Photocatalytic Degradation of Toluene in Air Using a Fluidized Bed Photoreactor

Abstract

The photocatalytic degradation of toluene in air was carried out on particles ofTiO2in a photocatalytic reactor that had been developed to study the treatment of organic pollutants in a gaseous phase. Hypothetically, the fluidized bed technology of this reactor could make it possible to increase the mass transfer coefficients in comparison with those of conventional photoreactors. The photocatalytic particles used were prepared by mixingTiO2(Degussa P25) and starch in a methanol solution. The XRD and SEM results of these aggregates confirm the titanium dioxide (Degussa P25) characteristics, such as the presence of anatase on the particle surface and spongy and wrinkled morphology. Toluene concentrations varied from 0.9 to 199ppmv, and all the experiments were carried out with a flow rate of 300 NL/h. Toluene conversions from 77%to 100%were obtained in the range studied. In this work, the regeneration processes of deactivatedTiO2photocatalysts have been investigated using FT-IR and GC/MS techniques. Benzoic acid, benzaldehyde, and benzyl alcohol were the three major intermediate products identified.

KINETIC MODELING AND EXPERIMENTAL VALIDATION OF A PHOTOCATALYTIC FLUIDIZED BED REACTOR FOR n-HEXANE DEGRADATION

“…The VOC catalytic photo-oxidation process on irradiated surfaces has been studied since the 1990s (Hashimoto et al, 2006). Over the last years, application studies and method optimization reached gaseous pollutant degradation from chemical industry, for example perchlorethylene (Imoberdorg et al, 2007), trichlorethylene (Link and Kim, 2004), benzene, toluene, ethyl-benzene and xylenes (BTEX) (Park et al, 2011;Prieto et al, 2007;Yao and Kuo, 2015;Zhong et al, 2007). The technical difficulties associated with the application of this process are: low conversion caused by insufficient gas-radiation-catalyst contact (Boyjoo et al 2017), total mineralization requirement in continuous flow (Sleiman et al, 2009) and reaction by-products formation that induce the catalyst deactivation (Rochetto and Tomaz, 2015).…”

“…Yue et al (1983) originally proposed using the fluidized bed configuration to enhance the photoinduced synthesis of ammonia, since solids-radiation contact is increased in comparison to surfaceimmobilized reactors. Since then, Dibble and Raupp (1992), Lim and Kim (2004), Prieto et al (2007), Park et al (2011), Dashliborun et al (2013), Yao and Kuo (2015), among other authors, studied the possibility of VOC photo-oxidation in fluidized bed reactors using TiO 2 -impregnated particles, which enhance pollutant removal efficiency in comparison to immobilized catalyst (Geng et al 2008a). In the fluidized bed configuration, optical path, particle size distribution and bed void fraction affect solids irradiation and, hence, the reactor efficiency (Park et al, 2011).…”

Sequential‐based process modelling of VOCs photodegradation in fluidized beds

“…[6][7][8][33][34][35][36][37][38] Less attention has been paid to mineralization, particularly in FBPRs. [6][7][8][33][34][35][36][37][38] Less attention has been paid to mineralization, particularly in FBPRs.…”

“…Adsorption, condensation, and catalytic combustion are conventional methods that have some drawbacks, such as low removal efficiency and high operating costs. [6][7][8][9] PCO of acetone in air flow using titanium dioxide has previously been studied and the effect of various parameters on its photocatalytic efficiency has been reported. [2] The PCO process is normally operated at ambient temperature and pressure leading lower energy consumption as compared with conventional processes such as incineration.…”

Photocatalytic activity enhancement of TiO2 with adding Zn particles

“…Varieties of techniques have been employed to degrade those organic contaminants and advanced heterogeneous photocatalysis involving titanium dioxide (TiO 2 ) photocatalyst appears to be one of the most promising technology [1][2][3][4][5][6].…”