Zeolite Membrane Thickness Control via Segmented Hydrothermal Synthesis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for forming zeolite membranes result in variations in membrane thickness due to differences in seed crystal deposition and substrate pore radii, leading to inconsistent separation factors and potential cracking issues.
Innovation Solution
A method involving multiple repetitions of hydrothermal synthesis to form zeolite membranes on a porous substrate, with a specific formula (N1/N0 + 0.1 ≤ T2~n/T1 ≤ 2N1/N0 + 2) to control the thickness and permeation rate, ensuring consistent membrane formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single hydrothermal synthesis is performed to form a zeolite membrane, then the process is simple and fast, but the membrane thickness varies due to differences in seed crystal deposition and substrate pore radii
Solution Approach 1:
The single hydrothermal synthesis process is segmented into multiple sequential syntheses. The invention divides the membrane formation into multiple stages where a first zeolite membrane is formed, then a second zeolite membrane is formed on top of it. This segmentation allows control over the thickness of each individual membrane layer, thereby achieving uniform overall thickness while managing the complexity through structured process division.
Solution Approach 2:
The invention performs preliminary actions by forming a first zeolite membrane with a controlled thickness before forming the second zeolite membrane. The first membrane serves as a foundation that establishes a baseline thickness, and the second membrane is then formed to achieve the desired final thickness. This preliminary formation allows for better control over the overall membrane thickness uniformity.
2Reliability
If the zeolite membrane is made thick to improve separation factor, then separation performance increases, but cracks are more likely to occur
Solution Approach 1:
The membrane is segmented into multiple thin layers instead of forming a single thick membrane. The first zeolite membrane and second zeolite membrane are formed as separate layers with controlled thicknesses. This segmentation reduces the stress concentration that would occur in a single thick membrane, thereby preventing cracks while maintaining the necessary separation factor through the cumulative effect of multiple layers.
Solution Approach 2:
The invention changes the parameter of membrane formation by performing multiple hydrothermal syntheses with controlled time intervals. By adjusting the synthesis time for each layer (T1 for the first membrane and T2~n for subsequent membranes), the thickness of each layer is controlled to be within a safe range that prevents cracking, while the total thickness achieves the desired separation performance.
3Strength
If the zeolite membrane is made thin to prevent cracking, then membrane strength improves, but separation factor decreases
Solution Approach 1:
The invention segments the membrane formation into multiple layers, where each layer is thin enough to prevent cracking individually. The first zeolite membrane and second zeolite membrane are each formed with controlled thicknesses that maintain structural integrity. The cumulative effect of these multiple thin layers achieves the necessary separation factor without compromising the strength of individual layers.
Solution Approach 2:
The invention creates a composite membrane structure consisting of multiple zeolite membrane layers formed sequentially. The first zeolite membrane and second zeolite membrane form a composite structure where each layer contributes to the overall separation performance. This composite approach allows the membrane to achieve high separation factors through the combined effect of multiple layers while maintaining the strength of each individual layer.
4Manufacturing precision
If multiple hydrothermal syntheses are performed to control membrane thickness, then membrane thickness uniformity improves, but synthesis time increases
Solution Approach 1:
The total synthesis time is segmented into multiple discrete synthesis periods (T1 for the first membrane and T2~n for subsequent membranes). By dividing the process into segments, the invention can control the thickness of each layer independently, achieving uniform overall thickness. The formula N1/N0+0.1≤T2~n/T1≤2N1/N0+2 provides a guideline for optimizing the time allocation between segments to balance thickness control with total process time.
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 allows for controlled thickness of zeolite membranes, preventing cracking and achieving a desired separation factor by regulating the permeation rate and synthesis time.
Implementation Method 1
forming a first to nth zeolite membrane on the surface of a porous substrate by 'n' repetitions (wherein n is an integer greater than or equal to 2) of formation of a zeolite membrane by a method of hydrothermal synthesis
Implementation Method 2
N1 denotes the permeation rate of a predetermined gas in a substrate after formation of the first zeolite membrane
Data Source
AI summary
A method of manufacturing a separation membrane structure comprising a step of forming a first to nth zeolite membranes on a surface of a porous substrate by “n” repetitions (wherein n is an integer greater than or equal to 2) of formation of a zeolite membrane by a method of hydrothermal synthesis. The following formula (1) is established in relation to the step of forming the first to the nth zeolite membranes. (Formula 1) N1/N0+0.1≤T2˜n/T1≤2N1/N0+2 (Wherein, N1 denotes a permeation rate of a predetermined gas in the substrate after formation of the first zeolite membrane, N0 denotes a permeation rate of a predetermined gas in the substrate before formation of the first zeolite membrane, T1 is a time required for formation of the first zeolite membrane, and T2˜n is a total time required for formation of the second to the nth zeolite membranes.)