Densities of Toluene, Carbon Dioxide, Carbonyl Sulfide, and Hydrogen Sulfide over a Wide Temperature and Pressure Range in the Sub- and Supercritical State

2001 ◽  
Vol 40 (20) ◽  
pp. 4470-4477 ◽  
Author(s):  
E. Christian Ihmels ◽  
Jürgen Gmehling
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Sulfide ◽  
Pressure Range ◽  
Carbonyl Sulfide ◽  
Supercritical State ◽  
Temperature And Pressure

scholarly journals Thermodynamic modeling of solid solubility in supercritical carbon dioxide: Comparison between mixing rules

2013 ◽  
Vol 19 (3) ◽  
pp. 389-398 ◽  
Author(s):  
Hadi Baseri ◽  
Ali Haghighi-Asl ◽  
Nader Lotfollahi
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Thermodynamic Modeling ◽  
Pressure Range ◽  
The Other ◽  
Mixing Rules ◽  
Calculation Results ◽  
Temperature And Pressure ◽  
Robinson Equation ◽  
Supercritical Carbon

In this paper, Peng Robinson equation of state is used for thermodynamic modeling of the solubility of various solid components in the supercritical carbon dioxide. Moreover, the effects of three mixing rules of Van der Waals mixing rules, Panagiotopoulos and Reid mixing rules and modified Kwak and Mansoori mixing rules on the accuracy of calculation results were studied. Good correlations between calculated and experimental data were obtained in the wide temperature and pressure range. A comparison between used models shows that modified Kwak and Mansoori mixing rules give better correlations in comparison with the other mixing rules.

Free-Radical Chemistry in Supercritical Carbon Dioxide

2004 ◽  
Author(s):  
J. M. Tanko
Keyword(s):  
Carbon Dioxide ◽  
Free Radical ◽  
Supercritical Carbon Dioxide ◽  
Green Chemistry ◽  
Chemical Reactions ◽  
Environmentally Benign ◽  
Supercritical State ◽  
Liquid Phases ◽  
Temperature And Pressure ◽  
Supercritical Carbon

During the 1990s, the chemical industry has focused on ways to reduce and prevent pollution caused by chemical synthesis and manufacturing. The goal of this approach is to modify existing reaction conditions and/or to develop new chemistries that do not require the use of toxic reagents or solvents, or that do not produce toxic by-products. The terms “environmentally benign synthesis and processing” and “green chemistry” have been coined to describe this approach where the environmental impact of a process is as important an issue as reaction yield, efficiency, or cost. Most chemical reactions require the use of a solvent that may serve several functions in a reaction: for example, ensuring homogeneity of the reactants, facilitating heat transfer, extraction of a product (or by-product), or product purification via chromatography. However, because the solvent is only indirectly involved in a reaction (i.e., it is not consumed), its disposal becomes an important issue. Thus, one obvious approach to “green chemistry” is to identify alternative solvents that are nontoxic and/or environmentally benign. Supercritical carbon dioxide (sc CO2) has been identified as a solvent that may be a viable alternative to solvents such as CCl4, benzene, and chloroflurocarbons (CFCs), which are either toxic or damaging to the environment. The critical state is achieved when a substance is taken above its critical temperature and pressure (Tc, Pc). Above this point on a phase diagram, the gas and liquid phases become indistinguishable. The physical properties of the supercritical state (e.g., density, viscosity, solubility parameter, etc.) are intermediate between those of a gas and a liquid, and vary considerably as a function of temperature and pressure. The interest in sc CO2 specifically is related to the fact that CO2 is nontoxic and naturally occurring. The critical parameters of CO2 are moderate (Tc = 31 °C, Pc = 74 bar), which means that the supercritical state can be achieved without a disproportionate expenditure of energy. For these two reasons, there is a great deal of interest in sc CO2 as a solvent for chemical reactions. This chapter reviews the literature pertaining to free-radical reactions in sc CO2 solvent.

scholarly journals Permeation of a Range of Species through Polymer Layers under Varying Conditions of Temperature and Pressure: In Situ Measurement Methods

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1056 ◽  
Author(s):  
Bernadette Craster ◽  
Timothy Jones
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Sulfide ◽  
Elevated Temperatures ◽  
Chloride Ions ◽  
Polyphenylene Sulfide ◽  
Polymer Layers ◽  
Barrier Layers ◽  
Major Interest ◽  
Temperature And Pressure

Minimising the transport of corrosive reactants such as carbon dioxide, hydrogen sulfide and chloride ions to the surfaces of carbon steel pipes by the use of polymer barrier layers is of major interest in the oil and gas sector. In these applications, there is a requirement to assess the performance of these barrier layers although it is difficult to perform long-term predictions of barrier properties from the results of short-term measurements. New methodologies have been successfully developed to study the permeability of carbon dioxide (CO2) and hydrogen sulfide (H2S) through polymer layers under variable conditions of elevated temperatures of 100 °C and pressures of the order of 400 barg. In situ variation of the temperature and the inlet pressure of the gas (or gas mixture) allowed the activation energy and pressure dependence of the permeability to be determined without outgassing of the specimen. These methodologies have been applied to the measurement of the permeability of moulded polyphenylene sulfide (PPS) to supercritical CO2 in the presence of H2S. The diffusion coefficients of sodium chloride and potassium chloride through both PPS and polyether ether ketone (PEEK) at ambient temperature and pressure have also been measured.

THE DENSITY OF CARBON DIOXIDE

1931 ◽  
Vol 4 (3) ◽  
pp. 283-298 ◽  
Author(s):  
D. LeB. Cooper ◽  
O. Maass
Keyword(s):  
Carbon Dioxide ◽  
Molecular Weight ◽  
Pressure Range ◽  
Apparent Molecular Weight ◽  
Atomic Weight ◽  
Mean Value ◽  
Previous Communication ◽  
Temperature And Pressure

The work published in a previous communication has been extended and revised. Determinations of the density of carbon dioxide are shown for five temperatures from − 30° to + 77 °C., and over a pressure range of 760 to 250 mm. of mercury. The extrapolation of these curves to zero pressure shows a mean value for the atomic weight of carbon = 12.004 ± 0.003. A graph is included which shows the apparent molecular weight as a function of the temperature; molecular volumes have been calculated from this.The results give P.V.T. values for CO2 in the above temperature and pressure range, with an accuracy considered to be greater than available data.

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