C3N4/6FDA-DAM Mixed Matrix CMS Membrane for Ethylene-Ethane Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current CMS materials exhibit low selectivity and flux during ethylene/ethane separation processes.
Innovation Solution
A mixed matrix CMS membrane is prepared using C3N4 nanosheets dispersed in a carbon matrix obtained through pyrolysis of 6FDA-DAM polymer, with the C3N4 nanosheets undergoing hot peeling treatment and pyrolysis, resulting in a C3N4/6FDA-DAM membrane with enhanced separation performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional CMS membranes are used for C2H4/C2H6 separation, then the separation process can be simplified with no phase transition, but the selectivity and flux are low
Solution Approach 1:
The patent uses a composite membrane structure combining PVDF polymer matrix with CMS particles (prepared from tripolycyanamide precursor). This composite structure integrates the advantages of both materials: PVDF provides mechanical strength and chemical stability, while CMS particles provide high selectivity and flux for C2H4/C2H6 separation, thereby resolving the contradiction between ease of operation and productivity
2Productivity
If absorption process is used for gas separation, then separation can be achieved based on chemical affinities, but solvent recovery requires high energy consumption
Solution Approach 1:
The patent replaces the chemical absorption process with a physical membrane separation process. Instead of using solvents that require energy-intensive recovery, the PVDF-CMS composite membrane achieves separation through physical mechanisms (size exclusion and adsorption) driven by pressure differential, eliminating the need for solvent recovery and significantly reducing energy consumption while maintaining high separation efficiency
3Quantity of substance
If low-temperature rectification process is used, then C4+, ethane, and propane can be produced and enriched, but the process involves high cost and high energy consumption
Solution Approach 1:
The patent utilizes porous PVDF-CMS composite membrane with specific pore size distribution to achieve separation of C2H4/C2H6 and other hydrocarbons. The porous structure enables selective permeation based on molecular size and adsorption characteristics, allowing production and enrichment of C4+, ethane, and propane at lower temperatures and energy consumption compared to traditional low-temperature rectification processes
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 C3N4/6FDA-DAM membrane demonstrates improved permeability coefficient and selectivity for ethylene/ethane separation, with fast pyrolysis further enhancing the separation performance by optimizing the structural compatibility and transport pathways.
Implementation Method 1
A mixed matrix CMS membrane is prepared using C3N4 nanosheets dispersed in a carbon matrix obtained through pyrolysis of 6FDA-DAM polymer
Implementation Method 2
A gas separation membrane technology achieves the separation of two different gases with a pressure gradient as a driving force
Implementation Method 3
In dense membrane materials, a gas transfer is based on a dissolution-diffusion mechanism
Implementation Method 4
The PSA process is based on the ability of an adsorbent (such as a molecular sieve) to adsorb a gas at a high gas-phase partial pressure
Data Source
AI summary
The present disclosure relates to a mixed matrix carbon molecular sieve (CMS) membrane, a preparation method of the mixed matrix CMS membrane, and use of the mixed matrix CMS membrane in C2H4/C2H6 separation, and belongs to the technical field of membrane separation. The present disclosure solves the problem that the CMS materials in the prior art exhibit low selectivity and low flux during an ethylene/ethane separation process. In this patent, C3N4 is used as a filling particle to prepare a mixed matrix membrane (MMM), and the MMM is pyrolyzed to prepare a CMS membrane. The C3N4/6FDA-DAM MMM has prominent C2 separation performance.