Evaluating the phase equilibria of liquid water+natural gas mixtures using cubic equations of state with asymmetric mixing rules

2011 ◽  
Vol 302 (1-2) ◽  
pp. 179-189 ◽  
Author(s):  
P. Reshadi ◽  
Kh. Nasrifar ◽  
M. Moshfeghian
Keyword(s):  
Natural Gas ◽  
Phase Equilibria ◽  
Liquid Water ◽  
Equations Of State ◽  
Gas Mixtures ◽  
Mixing Rules

Measurement of Decompression Wave Speed in Rich Gas Mixtures at High Pressures (370 bars) Using a Specialized Rupture Tube

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
K. K. Botros ◽  
J. Geerligs ◽  
R. J. Eiber
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Wave Speed ◽  
High Pressures ◽  
Equations Of State ◽  
Gas Mixtures ◽  
Internal Diameter ◽  
Decompression Wave ◽  
Predicted Values ◽  
Fracture Arrest

Measurements of decompression wave speed in conventional and rich natural gas mixtures following rupture of a high-pressure pipe have been conducted. A high-pressure stainless steel rupture tube (internal diameter=38.1 mm and 42 m long) has been constructed and instrumented with 16 high frequency-response pressure transducers mounted very close to the rupture end and along the length of the tube to capture the pressure-time traces of the decompression wave. Tests were conducted for initial pressures of 33–37 MPa-a and a temperature range of 21–68°C. The experimentally determined decompression wave speeds were compared with both GASDECOM and PIPEDECOM predictions with and without nonequilibrium condensation delays at phase crossing. The interception points of the isentropes representing the decompression process with the corresponding phase envelope of each mixture were correlated with the respective plateaus observed in the decompression wave speed profiles. Additionally, speeds of sound in the undisturbed gas mixtures at the initial pressures and temperatures were compared with predictions by five equations of state, namely, BWRS, AGA-8, Peng–Robinson, Soave–Redlich–Kwong, and Groupe Européen de Recherches Gaziéres. The measured gas decompression curves were used to predict the fracture arrest toughness needed to assure fracture control in natural gas pipelines. The rupture tube test results have shown that the Charpy fracture arrest values predicted using GASEDCOM are within +7% (conservative) and −11% (nonconservative) of the rupture tube predicted values. Similarly, PIPEDECOM with no temperature delay provides fracture arrest values that are within +13% and −20% of the rupture tube predicted values, while PIPEDECOM with a 1°C temperature delay provides fracture arrest values that are within 0% and −20% of the rupture tube predicted values. Ideally, it would be better if the predicted values by the equations of state were above the rupture tube predicted values to make the predictions conservative but that was not always the case.

scholarly journals Decompression of hydrogen—natural gas mixtures in high-pressure pipelines: CFD modelling using different equations of state

2019 ◽  
Vol 44 (14) ◽  
pp. 7428-7437 ◽  
Author(s):  
Bin Liu ◽  
Xiong Liu ◽  
Cheng Lu ◽  
Ajit Godbole ◽  
Guillaume Michal ◽  
...  
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Equations Of State ◽  
Gas Mixtures ◽  
Cfd Modelling

scholarly journals Comparative Study of Equations of State for the Dew Curves Calculation in High Pressure Natural Gas Mixtures. [Estudio Comparativo de Ecuaciones de Estado para el Cálculo de Curvas de Rocío en Mezclas de Gas Natural a Alta Presión]

2018 ◽  
Vol 11 (1) ◽  
pp. 152-164
Author(s):  
Natalia Prieto Jiménez ◽  
Germán González Silva
Keyword(s):  
Experimental Data ◽  
Natural Gas ◽  
High Pressures ◽  
Equations Of State ◽  
Absolute Error ◽  
Gas Mixtures ◽  
Synthetic Natural Gas ◽  
Gas Processing ◽  
Processing Plants ◽  
Correct Estimation

he success during the operation of natural gas processing plants depends on the correct estimation of thermodynamic properties of the system. This paper calculates the equilibrium curves of real and synthetic natural gas mixtures means of three Equations of State (EOS). These equilibrium curves were constructed and compared with experimental data found in the literature covered. The results showed that, above 4 MPa the Peng-Robinson equation presented a considerable deviation with respect to the experimental data, reaching an absolute error of 4.36%; therefore, the GERG2008 equation is recommended for systems that operate at high pressures when the components present in the mixture apply.Keywords:Gas Mixtures, Dew curves, Equations of State; Peng-Robinson, Soave-Redlich-Kwong, GERG2008.ResumenEl éxito durante la operación de plantas de tratamiento de gas natural depende de la correcta estimación de las propiedades termodinámicas del sistema. Este artículo calcula las curvas de equilibrio de mezclas de gas natural reales y sintéticas por medio de tres ecuaciones de estado (EOS). Estas curvas de equilibrio fueron construidas y comparadas con datos experimentales presentes en la literatura. Los resultados mostraron que, por encima de 4 MPa la ecuación de Peng-Robinson presentó una desviación considerable con respecto a los datos experimentales, alcanzando un error absoluto de 4,36%; por lo cual se recomienda la ecuación de GERG2008 para sistemas que operen a altas presiones cuando los componentes presentes en la mezcla apliquen.Palabras clave:  Mezclas de gas, Curvas de rocío, Ecuaciones de estado, Peng-Robinson, Soave-Redlich-Kwong, GERG2008.ResumoO sucesso na operação de usinas de tratamento de gás natural depende da correta estimação das propriedades termodinâmicas do sistema. Este artigo calcula as curvas de equilíbrio de misturas de gás natural reais e sintéticas por meio de três equações de estado (EOS). As curvas de equilíbrio foram construídas e comparadas com dados experimentais presentes na literatura. Os resultados mostraram que, acima de 4 Mpa a equação de Peng-Robinson apresentou um desvio considerável em relação aos dados experimentais, atingindo um erro absoluto de 4,36%; por tanto, é recomendável a equação de GERG2008 para sistemas que operam em alta pressão quando os componentes presentes no sistema apliquem.Palavras-chave:Misturas de gás, Curvas de orvalho, Equações de estado, Peng-Robinson, Soave-Redlich-Kwong, GERG2008. 

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