Catalytic devices

Physical devices (catalytic devices) for the nonchemical treatment of water and, more specifically, devices for scale prevention that employ magnetic fields have been part of the water treatment marketplace around the world since its earliest days. These devices include electronic, catalytic, electrostatic, and magnetic water treatments. There are also various other types of more recent alternative technologies (to chemical treatments) now available in the marketplace. These are being promoted for use in treating all types of MU water, FW, and BW. 

Catalytic devices These nonmagnetic devices use a perforated non-ferrous tube to encourage small calcite seed crystals to form and reduce the risk of bulk water scaling. They are promoted for use in hard waters under conditions where supersaturation can easily occur. 

Comments from the catalytic devices industry have at least proposed that FW or MW water quality, recirculating water, and surface temperatures are key factors in determining whether such devices will perform. 

Figure 5.4. Catalytic device for DeNOx reaction coupled with non-thermal plasma.

The cobalt(II)15 and zinc(II)16 complexes of phthalocyanine(Pc), octcyano-Pc, and tetrasulfon-ato-Pc incorporated in poly(4-vinylpyridine-co-styrene) or Nafion films coated on graphite have also been examined as catalytic devices for dihydrogen electrogeneration in phosphate buffer. These catalytic systems were strongly suggested to be dominated by the electron transfer within the polymer matrix. The best catalytic film is that constituted of the nonsubstituted Con-Pc complex in poly(4-vinylpyridine-co-styrene), giving a turnover number of 2 x 10s h-1 at an applied potential of —0.90 V vs. Ag Ag Cl. 

Electron transport in electrode coatings containing redox centers is a necessary ingredient of their functioning as a catalytic device. They indeed serve as an electron shuttle between the electrode and the catalyst present inside the film. As discussed in the next section, the same molecule may play the role of catalyst and of electron carrier, since as shown earlier, redox catalysis is possible in these multilayered coatings. They may also be different, as exemplified is Section 4.3.6. 

Apte MG, Traynor GW, Froehlich DA, et al. 1989. The impact of add-on catalytic devices on pollutant emissions from unvented kerosene heaters. JAPCA 39(9) 1228-1230. 

Pompliano, D. L., Peyman, A. and Knowles, J. R. (1990) Stabilization of a Reaction Intermediate as a Catalytic Device Definition ofthe Functional Role ofthe Flexible Loop in Triosphosphate Isomerase, Biochemistry 29, 3186-3194. 

D. Pompliano, A. Peyman, and J. Knowles, Biochemistry, 29,3186 (1990). Stabilization of a Reaction Intermediate as a Catalytic Device Definition of the Functional Role of the Flexible Loop in Triose Phosphate Isomerase. 

A membrane reactor can be viewed as a catalytic device containing a membrane. The membrane can be catalyticaUy active or inert. In the former case, the reaction can take place within the membrane structure (if all the membrane is catalytic) or on the membrane surface (if only the membrane surface is catalytic). If the membrane is inert, the reaction usually occurs on catalytic particles packed close to the membrane (see Fig. 9.1(a) and (b)). 

The catalytic devices, developed by UOP-Arvin, Grace-Norris and Cyanamid-Walker, consisted of combined catalytic converter-noise mufflers with air pumps to supply the required oxygen, and were projected to add an annual overall cost (averaged over five years) of 26- 40 (1964 dollars) (15). 

Poriel, C., Y. Ferrand, P. Le Maux, C. Paul, J. Rault-Berthelofi and G. Simonneaux (2003). Poly(ruthenium carbonyl spirobifluorenylporphyrin) A new polymer used as a catalytic device for carbene transfer. Chem. Commun. 2308-2309. 

Copper phthalocyanine (CuPc) thin films deposited at room temperature (30°C) on quartz and post-annealed gold-coated quartz substrates were examined using FESEM [4]. Such structures can be used for the development of photoconductive or catalytic devices. FESEM images showed daisely packed nanoparticles and nanoflower-like structures on the annealed gold-coated quartz substrates. The further characterization by fiactal dimension of the assanbly of nanostructures in the films, estimated from FESEM images, agreed with optical measurranents and indicated significant effect and potential control of the electronic and optical propalies of these films. 

Catalytic devices are widely used throughout industry as a convenient means of estimating the concentration of flammable gases in air. The range of hazards encountered and the number of instruments available from many different manufacturers are increasing annually. However, the vast majority of these instruments use the same principles of detection and hence have many features in common. The purpose of this chapter is to describe these features and the advantages and disadvantages which result from them. 

In the vast majority of catalytic devices, the concentration of the gas of interest is measured as the heat liberated in a controlled chemical reaction. Thus, for example, in the oxidation of one mole of methane... 

Deng YQ, Neved TG, Ewen RJ, Honeybonme CL, Jones MG (1993) Sulfur poisoning, recovery and related phenomena over supported padadium, rhodiinn and iridium catalysts for methane oxidation. Appl Catal A 101 51-62 Ehrhardt JJ, CoUn L, Jamois D (1997) Poisoning of platinum surfaces by hexamethyldisdoxane (HMDS) application to catalytic methane sensors. Sens Actuators B 40 117-124 Firth JG, Jones A, Jones TA (1973) The principles of the detection of flammable atmospheres by catalytic devices. Combust Flame 21 303-311... 

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