The report gives results of experiments in a boiler simulator furnace, indicating that the parameters of major importance to SO2 capture are thermal environment, calcium/sulfur ratio, and sorbent composition. Thermal environment (local temperature) had a strong effect on the utilization of dry sorbents injected directly into the furnace. Burner staged experiments showed the influence of temperature most clearly: a reduction in peak flame temperature, due to either cooling in the radiant zone or a reduction in load, increased sulfur capture significantly. Changes in other combustion parameters (e.g., sorbent location and injection velocity) had secondary effects on sulfur capture. The influence of sorbent type (Vicron 45-3, Vicron 15-15, Michigan marl, hydrated lime--Ca(OH)2, and dolomite) on sulfur capture was studied at five different combustion conditions: Indiana No. 3 coal fired in the distributed mixing burner with and without external cooling, Indiana No. 3 coal under externally staged conditions, and propane doped with H2S. In general, dolomite gave good capture under all conditions. Hydrated lime appeared to be most sensitive to thermal environment, and dolomite was least sensitive. High captures were observed for all sorbents when the primary fuel was propane/H2S.

"EPA Contract No. 68-02-2667." "June 1985." "EPA/600/7-85/025." "Final report period June 1980 - June 1983." Microfiche.