Boron Nitride Membranes with a Distinct Nanoconfinement Effect for Efficient Ethylene/Ethane Separation

Area of Science:

• Materials Science
• Chemical Engineering
• Nanotechnology

Background:

• Ethylene and ethane separation is crucial for petrochemical industries.
• Existing separation methods often face challenges with efficiency and selectivity.
• Developing advanced membrane materials is key to improving gas separation processes.

Purpose of the Study:

• To develop a boron nitride (BN) membrane with enhanced nanoconfinement for efficient ethylene/ethane separation.
• To tailor nanochannels using reactive ionic liquids (RILs) for improved separation performance.
• To evaluate the separation performance and long-term stability of the developed BN membrane.

Main Methods:

• Fabrication of a BN membrane through horizontal and inclined self-assembly of 2D BN nanosheets.
• Decoration of BN nanochannels with reactive ionic liquids (RILs) to create a nanoconfinement effect.
• Characterization of membrane structure and evaluation of ethylene/ethane separation performance via gas permeation tests.

Main Results:

• The BN membrane exhibited abundant percolating nanochannels with tailored sizes due to RIL decoration.
• Noncovalent interactions between RIL and BN nanosheets led to ordered alignment within nanochannels, facilitating fast and selective ethylene transport.
• Achieved unprecedented separation performance with C2H4 permeance of 138 GPU and C2H4/C2H6 selectivity of 128.
• Demonstrated remarkable long-term stability over 180 hours, surpassing state-of-the-art membranes.

Conclusions:

• The developed BN membrane effectively utilizes nanoconfinement for superior ethylene/ethane separation.
• The RIL decoration strategy successfully enhances the size-tailoring and separation capabilities of BN nanochannels.
• This membrane technology offers a promising solution for industrial gas separation with high efficiency and stability.