Spent acid and/or hydrogen sulfide are burned at elevated temperatures to provide SO2 gas. In the case of spent acid, fuel is burned along with the spent acid in the combustion chamber to achieve the required decomposition temperature. The wet SO2 combustion gas is then cooled in a steam boiler to recover energy prior to entering the primary Dynawave Reverse Jet Scrubber. From the scrubber on, the process equipment arrangement will have some variation depending on the amount of insoluble generated in the combustion chamber.
SO3 Absorption
After passing through the first three layers of MECS LP and Cesium catalyst, SO3 rich gas is cooled and absorbed with 98% sulfuric acid (H2SO4) in the Interpass absorption tower. The lean SO2 gas flows through a Brink Mist Eliminator to remove fine mist particles, thereby protecting downstream equipment. The clean gas is then reheated and enters the converter to complete the conversion of SO2 to SO3. The SO3 formed is absorbed in 98% H2SO4 in the final absorbing tower. Brink Mist Eliminators are installed in the final tower to insure the stack gas will meet environmental regulations on acid mist.
