EFFECT OF HEATING RATES ON MASS LOSS AND PROPERTIES OF CHARCOAL OBTAINED FROM PYROLYSIS OF RED GUM WOOD

Abstract

This research was carried out to evaluate of heating rates on mass loss and properties of charcoal obtained from pyrolysis of red gum wood (Eucalyptus camaldulensis, Dehn.) in an electrical furnace. Ten trees with diameters of 15-20 cm were selected from the FIO eucalypt plantation, 2x8 m² spacing, in Prachinburi Province. The trees were uniformly machined into 3x3x4x cm³ specimens which were subsequently air dried. Two hundred specimens were randomly selected for the determination for effects of heating rates on pyrolysis. The study of effects of heating rates on pyrolysis of the red gum wood was carried out by heating oven dried specimens from 100° C to maximum temperature (300-550° C) at every 50° C interval. Five heating rates were given at 1, 5, 10 and 20° C/min and at maximum temperatures (isothermal). The results indicated that both maximum temperature and heating rates affected mass loss and charcoal properties. At every interval of increasing maximum temperatures, the residual mass was reduced significantly and some charcoal properties were improved, i.e. fixed carbon and heat contents. The heating rates had less effect on mass loss and charcoal properties than maximum temperatures. The residual mass was significantly remained more only at 1° C/min and maximum temperatures of 300-400° C than others heating rates. The heating rates did not affect charcoal properties significantly. The average residual mass and respective charcoal properties were listed as follows: 25.54-55.64% mass, 0.27-0.46 g/cm³ apparent density, 2.57-21.20% longitudinal shrinkage, 0.35-0.95% ash content, 16.32-48.32% volatile matter, 51.33-82.84% fixed carbon content and 6,143-7,859 cal/g heat of combustion.