Selective formation of triacetin by glycerol acetylation using acidic ion-exchange resins as catalyst and toluene as an entrainer

• Acetylation of glycerol in the presence of toluene as an entrainer was investigated.
• Acidic ion exchange resins showed high activity and selectivity for triacetin.
• Amberlyst-70 showed best performance with yield to triacetin of >95%.
• Formation of a new byproduct diglycerol tetraacetate (DGTA) was observed.

Esterification of glycerol with acetic acid in the presence of toluene as an entrainer was performed over acidic Amberlyst ion-exchange resins in a batch reactor. Toluene continuously removed the reaction water, thus the chemical equilibrium was effectively shifted; the selectivity for the most desired product triacetin was dramatically increased. The influence of reaction conditions such as reaction time, acetic acid: glycerol molar ratio and catalyst amount were investigated. More than 95% selectivity to triacetin at complete glycerol conversion was obtained. The ion-exchange resin catalysts were reusable in subsequent runs, but due to some deactivation the triacetin yields deteriorated.

Figure optionsDownload high-quality image (77 K)Download as PowerPoint slide