Composite Gas Separation Membrane with Zeolite and Amorphous Silica
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Solution Overview
Problem
Existing gas separation membranes, such as amorphous silica, carbon, and organic membranes, face stability issues with water vapor and combustion risks, and zeolite membranes require improved pore diameter formation for efficient hydrogen/nitrogen separation.
Innovation Solution
A composite separation structure comprising a substrate section, a first zeolite separation section, and a second amorphous silica section with controlled thickness and density, formed using a method that exposes the zeolite to Si-containing gases at 200°C or lower to enhance separation performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a polymer separation membrane is used for gas separation, then processability is excellent, but combustibility occurs making it unsuitable for separation of hydrogen and oxygen mixed gases
Solution Approach 1:
The patent uses a composite membrane structure combining inorganic porous substrate with zeolite coating layer. The inorganic substrate provides mechanical strength and chemical stability, while the zeolite coating provides separation functionality. This composite approach eliminates the combustibility issue of pure polymer membranes while maintaining separation performance.
Solution Approach 2:
The patent employs an inorganic porous substrate with controlled pore structure (0.1-10 μm) as the base material. The porous structure allows gas permeation while the inorganic material itself is non-combustible, solving the safety issue while maintaining separation function through the combined zeolite coating.
2Manufacturing precision
If a carbon membrane is used for gas separation, then separation performance is achieved, but combustibility and oxidation resistance issues prevent use with hydrogen and oxygen mixed gases
Solution Approach 1:
The patent replaces carbon membrane with inorganic porous substrate combined with zeolite coating. The inorganic substrate provides oxidation resistance and chemical stability, while zeolite coating maintains separation performance. This composite structure eliminates the oxidation vulnerability of carbon membranes.
3Reliability
If a silica membrane is used for gas separation, then water resistance is improved, but poor stability against water vapor makes it unsuitable for photocatalytic water splitting gas separation
Solution Approach 1:
The patent combines inorganic porous substrate with zeolite coating layer. The inorganic substrate provides water resistance, while zeolite coating (with crystalline structure) provides stability against water vapor. The synergistic combination solves both water resistance and water vapor stability issues simultaneously.
Solution Approach 2:
The inorganic porous substrate with controlled pore structure (0.1-10 μm) provides water resistance through its porous architecture, while the zeolite coating layer with its crystalline structure provides stability against water vapor degradation.
4Reliability
If zeolite separation membrane is used for gas separation, then water resistance and chemical resistance are excellent, but pore diameter formation needs improvement for efficient hydrogen/nitrogen separation
Solution Approach 1:
The patent applies zeolite coating specifically on the surface of inorganic porous substrate, creating a localized separation layer with controlled pore structure. This local modification allows optimization of pore diameter for hydrogen/nitrogen separation while maintaining the bulk water resistance properties of the inorganic substrate.
Solution Approach 2:
The patent controls the pore diameter of zeolite coating layer by adjusting coating conditions and zeolite synthesis parameters. The pore diameter is optimized to achieve efficient hydrogen/nitrogen separation while maintaining water resistance, representing precise parameter optimization.
5Manufacturing precision
If conventional zeolite separation membrane is used, then separation performance is achieved, but requires high temperature treatment above 200°C which may affect membrane stability
Solution Approach 1:
The patent modifies the zeolite coating formation process to occur at temperatures of 200°C or lower by adjusting synthesis conditions, precursor composition, and treatment parameters. This parameter change enables separation performance achievement without requiring high temperature treatment that could compromise membrane 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 composite structure achieves high separability of gases with small kinetic diameters, particularly hydrogen and oxygen, with improved stability and permeation performance, even in the presence of water vapor, and high hydrogen concentration recovery rates.
Implementation Method 1
the zeolite separation membrane has crystallinity and has regular sub-nanometer pores, it results in uniform pore size, high molecular sieving effect, and excellent separation performance
Implementation Method 2
a carbon membrane and a silica membrane have been proposed as separation membranes having sub-nanometer pores to separate hydrogen from a mixed gas
Data Source
AI summary
A composite separation structure may include a substrate section, a first separation section disposed in contact with the substrate section, and a second separation section disposed not in contact with the substrate section but in contact with the first separation section. The second separation section may be amorphous and have a thickness from an end portion in contact with the first separation section to the opposite end portion of 5 nm or more and 200 nm or less. Such a composite separation structure may be capable of separating gases having various small kinetic diameters (kinetic diameters) with high separability, and particularly capable of realizing the separation or concentration of a gas mixture containing a gas having a kinetic diameter of 4 Å or less.