Hydrogen-Permeable Tubular Membrane Reactor: Promoting Conversion and Product Selectivity for Non-Oxidative Activation of Methane over an Fe©SiO2 Catalyst

Abstract

Non-oxidative methane conversion over Fe©SiO₂ catalyst was studied for the first time in a hydrogen (H₂ ) permeable tubular membrane reactor. The membrane reactor is composed of a mixed ionic-electronic SrCe_0.7 Zr_0.2 Eu_0.1 O_3-δ thin film (≈20 μm) supported on the outer surface of a one-end capped porous SrCe_0.8 Zr_0.2 O_3-δ tube. Significant improvement in CH₄ conversion was achieved upon H₂ removal from the membrane reactor compared to that in a fixed-bed reactor. The Fe©SiO₂ catalyst in the H₂ permeable membrane reactor demonstrated a stable ≈30 % C₂₊ single-pass yield, with up to 30 % CH₄ conversion and 99 % selectivity to C₂ (ethylene and acetylene) and aromatic (benzene and naphthalene) products, at the tested conditions. The selectivity towards C₂ or aromatics was manipulated purposely by adding H₂ into or removing H₂ from the membrane reactor feed and permeate gas streams.

Keywords: Fe©SiO2; SrCe0.7Zr0.2Eu0.1O3−δ; membrane reactor; natural gas; non-oxidative methane conversion.