PREPARATION OF ECONOMICAL SORBENTS FOR SO2 AND NOX REMOVAL USING COAL WASHERY REJECT

In the present study, coal washery reject, which is a solid waste material generated in coal preparation processes, is utilized to prepare carbonaceous sorbents for removal of pollutant gases SO2 and NO(x) from flue gases. The pyrolyzed char is activated with CO2 in order to improve its surface area needed for adsorption. An accelerated Surface Area and Porosimetry instrument (Micromeritics, ASAP 2000) is used to characterize the pyrolyzed and activated chars. It is found that the optimal temperature for pyrolysis is around 550-degrees-C, at which a maximum specific surface area of the char is acquired. The pyrolyzed coal reject char was then activated with carbon dioxide for various times at 900-degrees-C. A maximum surface area of the char appears as the carbon burns off in the course of reaction. The adsorption performance of the coal reject char for SO2 and NO(x) was determined using a TGA technique, and it showed that maximum adsorption capacities for SO2 and NO(x) occur at different carbon burn-offs.