Microwave synthesis of zeolites: 1. Reactor engineering

Studies in the past decade suggest that microwave energy may have a unique ability to influence chemical processes. These include chemical and materials syntheses as well as separations. Specifically, recent studies have documented significantly reduced time for the fabrication of zeolites employing microwave energy. However, the mechanism and engineering for the enhanced rates of syntheses are unknown. The results from different laboratories are not consistent, and experimental details are sparse. We studied the synthesis of silicalite employing two geometries in an oven with 2.45-GHz microwaves. The distribution of microwave energies within the reactors from simulation differed, and the morphologies and yields of the resultant zeolite also differed. Larger uniform silicalite crystals were formed in the larger reactor in which the variation in microwave energy distribution was greater. Engineering the energy distribution within a microwave synthesis reactor is necessary to understand and control the process.