Experimental Study of Chemical Absorption of CO2 in a Bench-Scale Spray Dryer Absorber

The removal of CO2 through chemical absorption in a bench-scale spray dryer absorber was investigated experimentally using the lime slurry as absorbent. The effect of important operating parameters on CO2 removal efficiency has been investigated; in selected ranges of operating parameters, increasing gas inlet temperature and absorbent concentration lead to permanent efficiency decline, increasing liquid to gas flow rate ratio and inlet gas humidity and lowering CO2 concentration have favored the removal efficiency. Adding Na (OH) solution to the absorbent increases its ability to absorb CO2 whiles decreases its tendency to produce final dried powder. It was found that adding 100 mL of Na (OH) solution with 1 mol/L concentration per each 1000 mL of lime slurry gives a removal efficiency of 70.5%. Other operating parameters were according to the following: Tg,in = 200 °C, CA,in = 5 %(vol.), CB,in = 0.7 mol/L, (L/G)in = 0.025 mL/L, Hin=0.024 kg/kg and N=12600 rpm.