Abstracts Book - IMRC 2018

• SF2-O015
STUDY OF BENZENE DEGRADATION IN A PHOTOCATALYTIC
REACTOR FOR ITS IMPLEMENTATION IN OCCUPATIONAL
ENVIRONMENTS
Fátima Montserrat Castañeda de la Hoya 1 , Gerardo Torres Delgado 1 , Joaquín Márquez Marín 1 ,
Rebeca Castanedo Pérez 1 , Miguel Ángel Badillo Ávila 1 , Cyntia I. Zúñiga Romero 1 , Orlando
Zelaya Ángel 2
1 Centro de Investigación y de Estudios Avanzados del IPN - CINVESTAV, Unidad Querétaro,
Mexico. 2 Cinvestav Zacatenco, Unidad Zacatenco, Mexico.
Most workers in a variety of occupational settings have the potential to be
exposed to hazardous substances present in the form of organic vapors.
Benzene is an organic compound used in a wide range of industrial processes
even when it is well known that it is a carcinogenic agent. Nowadays,
heterogeneous photocatalysis represents one of the most important
technologies in organic compounds degradation. For its implementation in
occupational environments, it is required the use of a photocatalytic device,
whose efficiency is mainly characterized by the term known as Clean Air Delivery
Rate (CADR). CADR depends on parameters such as: kind of contaminant,
concentration, flow rate, relative humidity, temperature, etc.
In this work, we study the photocatalytic degradation of benzene in a
recirculation closed-loop reactor (RCLR) system, simulating occupational
environments real contamination under conditions such: i) initial concentration
of benzene in air, ii) mass flow and iii) intensity of excitation light. The benzene
degradation vs time was measured using a gas chromatograph coupled with a
mass spectrometer. The RCLR system was based in earlier works of Valérie
Héquet et al., and Walker and Wragg; and it was manufactured in our laboratory.
In the modelling of the RCLR, it is considered that the whole system is
constituted by the coupling in series of two ideal reactors. One of them is the
photocatalytic device (PD) and the other is a perfectly mixed camera. As
photocatalytic material, titanium dioxide (TiO 2 ) deposited in the form of thin
films was used. The films were settled in a cuadrangular arrangment inside the
PD. These films correspond to the best ones obtained in our laboratory by solgel
method, reaching values for the rate constant of about 2.1 h -1 . The
contaminant concentration values used were ≤ 100 ppmv. The results showed
that benzene degradation follows a first order decay model and the CADR value
depends on initial concentration and flow rate, mainly. In our case, due to the