"Scaling-up of a Photoreactor for Formic Acid Degradation Employing Hydrogen Peroxide and UV Radiation"

M. LABAS, C. ZALAZAR, R. BRANDI, C. MARTÍN Y A. CASSANO

Santa Fe

Otro; International Seminar on Advanced Oxidation Technologies (ISAOT); 2002

Grupo de Reactores y Reacciones (INTEC-UNL-CONICET)

A model for scaling-up a homogeneous photoreactor has been developed and experimentally verified in a pilot plant size apparatus. The procedure is exemplified with the oxidation of dilute aqueous solutions of formic acid employing UV radiation (254 nm) and hydrogen peroxide. Firstly, the kinetic model and the kinetic parameters of the formic acid degradation are obtained in a well-stirred, small, batch flat-plate photoreactor (volume = 70cm3). The method employed in the analysis of the experimental results renders reaction rate expressions for formic acid and hydrogen peroxide that are independent of the reactor configuration. These kinetic equations and the corresponding kinetic constants are then used in a mathematical, ully deterministic model of a continuous flow, two meters long, annular reactor (0.0065 m2 of cross section for flow) operating in laminar flow regime to predict exit concentrations of formic acid and hydrogen peroxide. Irradiation is provided in both cases with two different types of Germicidal lamps. No additional experiments have been made to adjust the reactor model parameters. Theoretical predictions from the obtained representation of the reactor performance are compared with experimental data gathered in the much larger size, cylindrical flow reactor. Results show good agreement for the explored range of variables; the correspond to expected operating conditions in water streams polluted with low concentrations of organic compounds.