Hydrogenation binary systems

Switendick was the first to apply modem electronic band theory to metal hydrides [5]. He compared the measured density of electronic states with theoretical results derived from energy band calculations in binary and pseudo-binary systems. Recently, the band structures of intermetallic hydrides including LaNi5Ht and FeTiH v have been summarized in a review article by Gupta and Schlapbach [6], All exhibit certain common features upon the absorption of hydrogen and formation of a distinct hydride phase. They are ... 

Data for the hydrogen sulfide-water and the methane-n-hexane binary systems were considered. The first is a type III system in the binary phase diagram classification scheme of van Konynenburg and Scott. Experimental data from Selleck et al. (1952) were used. Carroll and Mather (1989a b) presented a new interpretation of these data and also new three phase data. In this work, only those VLE data from Selleck et al. (1952) that are consistent with the new data were used. Data for the methane-n-hexane system are available from Poston and McKetta (1966) and Lin et al. (1977). This is a type V system. 

Of the many possible non-hydrocarbon - water binary systems which are related to substitute gas processes, the data on only the water binaries containing H2S, C02, N2, and NH3 were used in this study. The treatment of hydrogen, a quantum gas, is different from that of the other gases. A separate paper will deal with the correlation of the data on hydrogen mixtures. 

The complex hydride Mg CoH is very similar to Mg FeH. In the binary system of Mg-Co there is no solubility of Co in either solid or liquid Mg and no inter-metallic compound, Mg Co, exists in equilibrium with other phases. However, in contrast to the Mg-Fe system, the intermetallic compound MgCo exists in equili-brium in the Mg-Co binary system (e.g., [14, p. 251]). The theoretical hydrogen capacity of Mg CoH is only 4.5 wt% which is obviously lower than that of Mg FeHg due to the presence of the heavier Co element and one less H atom in the hydride formula. 

Abstract—The equilibrium diagrams of the binary systems of sulphuric add with nitromethane and with o-y m- and p-nitrotoluene have been investigated. It has been shown that addition compounds of the type 1 1 are formed in these systems, analogous to the compound sulphuric acid-nitrobenzene (Chebbuuez Helv, Chim, Acta 1923 6 281 and Masson J. Chem. Soc. 1931 3201)t The formation of these addition compounds is due to hydrogen bonding between the components, rather than to proton transfer. Their stability in the crystalline phase seems to be contradictory to the known basicities of mononitrocompounds (Gillespie and Solomons J. Chem. Soc, 1957 1796), because of the effect of temperature on the equilibria in the liquid phase. 

In order to discuss the meaning of these viscosity isotherms we are going to apply the ideas about the viscosity of binary systems developed by one of us elsewhere [3] and to make use of the known data about the ionizations of these nitrocompounds in sulphuric acid [-5, 6], The viscosity isotherm of the system with nitromethane, showing strong negative deviations from additivity, does not necessarily mean that nitromethane does not interact with sulphuric acid in the sense of hydrogen bond formation and basic ionization. Cryoscopic investigations have shown that nitromethane ionizes as a weak base in sulphuric... 

Figure 1. Carbon abundance as a function of mass for both components of a close binary system at the onset of mass transfer. The region from Mx=0 to Mr=Mgi=8.1 Mo corresponds to the originally less massive component (gainer), whereas the carbon distribution of the loser is plotted from 8.1 Mo (surface) to 17.1 M (center). The first occurrence of hydrogen depleted layers (Xat<0.7) and the end of the Roche Lobe Overflow are indicated.

Pyrrole forms weaker NH-0 hydrogen-bonded complexes with ethers.106,1 6,157,163 The dipole moment of the pyrrole-1,4-dioxane complex shows it to be predominantly a binary system in which the pyrrole molecule occupies an axial position to the dioxane ring163 (see Section III, A, 2). Particularly strongly hydrogen-bonded NH-0=C complexes are formed between pyrrole and ketones.147,149,156 IR studies of the effect of the complex formation upon both the NH- and the C=0 stretching frequencies have been made. 

H. 0. Jones and J. K. Mathews found that when nitrosyl chloride and hydrogen are passed over reduced platinum cooled by a freezing mixture, the ammonium chloride produced contains 5 per cent, of hydroxylamine chloride. W. J. van Heteren found liquid chlorine and liquid nitrosyl chloride are miscible in all proportions. N. Boubnoff and P. A. Guye examined the f.p. of the binary system N0C1-C12, and found that the liquidus curve exhibits no maximum, and there is no sharp minimum at the eutectic temp., —109°, Fig. 99. The bending of the curve near —107° indicates... 

By Gibbs Phase Rule illustrated in this chapter s introduction, a second intensive variable is needed (in addition to either temperature or pressure) to specify the three-phase binary system with an inhibitor (F = 3 — 3 + 2). Typically, the concentration of the inhibitor in the free water phase is specified as the second intensive variable. Substances that have considerable solubility in the aqueous phase, such as alcohols, glycols, and salts, normally act as inhibitors to hydrate formation. The colligative mechanism of formation inhibition is aided by increased competition for water molecules by the dissolved inhibitor molecule or ion through hydrogen bonding for alcohols or glycols, or via Coulombic forces (for salt ions). 

Ng H-J., Kalra H., Robinson D.B., Kubota H., "Equilibrium phase properties of the toluene-hydrogen sulfide and n-heptane-hydrogen sulfide binary systems", J. Chem. Eng. Data.. 1980, 25, 51-55. 

Two early studies of the phase equilibrium in the system hydrogen sulfide + carbon dioxide were Bierlein and Kay (1953) and Sobocinski and Kurata (1959). Bierlein and Kay (1953) measured vapor-liquid equilibrium (VLE) in the range of temperature from 0° to 100°C and pressures to 9 MPa, and they established the critical locus for the binary mixture. For this binary system, the critical locus is continuous between the two pure component critical points. Sobocinski and Kurata (1959) confirmed much of the work of Bierlein and Kay (1953) and extended it to temperatures as low as -95°C, the temperature at which solids are formed. Furthermore, liquid phase immiscibility was not observed in this system. Liquid H2S and C02 are completely miscible. 

Robinson and Bailey (1957) and Robinson et al. (1959) studied the VLE in the ternary mixtures of hydrogen sulfide + carbon dioxide + methane. These investigations also included a few points for the binary system H2S + C02. The points for the binary mixtures were at temperatures between 4° and 71 °C and at pressures from 4 to 8 MPa. 

Experimental investigations into binary systems containing hydrogen sulfide and light hydrocarbons are summarized in table 3A.1. 

Kay, W.B. and Brice, D.B. 1953. "Liquid-Vapor Equilibrium Relations in Binary Systems. Propane-Hydrogen Sulfide System", Ind. Eng. Chem., 45 221-226. 

Chapoy, A., A.H. Mohammadi, B. Tohidi, A. Valtz, and D. Richon. 2005. Experimental measurement and phase behavior modeling of hydrogen sulfide - Water binary system, lnd. Eng. Chem. Res. 44 7567-7574. 

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