Chemical Engineering Journal, Vol.230, 547-557, 2013
Selective engineering using Mg-Al calcined hydrotalcite and microwave irradiation in mono-transesterification of diethyl malonate with cyclohexanol
Selectivity engineering aspects of synergism between microwave irradiation and solid base catalysis is investigated for a highly selective mono-transesterification of diethyl malonate with cyclohexanol using Mg-Al calcined hydrotalcite as catalyst. Microwave irradiation showed threefold increase in cyclohexanol conversion vis-a-vis conventional heating and only the mono-transesterified product was obtained. The catalyst was characterised by XRD, CO2-TPD, surface area and pore size analysis. Hydrotalcite with Mg:Al composition as 3:1 gave the best results. Effect of various parameters was studied on conversion and selectivity. Under optimised reaction conditions, 69% conversion with 98% selectivity for cyclohexyl ethyl malonate was obtained for catalyst loading of at 100 degrees C in 2 h. The catalyst showed excellent reusability. Complete theoretical and experimental analysis has been done to develop a kinetic model for the reaction. (C) 2013 Elsevier B.V. All rights reserved.
Keywords:Hydrotalcite;Microwave irradiation;Diethyl malonate;Cyclohexanol;Cyclohexyl ethyl malonate;Kinetics