Sulfate Detection in Urea Samples via Ion Chromatography

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Solution Overview

Problem

Conventional scrubbers in urea plants fail to accurately detect sulfate concentrations below 1 ppm in complex samples containing urea, ammonia, and carbon dioxide, leading to potential corrosion and product specification issues due to sulfate seepage.

Innovation Solution

A method utilizing ion chromatography to analyze diluted samples, either liquid or solid, to determine sulfate concentrations by concentrating the samples and forming dilute solutions, enabling detection of sulfate levels as low as 1 ppm in samples with high urea, ammonia, and carbon dioxide content.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional detection methods are used, then the measurement process is simple, but sulfate concentrations below 1 ppm cannot be detected in complex samples

Engineering Contradiction:

Improvesulfate concentration detection capabilityVSAvoiddetection difficulty in complex samples

Core Design Contradiction:

Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The detection method is segmented into multiple distinct steps: sample concentration, dilution to working concentration, and ion chromatography analysis. This segmentation allows each step to be optimized independently, enabling detection of sulfate at concentrations below 1 ppm in complex urea samples containing ammonia and carbon dioxide

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Sample concentration is performed as a preliminary action before analysis. By concentrating the sample first, the sulfate content is increased to a detectable level, and interfering substances are removed or reduced, enabling subsequent accurate measurement by ion chromatography

Inventive Principle:

Principle #10Preliminary action

2Reliability

If sulfate monitoring is improved to detect levels below 1 ppm, then corrosion prevention and product quality are enhanced, but the analysis complexity and time increase

Engineering Contradiction:

Improvecorrosion prevention reliabilityVSAvoidanalysis time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

Sample concentration is performed in advance as a preliminary action, which not only enables detection of low sulfate concentrations but also removes interfering substances. This preliminary concentration step, when combined with automated ion chromatography, provides reliable corrosion prevention data while managing analysis time through efficient sample preparation

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Manual detection methods are replaced with automated ion chromatography analysis. This substitution provides highly reliable sulfate concentration measurements below 1 ppm for corrosion prevention, while the automation reduces manual intervention time and increases analysis efficiency

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

Effectively detects sulfate concentrations below 1 ppm in complex urea manufacturing process samples, preventing corrosion and ensuring product specifications are met by accurately measuring sulfate levels.

Implementation Method 1

The liquid sample is concentrated under conditions effective to reduce the liquid volume of the sample

Methodology Applied

Scientific EffectEvaporation: Evaporation

Implementation Method 2

The liquid sample is concentrated under conditions effective to reduce the liquid volume of the sample

Methodology Applied

Scientific EffectReduced pressure evaporation: Vacuum Distillation

Implementation Method 3

The dilute sample solution is analyzed with ion chromatography to determine if a concentration of sulfate is present

Methodology Applied

Scientific EffectIon chromatography: Chromatography

Implementation Method 4

The dilute sample solution is analyzed with ion chromatography to determine if a concentration of sulfate is present

Methodology Applied

Scientific EffectIon exchange: Ion Exchange

Data Source

PatentUS10330654B2Methods for determining low sulfate concentrations in synthetic urea samples, produced in a manufacturing process and containing high levels of impurities

Publication Date: 2019.06.25 SABIC AGRI NUTRIENTS CO

AI summary

In one aspect, disclosed herein is a method for determining sulfate concentration in a sample, comprising: a) providing a liquid sample comprising urea and at least one impurity; b) concentrating the liquid sample under conditions effective to reduce the liquid volume; c) forming a dilute sample solution by diluting the concentrated liquid sample of step b) in water; and d) analyzing the dilute sample solution of step c) with ion chromatography to determine if a concentration of sulfate is present in the provided liquid sample of step a); wherein the analyzing of step d) is capable of determining the presence of a sulfate concentration present in an amount less than about 1 ppm.