78 research outputs found

    Technologies for the removal of phenol from fluid streams: a short review of recent developments

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    The available technologies for the abatement of phenol from water and gaseous streams are briefly reviewed, and the recent advancements summarized. Separation technologies such as distillation, liquid\u2013liquid extraction with different solvents, adsorption over activated carbons and polymeric and inorganic adsorbents, membrane pervaporation and membrane\u2013solvent extraction, have been discussed. Destruction technologies such as non-catalytic, supercritical and catalytic wet air oxidation, ozonation, non-catalytic, catalytic and enzymatic peroxide wet oxidation, electrochemical and photocatalytic oxidation, supercriticalwet gasification, destruction with electron discharges aswell as biochemical treatments have been considered. As for the abatement of phenol from gases, condensation, absorption in liquids, adsorption on solids, membrane separation, thermal, catalytic, photocatalytic and biological oxidation have also been considered. The experimental conditions and the performances of the different techniques have been compared

    A study of some bivalent metal divanadates and their catalytic activity in the oxidation of propane

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    The divanadates M(2)V(2)O(7) of a virtually unreducible and unoxidizable cation, Mg(2+), of a reducible cation, Cu(2+), and of an oxidizable cation, Mn(2+), have been prepared and characterized by X-ray diffraction, surface area measurements, skeletal IR and UV-vis-NIR spectroscopies, and DTA-TG analyses. These materials have also been tested as catalysts for propane oxidative dehydrogenation at two different contact times. Mg divanadate is more active and more selective than Mn divanadate, while Cu divanadate is a little bit more selective than the Mg compound. The activity is likely mainly associated to the redox behavior of V cations which could be improved by reducible centers. Gas phase phenomena predominate at relatively low contact times and higher temperatures while true catalytic phenomena are observed at higher contact times and lower temperatures

    Catalytic wet oxidation of phenol over lanthanum strontium manganite

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    The catalytic performances of lanthanum strontium manganite in catalytic wet oxidation (CWO) of a phenol solution under milder conditions of temperature and pressure, in a batch reactor, have been investigated. Aim of the study is the evaluation of the effect of temperature, catalyst loading, phenol concentration and stirrer speed on phenol conversion. Experimental data obtained from the different test conditions are best-fitted to evaluate the effective reaction order and the apparent activation energy

    Oxidation of ethane over vanadia-alumina-based catalysts: co-feed and redox experiments

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    The conversion of ethane in mixture with oxygen and helium (or air) over a V2O5/Al2O3 12:88 (w/w). and a V2O5-K2O/Al2O3 12:6:82 (w/w) catalysts has been studied. Results of co-feed experiments (with ethane-oxygen-He and with ethane-air feeds) and redox experiments, performed feeding pure ethane over fully oxidized catalysts, have been compared. Data concerning propane conversion over the same catalysts have also been considered. Over the heavily K-doped sample a direct combustion way to CO2 parallel to the oxydehydrogenation way to ethylene is likely to exist. On the contrary, over undoped vanadia-alumina the main combustion way is successive and mainly gives CO. Similar yields have been obtained but at lower temperatures for co-feed than for redox experiments. However, in similar conditions the productivities can be definitely higher in redox than in co-feed experiments. Nevertheless the conversion of ethane in the empty reactor gives rise to definitely higher selectivities and yields, although at very high temperatures, than the catalyzed reactions. (C) 2002 Elsevier Science B.V. All rights reserved

    Catalytic wet oxidation of phenol over lanthanum strontium manganite

    No full text
    The catalytic performances of lanthanum strontium manganite in catalytic wet oxidation (CWO) of a phenol solution under milder conditions of temperature and pressure, in a batch reactor, have been investigated. Aim of the study is the evaluation of the effect of temperature, catalyst loading, phenol concentration and stirrer speed on phenol conversion. Experimental data obtained from the different test conditions are best-fitted to evaluate the effective reaction order and the apparent activation energy
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