Core-Shell Zeolite Adsorbent for Humid Gas Capture
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing core-shell zeolite materials have insufficient shell coverage and hydrophobicity, leading to reduced adsorption of target substances in the presence of water, and they exhibit low heat resistance.
Innovation Solution
A core-shell adsorbent with a zeolite core and a silicate-based oxide shell having an SAR of 750 or more, a zeolite structure, and a peak intensity ratio (I Si-OH /I Si-O ) of 3.0 or less, ensuring high hydrophobicity and heat resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a zeolite core is surrounded by a silicate-based oxide shell to improve hydrophobicity and maintain CO2 adsorption in the presence of water, then the adsorption capacity is improved, but the shell coverage rate is insufficient and many Si-OH bonds remain on the shell surface
Solution Approach 1:
The patent optimizes the SAR value parameter of the silicate-based oxide shell to 750 or more, and controls the Si-OH peak intensity ratio to 3.0 or less. These parameter changes transform the shell properties to achieve both high coverage rate and sufficient hydrophobicity, resolving the contradiction between adsorption capacity and shell coverage precision.
2Reliability
If the shell surface is silylated to improve hydrophobicity, then the hydrophobicity is improved, but the heat resistance becomes low and applications are limited
Solution Approach 1:
The patent changes the fundamental parameter of the shell material by selecting silicate-based oxide with SAR ≥750, which inherently provides both hydrophobicity and heat resistance. This parameter change avoids the heat resistance problem associated with silylation while maintaining sufficient hydrophobicity through the high SAR value and controlled Si-OH ratio.
3Quantity of substance
If FAU zeolite is used as a CO2 adsorbent material, then the adsorption ability is good, but competitive adsorption between CO2 and water occurs when water is present, resulting in decreased CO2 adsorption
Solution Approach 1:
The silicate-based oxide shell acts as an intermediary between the zeolite core and the external environment. It selectively allows CO2 to pass through while blocking water molecules, thereby preventing competitive adsorption. The shell's hydrophobicity (achieved through SAR ≥750 and controlled Si-OH ratio) enables it to repel water while maintaining CO2 diffusion, resolving the harmful effect of competitive adsorption.
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 adsorbent maintains a high adsorption capacity for target substances like CO2, NOx, and HC even in the presence of water, with enhanced heat resistance and hydrophobicity.
Implementation Method 1
the shell having a zeolite structure and a ratio (I Si-OH /I Si-O ) of a peak intensity I Si-OH of an Si-OH peak ((3,788 ± 50) cm−1
Implementation Method 2
FAU zeolite is known as a CO2 adsorbent material
Data Source
Figure 1(a)~1(b)
Figure 2~3
Figure 4~5
AI summary
An adsorbent having a core-shell structure, wherein the core is composed of a zeolite, and the shell satisfies all of the following requirements (A) to (C): the shell (A) being a silicate-based oxide composed of a silicate or an aluminosilicate having an SAR of 750 or more; (B) having a zeolite structure; and (C) having a ratio (ISi-OH/ISi-O) of a peak intensity ISi-OH of an Si-OH peak ((3,788 ± 50) cm-1) to a peak intensity ISi-O of an Si-O peak ((1,868 ± 70) cm-1) of 3.0 or less in FT-IR of the adsorbent.