Wet oxidation

About: Wet oxidation is a research topic. Over the lifetime, 3094 publications have been published within this topic receiving 61536 citations.

Catalytic wet air oxidation of butyric acid solutions using carbon supported iridium catalysts

Abstract: Aqueous solutions of butyric acid were treated by catalytic wet air oxidation using carbon-supported iridium catalysts in a stirred reactor. Under the operating conditions of 6.9 bar of oxygen partial pressure and 200 ◦ C of temperature, conversions up to 52.9% after 2 h were obtained depending on the type of catalyst used. The effects of butyric acid initial concentration, loading of catalyst, oxygen partial pressure and temperature were investigated and the empirical rate law for acid conversion is presented. Oxidation intermediates such as propionic and acetic acid were identified. The heterogeneous catalyzed free-radical oxidation of butyric acid is discussed. © 2002 Elsevier Science B.V. All rights reserved.

Activation of a Carbon Support Through a Two‐Step Wet Oxidation and Highly Active Ruthenium–Activated Carbon Catalysts for the Hydrogenation of Benzene

Abstract: A two-step liquid oxidation approach was developed for the activation of carbon materials. Following nitric acid treatment and subsequent liquid oxidation by a mild oxidant such as H2O2, the number of surface acidic functional groups was increased without destroying the physical structures of the carbon materials. Ruthenium catalysts supported on activated carbon prepared by this two-step liquid oxidation method show significantly improved Ru dispersion and excellent catalytic performance in the hydrogenation of benzene. The dispersion of ruthenium and the catalytic performance of Ru/activated carbon increases monotonically with the amount of surface functional groups.

Oxidative Phenol Degradation Using Non-Noble Metal Based Catalysts

Abstract: Phenol laden waste streams are not considered suitable for conventional biological treatment if phenol is present in amounts higher than 70 mg/L. Catalytic wet air oxidation (CWAO) is one of the potential methods for treating waste streams containing such compounds. The present work investigated the degradation of synthetic wastewater contaminated with phenol (1 g/L) using a CWAO process in the presence of homogenous (CuSO 4 ) and heterogeneous (LaCoO 3 , CuX and CuO-ZnO/CeO 2 ) catalysts. The reaction was conducted at low temperature (90°C) and atmospheric pressure, and at moderate operating conditions (T ≥ 160°C and total pressure ≤0.8 MPa). Among all the tested catalysts, CuSO 4 , LaCoO 3 and CuX were used for WAO reactions performed at atmospheric pressure conditions, whereas the performance of CuO-ZnO/CeO 2 catalyst was tested in above atmospheric pressure studies. At atmospheric conditions, homogeneous CuSO 4 was found to be the best showing ca. 90% phenol degradation and ca. 83% chemical oxygen demand (COD) reduction after a 24 h reaction period. The above atmospheric studies with catalyst showed ca. 82% phenol reduction and 54% COD removal within 3 h reaction time. The effect of pH, catalyst concentration, pressure and temperature are also reported. Finally, the major results are summarized and the recommendations for future work are given.

Electrolytic cell stack with porous surface active electrode for removal of organic contaminants from water and method to purify contaminated water

Abstract: A wet oxidation/reduction electrolytic cell stack, system, and method for the remediation of contaminated water is disclosed. A porous electrode of large surface area produces powerful oxidizing agents in situ without having to add any reagents, oxidizers, or catalysts to the water to be treated. Further, by the appropriate selection of electrode material, organic contaminants may be absorbed onto the surface of the electrode and subsequently oxidized to provide a dynamically renewable porous electrode surface. Flow rates, and power requirements may be tailored to the specific moieties to be removed, thus allowing local treatment of specific waste streams resulting in direct discharge to a publicly owned treatment works (POTW) or surface water discharge. A novel feature of this invention is the ability to remove both organic and metal contaminants without the addition of treatment reagents or catalysts.