Energy balance in sawing Eucalyptus grandis logs

Abstract

The potential energy balance of the sawing logs for Eucalyptus lumber production was determined. Eucalyptus grandis logs (n = 10) were sawn with a band saw, and the planks were re-sawed with a circular saw. The sawing yield was calculated with the volumes of logs, lumbers, and wastes. The consumption of electric energy was measured using a multifunctional meter. The energy stored in the wood was determined by the lower calorific value of wood; the superior calorific value was calculated and converted into the respective active energy (kWh) value. The potential energy balance was calculated using the values of the consumed electricity in the saws and that of the energy stored in the waste. Another energy balance was calculated by considering the energy stored in the timber. The potential energy balance for sawing 1 m³ of log was equal to 1,206 kWh, considering only the energy stored in the waste. When added to energy stored in the timber, the energy balance was 2,671 kWh. The positive results of energy balances demonstrate the potential of energetic self-sufficiency of timber production.