SINTESIS BIODIESEL DARI MINYAK GORENG BEKAS TERADIASI MICROWAVE DAN TERKATALISIS SO4/ZrO2DAN Na2O/ZrO2; SYNTHESIS OF BIODIESEL FROM USED COOKING OIL IRRADIATED BY MICROWAVE AND CATALYZED BY SO4/ZrO2 AND Na2O/ZrO2

Niyar Candra Agustin, Karna Wijaya

2015 | Disertasi | FMIPA

Synthesis of biodiesel from used cooking oil irradiated by microwave and catalyzed by SO4/ZrO2 and Na2O/ZrO2 had been investigated. The synthesis was carried out via two steps reaction i.e. esterification using SO4/ZrO2 catalyst to reduce FFA (free fatty acid) content of used cooking oil and followed by transesterification using Na2O/ZrO2 catalyst. Preparation of SO4/ZrO2 and Na2O/ZrO2 catalyst was conducted by wet impregnation method. The SO4/ ZrO2 catalyst was prepared using ZrO2 and 0.5 M H2SO4 while Na2O/ZrO2 was prepared using ZrO2 and 2 M NaOH. The esterification and transesterification reaction were carried out with variety of microwave powers of 400, 500, 600, 700, and 800 watt with reaction time of 10 min. Character of the SO4/ZrO2 and Na2O/ZrO2 catalyst were analyzed using FT-IR spectrophotometer and XRD. Amount of Na2O loaded in ZrO2 was determined by SEM/EDX. The determination of acidity SO4/ZrO2 catalyst was carried out by gravimetric method using ammonia adsorption and the basicity of the Na2O/ZrO2 catalyst was determined by Hammet method using benzoic acid titration. Biodiesel was characterized using GC-MS, 1H-NMR spectrometer, and ASTM. The results showed that the SO4/ZrO2 and Na2O/ZrO2 catalyst have been successfully synthesized. The optimum reduction of the FFA in used cooking oil was 44,16 wt% obtained at 700 watt microwave power with reaction time of 20 min. The highest yield of biodiesel was obtained under 700 watt microwave power with 10 min reaction (66.02%). The formation of biodiesel was confirmed by the appearance of several peaks corresponding to the peak of methyl palmitate (63.44%), methyl oleate (28.56%), methyl linoleic (3.19%), methyl myristate (2.41%), and methyl stearate (2.39%). The ASTM data showed that the biodiesel product has some specification as well as those of the biodiesel standart.

Kata Kunci : Biodiesel, used cooking oil, SO4/ZrO2 catalyst, Na2O/ZrO2 catalyst, microwave