Scaling up multiphase photochemical reactions using translucent monoliths

Abstract

Micro-photoreactors provide a high surface-area-to-volume ratio, ensuring homogeneous illumination and enabling the use of a very high apparent reaction rate. However, they are not often used in industry since they cannot accommodate the required throughput due to their small size. This work presents a scalable photoreactor design, based on the translucent monolith, which can handle large throughputs, relative to microreactors, while maintaining the benefits of a microreactor. The design procedure for these monoliths and methodology to scale-up single phase (liquid) and multiphase (gas/liquid) photoreactions, using this reactor design, are reported herein. The photo-oxidation of 9,10-diphenylanthracene with singlet oxygen was used as a benchmark reaction to compare the monoliths with other state-of-the-art photoreactors. It was shown that translucent monoliths could be successfully used to scale-up liquid and gas/liquid photoreactions while keeping a high space-time yield and energy efficiency (photochemical space-time yield).