Evaluation of operative factors on conversion efficiency of biodiesel production from waste cooking oil

Today, the production of biodiesel from waste cooking oil due to its renewability, low cost of production and also low pollution become more popular. In this research, the factors affecting the production of biodiesel by trans-esterification method from waste cooking oil were evaluated. For this purpose, a batch reactor which equipped with a mechanical stirrer, was designed and constructed. Waste cooking oil as feedstock and methanol is used with 1:6 molar ratio in the presence of potassium hydroxide as a catalyst to 1% by weight of waste cooking oil used. In order to optimize the production process, these three parameters including rate of stirring at 3 levels (450, 550 and 650 rpm), temperature at four levels (40, 50, 60 and 70 °C) and reaction time at 6 levels (10, 20, 30, 40, 50, 60 min) were considered. The results indicated, more than 90% of ester conversion occurred in the first 30 minutes and biodiesel production increased and reached its maximum amount at stirring speed of 650 rpm and also the highest rate of esters conversion occurred at 60 ?. Thus, 60 °C for reaction temperature and 650 rpm for stirring speed at 30 min are optimum production condition in order to reach the most amount of biodiesel from waste cooking oil using a batch stirred tank reactor.