Experimental characterization of an Ion Transport Membrane (ITM) reactor for methane oxyfuel combustion

Abstract

Ion Transport Membranes (ITM) which conduct both electrons and oxygen ions have been investigated experimentally for oxygen separation and fuel (mostly methane) conversion purposes over the last three decades. The fuel conversion investigations typically involve converting methane to syngas or higher hydrocarbons. Over the past decade, ITMs have received considerable interest in the industry for oxygen separation and production of syngas. There is also a possibility that the future of ITM industrial use lies with clean power generation as long as stable ITMs are developed which separate oxygen from air and enable reaction of methane to produce carbon dioxide, steam, and the heat which powers turbines. This would hopefully provide CO 2 capture compatibilities at a lower financial and energetic cost than 'conventional' methods. In this thesis, an analysis of reported experimental ITM reactors is presented, with a view to understanding the processes which govern the permeation of oxygen, conversion of methane and production of desired gas species. The analysis shows that temperature and mass flow influence the oxygen permeation within the reactor. Also, the influence of fuel/0 2 ratio on fuel conversion and CO selectivity is discussed. The design and operation of a novel ITM reactor for the experimental investigation of oxygen separation and oxyfuel combustion (a relatively new ITM concept) is presented. The ITM reactor was designed with the aim of providing insight into the use of ITMs for power generation. The reactor has provisions for optical and spatial analysis. The reactor was used to conduct experiments using a La0.9Ca0.1FeO3-[delta] (LCF) membrane. The results of experiments conducted are presented to show the effects of temperature, mass transfer, and fuel on oxygen permeation, fuel conversion and species selectivity. A comparison is made between the observed results and reported values in literature.