Kinetic properties of the components of Douglas-fir and the heat of combustion of their volatile pyrolysis products

Abstract

Specimens of the chemical components of Douglas-fir, which include cellulose, lignin, mannan, and xylan, were pyrolyzed in nitrogen in the temperature range between 290 and 370 C, which is characteristic of the pyrolysis temperature range of wood in a fire environment. From these data, the effective activation energy, preexponential factor, and the net heat of combustion of the volatiles were calculated as a function of the mass retention fraction of the specimen. These kinetic parameters were used to calculate the mass loss rate of Douglas-fir and a prepared mixture of the components in a pyrolyzer based on their measured temperature histories. The calculated mass loss rates were within a factor of two of the measured values.