Light Sources for Photochemical Processes – Estimation of Technological Potentials

Abstract

This work theoretically evaluates light sources currently commercially available for the suitability to drive photoreactions. Comparative evaluation of different light sources reveals significant advantages of light‐emitting diodes (LEDs) in the near UV and visible region, underlining the general superiority of narrow‐band monochromatic light sources for photochemical processes. A generic analysis based on the average volumetric rate of photon absorption shows the limits resulting from physical fundamentals and the importance of the photon fluence rate for process intensification.

Thiol−Ene Coupling in a Continuous Photo‐Flow Regime

“…The lack of infrared component significantly facilitates process temperature control, the latter which may be challenging in systems using pressure lamps. All of these phenomena account for a more efficient energy use and may dramatically reduce operational cost ,. In combination with more general advantages associated to LED irradiation (i. e., not UV specific), such as long lamp lifetime, mercury‐free assembly, and ease of operation, a particularly economical, practical, and safe setup is obtained.…”

Beyond electrolysis: old challenges and new concepts of electricity-driven chemical reactors

“…A variety of light sources can be used in photochemistry, 45 with mercury lamps being still the most common solution in large-scale applications. The main features of the most relevant light sources used or studied in photochemical reactors are presented in Table 2.…”

Rapid Prototyping for Photochemical Reaction Engineering

“…The reactor design is mainly governed by the need to irradiate the reactants optimally meaning to reduce the number of unused photons. The optical path length is the most important parameter in this context . It directly influences the macroscopic reaction rates as well as heat and mass transport.…”