Solid Vapor Equilibrium Research Articles

Vapour pressure of isotopic solids by a steady flow method: Argon between 72 °K and triple point

A steady state flow method was devised to measure the single stage separation factor in the solid-vapour equilibrium. The method was applied to the36A-40A solid system and found to work satisfactorily. The logarithm of the separation factor was found to depend linearly from 1/T2 within the experimental errors, ranging from 0.0104 at 72 °K to 0.0072 at triple point. This linear dependence is in agreement with the current theories of small quantum effects on thermodynamic systems. Using Bigeleisen’s formulation of the theory and taking into account anharmonic effects, the value of the mean square frequency of the lattice harmonic vibrations in solid argon is derived; this value agrees satisfactorily with specific heat measurements. The difference in triple point temperatures of40A and36A is derived from the measurements and found to be 0.0435 °K.

Natural Gas Hydrates at Pressures to 10,000 psia

Abstract This paper presents the results of the data obtained in the first stage of a long-range study at high pressures of the system, vapor-hydrate-water rich liquid-hydrocarbon rich liquid. The data presented are for the three-phase systems in which no hydrocarbon liquid exists. Tests were performed on 10 gases at pressures from 1,000 to 10,000 psia. One of these was substantially pure methane, and the remainder were binary mixtures of methane with ethane, propane, iso-butane and normal butane. Several conclusions may be drawn from the data.Contrary to previous extrapolations, the hydrocarbon mixtures tested form straight lines in the range of 6,000 to 10,000 psia which are parallel to the curves for pure methane, when the log of pressure is plotted vs hydrate formation temperature.The hydrate formation temperature may be predicted accurately at pressures from 6,000 to 10,000 psia by using a modified form of the Clapeyron equation. The total hydrate curve may be predicted by using the vapor-solid equilibrium constants of Carson and Katz to 4,000 psia and joining the two segments with a smooth continuous curve between 4,000 and 6,000 psia.The use of gas specific gravity as a parameter in hydrate correlations is unsatisfactory at elevated pressures.The hydrate crystal lattice is pressure sensitive at elevated pressures. Introduction Prior to 1950 many studies had been made of the hydrate forming conditions for typical natural gases to pressures of 4,000 psia. Most of these attempted to correlate the log of system pressure vs hydrate formation temperature, with gas specific gravity as a parameter. One of the more promising correlations was made by Katz, et al, which utilized vapor-solid equilibrium constants. The only published data above 4,000 psia are those of Kobayashi and Katz for pure methane to a pressure of 11,240 psia. In the intervening years, most published charts for the high-pressure range have represented nothing more than extrapolations of the low-pressure data, with the methane line serving as a general guide. The reliability of these charts has become increasingly doubtful (and critical) in our present technology as we handle more high-pressure systems.

Vapor–Solid Equilibria in the Iron–Chlorine System

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTVapor–Solid Equilibria in the Iron–Chlorine SystemLaurence E. Wilson and N. W. GregoryCite this: J. Phys. Chem. 1958, 62, 4, 433–437Publication Date (Print):April 1, 1958Publication History Published online1 May 2002Published inissue 1 April 1958https://doi.org/10.1021/j150562a015RIGHTS & PERMISSIONSArticle Views90Altmetric-Citations31LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (558 KB) Get e-Alerts

Vapor–Solid Equilibria in the Titanium–Oxygen System

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTVapor–Solid Equilibria in the Titanium–Oxygen SystemWarren O. Groves, Michael Hoch, and Herrick L. JohnstonCite this: J. Phys. Chem. 1955, 59, 2, 127–131Publication Date (Print):February 1, 1955Publication History Published online1 May 2002Published inissue 1 February 1955https://doi.org/10.1021/j150524a008RIGHTS & PERMISSIONSArticle Views133Altmetric-Citations34LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (575 KB) Get e-Alerts

Electrical Properties and the Solid-Vapor Equilibrium of Lead Sulfide

Electrical Properties and the Solid-Vapor Equilibrium of Lead Sulfide

Gas Hydrates of Hydrogen Sulfide-Methane Mixtures

Abstract Experimental data are presented for hydrate formation conditions for mixtures of hydrogen sulfide and methane. Vapor-solid equilibrium constants for hydrogen sulfide are also presented. Equilibrium constants, defined here as the ratio of the mole fraction of hydrogen sulfide in the vapor phase (dry basis) to the mole fraction of hydrogen sulfide in the solid phase (dry basis), were calculated using the vapor-solid equilibrium constants for methane presented in an earlier paper. The conditions at which a natural gas will form gas hydrates with water may be computed from its composition, when hydrogen sulfide is present in addition to carbon dioxide and the paraffin hydrocarbons. Introduction Many gases are known to form solid hydrates in the presence of liquid water at temperatures above 32°F. This hydrate formation is of importance to the natural gas industry inasmuch as most of the constituents found in natural gases will form hydrates. The attention of the industry was called to hydrates by Hammerschmidt in 1934. A number of papers have been written giving the temperatures and pressures at which these hydrates will form and a bibliography on the subject has been compiled. Deaton and Frost report work for various pure gases and for some natural gases. Katz and co-workers have reported data for various gases at high pressure. They developed a method of predicting conditions for hydrate formation from equilibrium constants and from gas gravity. The effects of anti-freeze agents on the formation of hydrogen sulfide hydrate were reported by Bond and Nelson. The hydrogen sulfide-water system, including hydrate, has been the subject of recent investigation by Sage and co-workers. Mixtures of hydrates behave as solid solutions and an equilibrium exists between the vapor phase and the solid phase that appears to be comparable to the equilibrium between vapor and liquid phases. By means of the vapor-solid equilibrium constants which have been published for methane, ethane, propane, isobutane, and carbon dioxide it is possible to determine the temperature and pressure at which hydrates will form for a specific gas mixture when water is present.

Gas Hydrates of Carbon Dioxide-Methane Mixtures

Abstract Experimental data are presented for hydrate formation conditions for gasmixtures of carbon dioxide and methane. Equilibrium constants for carbondioxide, defined as the mole fraction of carbon dioxide in the gas phase (drybasis) divided by the mole fraction of carbon dioxide in the hydrate (drybasis), were calculated using the equilibrium constants for methane developedin an earlier paper. Introduction A series of papers have been written on gas hydrates, giving temperaturesand pressures at which hydrates would form. Vapor-solid equilibrium constantshave been developed for methane, ethane, propane and iso-butane by which it ispossible to compute for a specific gas mixture the temperature and pressure atwhich hydrates will form. Carbon dioxide is present in many natural gases in concentrations usuallyfrom 0.1 to 2.0 per cent. It also forms a gas hydrate with water and presumablyenters the solid solution when present with a natural gas which is forming ahydrate. The equilibrium constant giving the ratio of the concentration ofcarbon dioxide in the gas phase to the concentration in the solid phase isrequired for including the effect of the carbon dioxide when computing theconditions for hydrate formation. Direct determination of the concentration of carbon dioxide in solid hydraterequires a difficult separation to be made. Therefore, this research resortedto the measurement of the temperature and pressure at which specific mixturesof methane and carbon dioxide would form hydrates. From the equilibriumconstants previously mentioned for methane, it is possible to compute theequilibrium constant for carbon dioxide, without measurement of the compositionof the solid phase. Fig. 1 shows the conditions at which methane and carbon dioxide formhydrates. T.P. 2578

Natural Gas Hydrates

Natural gases under pressure form crystalline hydrates with water.Experimental data are reported on four-phase equilibrium for themethane-propane-water, methane-pentane-water, and methane-hexane-water systems.Temperatures and pressures for equilibrium between gas, water-rich liquid, hydrocarbon-rich liquid, and hydrate were measured, as well as the percentagesof methane and propane in the hydrate. The data indicate that natural gashydrate behaves as a solid solution and that pentanes and heavier hydrocarbonsdo not enter into the solid phase. Vapor-solid equilibrium constants arepresented that permit the approximation of the conditions for hydrateformation, from the composition of a gas. Introduction Natural gas hydrates have been the object of considerable research in recentyears, because of the trouble they have caused in the natural-gas andnatural-gasoline industries. Natural gas hydrates are white crystallinecompounds of water and gas, which, under pressure, exist at temperaturesconsiderably above the freezing point of water. Because of the relatively hightemperatures at which the hydrates exist, they become a nuisance inhigh-pressure gas operations where water is present, since their formationcauses partial or complete plugging of valves and pipes. From a practicalstandpoint, the trouble incident to hydrate formation has been solved bydehydration of the gas before it enters the plant or pipe line, or by otherremedial measures. Extensive work on gas hydrates in the latter part of the nineteenth century, by Villard and others, gave data on methane hydrate and on ethane hydrate.Schroeder summarized these theoretical studies, Hammerschmidt introduced theinformation on gas hydrates to the gas industry, and Deaton and Frost gathereda considerable number of data on the behavior of natural gas hydrates. Recentpapers have extended both the data and the theory of these hydrates. At present, data are available on temperatures and pressures of hydrateformation for pure methane, ethane, propane, n-butane, methane-ethane mixtures, methane-propane mixtures, methane-butane mixtures, and some 15 natural gases, all in the presence of excess water. However, up to the present time no methodhas been available for predicting the temperature at given pressures or thepressure at given temperatures at which natural gases will form hydrates ifsaturated with water. T.P. 1371

Airy's theory of the rainbow

Cryogenic carbon capture from natural gas at high pressures requires accurate process synthesis and determination of process parameters due to the presence of solid–vapor and vapor–liquid–solid equilibria. At high pressures, the higher liquid formation not only causes operational problems, but also induces hydrocarbon losses in cryogenic packed beds. The present study proposes a novel multiple cryogenic desublimation based pipeline network with its sections at different cryogenic pressures and temperature profiles to enhance the separation. The experimental study explores the simultaneous separation of water and carbon dioxide from ternary feed gas mixture (CH4–CO2–H2O) by using multiple counter current cryogenic desublimation beds.A novel simulation strategy using multiple equilibrium temperature (MET) concept is also introduced for simulation studies. Simulation studies were subsequently conducted for both atmospheric and high cryogenic bed pressures and compared with experimental measurements. The effect of ambient humidity on dehydration was also investigated experimentally and it was observed that the humidity has significant effects on dehydration due to back diffusion. The effect of some important parameters like bed length, feed gas pressures, bed temperatures, feed flow rates and feed gas pressures for separation were investigated. Experimental investigation was also conducted to quantify liquid formation and vapor–solid equilibrium at high pressures. The experimental results of desublimation based cryogenic pipeline network showed promising potential for industrial exploitation.