Improving the removal efficiency of sulfuric acid droplets from flue gas using heterogeneous vapor condensation in a limestone‐gypsum desulfurization process

Abstract

ABSTRACT BACKGROUND Emissions of sulfuric acid droplets have caused many problems. Improving the removal efficiency of sulfuric acid droplets is of great importance. A novel process based on heterogeneous vapor condensation was proposed in this paper to improve the removal efficiency of sulfuric acid droplets in a limestone–gypsum desulfurization process. RESULTS The results indicated that the sulfuric acid droplets were relatively easily activated in a supersaturated vapor environment and condensed into larger droplets. The removal efficiency of sulfuric acid droplets in a wet flue gas desulfurization ( WFGD ) system could be significantly improved. The improvements were mainly related to the inlet flue gas moisture content and temperature. A relatively higher moisture content and lower temperature of inlet flue gas improved the removal performance. Moreover, the liquid‐to‐gas ratio and the SO 3 concentration also contributed to the improvement in removal efficiency. However, a higher temperature of the desulfurization slurry was unfavorable. CONCLUSION The novel process based on heterogeneous vapor condensation is suitable for industrial application. The removal efficiency of sulfuric acid droplets can be improved from 30 ∼ 40% to greater than 60%. © 2016 Society of Chemical Industry