1、Designation: E 2071 00 (Reapproved 2005)Standard Practice forCalculating Heat of Vaporization or Sublimation from VaporPressure Data1This standard is issued under the fixed designation E 2071; the number immediately following the designation indicates the year oforiginal adoption or, in the case of
2、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 practice describes the calculation of the heat ofvaporization of a liquid or the heat of s
3、ublimation 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
4、to 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 fromthi
5、s practice 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 SI values are standard.1.3 This standard does not purport to address all of thesafety concerns, if any,
6、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.1.4 There is no ISO standard equivalent to this practice.2. Referenced Documents2.1 ASTM Standar
7、ds:2D 2879 Standard Test Method for Vapor Pressure-Temperature Relationship and Initial Decomposition Tem-perature of Liquids by IsoteniscopeE 1142 Standard Terminology Relating to ThermophysicalPropertiesE 1194 Standard Test Method for Vapor PressureE 1719 Standard Test Method for Vapor Pressure of
8、 Liquidsby EbulliometryE 1782 Standard Test Method for Determining Vapor Pres-sure by Thermal 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 Pvapor pressure, kPa.3.1.3 Pccritical pres
9、sure, 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 vaporization, J/mol.3.1.11 DZVdifference in compress
10、ibility 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,substitute the subscript “S” for the sublimat
11、ion of a solid.3.2 Definitions:3.2.1 Specialized terms used in this practice are defined inTerminology E 1142.3.2.2 sublimationtransition from a solid phase to a gas-eous phase.3.2.3 vaporizationtransition from a liquid phase to agaseous phase.4. Summary of Practice4.1 Vapor pressure data are measur
12、ed by other referencedASTM Standards and then correlated with the Antoine equa-tion. The heat of vaporization or sublimation is computed at thedesired temperature from the vapor-pressure temperature de-rivative from the fitted Antoine equation by use of theClapeyron equation (1)3. In the Clapeyron e
13、quation, DZVis1This practice is under the jurisdiction of Committee E37 on Thermal Measure-ments and is the direct responsibility of Subcommittee E37.01 on Test Methods andRecommended Practices.Current edition approved March 1, 2005. Published April 2005. Originallyapproved in 2000. Last previous ed
14、ition approved in 2000 as E 207100.2For referenced ASTM standards, visit the ASTM website, 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.3The boldface numbers give
15、n in parentheses refer to a list of references at theend of the text.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.determined by either the Clausius-Clapeyron (2) approxima-tion DZV5 1! or the Haggenmacher(3) approximationDZV5 $1Pr
16、/Tr!3#%1/2! .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 t
17、hermodynamic 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 a
18、pplications.6. Experimental Vapor Pressure Data6.1 Vapor pressure data are measured by Test MethodsD 2879, E 1194, E 1719,orE 1782. Note the safety precau-tions contained in the test method used.6.1.1 Vapor pressure data from other reliable sources, forexample, peer-review technical journals, may be
19、 used. Thesource 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 MethodE 1719 for details on least-squares regression of vapor pressuredata.7. Calculation7.1 At each temperature of interest, calculate the
20、 vaporpressure from 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.
21、2.2 The Haggenmacher 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 thecond
22、ensed and gaseous 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 t
23、he vapor pressure 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
24、critical temperature 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 su
25、blimation.8.1.6 The specific dated version of E 2071 used8.2 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; vaporpr
26、essureANNEX(Mandatory Information)A1. SAMPLE CALCULATIONS AND REPORTA1.1 Source of Sample Vapor Pressure Data:A1.1.1 This sample calculation is performed on the samplevapor pressure data given for a toluene specimen in Annex A3of Test Method E 1719. Heat of vaporization is calculated in 10K incremen
27、ts between 290 and 400 K. Calculations for boththe Clausius-Clapeyron and Haggenmacher approximations toDZVare listed.A1.2 Sample Experimental Data:A1.2.1 These controlled pressure-boiling temperature datapairs were measured by Test Method E 1719 ona75cm3specimen charged to a vapor-lift pump ebullio
28、meter:P (kPa) T(K)10.0 318.420.0 335.430.0 345.850.0 360.770.0 371.285.0 377.9100.0 383.3A1.2.2 A non-linear least-squares fit of the Antoine equa-tion, log10P=A-B/(T + C), produced these constants:A (fit) = 6.168057B (fit) = 1397.23C (fit) = 48.10A1.3 Sample Calculation:E 2071 00 (2005)2A1.3.1 The
29、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 1397.23*2902/290 2 48.10!2#524623.8938 KA1.3.2 Haggenmacher approximation to DZV:DZV5 $10.
30、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! 5 38346.4 J/molA1.4 Sample Heat of Vaporization ReportA1.4.1 Clausius-Clapeyron Approxim
31、ation Report:A1.4.1.1 Data are for a toluene specimen and are listed inAnnex A3 of Test Method E 1719. These controlled pressure-boiling temperature data pairs were measured by Test MethodE 1719 ona75cm3specimen charged to a vapor-lift pumpebulliometer:P (kPa) T(K)10.0 318.420.0 335.430.0 345.850.0
32、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 Clausius Clapeyron approximation for DZVwas used.Temperature Pressure d(lnP)/d(1/T) DZ
33、VDHVK kPa K J/mol290 2.4659968 4623.8938 1.00000000 38444.6300 4.1811179 4563.2028 1.00000000 37940.0Temperature Pressure d(lnP)/d(1/T) DZVDHVK kPa K J/mol310 6.8089762 4507.5026 1.00000000 37476.9320 10.697757 4456.2047 1.00000000 37050.4330 16.277326 4408.8094 1.00000000 36656.3340 24.064868 4364.
34、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 34561.5A1.4.2 Haggenmacher Appro
35、ximation Report:A1.4.2.1 Data are for a toluene specimen and are listed inAnnex A3 of Test Method E 1719. These controlled pressure-boiling temperature data pairs were measured by Test MethodE 1719 ona75cm3specimen charged to a vapor-lift pumpebulliometer:P (kPa) T(K)10.0 318.420.0 335.430.0 345.850
36、.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 critical temperature and pressure us
37、ed 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 36744.1330 16.277326 4408.8094 0.988
38、51253 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 157.58889 4156.8566 0.93585171
39、32344.4E 2071 00 (2005)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-Hill, New York, NY, 1982, p. 10
40、0.(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, DesignInstitute of Physical Prope
41、rty 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 validity of any such patent rights
42、, 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 reapproved or withdrawn. Your comments are invited either for re
43、vision 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 you feel that your comments have not received a fair hearing yo
44、u 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. Individual 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).E 2071 00 (2005)4
