The continuous fast pyrolysis of soybean oil in a pilot plant was investigated. The experimental runs were carried out according to an experimental design alternating the temperature (from 450 to 600 degrees C) and the concentration of water (from 0% to 10%). The liquid products were analyzed by gas chromatography and by true boiling point (TPB) distillation. A simple distillation was used to obtain purified products such as gasoline and diesel. Physical-chemical analysis showed that these biofuels are similar to fossil fuels. Mass and energy balances were carried out in order to determine the vaporization enthalpy and the reaction enthalpy for each experiment. The thermal analysis showed that it is possible to use the products as an energy source for the process. (C) 2009 Elsevier Ltd. All rights reserved.