Deep Eutectic Solvent for Irreversible NOx Trapping
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Solution Overview
Problem
Conventional filtration materials, such as activated carbons and basic compounds, are inefficient in filtering nitrogen oxides (NOx), particularly NO2, at low temperatures and in confined spaces, and can be corrosive, while existing deep eutectic solvents (DESs) exhibit reversible adsorption and toxicity issues.
Innovation Solution
A deep eutectic solvent (DES) comprising a halogenated salt of ammonium, phosphonium, or sulfonium combined with a compound of formula R1R2R3N, where R1 is a linear or branched C1 to C5 alkyl radical substituted with hydroxyl groups, is used to effectively and irreversibly trap NOx, including NO2, under conditions representative of ambient air.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional filtration materials (activated carbons, zeolites, basic compounds) are used to filter NOx, then the filtration system is simple and non-toxic, but the filtration efficiency for NO2 is very low at low temperatures
Solution Approach 1:
The patent uses a composite material system consisting of a deep eutectic solvent formed by combining a halogenated ammonium salt with a polyhydric alcohol. This composite material achieves high NO2 filtration efficiency through the synergistic interaction between the two components, resolving the contradiction between filtration efficiency and material simplicity.
Solution Approach 2:
The patent changes the chemical parameters of the filtration material by using a deep eutectic solvent system with specific halogenated ammonium salts and polyhydric alcohols. This parameter change enables the material to effectively filter NO2 at low temperatures, overcoming the limitations of conventional materials.
2Reliability
If triethanolamine is used to trap NO2, then the adsorption capacity is high, but the adsorption is mostly reversible causing NO2 release into ambient air
Solution Approach 1:
The patent employs a deep eutectic solvent system that forms irreversible adducts with NO2, effectively trapping the pollutant without releasing it back into the ambient air. The solvent system acts as a disposable trapping mechanism that maintains trapped NO2 permanently, eliminating the harmful release issue.
Solution Approach 2:
The patent converts the potentially harmful reversible adsorption mechanism into a beneficial irreversible trapping mechanism. By using the deep eutectic solvent system, the NO2 that would otherwise be released is permanently trapped, transforming the harm of reversible adsorption into the benefit of permanent sequestration.
3Reliability
If deep eutectic solvents based on urea are used for NOx trapping, then the adsorption capacity is improved, but the urea decomposes into ammonia which is toxic and odorous
Solution Approach 1:
The patent extracts the problematic urea component from the deep eutectic solvent system and replaces it with polyhydric alcohols. This extraction eliminates the ammonia decomposition issue while maintaining the beneficial NOx adsorption performance through the alternative solvent components.
Solution Approach 2:
The patent introduces polyhydric alcohols as intermediary substances that form deep eutectic solvents with halogenated ammonium salts. These intermediaries provide the necessary NOx trapping capability without undergoing harmful decomposition, serving as safe alternatives to urea-based systems.
4Stability of the object's composition
If triethanolamine is used at temperatures below its melting point (21.6°C), then the material remains solid, but the adsorption efficiency is reduced
Solution Approach 1:
The patent changes the temperature parameter by operating the deep eutectic solvent system at temperatures above the melting point of triethanolamine, allowing the material to remain in a liquid state and maintain high adsorption efficiency. This parameter change resolves the contradiction between phase stability and adsorption performance.
Solution Approach 2:
The patent uses a composite deep eutectic solvent system where the combination of halogenated ammonium salt and polyhydric alcohol creates a eutectic mixture with lowered melting point. This composite material remains liquid at operational temperatures, maintaining high adsorption efficiency while providing phase stability.
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 DES achieves high adsorption efficiency for NOx, with reduced release into the ambient air, operating effectively in a wide range of temperatures and concentrations, and is non-toxic and simple to synthesize.
Implementation Method 1
a deep eutectic solvent (DES) comprising at least: a halogenated ammonium, phosphonium or sulfonium salt, and a compound of formula (I) R1R2R3N with R1 being a linear or branched C1 to C5 alkyl radical substituted by one or more hydroxyl group(s), R2 and R3 being independently of each other chosen from a hydrogen atom and a linear or branched C1 to C5 alkyl radical which may be substituted by one or more hydroxyl group(s), to trap at least one gaseous nitrogen oxide called NOx
Data Source
Figure 1~2
AI summary
The present invention relates to the use of a deep eutectic solvent comprising at least one halogenated ammonium, phosphonium or sulfonium salt, and a compound of formula (I) R 1 R 2 R 3 N with R1 being a linear or branched C1 to C5 alkyl radical substituted with one or more hydroxyl group(s), R 2 and R 3 being chosen, independently of one another, from a hydrogen atom and a linear or branched C1 to C 5 alkyl radical that may be substituted with one or more hydroxyl group(s), in order to trap at least one gaseous nitrogen oxide, referred to as NOx. The invention also relates to a gaseous fluid filtration system and to a process for purifying a gaseous fluid.