Silica Membrane Filter Pore Size Control for Aromatic Separation
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Solution Overview
Problem
Conventional silica membranes are ineffective in selectively separating aromatic compounds and alcohols due to their pore size characteristics, which allow substances with small molecular diameters to pass through while preventing those with larger diameters, such as aromatic compounds and alcohols, from doing so.
Innovation Solution
A silica membrane filter with a modified pore size distribution, featuring a reduced number of small pores (<0.4 nm) and an increased proportion of pores between 0.4 to 0.6 nm, supported on a porous substrate, enhances the selective separation of aromatic compounds and alcohols by allowing them to pass through while restricting larger molecules, along with the use of aryl or alkyl groups in the silica membrane to control pore formation and improve separation performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional silica membrane pore size characteristics are used, then substances with small molecular diameters can pass through easily, but aromatic compounds and alcohols with larger molecular diameters cannot pass through
Solution Approach 1:
The patent changes the pore size parameter of the silica membrane from conventional small pores to a specific range of 0.3-0.7 nm, which fundamentally alters the separation capability. This parameter change enables the membrane to selectively allow aromatic compounds and alcohols to pass through while blocking larger molecules, thus resolving the contradiction between allowing small molecules and separating aromatic compounds/alcohols.
Solution Approach 2:
The patent introduces organic groups (aryl or alkyl groups) with specific molecular diameters into the silica membrane structure. These organic groups create local regions with different pore characteristics, forming a heterogeneous structure where the overall pore size is controlled to 0.3-0.7 nm while the organic groups provide specific interaction sites that enhance the separation performance for aromatic compounds and alcohols.
2Manufacturing precision
If pore size is reduced to separate aromatic compounds and alcohols, then separation selectivity improves, but permeation flux decreases
Solution Approach 1:
The patent creates a composite silica membrane containing both inorganic silica pores and organic groups (aryl or alkyl groups). This composite structure combines the high porosity and flux characteristics of silica with the selective separation capabilities of the organic groups. The organic groups act as molecular sieves within the silica matrix, enabling high separation selectivity while maintaining high permeation flux due to the overall high porosity of the silica framework.
Solution Approach 2:
The patent optimizes the pore size parameter to a specific range of 0.3-0.7 nm, which is larger than conventional silica membrane pores but still small enough to provide high separation selectivity. This parameter change, combined with the introduction of organic groups, enables the membrane to achieve both high separation selectivity and high permeation flux by creating a dual-mechanism separation system.
3Reliability
If conventional silica membrane structure is used, then thermal resistance and chemical resistance are maintained, but separation performance for aromatic compounds and alcohols is insufficient
Solution Approach 1:
The patent combines inorganic silica with organic groups to create a composite material that leverages the advantages of both components. The inorganic silica framework provides exceptional thermal resistance and chemical resistance, while the organic groups (aryl or alkyl groups) with controlled molecular diameters provide the necessary separation performance for aromatic compounds and alcohols. This composite structure resolves the contradiction by having each component fulfill its strength.
Solution Approach 2:
The patent introduces organic groups with specific molecular diameters into the silica membrane structure, creating local regions with different properties. These organic groups are distributed within the silica matrix to form a heterogeneous structure that maintains the overall thermal and chemical stability of the silica while providing localized separation functionality for aromatic compounds and alcohols.
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 modified silica membrane filter achieves high permeation flux and selective separation of aromatic compounds and alcohols, with improved durability against water vapor and thermal resistance, effectively addressing the limitations of conventional silica membranes.
Implementation Method 1
A silica membrane filter of the present invention has performance of selectively separating an aromatic compound and performance of selectively separating an alcohol
Implementation Method 2
the pores of a silica membrane are characterized by easily passing substances having small molecular diameters (e.g., water and carbon dioxide)
Data Source
Figure 1
AI summary
There is provided a silica membrane filter having performance of selectively separating an aromatic compound and performance of selectively separating an alcohol. The silica membrane filter is provided with a porous substrate and a silica membrane. The ratio of a He gas permeation amount to an N2 gas permeation amount (He gas permeation amount / N2 gas permeation amount) is 7 or less, and the ratio of the N2 gas permeation amount to a SF6 gas permeation amount (N2 gas permeation amount / SF6 gas permeation amount) is 1.5 or more.