The critical temperatures and pressures of binary systems: Hydrocarbons of all types and hydrogen

AIChE Journal ◽  
1960 ◽  
Vol 6 (4) ◽  
pp. 561-566 ◽  
Author(s):  
Robert B. Grieves ◽  
George Thodos
Keyword(s):  
Binary Systems ◽  
Critical Temperatures

Binary Systems Containing Hydrocarbons IV. Miscibility Gaps in 18 Nitromethane + 1-, 2-, 3-and 4-alkenes

1971 ◽  
Vol 26 (10) ◽  
pp. 1713-1716
Author(s):  
Paolo Ferloni ◽  
Angela Geangu-Moisin ◽  
Paolo Franzosini ◽  
Mario Rolla
Keyword(s):  
Binary Systems ◽  
Critical Temperatures ◽  
Empirical Basis ◽  
Miscibility Gaps

AbstractLiquid-liquid equilibria in binary systems of nitromethane with 1-(C8-C9)-, trans-2-(C5-C9)-, trans-3-(C6-C9)-, trans-4-(C8-C9)-, 3-methyl-1-(C5)-, 2-methyl-2-(C5-C7)- and cis-2-(C6)-alkenes were investigated. Some regularities obeyed by the critical temperatures and compositions, as well as the possibility of foreseeing (on empirical basis) the two liquids region boundaries are discussed.

Vapor pressures and vapor liquid equilibria in the systems: (1) acetone – chloroform, (2) acetone – carbon tetrachloride, (3) benzene – carbon tetrachloride

1970 ◽  
Vol 48 (20) ◽  
pp. 3173-3184 ◽  
Author(s):  
A. N. Campbell ◽  
G. M. Musbally
Keyword(s):  
Carbon Tetrachloride ◽  
Liquid Phase ◽  
Binary Systems ◽  
Interaction Constant ◽  
Liquid Composition ◽  
Binary Interaction ◽  
Vapor Pressures ◽  
Critical Temperatures ◽  
Vapor Liquid Equilibria ◽  
System 1

The saturation vapor pressures of ten mixtures of the binary systems (1) acetone – chloroform, (2) acetone – carbon tetrachloride, and (3) benzene – carbon tetrachloride have been determined, from 100 to 230° for system 1 and from 100° up to the highest temperature at which liquid and vapor coexist for systems 2 and 3. The system acetone – chloroform could not be studied at higher temperatures because of decomposition.The gas–liquid critical temperatures of the three binary systems have been determined by the disappearance of meniscus method. The orthobaric compositions of the vapour–liquid equilibria of the binary systems have been measured from 100 to 180° for system 1 and from 100° to the critical region for systems 2 and 3, using a glass bomb enclosed in a steel bomb.From the vapour–liquid composition curves and the vapor pressure curves at constant temperatures (100, 150, 160, 170, and 180°), the existence of an azeotrope in the system acetone–chloroform at these temperatures, and having a composition of 36.2 mole% acetone at 100°, was confirmed. The composition of the azeotrope shifts towards lower acetone content as the temperature is raised. Azeotropes were not found in the systems acetone – carbon tetrachloride and benzene – carbon tetrachloride, over the ranges of temperature and pressure of this research.The data of the binary systems were treated thermodynamically to yield the liquid phase activity coefficients and, as suggested by Chueh and Prausnitz, the Redlick–Kwong equation was used in a modified form to obtain the fugacity coefficients of components in the vapor phase. Several liquid phase parameters, such as the binary interaction constant, Henry's constant, and dilation constant have been calculated, using the van Laar equation as modified by Chueh and Prausnitz.

The Cricondentherm and Cricondenbar Pressures of Multicomponent Hydrocarbon Mixtures

1964 ◽  
Vol 4 (03) ◽  
pp. 240-246 ◽  
Author(s):  
Robert B. Grieves ◽  
George Thodos
Keyword(s):  
Boiling Point ◽  
Binary Data ◽  
Binary Systems ◽  
Calculation Procedure ◽  
Hydrocarbon Mixture ◽  
Multicomponent Mixtures ◽  
Critical Temperatures ◽  
Average Deviation ◽  
Hydrocarbon Mixtures ◽  
Industrial Processing

Abstract A method is presented for the accurate calculation of the cricondentherm and cricondenbar pressures of multicomponent hydrocarbon mixtures of known composition. The mixtures may contain six and quite possibly any number of components including paraffins, isoparaffins, olefins, acetylenes, naphthenes and aromatics. The approach is similar to that used for calculating critical pressures and cricondentherm and cricondenbar temperatures. The critical pressure, the normal boiling point and the approximate vapor pressure behavior of each component are all that are required. A stepwise calculation procedure is necessary for mixtures containing more than two components. From an analysis of 22 binary systems and 118 mixtures, the average deviation of calculated cricondentherm pressures from reported values is 2.4 per cent. For nine multicomponent mixtures the average deviation is 1 per cent. Considering 19 binary systems and 108 mixtures, the average deviation of calculated cricondenbar pressures from reported values is 1.7 per cent. For 15 multicomponent mixtures, the average deviation is 2.2 per cent. Introduction A knowledge of the phase behavior in the critical region of multicomponent hydrocarbon mixtures is of value both in industrial processing operations and for the optimum operations of gas condensate reservoirs. Accurate methods of calculating the critical temperatures and critical pressures and cricondentherm and cricondenbar temperatures of multicomponent hydrocarbon mixtures are available in the literature. If the cricondentherm and cricondenbar pressures could be calculated with equal accuracy, the entire phase diagram of a multicomponent hydrocarbon mixture could be well approximated. The work of Etter and Kay is limited to systems containing the normal paraffins and has not been tested on systems containing a heavier component than heptane. In addition, the development of their multicomponent equations is based upon a limited number of mixtures containing from three to six components. Silverman and Thodos have considered systems containing both paraffinic and non-paraffinic hydrocarbons, but their correlation is limited to binary systems and is highly inaccurate for methane systems. Eilerts has done extensive work on the cricondenbar pressure; he has produced an excellent correlation for binary systems. However, his procedure for multicomponent mixtures is chiefly useful for highly complex mixtures requiring a knowledge of the vapor-liquid equilibrium behavior of the mixtures; he has not considered the cricondentherm pressure. The objective of this study was the development of an accurate and rapid method for the calculation of the cricondentherm and cricondenbar pressures of multicomponent mixtures containing all types of hydrocarbons and having a wide volatility range. The approach that was adopted is similar to that used by Grieves and Thodos for cricondentherm and cricondenbar temperatures and for critical pressures. However, methane systems had to be considered separately and a modified stepwise calculation procedure was utilized for the cricondentherm pressure. The correlations were developed in a manner similar to those for critical pressures and cricondentherm and cricondenbar temperatures. Based upon binary data reported in the literature it was observed that the ratios of cricondentherm and cricondenbar pressure to the pseudocritical pressure (molar average), pt/ppc and pp/ppc respectively, in two-component systems depended upon the mole fraction of this low-boiling component and upon the diversity in properties of the two components. A dimensionless boiling-point parameter T'b/Tb was chosen to represent the diversity in properties of the components. For a binary system, T't, is the molar average of the normal boiling points of the two components involved. SPEJ P. 240ˆ

Some Results of the Spectroscopic Study of Four Close Binary Systems of Early Spectral Types

1965 ◽  
Vol 5 ◽  
pp. 120-130
Author(s):  
T. S. Galkina
Keyword(s):  
Spectroscopic Study ◽  
Spectral Type ◽  
Spectroscopic Investigation ◽  
Binary Systems ◽  
Quantitative Information ◽  
Close Binary ◽  
Physical Parameters ◽  
Absorption And Emission ◽  
Close Binary Systems ◽  
Quantitative Estimates

It is necessary to have quantitative estimates of the intensity of lines (both absorption and emission) to obtain the physical parameters of the atmosphere of components.Some years ago at the Crimean observatory we began the spectroscopic investigation of close binary systems of the early spectral type with components WR, Of, O, B to try and obtain more quantitative information from the study of the spectra of the components.

Quasi-Periodic Oscillations in Dwarf Novae

1979 ◽  
Vol 46 ◽  
pp. 77-88
Author(s):  
Edward L. Robinson
Keyword(s):  
Binary Systems ◽  
Outer Edge ◽  
Light Curves ◽  
Close Binary ◽  
Bright Spot ◽  
Dwarf Novae ◽  
Periodic Oscillations ◽  
High Frequencies ◽  
Short Period ◽  
Typical Time

Three distinct kinds of rapid variations have been detected in the light curves of dwarf novae: rapid flickering, short period coherent oscillations, and quasi-periodic oscillations. The rapid flickering is seen in the light curves of most, if not all, dwarf novae, and is especially apparent during minimum light between eruptions. The flickering has a typical time scale of a few minutes or less and a typical amplitude of about .1 mag. The flickering is completely random and unpredictable; the power spectrum of flickering shows only a slow decrease from low to high frequencies. The observations of U Gem by Warner and Nather (1971) showed conclusively that most of the flickering is produced by variations in the luminosity of the bright spot near the outer edge of the accretion disk around the white dwarf in these close binary systems.

Rapid Critical Point Drying of Tissues in a Parr Bomb

1972 ◽  
Vol 30 ◽  
pp. 400-401
Author(s):  
C.A. Baechler ◽  
W. C. Pitchford ◽  
J. M. Riddle ◽  
C.B. Boyd ◽  
H. Kanagawa ◽  
...  
Keyword(s):  
Critical Point ◽  
Critical Pressure ◽  
Soft Tissues ◽  
Biological Tissues ◽  
Critical Temperatures ◽  
Air Drying ◽  
The Past ◽  
Critical Point Drying ◽  
Great Stress ◽  
Infiltration Techniques

Preservation of the topographic ultrastructure of soft biological tissues for examination by scanning electron microscopy has been accomplished in the past by using lengthy epoxy infiltration techniques, or dehydration in ethanol or acetone followed by air drying. Since the former technique requires several days of preparation and the latter technique subjects the tissues to great stress during the phase change encountered during air-drying, an alternate rapid, economical, and reliable method of surface structure preservation was developed. Turnbill and Philpott had used a fluorocarbon for the critical point drying of soft tissues and indicated the advantages of working with fluids having both moderately low critical pressures as well as low critical temperatures. Freon-116 (duPont) which has a critical temperature of 19. 7 C and a critical pressure of 432 psi was used in this study.

Bence-albee after 25 years: A new superior α-factor correction procedure for the quantitative analysis of oxides and silicates

1992 ◽  
Vol 50 (2) ◽  
pp. 1744-1745
Author(s):  
John T. Armstrong
Keyword(s):  
Quantitative Analysis ◽  
Electron Microprobe ◽  
Binary Systems ◽  
Correction Procedure ◽  
Geological Samples ◽  
The Past ◽  
Large Matrix ◽  
Computational Speed ◽  
Microprobe Data ◽  
Geological Sciences

One of the most cited papers in the geological sciences has been that of Albee and Bence on the use of empirical " α -factors" to correct quantitative electron microprobe data. During the past 25 years this method has remained the most commonly used correction for geological samples, despite the facts that few investigators have actually determined empirical α-factors, but instead employ tables of calculated α-factors using one of the conventional "ZAF" correction programs; a number of investigators have shown that the assumption that an α-factor is constant in binary systems where there are large matrix corrections is incorrect (e.g, 2-3); and the procedure’s desirability in terms of program size and computational speed is much less important today because of developments in computing capabilities. The question thus exists whether it is time to honorably retire the Bence-Albee procedure and turn to more modern, robust correction methods. This paper proposes that, although it is perhaps time to retire the original Bence-Albee procedure, it should be replaced by a similar method based on compositiondependent polynomial α-factor expressions.

Fractionation of polymethylene chains: An electron crystallographic investigation

1986 ◽  
Vol 44 ◽  
pp. 794-795
Author(s):  
Douglas L. Dorset
Keyword(s):  
Cross Section ◽  
Binary Systems ◽  
Linear Chain ◽  
Pure Component ◽  
Organic Substrates ◽  
Crystallographic Investigation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molecular Sizes ◽  
The Stability

A variety of linear chain materials exist as polydisperse systems which are difficultly purified. The stability of continuous binary solid solutions assume that the Gibbs free energy of the solution is lower than that of either crystal component, a condition which includes such factors as relative molecular sizes and shapes and perhaps the symmetry of the pure component crystal structures.Although extensive studies of n-alkane miscibility have been carried out via powder X-ray diffraction of bulk samples we have begun to examine binary systems as single crystals, taking advantage of the well-known enhanced scattering cross section of matter for electrons and also the favorable projection of a paraffin crystal structure posited by epitaxial crystallization of such samples on organic substrates such as benzoic acid.

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