A simple method for producing the smokeless eucalyptus charcoal

At present, the redundant cultivation of eucalyptus wood for paper industry in Thailand causes a large amount of residue of eucalyptus wood. Beside, the business of fired food is booming. The production of smokeless charcoal is necessary done by reducing volatile content in charcoal until its content remained at least. The aim of this research was to construct the furnace and find the condition for producing smokeless eucalyptus charcoal. The furnace built from 200 litres oil tank. It consists of a burning chamber equipped with special thermal resistance cement in a thickness of 8 cm and an opening of 20x10 cm² at the bottom of furnace to get fire to eucalyptus wood. To prevent heat loss, furnace was insulated by rice husk mixed with sand. Thirty two kilograms of wood was placed into the furnace in two layers. The first layer placed fully in the vertical with furnace and the second layer locates in the horizontal direction. The procedure of controlling of furnace temperature in a range of 550˚C to 650 ˚C with a burning time of 100 min was undergone by on-off of fan and was then closed air inlet everywhere when burning finished. Undergoing with this method, it found that the mean values of temperature, true density, moisture content, volatile, fixed carbon, ash and heating value were 588˚C, 651 kg/ m³, 2.49% db, 3.82%, 88.96%, 5.04% and 31.12 MJ/kg, respectively. The remaining weight of charcoal after burning was 3.8 kg.