Hydrogen Purification Methods

Hydrogen Generators that are utilised to provide Carrier Gas for GC and GC/MS applications employ many technologies to provide high purity hydrogen. Here were look at the various methods used to purify hydrogen. Three using PEM (Proton Exchange Membrane), combined with various purification techniques, and the fourth using a combined Palladium Electrolyser.

PEM/Palladium Diffusion

Palladium membrane hydrogen purifiers operate via pressure driven diffusion across palladium membranes. Only hydrogen can diffuse through the palladium diffuser. The palladium diffuser can take a number of forms, including an array of tubes, a coiled tube or membrane foil. It comprises a palladium and silver alloy material possessing the unique property of only allowing monatomic hydrogen to pass through its crystal lattice when it is heated above nominally 300ºC. The hydrogen gas molecule coming into contact with the palladium membrane surface dissociates into monatomic hydrogen and passes through the membrane. On the other surface of the palladium membrane, the monatomic hydrogen is recombined into diatomic hydrogen.