CHARACTERIZATION STUDY OF CHAR AND ACTIVATED CARBON PREPARED FROM RAWAND EXTRACTED ROCKROSE

Using raw rockrose (Cistus Ladaniferus, L.) and rockrose extracted int o petroleum ether, the effect of extraction on the thermal behaviour a nd chemical-physical properties of chars and activated products was st udied. Chars were prepared by heat treatment of the starting materials under dynamic and isothermal conditions over the temperature range 20 0-1000 degrees C. Activations of two carbonized products, which were o btained at 600 degrees C, was accomplished in air, CO2, Or steam at 85 0 degrees C until burnoff 40%. Techniques used were thermogravimetry, gas adsorption, mercury porosimetry, density measurements, and FT-IR s pectroscopy. Extraction delayed the rockrose pyrolysis, as inferred fr om the thermal behaviour of the starting materials and by the composit ion and texture of the chars prepared between 200-600 degrees C. At hi gher temperatures, extraction reduced the ash content of chars and mit igated the loss produced in the surface area and the microporosity. Di fferences in textural properties of activated carbon depended on the s tarting material and the activating agent, being especially significan t between air and CO2 or steam. The FT-IR spectra of the carbonized an d activated products displayed absorption bands compatible with the pr esence in the materials of surface olefinic C=C double bonds, aromatic rings, and oxygen functional groups.