Hot Spot‐Dependent Zeolitization of NaY Precursor Gel with High Dissipation Factor in Microwave Heating

Abstract

The thermal effect of microwave heating was investigated in a NaY aged precursor gel with high dissipation factor. The influence of power, position, and geometry of the cylindrical vessel was evaluated on hot spots and zeolite formation in a microwave oven. Higher powers and hot spots at higher temperatures led to more thermal heterogeneity and faster zeolite formation near the wall. The highest temperature gradient was achieved in the vessel which was placed off‐center on a turntable with the farthest distance from the center, and the zeolite formation occurred faster when it was in the center. The highest temperature gradient does not guarantee faster zeolite formation and higher crystallinity, while the nonthermal effects were significant and led to zeolite formation in the center of the gel at low temperatures.