Oxidation mechanisms of metallic carrier materials for gas separation membranes in power generation systems with carbon dioxide capture

点击翻译按钮获取中文摘要

Assuming a further decrease of nuclear power and before energy supply by extensive use of renew-able sources is available, the only available bridging technology can be provided by conventional power plants. The undesired increase in CO2 emissions can be counteracted by carbon dioxide capture and storage (CCS) technologies.The most efficient way to reach this technological goal is by introducing gas separation techniques using ceramic membrane technology. However, until now hardly any investigations have been carried out on the development of metallic support structures for the assembly of the gas separation systems. The metallic carriers must possess high corrosion resistance in service environments with varying concentrations of O2, N2, H2, H2O, CO2 and CO at temperatures up to 1000°C. The present project aims at an investigation of the fundamental aspects of the oxidation mechanism in such complex service environments. Based on the technological requirements, the alloys to be studied will be alumina forming materials, mainly on the basis of NiCrAl or NiCoCrAl alloys. The experimental methods used to study the oxidation processes in the mixed gas environments include the use of stable gaseous tracers such as 18O2, H218O, C18O2 and in-situ gas phase analysis using chromatography. Various analysis methods, especially conventional and high resolution TEM will be employed to investigate the scale formation mechanisms and microstructural changes in the bulk alloy on various length scales. Basic knowledge gained in the bilateral approach will be used to develop new and improved alloy concepts.