Laser‐Mediated Photo‐High‐p,T Intensification of Vitamin D3 Synthesis in Continuous Flow

TitleLaser‐Mediated Photo‐High‐p,T Intensification of Vitamin D3 Synthesis in Continuous Flow
Publication TypeJournal Article
Year of Publication2018
AuthorsM. Escriba‐Gelonch, A. Halpin, T. Noël, V. Hessel
JournalChemPhotoChem
Volume2
Issue10
Pagination922-930
Date Published10/2018
Abstract

A new reactor design for photosynthesis in microflow is presented based on spatial overlap of a laser beam through a capillary tube. A conical Archimedean spiral facilitates exposure of the entire volume of the reaction solution to the irradiation beam. In this fashion, photo‐high‐p,T intensification of the photolysis of 7‐dehydrocholesterol is achieved using either a pulsed ultraviolet (UV) laser excitation (in the order of femtoseconds) alone or in tandem with a conventional UV lamp. The goal is to control the kinetics of the side photoreactions under pulsed photolysis, as well as to reduce the reaction time and enhance the vitamin D3 yield. Three kinds of effects are targeted: a) Utilizing a very large and spatially homogeneous photon flux inside the flowing solution; b) the novel process window of combining photo‐ with thermal intensification to promote the final, irreversible thermal step to vitamin D3; and c) the use of sub‐ps laser pulses to supply excitation energy on a timescale shorter than the formation of side photoproducts. Finally, photo‐processing with the laser alone is compared to the tandem irradiation by the laser‐UV lamp.

DOI10.1002/cptc.201800102
Division

MaSF

Department

PFE

PID

aca5f6d1b0d1425c578ec96ec5f2d49e

Alternate TitleChemPhotoChem

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