1、Designation: D 2779 92 (Reapproved 2007)An American National StandardStandard Test Method forEstimation of Solubility of Gases in Petroleum Liquids1This standard is issued under the fixed designation D 2779; the number immediately following the designation indicates the year oforiginal adoption or,
2、in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the estimation of the equilib-rium solubility of several
3、 common gases encountered in theaerospace industry in hydrocarbon liquids. These includepetroleum fractions with densities in the range from 0.63 to0.90 at 288 K (59F). The solubilities can be estimated over thetemperature range 228 K (50F) to 423 K (302F).1.2 This test method is based on the Clausi
4、us-Clapeyronequation, Henrys law, and the perfect gas law, with empiri-cally assigned constants for the variation with density and foreach gas.1.3 The values stated in SI units are to be regarded as thestandard. The values in parentheses are for information only.1.4 This standard does not purport to
5、 address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1298 Te
6、st Method for Density, Relative Density (SpecificGravity), or API Gravity of Crude Petroleum and LiquidPetroleum Products by Hydrometer Method3. Terminology3.1 Definitions:3.1.1 Ostwald coeffcientthe solubility of a gas expressedas the volume of gas dissolved per volume of liquid when thegas and liq
7、uid are in equilibrium at the specified partialpressure of gas and at the specified temperature.3.1.2 Bunsen coeffcientthe solubility of a gas expressedas the volume, reduced to 273 K (32F) and 101.3 kPa (1 atm),dissolved by 1 volume of liquid at the specified temperatureand 101.3 kPa.3.1.3 Henrys l
8、awthe principle that the ratio of partialpressure to mole fraction of gas in solution is a constant.3.1.3.1 DiscussionIn non-ideal systems the fugacity isused to replace the pressure, but the systems within the scopeof this test method can be considered ideal within the limits ofthe accuracy stateme
9、nt.3.2 Symbols:d = density of the liquid at 288 K (59F), kg/L,T = specified temperature, K,Lo= Ostwald coefficient at 273 K for a liquid ofd = 0.85,L = Ostwald coefficient at T for a liquid ofd = 0.85,Lc= Ostwald coefficient at T for a liquid of thespecified density,p = pressure of the gas, or mixed
10、 gases, MPa,pv= vapor pressure of the liquid at the specifiedtemperature, MPa,p1,p2. pi= partial pressures of the gases in a mixture,MPa,G = solubility, mg/kg,B = Bunsen coefficient at the specified d, p, and T,X = mole fraction of gas in equilibrium solution,Lm,Bm= coefficients for mixture of gases
11、,M = molecular weight of the gas, g/mol,Ml= molecular weight of the liquid, g/mol,H = Henrys law constant, MPa, andC = molarity, kg mol/m3.4. Summary of Test Method4.1 Correlations have been established by the NationalAeronautics and Space Administration (formerly NationalAdvisory Committee onAerona
12、utics) in NACATechnical Note3276 (1956)3Their work was extended to include most of thedata published since that time, and extrapolated by semi-empirical methods into regions where no data are available.4.2 The only data required are the density of liquid at 288 K(59F) and the nature of the gas. Thes
13、e are used in theequations, with the specific constant for the gas from Table 1,or with Fig. 1, to estimate the Ostwald coefficient.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.11 on Engineer
14、ing Sciences of High Performance Fluids and Solids.Current edition approved May 1, 2007. Published June 2007. Originallyapproved in 1969. Last previous edition approved in 2002 as D 2779 92 (2002).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service a
15、t serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from National Aeronautics and Space Administration, Washington,DC.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, P
16、A 19428-2959, United States.5. Significance and Use5.1 Knowledge of gas solubility is of extreme importance inthe lubrication of gas compressors. It is believed to be asubstantial factor in boundary lubrication, where the suddenrelease of dissolved gas may cause cavitation erosion, or evencollapse o
17、f the fluid film. In hydraulic and seal oils, gasdissolved at high pressure can cause excessive foaming onrelease of the pressure. In aviation oils and fuels, the differencein pressure between take-off and cruise altitude can causefoaming out of the storage vessels and interrupt flow to thepumps.6.
18、Procedure6.1 Determine d by Test Method D 1298 if it is nototherwise available.6.2 Determine L for the desired gas at T from Fig. 1,ifitisshown.6.3 Determine Lofrom Table 1 for gases not shown in Fig.1.6.4 Calculate L for such gases by the equationL 5 0.300 exp 0.639700 T!/T!ln 3.333Lo# (1)6.4.1 (Eq
19、 1) is based on the assumption that all gases haveL = 0.3 at 700 K (800F). All the constants are empirical. Theequation shall not be applied to such gases as methane orethylene. When there is a difference, the result from Fig. 1 is tobe preferred over that from Table 1.6.5 The Ostwald coefficient L
20、applies only to liquids ofd = 0.85. To correct to other densities, use the followingequation:Lc5 7.70L0.980 d! (2)NOTE 1The constant 0.980 is based on the intermolecular volume ofhydrocarbons as measured by compressibility and contraction on freezing.It is also the best empirical fit of the data. Th
21、e use of this equation for verydense liquids is inadvisable, as the Ostwald coefficient becomes negativeabove d = 0.980. The constant 7.70 is also predictable from moleculartheory, but the value used was determined empirically.6.6 Calculate the Bunsen coefficient using the followingequation:B 5 2697
22、p pv!L/T (3)NOTE 2Fig. 2 shows the relations of the various solubility expressionsto one another in chart form.6.7 Calculate the solubility, which is expressed sometimesas parts per million by weight, using the following equation:G 5SBMg0.0224D HdF1 2 0.000595ST 2 288.6d1.21 DGJ21(4)where:0.0224 = m
23、olar volume at 273 K and 101.3 kPa in litres permole, and 0.000595 and 1.21 = empirical con-stants for correcting d to specified T.6.8 Calculate the solubility as the mol fraction by using thefollowing equation:X 5 106G 3 Mt/Mgneglecting the moles of gas in the divisor! (5)6.9 Calculate the Henrys l
24、aw constant as follows:H 5 p pv!/X (6)6.10 Calculate the solubility coefficient for a mixture ofgases as follows:6.10.1 Calculate the individual Ostwald coefficients as de-scribed in 6.2 or 6.4, and combine them using the followingequation:Lm5 Lc13 p11 Lc23 p2.Lci3 pi!/p (7)6.10.2 Calculate the Buns
25、en coefficient using the followingequation:Bm5 273pLm/T (8)7. Precision and Bias47.1 PrecisionThe repeatability of prediction for variousgases is shown in Table 2, expressed as the 95 % confidenceinterval. Only in one case out of 20 will the percent differencebetween the predicted value and an accep
26、ted experimentalvalue exceed that shown, within the temperature range indi-cated in Table 1.7.2 BiasThe Lovalues were selected to give a bias of lessthan 2 % for each gas.8. Keywords8.1 gases; petroleum liquids; solubility4Supporting data have been filed at ASTM International Headquarters and maybe
27、obtained by requesting Research Report RR:D02-1129.TABLE 1 Ostwald Coefficients at 0C for Petroleum Liquids withd = 0.85GasOstwaldCoefficient, LoValidatedATemperatureRange, CHelium 0.012 20150Neon 0.018 1540Hydrogen 0.040 0200Nitrogen 0.069 0200Air 0.098 0100Carbon monoxide 0.12 25200Oxygen 0.16 251
28、00Argon 0.18 1540Methane use Fig. 1B0150Krypton 0.60 1540Carbon dioxide 1.45B25215Ammonia 1.7B25200Xenon 3.3 1540Ethylene use Fig. 1B22200Hydrogen sulfide 5.0B25200AIndicated by solid lines in Fig. 1.BDo not use this method for these gases in highly aromatic liquids.D 2779 92 (2007)2FIG. 1 Solubilit
29、y of Gases in Petroleum Liquids with d = 0.85D 2779 92 (2007)3FIG. 2 Solubility Conversion ChartD 2779 92 (2007)4ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advi
30、sed that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either
31、reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If
32、 you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individ
33、ual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).TABLE 2 Precision and Bias of Predictions of Gas SolubilityGas Data Points95 % ConfidenceInterval, %He 24 48Ne 16 46H226 70N277 76Air 99 28CO 12 82O249 44Ar 15 47CH440 44Kr 15 49CO272 95NH319 55Xe 7 123C2H424 25H2S30 75D 2779 92 (2007)5
