Sulfation of potassium chloride at combustion conditions

The sulfation of KCl was studied in the gas and molten phase in a laminar e ntrained-flow reactor. The experiments were performed at 900-1100 degrees 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 SO2, oxy gen, and water vapor. The conversions of KCl to K2SO4 were measured in the products from both the vapor and the molten phase. The sulfation was signif icantly faster in the vapor phase: up to 100% conversion was obtained in th e 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 SO2 and O-2 but not on H2O concentration. The results suggest that SO3 is formed in the gas phase, and that the sulfation rate depends on the availability of SO3. In the gas phase, the sulfation proceeds to the extent that SO3 is ava ilable. In the molten phase the sulfation rate was finite even in the prese nce of excess SO3.