Abstract
Dry scrubbing with lime slurry in a spray dryer [spray dryer absorber (SDA)] has been an important technology for flue gas desulfurization (FGD). Mathematical models based on the heat and mass balances are used to predict SO2 removal in the SDA as a function of initial size distribution of slurry droplets. Since the existence of moisture in the droplets appreciably enhances the SO2 removal, its removal efficiency depends on the rate of drying as well as that of SO2 removal itself, both depending on droplet diameter. With the increase in the geometric standard deviation (GSD) of the initial droplet size distribution, the efficiency of SO2 removal first increases and then decreases, showing a maximum at a certain value of GSD. This trend is altered by the sorbent content of the droplets, expressed as stoichiometric ratio (SR). The decrease in SR makes the maximum move to higher GSD and reduces the variation in the efficiency with respect to GSD. For SR<0.73, a minimum efficiency also appears, ahead of the maximum. The results are well explained by the specific rates of both drying and SO2 removal of the droplets.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Jang, S. H., Oh, E. K., Lee, H. K. and Kim, S. G., “Model Development of Spray Dryer Absorber FGD Process,”Clean Technology (Korean),2, 80 (1996).
Jozewicz, W. and Rochelle, G. T., “Modeling of SO2 Removed by Spray Dryers,” Proc. First Annual Pittsburgh Coal Conf., Sept. 17–21, 663 (1984).
Klingspor, J., Karlsson, H. T. and Bjerle, I., “A Kinetic Study of the Dry SO2-Limestone Reaction at Low Temperature,”Chem. Eng. Commun.,22, 81 (1983).
Kolluri, R., Hatcher, Jr. W. J. and Jefcoat, L. A., “Simulation of Spray Drying with Reaction: Absorption of Hydrogen Sulfide in Ammoniacal Solution of Zinc Chloride,”Drying Technology,9, 367 (1991).
Partridge, G. P., Jr., “A Mechanistic Spray Dryer Mathematical Model Based on Film Theory to Predict Sulfur-Dioxide Absorption and Reaction by a Calcium Hydroxide Slurry in the Constant Rate Period,” Ph.D. Dissertation, Tennessee Univ., Knoxville, U.S.A. (1987).
Shih, H. S., “Simulation of Sulfur-Dioxide Removal via Hydrated Lime Slurries in a Spray Dryer Absorber Flue-Gas Desulfurization System,” Ph.D. Dissertation, Alabama Univ., Tuscaloosa, U.S.A. (1989).
Yuan, C. S., “Simultaneous Collection of SO2 and NOx via Spray Drying: Using Sodium Based and Calcium Based Sorbents with Select Additives,” Ph.D. Dissertation, Univ. of Illinois at Urbana-Champaign, U.S.A. (1990).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Oh, EK., Jung, GH., Kim, SG. et al. Effect of initial droplet size distribution on sulfur removal efficiency in FGD/SDA. Korean J. Chem. Eng. 16, 292–297 (1999). https://doi.org/10.1007/BF02707115
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02707115