Photo-microfluidic chip reactors for propene complete oxidation with TiO2 photocalyst using UV-LED light

Abstract

In this study, we present a photo-microreactor illuminated with a low power LED light as a highly efficient system to achieve the total oxidation of propene using a TiO2 photocatalyst. This abatement system (photo-microreactor) consists in an immobilized benchmark photocatalyst (TiO2, P25) inside a commercial glass microchannel chip (UV transparent microfluidic chips, internal volume of 9.5 μL) using a packed-bed configuration without any previous treatment. The P25 inside the microreactor shows a nearly homogenous filling of the particles resulting in a low pressure drop throughout the system. In terms of propene abatement (Catalytic activity), the P25 inside the commercial microreactor reaches total propene conversion (100%) under flow conditions at low concentrations (100 ppmv) due to shorter diffusion distances, large surface-to-volume ratios, efficient heat transfer , and the improved light penetration inside the microchannel.Moreover, the prepared microreactor uses a low consumption power (LED), low residence time and presents a relatively low pressure drop making this device (P25 inside a commercial microreactor) very interesting for the abatement of volatile organic compounds at low concentration for example at indoor ambient due to its small size (45 x 15 mm).

High power illumination system for uniform, isotropic and real time controlled irradiance in photoactivated processes research

“…Descriptions of illuminating systems may lack of the necessary detailed information, referring solely to the lamp model or its basic technical characteristics, which is clearly insufficient to evaluate the irradiance at the illuminated surface, even approximately [10] . Simple calculations involving strong assumptions like irradiance uniformity, normal incidence or the validity of the inverse square law for extended sources, that do not generally hold, will have unacceptable uncertainties [9] , [11] , [12] , [10] . Detailed irradiance calculations based in radiative transfer theory are complex and specific to each particular illumination-reactor geometry.…”

The integrated microfluidic photocatalytic planar reactor under continuous operation

“…Photocatalytic reaction is a clean and environmentally friendly green chemistry and is essentially a REDOX reaction (Fujishima and Zhang, 2006). In the late 1970s, the semiconductor TiO 2 was first used as a photocatalyst for cyanide degradation (Frank and Bard, 1977); later, the dechlorination degradation of PCBS by TiO 2 under 365 nm light has also been verified (Fernández-Catalá et al, 2019). Since then, photocatalytic technology has developed rapidly for water treatment, and research and applications of the environmentally friendly photocatalytic technology are increasing day by day (Wang et al, 1997).…”

Study on High-Efficiency Photocatalytic Degradation of Oxytetracycline Based on a Spiral Microchannel Reactor

“…The microreactor has a high specific surface area and a small cross-sectional area so that the reactor has a higher illuminated catalyst surface area per unit reaction volume, stronger ability to be penetrated by light, and better uniformity of space illumination. − In addition, the small size of the microreactor reduces the molecular diffusion distance and enhances the contact between the catalyst, active material, and pollutants . Chen et al used a microreactor to achieve high-efficiency photocatalytic degradation of tetracycline, whose degradation efficiency was 4.5 times higher than the bulk reactor .…”

“…Espíndola et al successfully enhanced the photocatalytic degradation of OTC by TiO 2 in a NETmix mili-photoreactor, and the reactor showed a high photochemical space–time yield (STY) . Fernández-Catalá et al used the photomicroreactor to oxidize the low concentration of propylene in the air by photocatalysis and achieved complete mineralization of propylene at a low residence time (0.14 mg min/mL) . Katoch et al studied the photocatalytic degradation of methyl orange in a serpentine microreactor, the degradation rate of the dye reached 96% when the irradiation time was only 15 min, and the degradation rate of methyl orange was only 76% when the reaction time was 225 min in the beaker .…”

“…17 Fernańdez-Cataláet al used the photomicroreactor to oxidize the low concentration of propylene in the air by photocatalysis and achieved complete mineralization of propylene at a low residence time (0.14 mg min/mL). 18 Katoch et al studied the photocatalytic degradation of methyl orange in a serpentine microreactor, the degradation rate of the dye reached 96% when the irradiation time was only 15 min, and the degradation rate of methyl orange was only 76% when the reaction time was 225 min in the beaker. 19 Microreactors have outstanding advantages in the field of photocatalysis.…”