MIXED WASTE FERRITE AS A NOVEL SORBENT FOR CARBON-DIOXIDE DERIVED FROM FLUE-GASES

Ferrite is a potential sorbent for flue gases such as CO2, H2S and SO2 . This paper discusses the adsorption and decomposition of CO2 into ca rbon by hydrogen-activated waste ferrites prepared from Berkeley Pit a cid mine water (Butte, MT). The decomposition effectiveness of these w aste ferrites was studied at 300 degrees C and compared with the synth etic magnetite obtained from ferrous sulfate solution in our laborator y. The decomposition was measured by two methods: indirectly by measur ing the adsorption rate of CO2 and directly by analysing the carbon de posited on the samples. The results indicated that the mixed waste fer rite had good affinity for the adsorption and decomposition. The CO2 d ecomposition data of both sorbents fitted the first-order reaction kin etics. Even though the surface area of the magnetite was higher than t hat of waste ferrite, the CO2 decomposition rate of the waste ferrite was estimated to be 2.5 times higher than that of magnetite under iden tical conditions. The carbon analysis deposited on the sample indicate d that the CO2 was 100% decomposed into carbon and other carbon/hydrog en compounds by the waste ferrite, whereas the conversion was 43% by t he magnetite. In terms of specific adsorption of carbon, ferrite was t hree to five times more efficient than magnetite.