Rasio Molar dan Konsentrasi Katalis Methyl Ester Sulfonic Acid pada Proses Sintesis Gliseril Ester

Abstract

Glycerol is a by-product of biodiesel industry production which still can be further processed into more value-added products. The example is the utilization of glycerol by means of esterification between glycerol and oleic acid with methyl ester sulfonic acid (MESA) catalyst, producing glyceril ester. The purpose of this study was to obtain the conditions of esterification with variable factors were molar ratio between oleic acid and glycerol and the concentrations of added MESA catalyst. Before esterification, crude glycerol was purified by adding 5% (v/v) phosphoric acid 85%, producing glycerol with ±80% glycerol content. Furthermore, glycerol was then esterified with supply of nitrogen, at temperature of 180 °C, and the stirring speed of 400 rpm for 90 minutes. The best combination of molar ratio and concentration of catalyst MESA is on ratio molar 0,8:1 (glycerol : oleic acid) with 0,5% added of catalyst MESA. Esterification on that condition produced glyceryl ester with the yield of 79,55%, density 0,940 g/cm3, acid value 44 mg KOH/g sample, viscosity 90 cP (30 oC), kinematic viscosity 49,04 cSt (40 oC), flash point 206 oC, pour point -1,5 oC, and boiling point 105 oC.