Efficient Scale-Up of a Solvent-Free Photooxidation Using a High-Power LED-Based Photomicroreactor

Abstract

Recent advancements in light-emitting diode (LED) technology and photomicroreactors have provided a prudent roadmap for scaling-up the photooxidation processes. In this work, we presented a highly efficient, chromoselective, and wavelength-selective high-power LED-based photomicroreactor (HLPMR) for multikilogram ascaridole production through solvent-free α-terpinene photooxidation. First, we segregated kinetically controlled and mass transfer limited zones by implementing various operating schemes. Numerical investigations indicated that a simultaneous drop in the molar diffusion coefficient and reaction rate led to the decrease of α-terpinene conversion in the mass transfer limited zone. Kinetic investigations showed that apparent rate constants were improved by increasing the LED input power. Based on the rise in apparent constants and the control over the selectivity, we varied perfluoroalkoxy alkane (PFA) microchannel design configurations and its volume to increase the irradiated area for efficiently scaling-up the ascaridole productivity, space-time yield, and photochemical space-time yield to 3.5 kg/day, 9303.5 g L −1 h −1 , and 34.7 mol kW −1 day −1 , respectively. Predictive modeling using various supervised machine learning classifiers was executed to select the best possible photoreactor for this benchmark photooxidation. Random forest classifier showed better prediction performance using the train test split, cross-validation, and folding approaches among the implemented classifiers. Overall, HLPMR ensured a green and sustainable production of ascaridole with a multikilogram per day capacity.

Scale-up of slurry Taylor flow microreactor for heterogeneous photocatalytic synthesis of azo-products

“…When increasing the power of the light source, a greater number of photons is available to excite the reactants and facilitate their participation in the reaction, thus leading to an enhanced photocatalytic reaction rate and improved reactor throughput. 20,21,28,33,34 In the field of homogeneous photocatalytic reactions, high-power lasers and high-intensity LEDs have demonstrated their potential for process scale-up. 33–35 Laser light sources offer a concentrated spot and require special tunable beam expanders, thus making them suitable for batch-type photocatalytic reactions.…”

“…20,21,28,33,34 In the field of homogeneous photocatalytic reactions, high-power lasers and high-intensity LEDs have demonstrated their potential for process scale-up. 33–35 Laser light sources offer a concentrated spot and require special tunable beam expanders, thus making them suitable for batch-type photocatalytic reactions. In contrast, LED light sources have advantages such as compact size, easily adjustable light-emitting area, and long lifespan.…”