Date: 2010.11.02 YARA INTERNATIONAL ASA

AI summary

Colorfast urea composition having reduced compressibility, cake formation and tendency of re-crystallization of the urea granulate, wherein the granulate further contains at least two different biodegradable polymers, of which at least one polymer is preferably a polyalkenyl amine compound. The other polymer is preferably polyaspartic acid or polyvinyl alcohol. The invention further relates to a process for the preparation of such a urea composition.