Low temperature removal of SO2 traces from air by MgO-loaded porous carbons

Porous carbons loaded with MgO, prepared through one-step process from mixtures of poly(ethylene terephthalate) and natural magnesite, were examined as sorbents for SO2 gas contained in air at low temperature. Influence of pore structure, inorganics loading, humidity, and temperature, on the efficiency of the gas removal is presented and discussed. Performance of the hybrid sorbent materials increased along with MgO loading, temperature of the bed, and moisture content. As found, removal of SO2 by the prepared sorbents is due to synergic effect involving adsorption on porous material and chemical interaction between the gas and MgO. Possible mechanism of the SO2 removal process is proposed on the basis of XPS spectroscopy measurements.

► Poly(ethylene terephthalate) heated with magnesite gives porous carbon loaded with MgO.
► MgO-loaded carbon removes SO2 from air at low temperature.
► MgO-loaded porous carbon captures SO2 more efficiently than MgO alone.
► Physisorption and chemisorption play a role during SO2 capturing.