Metallic Membranes for High Temperature Hydrogen Separation

Abstract

Composite palladium membranes have extensively been studied in laboratories and, more recently, in small pilot industrial applications for the high temperature separation of hydrogen from reactant mixtures such as water‐gas shift (WGS) reaction or methane steam reforming (MSR). Composite Pd membrane fabrication methods have matured over the last decades, and the deposition of very thin films (1–5 µm) of Pd over porous ceramics or modified porous metal supports is quite common. The H 2 permeances and the selectivities achieved at 400–500 °C were in the order of 50–100 Nm 3 /m/h/bar 0.5 and greater than 1000, respectively. This chapter describes in detail composite Pd‐based membrane preparation methods, which consist of the grading of the support and the deposition of the dense metal layer, their performances, and their applications in catalytic membrane reactors (CMRs) at high temperatures (400–550 °C).

Hydrogen Production in a Large Scale Water–Gas Shift Pd-Based Catalytic Membrane Reactor

“…Mardilovich et al measured, using the mercury intrusion technique, the actual pore size for 0.2 μm grade media PSS supports, obtaining an average and a maximum pore size dimension of 2–3 μm and 6–7 μm, respectively. The grading of the two porous substrates was performed following the experimental procedures reported in detail by Guazzone and Ma and Guazzone . In particular, the membranes were graded with two coarse layers of Al 2 O 3 particles (3–5 μm in diameter), followed by two depositions of fine pre-activated particles (0.3–0.5 μm in diameter) consolidated with 10–15 min of palladium electroless plating.…”