Photopolymerized Mixed Matrix Membranes for Liquid Organic Hydrogen Carrier Separation

Area of Science:

• Materials Science
• Chemical Engineering
• Sustainable Energy

Background:

• Liquid organic hydrogen carriers (LOHCs) offer infrastructure-compatible hydrogen storage and transport.
• Efficient separation of hydrogen-lean and hydrogen-rich hydrocarbons is crucial for LOHC systems but often energy-intensive.
• Membrane technology can facilitate lower-temperature dehydrogenation processes in LOHC systems.

Purpose of the Study:

• To develop novel mixed-matrix membranes for efficient separation of liquid organic hydrogen carrier components.
• To investigate the impact of photopolymerization and filler incorporation on membrane performance.
• To demonstrate a high-performance platform for LOHC separation aligned with sustainable hydrogen goals.

Main Methods:

• Fabrication of photopolymerized mixed-matrix membranes using a cyclic monomer and MOF/palladium-doped activated carbon fillers.
• In situ photopolymerization strategy to achieve high filler loadings and stratified structures.
• Characterization of membrane performance using aromatic/aliphatic selectivity and toluene/methylcyclohexane separation factors.

Main Results:

• Achieved high aromatic/aliphatic selectivities of ≈12 and a toluene/methylcyclohexane separation factor of 1.8 at 20 wt.% filler loading.
• Demonstrated high filler loadings and formation of internal polymeric dense 'skin' layers promoting selective transport.
• Presented a system with the highest performance metrics compared to early studies focusing on rejection versus mixture permeance.

Conclusions:

• The developed photopolymerized mixed-matrix membranes offer a high-performance solution for LOHC separation.
• The fabrication approach enables efficient separation, potentially lowering energy requirements for LOHC systems.
• This work contributes to advancing sustainable hydrogen production and storage technologies.