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Wet Air Oxidation (wet + air_oxidation)

Distribution by Scientific Domains
Chemistry100%

Kinds of Wet Air Oxidation

  • catalytic wet air oxidation
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    Selected Abstracts

    Catalytic wet air oxidation of phenol using active carbon: performance of discontinuous and continuous reactors

    JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 7 2001
    Frank Stüber
    Abstract Catalytic wet air oxidation (CWAO) of an aqueous phenol solution using active carbon (AC) as catalytic material was compared for a slurry and trickle bed reactor. Semi-batchwise experiments were carried out in a slurry reactor in the absence of external and internal mass transfer. Trickle-bed runs were conducted under the same conditions of temperature and pressure. Experimental results from the slurry reactor study showed that the phenol removal rate significantly increased with temperature and phenol concentration, whereas partial oxygen pressure had little effect. Thus, at conditions of 160,°C and 0.71,MPa of oxygen partial pressure, almost complete phenol elimination was achieved within 2,h for an initial phenol concentration of 2.5,g,dm,3. Under the same conditions of temperature and pressure, the slurry reactor performed at much higher initial rates with respect to phenol removal than the trickle bed reactor, both for a fresh active carbon and an aged active carbon, previously used for 50,h in the trickle bed reactor, but mineralisation was found to be much lower in the slurry reactor. Mass transfer limitations, ineffective catalyst wetting or preferential flow in the trickle bed alone cannot explain the drastic difference in the phenol removal rate. It is likely that the slurry system also greatly favours the formation of condensation polymers followed by their irreversible adsorption onto the AC surface, thereby progressively preventing the phenol molecules to be oxidised. Thus, the application of this type of reactor in CWAO has to be seriously questioned when aiming at complete mineralisation of phenol. Furthermore, any kinetic study of phenol oxidation conducted in a batch slurry reactor may not be useful for the design and scale-up of a continuous trickle bed reactor. © 2001 Society of Chemical Industry [source]

    Catalytic wet air oxidation of high-strength organic coking wastewater

    ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 5 2009
    Lihua Han
    Abstract Catalytic wet air oxidation (CWAO) treatment of the high-strength organic coking wastewater over CeCu and CeMn catalysts were studied. The main factors affecting the activities of the catalysts were investigated. Experimental results showed that in the absence of rare-earth metal catalysts, CWAO process was also effective for high-strength organic coking wastewater treatment. The catalyst, prepared with the active component CuCe (2:1) and carried by ,-Al2O3/TiO2 calcined at 600 °C, has a higher activity. Up to 95.2% of the initial CODCr was removed at the reaction temperature of 180 °C and oxygen partial pressure of 1.2 MPa. The effect of the catalyst is equivalent to homogeneous catalysis improved by 60% over non-catalytic treatment. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source]

    Liquid phase mineralization of gel-type anion exchange resin by a hybrid process of Fenton dissolution followed by sonication and wet air oxidation

    ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 1 2009
    T. L. Gunale
    Abstract A hybrid process of Fenton dissolution followed by sonication and wet air oxidation (WAO), has been demonstrated to mineralize strongly basic anion exchange resin (gel type). The solid anion exchange resin beads could be dissolved in water by Fenton process wherein the copper-catalyzed hydrogen peroxide (H2O2) reaction makes the resin hydrophilic by the disintegration of polymer matrix. Sonication of the dissolved resin thus obtained made the waste stream more amenable to WAO. Parameters for Fenton dissolution and sonication were studied to aid effective mineralization by WAO. The kinetic studies of WAO were performed using copper sulfate (CuSO4) as the homogeneous catalyst, in the temperature range of 483,523 K. It is thus possible to address the disposal of solid ion exchange resin by the hybrid process, described here. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd. [source]