This paper describes a theoretical and experimental study on the use of a reverse-flow cyclone for the dry scrubbing of HCl. Solid lime particles are injected at the cyclone inlet at low temperatures. The inlet gas composition varied in HCl concentration up to 550 ppmv and in water content up to 3.4 vol %. The experimental results show complete HCl removal for solid reactant feeds corresponding to 2-3 times the stoichiometric ratio and for very short residence times (0.05 s). The presence of humidity in the gas was found to be very important for obtaining high HCl removal efficiencies. Significant differences were found in the morphology of the solid products obtained with and without humidification. The experimental results were modeled by considering plug flow for the solid phase and plug flow or perfectly mixed flow for the gaseous phase. In both cases, there is good agreement with the experimental observations. The results suggest that cyclones can be effectively and economically used for acid gas cleaning purposes.