scholarly journals Comparison of GERG-2008 and simpler EoS models in calculation of phase equilibrium and physical properties of natural gas related systems

2017 ◽  
Vol 434 ◽  
pp. 21-43 ◽  
Author(s):  
Farhad Varzandeh ◽  
Erling H. Stenby ◽  
Wei Yan
Energy ◽  
2019 ◽  
Vol 167 ◽  
pp. 235-245 ◽  
Author(s):  
Mahdi Deymi-Dashtebayaz ◽  
Amir Ebrahimi-Moghadam ◽  
Seyyed Iman Pishbin ◽  
Mahdi Pourramezan

2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
Hai-Quan Zhong ◽  
Qi-Long Yao ◽  
Yu Wang ◽  
Yu-Fa He ◽  
Zi-Han Li

Natural gas hydrate has been widely of concern due to its great potential in application to address problems including gas storage, transmission, separation techniques, and also as energy resource. Accurate prediction of hydrate formation phase equilibrium conditions is essential for the optimized design during natural gas production, processing, and transportation. In this study, a novel graphical alternating conditional expectation (ACE) algorithm was proposed to predict hydrate formation phase equilibrium conditions for sweet and sour natural gases. The accuracy and performance of the presented ACE model were evaluated using 1055 data points (688, 249, and 118 data points for sweet natural gas, CO2-CH4, and H2S-CO2-CH4 systems, respectively) collected from literature. Meanwhile, a comparative study was conducted between the ACE model and commonly used correlations, including thirteen models for sweet natural gases, three models for CO2-CH4 binary system, and seven thermodynamic models for H2S-CO2-CH4 ternary system. The obtained results indicated that the proposed ACE model produces the best results in prediction of hydrate phase equilibrium temperature for sweet natural gases and pressure for CO2-CH4 system with average absolute relative deviation (AARD) of 0.134% and 2.75%, respectively. The proposed quick and explicit ACE model also provides a better performance in prediction of hydrate phase equilibrium pressure for H2S-CO2-CH4 ternary systems with AARD=5.20% compared with seven thermodynamic methods considered in this work, except for CPA/Electrolyte/Chen–Guo combined model (AARD=4.45%).


2012 ◽  
Vol 503-504 ◽  
pp. 390-395
Author(s):  
Shang Yong Li ◽  
Yuan Hu ◽  
Gang Xie ◽  
Jun Han Li

The typical chemical reactions of metal were analyzed in this paper, and the two-phase equilibrium line calculated model was obtained. By use of the physical properties database, the design of chemical reactions and the compounds were to be determined. Through the calculating the two-phase point and three-phase point ,the predominance area phase diagram algorithm based on the physical properties database was formed, which has clear physical meaning and accuracy calculation result, and also whose result was consistent with that of the literature.


2016 ◽  
Vol 34 (16) ◽  
pp. 1431-1438 ◽  
Author(s):  
Alireza Baghban ◽  
Saman Namvarrechi ◽  
Le Thi Kim Phung ◽  
Moonyong Lee ◽  
Alireza Bahadori ◽  
...  

Author(s):  
M. C. Fernández-Feal ◽  
B. Sánchez-Fernández ◽  
L. R. Sánchez-Fernández ◽  
J. R. Pérez-Prado

Aims: To assess the composition of the Natural Gas (NG) supplied for domestic consumption through the distribution network to correlate the physical properties linked to it were to be determined in order to investigate their fluctuations. Study Design:  The samples were analyzed in accordance with the method described in the ISO 6974‑4 standard, “Natural Gas. Determination of Composition with Defined Uncertainty by Gas Chromatography”. Place and Duration of Study: Center of Technology Research, Fuels Laboratory, between January and December 2016. Methodology: Over the course of the year, a total of eighty-four samples of natural gas for domestic use were analyzed.  These were collected at a rate of one per month in seven cities in the geographical zone under study (Galicia_Spain), in which the number of users is significant. Results and Conclusion: The protocols for technical management of the Gas System have a section on quality specifications for Natural Gas at entry points to the system.  This sets limits for only three of the physical properties of natural gas: Wobbe index, superior calorific value and relative density. The figures obtained for Wobbe index, superior calorific value and relative density from the eighty-four samples studied showed that the quality of the Natural Gas distributed remained steadily within the acceptable limits throughout the whole year. The values for standard deviations bore witness to the fact that any variations did not significantly alter the quality of the Natural Gas supplied. The concentrations of the odorant, THT, were always above the recommended value of 18.0 mg/Nm3, the fluctuations noted over the course of the year were such as to make it possible to see them as excessive. In some instances, a high concentration of odorant may lead users to erroneous impressions, so that they come to think that there are leaks from the gas-pipes or even that the gas is not burning properly.


Author(s):  
Konstantinos D. Papavasileiou ◽  
Manolis Vasileiadis ◽  
Vasileios K. Michalis ◽  
Loukas D. Peristeras ◽  
Ioannis G. Economou

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