Effects of Charring Temperature on Specific Gravity in 10 Species of Hardwood

Abstract

            The effects of charring temperature on specific gravity in wood from 10 species of Mangifera indica, Eucalyptus camaldulensis, Hevea brasiliensis, Leucaena leucocephala, Acacia auriculiformis, Tamarindus indica, Shorea siamensis, Shorea obtusa, Irvingia malayana and Rhizophora apiculata were studied. The charring temperature were 250, 300, 400, 500 and 600 degree Celsius in electric furnace.  Woods specimens were cut from 3 regions along radial position (near bark, between bark and pith, near pith). 

            The results found that R. apiculata had the highest specific gravity at 0.840 followed by I. malayana, S. obtusa, S. siamensis, T. indica , A. auriculiformis, L. leucocephala, H. brasiliensis, E. camaldulensis and M. indica with values of 0.839, 0.759, 0.736, 0.703, 0.690, 0.657, 0.636, 0.595 and 0.488,  respectively. The effects of charring temperature at 250, 300, 400, 500 and 600 degree Celsius on specific gravity in charcoal were significantly different (P ≤ 0.01) and decreased according to the increasing of charring temperature. The effects of position near bark, between bark and pith, near pith were significantly different (P ≤ 0.01) and decreased from the bark to pith except T. indica increased from the bark to pith.  The coefficient of determination of wood with charcoal under different temperature at 250, 300, 400, 500 and 600 degree Celsius were about 0.97, 0.77, 0.80, 0.81 and 0.80, respectively. This result indicated that the influence of the charring temperature to highly average specific gravity when the charring temperature raised to a contain level was constant.  The result showed that the complete charring temperature should be above 400 degree Celsius.  Therefore, it could be concluded that the requirement of good charcoal yield with high specific gravity should be conducted at charring temperature in the range of 400 to 500 degree Celsius. It was realized that the higher charring temperature be used, the less specific gravity of wood achieved.  However, high specific gravity wood could be created high specific gravity charcoal.

Keywords:  Charring Temperature, Specific Gravity, Hardwood