Study of glycerolysis of lactic acid

Abstract

Increasing production of a biodiesel industry, will also increase the by-product of the industry, glycerol. Further processes were investigated to get an added value of the byproduct. Glycerol esters of lactic acid and in particulars glycerol monolactate is one of the more value of derivative material from glycerol, which is known as safe, nontoxic and biodegradable emulsifier in food, cosmetics, and pharmaceutical industries. This research aims to study the effect of temperature and reactant ratio to the rate of catalyst free glycerolysis reaction of lactic acid. Experiments were conducted in a three-necked flask equipped with a thermometer, a stirrer and a reflux condenser. The reactions were conducted for 4 hours at 100°C - 140°C while the mole ratios of glycerol to lactate acid were varied 1:1 to 5:1. The conversion of lactic acid to ester increased by increasing the reaction temperature. The results also showed that more glycerol ratio to lactate acid, the higher conversion of the acid was obtained. As of the variables studied, maximum conversion was 86.28% at mole ratio of reactants was 5:1, 140°C within 4 hours. Irreversible homogeneous second order reaction model was suitable with the experimental data.