1、Designation: E2071 00 (Reapproved 2010)Standard Practice forCalculating Heat of Vaporization or Sublimation from VaporPressure Data1This standard is issued under the fixed designation E2071; the number immediately following the designation indicates the year oforiginal adoption or, in the case of re
2、vision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice describes the calculation of the heat ofvaporization of a liquid or the heat of subl
3、imation of a solidfrom measured vapor pressure data. It is applicable to pureliquids, azeotropes, pure solids, and homogenous solid solu-tions over the temperature range for which the vapor pressureequation fitted to the measured data is applicable.NOTE 1This practice is generally not applicable to
4、liquid mixtures.For a pure liquid or azeotrope, composition does not change uponvaporization so that the integral heat of vaporization is identical to thedifferential heat of vaporization. Non-azeotropic liquid mixtures changecomposition upon vaporizing. Heat of vaporization data computed fromthis p
5、ractice for a liquid mixture are valid only as an approximation to themixture differential heat of vaporization; it is not a valid approximation tothe mixture integral heat of vaporization.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in
6、thisstandard.1.3 There is no ISO standard equivalent to this practice.1.4 This standard does not purport to 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
7、 applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D2879 Test Method for Vapor Pressure-Temperature Rela-tionship and Initial Decomposition Temperature of Liquidsby IsoteniscopeE1142 Terminology Relating to Thermophysical PropertiesE1194 Test Method for
8、 Vapor PressureE1719 Test Method for Vapor Pressure of Liquids byEbulliometryE1782 Test Method for Determining Vapor Pressure byThermal Analysis3. Terminology3.1 Symbols:3.1.1 A, B, CAntoine vapor pressure equation constants(log10, kPa, K), Antoine vapor pressure equation:log10P 5 A 2 B/T 1 C!3.1.2
9、Pvapor pressure, kPa.3.1.3 Pccritical pressure, kPa.3.1.4 Prreduced pressure = P/Pc.3.1.5 Tabsolute temperature, K.3.1.6 Tccritical temperature, K.3.1.7 Trreduced temperature = T/Tc.3.1.8 Vmolar volume, cm3/mol.3.1.9 Rgas constant, 8.31433 J/mol-K; 8314330 kPa-cm3/mol-K.3.1.10 DHVheat of vaporizatio
10、n, J/mol.3.1.11 DZVdifference in compressibility factor (Z = PV/RT) upon vaporization. Clapeyron equation:DHV52RDZVdlnP!/d1/T!#3.1.11.1 DiscussionThe subscript “V” will be usedthroughout this practice to designate the vaporization of aliquid. If the vapor pressure data were measured for a solid,subs
11、titute the subscript “S” for the sublimation of a solid.3.2 Definitions:3.2.1 Specialized terms used in this practice are defined inTerminology E1142.3.2.2 sublimationtransition from a solid phase to a gas-eous phase.3.2.3 vaporizationtransition from a liquid phase to agaseous phase.4. Summary of Pr
12、actice4.1 Vapor pressure data are measured by other referencedASTM Standards and then correlated with the Antoine equa-tion. The heat of vaporization or sublimation is computed at the1This practice is under the jurisdiction of Committee E37 on Thermal Measure-ments and is the direct responsibility o
13、f Subcommittee E37.10 on Fundamental,Statistical and Mechanical Properties.Current edition approved July 1, 2010. Published August 2010. Originallyapproved in 2000. Last previous edition approved in 2000 as E2071 00 (2005).DOI: 510.1520/E2071-00R10.2For referenced ASTM standards, visit the ASTM webs
14、ite, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United Stat
15、es.desired temperature from the vapor-pressure temperature de-rivative from the fitted Antoine equation by use of theClapeyron equation (1).3In the Clapeyron equation, DZVisdetermined by either the Clausius-Clapeyron (2) approxima-tion DZV5 1! or the Haggenmacher (3) approximationDZV5 $1Pr/Tr!3#%1/2
16、! .4.2 An example calculation is given in Annex A1.5. Significance and Use5.1 If the heat of vaporization or sublimation is absorbed orliberated in a process at constant pressure, it is called enthalpyof vaporization or sublimation. Enthalpy of vaporization orsublimation is a fundamental thermodynam
17、ic property of aliquid or solid. It is an important quantity in the design of heatexchangers and other chemical process units. Enthalpy ofvaporization is also used to calculate solubility parameters (4).5.2 This practice may be used in research, regulatorycompliance, and quality assurance applicatio
18、ns.6. Experimental Vapor Pressure Data6.1 Vapor pressure data are measured by Test MethodsD2879, E1194, E1719,orE1782. Note the safety precautionscontained in the test method used.6.1.1 Vapor pressure data from other reliable sources, forexample, peer-review technical journals, may be used. Thesourc
19、e of the vapor pressure data must be noted.6.2 The measured vapor pressure data are fitted to anAntoine vapor pressure equation. See 10.3 in Test MethodE1719 for details on least-squares regression of vapor pressuredata.7. Calculation7.1 At each temperature of interest, calculate the vaporpressure f
20、rom the Antoine equation and calculate the vapor-pressure temperature derivative from the fitted Antoine equa-tion constants from:dlnP!/d1/T!# 522.3025851BT2/T 1 C!2#7.2 Calculate an approximation to DZVat each temperature.7.2.1 The Clausius-Clapeyron approximation to DZVis:DZV 1.07.2.2 The Haggenma
21、cher approximation to DZVis:DZV5 $1Pr/Tr!3#%12NOTE 2The Clausius-Clapyeron approximation is generally used forsolids and for liquids at low Tr. The Haggenmacher approximation isgenerally used for liquids up to Tr 0.75.7.2.3 If equation of state (Z) data are available for both thecondensed and gaseou
22、s phases, DZVmay be calculated directlyfrom the equation of state data.7.3 Calculate the heat of vaporization or heat of sublimationat each temperature from the Clapeyron equation:DHV52RDZVdlnP!/d1/T!#8. Report8.1 Report the following information:8.1.1 The test method and source of the vapor pressur
23、e dataused in the heat of vaporization or heat of sublimationcalculation. A vapor pressure data table shall also be reported.8.1.2 The Antoine equation constants fitted to the vaporpressure data.8.1.3 The approximation to DZVused in the calculation.8.1.4 The values and source of the critical tempera
24、ture andcritical pressure data if the Haggenmacher approximation wasused for DZ.8.1.5 A table that contains temperature, vapor pressure, thevapor pressure temperature derivative d (lnP)/d (1/T), differ-ence in compressibility factor (DZV), and DHV, the heat ofvaporization or heat of sublimation.8.1.
25、6 The specific dated version of this practice used.8.2 See the sample calculations and report in Annex A1.9. Keywords9.1 Antoine equation; Clausius-Clapeyron equation; en-thalpy of sublimation; enthalpy of vaporization; Haggenma-cher equation; heat of sublimation; heat of vaporization; vaporpressure
26、ANNEX(Mandatory Information)A1. SAMPLE CALCULATIONS AND REPORTA1.1 Source of Sample Vapor Pressure DataA1.1.1 This sample calculation is performed on the samplevapor pressure data given for a toluene specimen in Annex A3of Test Method E1719. Heat of vaporization is calculated in10 K increments betwe
27、en 290 and 400 K. Calculations for boththe Clausius-Clapeyron and Haggenmacher approximations toDZVare listed.A1.2 Sample Experimental DataA1.2.1 These controlled pressure-boiling temperature datapairs were measured by Test Method E1719 ona75cm3specimen charged to a vapor-lift pump ebulliometer:3The
28、 boldface numbers given in parentheses refer to a list of references at theend of the text.E2071 00 (2010)2P (kPa) T (K)10.0 318.420.0 335.430.0 345.850.0 360.770.0 371.285.0 377.9100.0 383.3A1.2.2 A non-linear least-squares fit of the Antoine equa-tion, log10P = A - B/(T + C), produced these consta
29、nts:A (fit) = 6.168057B (fit) = 1397.23C (fit) = 48.10A1.3 Sample CalculationA1.3.1 The critical temperature and pressure for toluene (5)are:Tc= 591.75 KPc= 4108.69 kPaAt 290 K:Tr= 0.490071821Pr= 0.000600191Vapor pressure 5 10 6.168057 2 1397.23/290 2 48.10!#5 2.465997 kPadlnP!/d1/T!# 522.3025851 13
30、97.23*2902/290 2 48.10!2#524623.8938 KA1.3.2 Haggenmacher approximation to DZV:DZV5 $10.000600191/0.4900718121!3#%12 5 0.997447A1.3.3 DHVfrom Clausius-Clapeyron approximation:DHV5 28.31433!*1.00*24623.8938! 5 38444.6 J/molA1.3.4 DHVfrom Haggenmacher approximation:DHV5 28.31433!*0.997447*24623.8938!
31、5 38346.4 J/molA1.4 Sample Heat of Vaporization ReportA1.4.1 Clausius-Clapeyron Approximation Report:A1.4.1.1 Data are for a toluene specimen and are listed inAnnex A3 of Test Method E1719. These controlled pressure-boiling temperature data pairs were measured by Test MethodE1719 ona75cm3specimen ch
32、arged to a vapor-lift pumpebulliometer:P (kPa) T (K)10.0 318.420.0 335.430.0 345.850.0 360.770.0 371.285.0 377.9100.0 383.3A1.4.1.2 A non-linear least-squares fit of the Antoine equa-tion, log10P 5 A 2 B/T 1 C! , produced these constants:A (fit) = 6.168057B (fit) = 1397.23C (fit) = 48.10A1.4.1.3 The
33、 Clausius Clapeyron approximation for DZVwas used.Temperature Pressure d(lnP)/d(1/T) DZVDHVK kPa K J/mol290 2.4659968 4623.8938 1.00000000 38444.6300 4.1811179 4563.2028 1.00000000 37940.0310 6.8089762 4507.5026 1.00000000 37476.9320 10.697757 4456.2047 1.00000000 37050.4330 16.277326 4408.8094 1.00
34、000000 36656.3340 24.064868 4364.8893 1.00000000 36291.1350 34.668504 4324.0774 1.00000000 35951.8360 48.788774 4286.0560 1.00000000 35635.7370 67.217970 4250.5496 1.00000000 35340.5380 90.837442 4217.3173 1.00000000 35064.2390 120.61303 4186.1482 1.00000000 34805.0400 157.58889 4156.8566 1.00000000
35、 34561.5A1.4.2 Haggenmacher Approximation Report:A1.4.2.1 Data are for a toluene specimen and are listed inAnnex A3 of Test Method E1719. These controlled pressure-boiling temperature data pairs were measured by Test MethodE1719 ona75cm3specimen charged to a vapor-lift pumpebulliometer:P (kPa) T (K)
36、10.0 318.420.0 335.430.0 345.850.0 360.770.0 371.285.0 377.9100.0 383.3A1.4.2.2 A non-linear least-squares fit of the Antoine equa-tion, log10P 5 A 2 B/T 1 C! , produced these constants:A (fit) = 6.168057B (fit) = 1397.23C (fit) = 48.10A1.4.2.3 The Haggenmacher approximation for DZVwasused. The crit
37、ical temperature and pressure used for toluene (5)are:Tc= 591.75 KPc= 4108.69 kPaTemperature Pressure d(lnP)/d(1/T) DZVDHVK kPa K J/mol290 2.4659968 4623.8938 0.99744709 38346.4300 4.1811179 4563.2028 0.99608744 37791.5310 6.8089762 4507.5026 0.99421990 37260.2320 10.697757 4456.2047 0.99173347 3674
38、4.1330 16.277326 4408.8094 0.98851253 36235.2340 24.064868 4364.8893 0.98443961 35726.4350 34.668504 4324.0774 0.97939800 35211.1360 48.788774 4286.0560 0.97327384 34683.3370 67.217970 4250.5496 0.96595780 34137.4380 90.837442 4217.3173 0.95734617 33568.5390 120.61303 4186.1482 0.94734133 32972.2400
39、 157.58889 4156.8566 0.93585171 32344.4E2071 00 (2010)3REFERENCES(1) Van Ness, H. C., and Abbott, M. M., Classical Thermodynamics ofNonelectrolyte Solutions, McGraw-Hill, New York, NY, 1982, pp.96100.(2) Van Ness, H. C., and Abbott, M. M., Classical Thermodynamics ofNonelectrolyte Solutions, McGraw-
40、Hill, New York, NY, 1982, p. 100.(3) Haggenmacher, J. E., Journal of the American Chemical Society,Vol68, 1946.(4) Barton, A. F. M., CRC Handbook of Solubility Parameters and OtherCohesion Parameters, CRC Press, Boca Raton, FL, 1991.(5) Daubert, T. E., ed., The DIPPR Project 801 Data Compilation,Des
41、ign Institute of Physical Property Data, AICHE, New York, NY,1990, CAS#, 108883.ASTM 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 advised that determination of the val
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45、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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).E2071 00 (2010)4
