Synthesis of monoglyceride through glycerol esterification with lauric acid over propyl sulfonic acid post-synthesis functionalized SBA-15 mesoporous catalyst

Abstract

Monoglyceride synthesis through glycerol esterification with lauric acid over a propyl sulfonic acid functionalized SBA-15 mesoporous catalyst (HSO 3SBA-15) was studied under reduced pressure to continuously remove water formed. Effects of various reaction parameters such as reaction temperature (413–433 K), catalyst loading (1–5%) and glycerol/lauric acid molar ratio (2:1 and 4:1) on lauric acid conversion and products selectivity were successfully elucidated and correlated with reaction scheme and kinetic model. The parent and functionalized SBA-15 were characterized using FT-IR, ammonia chemisorptions, surface analysis, TEM and SEM. Reusability behavior of the catalyst was also demonstrated. Glycerol esterification could be modeled as irreversible parallel reactions and the kinetic data were successfully fitted to a second order kinetic model. The apparent activation energy for monoglyceride formation using a catalyst loading of 5% and glycerol/lauric acid molar ratio of 4:1 was found to be 42 kJ/mol. The HSO 3SBA-15 catalyst could be reused up to four times without significant loss of catalytic activity.