Bench-scale and pilot-scale experiments have been conducted to measure the mass transfer and kinetic rates at simulated duct injection conditions. Section 2 describes the tank reactor test results. The stirred tank reactor was used to study absorption of SO{sub 2} into saturated Ca(OH){sub 2} solutions with varied ionic strengths. The results of current experiments were compared with previous tests using saturated Ca(OH){sub 2} solution and 0.1 M CaCl{sub 2}. Section 3 summarizes the status of the Short-Time Differential Reactor (STDR) tests for Task 2.3. The effect of CO{sub 2} on reactivity of Mississippi Ca(OH){sub 2} with SO{sub 2} was investigated. The extent of carbonation was measured for a commercial Mississippi Ca(OH){sub 2} and laboratory-produced sorbents. Section 4 presents pilot plant testing conducted to evaluate various operating conditions and process schemes to support large-scale field testing at Meredosia and Beverly (Task 3). Consistent data were obtained from pilot testing of in-duct dry injection downstream of the humidifier. Section 5 reports differential reactor (Task 4) tests. The differential reactor has been modified to determine the effect of initial water content on the sorbent reactivity. An experimental method has been developed to prepare solid samples containing reproducible, predictable quantities of water. The experiments …