Sulfur Component Analysis Using UV Fluorescence and NO Oxidation
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Solution Overview
Problem
Current methods for measuring sulfur component concentrations in sample gases, such as SO2, face interference from nitrogen monoxide (NO) due to overlapping fluorescence spectra, leading to measurement errors and requiring complex and costly setups for interference removal.
Innovation Solution
Oxidizing NO to nitrogen dioxide (NO2) within the sample gas stream before ultraviolet illumination, which eliminates interference and allows for precise measurement of sulfur components like SO2 without the need for additional filtration or subtraction methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a gas filter scheme is used to remove NO interference, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts and removes the harmful NO component from the sample gas stream by introducing an oxidizing agent (ozone or oxygen) to convert NO to NO2, which does not interfere with the fluorescence detection of SO2. This eliminates the need for complex gas filters while maintaining measurement precision.
Solution Approach 2:
The patent changes the chemical state of NO by oxidizing it to NO2, thereby altering its spectral properties so that it no longer absorbs or emits fluorescence at the detection wavelength, eliminating interference without requiring additional filtering components.
2Measurement precision
If conventional pretreatment facilities are installed to remove interferential components, then measurement precision is improved, but facility cost and apparatus scaling increase
Solution Approach 1:
The patent removes the harmful interferential component (NO) through chemical oxidation in a simple reaction zone, eliminating the need for expensive conventional pretreatment facilities such as Perma-pure driers and high-temperature combustion furnaces.
Solution Approach 2:
The patent changes the chemical composition of the sample gas by oxidizing NO to NO2, thereby transforming the interferential component into a non-interfering form that can be detected alongside SO2 without requiring complex pretreatment infrastructure.
3Measurement precision
If fluid modulation method is used to eliminate interferential influence, then measurement precision is improved, but responsiveness to sudden concentration changes deteriorates
Solution Approach 1:
The patent performs preliminary oxidation of NO to NO2 in the sample gas stream before the gas enters the fluorescence detection cell. This preliminary treatment ensures that NO interference is eliminated before measurement, allowing for immediate and accurate detection of SO2 concentration changes without the need for modulation or subtraction methods.
4Measurement precision
If gas filter scheme is used to remove NO interference, then measurement precision is improved, but long-term reliability deteriorates due to chronological changes in NO gas properties
Solution Approach 1:
The patent changes the chemical state of the interferential component from NO to NO2 through oxidation. This parameter change is stable and irreversible, ensuring that the interference removal effect remains consistent over long-term continuous operation without degradation due to chronological changes in gas properties.
Solution Approach 2:
The patent converts the harmful NO component into beneficial NO2 by oxidation. The NO2 produced does not interfere with SO2 fluorescence detection and can even serve as a visual indicator that the oxidation process is functioning correctly, providing long-term reliable operation.
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
This approach ensures high precision and efficiency in measuring sulfur component concentrations over long-term continuous measurements, simplifying the apparatus and reducing costs by effectively removing NO interference through oxidation, thereby improving measurement accuracy and efficiency.
Implementation Method 1
adding ozone into a sample gas to thereby oxidize NO included in the sample gas
Implementation Method 2
a sample gas is illuminated with ultraviolet to detect an intensity of fluorescence caused by the ultraviolet illumination
Data Source
AI summary
An analysis method and analysis apparatus involve analysis for a sulfur component using ultraviolet fluorescence capable of removing the interferential influence of NO with good efficiency and certainty to thereby measure a concentration of only sulfur components such as SO2 and others even in continuous measurement over a long term with a high precision. An analysis method involves analysis for a sulfur component using ultraviolet fluorescence. A sample gas is illuminated with ultraviolet and fluorescence is emitted by the ultraviolet illumination and detected to measure concentrations of sulfur components including at least SO2 in the sample gas. NO, which is an interferential component in the sample gas, is oxidized to nitrogen dioxide, followed by the illuminating of the sample gas with ultraviolet.