Catalytic conversion of glycerol to oxygenated fuel additive in a continuous flow reactor: Process optimization

A continuous-flow process using ethanol solvent and heterogeneous catalyst amberlyst-36 was developed for conversion of glycerol to solketal, an oxygenated fuel additive, and the process was optimized in this study using response surface methodology. A model was proposed based on Box-Behnken design. At optimum conditions (temperature of 25 °C, acetone-to-glycerol molar ratio of 4 and weight hour space velocity of 2 h−1) the maximum yield was obtained at 94 ± 2%. The presence of impurities such as water and salt in glycerol significantly reduced the yield at the optimum conditions. The catalyst could be regenerated and reused for 24 h with an insignificant sign of deactivation. The use of methanol as solvent at the optimal conditions proved to be potential in making the system more economical. The economic analysis for the process revealed the potential of converting glycerol into solketal – an alternative to methyl tert-butyl ether as fuel additive.