DOCSLIB.ORG

Accurate Calculations of Compressibility Factor for Pure Gases and Gas Mixtures

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Accurate Calculations of Compressibility Factor for Pure Gases and Gas Mixtures OBEIDA, Tawfic A, AGOCO, Libya and Mining University Leoben, Austria HEINEMANN, Zoltán E., Mining University Leoben , Austria KRIEBERNEGG, Michael, Mining University Leoben, Austria Paper presented at the Sth European Conference on the Mathematics of Oil Recovery, Leoben, Austria, 3-6 Sept. 1996 ABSTRACT in non-compositional simulators. An accurate method to prediet volumetrie behavior of gas INTRODUCTION mixtures, such as in the case of underground gas storage The compressibility factor is an important property for where the in-situ gas is mixed with the injected gas, is gases to calculate volume (formation volume factor) of presented in this paper. This method accurately calculates gases and the coefficient of isothermal compressibility the compressibility (Z) factor of pure hydrocarbon, non- under given conditions (pressure, temperature). hydrocarbon gases and gas mixtures. To account for the non-additive behavior of volumes of hydrocarbon and non- It is important to calculate the Z-factor more accurately, hydrocarbon gases, correction functions were developed specially for gas mixtures, in order to predict the volumetrie from correlation of data (Z-factors) generated by the Peng- gas behavior more reasonable. In compositional simulators Robinson equation of state. The correction functions are the calculations of the Z-factor are accurate, but for every function of gas composition, pressure and temperature, so condition the cubic equation of state is solved for Z-factor. the Z-factor can be calculated explicitly from gas The solution procedure involves iterations such as in composition under different reservoir conditions. Newton Raphson method. These iterations and convergence checking procedure consumes, some times, a considerable Several comparative examples are presented to compare part of CPU time for just calculating gas properties (Z- the Z-factors calculated by the correction functions with factor). The CPU time should be used more efficiently those calculated by the Peng-Robinsion equation of state and wisely in the simulator. On the other side in the (PR-EOS) and with measured data published in the non-compositional simulators, the Z-factoi values are literature. The comparison results indicated that the average tabulated for certain gas composition and pressures and a relative deviation (ARD) is 3% for gas mixtures, 2% for linear interpolation procedure is used to calculated those pure hydrocarbon, non-hydrocarbon gases and less than Z-factor values which are not listed in the table. This 1% for pure components (methane, nitrogen, carbon procedure leads to erroneous calculations of Z-factor dioxide). A stable method of calculating Z-factor for gases specially for gas mixtures where the linear interpolations from their composition is presented. This method is iteration are no longer accurate. The calculation procedure of Z- free so the CPU time is minimized. More accurate values factor using the correlation functions presented in this paper of Z-factor can be calculated which are much better than bas two advantages: Obtaining an accurate value of Z-factor those obtained by linear interpolations. and saving CPU time for other more important calculations The correction functions can be incorporated in any non- in the simulator. compositional simulator to calculate the Z-factor directly BACKGROUND without any iterative procedures, which occur in compositional simulators during the calculations of Z-factor Some impurities such as nitrogen and carbon dioxide are by the equation of state. These functions also eliminate often existed in appreciable amounts in natural gases. The the inaccurate linear interpolations of tabulated Z-values , Z-factor for non-hydrocarbon components of natural gas specially during calculations of Z-factor for gas mixtures, in certain corresponding states differ markedly from those of hydrocarbons. This makes the non-hydrocarbon and 517 2 Accurate CalcuJations of Compressibility ECMOR V, 1996 Factor for Pure Gases and Gas Mixtures hydrocarbon components not quit additive. Eilerts, Muller T = Temperature, and Carlson I studied the compressibility of natural gas p = Pressure. and nitrogen mixtures. They proposed a method to calcuJate the Z-factor for the gas mixture by introducing a correction The additive volume correction function (Fa) is a function factor into the additive foon in Eq. l. of temperature, pressure, mole fraction of the non- hydrocarbon gas in the mixture and the mole fraction of z, =c{nZn+(l-n)Zh} (1) carbon dioxide in the non-hydrocarbon gas. The function Where: actual Z-factor for gas mixture, z". = Fa. is symmetrical with respect to xm and equals to one at X Zn = Z-factor of the nitrogen in the mixture, m equals to zero (pure hydrocarbon gas) also at xm equals ~ = Z-factor of hydrocarbon gas, to one (pure non-hydrocarbon gas) as shown in Fig. l. n = mole fraction of nitrogen in the mixture Since the function Fa. is symmetrical with respect to ~ ' it was calcuJated only for 0 < xm < 0.5 as following: Where c is an arbitrary factor to account for the fact that 2 volumes of hydrocarbon and non-hydrocarbon are not quit Fav =aO+alP+~p (3) additive. The values of the factor c were presented in Where ao' ~ and ~ are parameters function of xm which charts for different mixtures at certain pressures and can be calcuJated from Eq. 4: temperatures. ao(xm) = bo + qXm } Olds, Sage and Lacey 4 studied the effects of carbon dioxide al(xm)=CO+ClXm ; (4) on the compressibility of methane. They computed the additive-volume correction factors for few methane-carbon a2(xm) = do +d1xm dioxide mixtures at different pressures and temperatures. If~ is grater than 0.5, then ~ in Eq. 4 should be substituted To obtained the full range of mixture compositions , by (l-xJ. The parameters bo, bI' co' cl' <10 and dl are interpolations were used. function of the mole fraction of carbon dioxide in the non-hydrocarbon gas (XcOO>and they can be calculated The main disadvantages of the above method are that the from Eq. 5 to Eq. 7 as following: values of the correction factor (c) were computed for a few and limited gas mixtures using pure components such as nitrogen or carbon dioxide to be mixed withthe 1.0 1 5,......~~,....~~"T'""~~""T""~~....,.~~..., hydrocarbon gas and to obtained a fuIl range of mixtures, interpolations were the only option left to be used. In this paper a more comprehensive method is proposed to eliminate the above mentioned limitations . We propose ~ . a similar method to calculate the Z-factor for any gas ~ 1.01 ················r· ··T······......···· mixture, but instead of a constant c, a function was ~ Ol introduced to repJace the constant c as shown by Eq. 2. § ..Q METHODOLOGY ~Ol ~ 1.005 . In this section we like to present the calculation methods "Cl of the Z-factor for gas mixtures, pure hydrocarbon gases < and pure non-hydrocarbon gases. Z~factor of Gas Mixtures To calculate the Z-factor for a mixture of hydrocarbon 1~--~--~--------L-~----~ o o.z 0.4 0.6 0.8 and non-hydrocarbon gases, we propose the following equation: Mole Fraction Flue gas (Xm) Zm = Fav(T.p,Xm,xcCY).)X {ZHc(1-Xm)+ ZNHcXm} Figure 1: Additive volume correction function of methane (2) and fIue gas (87%N2) at 60T Where: Fa. = Additive volume correction function, ~c = Z- factor for the non-hydrocarbon gas bO(XC02) bOl + b02XCO + bfJ3X:o + b04X: } ~c = Z-factor for the hydrocarbon gas, = , a , Mole fraction of the non-hydrocarbon ~ = bI (XC02) = bil + bl2Xco ,+ b13X:o , gas in the mixture, (5) Xco2 = Mole fraction of CO in the non- 2 Co(Xco2) =cOl +c02Xco2 +C03X';02} hydrocarbon gas, (6) Cl (Xco2)= <u +C12Xco2 +C13X';o2 518 ECMOR V, 1996 OBEIDA, T. A.; HEINEMANN, Z.E.; KRIEBERNEGG, M. 3 Z-factor of hydrocarbon gases do(Xco2) = dOl + d02Xco2 + d03Xco2 The Z-factor of any hydrocarbon gas (dry gas or rich 2 } (7) gas) can be calculated in two steps. First, the Z-factor of dl (Xco2) = dll + d12Xco2 + d13X;o2 pure methane is calculated, then the Z-factor of the richer The parameters bOl' b02, b03' bw bil' b12, b13, cOl' c02' coo' gas can be calculated second. cII' C12' cl3' dOl' d02, <103' dil. d12, and dl3 are function of Z-Factor of pure Methane temperature and they can be calculated from Eq. 8 to Eq. The compressibility factor of pure methane can be 13 as following : 2 calculated directly by the correlation in Eq. 14 as bOl = aOl + /301 T +801T following. 2 b02 = a02 + /302 T + 802T Zet = llo + alP + ~p2 (14) (8) Where: ZCI = Z-factor of pure methane. b03 = a03 +/303T +803T2 30, al and ~ are parameters function of temperature which b04 = a04 +/304T +804T2 can be calculated from Eq. 15: 2 ao(T) = bo +b1T+b2T bll = al1 + /311T} T (9) 2 b12 = a12 +/312 ~(T)=co +c1T+c2T (15) b13 = a13 + /3l3T 2 ~(T)=do +d1T+d2T 2 bo, b., ....., d2 are constants obtained from regression. COl = <TOl + AolT+80lT } 2 Z-Factor of Natural Gas C02 =<T02 +Ào2T+802T (10) If the hydrocarbon gas is not pure methane, such as natural C03 = <T03 + Ào3T + 803T2 gases (dry and rich gases), the compressibility factor can be calculated in terms of Z-factor of methane as following: )X ZCl T T2 ZHC = Fhc(p,T,KCI (16) Cll =<Tll +All +811 } 2 Where: Fhc (p,T'~I) and ZHCare the correction function C12 <T12 + A12T + 8 T (11) = 12 and the Z-factor of the hydrocarbon gas. C13 = <T13 + A13T + 8l3T2 The correction function of hydrocarbon gases is a function of pressure, temperature and methane deviation factor (KCI)' T 2 a factor depends on the composition of the natural gas, dOl = EOI +f/JOl + POlT } which is defmed by Eq.
Recommended publications
  • Blending Hydrogen Into Natural Gas Pipeline Networks: a Review of Key Issues

    Blending Hydrogen Into Natural Gas Pipeline Networks: a Review of Key Issues

    Blending Hydrogen into Natural Gas Pipeline Networks: A Review of Key Issues M. W. Melaina, O. Antonia, and M. Penev NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency & Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. Technical Report NREL/TP-5600-51995 March 2013 Contract No. DE-AC36-08GO28308 Blending Hydrogen into Natural Gas Pipeline Networks: A Review of Key Issues M. W. Melaina, O. Antonia, and M. Penev Prepared under Task No. HT12.2010 NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency & Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. National Renewable Energy Laboratory Technical Report 15013 Denver West Parkway NREL/TP-5600-51995 Golden, Colorado 80401 March 2013 303-275-3000 • www.nrel.gov Contract No. DE-AC36-08GO28308 NOTICE This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States government or any agency thereof.
  • Atmospheric Gases Student Handout Atmospheric Gases

    Atmospheric Gases Student Handout Atmospheric Gases

    Atmospheric Gases Student Handout Atmospheric Gases Driving Question: What is our atmosphere made of? In this activity you will: 1. Explore the variety and ratio of compounds and elements that make up the Earth’s atmosphere. 2. Understand volumetric measurements of gases in the atmosphere. 3. Visually depict the composition of the atmosphere. Background Information: Understanding Concentration Measurements In this activity, we will investigate the gas composition of our planet’s atmosphere. We use percentages to represent units of gas composition. A percent (%) is equivalent to 1 part out of 100 equal units. 1% = 1 part out of 100 For smaller concentrations scientists use parts per million (ppm) to represent concentrations of gases (or pollutants) in the atmosphere). One ppm is equivalent to 1 part out of 1,000,000 if the volume being measured is separated into 1,000,000 equal units. 1 ppm = 1 part out of 1,000,000 In this activity, you will use graph paper to represent the concentration of different gases in the atmosphere. Copyright © 2011 Environmental Literacy and Inquiry Working Group at Lehigh University Atmospheric Gases Student Handout 2 Here are some examples to help visualize parts per million: The common unit mg/liter is equal to ppm concentration Four drops of ink in a 55-gallon barrel of water would produce an "ink concentration" of 1 ppm. 1 12-oz can of soda pop in a 30-meter swimming pool 1 3-oz chocolate bar on a football field Atmospheric Composition Activity You will be creating a graphic model of the atmosphere composition using the Atmospheric Composition of Clean Dry Air activity sheet.
  • Tracer Applications of Noble Gas Radionuclides in the Geosciences

    Tracer Applications of Noble Gas Radionuclides in the Geosciences

    To be published in Earth-Science Reviews Tracer Applications of Noble Gas Radionuclides in the Geosciences (August 20, 2013) Z.-T. Lua,b, P. Schlosserc,d, W.M. Smethie Jr.c, N.C. Sturchioe, T.P. Fischerf, B.M. Kennedyg, R. Purtscherth, J.P. Severinghausi, D.K. Solomonj, T. Tanhuak, R. Yokochie,l a Physics Division, Argonne National Laboratory, Argonne, Illinois, USA b Department of Physics and Enrico Fermi Institute, University of Chicago, Chicago, USA c Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York, USA d Department of Earth and Environmental Sciences and Department of Earth and Environmental Engineering, Columbia University, New York, USA e Department of Earth and Environmental Sciences, University of Illinois at Chicago, Chicago, IL, USA f Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, USA g Center for Isotope Geochemistry, Lawrence Berkeley National Laboratory, Berkeley, USA h Climate and Environmental Physics, Physics Institute, University of Bern, Bern, Switzerland i Scripps Institution of Oceanography, University of California, San Diego, USA j Department of Geology and Geophysics, University of Utah, Salt Lake City, USA k GEOMAR Helmholtz Center for Ocean Research Kiel, Marine Biogeochemistry, Kiel, Germany l Department of Geophysical Sciences, University of Chicago, Chicago, USA Abstract 81 85 39 Noble gas radionuclides, including Kr (t1/2 = 229,000 yr), Kr (t1/2 = 10.8 yr), and Ar (t1/2 = 269 yr), possess nearly ideal chemical and physical properties for studies of earth and environmental processes. Recent advances in Atom Trap Trace Analysis (ATTA), a laser-based atom counting method, have enabled routine measurements of the radiokrypton isotopes, as well as the demonstration of the ability to measure 39Ar in environmental samples.
  • An Entropy-Stable Hybrid Scheme for Simulations of Transcritical Real-Fluid

    An Entropy-Stable Hybrid Scheme for Simulations of Transcritical Real-Fluid

    Journal of Computational Physics 340 (2017) 330–357 Contents lists available at ScienceDirect Journal of Computational Physics www.elsevier.com/locate/jcp An entropy-stable hybrid scheme for simulations of transcritical real-fluid flows Peter C. Ma, Yu Lv ∗, Matthias Ihme Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA a r t i c l e i n f o a b s t r a c t Article history: A finite-volume method is developed for simulating the mixing of turbulent flows at Received 30 August 2016 transcritical conditions. Spurious pressure oscillations associated with fully conservative Received in revised form 9 March 2017 formulations are addressed by extending a double-flux model to real-fluid equations of Accepted 12 March 2017 state. An entropy-stable formulation that combines high-order non-dissipative and low- Available online 22 March 2017 order dissipative finite-volume schemes is proposed to preserve the physical realizability Keywords: of numerical solutions across large density gradients. Convexity conditions and constraints Real fluid on the application of the cubic state equation to transcritical flows are investigated, and Spurious pressure oscillations conservation properties relevant to the double-flux model are examined. The resulting Double-flux model method is applied to a series of test cases to demonstrate the capability in simulations Entropy stable of problems that are relevant for multi-species transcritical real-fluid flows. Hybrid scheme © 2017 Elsevier Inc. All rights reserved. 1. Introduction The accurate and robust simulation of transcritical real-fluid effects is crucial for many engineering applications, such as fuel injection in internal-combustion engines, rocket motors and gas turbines.
  • Equation of State for Natural Gas Systems

    Equation of State for Natural Gas Systems

    Equation of State for Natural Gas Systems. m A thesis submitted to the University of London for the Degree of Doctor of Philosophy and for the Diploma of Imperial College by Jorge Francisco Estela-Uribe. Department of Chemical Engineering and Chemical Technology Imperial College of Science, Technology and Medicine. Prince Consort Road, SW7 2BY London, United Kingdom. March 1999. Acknowledgements. I acknowledge and thank the sponsorship I received from the following institutions: Fundacion para el Futuro de Colombia, Colfiituro; Pontificia Universidad Javeriana, Seccional Cali; the Committee of Vice-Chancellors and Principal of the Universities of the United Kingdom and Ruhrgas AG. Without their economic support my stay in London and the completion of this work would have been impossible. My greatest gratitude goes to my Supervisor, Dr Martin Trusler. His expert guidance and advice were always fundamental for the success of this research. He helped me with abundant patience and undying commitment and his optimism regarding the possibilities of the project was always inspirational for me. He also worked shoulder by shoulder with me on solving a good number of experimental problems, some of them were just cases of bad luck and for some prominent ones, I was the only one to blame. Others helped me willingly as well. My labmate, Dr Andres Estrada-Alexanders, was quite helpful in the beginning of my research, and has carried on being so. He not only did do well in his role as the senior student in the laboratory, but also became a good fnend of mine. Another good friend of mine, Dr Abdel Fenghour, has always been an endless source of help and information.
  • Appendix a Basics of Landfill

    Appendix a Basics of Landfill

    APPENDIX A BASICS OF LANDFILL GAS Basics of Landfill Gas (Methane, Carbon Dioxide, Hydrogen Sulfide and Sulfides) Landfill gas is produced through bacterial decomposition, volatilization and chemical reactions. Most landfill gas is produced by bacterial decomposition that occurs when organic waste solids, food (i.e. meats, vegetables), garden waste (i.e. leaf and yardwaste), wood and paper products, are broken down by bacteria naturally present in the waste and in soils. Volatilization generates landfill gas when certain wastes change from a liquid or solid into a vapor. Chemical reactions occur when different waste materials are mixed together during disposal operations. Additionally, moisture plays a large roll in the speed of decomposition. Generally, the more moisture, the more landfill gas is generated, both during the aerobic and anaerobic conditions. Landfill Gas Production and Composition: In general, during anaerobic conditions, the composition of landfill gas is approximately 50 percent methane and 50 percent carbon dioxide with trace amounts (<1 percent) of nitrogen, oxygen, hydrogen sulfide, hydrogen, and nonmethane organic compounds (NMOCs). The more organic waste and moisture present in a landfill, the more landfill gas is produced by the bacteria during decomposition. The more chemicals disposed in a landfill, the more likely volatile organic compounds and other gasses will be produced. The Four Phases of Bacterial Decomposition: “Bacteria decompose landfill waste in four phases. The composition of the gas produced changes with each of the four phases of decomposition. Landfills often accept waste over a 20-to 30-year period, so waste in a landfill may be undergoing several phases of decomposition at once.
  • Chapter 3 3.4-2 the Compressibility Factor Equation of State

    Chapter 3 3.4-2 the Compressibility Factor Equation of State

    Chapter 3 3.4-2 The Compressibility Factor Equation of State The dimensionless compressibility factor, Z, for a gaseous species is defined as the ratio pv Z = (3.4-1) RT If the gas behaves ideally Z = 1. The extent to which Z differs from 1 is a measure of the extent to which the gas is behaving nonideally. The compressibility can be determined from experimental data where Z is plotted versus a dimensionless reduced pressure pR and reduced temperature TR, defined as pR = p/pc and TR = T/Tc In these expressions, pc and Tc denote the critical pressure and temperature, respectively. A generalized compressibility chart of the form Z = f(pR, TR) is shown in Figure 3.4-1 for 10 different gases. The solid lines represent the best curves fitted to the data. Figure 3.4-1 Generalized compressibility chart for various gases10. It can be seen from Figure 3.4-1 that the value of Z tends to unity for all temperatures as pressure approach zero and Z also approaches unity for all pressure at very high temperature. If the p, v, and T data are available in table format or computer software then you should not use the generalized compressibility chart to evaluate p, v, and T since using Z is just another approximation to the real data. 10 Moran, M. J. and Shapiro H. N., Fundamentals of Engineering Thermodynamics, Wiley, 2008, pg. 112 3-19 Example 3.4-2 ---------------------------------------------------------------------------------- A closed, rigid tank filled with water vapor, initially at 20 MPa, 520oC, is cooled until its temperature reaches 400oC.
  • Real Gases – As Opposed to a Perfect Or Ideal Gas – Exhibit Properties That Cannot Be Explained Entirely Using the Ideal Gas Law

    Real Gases – As Opposed to a Perfect Or Ideal Gas – Exhibit Properties That Cannot Be Explained Entirely Using the Ideal Gas Law

    Basic principle II Second class Dr. Arkan Jasim Hadi 1. Real gas Real gases – as opposed to a perfect or ideal gas – exhibit properties that cannot be explained entirely using the ideal gas law. To understand the behavior of real gases, the following must be taken into account: compressibility effects; variable specific heat capacity; van der Waals forces; non-equilibrium thermodynamic effects; Issues with molecular dissociation and elementary reactions with variable composition. Critical state and Reduced conditions Critical point: The point at highest temp. (Tc) and Pressure (Pc) at which a pure chemical species can exist in vapour/liquid equilibrium. The point critical is the point at which the liquid and vapour phases are not distinguishable; because of the liquid and vapour having same properties. Reduced properties of a fluid are a set of state variables normalized by the fluid's state properties at its critical point. These dimensionless thermodynamic coordinates, taken together with a substance's compressibility factor, provide the basis for the simplest form of the theorem of corresponding states The reduced pressure is defined as its actual pressure divided by its critical pressure : The reduced temperature of a fluid is its actual temperature, divided by its critical temperature: The reduced specific volume ") of a fluid is computed from the ideal gas law at the substance's critical pressure and temperature: This property is useful when the specific volume and either temperature or pressure are known, in which case the missing third property can be computed directly. 1 Basic principle II Second class Dr. Arkan Jasim Hadi In Kay's method, pseudocritical values for mixtures of gases are calculated on the assumption that each component in the mixture contributes to the pseudocritical value in the same proportion as the mol fraction of that component in the gas.
  • Natural Gas Compressibility Factor Correlation Evaluation for Niger Delta Gas Fields

    Natural Gas Compressibility Factor Correlation Evaluation for Niger Delta Gas Fields

    IOSR Journal of Electrical and Electronics Engineering (IOSR-JEEE) e-ISSN: 2278-1676,p-ISSN: 2320-3331, Volume 6, Issue 4 (Jul. - Aug. 2013), PP 01-10 www.iosrjournals.org Natural Gas Compressibility Factor Correlation Evaluation for Niger Delta Gas Fields Obuba, J*.1, Ikiesnkimama, S.S.2, Ubani, C. E.3, Ekeke, I. C.4 12Petroleum/Gas, Engineering/ University of Port Harcourt, Nigeria 3Department of Petroleum and Gas Engineering University of Port Harcourt Port Harcourt, Rivers State. 4Department of Chemical Engineering Federal University of Technology Oweri, Imo State Nigeria. Abstract: Natural gas compressibility factor (Z) is key factor in gas industry for natural gas production and transportation. This research presents a new natural gas compressibility factor correlation for Niger Delta gas fields. First, gas properties databank was developed from twenty-two (22) laboratory Gas PVT Reports from Niger Delta gas fields. Secondly, the existing natural gas compressibility factor correlations were evaluated against the developed database (comprising 22 gas reservoirs and 223 data sets). The developed new correlation was used to compute the z-factors for the four natural gas reservoir system of dry gas, solution gas, rich CO2 gas and rich condensate gas reservoirs, and the results were compared with some exiting correlations. The performances of the developed correction indicated better statistical ranking, good graph trends and best crossplots parity line when compared with correlations evaluated. From the results the new developed correlation has the least standard error and absolute error of (stdEr) of 1.461% and 1.669% for dry gas; 6.661% and 1.674% for solution; 7.758% and 6.660% for rich CO2 and 7.668% and 6.661 % for rich condensate gas reservoirs.
  • Reviewing Martian Atmospheric Noble Gas Measurements: from Martian Meteorites to Mars Missions

    Reviewing Martian Atmospheric Noble Gas Measurements: from Martian Meteorites to Mars Missions

    geosciences Review Reviewing Martian Atmospheric Noble Gas Measurements: From Martian Meteorites to Mars Missions Thomas Smith 1,* , P. M. Ranjith 1, Huaiyu He 1,2,3,* and Rixiang Zhu 1,2,3 1 State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, 19 Beitucheng Western Road, Box 9825, Beijing 100029, China; [email protected] (P.M.R.); [email protected] (R.Z.) 2 Institutions of Earth Science, Chinese Academy of Sciences, Beijing 100029, China 3 College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China * Correspondence: [email protected] (T.S.); [email protected] (H.H.) Received: 10 September 2020; Accepted: 4 November 2020; Published: 6 November 2020 Abstract: Martian meteorites are the only samples from Mars available for extensive studies in laboratories on Earth. Among the various unresolved science questions, the question of the Martian atmospheric composition, distribution, and evolution over geological time still is of high concern for the scientific community. Recent successful space missions to Mars have particularly strengthened our understanding of the loss of the primary Martian atmosphere. Noble gases are commonly used in geochemistry and cosmochemistry as tools to better unravel the properties or exchange mechanisms associated with different isotopic reservoirs in the Earth or in different planetary bodies. The relatively low abundance and chemical inertness of noble gases enable their distributions and, consequently, transfer mechanisms to be determined. In this review, we first summarize the various in situ and laboratory techniques on Mars and in Martian meteorites, respectively, for measuring noble gas abundances and isotopic ratios.
  • Thermodynamic Propertiesproperties

    Thermodynamic Propertiesproperties

    ThermodynamicThermodynamic PropertiesProperties PropertyProperty TableTable -- from direct measurement EquationEquation ofof StateState -- any equation that relates P,v, and T of a substance jump ExerciseExercise 33--1212 A bucket containing 2 liters of R-12 is left outside in the atmosphere (0.1 MPa) a) What is the R-12 temperature assuming it is in the saturated state. b) the surrounding transfer heat at the rate of 1KW to the liquid. How long will take for all R-12 vaporize? See R-12 (diclorindifluormethane) on Table A-2 SolutionSolution -- pagepage 11 Part a) From table A-2, at the saturation pressure of 0.1 MPa one finds: • Tsaturation = - 30oC 3 • vliq = 0.000672 m /kg 3 • vvap = 0.159375 m /kg • hlv = 165KJ/kg (vaporization heat) SolutionSolution -- pagepage 22 Part b) The mass of R-12 is m = Volume/vL, m = 0.002/0.000672 = 2.98 kg The vaporization energy: Evap = vap energy * mass = 165*2.98 = 492 KJ Time = Heat/Power = 492 sec or 8.2 min GASGAS PROPERTIESPROPERTIES Ideal -Gas Equation of State M PV = nR T; n = u mol Universal gas constant is given on Ru = 8.31434 kJ/kmol-K = 8.31434 kPa-m3/kmol-k = 0.0831434 bar-m3/kmol-K = 82.05 L-atm/kmol-K = 1.9858 Btu/lbmol-R = 1545.35 ft-lbf/lbmol-R = 10.73 psia-ft3/lbmol-R EExamplexample Determine the particular gas constant for air (28.97 kg/kmol) and hydrogen (2.016 kg/kmol). kJ 8.1417 kJ = Ru = kmol − K = 0.287 Rair kg M 28.97 kg − K kmol kJ 8.1417 kJ = kmol − K = 4.124 Rhydrogen kg 2.016 kg − K kmol IdealIdeal GasGas “Law”“Law” isis aa simplesimple EquationEquation ofof StateState PV = MRT Pv = RT PV = NRuT P V P V 1 1 = 2 2 T1 T2 QuestionQuestion …...…..
  • A Comprehensive Numerical Study on Effects of Natural Gas Composition on the Operation of an HCCI Engine O

    A Comprehensive Numerical Study on Effects of Natural Gas Composition on the Operation of an HCCI Engine O

    A Comprehensive Numerical Study on Effects of Natural Gas Composition on the Operation of an HCCI Engine O. Jahanian, S. A. Jazayeri To cite this version: O. Jahanian, S. A. Jazayeri. A Comprehensive Numerical Study on Effects of Natural Gas Com- position on the Operation of an HCCI Engine. Oil & Gas Science and Technology - Revue d’IFP Energies nouvelles, Institut Français du Pétrole, 2012, 67 (3), pp.503-515. 10.2516/ogst/2011133. hal-01936489 HAL Id: hal-01936489 https://hal.archives-ouvertes.fr/hal-01936489 Submitted on 27 Nov 2018 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. ogst100033_Jahanian 6/06/12 16:01 Page 503 Oil & Gas Science and Technology – Rev. IFP Energies nouvelles, Vol. 67 (2012), No. 3, pp. 503-515 Copyright © 2011, IFP Energies nouvelles DOI: 10.2516/ogst/2011133 A Comprehensive Numerical Study on Effects of Natural Gas Composition on the Operation of an HCCI Engine O. Jahanian* and S.A. Jazayeri Department of Mechanical Engineering, K. N. Toosi University of Technology, P.O. Box 19395-1999, Tehran - Iran e-mail: [email protected] - [email protected] * Corresponding author Résumé — Une étude numérique complète sur les effets de la composition du gaz naturel carburant sur le réglage d'un moteur HCCI — Le moteur HCCI (Homogeneous Charge Compression Ignition, ou à allumage par compression d'une charge homogène) est une idée prometteuse pour réduire la consommation de carburant et les émissions polluantes.