Hydrochloric acid (HCl) is a common acidic pollutant present in the flue gas of most municipal and hazardous waste incinerators. Hydrated lime [Ca(OH)(2)] is often used as a sorbent to remove HCl through the dry and semidry scrubbing process. However, this process provides a very short residence time for the lime and HCl to react, causing the lime conversion efficiency to be low and generating a large amount of fly ash. Following our previous studies on the kinetics of the HCl-lime reaction, the current paper is aimed at the investigation of the effects of other species present in the flue gas, namely, CO2, SO2, and moisture, on the HCl-lime reaction. The reaction was carried out in a thermogravimetric analyzer at a temperature of 200 &DEG; C under 9% of O-2, and the products of the reaction were identified and quantified using X-ray diffraction. The sequential reactions of lime with CO2 (or SO2)-HCl-CO2 (or SO2) were also conducted to compare the different effects of these species on the formation of product layers. The presence Of SO2 and CO2 did not seem to affect the HCl absorption by lime on a short-time basis (< 1 min), but on a longer time basis, SO2 and CO2 lowered the conversion of lime by HCl significantly because the product from their reaction with lime strongly impeded the diffusion of the gas to the unreacted sorbent layer. The presence of HCl helped with the removal of SO2 and CO2 by lime. The presence of moisture (relative humidity 10%) in the simulated flue gas system slightly aided the conversion of lime. A better understanding of the pore blockage and the formation of the product layer on the lime surface was achieved through an in-depth discussion of the experimental results observed.