Empirical model of slow pyrolysis of hardwood chips

Abstract

The thermal decomposition of mixed hardwood chips was investigated by pyrolyzing 1-kg samples at atmospheric pressure in an electrically-heated batch reactor. The maximum temperature was varied from 464 to 871 °C. Yields of charcoal, light oil, heavy oil, water, and gas were determined. The heating value and moisture content were determined for the feed, charcoal, light oil, and heavy oil. Gas chromatography was used to determine the composition of the gas product. Using these data, an empirical model was developed to predict the yields of charcoal, dry light oil, dry heavy oil, water of pyrolysis, C2–C5 hydrocarbons, light organics, and permanent gases—carbon dioxide, carbon monoxide, hydrogen, and methane—in terms of the maximum temperature to which the charcoal was heated.