Comparison of the photocatalytic efficiencies of continuous stirred tank reactor (CSTR) and batch systems using a dispersed micron sized photocatalyst

Abstract

A dispersed photocatalyst system was combined with CSTR in order to develop an efficient photocatalytic reactor for continuous operation.

Fabrication, functionalization and performance of doped photocatalysts for dye degradation and mineralization: a review

“…In an attempt to address the latter concern, these workers have developed combined dispersed photocatalyst-CSTR system for continuous operation using two dyes (rhodamine B and metanil yellow) and a C-doped TiO 2 micron-sized catalyst. Colombo and Ashokkumar (2017) reported some very encouraging features of their system in that it could give an increase in degradation reaching as high as 110% in comparison with the batch mode of operation, and also to more prolonged (> 42 h) of continuous operation with no blockage of the filter material and no catalyst deactivation. Additionally, the incorporation of short and periodic sonication was found to be effective in inhibiting catalyst accumulation on the filter surface and hence leading to stable flow regimes (Colombo and Ashokkumar 2017).…”

“…Colombo and Ashokkumar (2017) reported some very encouraging features of their system in that it could give an increase in degradation reaching as high as 110% in comparison with the batch mode of operation, and also to more prolonged (> 42 h) of continuous operation with no blockage of the filter material and no catalyst deactivation. Additionally, the incorporation of short and periodic sonication was found to be effective in inhibiting catalyst accumulation on the filter surface and hence leading to stable flow regimes (Colombo and Ashokkumar 2017). From reactor optimization studies involving differently combined Ag, Pd and/or TiO 2 nanoparticulate photocatalyst assessed for the degradation of methyl orange and Rose Bengal, Pickering et al (2017) have demonstrated the significance of configurational effects of the plasmonic phenomena occurring in photocatalytic reactors.…”

“…Summing up, Athanasiou et al (2016) concluded that the innovative design formulated was in line with the ultimate goal of scale-up for an eventual treatment of a relatively large flow of 50 m 3 daily of contaminated water. In another interesting work, Colombo and Ashokkumar (2017) indicated that the CSTR configuration for process operations tends to be limited to the use of fixed-bed reactors, and this leads to significant decrease in the efficiency of the process. In an attempt to address the latter concern, these workers have developed combined dispersed photocatalyst-CSTR system for continuous operation using two dyes (rhodamine B and metanil yellow) and a C-doped TiO 2 micron-sized catalyst.…”

Heterogeneous Photocatalysis for Selective Formation of High-Value-Added Molecules: Some Chemical and Engineering Aspects

“…An appealing alternative is the impregnation of the photocatalyst on a moist quartz wool, as reported by Bazzo and Urawaka, although the missing control of the ratio CO 2 /H 2 O led to hardly comparable results. These results agree with a recent report on the comparison between batch and continuous systems for the photodegradation of organic pollutants . The authors highlighted the higher flexibility of a continuous system in which the photocatalytic activity increased up to 110% in comparison to that of a batch system.…”

Double-Inverse-Opal-Structured Particle Assembly as a Novel Immobilized Photocatalytic Material

“…In batch processes, particulate photocatalysts that are colloidally stable offer a large surface area that can be exposed to reactants under irradiation. However, to recycle these photocatalysts, the dispersion system requires separation and recovery processes [1,21], increasing the cost of the photocatalytic process in industrial applications. Therefore, photocatalysts immobilized on inert supports [22,23] ("immobilized-type" photocatalysts) that do not require a separation process have been studied as an alternative.…”