• adsorption
• alkali metals
• high temperature
• SOFC requirements

This thesis regards the removal process of alkali metals using solid sorbents at high temperature for future applications of syngas, obtained by plasma gasification of sewage sludge, in a Solide Oxide Fuel Cell (SOFC).The SOFC requires limited concentration of the contaminants and 1 ppm of alkali metals has to be achieved. Available technologies to remove alkali metals are studied and a literature review is made on solid sorbents for the removal of alkali metals at high temperature gases. The aim of this work is to further study the performance of activated alumina (Al2O3) which showed high performances to remove alkali metals from experimental results found in literature and thermodynamic equilibrium calculations. In this study is investigated the effect of temperature and moisture content on the achievable concentration and adsorption mechanism. Thermodynamic equilibrium calculations are performed in parallel with an experimental investigation. Furthermore the nature of adsorption whether physical or chemical is investigated to better understand the process and to better control alkali metal removal in future applications.