Study on the competitive absorption between complex components in flue gas and SO3 by alkaline absorbent

SO3 in coal-fired flue gas will cause equipment corrosion and the emission of sulfuric acid mist. The complex component in the flue gas will affect the performance of alkaline absorbent. In this study, a fixed bed reactor was used to evaluate the absorption performance of SO3 by a variety of absorbents. Then, on this basis, the competition between SO3 and SO2, SO3 and HCl were studied by the fixed bed reactor. The effect of oxygen on the competitive absorption of SO3 and SO2 by absorbents was also investigated. Further, when SO2, HCl and SO3 existed simultaneously, the competitive reactions between multiple gases were investigated. The influence of SO2 and HCl on SO3 absorption was evaluated. Carbonate absorbents had stronger absorption capacity than other absorbents. In the adsorption process of SO3 by Na2CO3, the presence of SO2 inhibited the absorption of SO3 by Na2CO3, and oxygen oxidized Na2SO3 to produce Na2SO4, which affected the reaction between SO3 and Na2CO3. There was strong competition between SO3 and SO2. In the process of SO3 adsorption by Na2CO3, the presence of HCl had an inhibitory effect on the absorption of SO3, SO3 could significantly inhibit the absorption of HCl. When SO2, HCl and SO3 existed simultaneously, SO2 had a stronger influence on the adsorption of SO3 by Na2CO3 and the presence of HCl had little inhibition on the absorption of SO3 by Na2CO3. The inhibition effect of SO2 on SO3 and the inhibition of HCl on SO3 did not accumulate.