The aim of this study is to improve mixing rate of dry sorbent injection technology (DSI). A CFD (Computational Fluid Dynamics) code is used to predict the sorbent dispersion rate, pressure drop and turbulent kinetic energy of mixing particles and gas flow for three different vortex generators, which have been designed for the inside of the duct. After analyzing simulated results, it was shown that a similar trend of change in the dispersion rate in three different vortex generators had taken place and that the dispersion rate curve could reach over 80% by applying the lobed-plate and guide-vane(B) vortex generators. The lowest pressure drop was obtained when a lobed-plate was installed, whereas the highest pressure drop occurred when a guide-vane(A) was installed. The turbulent kinetic energy is nearly always stable when a lobed-plate is applied, but increases very quickly after passing through a guide-vane and then slowly decreases when a guide-vane(B) is applied. The situation for in the case of guide-vane(A) is somewhat more complicated.