Catalytic performance of acidic ionic liquid in esterification of benzyl alcohol with butyric acid

Abstract

Response surface methodology is successfully applied to optimize esterification of benzyl alcohol with butyric acid by an ionic liquid viz., [HSO₃-pmim]HSO₄. The effects of various reaction conditions, including reaction time, alcohol/acid molar ratio, the amount of water carrying agent and ionic liquid are investigated. A Box–Behnken experimental design has been employed to search for the optimal yield of benzyl butyrate. The analysis confirms that the relationship between the amount of water carrying agent and the amount of ionic liquid is the most significant parameters affecting the yield of benzyl butyrate. The coefficient of determination of this model is 0.9907. The optimum reaction conditions are established and verified experimental trial performed for validating the obtained results. Under the optimum conditions, the yield of benzyl butyrate reaches 99.4 %. The ionic liquid could be reused five times without noticeable drop in activity.