Calorific and porosity development in carbonized wood.

Abstract

Wood of four species (red oak, southern yellow pine, black cherry, and hybrid poplar) were carbonized in a flowing nitrogen atmosphere at an average heating rate of 3 degrees Centigrade/minute to selected final temperatures up to 700 degrees Centigrade. The effects of final carbonization temperature on selected properties of the char were obtained using an adiabatic oxygen bomb calorimeter to investigate heat of combustion and a mercury porosimeter to investigate total porosity, real density, apparent density, and pore size distribution. Pore characteristics of carbonized wood developed before 300 degrees Centigrade in southern yellow pine and before 400 degrees Centigrade in red oak, black cherry, and hybrid poplar. Statistical analysis established linear relationships between heat of combustion versus final carbonization temperature in the carbonization temperature ranges investigated. The results of this study will aid in understanding optimum pryrolysis conditions for the development of calorific and porosity values. (Refs. 22).