Partial oxidation of methane in a Zr0.84Y0.16O1.92–La0.8Sr0.2Cr0.5Fe0.5O3−δ hollow fiber membrane reactor targeting solid oxide fuel cell applications

Abstract

A membrane reactor has been investigated to reform methane into fuel suitable for solid oxide fuel cells (SOFCs). An oxygen-permeable Zr.84Y0.16O1.92 (YSZ)–La0.8Sr0.2Cr0.5Fe0.5O3−δ (LSCF) hollow fiber membrane coated with Ru catalyst at the lumen side is used to construct the reactor. The reactor is tested at elevated temperatures with the shell and lumen sides of the hollow fiber exposed to the atmosphere air and methane, respectively. The reaction of methane with the permeated oxygen proceeds at a remarkably fast rate. Methane throughput conversion over 90% is attained at 950 °C at a high methane feed rate of 14.7 cm3 CH4 min−1 cm−2 membrane surface and oxygen permeation rate 7.9 cm3 min−1 cm−2; the effluent from the reactor is composed mainly of H2 (53.5%) and CO (35.7%), revealing that the dominating reaction occurring in the reactor is partial oxidation of the methane (POM). When the effluent is fed into a disk-shaped SOFC single cell, it exhibits stable performance. The mild exothermal nature of POM reaction and the high surface to volume ratio of hollow fiber membrane may allow us to construct and operate a compact autothermal methane reformer for SOFC applications.