Keywords: Thermodynamic analysis; equilibrium; glycerolysis; glycerol monostearate

Abstract

Thermodynamic analysis was performed on the reaction producing glycerol monostearate (GMS) from glycerol and stearic acid to examine the reaction's feasibility. Generation of GMS by glycerolysis of glycerol with stearic acid or fatty acids is thermodynamically advantageous in accordance with the equilibrium constant, K. Thermodynamic analysis was carried out to determine the parameters that affect the glycerolysis reaction using MATLAB 2014A and Microsoft Excel 2013. The obtained values of ΔHro; ΔSroand ΔGro were + 45.69 kJ/mol; +1.144 kJ/mol.K and –1.074 kJ/mol. Equilibrium constants at 433.15 K, 453.15 K, and 473.15 K for this synthesis were favourable, at 5.76 x 1024, 1.43 x 1027 and 2.23 x 1029, respectively. The higher the temperature, the greater the value of ln K, which suggests a limitless equilibrium. The largest yield of the substances involved in the reaction was obtained at 473 K with C3H8O3 (0.2286 mol), C18H36O2 (0.0620 mol), C21H42O4 (0.4379 mol) and H2O (0.27131 mol). Negative ΔGro values for this reaction suggest that formation of glycerol monostearate (C21H42O4) was plausible and feasible, and the formation of reaction products at equilibrium was highly favoured. This prediction provides an overview of the reaction to ensure an optimal yield of glycerol monostearate.