INFILTRATION OF MICROPOROUS ACTIVATED-CHARCOAL BY PYROLYSIS OF CH4 AND ITS EFFECT ON ENHANCEMENT OF RESISTANCE AGAINST OXIDATION

Pores within activated charcoal (A.C.) were infiltrated by pyrolitic c arbon derived from thermal decomposition of CH4. The infiltrated activ ated charcoal showed an increase in resistance against oxidation with CO2. To elucidate the mechanism of this effect, the pore size distribu tion of macropores, mesopores and micropores including submicropores w ere characterized for the original A.C., infiltrated A.C., oxidized A. C. and A.C. oxidized after infiltration, respectively. It was found th at the infiltration decreased the volume and the surface area of pores , particularly the surface area of micropores. When oxidized, the carb on which deposited in macropores is almost burned but that in meso- an d micropores is only partly burned; The ratio of increase in surface a rea of the infiltrated sample is smallest for the micropores. From the se experimental results, it is deducible that the deposited carbon in micropores plays the major role for blocking CO2 intruding, thereby th e resistance against oxidation is enhanced.