The Experts below are selected from a list of 12 Experts worldwide ranked by ideXlab platform
Brian F. Towler - One of the best experts on this subject based on the ideXlab platform.
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Rapidly Estimating Natural Gas Compressibility Factor
Journal of Natural Gas Chemistry, 2007Co-Authors: Alireza Bahadori, Saeid Mokhatab, Brian F. TowlerAbstract:Abstract Natural gases containing sour components exhibit different gas compressibility factor (Z) behavior than do sweet gases. Therefore, a new accurate method should be developed to account for these differences. Several methods are available today for calculating the Z-factor from an equation of state. However, these equations are more complex than the foregoing correlations, involving a large number of parameters, which require more complicated and longer computations. The aim of this study is to develop a simplified calculation method for a rapid estimating Z-factor for sour natural gases containing as much as 90% total acid gas. In this article, two new correlations are first presented for calculating the Pseudocritical Pressure and temperature of the gas mixture as a function of the gas specific gravity. Then, a simple correlation on the basis of the standard gas compressibility factor chart is introduced for a quick estimation of sweet gases' compressibility factor as a function of reduced Pressure and temperature. Finally, a new corrective term related to the mole fractions of carbon dioxide and hydrogen sulfide is developed.
Alireza Bahadori - One of the best experts on this subject based on the ideXlab platform.
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Rapidly Estimating Natural Gas Compressibility Factor
Journal of Natural Gas Chemistry, 2007Co-Authors: Alireza Bahadori, Saeid Mokhatab, Brian F. TowlerAbstract:Abstract Natural gases containing sour components exhibit different gas compressibility factor (Z) behavior than do sweet gases. Therefore, a new accurate method should be developed to account for these differences. Several methods are available today for calculating the Z-factor from an equation of state. However, these equations are more complex than the foregoing correlations, involving a large number of parameters, which require more complicated and longer computations. The aim of this study is to develop a simplified calculation method for a rapid estimating Z-factor for sour natural gases containing as much as 90% total acid gas. In this article, two new correlations are first presented for calculating the Pseudocritical Pressure and temperature of the gas mixture as a function of the gas specific gravity. Then, a simple correlation on the basis of the standard gas compressibility factor chart is introduced for a quick estimation of sweet gases' compressibility factor as a function of reduced Pressure and temperature. Finally, a new corrective term related to the mole fractions of carbon dioxide and hydrogen sulfide is developed.
Saeid Mokhatab - One of the best experts on this subject based on the ideXlab platform.
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Rapidly Estimating Natural Gas Compressibility Factor
Journal of Natural Gas Chemistry, 2007Co-Authors: Alireza Bahadori, Saeid Mokhatab, Brian F. TowlerAbstract:Abstract Natural gases containing sour components exhibit different gas compressibility factor (Z) behavior than do sweet gases. Therefore, a new accurate method should be developed to account for these differences. Several methods are available today for calculating the Z-factor from an equation of state. However, these equations are more complex than the foregoing correlations, involving a large number of parameters, which require more complicated and longer computations. The aim of this study is to develop a simplified calculation method for a rapid estimating Z-factor for sour natural gases containing as much as 90% total acid gas. In this article, two new correlations are first presented for calculating the Pseudocritical Pressure and temperature of the gas mixture as a function of the gas specific gravity. Then, a simple correlation on the basis of the standard gas compressibility factor chart is introduced for a quick estimation of sweet gases' compressibility factor as a function of reduced Pressure and temperature. Finally, a new corrective term related to the mole fractions of carbon dioxide and hydrogen sulfide is developed.
Ali Hernández - One of the best experts on this subject based on the ideXlab platform.
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Chapter 1 – Gas properties
Fundamentals of Gas Lift Engineering, 2016Co-Authors: Ali HernándezAbstract:A description of the hydrocarbon gases that are commonly used as lift gas in most gas lift installations is presented at the beginning of the chapter, including the compositional limits that are used to classify these gas mixtures as corrosive, sweet or sour, or capable of generating hydrate related problems. The general equation of state is presented for ideal and real gases with the use of the compressibility factor and the universal gas constant. The way in which the compressibility factor is calculated from the Pseudocritical Pressure and temperature of the lift gas mixture is presented. Dalton’s and Amagat’s laws are described and used to solve problems and find the partial Pressure of a particular pure gas in the mixture. The molecular weight of a gas mixture is determined from the mole fraction of its individual components. The specific gravity of a mixture of natural gases is defined and different methods that can be used for its calculation are presented. The following additional topics are presented: general equations for the calculation of the gas viscosity, determination of lift gas solubility in water, procedure to determine the water vapor content of a mixture of hydrocarbon gases, procedures to predict the onset of hydrates, and calculation of the gas specific heat ratio.
Lu Yan - One of the best experts on this subject based on the ideXlab platform.
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Excess molar enthalpies of ethanol–hexane, ethanol–cyclohexane and ethanol–benzene from 453.5 to 522.9 K and up to 4.5 MPa
J. Chem. Soc. Faraday Trans., 1993Co-Authors: Mario Massucci, Christopher J. Wormald, Lu YanAbstract:Flow calorimetric measurements of the excess molar enthalpy, HEm, of [0.5C2H5OH + 0.5C6H14](g), [0.5C2H5OH + 0.5C6H12](g) and [0.5C2H5OH + 0.5C6H6](g) are reported. The measurements extend over the temperature range 453.5 to 522.9 K and are at Pressures up to 4.5 MPa. Residual molar enthalpies of hexane, cyclohexane and benzene were calculated from the equation of state proposed by Kubic, and the residual molar enthalpy of ethanol was calculated from a modification of Kubic's equation proposed by Massucci and Wormald. For ethanol in its interaction with hexane or cyclohexane there is no hydrogen bonding, and the excess molar enthalpy can be fitted by applying simple one-fluid mixing rules using a pseudo-critical temperature of 345 K and a Pseudocritical Pressure of 4.65 MPa for ethanol. For ethanol–benzene the values of HEm calculated by this method are too large. Previous measurements of HEm for benzene with steam or methanol showed similar behaviour, and the difference between the experimental values of HEm and those calculated from an equation of state was attributed to association between the steam or methanol and the benzene molecules. Using a similar approach we attributed the difference between the experimental and calculated values of HEm for ethanol–benzene to weak association between the unlike molecules, and obtained a value of the equilibrium constant K12(298.15 K)= 0.2197 MPa–1 and a value of ΔH12=–14.0 kJ mol–1 for the enthalpy of the specific interaction between ethanol and benzene.
