Optimization of biodiesel production from grape kernel oil using alkaline catalysts and study of its physical properties

Biodiesel is a renewable fuel that, due to increasing environmental pollution, global warming caused by fossil fuels and limited fossil fuel resources, its production is increased. Different resources are for production of biodiesel such as animal fats, edible waste oil and vegetable oils. In this study, grape kernel oil was used for production of biodiesel using potassium hydroxide and sodium hydroxide as catalysts and methanol. For this purpose, effect of several parameters such as temperature, reaction time, methanol to oil ratio, the amount of catalyst and type of catalyst were studied and optimal conditions for the production of biodiesel were obtained. The maximum efficiency of biodiesel production for KOH and NaOH were determined 99 and 95 %, respectively which these efficiencies were obtained in the optimum conditions such as temperature of 70 oC, 1 wt. % catalyst, 90 min and methanol to oil ratio of 9:1. For analysis of biodiesel produced in optimal conditions, the international standard ASTM D6751 and EN 14214 were used. The results showed that the properties of biodiesel using KOH such as density, viscosity, flash point, cloud point, acid number, cetane number, pour point and distillation temperature were 860 kg/m3, 3.3 mm2/s, 160oC, 1oC, 0.2, 52, -5oC and 342oC, respectively and this properties using NaOH were 870 kg/m3, 3.5 mm2/s, 172oC, 4oC, 0.15, 57, -4oC and 354oC, respectively.