The influences of CO2 and O-2 on SO2 removal from flue gas using a powder-particle spouted bed were investigated. The experimental results showed that O-2 concentration does not affect SO2 removal from flue gas in the experimental range. The influence of CO2 on SO2 removal was found to depend on the approach to saturation temperature (DeltaT(a)), which is the difference between bed temperature and adiabatic saturation temperature. The smaller the value of DeltaT(a) was, the weaker the influence of CO2 became. Finally, when the value of DeltaT(a) was smaller than 16 K, SO2 removal was hardly affected by the presence of CO2. In addition, about 40% of the sulfate in the total of sulfite and sulfate was found in the spent SO2 sorbent, acid the mole fraction appeared to be independent of DeltaT(a) and the CO2 concentration in the flue gas. (C) 2001 Elsevier Science Ltd. All rights reserved.