Sintesis Metil Oleat dari Asam Oleat dan Metanol pada Variasi Rasio Molar dan Daya Microwave Menggunakan Katalis Abu Kulit Telur Ayam

Abstract

The synthesis of methyl oleate from esterification reactions between oleic acid and methanol using chicken eggshell ash catalyst using microwave. Chicken eggshell powder analyzed using Thermogravimetric Analysis (TGA), and then it was heated at 900°C for 4 hours and then analyzed using FT-IR spectrophotometer, Xray Diffraction (XRD), X-Ray Fluorescence (XRF), and Scanning Electron Microscope (SEM). The analysis results showed that chicken eggshell ash contained 99,19% CaO compounds. The reaction conditions carried out in this study were the molar ratio of oleic acid to methanol of (1:1, 1:3, 1:6, 1:9, 1:12, 1:15, 1:18) and microwave power (20P, 40P,60P,80P,100P) with catalyst weight 6% and 20 minutes reaction time in each variation. The percent conversion analyzed by using gas chromatography and FT-IR spectrophotometer. The conversion and yield of methyl oleate was obtained at 92,04% ±0,76% and 78,75% ±1,8% was obtained at ratio 1:15, a catalyst weight 6% (w/w), 20 minutes reaction time, and microwave power 60P. The analysis results of gas chromatography showed that the conversion of methyl ester reached 97,10% and analysis FT-IR spectrophotometer shows that there is absorption of -C=O stretching ester at wave number 1744.4 cm-1 and there is no stretching vibration of carboxylic acid -OH groups in the wave number area 3400- 2400 cm-1 and supported by the characteristic stretching absorption band of the -CO- C- group in the 1300-1000 cm-1 area where the absorption band with the smallest wave number on the right experiences a significant increase in absorption intensity. So that it can be concluded that there has been a process of substitution of the -CH3 group for the H atom of the -OH group of oleic acid.