Effect of pressure on hydrogenation

Kalinichev AG, Gorbaty YE, Bondarenko GV, Okhulkov AV. The effect of pressure on hydrogen bonding in water. Steam, water, and hydrothermal systems. Physics and Chemistry Meeting the Needs of Industry Ottawa, Canada NRC-CNRC, 2000 538-545. 

The effect of pressure on hydrogen is represented graphically in fig. 1 (p. 18), the product pv being plotted3 against the pressure p. Neon and helium resemble hydrogen in being less compressible than Boyle s law demands.4... 

The model examined here has been used in the past to study the effects of pressure on hydrogen. Although not discussed in the present article, the pressure exerted by a hydrogen-like atom when enclosed in a spherical cavity can easily be determined, as it is given by... 

While the foregoing concepts have been utilized to rationalize the product distribution obtained on hydrogenation of a number of monocyclic olefins, it should be noted that the effect of pressure on the stereochemistry of hydrogenation of steroidal double bonds has not been critically evaluated. 

Fig. I. Effect of pressure on the melting temperature of argon, (a) Pure argon, (b) argon-helium, (c) argon-hydrogen.Qualitative difference between curves (b) and (c) is due to the effect of composition on the liquid-phase fugacity of argon (M6).

Figure 3.7A Effect of Pressure on Induction Figure 3.7B Effect of Hydrogen on...

Effect of pressure on rate of reaction. Temperature, 25-26 °C hydrogen flow, 27.6 x 10-5 mole/sec catalyst weight, 0.976 g stirrer speed, 1500 rpm. 

Figure 2.19 provides the thermodynamic equilibrium data for methane decomposition reaction. At temperatures above 800°C, molar fractions of hydrogen and carbon products approach their maximum equilibrium value. The effect of pressure on the molar fraction of H2 at different temperatures is shown in Figure 2.20. It is evident that the H2 production yield is favored by low pressure. The energy requirement per mole of hydrogen produced (37.8 kj/mol H2) is significantly less than that for the SMR reaction (68.7 kj/mol H2). Owing to a relatively low endothermicity of the process, <10% of the heat of methane combustion is needed to drive the process. In addition to hydrogen as a major product, the process produces a very important by-product clean carbon. Because no CO is formed in the reaction, there is no need for the WGS reaction and energy-intensive gas separation stages.

Drake Ml, Righter K (2002) Determimng the composition of the Earth, Nature 416 39 14 Driesner T (1997) The effect of pressure on deuterium-hydrogen fractionation in high-temperature water. Science 277 791-794... 

A unique aspect of the catalytic activity of CA is the fact that the hydroxo form of the enzyme catalyzes the hydration of CO2 through the direct binding of CO2 to the hydroxo ligand, whereas the aqua form of the enzyme catalyzes the dehydration of hydrogen carbonate through a ligand substitution process. This difference in mechanism is nicely demonstrated by the overall volume profile shown in Figure 23, which was constructed on the basis of the effect of pressure on the catalytic hydration and dehydration processes. Both these catalytic processes show characteristic pH dependencies that center around the pXa value of the coordinated water molecule. Many model Zn(II) and... 

Typical effects of pressure on dry gas, butane, C5+ liquid, and hydrogen production are shown in Figures 2 and 3 for the reforming of a... 

The effects of pressure on hydrocarbon types in the liquid products (400°F fraction) and the carbon/hydrogen ratio in the total oil are... 

H. Yoshida, S. Konishi and Y. Naruse, Effects of Impurities on Hydrogen Permeability through Palladium Alloy Membranes at Comparatively High Pressures and Temperatures , J. Less-Common Metals, 89 429-36 (1983). 

---