Preparation of Activated Carbon from Yallourn Brown Coal

Abstract

Two kinds of chars were prepared from Yallourn brown coal, in the size of 10 to 20 mesh, by carbonizing them with heating rates of 1°C/min and 40°C/min in nitrogen up to 800°C. The influence of heating rates in carbonization was investigated on the micropore-developement of the chars activated with a CO2-CO mixture (Pco2/Pco=2.3) under the conditions of reaction-rate controlling step at 800°C. The adsorption isotherms of methanol and benzene vapors on the activated samples were determined at 50°C and 45°C, respectively. The pore volume in the range of 1 to 10nm in radii and parameter W0 (micropore volume) were also estimated.As a result, it was proved that the difference of heating rates in carbonization process did not affect on the rates of activation in a CO2-CO mixture. However, the pore volume of activated samples suggested the influence of heating rates in carbonization process. That is, the pore volume and Wo of activated samples which were carbonized with heating rate of 40°C/min were greater than that of the ones carbonized with heating rate of 1°/min. It may be concluded that the much higher rate in carbonization process would be advisable to make the activated carbons of much greater pore volume and W0.