Energy & Fuels, Vol.19, No.5, 1783-1789, 2005
Kinetic study of used vegetable oil to liquid fuels over sulfated zirconia
The conversion of spent vegetable oil to a synthetic chemical or direct cracking for upgrade of transport fuels are suitable ways to dispose of waste oil. This research intends to study the catalytic cracking of spent vegetable oil and thus change its classification from a waste produce to a liquid fuel as a new alternative for the replacement of petroleum fuels. This conversion was performed in a 70-cm(3) batch microreactor by varying the factors of temperature (over a range of 400-430 degrees C), reaction time (over a range of 30-90 min), and initial hydrogen pressure (over a range of 10-30 bar) over sulfated zirconia. A 2(k) factorial experimental design was used to investigate the parameters that affect the gasoline fractions. The conditions that gave the highest conversion of gasoline (similar to 24.38%) were a temperature of 430 degrees C, a reaction time of 90 min, and a hydrogen pressure of 10 bar, whereas, under the same conditions, kerosene, light gas oil, gas oil, long residues, hydrocarbon gases, and small amounts of solids were present (similar to 11.98%, 24.35%, 5.70%, 13.86%, 19.07%, and 0.65%, respectively). The kinetic study was defined to determine the reaction order and the kinetic parameters of activation energy (E-a) and the pre-exponential factor (A) from an Arrhenius relationship. The order of this reaction has been determined to be second order, and the kinetic model is defined as k(s(-1)) = 914.886 exp[-(83.439 kJ/mol)/(RT)].