Prediction of the Distillation Curve and Vapor Pressure of Alcohol–Gasoline Blends Using Pseudocomponents and an Equation of State

2020 ◽  
Vol 59 (17) ◽  
pp. 8361-8373 ◽  
Author(s):  
Joseph R. Vella ◽  
Bennett D. Marshall
Keyword(s):  
Equation Of State ◽  
Vapor Pressure ◽  
Distillation Curve

An Engineering Calculation Method for Multi-Component Stagnant Droplet Evaporation With Finite Diffusivity

1994 ◽  
Author(s):  
J. S. Chin
Keyword(s):  
Heat Transfer ◽  
Diffusion Coefficient ◽  
Liquid Phase ◽  
Vapor Pressure ◽  
Molecular Mass ◽  
Calculation Method ◽  
Engineering Calculation ◽  
Droplet Evaporation ◽  
Diffusion Resistance ◽  
Distillation Curve

A practical engineering calculation method has been formulated for commercial multicomponent fuel stagnant droplet evaporation with variable finite mass and thermal diffusivity. Instead of solving the transient liquid phase mass and heat transfer partial differential equation set, a totally different approach is used. With zero or infinite mass diffusion resistance in liquid phase, it is possible to obtain vapor pressure and vapor molecular mass based on the distillation curve of these turbine fuels. It is determined that Peclet number (Pef) is a suitable parameter to represent the mass diffusion resistance in liquid phase. The vapor pressure and vapor molecular mass at constant finite Pef is expressed as a function of finite Pef, vapor pressure, and molecular mass at zero Pef and infinite Pef. At any time step, with variable finite Pef, the above equation is still valid, and PFsPef=∞, PFsPef=0, MfvPef=∞, MfvPef=0 are calculated from PFsPef≡∞, PFsPef≡0, MfvPef≡∞, MfvPef≡0, thus PFs and Mfv can be determined in a global way which eventually is based on the distillation curve of fuel. The explicit solution of transient heat transfer equation is used to have droplet surface temperature and droplet average temperature as a function of surface Nusselt number and non-dimensional time. The effect of varying com position of multi-component fuel evaporation is taken into account by expressing the properties as a function of molecular mass, acentric factor, critical temperature, and critical pressure. A specific calculation method is developed for liquid fuel diffusion coefficient, also special care is taken to calculate the binary diffusion coefficient of fuel vapor-air in gaseous phase. The effect of Stefan flow and natural convection has been included. The predictions from the present evaporation model for different turbine fuels under very wide temperature ranges have been compared with experimental data with good agreement.

Vapor pressure of 11 alkylbenzenes in the range 10−3 – 280 torr, correlation by equation of state

1993 ◽  
Vol 87 (1) ◽  
pp. 133-152 ◽  
Author(s):  
H. Kasehgari ◽  
I. Mokbel ◽  
C. Viton ◽  
J. Jose
Keyword(s):  
Equation Of State ◽  
Vapor Pressure

Semiempirical Vapor Pressure Relation Based on Dieterici's Equation of State

1959 ◽  
Vol 51 (3) ◽  
pp. 329-331 ◽  
Author(s):  
Jerome Erpenbeck ◽  
Donald Miller
Keyword(s):  
Equation Of State ◽  
Vapor Pressure

scholarly journals Modeling the properties of Kukersite shale gasoline

2021 ◽  
Author(s):  
Parsa Mozaffari ◽  
zachariah Steven baird ◽  
oliver järvik
Keyword(s):  
Experimental Data ◽  
Equation Of State ◽  
Vapor Pressure ◽  
Prediction Model ◽  
Boiling Point ◽  
Gasoline Fraction ◽  
Shale Oil ◽  
Property Prediction ◽  
Density Data ◽  
Do So

Based on new experimental data for Kukersite shale oil, it is now possible to develop a property prediction model for the gasoline fraction of shale oil. Such a model was created based on estimation of the composition along with experimental boiling point and density data. First, correlations were developed to estimate the composition of a Kukersite shale gasoline sample based on the boiling point and density of narrow fractions. The estimated composition was then used with the PC-SAFT equation of state to calculate the properties of shale gasoline. To do so, correlations were developed to predict the PC-SAFT parameters of the various classes of compounds present in Kukersite shale gasoline. The utility of this model was shown by predicting the vapor pressure of various portions of the shale gasoline.

scholarly journals A New Four-Parameter Cubic Equation of State for Predicting Fluid Phase Behavior

2019 ◽  
Author(s):  
zhiren he
Keyword(s):  
Heat Capacity ◽  
Equation Of State ◽  
Vapor Pressure ◽  
Saturated Vapor ◽  
Liquid Density ◽  
Saturated Liquid ◽  
Cubic Equation ◽  
Liquid Heat ◽  
Entropy Of Vaporization ◽  
Saturated Liquid Density

<p>A new four-parameter cubic equation of state (EoS) is generated by incorporating the critical compressibility factor (Z<sub>c</sub>) apart from the critical pressure (P<sub>c</sub>) and temperature (T<sub>c</sub>). One free parameter in the denominator of the attractive term and two parameters in the alpha function are adjusted using the experimental data of saturated liquid density, vapor pressure, and isobaric liquid heat capacity of 48 components including hydrocarbons and non-hydrocarbons. Applying this equation of state, saturated liquid density, saturated vapor density, and vapor pressure of pure components are accurately reproduced compared with experimental values. Furthermore, the predicted properties including derivatives of alpha function, such as enthalpy of vaporization, entropy of vaporization and isobaric heat capacity of liquid, also have decent accuracy. The global average absolute relative deviation (AAD) of saturated liquid density, saturated vapor density, saturated vapor pressure, enthalpy of vaporization, entropy of vaporization, and isobaric heat capacity of liquid in a wide reduced temperature (Tr) range of subcritical region reproduced by this work are 4.33%, 4.18%, 3.19%, 2.26%, 2.27%, and 5.82%, respectively. Substantial improvement has been achieved for the isobaric liquid heat capacity calculation.</p>

Estimation of the Water Content of Sour Natural Gases

1977 ◽  
Vol 17 (04) ◽  
pp. 281-286 ◽  
Author(s):  
J.N. Robinson ◽  
E. Wichert ◽  
R.G. Moore ◽  
R.A. Heideman
Keyword(s):  
Experimental Data ◽  
Equation Of State ◽  
Vapor Pressure ◽  
Water Content ◽  
Binary Data ◽  
Western Canada ◽  
Field Calculation ◽  
Acid Gas ◽  
Natural Gases ◽  
The Difference

Abstract Equilibrium water contents of sour natural gases are predicted using the Soave modification of the Redlich-Kwong equation of state. Calculated results are compared with published experimental data and with 180 field observations that were collected from the natural gas industry of western Canada and France. Computer-generated curves are provided to enable field calculation of the equilibrium water content of sour natural gases over a greater range of conditions than is possible with other methods. Introduction Natural gases containing significant quantities of acid gas are encountered frequently in western Canada. Estimates of the water content of these sour gases are required for the design of plant and pipeline facilities. This paper describes an pipeline facilities. This paper describes an equation-of-state method for predicting water content and presents a summary of field data gathered for testing the model. Three methods are currently available for estimating the water content of sour natural gases. In the procedure outlined by the Gas Processors Suppliers Assn. (GPSA), the estimated water content of a sour gas is a molar average of the solubility of water in the hydrocarbons, hydrogen sulfide, and carbon dioxide. The water-content curves for H2S and CO2 are based on experimental data for the binary mixtures H2O-H2S and H2O-CO2, respectively. Both these binaries display liquid-liquid equilibria at temperatures and pressures common in processing applications, and the water content read for the acid gas components often corresponds to the solubility of water in a nonaqueous liquid phase rather than in a vapor phase. In general, the predicted water content of sour natural gases is predicted water content of sour natural gases is high when based on these experimental curves. Maddox presents a method similar to the GPSA procedure. The difference is that the effect of procedure. The difference is that the effect of liquid-liquid separation has been removed from the H2O-CO2 and H2O-H2S binary data by smoothing. Campbell is credited with generating the curves, which terminate at 204 atm (3,000 Psi). Use of the modified curves in the molar averaging method can be expected to result in low estimates of the water content at elevated pressures. A semi-empirical correlation based on calculated mixture properties was developed by Sharma and Campbell. This method yields satisfactory estimates of water content for sour gases having total acid gas concentrations less than 15 percent, at temperatures between 300 (80 deg. F) and 344 K (160 deg. F), and at pressures less than 136 atm (2,000 psi). The major limitation of these three methods is that there is no basis for extrapolation to high acid gas concentrations or to more extreme conditions of temperature and pressure. When an equation of state is used to estimate the water content, as we have done in this paper there is, in principle, no limitation on the range of conditions that can be considered. It has been demonstrated previously that an equation of state can be used to describe waterhydrocarbon systems and the two binary pairs H2O-CO2 and H2O-H2S. In this paper, the Soave modification of the Redlich-Kwong equation has been used to calculate the water content of sour natural gases. Comparison is made with 180 field measurements taken in western Canada and in France. THE EQUATION OF STATE Soave presented a modification of the Redlich-Kwong equation in which the coefficient a was correlated against reduced temperature and acentricity so as to match vapor-pressure data of pure components. We have used this equation to pure components. We have used this equation to describe both the liquid and vapor phases. Evelein et al. found that the vapor pressure of water was not predicted with satisfactory accuracy by the Soave correlation, and presented alternative values of a for water. SPEJ P. 281

Thermodynamics of Solutions. Equation of State and Vapor Pressure

1965 ◽  
Vol 4 (4) ◽  
pp. 369-373 ◽  
Author(s):  
Otto Redlich ◽  
F. J. Ackerman ◽  
R. D. Gunn ◽  
Max Jacobson ◽  
Silvanus Lau
Keyword(s):  
Equation Of State ◽  
Vapor Pressure ◽  
Thermodynamics Of Solutions

scholarly journals A New Four-Parameter Cubic Equation of State for Predicting Fluid Phase Behavior

2019 ◽  
Author(s):  
zhiren he
Keyword(s):  
Heat Capacity ◽  
Equation Of State ◽  
Vapor Pressure ◽  
Saturated Vapor ◽  
Liquid Density ◽  
Saturated Liquid ◽  
Cubic Equation ◽  
Liquid Heat ◽  
Entropy Of Vaporization ◽  
Saturated Liquid Density

<p>A new four-parameter cubic equation of state (EoS) is generated by incorporating the critical compressibility factor (Z<sub>c</sub>) apart from the critical pressure (P<sub>c</sub>) and temperature (T<sub>c</sub>). One free parameter in the denominator of the attractive term and two parameters in the alpha function are adjusted using the experimental data of saturated liquid density, vapor pressure, and isobaric liquid heat capacity of 48 components including hydrocarbons and non-hydrocarbons. Applying this equation of state, saturated liquid density, saturated vapor density, and vapor pressure of pure components are accurately reproduced compared with experimental values. Furthermore, the predicted properties including derivatives of alpha function, such as enthalpy of vaporization, entropy of vaporization and isobaric heat capacity of liquid, also have decent accuracy. The global average absolute relative deviation (AAD) of saturated liquid density, saturated vapor density, saturated vapor pressure, enthalpy of vaporization, entropy of vaporization, and isobaric heat capacity of liquid in a wide reduced temperature (Tr) range of subcritical region reproduced by this work are 4.33%, 4.18%, 3.19%, 2.26%, 2.27%, and 5.82%, respectively. Substantial improvement has been achieved for the isobaric liquid heat capacity calculation.</p>

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