The report gives results of a study to clarify the processes that control sulfur capture by dry sorbents injected directly into a pulverized-coal-fired system, and to develop methods for generalizing data from one test furnace to another and from test facilities to fired application. Most experiments were conducted in a 1 million Btu/hr down-fired furnace to determine the effects of: fuel type, sorbent type, injection location, peak flame temperature, SO2 concentration, and burner zone stoichiometry. Conclusions of the study include: (1) the concentration of SO2 in the natural-gas-fired tests had a slight effect on sulfur capture, increasing capture at Ca/S = 2 from 26% at 500 ppm to 40% at 3500 ppm SO2; (2) the concentration of mineral matter in the system had a very strong impact on capture at all SO2 concentrations and Ca/S ratios tested; (3) injecting the sorbent downstream from the main flame resulted in improved utilization in coal flames; and (4) the effect of sorbent type on capture with a given fuel was dependent on the firing conditions--including sorbent injection location and thermal conditions (the hydrated limes seemed to be most sensitive to thermal conditions and the Vicron limestone least sensitive). Dolomite gave the highest capture with all of the fuels tested.

Caption title. "June 1985." "EPA/600/7-85/026A." Microfiche.