Crosslinked PEG Membrane for CO2 Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current polymer membranes used for gas separation, such as those made from cellulose acetate and polyether block amide, face challenges including low CO2 permeability, low selectivity for H2S/CH4, and susceptibility to plasticization and swelling in high-pressure gas streams, which limits their industrial applicability and requires complex synthetic processes involving high temperatures and solvents.
Innovation Solution
A crosslinked polyethylene glycol network polymer membrane is developed, produced by reacting polyethylene glycol oligomers with methylidynetri-p-phenylene triisocyanate, which is then cast onto a filtration membrane, offering improved thermal stability, pressure stability, and selectivity for CO2 and H2S/CH4 separation without the need for catalysts or high temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional polymer membranes (cellulose acetate, polyether block amide) are used for gas separation, then thermal stability is achieved, but pressure stability deteriorates due to plasticization and swelling at high pressures
Solution Approach 1:
The patent employs a composite membrane structure consisting of a polyether block amide layer combined with a crosslinked polyethylene glycol network polymer layer. This composite approach allows the polyether block amide to provide thermal stability while the crosslinked PEG network resists plasticization and swelling at high pressures, thus simultaneously achieving both thermal stability and pressure stability.
Solution Approach 2:
The patent modifies the chemical structure and crosslinking density of the polyethylene glycol network polymer to optimize its resistance to plasticization. By adjusting the crosslinking degree and molecular weight parameters, the membrane maintains its physical integrity and selectivity under high pressure conditions while retaining thermal stability.
2Manufacturing precision
If glassy polymers like cellulose acetate are used, then CO2/CH4 selectivity is improved, but H2S/CH4 mixed gas selectivity deteriorates due to plasticization
Solution Approach 1:
The composite membrane combines cellulose acetate or polyether block amide with crosslinked polyethylene glycol network polymer. The crosslinked PEG layer provides resistance to plasticization by H2S, maintaining H2S/CH4 selectivity, while the base polymer maintains CO2/CH4 selectivity performance.
Solution Approach 2:
The membrane is designed with different functional layers: one layer optimized for CO2/CH4 separation and another crosslinked PEG layer specifically designed to resist H2S-induced plasticization. Each layer performs its specialized function, achieving both selectivity requirements simultaneously.
3Productivity
If conventional membranes are used to achieve adequate permeability, then gas flow is improved, but selectivity deteriorates due to plasticization effects
Solution Approach 1:
The composite structure allows the membrane to achieve high gas permeability through the polyether block amide or cellulose acetate layer, while the crosslinked PEG network layer maintains selectivity by preventing plasticization-induced degradation of separation performance.
4Ease of manufacture
If conventional synthetic processes are used, then membrane production is achieved, but process complexity increases due to high temperatures, catalysts, and solvents
Solution Approach 1:
The crosslinking process is conducted at moderate temperatures without requiring high-temperature processing, catalysts, or extensive solvent systems. This simplification of process parameters reduces equipment requirements and operational complexity while maintaining membrane quality.
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 polymer membrane achieves enhanced CO2/CH4 selectivity and H2S/CH4 selectivity, maintaining stability and performance even at high pressures, and can be produced at moderate temperatures with minimal solvent use, addressing the limitations of existing membranes.
Implementation Method 1
polymer membranes are of great research interest in the membrane technology field... suitable intrinsic transport properties (that is, the passage of small molecules through the membrane)
Implementation Method 2
there are other significant material challenges, such as physical aging and plasticization that must be addressed... maintaining stability and performance even at high pressures
Data Source
AI summary
A polymer membrane, methods of gas separation utilizing the polymer membrane, and methods of producing the polymer membrane are disclosed herein. The polymer membrane includes a crosslinked polyethylene glycol network polymer according to formula (I):