BIODIESEL EM TRATOR AGRÍCOLA: COMPORTAMENTO OPERACIONAL EM FUNÇÃO DO TIPO E PROPORÇÕES DE MISTURA NO DIESEL DE PETRÓLEO

Biodiesel can be obtained from reacting vegetable oils, animal fats or waste oil with ethanol or methanol and stands out among renewable energy sources identified as solutions to increase energy supply security and minimize potential environmental problems arising from the use of petroleum-based fuels. The aim of this study was to evaluate the consumption of fuel and opacity of smoke from farm tractors in function of the type and proportions of biodiesel blended with common diesel oil. The experiment was conducted at the Department of Agricultural Engineering, FCAVUNESP, Jaboticabal-SP, using a 4x2 TDA tractor with engine power of 80.9 kW (108 hp). The experimental design was completely randomized in a 6x3 factorial, in which the factors consisted of six proportions of biodiesel/diesel blending (B0, B5, B25, B50, B75 and B100, in which the number indicates the percentage of biodiesel blended in diesel) and two types of biodiesel (palm and castor bean). The following parameters were determined: hourly volumetric consumption (L h-1), hourly weight consumption (kg h-1), specific fuel consumption (g kW-1 h-1) and smoke opacity. The results showed that biodiesel blends at or greater than the 50% resulted in increased specific consumption, however the type of biodiesel did not affect this variable. Smoke opacity was reduced for biodiesel blends of 5% or greater, indicating that the biodiesel type also influenced this measure, where palm oil based biodiesel presented lower opacity.