Development of a hydrogen purifier with Pd-based composite membrane

Abstract

A hydrogen purifier equipped with Pd-Cu-Ni/PNS membranes has been developed to purify low-grade hydrogen and supply it to processes requiring high-purity hydrogen. The purifier does not include any purge system to flush out hydrogen from the membrane module to prevent membrane embrittlement because there is no α-β phase transition below the critical point of the Pd-H system, making the purifier simple. The hydrogen purifier was tested with three different grades of hydrogen, 90, 99 and 99.9%, to determine the effects of the grade of feed hydrogen on the hydrogen permeation behavior. A lower grade required a lower recovery ratio of the purifier to obtain a given relative hydrogen permeation flux. It was confirmed that the purifier can provide high-purity hydrogen to a gas chromatograph (GC) for carrier and make-up gases. A 75-day durability test provided evidence that the hydrogen purifier could be useful for extended periods as needed for commercial processes.

Development of Pd Alloy Hydrogen Separation Membranes with Dense/Porous Hybrid Structure for High Hydrogen Perm-Selectivity

“…(1) While Pd membranes easily suffer from hydrogen embrittlement due to the 𝛼-𝛽 phase transition at temperatures below the critical points of the Pd-H system [25], no 𝛼-𝛽 phase transition occurred in Pd-Cu alloy membrane [26]. Therefore, it was possible to design and build up a simple hydrogen purifier [27].…”

Ultra-thin Ni dense membrane prepared by polishing treatment of porous nickel support for high-temperature H2 separation

“…Pd and its alloys are considered suitable material for the fabrication of hydrogen separation metal membranes because of their high hydrogen permeability and chemical stability in hydrocarbon-containing gas streams [3]. Pd-based membranes already form the basis of current bench-scale purifiers and methanol reforming units [4,5]. The main drawback of Pd-based membranes is their extremely high cost for large-scale applications [6].…”