Development of the translated-consistent tc-PR and tc-RK cubic equations of state for a safe and accurate prediction of volumetric, energetic and saturation properties of pure compounds in the sub- and super-critical domains

SAFT equations of state have been widely used for the determination of different thermo-physical and phase equilibria properties. In order to use these equations as predictive models it is necessary to calculate the model parameters. In this work CK-SAFT and PC-SAFT equations of state were applied for the correlation of pure compounds densities in the wide ranges of temperature and pressure (288.15?413.15 K and 0.1?60 MPa, respectively). The calculations of densities for n-hexane, n-heptane, n-octane, toluene, dichloromethane and ethanol, under high pressure conditions, were performed with the new sets of parameters determined in this paper by CK-SAFT and PC-SAFT. Very good agreement between experimental and calculated density values was achieved, having absolute average percentage deviations lower than 0.5 %.

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Joule-Thomson coefficients and inversion curves from newly developed cubic equations of state

European Journal of Chemistry ◽

10.5155/eurjchem.10.3.244-255.1883 ◽

2019 ◽

Vol 10 (3) ◽

pp. 244-255

Author(s):

Binay Prakash Akhouri ◽

Sumit Kaur

Keyword(s):

Carbon Dioxide ◽

Constant Pressure ◽

Equations Of State ◽

Accurate Prediction ◽

Temperature And Pressure ◽

And Inversion ◽

Made In

In this work, we have generalized different parametric forms of cubic equations of state (EoSs) to predict complete Joule-Thomson (J-T) inversion curves for methane at wide temperature and pressure ranges. EoSs of the Soave-Redlich-Kwong (SRK), Peng-Robinson (PR), Patel-Teja (PT), Esmaeilzadeh-Roshanfekr (ER) and the Hagtalab-Kamali-Mazloumi-Mahmoodi (HKMM) along with frequently used cohesion functions α(Tr) have been considered for plot of J-T inversion curves. The PR EoS along with different cohesion functions such as those of the Soave, Antonin Chapoy and the Tau-Sim-Tassone have been also tested for accurate prediction of the inversion curves. The four parametric EoSs of Adachi-Lu-Sugie (ALS), and Lawal-Lake-Silberberg (LLS) with their associated cohesion functions have been used for the prediction of J-T inversion curves. It has been observed that for the plot of inversion curves the LLS EoS is inadequate while the ER EoS agrees well with the previous measurements made in Laboratory. Besides, the J-T coefficient measurements from EoSs have been made for carbon dioxide and nitrogen gases at temperatures from 273.15 to 473.15 K and at pressures from 10 to 1000 atm, respectively. The uncertainties of experimental J-T coefficients data of carbon dioxide from values calculated using EoSs at constant pressure of 1 atm and 20 atm and with varying temperatures have been studied.

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