Comparison of adsorption related properties of Zonguldak Basin coals (NW Turkey) obtained at two different adsorption temperatures of carbon dioxide

Abstract

Adsorption related properties of seven coal samples from Zonguldak Basin in northwestern Turkey were determined using the low-pressure CO2 method at two different adsorption temperatures of CO2, namely at 195degreesK and at 273degreesK. By application of the Dubinin-Radushkevich approach, micropore volumes ranging between 0.02-0.05 cm(3)/g, micropore capacities ranging between 9.9-27.3 cm(3)/g, and micropore surface areas ranging between 58-160 m(2)/g at 195degreesK were determined. Respective values at 273degreesK were 0.04-0.07 cm(3)/g, 22.6-39.0 cm(3)/g and 154-265 m(2)/g. Results on diameters of pores suggest that smaller pores were intruded by CO2 at 273degreesK. Therefore, measurements at this temperature are considered to be closer to the micropore structure of Zonguldak coals. Based on the relationship obtained by comparison of the results of seven samples at 195degreesK and at 273degreesK, and using the previously determined values at 195degreesK, we have been able to re-calculate the adsorption related properties of additional 35 coal samples from Zonguldak Basin.