Sulfation of Potassium Chloride at Combustion Conditions

The sulfation of KCl was studied in the gas and molten phase in a laminar entrained-flow reactor. The experiments were performed at 900−1100 °C with residence times of 0.24−1.22 s. Small, 65−125 micron particles of KCl were partially vaporized in the reactor and allowed to react with SO 2, oxygen, and water vapor. The conversions of KCl to K 2 SO 4 were measured in the products from both the vapor and the molten phase. The sulfation was significantly faster in the vapor phase: up to 100% conversion was obtained in the vapor phase under most conditions but only 0.5−2% conversion in the melt. The sulfation rates both in the vapor and molten phases depend on SO 2 and O 2 but not on H 2 O concentration. The results suggest that SO 3 is formed in the gas phase, and that the sulfation rate depends on the availability of SO 3 . In the gas phase, the sulfation proceeds to the extent that SO 3 is available. In the molten phase the sulfation rate was finite even in the presence of excess SO 3 .