Experimental and Simulation Analysis of Hydrogen Permeation Performance of Pd/Ag Permeator Used for Tritium Processing

Abstract

Since the Pd/Ag membrane has a permselectivity for hydrogen isotopes, a permeator with a Pd/Ag membrane is developed to separate tritium from inert gases. First, a permeation experiment of pure H₂ was carried out to determine the pressure exponent and the rate-determining step of permeation. It was found that the diffusion of H₂ through the Pd membrane was the rate-determining step. Then, the separation of H₂ from H₂-Ar gas mixtures was carried out on the permeator to simulate the separation of tritium. Moreover, numerical simulation was utilized to study the concentration distribution of H₂ in the permeator. The permeability of the Pd/Ag membrane was determined comparing the simulation results with the experimental data. The permeation flux of H₂ through the Pd/Ag membrane is affected by permeability, the volume fraction of Ar in the feed gas, and the flow rate of the feed gas. In the condition of high permeability and Ar volume fraction, a phenomenon known as concentration polarization occurred. It can strongly affect the permeation of H₂. Based on these results, an optimized design of the Pd/Ag permeator can be made to effectively separate tritium from other gases.

Keywords:

• Pd/Ag membrane
• permeation
• numerical simulation
• concentration polarization

Acknowledgments

This work is supported by National Natural Science Foundation of China (numbers 21601202 and 51606210).