Continuous Photo-Oxidation in a Vortex Reactor: Efficient Operations Using Air Drawn from the Laboratory

Area of Science:

• Chemical Engineering
• Organic Chemistry
• Reaction Engineering

Background:

• Continuous flow reactors offer advantages in chemical synthesis.
• Efficient gas-liquid mixing is crucial for many reactions, including those involving oxygen.
• Photochemical reactions often require specialized setups for gas introduction and mixing.

Purpose of the Study:

• To develop and demonstrate a vortex reactor for continuous flow thermal and photochemical reactions.
• To investigate the reactor's efficiency in gas dissolution and mass transfer.
• To showcase its application in synthesizing valuable compounds like artemisinin.

Main Methods:

• Construction of a vortex reactor utilizing a rotating cylinder to generate Taylor vortices.
• Computational fluid dynamics (CFD) for flow pattern visualization.
• Application of the reactor to photochemical reactions involving singlet oxygen and continuous synthesis of artemisinin.

Main Results:

• The vortex reactor facilitates efficient gas dissolution and mass transfer.
• Optimal air uptake was observed at 4000 rpm.
• Successful application in photochemical reactions and a three-step synthesis of artemisinin from dihydroartemisinic acid.

Conclusions:

• The vortex reactor is a versatile tool for continuous flow synthesis, particularly for reactions involving gases.
• It offers an efficient alternative for oxygen-mediated reactions, simplifying experimental setups.
• The reactor's design enables high efficiency in complex syntheses like that of artemisinin.