Investigation of combined SO{sub 2}/NO{sub x} removal by ceria sorbents. Quarterly technical progress report

Simultaneous removal of SO{sub 2} and NO{sub x} using a regenerable solid sorbent will constitute an important improvement over the use of separate processes for the removal of these two pollutants from stack gases and possibly eliminate several shortcomings of the individual SO{sub 2} and NO{sub x} removal operations. Recent studies at PETC considered cerium oxide as an alternate sorbent to CuO. The present study aims to determine the effects of ammonia on the sulfation of the sorbent and to obtain a rate expression for the regeneration of alumina-supported CeO{sub 2} sorbents. In the past quarter the effect of ammonia on sulfation was investigated. It was found that the presence of ammonia affects the sulfation process unfavorably by forming ammonium sulfate species on the surface which subsequently decompose and cause sulfur loss from the surface. Since formation of surface ammonium sulfates increase the sorbent mass, it is difficult to deduce the magnitude of the sulfur loss from the surface only by thermogravimetric analysis