MODIFICATION OF TEXTURAL PROPERTIES OF SPANISH COAL-DERIVED CHARS BY ACTIVATION WITH CARBON-DIOXIDE

The activation of a series of chars using CO2 has been studied. As starting materials six different coals were used, ranging from high volatile bituminous to metaanthracite. The chars were prepared by pyrolysis at 1123 K in a N2 stream. Gasification was carried out in a quartz reactor, at 1123 and 1198 K, and several CO2 flows. Textural properties, such as porosity, pore size distribution, pore volume and specific surface area of the chars and the activated materials were measured. There is a relationship between the textural properties of the chars and the rank of the parent coals. The use of low CO2 flow rates had a positive influence on the pore volume and specific surface area of the activated materials. © 1990.