Integrating air separation with partial oxidation of methane—A novel configuration of asymmetric tubular ceramic membrane reactor

Abstract

This paper reports a new design of ceramic asymmetric tubular reactor for correlating air separation with catalytic partial oxidation of methane (POM). The tubular membrane reactor consists of three annular layers, a porous and thin La 0.2Sr 0.8MnO 3− δ (LSM80)-Ce 0.8Gd 0.2O 2− δ (CGO20) cathodic layer, a dense and thin YSZ⊥(Pd-TiO 2) mixed conducting layer as the electrolyte layer, and a porous and thick YSZ-Ni anodic layer. For realizing mixed-conducting electrolyte layer, an electronic conductive Pd-TiO 2 stripe was wedged into a dense YSZ coating layer via a specially designed two-step calcination process. The resulting membrane reactor was assessed by its POM output in a broad temperature range as well as by its capability to clean up the coke deposited on Ni(0) catalyst. It demonstrated high methane conversion (>90%), CO selectivity (>90%) and H 2 selectivity (>80%) at 850 °C. Besides the experimental work, a mathematical model including the two major POM mechanisms responsible for the methane conversion over the temperature span of study was developed and employed to simulate the experimental X C H 4 (conversion) ∼1/ T data. The kinetic parameters obtained well accounted for the characteristics of these two reaction mechanisms.