This study experimentally investigated simultaneous absorption of CO2 and SO2 by NaOH solution in a powder particle spouted bed (PPSB) reactor. The Taguchi method was used for design of the experiments on the effect of the operating parameters of molar ratio of sorbent to CO2, inlet gas temperature and flow rate, and CO2 and SO2 concentrations in the gas stream on removal of CO2. In a PPSB reactor, when there is no SO2 to compete for absorption, the maximum removal efficiency of CO2 by NaOH solution was 56%; in the presence of SO2, the average removal efficiency was less than 37%. Although the CO2 and SO2 concentrations and inlet gas flow had significant effects on CO2 removal, inlet gas temperature and the molar ratio of sorbent to CO2 had little effect on removal efficiency.