Gas Separation Membrane with Optimized Second Layer Thickness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gas separation membranes struggle to achieve high selective separation properties of carbon dioxide over nitrogen and sufficient carbon dioxide permeability, particularly with organosiloxane compounds.
Innovation Solution
A gas separation membrane configuration featuring a first layer with high gas permeability and a second layer with a smaller average thickness, composed of compounds that satisfy a specific separation performance parameter (ξ2 = ln(γ2N2) − ln(γ2CO2) > 0.56, calculated by the COSMO-RS method, enhancing carbon dioxide separation ability while maintaining good gas permeability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If organosiloxane compounds are used in gas separation membranes, then the membrane structure is formed, but the selective separation properties of carbon dioxide over nitrogen are insufficient
Solution Approach 1:
The patent uses composite materials by combining organosiloxane compound (1) with specific additives or modifying the molecular structure to introduce functional groups that enhance CO2 separation ability while maintaining membrane integrity and manufacturability
Solution Approach 2:
The patent changes the chemical parameters of the organosiloxane compound by controlling the ratio of specific structural units (Rs1, Rs2, Rs3) and introducing functional groups to optimize the separation performance parameter ξ, achieving ξ ≥ 0.562 without compromising ease of manufacture
2Reliability
If the second layer thickness is reduced to enhance separation performance, then carbon dioxide separation ability improves, but the layer becomes too thin for structural stability
Solution Approach 1:
The patent optimizes the thickness parameter of the second layer to be 1 nm to 100 nm, which is thin enough to provide high CO2 separation ability (ξ ≥ 0.562) but thick enough to maintain structural stability and prevent membrane failure
Solution Approach 2:
The patent applies different quality requirements to different layers: the first layer provides mechanical support and gas permeability, while the second layer is optimized for CO2 separation with specific thickness and composition, achieving local optimization of both stability and separation performance
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 membrane achieves improved selective separation properties of carbon dioxide over nitrogen and enhanced carbon dioxide permeability, outperforming known organosiloxane-based membranes, with the second layer's compound structure and thickness optimization key to these improvements.
Implementation Method 1
a gas separation membrane that separates, by selective transmission, carbon dioxide from a mixed gas containing the carbon dioxide and nitrogen
Implementation Method 2
the second layer satisfies 0.562, where an activity coefficient of nitrogen in the second layer is γ2N2, an activity coefficient of carbon dioxide in the second layer is γ2CO2, the activity coefficients being calculated by a COSMO-RS method, and a separation performance parameter of the second layer at 25° C. is ξ2=ln(γ2N2)−ln(γ2CO2)
Implementation Method 3
a first layer, and a second layer provided at one surface of the first layer and composed of a compound having carbon dioxide separation ability
Data Source
AI summary
A gas separation membrane that separates, by selective transmission, carbon dioxide from a mixed gas containing the carbon dioxide and nitrogen, the gas separation membrane including: a first layer; and a second layer provided at one surface of the first layer and composed of a compound having carbon dioxide separation ability, wherein an average thickness of the second layer is smaller than an average thickness of the first layer, and the second layer satisfies 0.56<ξ2, where an activity coefficient of nitrogen in the second layer, calculated by the COSMO-RS method, is γ2N2, an activity coefficient of carbon dioxide in the second layer is γ2CO2, and a separation performance parameter of the second layer at 25° C. is ξ2=ln(γ2N2)−ln(γ2CO2).