CONSTRUCTION OF A NOVEL CONTINUOUS FLOW REACTOR FOR SOLID-STATE PHOTOCHEMISTRY

Solid-state photoreaction has recently been given increased attention due to its high selectivity, which offers potential for the design of chiral synthesis and the shortening of synthesis pathways. One of the limitations faced in scaling up these solid-state reactions has been attributed to the lack of a controllable reactor. Existing photoreactors have been observed to encounter issues with mobile particles, such as particle blockage and attenuation of light transport during scale-up.

In this thesis, a multiphase flow tubular photochemical reactor has been designed through the application of a swirl-induced pipe, by which a ring distribution of particles has been generated. Through this design, particle accumulation is reduced, and uniform exposure of particles to light is facilitated. The particle distribution along the pipe has been obtained using the Eulerian method, and the k-ω shear stress transport (SST) turbulence model has been employed. The radiation transfer equation has been solved using the discrete ordinate (DO) model. The absorption coefficient was calculated based on the UV-absorption spectrum, while the scattering coefficient was determined through Mie scattering theory.

It has been shown that particles which would otherwise settle can be redistributed by the tangential velocity induced by the swirl-induced pipe, exhibiting an anti-blocking effect. Furthermore, the local volumetric rate of energy absorbed (LVREA) has been increased by up to approximately twice that observed in a straight pipe, due to the increased retention time introduced by the swirl. Various inlet conditions have been compared based on their corresponding LVREA and specific radiation absorption (absorbed energy per unit weight of particles), with the specific absorption found to have increased by 5% compared to the straight pipe.

Additionally, the introduction of the swirl pipe has been shown to enhance the continuous flow of solid particles, thereby supporting the development of flow chemistry involving solid materials. To further investigate the factors influencing reactor performance, parameters have been defined to describe the particle distribution. It has been found that a fully expanded and compact layer of solid particles is capable of receiving more photons. Through this work, insight has been provided into the role of swirl pipe insertion in photoreactor design.

• Gao, J
• BEng, MR

• University of Nottingham

• Request a Brochure
• Request more Info
• Request a Quote