Exhaust gases treatment

A nice example of cooperation between metal particles and a support with redox properties concerns the three-way catalysts for automotive exhaust gases treatment composed of a noble metal (Pt, Pd, Rh) on a support with ceria additive. The cooperation was put in evidence in the CO/NO/O2 reactions [135-137] and... 

Since the early seventies, perovskite oxides have been tried as potential replacement of three-way catalysts for car exhaust gases treatment. In Chapter 184 the ceria-containing three-way catalysts will be thoroughly covered while in this chapter we will refer to all the other formulations used for the reduction of nitric oxide. 

Acid Gas Purification Techniques for CO2 (carbon dioxide ) Benfield Process, Air Pollution Control Technology in Japan, Exhaust Gas Treatment Equipment, Kobe Steel, LTD., Tokyo, Japan, 2002 (nett21. unep.or.jp/CTT DATA/AIR/AIR 7/html/Air-208.html). 

Hoebink, J. H. B. J., and Marin, G. B. Modeling of Monolithic Reactors for Automotive Exhaust Gas Treatment, in A. Cybulski and J. A. Moulijn, Structured Catalysts and Reactors . Marcel Dekker, NY (1998). 

Weber, W.H. (2000) Raman applications in catalysts for exhaust-gas treatment, in Raman Scattering in Materials Science (eds W.H. Weber and R. Merlin), Springer,... 

The manufacture of fatty alcohol sulfate or ether sulfate can be divided into five stages process air preparation, sulfur trioxide generation, sulfation, neutrahzation, and exhaust gas treatment. 

Exhaust Gas Treatment. The gas effluent must be treated to comply with environmental regulations. The exhaust gas from the reactor contains traces of organic matter and unreacted SO3 and SO2 gases. The first two impurities are removed by... 

Modeling of Monolithic Reactors for Automotive Exhaust Gas Treatment... 

As such a monolith is different from a fluidized bed, which also shows a limited pressure loss, but in combination with serious axial dispersion in the emulsion phase at least. A major distinction between monolith and fluidized-bed reactors, however, concerns heat transfer rates to the surroundings. The latter are applied when heat effects due to reaction are to be compensated, while monolithic reactors can be considered as adiabatic for most practical purposes. In automotive exhaust gas treatment, adiabatic behavior is even stimulated by insulation of the reactor wall to promote a fast light-off of the reactor after a cold engine start. 

Although the present considerations are valid for monolith reactors in general, independent of the actual chemical reactions, details will refer mostly to the application of monoliths in automobile exhaust gas treatment, which has received most attention in the past and still is dominant in the practical use of monoliths. Several reviews treat the extensive literature on monoliths, among which is a very recent one [2]. 

As mentioned in the introduction, the following discussion on modeling results takes as a lead that distinction should be made between steady-state models, unsteady-state models, and dynamic models. The results mentioned focus mainly on automotive exhaust gas treatment, which application has been widely studied, with major emphasis on the oxidation of carbon monoxide. 

Assuming isothermal operation, some results are shown for the case of exhaust gas treatment. Typical data for the parameters are shown in Table 1. 

For automotive exhaust gas treatment. Oh [42] presented a transient, one-dimensional single-channel model that predicts the temperature and species concentrations as a function of axial position and time in both solid and gas phase. Uniform flow distribution was... 

Ceramic monoliths can be manufactured either by extrusion [6-31 ] or by corrugation [32-44], the former being the technique mainly used. By extrusion, ceramic monoliths of various materials can be produced, though cordierite or mullite monoliths are most used, especially as catalyst carriers in exhaust gas treatment [6-31]. 

Eow-temperature CO oxidation has many applications such as indoor air quality control, automobile exhaust gas treatment, and CO removal from hydrogen for... 

M. Gambini and M. Vellini, CO2 Emission Abatement from Fossil Fuel Power Plants by Exhaust Gas Treatment. J. Eng. Gas. Turbines Power-Trans. ASME 125(1), 365-373, Jan. (2003). 

Soot emitted from Diesel engines is hazardous for human health since it is made of inhalable particles [1] and contains gases and liquids adsorbed on its smrface, some of which (Polycyclic Aromatic Hydrocarbons) are suspected to be cancerogenic [2]. Virtually, soot-free Diesel exhaust may be obtained combining reduction of soot formation in the combustion chamber with exhaust gas treatment [3]. This latter is generally performed by a ceramic wall-flow filter that collects the carbonaceous particles while the filter regeneration is achieved by post-combustion of collected soot [3, 4]. 

The term catalytic combustion generally means a complete oxidation of hydrocarbons to C02 and H20 over solid catalysts. Catalyst technology for air-pollution control such as exhaust gas treatment, abatement of the emission of VOCs, combustion of diesel soot particles, and high temperature combustion have boosted research in catalytic combustion. 

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