Showing papers in "Journal of Chemical & Engineering Data in 1978"

Liquid-vapor equilibriums at 270.00 K for systems containing nitrogen, methane, and carbon dioxide

Abstract: To provide data needed for the low-temperature, high-pressure processing of natural gas, the Colorado School of Mines measured liquid-vapor equilibria for the binary systems nitrogen-carbon dioxide and methane-carbon dioxide and for the ternary system nitrogen-methane-carbon dioxide at 270.00/sup 0/ K and pressures of 23-122 atm. The equations of state chosen for study were the modified Redlich-Kwong equations and the modified van der Waals equation proposed by Peng and Robinson. The Peng-Robinson relation most closely represented the experimental data for two binary systems; predictions of the ternary system, however, proved unsatisfactory in all regions near the critical point.

Vapor-liquid equilibrium of the methane-carbon dioxide system at low temperatures

Abstract: This study reports the bubble-point compositions in the low-temperature region of the methane-carbon dioxide phase diagram. Liquid compositions in equilibrium with vapor were measured as a function of pressure on isotherms at -65.00/sup 0/, -81.40/sup 0/, -94.00/sup 0/, -112,00/sup 0/, -130.00/sup 0/, -148.00/sup 0/, and -184.00/sup 0/F (-53.89/sup 0/, -63.00/sup 0/, -70.00/sup 0/, -80.00/sup 0/, -90.00/sup 0/, -100.00/sup 0/, and -120.00/sup 0/C). The smoothed results were combined with previous dew-point data to provide tables and plots of isobaric and isothermal K values. The experimental method used was the vapor-recycle method in a temperature-controlled equilibrium cell with chromatographic analysis of the phases. (12 refs.)

Solubility and diffusivity of gases in aqueous solutions of amines

Abstract: Solubilltles of N20, C2H4, and C2H2 and dlffuslvlty of N20 In various aqueous solutions of amines (MEA, DEA, TEA, MIPA, DIPA, and EDA) were measured at 25 OC and I atm of pressure. For these present systems, solubllity and dlffuslvlty data could not be correlated by suitable correlations. The best ways to estimate solubility and dlffusivily of C02 in aqueous solutions of amines may be log (a/a,)co, = log (~/Q,)N,o and (D/D,)co, = ( D/Dw)N,O, respectively, using the Corresponding data for N20.

Pressure-temperature relationship for decomposition of sodium bicarbonate from 200 to 600.degree.F

Abstract: The equilibrium dissociation pressure of initially dry sodium bicarbonate (nahcolite) was experimentally determined between 200 and 600/sup 0/F. It was found necessary to use a constant ratio of initial gas volume to solid nahcolite volume, V/sub g//V/sub s/, to obtain a unique pressure--temperature curve. Such pressure--temperature relationships were measured for three values of V/sub g//V/sub s/, each curve showing three points of discontinuous slope. For V/sub g//V/sub s/ = 1, the pressure exceeded 6000 psia above 487/sup 0/F. Since the Green River oil shale formation in Colorado contains both beds and isolated nodules of nahcolite, the pressure developed by heating nahcolite may be a factor in developing porosity and permeability during an in situ thermal process for producing shale oil.

Solubility of hydrogen in toluene at elevated temperatures and pressures

Abstract: Solubility of hydrogen in a number of organic liquid solvents has been reported in the literature. Simnick et al. (7) reported a survey of the data which showed that past work was mostly limited to temperatures below 200 OC. Investigations of Connolly and co-workers ( 7) and Grayson and Streed (2) were the major exceptions. Recent intensified development of hydrotreating processes has heightened interest in data at elevated temperatures and pressures. In this work we report vapor-liquid equilibrium in hydrogen/toluene mixtures at temperatures of 190-300 OC and pressures 20-250 atm. The present study is a continuation of our investigation of gas-liquid equilibria at elevated temperatures and pressures (570).

Heats of formation and bond dissociation energies of some simple sulfur- and halogen-containing molecules

Abstract: Chlorine (77), bromine (22), and fluorine ( 17, 18) chemistry play an important role in the chemistry of the stratosphere. Sulfur compounds are also known to be important constituents of the atmosphere, and chemistry involving sulfur species (e.g., S, SO, SO2, SO3) is of vital importance in the formation of aerosols in photochemical smog and in the Jungle layer of the lower stratosphere (4, 7, 9, 12). These sulfur and halogen cycles have thus far been considered independent of one another; however, chemical reactions between these cycles may occur. In order to determine which reactions are thermodynamically favorable, the change in Gibbs free energy is required. At 0 K, AG = AHo' and therefore the change in enthalpy was

Volumetric data and virial coefficients for helium, krypton, and helium-krypton mixtures

Abstract: Volumetric data for helium, krypton, and three mixtures of helium and krypton (24.8, 49.7, and 74.6 mol % helium) were obtained by the Burnett technique. Measurements were made at temperatures of -50, 0, and 50 OC at pressures between 7 and 150 bar. Compressibility factors and vlrial coefficients are presented for the pure substances and mixtures, as are the interaction second vlrlal coefficients, B,*.