An Aromatic Fluoropolymer for Hydrogen Separation from Hydrocarbons

Area of Science:

• Materials Science
• Chemical Engineering
• Polymer Science

Background:

• Plasticization is a significant challenge in membrane-based gas separation, hindering performance and longevity.
• Developing robust polymers is crucial for efficient hydrogen separation from hydrocarbon mixtures.

Purpose of the Study:

• To introduce and characterize a novel fluoropolymer, poly(trifluoro styrene) (PTFS), for hydrogen separation.
• To evaluate the gas separation performance and plasticization resistance of PTFS.

Main Methods:

• Polymer structure characterization using nuclear magnetic resonance (NMR) and positron annihilation lifetime spectroscopy (PALS).
• Gas separation performance testing for hydrogen/hydrocarbon mixtures (H2/CH4, H2/C2H6, H2/C3H8).
• Evaluation of selectivity and permeability at varying pressures to assess plasticization resistance.

Main Results:

• PTFS demonstrates superior H2/CH4 separation performance compared to existing fluorinated polymers.
• The polymer surpasses the established Robeson 1991 upper bound for gas separation.
• Stable or increasing selectivity for hydrogen over hydrocarbons was observed at higher pressures, indicating excellent plasticization resistance.

Conclusions:

• Poly(trifluoro styrene) (PTFS) is a promising material for membrane-based hydrogen separation.
• The polymer's resistance to plasticization makes it suitable for high-pressure applications.
• PTFS offers a potential solution for efficient and durable hydrogen/hydrocarbon separation.