Optimisation of the glycerol acetylation process using graphene oxide catalyst

Abstract

Glycerol diversification from biodiesel production can be improved by converting it into high-value acetin products, for example, glyceryl monoacetate (MAG), glyceryl diacetate (DAG) and glyceryl triacetate (TAG) via the glycerol acetylation process with graphene oxide as a catalyst synthesised from Multi-Walled Carbon Nanotubes (MWCNT). Hummer's method was used to prepare graphene oxide. The acidity of the catalyst was examined, as well as FTIR, BET, XRD and SEM-EDX. This research aims to improve the glycerol acetylation to produce high glycerol conversion and acetins selectivity depending on the reaction circumstances. Process optimisation employs Response Surface Methodology (RSM) in conjunction with the Box-Behnken Design (BBD) method with three repeats of the midpoint. Temperature, mole ratio and catalyst loading (%) were all evaluated factors. The RSM process was optimised using Design-Expert software version 13, which resulted in a glycerol conversion of 93.04%. Moreover, with the selectivity of MAG 47.65%, DAG 29.21%, and TAG 23.36% at a temperature of 110°C, the mole ratio of glycerol and acetic acid (1:9) and the catalyst loading are 5%.

Keywords

• Acetylation
• Catalytic activity
• Glycerol
• Graphene oxide
• MWCNTs