Microwave assisted synthesis of silicalite—power delivery and energy consumption

Abstract

Silicalite was synthesized by microwave heating and two conventional heating methods: an ethylene glycol bath or an electric oven. The effects of microwave and temperature ramp rate on induction time, crystallization rate, morphology of silicalite and energy consumption were investigated. In a microwave oven the reaction time was significantly reduced due to the rapid heating rate, however, the final yield decreased compared with the conventional methods. When the same temperature ramp rates were used in both microwave heating and conventional heating, the induction time and the crystallization rate were similar and the effect of microwave was found only to enhance the final yield of silicalite. Regardless of the irradiation of microwave the slower temperature ramp rate increased the final yield of silicalite. Energy efficiency was not always high in microwave heating. However, if the temperature ramp rate is carefully controlled, silicalite can be produced with less energy in a microwave reactor.