On competitive uptake of SO2 and CO2 from air by porous carbon containing CaO and MgO

Porous carbon material containing CaO and MgO, prepared by carbonization of poly(ethylene terephthalate) mixed with a natural dolomite, was examined as a sorbent material for simultaneous removal of CO2 and SO2 from air in dry conditions and in a presence of humidity, at temperatures ranging from 20 °C to 70 °C. Attained results clearly confirmed crucial effect of water on amounts of gases removed from air streams and on removal mechanisms. In presence of humidity the MgO/CaO - containing carbon materials performed much more efficiently than in dry conditions. In humid conditions formation of CaCO3 was favored. In consequence amounts of SO2 captured tended to lower. Regardless of experimental conditions used for simultaneous removal of CO2 and SO2, the latter displaced certain amounts of CO2. The breakthrough curves registered clearly revealed overshoot in concentration of the gas during the first minutes of removal tests. Influence of temperature and humidity on this effect is discussed.