Speed of Sound Measurements and a Fundamental Equation of State for Cyclopentane

The speed of sound in liquid cyclopentane has been measured in the temperature range from (258 to 353) K at pressures up to 30 MPa (42 data points) using a pulse-echo method with a double path type sensor. The expanded overall uncertainty (k = 2) in the speed of sound measurements is estimated to be 0.2 %. A function for the speed of sound with inputs of temperature and pressure has been fitted to the experimental results. The new speed of sound data along with available literature data were used to develop a fundamental Helmholtz equation of state for cyclopentane. Typical expanded uncertainties of properties calculated using the new equations are 0.2 % in density in the liquid phase, 1 % in heat capacity, 0.2 % in liquid-phase sound speed, and 0.5 % in vapor pressure. The equation of state is valid from the triple-point temperature, 179.7 K, to temperatures of 550 K with pressures to 250 MPa.

[1]  G. S. Parks,et al.  Thermal Data on Organic Compounds. XIV. Some Heat Capacity, Entropy and Free Energy Data for Cyclic Substances , 1934 .

[2]  I. Gascón,et al.  Speeds of Sound and Isentropic Compressibilities for Binary Mixtures of a Cyclic Diether with a Cyclic Compound at Three Temperatures , 2006 .

[3]  H. Preston‐Thomas,et al.  The International Temperature Scale of 1990 (ITS-90) , 1990 .

[4]  K. Marsh.  Enthalpies of mixing and excess Gibbs free energies of mixtures of octamethylcyclotetrasiloxane+cyclopentane at 291.15, 298.15, and 308.15 K , 1970 .

[5]  W. Kay.  Vapor Pressures and Saturated Liquid and Vapor Densities of Cyclopentane, Methylcyclopentane, Ethylcyclopentane and Methylcyclohexane , 1947 .

[6]  Stephan Kabelac,et al.  Speed of sound instrument for fluids with pressures up to 100 MPa , 2006 .

[7]  T. Takagi,et al.  Speed of sound in liquid cyclic alkanes at temperatures between (283 and 343) K and pressures up to 20 MPa , 2002 .

[8]  T. Boublı́k,et al.  Vapour-liquid equilibrium and excess molar volume of (trans-1,2-dichloroethene + cyclopentane) at 293.15 K , 1985 .

[9]  E. Kuss,et al.  p, V, T‐Messungen an zwanzig organischen Flüssigkeiten , 1970 .

[10]  Frederick D. Rossini,et al.  Vapor pressures and boiling points of some paraffin, alkylcyclopentane, alkylcyclohexane, and alkylbenzene hydrocarbons , 1945 .

[11]  J. Schouten,et al.  Determination of the thermodynamic properties of liquid ethanol from 193 to 263 K and up to 280 MPa from speed-of-sound measurements , 1991 .

[12]  D. Ambrose,et al.  The critical temperatures of some hydrocarbons and pyridine bases , 1957 .

[13]  I. Mokbel,et al.  Vapor pressures of 12 alkylcyclohexanes, cyclopentane, butylcyclopentane and trans-decahydronaphthalene down to 0.5 Pa. Experimental results, correlation and prediction by an equation of state , 1995 .

[14]  D. R. Douslin,et al.  The Heat Capacities, Heats of Transition, Heats of Fusion and Entropies of Cyclopentane, Methylcyclopentane and Methylcyclohexane1 , 1946 .

[15]  R. Span,et al.  An apparatus for the determination of speeds of sound in fluids , 2010 .

[16]  J. Tojo,et al.  Density, viscosity, and speed of sound of dialkyl carbonates with cyclopentane and methyl cyclohexane at several temperatures , 2004 .

[17]  M. McLinden,et al.  NIST Standard Reference Database 23: Reference Fluid Thermodynamic and Transport Properties-REFPROP, Version 9.1 | NIST , 2013 .

[18]  J. Mccullough,et al.  Thermodynamics of cyclopentane, methylcyclopentane and 1,cis-3-dimethylcyclopentane: verification of the concept of pseudorotation , 1959 .

[19]  G. Freeman,et al.  The effects of pressure on the density, dielectric constant, and viscosity of several hydrocarbons and other organic liquids , 1969 .

[20]  K. R. Harris,et al.  Temperature and Density Dependence of the Viscosity of Cyclopentane , 2004 .

[21]  Eric W. Lemmon,et al.  Thermodynamic Properties of Propane. III. A Reference Equation of State for Temperatures from the Melting Line to 650 K and Pressures up to 1000 MPa , 2009 .

[22]  E. L. Pace,et al.  Thermal Properties of Cyclopentane and Its Use as a Standard Substance in Low Temperature Thermal Measurements , 1947 .

[23]  V. Baonza,et al.  Study of the equation of state of liquid 2,3-dimethylbutane at high pressures , 1993 .