Regenerator effectiveness

PEDRiELLi p and SKIBSTED L H (2002) Antioxidant syneigy and regeneration effect of quercetin, (-)epicatechin, and (+)-catechin on a-tocopherol in homogeneous solutions of peroxidating methyl linoleate, JAgric Food Chem, 50, 7138-44. 

The particle emissions are maximized due to a lower NO production in the exhaust gases and a lower temperature range (limiting the passive regeneration effect). Therefore, the DPF loading autonomy is globally reduced. 

Dehydrogenases also represent a class of interesting enzymes since enantiose-lective reduction of ketones can lead to the production of enantiomerically pure secondary alcohols for the fine chemicals industry. Compared to liquid systems, in which the cofactor is often eliminated by the circulating phase in continuous systems, solid/gas catalysis can be highly suitable since it has been demonstrated that the cofactor is stable and its regeneration effective by addition of a second substrate. Also, stereoselective oxidation of secondary alcohols by these systems can help in the resolution of racemic mixtures. 

Regenerators quite frequently are chosen for applications where the heat-transfer effectiveness, defined as G actual/2ideal, must approach values of 0.98 to 0.99. It is clear that a high regenerator effectiveness requires a high heat capacity per unit volume and a large surface area per unit volume. 

Cosmetic compositions having skin-calming and skin-regenerating effects and process for the preparation thereof... 

Slovak. Catalyst regeneration, effects of impurities Span. 

The slight decrease in regeneration effectiveness observed at the highest pressure studied may be the result of the combined effect of increased density with decreased diffiisivity. 

Table IV. TMP Regeneration Effectiveness as a Function of Pressure at 150 °C, Using 120 min Regeneration Time...

Another set of experiments tested the effect of temperature while maintaining a constant isobutane density of 0.41 g/cm To obtain a constant density of the SC isobutene, pressure was adjusted at each temperature between 150 °C (111 bar) and 210 °C (220 bar). The results showed an apparent maximum in the TMP regeneration effectiveness between 190-210 °C, at about 78-83% recovered activity. Any increase in temperature increases all reaction rates and hence slow diffusing species may condense more rapidly and produce higher molecular weight hydrocarbons that could not to be extracted from the zeolite pores due to their larger size. 

Supercritical isobutane can provide complete activity recovery from partially deactivated USY catalysts. It can also be applied multiple times to maintain high levels of catalyst activity when the alkylation reaction is performed utilizing commercially available refinery blends. Pressure, temperature, and regeneration time played important roles in the SC isobutane regeneration process because of their effect on solute solubility, diffiisivity, surface desorption, hydride transfer rates, and coke aging. As a consequence, regeneration effectiveness may be maximized by manipulating those variables. 

Razelos, as reported in Refs. 15 and 29, proposed the following approximate procedure to calculate the counterflow regenerator effectiveness e for unbalanced and unsymmetric regenerators for C r > 1,0.25 < (hA) < 4, and the complete range of C and NTUe. For the known values of NTU , C, and C), calculate appropriate values of NTUe and C r for an equivalent balanced regenerator (C = 1), designated with a subscript m, as follows ... 

Finally, calculate the desired regenerator effectiveness e from... 

Bahnke and Howard s results for C = 1 and C > 5 are the same as those shown in Fig. 17.31a provided that the abscissa NTU is replaced by NTU . The regenerator effectiveness due to longitudinal conduction decreases with increasing values of X and C, with the maximum effect at C -1. 

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