Compressibility, gas phase

Moreover, the density of the compressible gas phase can be calculated from the modified Gas law ... 

A supercritical fluid is a compressed gas phase that exists at a temperature above the critical temperature and at a pressure above the critical pressure (Figure 5.1). Changes in temperature or pressure above the critical values cannot cause phase changes. 

Another correlation based on experimental data at 298 K from Ref 102 shows that the potential theory is able to predict the effect of decrease of the amount adsorbed at increasing pressure (curve 2 for propane in Fig. 20). This effect was originally explained by factors such as those involved in retrograde condensation [102]. A more detailed explanation may be given on the basis of Eq. (50) for the surface excess [110]. Ethylene and propane form liquids at high pressures developed under the action of the adsorption forces. Thus, the density n(x) in Eq. (50) is attributed to the liquid or near-liquid state, and rig is the molar density of a less compressed gas phase. With rising pressure, the value of rig may increase faster than n(x), so that the difference n(x) — rig decreases. 

The pilot scale plant was used to perform spray experiments with an excess of CO2. There is a continuous flow of CO2. The liquid which shall be atomized is added cyclic with a piston pump. Therefore, it is assumed that the flow regime in and upstream the nozzle is a two phase flow consisting of a compressed gas phase and a gas-enriched liquid phase. This flow regime equals to the flow regime of a flash atomization with internal flashing. The optically transparent capillary with an inner diameter of 1 x 10 m is assembled to the pilot scale plant to analyze the flow regime and to verify these assumptions. 

What is the fraction of throughput energy lost to compress liquid hydrogen from 0.1 to 30 MPa for pipeline delivery How does this compare to the fraction of throughput energy lost to compress gas-phase hydrogen from 0.1 to 30 MPa for pipeline delivery ... 

The experiment could be repeated at a number of different temperatures and initial pressures to determine the shape of the two-phase envelope defined by the bubble point line and the dew point line. These two lines meet at the critical point, where it is no longer possible to distinguish between a compressed gas and a liquid. 

Instead of concentrating on the diffiisioii limit of reaction rates in liquid solution, it can be histnictive to consider die dependence of bimolecular rate coefficients of elementary chemical reactions on pressure over a wide solvent density range covering gas and liquid phase alike. Particularly amenable to such studies are atom recombination reactions whose rate coefficients can be easily hivestigated over a wide range of physical conditions from the dilute-gas phase to compressed liquid solution [3, 4]. 

The pressure used in producing gas wells often ranges from 690— 10,300 kPa (100—1500 psi). The temperature of the inlet gas is reduced by heat-exchange cooling with the gas after the expansion. As a result of the cooling, a liquid phase of natural gas liquids that contains some of the LPG components is formed. The liquid is passed to a set of simple distillation columns in which the most volatile components are removed overhead and the residue is natural gasoline. The gas phase from the condensate flash tank is compressed and recycled to the gas producing formation. 

Rankine Cycle Thermodynamics. Carnot cycles provide the highest theoretical efficiency possible, but these are entirely gas phase. A drawback to a Carnot cycle is the need for gas compression. Producing efficient, large-volume compressors has been such a problem that combustion turbines and jet engines were not practical until the late 1940s. 

Phase Equihbria Models Two approaches are available for modeling the fugacity of a solute,, in a supercritical fluid solution. The compressed gas approach is the most common where ... 

It follows that the efficiency of the Carnot engine is entirely determined by the temperatures of the two isothermal processes. The Otto cycle, being a real process, does not have ideal isothermal or adiabatic expansion and contraction of the gas phase due to the finite thermal losses of the combustion chamber and resistance to the movement of the piston, and because the product gases are not at tlrermodynamic equilibrium. Furthermore the heat of combustion is mainly evolved during a short time, after the gas has been compressed by the piston. This gives rise to an additional increase in temperature which is not accompanied by a large change in volume due to the constraint applied by tire piston. The efficiency, QE, expressed as a function of the compression ratio (r) can only be assumed therefore to be an approximation to the ideal gas Carnot cycle. 

Vapor A gas that is at a temperature below the critical temperature, so that it can be liquefied by compression, without lowering its temperature. It is the gas phase of a substance, particularly of those that are normally liquids or solids at ordinary temperatures. 

D. P. Poe and D. E. Marthe, Plate height theory for compressible mobile phase fluids and its application to gas, liquid and supercritical fluid cliromatography , 7. Chromatogr. 517 3-29(1990). 

The equilibrium between a compressed gas and a liquid is outside the scope of this review, since such a system has, in general, two mixed phases and not one mixed and one pure phase. This loss of simplicity makes the statistical interpretation of the behavior of such systems very difficult. However, it is probable that liquid mercury does not dissolve appreciable amounts of propane and butane so that these systems may be treated here as equilibria between a pure condensed phase and a gaseous mixture. Jepson, Richardson, and Rowlinson39 have measured the concentration of... 

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