The effect of carbonization heating rate on charcoal and active carbon yields

Abstract

The thermal decomposition of white oak chips was investigated by pyrolyzing 1-k samples at atmospheric pressure in an electricallyheated batch reactor using five carbonization heating rates from 0.98 to 9.44°C/min, and a maximum temperature of 490°C. The resulting charcoals were then activated with steam in a second batch reactor. Iodine number was used as a measure of the sorptive capacity of the active carbon. Charcoal yields decreased as the carbonization heating rate increased, particularly for rates less than about 4°C/min. Active carbon yields decreased and iodine numbers increased as the severity of gasification increased. For carbonization heating rates greater than about 4°C/min, the active carbon yield for a given iodine number was essentially independent of the heating rate.