Vapor Pressure Studies Involving Solutions in Light and Heavy Waters. II. The Vapor Pressure of Heavy Water and the Separation Factor of the Mixed Waters

Combs, R. L.; Googin, J.M.; Smith, Howard G.

doi:10.1021/j150521a016

Cited by 29 publications

(15 citation statements)

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“…The gas flow before the MFC was demonstrated to be saturated by a humidity probe (Vaisala, HMP 230). The H 2 O/D 2 O concentrations were calculated by measuring the pressure before the MFC and the temperature of the thermostated Dreschel bottle, giving the H 2 O concentration via its known vapor pressure. , The temperature of the Dreschel bottle was close to or slightly below room temperature. The possibility of H 2 O/D 2 O being lost to the wall of the mixing manifold/reaction cell was investigated by measuring the H 2 O concentration using a gas chromatograph fitted with a calibrated pulsed discharge helium ionization detector (PDHID). , …”

Section: Methodsmentioning

confidence: 99%

Reaction of CH with H₂O: Temperature Dependence and Isotope Effect

et al. 1999

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The reactions of CH(ν=0) and CD(ν=0) radicals with H2O and D2O were investigated in the temperature range between 291 and 723 K. The reactions of CH(ν=1) and CD(ν=1,2) with H2O and D2O were studied at 293 K. CH(D) radicals were generated by multiphoton dissociation of CH(D)Br3 using pulsed laser photolysis and the resulting CH(D) time profiles were monitored by laser induced fluorescence. The reactions of CH(D) in the ν = 0 state exhibit a negative temperature dependence and are independent of total pressure between 20 and 200 Torr at room temperature. The rate coefficients can be fitted over the experimental temperature range by the following expressions: k(T)CH+H 2 0 = (1.56 ± 0.25) × 10-11(T/298)-1.42 ± 0.31 cm3 molecule-1 s-1; k(T)CH+D 2 0 = (1.49 ± 0.25) × 10-11(T/298)-1.04 ± 0.29 cm3 molecule-1 s-1; k(T)CD+H 2 0 = (1.38 ± 0.21) × 10-11(T/298)-1.16 ± 0.25 cm3 molecule-1 s-1; k(T)CD+D 2 0 = (1.71 ± 0.28) × 10-11(T/298)-1.13 ± 0.32 cm3 molecule-1 s-1. The errors on the parameters correspond to ±1 σ standard deviation from nonlinear least-squares fitting, and the data were weighted by 1/σ2 using a σ of 20%. Deuteration of either the CH radical or H2O has no discernible effect on the kinetics of the reaction, suggesting formation of an intermediate complex prior to the insertion of CH(D) into the OH(D) bond. Rate coefficients for CH(ν=1) and CD(ν=1,2) were found to be faster than those for the radicals in the vibrational ground state. The results are compared with previous experimental and theoretical studies, and the mechanism is discussed.

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Section: Methodsmentioning

confidence: 99%

Reaction of CH with H₂O: Temperature Dependence and Isotope Effect

et al. 1999

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“…These runs allow one to establish the small error or deviation (less than 3% in the range of 80-110 C) incurred while using the CREC-VL-Cell to determine P v sat-W . [41] One should note that the very modest oxygen solubilities can be neglected in the P v sat-W measurements, as justified in Appendix C. Runs were developed with the CREC-VL-Cell using pure octane and pure water. Observed deviations from the literature [38] and Aspen-Hysys reported data were less than 5% for pure octane and 1% for water in the 40-120 C range, respectively.…”

Section: Raw Data Corrected Data Uncertainties T ( C)mentioning

confidence: 99%

Synthetic naphtha recovery from water streams: Vapour‐liquid–liquid equilibrium (VLLE) studies in a dynamic VL‐cell unit with high intensity mixing

et al. 2021

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This work describes vapour pressure measurements of a water/synthetic naphtha mixture using a dynamic CREC-VL-Cell, designed to obtain reliable vapour measurements (P v sat,i ). The CREC-VL-Cell is used to measure vapour pressures for immiscible or partially miscible liquids, given its high multiphase mixing capability. Runs in the CREC-VL-Cell involve a dynamic method, operating with a set heating ramp, with continuous tracking of both saturation vapour pressure and temperature within the cell. This system allows for the establishment equilibrium vapour pressures, in a recommended 50-120 C range, emulating the conditions of the naphtha recovery in oil sand processes.Results obtained in the CREC-VL-Cell at 1080 rpm are validated using data from Aspen-Hysys with a Peng-Robinson fluid package for pure octane and water. On the other hand, using a 2.5 wt.% and 4 wt.% synthetic naphtha in 97.5 wt.% water blend, experimental data shows partial agreement with the Aspen-Hysys Peng-Robinson fluid package predictions, demonstrating the value of the experimental vapour-liquid-liquid (VLL) data obtained in the CREC-VL-Cell.

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“…The samples were vacuum distilled, and the water was collected in a cold trap. The isotopic compositions of the various water samples were determined by the falling-drop method of Combs, Googin, and Smith (10). Steel tubing was used for these runs since it provided the most convenient form for plating, for obtaining a large surface area, and for physically supporting the samples in the reaction flask.…”

Section: Methodsmentioning

confidence: 99%

The Separation of Hydrogen and Deuterium by the Reaction of Iron with Water

Smith¹,

Thomas²,

Posey³

1959

J. Electrochem. Soc.

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In the decomposition of water bY reaction with iron, as in the electrolysis of water, the residual water is enriched in deuterium. Since the separation factor is an inverse function of the temperature, an attempt was made to increase the reaction rate at low temperatures. Introduction of cathodic surfaces by partial plating of cathodic impurities on steel increased the reaction rate by a factor of 2 to 4 at 98~176 Separation factors from 4.8 to 6.1 were observed for the chemical reaction of these partially plated samples with water. In electrolysis experiments vigorous agitation of the electrolyte caused an increase in the separation factor.An important part of the development of nuclear power is the procurement of heavy water which is used as a moderator in some types of nuclear reactors (1). Since the natural concentration of deuterium in water is approximately 1 part in 7000 and since separation factors are generally small for isotope separation processes, it is necessary in the initial concentration stages to process very large quantities of water (2). One of the largest separation factors is obtained in the electrolysis of water. However, the energy cost is high, and the method is practical economically only when a market exists for electrolytic hydrogen or when the method is used for the final concentration of water which has been enriched by a less expensive process (2).Separation of the isotopes is obtained in the direct chemical reaction of a variety of metals with water or steam (3-5). Smith and Posey (6) reported separation factors of 3.2 to 1.4 for the reaction between iron and steam at 118~176The reaction rate in this temperature range is low for a practical production technique. Moreover, the commercial production of hydrogen by the reaction between iron and steam requires temperatures of 800~176 (7). Since the separation factor is an inverse function of the temperature (8), temperature requirements for a useful separation factor and a useful rate in the reaction of metals with water or steam appear to be mutually exclusive. The principle of sacrificial corrosion protection suggested the possibility that the reaction rate might be increased without increasing the temperature, so that the advantage of the larger separation factor at the lower temperatures could be retained. The present paper discusses reaction rates and separation factors in the direct chemical reaction of water with iron samples some of which had plated on a portion of their surfaces a variety of cathodic materials. The effect of vigorous stirring on the concentration gradient at the cathode also is discussed.

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Vapor Pressure Studies Involving Solutions in Light and Heavy Waters. II. The Vapor Pressure of Heavy Water and the Separation Factor of the Mixed Waters

Cited by 29 publications

References 0 publications

Reaction of CH with H₂O: Temperature Dependence and Isotope Effect

Reaction of CH with H₂O: Temperature Dependence and Isotope Effect

Synthetic naphtha recovery from water streams: Vapour‐liquid–liquid equilibrium (VLLE) studies in a dynamic VL‐cell unit with high intensity mixing

The Separation of Hydrogen and Deuterium by the Reaction of Iron with Water

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Vapor Pressure Studies Involving Solutions in Light and Heavy Waters. II. The Vapor Pressure of Heavy Water and the Separation Factor of the Mixed Waters

Cited by 29 publications

References 0 publications

Reaction of CH with H2O: Temperature Dependence and Isotope Effect

Reaction of CH with H2O: Temperature Dependence and Isotope Effect

Synthetic naphtha recovery from water streams: Vapour‐liquid–liquid equilibrium (VLLE) studies in a dynamic VL‐cell unit with high intensity mixing

The Separation of Hydrogen and Deuterium by the Reaction of Iron with Water

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Reaction of CH with H₂O: Temperature Dependence and Isotope Effect

Reaction of CH with H₂O: Temperature Dependence and Isotope Effect