ASTM_D_4651_-_14_2020.pdf

Designation:D465114(Reapproved 2020)Standard Specification forIsobutane Thermophysical Property Tables1This standard is issued under the fixed designation D4651;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,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 The thermophysical property tables for isobutane are foruse in the calculation of the pressure-volume-temperature(PVT),thermodynamic,and transport properties of isobutanefor process design and operations.Two tables provide proper-ties at the conditions of liquid-vapor equilibrium(saturationproperties),one for liquid and one for vapor,at temperaturesbetween 120 K and the critical point,407.81 K.A third tableprovides properties at selected T,p points for the equilibriumphase at temperatures between 120 K and 570 K at pressures to20 MPa.The tables were developed using the National Instituteof Standards and Technology Standard Reference Databaseproduct REFPROP,version 9.1.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Applicability2.1 These tables apply directly only to pure isobutane.Theymay also be used in mathematical models and tables for thethermophysical properties of mixtures containing isobutane.3.Tables3.1 These tables were produced by equations from a com-puter package,“NIST Standard Reference Database 23;Ref-erence Fluid Thermodynamic and Transport Properties Data-base(REFPROP):Version 9.1.”2A wide selection of units(SIunits,engineering units,chemical units)and additional prop-erties are available with this program.3.2 These thermophysical property tables are:3.2.1 Thermophysical Properties of Isobutane Liquid atVapor-Liquid Equilibrium,in SI units.See Table 1.3.2.2 Thermophysical Properties of Isobutane Vapor atVapor-Liquid Equilibrium,in SI units.See Table 2.3.2.3 Thermophysical Properties of Isobutane AlongIsobars,in SI units.See Table 3.3.3 The symbols are:T,temperature(K),molar density(molL-1)H,molar enthalpy(Jmol-1)S,molar entropy(JK-1mol-1)Cv,constant volume molar heat capacity(JK-1mol-1)Cp,constant pressure molar heat capacity(JK-1mol-1)c,speed of sound(ms-1),viscosity(Pas),thermal conductivity(mWm-1K-1)3.4 The tabulated thermophysical properties are:,molar density(molL-1)H,molar enthalpy(Jmol-1)S,molar entropy(JK-1mol-1)Cv,constant volume molar heat capacity(JK-1mol-1)Cp,constant pressure molar heat capacity(JK-1mol-1)c,speed of sound(ms-1),viscosity(Pas),thermal conductivity(mWm-1K-1)4.Additional Information4.1 Reference state properties are required to calculate thethermodynamic properties enthalpy and entropy from an equa-tion of state formulation.The reference state properties usedare those specified by the International Institute of Refrigera-tion(IIR):enthalpy,H=200 J/g,and entropy,S=1 J/(gK),forthe saturated liquid at 273.15K(0 C).4.2 The molar mass of isobutane is 58.122 g/mol.1This specification is under the jurisdiction of ASTM Committee D03 onGaseous Fuels and is the direct responsibility of Subcommittee D03.08 onThermophysical Properties.Current edition approved April 1,2020.Published May 2020.Originallyapproved in 1987.Last previous edition approved in 2014 as D4651 14.DOI:10.1520/D4651-14R20.2Available from Standard Reference Data,National Institute of Standards andTechnology(NIST),100 Bureau Drive,Stop 3460,Gaithersburg,MD 20899.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.TABLE 1 Thermophysical Properties of Isobutane Liquid at Vapor-Liquid EquilibriumTPHSCvCpcKMPamoll-1Jmol-1Jmol-1K-1Jmol-1K-1Jmol-1K-1ms-1PasmWm-1K-11201.0633E-0712.636-5912.6-34.21669.00199.3081945.46055.8156.731221.6734E-0712.603-5713.6-32.57169.25199.6811928.55441.0156.301242.5915E-0712.571-5513.9-30.94869.501100.061911.94910.8155.851263.9524E-0712.538-5313.4-29.34469.752100.431895.54450.9155.381285.