Reaction Behavior of Sulfur Dioxide with Ammonia

To understand the sulfur recovery behavior during regeneration of SO 2 -adsorbed sorbents in NH 3, the reactions of SO 2 −NH 3 −H 2 O in the absence of O 2 are studied in a temperature range of 10−80 °C and feed NH 3 /SO 2 molar ratios of 1−3. The solid products are analyzed by thermal gravimetric analysis, the element analysis, and the wet chemical analysis. The results show that the reactions are very fast and the products are mixtures of various types of ammonium−sulfites with (NH 4 ) 2 SO 3 as the main component. A lower temperature, a greater NH 3 /SO 2 molar ratio, and a higher water vapor content favor the SO 2 conversion to the sulfites. The amount of the sulfites collected and their composition are correlated to temperature and the feed NH 3 /SO 2 molar ratios.