Preparation of activated carbon cloths from viscous rayon. Part I. Carbonization procedures

Viscose rayon cloth was carbonized under a wide range of experimental condi tions, including heating rate, isothermal stage near the temperature of dec omposition, and preoxidation in air. Slower carbonization rates produce inc reases in yield, strength and micropore volume of the char, lower reactivit y against gasification, and micropores with narrower entrances. The inclusi on of an isothermal stage at temperatures near the beginning of the pyrolyt ic decomposition leads to a lower presence of constrictions in the char. Pr eoxidation with air produces an increase in carbonization yield and in brea king load; the presence of oxygen surface groups in the char are responsibl e for its higher reactivity to gasification. (C) 1999 Elsevier Science Ltd. All rights reserved.