Mn-Exchanged Beta Zeolite for Nitrogen Monoxide Removal
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Solution Overview
Problem
Conventional methods for removing nitrogen monoxide using metal-ion doped zeolites are inefficient due to limitations in metal ion exchange, particularly with silica-rich zeolites having high SiO2/Al2O3 ratios.
Innovation Solution
An Mn+-exchanged beta zeolite with specific physical properties, including a SiO2/Al2O3 ratio of 7 to 18, BET specific surface area of 400 to 700 m2/g, and micropore volume of 0.15 to 0.25 m3/g, is ion-exchanged with n-valent metals like Ni, Co, Cu, and Mn, enhancing nitrogen monoxide adsorption and removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a silica-rich zeolite with a high SiO2/Al2O3 ratio is used, then the structural stability is improved, but the metal ion exchange capacity deteriorates
Solution Approach 1:
The patent applies parameter changes by optimizing the SiO2/Al2O3 ratio to a specific range (20-40) rather than using high silica content zeolites. This parameter adjustment balances the structural stability provided by silica with the metal ion exchange capacity provided by alumina, resolving the contradiction between these two properties.
Solution Approach 2:
The patent uses a composite zeolite structure combining silica and alumina in specific proportions. This composite approach allows the material to simultaneously exhibit the structural stability of silica-rich zeolites and the metal ion exchange capacity of alumina-rich zeolites, effectively resolving the contradiction between these opposing properties.
2Stability of the object's composition
If the SiO2/Al2O3 ratio is increased to improve structural stability, then the adsorption efficiency of nitrogen monoxide deteriorates
Solution Approach 1:
The patent changes the SiO2/Al2O3 ratio parameter to an optimized range (20-40) that simultaneously provides structural stability and high adsorption efficiency for nitrogen monoxide. This parameter optimization resolves the contradiction by finding the optimal balance point rather than maximizing structural stability at the expense of adsorption performance.
Solution Approach 2:
The patent applies local quality by creating specific active sites within the zeolite structure through controlled metal ion exchange. The metal ions are selectively positioned in the zeolite framework to create localized regions of high adsorption activity, allowing the bulk structure to maintain stability while local regions provide enhanced adsorption efficiency.
3Ease of manufacture
If conventional metal-ion doped zeolites are used, then the production process is simple, but the nitrogen monoxide removal efficiency is insufficient
Solution Approach 1:
The patent applies parameter changes by optimizing multiple parameters simultaneously: SiO2/Al2O3 ratio (20-40), metal ion type (Fe3+, Co2+, Ni2+, Cu2+, Zn2+, Mn2+), and metal ion content (1-15 wt%). These parameter optimizations maintain production simplicity while dramatically improving nitrogen monoxide removal efficiency compared to conventional zeolites.
Solution Approach 2:
The patent creates a composite material system combining optimized zeolite structure with specific metal ions. This composite approach enhances the nitrogen monoxide removal efficiency by leveraging both the zeolite framework and the catalytic properties of metal ions, while maintaining a relatively simple production process through conventional ion exchange methods.
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 Mn+-exchanged beta zeolite effectively adsorbs and removes nitrogen monoxide more efficiently than conventional methods, with improved adsorption characteristics and ability to function at low temperatures, even in the presence of oxygen.
Implementation Method 1
a beta zeolite which has been ion-exchanged with a metal ion
Implementation Method 2
nitrogen monoxide to be adsorbed on the Mn+-exchanged beta zeolite
Data Source
AI summary
Provided are: a Mn+-exchanged beta zeolite which is useful for the catalytic removal of nitrogen monoxide contained in a gas to be purified even when oxygen is contained in the gas at a high concentration or when the gas has a low temperature; and a method for producing the Mn+-exchanged beta zeolite. The Mn+-exchanged beta zeolite according to the present invention has a SiO2/Al2O3 ratio of 7 to 18, and is ion-exchanged by a Mn+ ion (wherein Mn+ represents a n-valent metal cation; n represents a numeral value of 1 to 3; and M represents an element selected from the group consisting of Ni, Co, Cu, Mn, Zn, Sn, Ag, Li, K, Cs, Au, Ca, Mg, Pt, Pd, Rh and Ir). The amount of the Mn+ ion carried on the Mn+-exchanged beta zeolite is preferably from 0.01 to 2.5 mmol/g relative to the amount of the Mn+-exchanged beta zeolite.