Oxygen regeneration

NOj, levels in the FCC flue gas typically range from 50-500 ppm. Nitrogen content of the feed, excess oxygen, regenerator residence time, dense phase temperature, and CO promoter all influence the concentration of NO. ... 

When the surface of a sensor is saturated with adsorbed active particles, the sensor loses its sensitivity and needs regeneration. The singlet-oxygen regeneration of ZnO sensors is obtained by heating in a hydrogen ambient at 500 - 600 K. 

CC12FCC1F2. These compounds are non-toxic and non-flammable, and their thermodynamic properties are ideally suited for the compression/ expansion cycle in cooling and heat pump appliances. However, CFCs are chemically very inert, so when they are vented into the atmosphere, they do not react with atmospheric constituents. They diffuse unscathed first into the troposphere, then penetrate slowly into the stratosphere. There, the solar UV radiation photodissociates these compounds, liberating free chlorine atoms (the C-Cl bond is weaker than the C-F bond). The chlorine atoms react with atmospheric O3 to form chlorine oxide, which in turn reacts with atmospheric atomic oxygen regenerating chlorine atoms ... 

The enzyme vanillyl-alcohol oxidase (VAO, E.C. 1.1.3.38) was examined in detail with respect to mechanism, structural properties, and biotechnological applications by van Berkel and coworkers, giving an excellent example of how detailed biochemical studies provide a basis for preparative biocatalytic applications (for recent reviews see[1, 21). The homooctamer with a monomer mass of 65 kDa was isolated and purified from Penicillium simplicissimum. The catalytic mechanism of VAO-catalyzed oxidation of para-alkyl phenols was studied in detail[3-5 After initial hydride abstraction from the Ca atom, a binary complex of the intermediate para-quinone methide and reduced FAD reacts with molecular oxygen, regenerating the... 

Two types of reactivations are mentioned,20 a nonoxidative hydrogen-rich one at 15- to 100-day intervals,21 and oxygen regeneration at longer intervals (6 to 12 months) to bum off coke buildup on the catalyst. Yields are given in Table 10.5 for commercial operations. 

The tacit assumption made in the preceding discussion that ozone is photochemically stable in the troposphere is basically incorrect, and we must finally consider this aspect. It is true that the photodissociation of ozone as far as it leads to 0(3P) atoms causes no losses, because their subsequent attachment to molecular oxygen regenerates ozone. In Section 4.2 it was shown, however, that a part of the O( D) atoms produced in the... 

Figure 11. Site population as a function of surface coverage -Oxygen regeneration of reduced grid. (Reproduced with permission from Ref. 5. Copyright 1963, A. I. CH. E. Journal.)...

Figure 5. Potassium superoxide Oxygen Regeneration Plate (ORP).

Table 3. Changes of internal environmental parameters during oxygen regeneration plate performance test. ...

Diphthalimidocarbonate is a new reagent for the synthesis of active esters. A new photolabile support and a new technique for the hold-in-solution method provide improvements in the liquid-phase synthesis of peptides. The carboxy-group of an A -acylated amino-acid is protected by conversion into an oxazole ring photo-oxygenation regenerates the carboxy-group as a triamide, which is activated for peptide synthesis (Scheme 148). ... 

L. Elikan, J. P. Morris, C. K. Wu and C. G. Saunders. 180-day life test of solid electrolyte system for oxygen regeneration. ASME paper 71-Av-32 (1971)1-12. 

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