Hydrogenations, catalytic

Catalytic dewaxing Catalytic hydrogenation Catalytic properties Catalytic pyrolysis Catalytic reduction Catalytic reforming... 

The hydrogen can be used for organic hydrogenation, catalytic reductions, and ammonia synthesis. It can also be burned with chlorine to produce high quaHty HCl and used to provide a reducing atmosphere in some appHcations. In many cases, however, it is used as a fuel. 

Final purification of argon is readily accompHshed by several methods. Purification by passage over heated active metals or by selective adsorption (76) is practiced. More commonly argon is purified by the addition of a small excess of hydrogen, catalytic combustion to water, and finally redistiHation to remove both the excess hydrogen and any traces of nitrogen (see Fig. 5) (see Exhaust control, industrial). With careful control, argon purities exceed 99.999%. 

The potassium salt of ethyl o-nitrophenylpyruvate is prepared essentially according to the method of Wislicenus and Thoma.14 However, the isolation of ethyl o-nitrophenylpyruvate has been eliminated by liberating the ester from its potassium salt in the acetic acid used as solvent for the hydrogenation. Catalytic... 

Adiponitrile is readily hydrogenated catalytically to hexamethylenediamine, which is an important starting material for the prodnction of nylons and other plastics. The electrochemical production of adiponitrile was started in the United States in 1965 at present its volume is about 200 kilotons per year. The reaction occurs at lead or cadmium cathodes with current densities of np to 200 mA/cm in phosphate buffer solutions of pH 8.5 to 9. Salts of tetrabntylammonium [N(C4H9)4] are added to the solution this cation is specihcally adsorbed on the cathode and displaces water molecules from the first solution layer at the snrface. Therefore, the concentration of proton donors is drastically rednced in the reaction zone, and the reaction follows the scheme of (15.36) rather than that of (15.35), which wonld yield propi-onitrile. 

Carbonyl groups may be hydrogenated catalytically, as carbon-carbon unsaturated linkages were (p. 191). It is, however, normally more difficult to effect the catalytic reduction of C=0 than of C=C, C=C, C=N, or C N, so that selective reduction of the former—in the presence of any of the latter—cannot normally be achieved catalytically. This can, however, be done with various, usually complex, metal hydrides. 

It is possible to produce some liquid hydrocarbons from most coals during conversion (pyrolysis and hydrogenation/ catalytic and via solvent refining)/ but the yield and hydrogen consumption required to achieve this yield can vary widely from coal to coal. The weight of data in the literature indicate that the liquid hydrocarbons are derived from the so-called reactive maceralS/ i.e. the vitrinites and exinites present (7 8 1 9). Thusf for coals of the same rank the yield of liquids during conversion would be expected to vary with the vitrinite plus exinite contents. This leads to the general question of effect of rank on the response of a vitrinite and on the yield of liquid products and/ in the context of Australian bituminous coals, where semi-fusinite is usually abundant/ of the role of this maceral in conversion. 

Moreover, the Nb complex hydrogenates catalytically aryl- and benzyl-substituted phosphine under similar conditions (Scheme 6.16) [149]. Kinetic studies show that the hydrogenation of triphenylphosphine into the monocyclohexyl, dicyclohexyl, and tricyclohexylphosphine are successive reactions, and the rate of hydrogenation of the arylphosphine decreases as the number of cyclohexyl substituents increases [153]. 

Other examples of arene hydrogenation by Ziegler-type catalysts have been reported [35]. However, none of them is discussed at this point as they are generally poorly defined. Likewise, some hydrogenation catalytic systems in either oxo or water-gas-shift conditions are only reported in the list of references for sake of information [24, 36]. 

Cinnamic acid may also be hydrogenated catalytically (p. 377). If the sodium amalgam method is chosen, the catalytic method should be practised with phenol. 

Hydrotreating Hydrogenation Catalytic Remove impnrities, satnrate HCs Residuals, cracked HCs Cracker feed, distillate, lube... 

HT - Hydrogen Thermal NT - Nitrogen Thermal HCD - Hydrogen Catalytic Dry... 

Phthalimide was hydrogenated catalytically at 60-80° over palladium on barium sulfate in acetic acid containing an equimolar quantity of sulfuric or perchloric acid to phthalimidine [7729]. The same compound was produced in 76-80% yield by hydrogenation over nickel at 200° and 200-250 atm [43 and in 75% yield over copper chromite at 250° and 190 atm [7730]. Reduction with lithium aluminum hydride, on the other hand, reduced both carbonyls and gave isoindoline (yield 5%) [7730], also obtained by electroreduction on a lead cathode in sulfuric acid (yield 72%) [7730]. 

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