The Effects of H2O, CO and CO2 on the H2 Permeance and Surface Characteristics of 1 mm Thick Pd80wt%Cu Membranes

Abstract

The hydrogen permeance of 1 mm-thick Pd 80wt% Cu foils was measured in the presence of equimolar mixtures of H 2 with CO, CO 2 or H 2 O over the temperature and total pressure ranges of 623-1,173 K and 0.62-2.86 MPa, respectively. In all cases, permeance losses at 623 and 738 K were very modest. At higher temperatures, more significant decreases in membrane permeance were observed with the highest reduction of about 50% occurring when macroscopic carbon deposition occurred on the membrane surface during H 2 -CO exposure at 908 K. The more worrisome effects of exposure to these gases, however, were the micron-scale surface defects observed at 908 and 1,038 K. Although the 1 mm thick disk membranes retained their mechanical integrity, such defects could cause catastrophic failure of ultra-thin, Pd-Cu membranes (1-5 lm thick) deposited on porous substrates.

Effect of Pressure on High-Temperature Water Gas Shift Reaction in Microporous Zeolite Membrane Reactor

“…To date, literature reports on developing WGS MR have been largely concentrated on the dense Pd-alloy membranes and the amorphous silica-based microporous membranes while the WGS membrane reactions have been investigated mostly at relatively low temperatures of 200–350 °C. , The Pd-alloy membranes have perfect H 2 selectivity to produce nearly pure H 2 on the permeate side but the membranes have the long-standing issues of sulfur poisoning, hydrothermal embrittlement, and prohibitive costs. ,− The amorphous silica-based membranes also have good H 2 selectivity and high permeance but the well-known instability of these membrane materials in hydrothermal conditions still remains a challenge. − …”

High temperature hydrogenation of Ti–V alloys: The effect of cycling and carbon monoxide on the bulk and surface properties

“…Even at low interaction temperatures, CO has been shown to dissociate on a LaNi 5 surface, but at those conditions the reaction products were methane and H 2 O [30]. The effect of carbon contamination appears to be related to the gas composition and temperature, and it has been shown in previous works that gas mixtures containing carbon monoxide reduce the number of active surface sites for metalehydrogen interaction [23,24,31].…”

Hydrogen production from coal-derived syngas undergoing high-temperature water gas shift reaction in a membrane reactor

“…Based on the previously mentioned benefits, research group at the University of Pittsburgh studied the feasibility of integrating WGSR‐MR right after the gasifier. Using syngas with a temperature of 900°C, they studied the WGSR‐MR characteristics using a 100 wt% palladium (Pd) and 80%wt Pd‐20 wt% Cu shell‐and‐tube membrane reactor.…”

“…In addition to some works, [16][17][18][19][20] Li et al 21 developed a WGSR-MR using a mixed protonic-electronic conducting SrCe 0.9 Eu 0.1 O 3 − δ membrane coated onto a Ni-SrCeO 3 − δ support. The temperature range studied was from 600°C to 900°C at H 2 O/CO ratios of 1:1 and 2:1.…”