The effects of catalysts type, molar ratio, and transesterification time in producing biodiesel from beef tallow

The high level of air pollution from combustion emissions and the lack of petrodiesel feedstock sources becoming a problem that can not be ignored. Therefore, to overcome these problems researchers developed alternative fuels that are environmentally friendly such as biodiesel. Biodiesel is produced through a transesterification reaction that reacts vegetable oils or animal fats with an alcohol assisted using an alkaline or acidic catalyst. This research was conducted to find out the influence of catalyst type, molar ratio of alcohol and fat, and transesterification reaction time to the yield and the characteristics of biodiesel produced. The transesterification reaction takes place at 65°C, and the catalyst weight is 1.5% by weight of beef tallow. Variations of catalyst type are NaOH and MgO, methanol molar ratio of 6:1, 9:1, and 12:1, and transesterification time for 1 hour, 2 hours, and 3 hours. The results showed that the optimum condition of the reaction using NaOH catalyst, molar ratio 6:1, and time for 1 hour with yield value 43,64%, density 0,84392 gr/ml, viscosity 5,7057 cSt, flash point 113,5°C, calorific value 9296,9 cal/gr, acid number 0,00992, and sulfur content 39 gr/kg. (paper)