Volatile catalytic combustion

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... 

The SRCO catalytic combustion unit treats volatile organic compound (VOC) laden process exhaust air. SRCO stands for self-recuperative catalytic oxidizer. The SRCO can be furnished as a complete operating vacuum extraction and catalytic oxidation system or as a stand-alone catalytic oxidizer to interface with an existing vacuum extraction and/or air stripper system. HD-SRCO stands for halogenated destruction self-recuperative catalytic oxidizer. This system is basically the same as the SRCO system, except that it remediates halogenated hydrocarbons using a different catalyst. 

Sasahara,T., H. Kato, A. Saito, M. Nishimura, and M. Egashira. 2007. Development of a ppb-level sensor based on catalytic combustion for total volatile organic compounds in indoor air. Sens. Actuat. B B126 536-543. 

The air pollutants of volatile organic compoimds emitted from many industrial processes and transportation activities could be abated by catalytic combustion processes. Scire et al. reported the catalytic combustion of 2-propanol, methanol, and toluene on ceria-gold catalysts. The catalysts were prepared with coprecipitation and deposition-precipitation methods. The gold significantly enhanced the catalytic activity of ceria for the oxidation of these volatile organic compounds. The supposed reason is that the gold NFs weakened the mobility/reactivity of surface lattice oxygen (Scire et al., 2003). 

This contribution describes some physical properties of reverse w/o microemulsions, physical-chemical properties of platinum catalysts prepared by classical impregnation from water solutions of HaPtCle and from reverse w/o microemulsions comprising chloroplatinic acid and their activity in combustion of volatile organic compounds (VOC). In our study we concentrated on TweenSO (polyoxlethylen(20)sorbitan monoleate), as the surfactant does not comprise any potentially harmful ions (like sodium in AOT or bromide in CTAB) that could affect the activity of platinum in catalytic combustion. 

The increasing amounts of chlorinated volatile organic compounds (VOC), such as 1,2-dichloroethane (DCE) and trichloroethylene (TCE), released in the environment, together with their suspected toxicity and carcinogenic properties, have prompted researchers world-wide to find clean effective methods of destruction [1]. The abatement of chlorinated volatile organic compounds by catalytic combustion has been widely utilised in several technical processes. The lower temperatures required for catalytic combustion result in a lower fuel demand and can therefore be more cost effective than a thermal oxidation process [2]. In addition, the catalytic process also exerts more control over the reaction products and is less likely to produce toxic by-products, like dioxins, which may be generated by thermal combustion [3]. 

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. 

Catalytic combustion applications can be classified as either primary or secondary pollution control, that is, emissions prevention or emissions clean-up. The most common example of catalytic combustion for emissions clean-up is the catalytic converter in the exhaust system of automobiles. Catalytic combustion is also increasingly used for the removal of volatile organic compounds (VOCs) from industrial exhaust streams. The use of catalytic combustion in exhaust gas clean-up is discussed in other sections of this Handbook this section deals only with primary control applications. 

The public awareness about the impact of human activity on the environment exerts a tremendous pressure on most industrial manufacturers and leads to the development of environmental-oriented catalysis. One of the main issues in this research field is the concern about the abatement of volatile organic compounds (VOC). Here, dilute VOC-containing effluent streams are by far the most prevalent, which makes their non-catalytic combustion an expensive operation since it requires a supplemental fuel supply [1]. The catalytic combustion, however, can be carried out at relatively low temperature with little or no... 

The circulation loop reactor (CLR) is a novel dynamic reactor concept, which has been developed at our institute during the last years for the catalytic combustion of volatile organic compounds in waste air. It is described in [1] in detail. The reactor design presented in Fig.2.1 consists of three parts a heating zone at the reactor inlet, which is only used for the start-up procedure, a... 

Usually, under heating the destruction of organic compounds to be evaporated occurs on the surface of active alumina sorbents. This phenomenon results in the formation of harmful volatile compounds and the coke that decreases adsorbent capacity. Therefore, it seems more preferable to oxidize organic compounds to carbon dioxide and water during adsorbent regeneration. The processes and purification systems that combine the adsorption and the catalytic combustion regeneration were developed. The transition aluminas doped with catalytic... 

Everaert, K. and Baeyens, J. (2004). Catalytic Combustion of Volatile Organic Compounds, J. Hazard. Mater., B109, pp. 113-139. 

Musiahk-Piotrowska, A. and Syczewska, K. (1989). Destruction of Volatile Organic Mixtures by Catalytic Combustion, Environ. Prot. Eng., 15, pp. 117-126. 

Centeno, M., Paulis, M., Montes, M., et al. (2005). Catalytic Combustion of Volatile Organic Compounds on Gold/Titanium Oxynitride Catalysts, App/.Cafa/. B Environ, 61, pp. 177-183. 

Centeno, M.A., Paulis, M., Montes, M., and Odriozola, J.A. Catalytic combustion of volatile organic compounds on Au/Ce02/Al203 and AU/AI2O3 catalysts. Appl. Catal. A Gen. 2002, 234, 65-78. 

Scire, S., Minico, S., CrisafuUi, C., and Galvagno, S. Catalytic combustion of volatile organic componnds over gronp IB metal catalysts on Fe203. Catal. Commun. 2001, 2, 229-232. 

Santamaria and coworkers (Aguado cf a/.,2005) preparedPt/ZSM-5 membrane reactors for the combustion of n-hexane present at a low concentration in the air. Experimental results showed that n-hexane combustion was achieved at 210°C. A comparison of the conversion of the hexane obtained using the membrane reactor and the fixed bed reactor evidenced the better performance of the membrane reactor with a light-off temperature lower (about 70°C) than that obtained in the fixed bed reactor as illustrated in Fig. 6.5. Another example of the successful application of a Pt/ZSM-5 membrane in the catalytic combustion of volatile organic compounds (VOCs) (Bottino et al, 2001) showed that a high removal efficiency of toluene can be obtained and that the zeolite membrane with a relatively thick layer (40 pm) is clearly affected by mass transfer limitations. 

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