BIODIESEL FROM LOW GRADE USED FRYING OIL USING ESTERIFICATION TRANSESTERIFICATION PROCESS

The aim of this research was to obtain the optimal condition for the production of biodiesel from low grade used frying oil through the esterification transesterification process. The experiment was arranged in Completely Randomized Design with Duncan's advanced test. Results showed that the biodiesel FFA content is ranged between 0.167 to 0.795% (P<0.01) from the 0.5 to 3.06% initial rate, with the biodiesel yield between 69.7 to 94.2%. The esterification-transesterification stage were evidently able to increase the quantity and quality of biodiesel from used frying oil. By esterification, the yield increased and the FFA content reduced. Transesterification with 6:1 methanol molar ratio and 1.5% catalyst could increase the yield up to 9.9%. The testing of four biodiesel property parameters showed that biodiesel from used oil of tofu and chips factories, and chicken fast food 1 and 2 that had been esterified met the requirements of the Indonesian National Standard (INS) 04-7182:2006 for biodiesel. Whereas directly processed biodiesel (without esterification) from used oil of chicken fast food 1 known in terms of its acid number, did not meet the requirements.