Technique and results of experimental determination of the compressibility factor of the natural gas

2021 ◽  
pp. 35-40
Author(s):  
Denis Y. Kutovoy ◽  
Igor A. Yatsenko ◽  
Vladimir B. Yavkin ◽  
Aydar N. Mukhametov ◽  
Petr V. Lovtsov ◽  
...  
Keyword(s):  
Natural Gas ◽  
Equations Of State ◽  
Compressibility Factor ◽  
High Accuracy ◽  
State Equations ◽  
Actual Problem ◽  
Temperature Range ◽  
Relative Value ◽  
Compressibility Coefficient

The actual problem of the possibility of using the equations of state for the gas phase of natural gas at temperatures below 250 K is considered. To solve it, the compressibility coefficients of natural gas obtained experimentally with high accuracy are required. The technique was developed and experimental study was carried out of compressibility factor aiming expanding temperature range of the state equations GERG-2004 and AGA8-DC92. The proposed technique is based on the fact that to assess the applicability of the equation of state, it is sufficient to obtain the relative value of the compressibility coefficient and not to determine its absolute value. The technique does not require complex equipment and provides high accuracy. The technique was tested on nitrogen, argon, air and methane. Uncertainty of determination of the compressibility factor is not greater than 0.1 %. For two different compositions of natural gas, obtained experimental data were demonstrated that the equations of state GERG-2004 and AGA8-92DC provide uncertainty of the calculation of the compressibility coefficient within 0.1 % in the temperature range from 220 K to 250 K and pressure below 5 MPa.

Determination of Particle Densities and Line Profiles in Plasmas by Resonance Interferometry: A Feasibility Study using Computer Simulated Refractivity Data

1995 ◽  
Vol 50 (10) ◽  
pp. 902-914 ◽  
Author(s):  
C. Haas ◽  
G. Pretzier ◽  
H. Jäger
Keyword(s):  
Spectral Line ◽  
Feasibility Study ◽  
Particle Density ◽  
Detection Limits ◽  
High Accuracy ◽  
Line Profiles ◽  
Actual Problem ◽  
Density Determination

AbstractThe principles of resonance interferometry are described with regard to two applications: High accuracy particle density determination within plasmas and interferometrical determination of spectral line profiles. The usability of this technique is investigated numerically, and physical limits are given for the regions in which resonance interferometry may be employed successfully. The discussion and the results are helt general for making it possible to decide whether or not to apply this method for an actual problem. An example (an object being longitudinally homogeneous with respect to the direction of light: end-on observation) shows how to use the presented results for calculating the detection limits of the method for a given object geometry.

Evaluation of State Equations of Natural Gas in Pipeline Transportation

2012 ◽  
Vol 463-464 ◽  
pp. 936-939 ◽  
Author(s):  
Hong Yu Ren ◽  
Chang Jun Li ◽  
Guo Xie
Keyword(s):  
Numerical Methods ◽  
Natural Gas ◽  
Compressibility Factor ◽  
Computer Programs ◽  
Pipeline Transportation ◽  
Basic Form ◽  
State Equations

In current study, Sarem, CNGA, Peng-Robinson, AGA8-92DC, BWRS state equations have been researched by analyzing the basic form and developing the numerical methods of compressibility factor. An attempt has been made to develop corresponding computer programs to calculate compressibility factor with these five state equations. The computed results have been compared with Standing-Katz chart. The results show the similar trends and good agreements

scholarly journals Calculations of the complex network’s steady-state modes by brining it to equivalent open

2018 ◽  
Vol 58 ◽  
pp. 02022
Author(s):  
Dauren Akhmetbayev ◽  
Assemgul Zhantlessova ◽  
Arman Akhmetbayev
Keyword(s):  
Steady State ◽  
Equations Of State ◽  
Analytical Determination ◽  
Electrical Networks ◽  
State Equations ◽  
Inverse Form ◽  
Analytic Expressions ◽  
Equality Condition ◽  
Generalized Parameters

The paper considers the development of the idea of diakoptics as applied to the calculation of the steady-state modes of energy system’s complex electrical networks. The well-known goal of diakoptics is to obtain the equations of state for the dedicated part of the system, the study of which is much simpler than the study of the initial system and can be achieved by improving its steady state equations. Technique for dividing a complex-closed system into a set of uncomplicated subsystems was developed based on the inverse form of nodal equations. Analytic expressions for the intersection circuits obtained based on identical equality of voltage at the nodes of the system division into subsystems are proposed. Using the example of 110kV network calculation, the technique for determining the matrixes of generalized parameters of the dedicated subsystems, the sizes of which depend on the number of their broken link is shown. Analytical determination of the equality condition of the voltage of subsystems intersections nodes, allowed analyzing a complex closed network by bringing it to an equivalent open.

scholarly journals Modeling Natural Gas Compressibility Factor Using a Hybrid Group Method of Data Handling

2019 ◽  
Author(s):  
Abdolhossein Hemmati-Sarapardeh ◽  
Sassan Hajirezaie ◽  
Mohamad Reza Soltanian ◽  
Amir Mosavi ◽  
Shahab Shamshirband
Keyword(s):  
Natural Gas ◽  
Equations Of State ◽  
Compressibility Factor ◽  
Absolute Error ◽  
Group Method ◽  
Data Handling ◽  
Hydrocarbon Reservoir ◽  
Compression And Expansion ◽  
Natural Gas Transport ◽  
Gas Compressibility

A Natural gas is increasingly being sought after as a vital source of energy, given that its production is very cheap and does not cause the same environmental harms that other resources, such as coal combustion, do. Understanding and characterizing the behavior of natural gas is essential in hydrocarbon reservoir engineering, natural gas transport, and process. Natural gas compressibility factor, as a critical parameter, defines the compression and expansion characteristics of natural gas under different conditions. In this study, a simple second-order polynomial model based on the group method of data handling (GMDH) is presented to determine the compressibility factor of different natural gases at different conditions, using corresponding state principles. The accuracy of the model evaluated through graphical and statistical analyses. The results show that the model is capable of predicting natural gas compressibility with an average absolute error of only 2.88%, a root means square of 0.03, and a regression coefficient of 0.92. The performance of the developed model compared to widely known, previously published equations of state (EOSs) and correlations, and the precision of the results demonstrates its superiority over all other correlations and EOSs.

scholarly journals The effect of hydrogen on the physical properties of natural gas and the metrological characteristics of its metering systems

2020 ◽  
pp. 45-50
Author(s):  
A. A. Stetsenko ◽  
S. D. Nedzelsky ◽  
V. A. Naumenko
Keyword(s):  
Natural Gas ◽  
Physical Properties ◽  
High Pressures ◽  
Compressibility Factor ◽  
Metrological Characteristics ◽  
Physical Parameters ◽  
Gas Mixture ◽  
The Impact ◽  
Accuracy And Repeatability

Given the promise of the concept of using a mixture of hydrogen and natural gas as an energy source, studies were conducted in the following areas: determination of the effect of hydrogen impurities on the physical properties of natural gas; study of the effect of adding hydrogen to natural gas on the metrological characteristics of its consumption metering systems. To solve these problems, the following was carried out: determination of the dependence of the physical parameters of natural gas on the percentage of hydrogen in its composition: determination of the permissible fraction (permissible concentration) of hydrogen in natural gas in modern gas transmission and gas consuming systems. study of the effect of hydrogen additions on the metrological characteristics of measuring instruments and gas commercial metering systems. To conduct objective research and modeling, natural gas samples having different component composition were prepared. An analysis of the physical properties of these gases was carried out — their physical parameters were calculated: adiabatic index and sound velocity, density, compressibility factor, higher calorific value and Wobbe number. Based on these samples, modeling was performed — the physical parameters of the gases were calculated by adding hydrogen at different concentrations (from 2 to 23 %). Based on the research results, the following conclusions are made: When hydrogen is added to natural gas in an amount of from 2 to 10 %, the physical parameters of the resulting mixture change slightly (within acceptable limits), therefore, the addition of hydrogen to natural gas in an amount of up to 10 % allows the use of existing gas transmission and gas-consuming systems without any reconstructions, improvements, changes in algorithms for calculating the physical parameters of the gas mixture and calculating (volume) volumetric flow for commercial accounting. The impact on gas meters of consumers will be within the acceptable ranges of accuracy and repeatability and, therefore, will not require the cost of updating the meters. The addition of up to 25 % hydrogen by volume does not require a radical new technology of burners and gas transmission systems. Safety will not be compromised by adding 25 % hydrogen by volume to the natural gas network. Changes in the physical properties in the gas mixture have a number of disadvantages, but, in the aggregate, they do not pose any additional safety risk. The addition of hydrogen in a volume of more than 25 %, as well as the use of the mixture at high pressures, requires additional research and the development of new algorithms.

Comparison of Methods for the Sulfur Compounds and Elemental Sulfur Analysis in High-Sulfur Natural Gas

2013 ◽  
Vol 712-715 ◽  
pp. 688-700
Author(s):  
Qin Luo ◽  
Zhen Quan Tu ◽  
Zhong Li Ji ◽  
Xue Lan Xiao ◽  
Hong Gang Chang ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
Natural Gas ◽  
Elemental Sulfur ◽  
High Accuracy ◽  
Sulfur Compounds ◽  
Sulfide Content ◽  
Good Repeatability ◽  
Hydrogen Sulfide Content ◽  
Gas Fields

Some gas fields with high hydrogen sulfide content, such as Luojiazhai, Dukouhe and Puguang Gas Fields, are found in Northeast Sichuan. For exploring and utilizing high sulfur natural gas reservoirs, it is essential to quantificational analysis of sulfur compounds and elemental sulfur in high sulfur natural gas. Determination of hydrogen sulfide content in natural gas with a laser method has many advantages, including on-site measurement, fast response, wide application scope, high accuracy, high reliability, and low maintenance. When the hydrogen sulfide concentration is 1% to 20%, the relative deviation of the analysis value to the standard value is less than 3% with repeatability of less than 1%. Determination of sulfur compounds in natural gas by gas chromatograph with sulfur chemiluminescence detector (SCD) also has many advantages, such as it is simple, fast, accurate and free from interference of most sample matrixes. The analysis method has good repeatability with lower limit of detection. Since SCD has liner equimolar response to sulfur atom, only one reference gas mixture of sulfur compound is used as external standard calibration. Determination of total sulfur content in natural gas with oxidative microcoulometry method has good repeatability and high accuracy. Determination of elemental sulfur by liquid chromatography has repeatability better than 3%, the detection limit is 10mg/m3, and recovery rate of over 90%, and is applicable for determination of elemental sulfur content in high sulfur natural gas.

scholarly journals COMPARATIVE STUDY OF EMPIRICAL CORRELATIONS AND EQUATIONS OF STATE EFFECTIVENESS FOR COMPRESSIBILITY FACTOR OF NATURAL GAS DETERMINATION

2021 ◽  
Vol 18 (38) ◽  
pp. 188-213
Author(s):  
Victor L. MALYSHEV ◽  
Yana F. NURGALIEVA ◽  
Elena F. MOISEEVA
Keyword(s):  
Equation Of State ◽  
Natural Gas ◽  
Equations Of State ◽  
Compressibility Factor ◽  
Gas Mixtures ◽  
Empirical Correlations ◽  
Shift Parameter ◽  
Reduced Pressure ◽  
Absolute Relative Error ◽  
Average Absolute Relative Error

Introduction: Today, there are four main groups of methods for calculating the compressibility factor of natural gas: experimental measurements, equations of state, empirical correlations, modern methods based on genetic algorithms, neural networks, atomistic modeling (Monte Carlo method and molecular dynamics). A correctly chosen method can improve the accuracy of calculating gas reserves and predicting its production and processing. Aim: To find the optimal methods for calculating the z-factor following the characteristic thermobaric conditions. Methods: To determine the best method for calculating the compressibility factor, the effectiveness of using various empirical correlations and equations of state to predict the compressibility factor of hydrocarbon systems (reservoir gases and separation gases) of various compositions were evaluated by comparing numerical results with experimental data. Results and Discussion: Based on 824 experimental values of the compressibility factor for 235 various gas mixtures in the pressure range from 0.1 to 94 MPa and temperatures from 273 to 437 K, the optimal equation of state and empirical correlation dependence for accurate z-factor prediction was found. It is shown that for all gas mixtures the Peng-Robinson equation of state with the shift parameter and Brusilovsky equation of state allow achieving best results. For these methods, the average absolute relative error does not exceed 2%. Among the correlation dependences, the best results are shown by the Sanjari and Nemati Lay; Heidaryan, Moghadasi and Rahimi correlations with an error not exceeding 3%. Conclusions: It was found that for the proposed methods, the reduced pressure has a more significant effect on the accuracy of the calculated values than the reduced temperature. It is shown that when studying acid gas mixtures with a carbon dioxide content of more than 10%, the equations of state better describe the phase behavior of the system in comparison with empirical correlations.

THE FACTORS OF CAREER SELF-DETERMINATION OF STUDENTS OF HIGHER EDUCATION INSTITUTIONS

2019 ◽  
Vol 7 (1) ◽  
pp. 9-20
Author(s):  
Inna Yeung
Keyword(s):  
Higher Education ◽  
Higher Education Institutions ◽  
Well Being ◽  
Young Person ◽  
Self Determination ◽  
Full Time ◽  
Actual Problem ◽  
The Third ◽  
The Right

Choice of profession is a social phenomenon that every person has to face in life. Numerous studies convince us that not only the well-being of a person depends on the chosen work, but also his attitude to himself and life in general, therefore, the right and timely professional choice is very important. Research about factors of career self-determination of students of higher education institutions in Ukraine shows that self-determination is an important factor in the socialization of young person, and the factors that determine students' career choices become an actual problem of nowadays. The present study involved full-time and part-time students of Institute of Philology and Mass Communications of Open International University of Human Development "Ukraine" in order to examine the factors of career self-determination of students of higher education institutions (N=189). Diagnostic factors of career self-determination of students studying in the third and fourth year were carried out using the author's questionnaire. Processing of obtained data was carried out using the Excel 2010 program; factorial and comparative analysis were applied. Results of the study showed that initial stage of career self-determination falls down on the third and fourth studying year at the university, when an image of future career and career orientations begin to form. At the same time, the content of career self-determination in this period is contradictory and uncertain, therefore, the implementation of pedagogical support of this process among students is effective.

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