PHYSICAL PROPERTIES OF EUCALYPTUS WOOD CHARCOAL

Abstract

The high cost of importing and transporting coal as well as recent concerns over CO₂ emissions from the use of non-renewable fuels, has led the steel industry to use the charcoal from eucalyptus wood as the main bio-reducer. In this context, charcoal production has increased in recent years, and the cooling processes of carbonization kilns emerge as practices to reduce costs and increase productivity by reducing the time of the production process. In these processes, the knowledge of the physical and thermal properties of eucalyptus charcoal is of fundamental importance in the design of equipment and development of cooling technologies. However, literature about physical properties for eucalyptus wood charcoal is largely unavailable in the literature, especially the thermal and aerodynamic properties, for the same material. The aim of this study was to evaluate the physical properties of eucalyptus charcoal: apparent and bulk density, pressure drop, porosity, thermal conductivity and specific heat to support the design of production and cooling systems using heat exchangers. It was found that the pressure drop could be expressed according Forchheimer’s law and logarithmical empirical models, resulting in R² above 0.95. The apparent and bulk densities were measured as 344.6 ± 17.6 and 155.3 ± 4.1 kg m^-3, respectively, and the charcoal porosity was 54.8 ± 2%. The thermal conductivity and specific heat were 0.030 ± 0.0027 W m^-1 K^-1 and 1017 ± 74 J kg^-1 K^-1, respectively.