Pore-Free Membrane for Alcohol Separation
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Solution Overview
Problem
Existing membranes for separating simple alcohols from organic mixtures are unreliable at high temperatures and in the presence of water, as they tend to swell and degrade, limiting their selectivity and stability.
Innovation Solution
A membrane with a pore-free separating layer composed of a polymer mixture, including polyvinyl alcohol and poly-N-N-dimethylaminoethyl methacrylate, applied to a porous substructure with an asymmetrical pore structure, which is then heat-treated to create a dense, stable film for effective pervaporation or vapor permeation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional membranes are used for separating simple alcohols from organic mixtures, then separation can be achieved, but the membranes swell and degrade at high temperatures and in the presence of water, reducing reliability
Solution Approach 1:
The patent uses a composite polymer system consisting of PVA combined with either polyacrylic acid or poly-N-N-dimethylaminoethyl methacrylate. This composite structure allows the membrane to maintain stability at high temperatures and in aqueous environments while preserving alcohol separation performance. The complementary properties of the polymer components create a more robust membrane system that resists swelling and degradation.
Solution Approach 2:
The patent modifies the chemical composition parameters of the separating layer by incorporating specific polymer ratios and crosslinking densities. By adjusting the composition of the polymer mixture and the degree of crosslinking, the membrane achieves optimal stability at elevated temperatures and in the presence of water, resolving the contradiction between reliability and temperature resistance.
2Stability of the object's composition
If cross-linked PVA is used as the separating layer, then thermal stability and chemical resistance are improved, but the membrane still swells in organic solvents
Solution Approach 1:
The patent combines PVA with polyacrylic acid or poly-N-N-dimethylaminoethyl methacrylate to create a composite polymer system. This composite structure provides both thermal stability and resistance to organic solvent swelling, as the different polymer components interact to create a more rigid and chemically resistant network that maintains its integrity in diverse solvent environments.
3Strength
If a porous backing layer is used to support the separating layer, then mechanical strength is improved, but mass transfer resistance increases
Solution Approach 1:
The patent applies the local quality principle by creating an asymmetric membrane structure where the separating layer has a dense, non-porous structure optimized for selective mass transfer, while the backing layer has a porous structure optimized for mechanical support. This spatial differentiation of structure and function allows the membrane to achieve both high mechanical strength and low mass transfer resistance, as each layer performs its specialized function without compromising the other.
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 exhibits high selectivity and flux for alcohols even at higher water concentrations and temperatures, maintaining stability and performance without swelling in organic solvents.
Implementation Method 1
for separating simple alcohols and water from their mixtures with other organic fluids by means of pervaporation or vapor permeation
Implementation Method 2
for separating simple alcohols and water from their mixtures with other organic fluids by means of pervaporation or vapor permeation
Implementation Method 3
after the application of the polymer solution, the solvent is evaporated and the membrane is subjected to a heat treatment
Data Source
AI summary
The invention relates to a membrane having a pore-free separation layer comprising a polymer mixture for separating off simple alcohols and water from mixtures thereof with other organic fluids using pervaporation or vapour permeation. According to the invention, the polymer mixture consists of at least two polymer components which are taken from the group of polymer components which consists of the following polymer components: polyvinyl alcohol, other polymers such as poly N,N-dimethylaminoethyl methacrylate (poly-DMAEMA), a copolymer of DMAEMA and N-vinylpyrrolidone (NVP) or of DMAEMA and N-vinylcaprolactam (NVCL), a terpolymer of DMAEMA, NVP and NVCL, or of vinyl acetate-ethylene-vinyl chloride, or of vinyl chloride-ethylene-acrylic ester or of vinyl acetate-vinyl chloride-acrylic ester. In addition, the invention relates to the use and a method for production of a membrane according to the invention.