Co-Solvent Tetrahydrofuran in the Production of Biodiesel From Used Cooking Oil Using the Transesterification Method

Abstract

Used cooking oil is a waste oil derived from cooking oil that has the potential to be produced into biodiesel because it contains fatty acids and triglycerides like other vegetable oils, however, its utilization is still low. This study aimed to analyze the effect of co-solvent THF based on reaction time and oil: methanol molar ratio in the manufacture of biodiesel using used cooking oil as raw material. Transesterification is a method used in biodiesel production by reacting raw materials with alcohol. KOH1% is used as a catalyst in the process of converting used cooking oil into biodiesel. In its operation, reaction time variations of 5, 7, 10, 13, and 15 minutes and molar ratios of 1:3, 1:6, 1:9, 1:12, and 1:15 were used at a temperature of 65oC. The results showed that when entering the reaction time of 10 minutes the density and viscosity tend to be stable and meet the standards of SNI 7182:2015, namely the density is stable at 0.88 gr/ml and the viscosity is in the range of 4.6238 cSt-5.7336 cSt. Meanwhile, based on the molar ratio, it was obtained only at a molar ratio of 1:6 which is in accordance with the characteristics of biodiesel based on SNI 7182:2015 which has a density of 0.88 gr/ml and a viscosity of 4.6238 cSt. The best % yield was at a 1:6 molar ratio with a reaction time of 13 minutes, that is 88.8199% with a heating value of 33.0398 MJ/kg and a cetane number of 66.9. Based on the methyl ester test with GC-MS, the methyl ester (biodiesel) content in the product was 87.24%, dominated by Oleaic (9(Z)-Octadecenoic) acid or 49.33% oleic acid and Palmitic (Hexadecanoic) acid. or palmitic acid by 34.08%.