Stacked Membranes for Gas Separation Plasticization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gas separation technologies face challenges in reducing energy consumption and costs, particularly in natural gas purification, due to issues like plasticization and inefficiencies in separating carbon dioxide and hydrogen sulfide from methane, especially at high pressures.
Innovation Solution
The use of stacked membranes with a selective layer and a protecting layer, where the protecting layer enhances the performance of the selective layer by reducing plasticization and improving permeation rates, is proposed. These membranes can be made of different polymeric or inorganic materials, with the protecting layer acting as a filter to increase the concentration of impurities before they reach the selective layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a polymeric membrane with high carbon dioxide permeation rate is used, then the permeation rate is improved, but the plasticization resistance deteriorates at high pressure
Solution Approach 1:
The membrane system is divided into two separate membranes stacked together: a first membrane optimized for high CO2 permeation rate and a second membrane optimized for high CO2/CH4 selectivity and plasticization resistance. This segmentation allows each membrane to specialize in one function rather than trying to optimize both simultaneously in a single membrane.
Solution Approach 2:
The invention creates a composite membrane system by stacking two different polymeric membranes with complementary properties. The first membrane (e.g., polyetherblockamide) provides high permeation rate, while the second membrane (e.g., polysulfone or polyimide) provides high selectivity and resistance to plasticization, creating a composite system with superior overall performance.
2Manufacturing precision
If a polymeric membrane with high carbon dioxide/methane selectivity is used, then the selectivity is improved, but the carbon dioxide permeation rate deteriorates
Solution Approach 1:
The membrane system is divided into two separate membranes stacked together: a first membrane optimized for high CO2 permeation rate and a second membrane optimized for high CO2/CH4 selectivity and plasticization resistance. This segmentation allows each membrane to specialize in one function rather than trying to optimize both simultaneously in a single membrane.
3Device complexity
If conventional single membrane systems are used, then the device complexity is low, but the energy consumption increases
Solution Approach 1:
The invention merges two different membrane systems into a single stacked membrane assembly, combining the functions of high permeation rate and high selectivity in one integrated system. This merging improves separation efficiency and reduces energy consumption compared to using separate membranes in series, while maintaining relatively simple device complexity.
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 stacked membrane system achieves improved gas separation performance, reduced plasticization, and lower energy consumption, resulting in cost savings and simplified gas separation processes, maintaining selectivity and permeation rates across varying pressures.
Implementation Method 1
the stacked membrane exhibits improved permeation properties, and/or increased plasticization resistance, for example, during high pressure mixed-gas separation
Implementation Method 2
the stacked membrane exhibits improved permeation properties, and/or increased plasticization resistance, for example, during high pressure mixed-gas separation
Data Source
AI summary
A membrane system includes a first membrane and a second membrane. At a given temperature and pressure: the first membrane has a permeation rate for a first gas and a selectivity for a gas mixture comprising the first gas a second gas different from the first gas; the second membrane has a permeation rate for the first gas and a selectivity for the gas mixture; the permeation rate of the first membrane is greater than the permeation rate of the second membrane; and the selectivity of the second membrane is greater than the selectivity of the first membrane.