Heterogeneous Photocatalysis for Indoor Air Purification: Recent Advances in Technology from Material to Reactor Modeling
01 Jan 2020-pp 147-166
TL;DR: In this article, the current status of PCO material technologies, coating methods, performance test methods, and modeling for real-world indoor air-purification application is reviewed and some recommendations for the future research on improving material selection and reactor design to minimize by-product generation and to promote commercialization are also discussed.
Abstract: Heterogeneous photocatalytic oxidation (PCO) has attracted much attention in indoor air-purification applications. Recently, researches focus on developing novel photocatalyst based filters for integrating with the heating, ventilation, and air conditioning (HVAC) systems as well as portable air purifiers. A comprehensive knowledge on factors influencing the indoor volatile organic compounds (VOCs) degradation has been established both in bench-scale and pilot-scale experiments. This paper reviews the current status of PCO material technologies, coating methods, performance test methods, and modeling for real-world indoor air-purification application. Due attention to the basic principle of PCO and the effect of operating parameters is provided, followed by a discussion on the modes of PCO application for buildings. The review also concentrates on the practical limitations in scaling-up PCO air purifiers for large-scale applications. Some recommendations for the future research on improving material selection and reactor design to minimize by-product generation and to promote commercialization are also discussed.
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References
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TL;DR: In this paper, the ultraviolet C-induced regeneration method was used for the recovery of photocatalytic activity of UVC filters with approximately 100 ppb of acetone or methyl ethyl ketone.
Abstract: Ultra-violet photocatalytic oxidation has been regarded as one of the promising air purification technologies for improving indoor air quality. However, limited availability of experimental data in terms of photocatalyst deactivation and regeneration has hindered successful implementation of ultra-violet photocatalytic oxidation air cleaners in mechanical ventilation systems. The objective of this study is to obtain knowledge of the ultraviolet C-induced regeneration method, the simplest on-site approach, for the recovery of photocatalytic activity of photocatalytic oxidation filters after challenging ultra-violet photocatalytic oxidation systems with approximately 100 ppb of acetone or methyl ethyl ketone. Experimental observations of photocatalyst deactivation, and characterization of fresh and deactivated photocatalyst with the scanning electron microscope technique were presented. During the regeneration process, the production rates of formaldehyde, acetaldehyde, and acetone were hourly quantified un...
9 citations
TL;DR: In this paper, the formation of submicron TiO2 smoke (a gas-phase suspension) from titanium tetrachloride in a low-pressure hydrolysis reaction in a simple reactor configuration has been studied.
Abstract: The formation of submicron TiO2 smoke (a gas-phase suspension) from titanium tetrachloride in a low-pressure hydrolysis reaction in a simple reactor configuration has been studied. Particle size distribution, particle morphology and degree of crystallinity have been characterized as a function of reaction conditions. Highly crystalline anatase TiO2 particles with narrow size distribution and smaller particle size were formed at high reactor temperature, while larger, amorphous particles were found at lower reactor temperatures. These results are consistent with literature studies. At 817 °C, small (450 nm), spherical, unagglomerated particles could be produced. A gas-phase dispersion of these particles is intended for use as seeds in subsequent kinetic studies of titanium dioxide formation reactions involving a rapid compression methodology.
5 citations