Pembuatan Metil Ester Asam Lemak dari Minyak Sawit melalui Reaksi Transesterifikasi pada Variasi Berat Katalis K2O/SiO2

Abstract

The production of fatty acid methyl esters from palm oil has been conducted using transesterification reactions, utilizing a catalyst derived from solid waste sludge from the PDAM. The sludge that has been cleaned and dried is then kilned at a temperature of 800°C where it will be analyzed using X-Ray Fluorescence (XRF) and a SiO2 content of 50,7% is obtained. The catalyst was synthesized through impregnation with the addition of KOH. The solid waste sludge from PDAM was processed through impregnation with KOH, resulting in the formation of a K2O/SiO2 catalyst. Subsequently, the material was exposed to a temperature of 500°C in a furnace for 2 hours. The catalyst was then analyzed using X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD). The main components present in the K2O/SiO2 catalyst are K2O, SiO2, and Fe2O3, with K2O being the predominant component at 61.6%. The experimental parameters in this study were the catalyst weight (3%, 5%, 7%, 9%) (w/w), a molar ratio of oil to methanol of 1:15, and a reaction temperature of 60°C for a duration of 120 minutes. The conversion of fatty acid methyl esters was analyzed using gas chromatography, while changes in functional groups in the fatty acid methyl esters were evaluated using FT-IR spectroscopy. The most effective conditions to achieve maximum conversion of fatty acid methyl esters were determined to be a catalyst weight of 9%, a molar ratio of 1:15, a reaction temperature of 60°C, and a reaction period of 120 minutes, with a conversion rate of 99.14%. Under the same conditions, the highest yield was also observed at 85.39%. The presence of fatty acid methyl esters was verified by observing three stretching vibration peaks within the wavenumber range of 1300 to 1000 cm-1, which correspond to the -C-O-C- bond. The stretching vibration of -C-O-C- in palm oil is characterized by a prominent peak in the middle position (second one). However, in fatty acid methyl esters, this vibration is