Optimization of a Scalable Photochemical Reactor for Reactions with Singlet Oxygen

摘要

Oxygenation of alpha-pinene using photochemically generated singlet oxygen (O-1(2)) was studied in detail in several continuous flow photochemical reactors. Ferrioxalate actinometry and reaction kinetic data were used to compare light sources and reactor geometries, such as the immersed-well, an annular recirculating and microfluidic reactors. It is shown that reactor miniaturization, control of intensity and of spectral composition of light, and elevated oxygen pressure are the crucial factors for safe and efficient photo-oxygenation reactions. Higher quantum yields were generally obtained with the microreactor-LED assemblies due to better energy utilization, compared to all other systems studied. For the single-phase microreactor-LED system, an optimization model has been developed that revealed a broad optimal design window.