Process configurations/modeling -- Project 3.1. Final report, September 1, 1992November 30, 1993

Abstract

The objective of this research is to develop and optimize preliminary process designs and cost estimates for a moving bed granular limestone desulfurization process typified by the LEC (Limestone Emission Control) process. The basic simulation programs have been written, debugged, and used to simulate the operation of a desulfurization plant with a cross flow moving bed configuration. The programs are based on first principles type mathematical models which reflect the underlying transport and chemical reactions which are involved in the desulfurization process. Spatial and temporal variations in component concentrations and temperature are considered. The simulation program centers around a resistance in series model which is used to calculate the sulfur dioxide transport rate. Resistances include mass transfer from the bulk gas to the condensed liquid surface, diffusion of sulfate and calcium ions in the liquid layer, and dissolution of calcium ions from the limestone surface. Sorbent blinding due to the formation of a precipitative layer and dry capture have also been incorporated into the model.