Development Of Capillary-based PMMA LSC-Photomicroreactors

Solar photochemistry has always been regarded as an important means to solve the energy crisis and achieve sustainable development.A novel solar reactor inspired by the leaf,LSC-PhotoMicroreactor(LSC-PM,where LSC denotes luminescent solar concentrator)which combines the merits of microchannel reactor and LSC,has attracted wide attention due to its great potential in efficient,safe and scalable solar production.However,in order to make LSC-PMs significantly win over the conventional way of chemical production and truly realize industrial application,it is still necessary and imperative to optimize the LSC-PM,improve its energy conversion efficiency and expand its application window.In this work,polymethyl methacrylate(PMMA)is used as a new waveguide material,which overcomes the problem of luminescence instability.A simple and cheap method is applied to manufacture the capillary-based PMMA LSC-PM via microfabrication technology.Aiming at improving the performance of the novel capillary-based PMMA LSC-PM,research on intensification of photon transfer and mass transfer is conducted.First,a plate-capillary-plate bonding method is used to construct the capillary-based LSC-PM,so as to eliminate photon transfer loss as much as possible inside the photomicroreactor.The capillary insereted in the LSC-PM microchannel,with high chemical resistance,can avoid direct contact between the reaction mixture and the waveguide PMMA,making LSC-PM applicable for photochemical reactions using various solvents and containing multi phases.Second,mass transfer is remarkably enhanced by packing microspheres into the capillary of the LSC-PM as indicated by residence time distribution measurement.When the packing(glass bead)size is 850 ?m with the capillary inner diameter 2 mm,near plug-flow performance is achieved and the reaction rate is accelerated by 2 times with the high reaction productivity maintained for the model photoreaction.Based on the above work,more combinations of "luminescent molecules+photocatalyst",besides the only one combination for current LSC-PMs,are screened,proving that LSC-PMs can provide access to most visible light catalytic reactions.The photocatalytic oxidation of ?-terpinene using rose bengal as the photocatalyst is performed in a novel GREEN LSC-PM.When the residence time in the LSC-PM is 20 s,the yield of the product reaches 21.8%(versus a yield of 15%with a reaction time of 20 min in a batch reactor).The results obtained in this work not only help LSC-PM advance in respects of energy efficiency and reactor efficiency,but also provide a potential new direction towards the simultaneous intensification of mass and photon transfer for photocatalysis via a single method.Moreover,this work proves that LSC-PMs can accommodate both homogeneous and multiphase reaction conditions,which means that LSC-PM can be applied as a platform for implementing most visible-light-induced photocatalytic reactions.