Hydrogen treating

Fig. 3. Refinery process for gas turbine fuels. Processing may include hydrogen treating.

Metal foils used as catalysts in the experiments described above turned out to be ill-fitted to these investigations. The electrolytic transformation of alloy foils into alloy hydrides did not guarantee a sufficient purity of the samples. Copper rich alloys should be excluded from the experiments because they could not be hydrogen treated in the same manner as the other alloys, and consequently no active microcrystalline layer was developed on their surface. 

Alonso-Vante N, Chatzitheodorou G, Fiechter S, Mgoduka N, PouHos 1, Tributsch H (1988) Interfacial behavior of hydrogen-treated sulphur deficient pyrite (FeS2 x). Sol Energy Mater 18 9-21... 

The first H-related line reported in hydrogen-treated doped GaAs was observed in GaAs Si. It was located at 896.82 cm-1 at LHeT and moved at 641.52 cm-1 in the D-treated sample (Jalil et at., 1987). The two lines were labelled 1-H and 1-D respectively. Fig. 12 shows line 1-H with the... 

This result is illustrated with STM line scans, as shown in Fig. 19, where data characterizing the edge of the freshly prepared, fully sulfided structures are compared with a similar line scan for an atomic hydrogen pre-treated cluster. The average height of the edge protrusions shifted down relative to the basal plane by approximately 0.2 A in the hydrogen-treated cluster. This downshift occurs as a... 

The EPR-detectable CO derivative in C. vinosum hydrogenase was shown by Van der Zwaan et al. (64) to be photolysed at low temperatures, yielding a product having the same spectrum as the photolyzed hydrogen-treated enzyme (Fig. 5c). Unlike the hydrogen-reduced species however, the rate of photolysis was unaffected by deuterium isotope substitution. 

TABLE 10. Catalytic activity of hydrogen-treated (473 K, 16 h) Cu7oZr3o catalysts in the hydrogena- ... 

Hydrofining —form of hydrogen treating in which refinery distillate,... 

Gulfining a catalytic hydrogen treating process for cracked and straight-run distillates and fuel oils, to reduce sulfur content improve carbon residue, color, and general stability and effect a slight increase in gravity. 

Untreated Purge Recovered Hydrogen Treated Purge... 

H. SIEGEL Bruce, along similar lines, can you say anything about the hydrogen treat rate that goes into the liquefaction reactor as a percent of coal feed or any other basis ... 

On the basis of the X-ray diffraction data it can be concluded that under the investigated conditions, in the initial and hydrogen-treated UDD powders, transformations in non-diamond carbon occur. With a rise in the temperature, in X-ray diffraction patterns of samples, the intensity of the halo at 20 18° increases, whereas the level of the background decreases (Fig. 3). 

The Arrhenius parameters of both treated Pd/SiC>2 catalysts are reported in table 1. The fresh and regenerated Pd/SiOj catalysts treated in hydrogen yield similar activation energies of 9.89 and 9.62 Kcal/mol, whereas oxygen-hydrogen treated catalysts have activation energies of 7.30 and 7.92 Kcal/mol respectively. The turnover frequencies (TON), listed in table 1, also follow the same trends when compared to the single crystal values. 

In recent years, a more severe type of hydrogen treating has been added to refinery processing systems in which heavy distillates (gas oil) and residuum are hydrotreated to remove sulfur and to convert these heavier hydrocarbons to products of lower molecular weight. The addition of "external" hydrogen increases the H/C ratio of the products substantially above that of the feed stocks. The use of these hydrocracking and... 

Figure 6. Surface area of PcFe supported on the activated and hydrogen treated V3G ( ) compared to the corresponding data on V3G ( ) and activated V3G (a), "Reproduced with permission from Ref. 16, Copyright 1983, Academic Press ".

Today, clay adsorption or hydrogen treating (catalytic hydrogenation) are used to accomplish decolorization [35]. Passage of oil through a clay coating on a continuous filter is quite effective and is suitable for small refineries. 

Methylcinnarnic acid (MCA) is a commercially available substrate for which the product ee was only 14% under the original conditions [86], and remained low (23%) after some improvement many years later [94]. However, the application of hydrogen-treated Pd/C under optimized conditions for PCA brought about a notable improvement in the hydrogenation of MCA that resulted in a 46% ee (Scheme 10.13) [100]. The product ee-value was higher with a bulkier a-substituent, while with a P-p-methoxyphenyl group the product ee was 86%. As... 

Calcination of powders in the presence of different gases may induce solid phase transformation, which in turn affects the PZC/IEP. Hydrogen-treated and untreated zirconia were studied in [160], but no substantial shift in CIP was detected. Two titanias were heated in O2 or in H2 at 530 or 6OO C, but no substantial change in lEP or CIP was observed in one sample [161], Dehydration of titania (rutile) as a function of temperature was studied in [162]. The Og of silica was depressed by a factor of 10 by heating at 800°C for 3 hours, further heating (up to 36 hours) did not affect CTq. Rehydration of heated powders for 3-56 days brought about a gradual increase in Og [163], A few examples of different phase transformations induced in the same initial material by calcination at various temperatures are presented in Chapter 3. 

Oxidized diamond (Fig. lb) can be prepared by oxidation of hydrogen treated diamond (900 °C with hydrogen gas Fig. la) with molecular oxygen at 450°C, and it contains functional C-O-C, C-OH, and C=0 groups on the top surface of solid diamond. This can be regarded as pseudo carbon oxide solid phase. 

As it has already been proposed for the hydrogen treated solid [22], the hydroxyl groups can recombine together, forming also water ... 

For hydrogen-treated M0S2, possible hydrogen species are shown in Fig. 7.31 with their calculated vibration frequencies according to the atom superposition and electron delocalization molecular orbital method [134]. Typical spectra of hydrogen-treated RuS2 and M0S2 [130,131] are shown in Fig. 7.32. 

This type of model may be used to confine a system to a lower dimension, and a particularly well known example of such a model is two-dimensional confined hydrogen (treated later), which has been applied to the theory of quantum dots so that the atoms are essentially confined to a plane. 

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