FIBROUS ACTIVE CARBON DERIVED FROM PITCH

PURPOSE:To enable prepn. of fibrous active carbon suitable for adsorption of gas or liquid with controlled pore size distribution in accordance with demand by infusibilizing a fibrous material derived from pitch and carbonizing thereafter. CONSTITUTION:Pitch is heated, softened and spun to a fibrous shape, infusibilized in oxidizing atmosphere and activated then in a carbonizing furnace to obtain fibrous active carbon. In this case, the activation is performed in two stages: preactivation and post activation. Thus, fibrous active carbon having wide pore size distribution and large mean pore size is provided. In order to obtain active carbon suitable for adsorption of gas (A) and liquid (B), the pore size distribution of the fibrous active carbon is regulated to (a) 5-12Angstrom mean pore radium expressed by total pore volume/specific surface area X2 for (A), and 10-20Angstrom for (B), and (b) 0-5% ratio of pore volume of 10-20Angstrom pore radium to the total pore volume for (A), and 2-10% for (B). The convergent pore radium calculated from cumulative pore volume is regulated to below 50Angstrom .