Optimization of Methyl Ester Through Simultaneous Esterification –Transesterification Reactions Using Waste Cooking Oil as Raw Material

Abstract

The increasing need for fossil energy does not equal the availability of alternative energy sources as a substitute generating new problems. In addition to decreasing availability, fossil energy harms the environment by producing dangerous gases from combustion such as carbon dioxide, sulfur, and nitrogen. These factors increasingly encourage researchers to create renewable energy sources with the same performance but are environmentally friendly. Biodiesel or Methyl Ester commonly called Fatty Acid Methyl Ester (FAME) is a renewable alternative energy produced from various raw materials such as animal, vegetable, or other oils. In this study, the methyl ester made from waste cooking oil was processed through two stages of esterification and transesterification using the addition of methanol with different catalysts, H2SO4 and NaOH relying on the reaction step. The research aimed to determine the optimal results from variations in the concentration of the acid catalyst used. From FTIR characterization found that functional groups indicating the formation of methyl esters have been identified at wave numbers 1800-1700 cm-1 with functional groups of -C=O ester the presence of FAME. Meanwhile, to determine the optimum methyl ester caloric value using Bomb Calorimetry according to ASTM D6751 standard. The caloric value was obtained at 9,572.58 Cal/g with catalyst 0,5% H2SO4. The methyl ester content was identified using GC-MS, and the results obtained for ME1, ME2, and ME3 are 74.90%, 77.15%, and 71.98%, respectively. From this study, it can be found that the methyl ester can be produced with esterification-transesterification reactions simultaneously.