Volatile organic compounds oxidation catalysts

It is fair to state that by and large the most important application of structured reactors is in environmental catalysis. The major applications are in automotive emission reduction. For diesel exhaust gases a complication is that it is overall oxidizing and contains soot. The three-way catalyst does not work under the conditions of the diesel exhaust gas. The cleaning of exhaust gas from stationary sources is also done in structured catalytic reactors. Important areas are reduction of NOv from power plants and the oxidation of volatile organic compounds (VOCs). Structured reactors also suggest themselves in synthesis gas production, for instance, in catalytic partial oxidation (CPO) of methane. 

Catalyst deactivation in the oxidation of volatile organic compounds by some metal oxides... 

Case histories for the deactivation of commercial Hopcalite and chhromia/alumina catalysts in the oxidation of volatile organic compounds (V0C) are presented. Feeds of pure hydrocarbons, chloro-carbons, and mixtures of the two are considered. Both fixed- and fluid-bed configurations have been studied. Deactivation with mixed feeds is a severe test of V0C catalyst capabilities. There seems here no clear distinction between between the type of reactor, but significant differences between activity and selectivity do exist. A simple model for predicting fixed-bed operation is presented. 

Since natural sunlight can only penetrate a few microns depth, the use of thin films of titania applied to ceramic or metallic supports as maintenance free decontamination catalysts for the photocatalytic oxidation of volatile organic compounds is of interest for the abatement or control of these emissions. The sol-gel technology can be readily incorporated as a washcoating step of the catalyst supports that may be subsequently heat-treated to fix the titania to the support. The surface area, porosity and crystalline phases present in these gels is important in controlling their catalytic activity. Furthermore, the thermal stability and development of porosity with heat-treatment was important if the sol-gel route is to be used as a washcoating step to produce thin films. 

Maira AJ, Lau WN, Lee CY, Yue PL, Chan CK, and Yeung KL. Performance of a membrane-catalyst for photocatal3ftic oxidation of volatile organic compounds. Chem Eng Sci 2003 58 959-962. 

Harris RH, Boyd VJ, Hutchings GJ, Taylor SH (2002) Water as a promoter of the complete oxidation of volatile organic compounds over uranium oxide catalysts. Catal Lett 78 369... 

Catalytic total oxidation of volatile organic compounds (VOC) is widely used to reduce emissions of air pollutants. Besides supported noble metals supported transition metal oxides (V, W, Cr, Mn, Cu, Fe) and oxidic compounds (perovskites) have been reported as suitable catalysts [1,2]. However, chlorinated hydrocarbons (CHC) in industrial exhaust gases lead to poisoning and deactivation of the catalysts [3]. Otherwise, catalysts for the catalytic combustion of VOCs and methane in natural gas burning turbines to avoid NO emissions should be stable at higher reaction temperatures and resists to thermal shocks [3]. Therefore, the development of chemically and thermally stable, low cost materials is of potential interest for the application as total oxidation catalysts. 

Catalysts for the oxidation of volatile organic compounds (VOC) are generally supported platinum or palladium catalysts. Copper oxide, vanadium oxide and chromium oxide are suitable for the oxidation of halogenated compounds. 

A knitted silica-fiber was produced and employed as a catalyst support. Different Pt, Pd and Ni/knitted silica-fiber catalysts were prepared. The activity of the catalysts was investigated in oxidation of volatile organic compounds, gas-phase hydrogenation of o-xylene, liquid-phase hydrogenation of citral and liquid phase enantioselective hydrogenation of 1-phenyl- 1,2-propanedione. 

Scire, S. and Liotta, L.F. (2012) Supported gold catalysts for the total oxidation of volatile organic compounds. Appl Catal. B Environ., 125, 222-246. 

Stege, W.P., Cadiis, L.E., and Barbero, B.P. (2011) Lai Ca Mn03 perovskites as catalysts for total oxidation of volatile organic compounds. CataL Today,... 

Garcia, T., Solsona, B., Cazorlaamoros, D., Linaressolano, A., and Taylor, S. (2006) Total oxidation of volatile organic compounds by vanadium promoted palladium-titania catalysts comparison of aromatic and polyaromatic compounds. Appl Catal B Environ., 62 (1-2), 66-76. 

Beauchet, R., Magnoux, P. and Mijoin, J. (2007). Catalytic oxidation of volatile organic compounds (VOCs) mixture (isopropanol/o-xylene) on zeolite catalysts, Catal Today, 124, pp. 118-123. 

Kim, S., and Shim, W. (2009). Properties and performance of Pd based catalysts for catalytic oxidation of volatile organic compounds, Appl. Catal. B Environmental, 92, pp. 429-436. 

Mitsui, T.,Tsutsui, K.,Matsui,T.,cta/. (2008). Support Effect on Complete Oxidation of Volatile Organic Compounds over Ru Catalysts, Appl. Catal. B Environ, 81, pp. 56-63. 

Spivey J, Butt J. Literature-review Deactivation of Catalysts in the Oxidation of Volatile Organic Compounds. Catal Today 1992 11 465-500. 

Dege, P., Pinard, L., Magnoux, R, et al. (2000). Catalytic oxidation of volatile organic compounds II. Influence of the physicochemical characteristics of Pd/HFAU catalysts on the oxidation of o-xylene,Appl. Catal. B Environ., 27, pp. 17-26. 

Cordi, E.M., O Neill, P.J., and Falconer, J.L. Transient oxidation of volatile organic compounds on a CUO/AI2O3 catalyst. Appl Catal B Environ. 1997, 14, 23-36. 

This chapter reviews recent advances in the use of ceria as a catalyst component in environmentally important catalytic processes. In particular, the oxidation of CO, the oxidation of volatile organic compounds (VOCs), the combustion of methane, and the reaction of NO with CO will be considered. 

S0rensen, M., M.D. Hurley, T.J. WaUington, T.S. Dibble, and O.J. Nielsen (2002), Do aerosols act as catalysts in the OH radical initiated atmospheric oxidation of volatile organic compounds , Atmos. Environ., 36, 5947-5952. 

Scire S, Minico S, Crisafulli C, Satriano C, Pistone (2003) Catalytic combustion of volatile organic compounds on gold/cerium oxide catalysts. Appl Catal B Environ 40(1-8) 43 19... 

DeVOx A catalytic oxidation process for destroying volatile organic compounds in effluent gases. The catalyst contains a non-noble metal and can easily be regenerated. Typical operating temperatures for 95 percent VOC conversion are 175 to 225°C for oxygenates, and 350°C for toluene. Developed in 1995 by Shell, Stork Comprimo, and CRI Catalysts. First installed in 1996 at Shell Nederland Chemie s styrene butadiene rubber facility at Pemis. 

Paulis, M Gandia, LM Gil, A Sambeth, J Odriozola, JA Montes, M. Influence of the surface adsorption-desorption processes on the ignition curves of volatile organic compounds (VOCs) complete oxidation over supported catalysts, Appl. Catal, B Environmental, 2000, Volume 26, Issue 1, 37-46. 

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