The use of microflow reactors enabled dramatic improvements in the apparent rates of photochemical reactions. However, scaling-up of photomicroreactors remains a challenge due to the difficulties of distributing light and flow to all units of photomicroreactors. In this work, the mass and photon transfer limitations of an easily scalable micro-structured reactor, an aerosol photoreactor, was studied. In this reactor concept, each droplet works as a microreactor. The nature of aerosol light interaction enables good light distribution to all the droplets. A singlet oxygen mediated photosulfoxidation reaction was utilized as a model reaction to assess the reactor performance. The light transfer limitations were proven to be overcome in the aerosol photoreactor. The reaction rate constant was calculated as 0.12 s− 1. A simple solution of the convection–diffusion equation for a droplet was presented to check for the mass transfer limitations in aerosol reactors. The Sauter mean diameters of the droplets at different pressures varied between 7 and 8 μm. The aerosol photoreactor was proven to overcome the mass transfer limitations at these droplet diameters. In addition, the highest volumetric mass transfer coefficient (kLa) was calculated as 1.2 s− 1, which was at the same order of magnitude compared to other intensified pho- toreactors such as Corning Advanced Flow ReactorsTM or a gas–liquid microreactor. A discussion on increasing the throughput of aerosol photoreactors further is presented. This work paves the way for efficient and scalable photoreactors for industrial use.
The use of microflow reactors enabled dramatic improvements in the apparent rates of photochemical reactions. However, scaling-up of photomicroreactors remains a challenge due to the difficulties of distributing light and flow to all units of photomicroreactors. In this work, the mass and photon transfer limitations of an easily scalable micro-structured reactor, an aerosol photoreactor, was studied. In this reactor concept, each droplet works as a microreactor. The nature of aerosol light interaction enables good light distribution to all the droplets. A singlet oxygen mediated photosulfoxidation reaction was utilized as a model reaction to assess the reactor performance. The light transfer limitations were proven to be overcome in the aerosol photoreactor. The reaction rate constant was calculated as 0.12 s−1. A simple solution of the convection–diffusion equation for a droplet was presented to check for the mass transfer limitations in aerosol reactors. The Sauter mean diameters of the droplets at different pressures varied between 7 and 8 µm. The aerosol photoreactor was proven to overcome the mass transfer limitations at these droplet diameters. In addition, the highest volumetric mass transfer coefficient (kLa) was calculated as 1.2 s−1, which was at the same order of magnitude compared to other intensified photoreactors such as Corning Advanced Flow ReactorsTM or a gas–liquid microreactor. A discussion on increasing the throughput of aerosol photoreactors further is presented. This work paves the way for efficient and scalable photoreactors for industrial use.
Overcoming mass and photon transfer limitations in a scalable reactor: Oxidation in an aerosol photoreactor
Daniele Urbani;Alessandro Massi;
2021
Abstract
The use of microflow reactors enabled dramatic improvements in the apparent rates of photochemical reactions. However, scaling-up of photomicroreactors remains a challenge due to the difficulties of distributing light and flow to all units of photomicroreactors. In this work, the mass and photon transfer limitations of an easily scalable micro-structured reactor, an aerosol photoreactor, was studied. In this reactor concept, each droplet works as a microreactor. The nature of aerosol light interaction enables good light distribution to all the droplets. A singlet oxygen mediated photosulfoxidation reaction was utilized as a model reaction to assess the reactor performance. The light transfer limitations were proven to be overcome in the aerosol photoreactor. The reaction rate constant was calculated as 0.12 s− 1. A simple solution of the convection–diffusion equation for a droplet was presented to check for the mass transfer limitations in aerosol reactors. The Sauter mean diameters of the droplets at different pressures varied between 7 and 8 μm. The aerosol photoreactor was proven to overcome the mass transfer limitations at these droplet diameters. In addition, the highest volumetric mass transfer coefficient (kLa) was calculated as 1.2 s− 1, which was at the same order of magnitude compared to other intensified pho- toreactors such as Corning Advanced Flow ReactorsTM or a gas–liquid microreactor. A discussion on increasing the throughput of aerosol photoreactors further is presented. This work paves the way for efficient and scalable photoreactors for industrial use.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
