Urea Granule Dust Reduction via Carboxylic Acid Binders
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Solution Overview
Problem
Existing methods for producing NOx reducing agent AUS 32 solution from urea-containing compositions face challenges such as dust formation, mechanical instability, and health and environmental risks due to the use of formaldehyde and its derivatives, which also fail to meet strict purity standards for diesel exhaust fluid applications.
Innovation Solution
A method involving mixing water with a urea-containing particulate composition, including a combination of polymers or oligomers with amino groups and functionalized polyvinyl compounds, to produce a NOx reducing agent AUS 32 solution that meets ISO 22241 specifications without using formaldehyde or urea-formaldehyde condensates, thereby reducing dust formation and improving mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If formaldehyde or water-soluble addition and/or condensation products of formaldehyde and urea are used as granulation additives, then mechanical stability and dust reduction are improved, but health and environmental risks increase due to toxic properties
Solution Approach 1:
The patent removes formaldehyde and its derivatives from the granulation additive composition entirely, replacing them with non-toxic alternatives such as carboxylic acids (oxalic acid, succinic acid, adipic acid) and their esters or anhydrides. This extraction of the harmful substance while maintaining the functional benefits resolves the contradiction between mechanical stability and health/environmental safety.
Solution Approach 2:
The patent employs readily available, non-toxic carboxylic acids and their derivatives as granulation additives instead of persistent formaldehyde-based additives. These alternatives provide the necessary mechanical stabilization during granulation without leaving harmful residues in the final urea product, thus resolving the contradiction through substitution with safer, shorter-lived chemical entities.
2Strength
If aqueous urea solution with high water content is used for granulation, then particle size and mechanical properties are improved, but dust formation increases significantly
Solution Approach 1:
The patent introduces carboxylic acids and their derivatives as intermediary substances that facilitate the granulation process by acting as binding agents between urea particles. These intermediaries enable the use of higher water content solutions for granulation (improving mechanical properties) while preventing excessive dust formation through their film-forming and binding characteristics.
Solution Approach 2:
The patent modifies the chemical composition parameters of the granulation additive by using carboxylic acids with specific molecular weights and functional groups. These parameter changes allow for optimized water content in the urea solution (improving granule mechanical properties) while controlling dust emission through the specific binding characteristics of the carboxylic acid additives.
3Productivity
If urea granules are produced for fertilizer sector optimization, then production efficiency is improved, but purity standards for diesel exhaust fluid applications are not met due to aldehyde content
Solution Approach 1:
The patent extracts and eliminates aldehyde-containing components from the urea granule composition by replacing formaldehyde-based granulation additives with carboxylic acid-based alternatives. This extraction maintains the production efficiency benefits of optimized granulation while achieving the strict purity standards (aldehyde content < 5 mg/kg) required for diesel exhaust fluid applications.
Solution Approach 2:
The patent creates a composite granulation system combining urea with carboxylic acids and their derivatives, forming a composite material that maintains the mechanical and production efficiency advantages of conventional fertilizer-grade urea granules while achieving the high purity standards required for AUS 32 diesel exhaust fluid through the non-toxic, non-aldehyde-forming nature of the carboxylic acid components.
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 effectively produces a NOx reducing agent with improved mechanical stability, reduced dust formation, and compliance with strict purity standards, while minimizing health and environmental risks and transportation costs by decentralizing urea synthesis and using optimized urea granules for the fertilizer sector.
Implementation Method 1
A method involving mixing water with a urea-containing particulate composition, including a combination of polymers or oligomers with amino groups and functionalized polyvinyl compounds
Implementation Method 2
including a combination of polymers or oligomers with amino groups and functionalized polyvinyl compounds
Implementation Method 3
polymers or oligomers with amino groups
Data Source
AI summary
The invention relates to a method for producing an NOx reductant AUS 32 solution (diesel exhaust fluid) comprising at least the mixing of water and a particulate composition containing (i) urea; and an additive comprising component (ii): (ii) combination of at least one polymer or oligomer containing amino groups and at least one functionalized polyvinyl compound; wherein the weight percentage of component (i) in the particulate composition is greater than 60 wt% and the weight percentage of component (ii) in the particulate composition is less than 1 wt% and wherein a urea solution is obtained and the weight percentage of component (i) in the obtained urea solution is between 31 wt% and 34 wt%.