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.
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Journal: Applied Catalysis A: General - Volume 490, 25 January 2015, Pages 10–16