Determination by reactive absorption of the rate constant of the ozone reaction with the hydroperoxide anion

Abstract

International audienceThe reaction rate constant between the hydroperoxide anion (HO2−) and molecular ozone was evaluated from the reactive absorption method in the range of temperature from 20 to 35 °C. This reaction is crucial in the initiation step of the ozone decomposition, especially using the peroxone process which combines ozone and hydrogen peroxide in solution. A stirred-cell operated semi-continuously was used for this purpose. A high initial concentration of tert-butanol (0.05 mol L−1) was applied to efficiently scavenge all radicals and to avoid any parasite reaction. Based on the dissolved H2O2 concentration decreasing and the outlet ozone concentration time-course, the stoichiometry of the initiation reaction was determined, with one mol of H2O2 consumed per mol of ozone transferred. The chemical conditions were thoroughly selected to reach a fast pseudo-first order absorption regime. The reaction rate constant increased from 1.91 × 106–2.40 × 106 L mol−1 s−1 at 20 °C to 5.68 × 106–7.31 × 106 L mol−1 s−1 at 35 °C

Intensification of the O3/H2O2 advanced oxidation process using a continuous tubular reactor filled with static mixers: Proof of concept

“…This slight increasing might be due to reactions with both residual radicals or with byproducts. The literature usually supports a consumption of one mol of H 2 O 2 for two mol of O 3 using the peroxone process (C HP /C Oz = 0.5) whereas the initiation reaction involved the consumption of one mol of HO 2 for one mol of O 3 [11,17,45,46]. Thus, C HP /C Oz was most of time in the range 0.5-1 (Fig 3.b) (Fig.…”

Kinetic Modeling of Ozone Decomposition and Peroxone Oxidation of Toluene in an Aqueous Phase Using ab Initio Calculations

“…Recent applications of the peroxone process include naphthenic acids and disinfection byproducts . Other areas of active research are process intensification , and optimization of the peroxone process. A new development is electro-peroxone, where the hydrogen peroxide is produced electrochemically in situ . , Electro-peroxone has rekindled interest in the peroxone process in recent years.…”

NMR spectroscopic method for studying homogenous liquid phase reaction kinetics in systems used in reactive gas absorption and application to monoethanolamine–water–carbon dioxide

“…Reactive absorption is a common gas treatment process in the chemical industry. Examples include the removal of: phosgene with aqueous solutions of sodium hydroxide [1], nitrogen oxides with water or aqueous solutions of hydrogen peroxide, sulphuric oxides with water or with aqueous solutions of limestone [2], and ozone with aqueous solutions of hydrogen peroxide [3].…”