摘要:The storage stability is the fuel ability to resist to the chemical changes that occur during long storage periods. The contact with air (oxidative stability) and the water contact (the hydrolytic stability) are responsible for a change in storage stability. Oxidation is generally accompanied by an increase of acidity and viscosity values with a direct effect on the gaseous emissions. The gaseous emissions (CO, CO2, hydrocarbons, O2) discharged by burning of samples in a monocycle diesel fuel R Y50 were determined using a device COSTECH ECS 4010-CHNS-O. They had lower values for biodiesel samples containing 500 ppm water / kg biodiesel. Acidity determined for samples stored for 12 months at an average temperature of 22.5°C which water content were about 500 ppm respectively 2000 ppm shown an increase from 0.55 mg KOH/g to 1.02 mg KOH/g fuel. The oxidation stability of the samples determined by the method Hadorn-Zurcher was about 6,5h for the biodiesel samples containing 500 ppm and 4.3h for the biodiesel samples containing 2000 ppm water. The chromatographic analysis reveals significant compositional changes in the samples of biodiesel whose water content were about 2000 ppm/kg biodiesel compared to samples containing 500 ppm/kg biodiesel