The effect of temperature and compression during pyrolysis on the density of charcoal made from Australian eucalypt wood

In this work the density of charcoal has been increased through compression of Blackbutt wood chips during pyrolysis. The true density of charcoal prepared under compression of 0.5 MPa and at a heating rate of 2 °C/min was found to increase with pyrolysis temperature, especially at temperatures higher than 450 °C. This increase in true density is likely to be due to restructuring of the graphitic structure at high temperatures. The true density of charcoal was found to be independent of compressive pressure during pyrolysis (0.056-4.0 MPa). The porosity of charcoal increased linearly with pyrolysis temperature and ranged from 0.24 at 300 °C to about 0.46 at 700 °C. The apparent density of charcoal prepared under a compressive pressure of 0.5 MPa was about 1000 kg/m3 and had minimum between 400 and 600 °C. This is similar to the apparent density of metallurgical coke. The results suggest that specially prepared charcoal could be a viable substitute for coal and coke in steelmaking applications which require a dense carbon product.