p-Xylene !Short name 106-42-3 !CAS number 1,4-Dimethylbenzene !Full name C8H10 !Chemical formula {C8H10} p-Xylene !Synonym 106.165 !Molar mass [g/mol] 286.4 !Triple point temperature [K] 411.470 !Normal boiling point [K] 616.168 !Critical temperature [K] 3531.5 !Critical pressure [kPa] 2.69392 !Critical density [mol/L] 0.324 !Acentric factor 0.0 !Dipole moment [Debye]; (exactly zero due to symmetry) van Arkel, A.E., P. Meerburg, and C.R. van der Handel, Rec. Trav. Chim., 61, 767-770 (1942). NBP !Default reference state 10.0 !Version number 1307 !UN Number :UN: aromatic !Family :Family: 4593.938 !Heating value (upper) [kJ/mol] :Heat: 1S/C8H10/c1-7-3-5-8(2)6-4-7/h3-6H,1-2H3 !Standard InChI String :InChi: URLKBWYHVLBVBO-UHFFFAOYSA-N !Standard InChI Key :InChiKey: f174a9b0 (octane) !Alternative fluid for mixing rules :AltID: 01b0e650 !Hash number from InChI Key :Hash: !The fluid files contain general information about the fluid in the first 15 to 20 lines, followed by sections for the ! equations of state, transport equations, and auxiliary equations. Equations of state are listed first. The NIST recommended ! equations begin with a hash mark (#). The secondary equations begin with the @ symbol. These symbols can be swapped to ! select a secondary equation as primary and the primary as secondary. The equation of state section also contains auxiliary ! equations for the ideal gas heat capacity or ideal gas Helmholtz energy. Below the equations of state (both primary and ! secondary) are the transport equations, first viscosity and then thermal conductivity. These are then followed by the ! secondary equations if available. The transport section also contains auxiliary equations required to calculate either the ! dilute gas state or the critical enhancement. At the end of the file are additional but not necessary auxiliary equations, ! including simple equations for the vapor pressure, saturated liquid and vapor densities, melting line (for some fluids), and ! sublimation line (for even fewer fluids). This section also contains the equations for dielectric constant and surface ! tension if available. The sections are divided by different symbols (these being _-+=^*~) to aid the eye in locating a ! particular section. Secondary equations are indented 10 spaces to avoid confusion with the NIST recommended equations. The ! end of the fluid file is marked with @END. Anything below that is ignored. ! compiled by E.W. Lemmon, NIST Physical and Chemical Properties Division, Boulder, Colorado ! 03-12-09 EWL, Original version. ! 04-01-13 SH, Add ancillary equations. ! 04-06-13 EWL, Add dipole moment. ! 04-17-14 EWL, Add surface tension coefficients of Mulero et al. (2014). ! 06-17-14 MLH, Add preliminary transport. ! 12-08-14 MLH, Add thermal conductivity model of Mylona et al. (2014). ! 02-21-17 MLH, Add viscosity model of Balogun et al. (2015). ________________________________________________________________________________ #EOS !---Equation of state--- FEQ !Helmholtz equation of state for p-xylene of Zhou et al. (2012). :TRUECRITICALPOINT: 616.168 2.69392 !True EOS critical point [K, mol/L] (where dP/dD=0 and d^2P/dD^2=0 at constant T) :DOI: 10.1063/1.3703506 ? ?``````````````````````````````````````````````````````````````````````````````` ?Zhou, Y., Lemmon, E.W., and Wu, J., ? "Thermodynamic Properties of o-Xylene, m-Xylene, p-Xylene, and Ethylbenzene," ? J. Phys. Chem. Ref. Data, 41, 023103, 2012. ? ?The uncertainty in vapor pressure of the equation of state for p-xylene is ? 0.2% above 300 K. The uncertainties in saturated liquid density are 0.02% ? between 290 K and 350 K, and 0.2% elsewhere, due to a lack of reliable ? experimental data. The uncertainties in density are 0.2% in the liquid ? region and 1.0% elsewhere, including the critical and vapor regions. The ? uncertainty in sound speed is 0.3% in the liquid region, and the ? uncertainty in heat capacity is 1.0%. ? !``````````````````````````````````````````````````````````````````````````````` 286.4 !Lower temperature limit [K] 700.0 !Upper temperature limit [K] 200000.0 !Upper pressure limit [kPa] 8.166 !Maximum density [mol/L] CPP !Pointer to Cp0 model 106.165 !Molar mass [g/mol] 286.4 !Triple point temperature [K] 0.580 !Pressure at triple point [kPa] 8.165 !Density at triple point [mol/L] 411.470 !Normal boiling point temperature [K] 0.324 !Acentric factor 616.168 3531.5 2.69392 !Tc [K], pc [kPa], rhoc [mol/L] 616.168 2.69392 !Reducing parameters [K, mol/L] 8.314472 !Gas constant [J/mol-K] 12 4 4 12 0 0 0 0 0 0 0 0 !# terms and # coefs/term for normal terms, Gaussian terms, and Gao terms 0.0010786811 1.0 5. 0. !a(i),t(i),d(i),l(i) -0.103161822 0.83 1. 0. 0.0421544125 0.83 4. 0. 1.47865376 0.281 1. 0. -2.4266 0.932 1. 0. -0.46575193 1.1 2. 0. 0.190290995 0.443 3. 0. -1.06376565 2.62 1. 2. -0.209934069 2.5 3. 2. 1.25159879 1.2 2. 1. -0.951328356 3.0 2. 2. -0.0269980032 0.778 7. 1. 1.37103180 1.13 1. 2. 2. -1.179 -2.445 1.267 0.54944 0. 0. 0. -0.494160616 4.5 1. 2. 2. -1.065 -1.483 0.4242 0.7234 0. 0. 0. -0.0724317468 2.2 3. 2. 2. -1.764 -4.971 0.864 0.4926 0. 0. 0. -3.69464746 2.0 3. 2. 2. -13.675 -413.0 1.1465 0.8459 0. 0. 0. eta beta gamma epsilon EXP[eta*(delta-epsilon)^2+beta*(tau-gamma)^2] #AUX !---Auxiliary function for Cp0 CPP !Ideal gas heat capacity function for p-xylene of Zhou et al. (2012). ? ?``````````````````````````````````````````````````````````````````````````````` ?Zhou, Y., Lemmon, E.W., and Wu, J., 2012. ? !``````````````````````````````````````````````````````````````````````````````` 0. ! 10000. ! 0. ! 0. ! 1.0 8.314472 !Reducing parameters for T, Cp0 1 4 0 0 0 0 0 !Nterms: polynomial, exponential, cosh, sinh 5.2430504 0.0 5.2291378 414.0 19.549862 1256.0 16.656178 2649.0 5.9390291 6681.0 #AUX !---Auxiliary function for PX0 PX0 !Helmholtz energy ideal-gas function for p-xylene of Zhou et al. (2012). ? ?``````````````````````````````````````````````````````````````````````````````` ?Zhou, Y., Lemmon, E.W., and Wu, J., 2012. ? !``````````````````````````````````````````````````````````````````````````````` 1 2 4 0 0 0 0 0 !Nterms: ai*log(tau**ti); ai*tau**ti; ai*log(1-exp(bi*tau)) 4.2430504 1.0 !ai, ti for [ai*log(tau**ti)] terms 5.9815277224498971 0.0 !aj, ti for [ai*tau**ti] terms -0.5247807538556827 1.0 !aj, ti for [ai*tau**ti] terms 5.2291378 414.0 !aj, ti for [ai*log(1-exp(-ti/T)] terms 19.549862 1256.0 16.656178 2649.0 5.9390291 6681.0 #AUX !---Auxiliary function for PH0 PH0 !Ideal gas Helmholtz form for p-xylene of Zhou et al. (2012). ? ?``````````````````````````````````````````````````````````````````````````````` ?Zhou, Y., Lemmon, E.W., and Wu, J., 2012. ? !``````````````````````````````````````````````````````````````````````````````` 0. ! 10000. ! 0. ! 0. ! 1 2 4 0 0 0 0 0 !Nterms: ai*log(tau**ti); ai*tau**ti; ai*log(1-exp(bi*tau)); cosh; sinh 4.2430504 1.0 !ai, ti for [ai*log(tau**ti)] terms 5.9815241 0.0 !aj, ti for [ai*tau**ti] terms -0.52477835 1.0 5.2291378 -0.6718946781 !aj, ti for [ai*log(1-exp(ti*tau)] terms 19.549862 -2.0384051103 16.656178 -4.2991521793 5.9390291 -10.8428220875 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ #ETA !---Viscosity--- VS6 !Pure fluid viscosity model for p-xylene of Balogun et al. (2015). :DOI: 10.1063/1.4908048 ? ?``````````````````````````````````````````````````````````````````````````````` ?Balogun, B., Riesco, N., and Vesovic, V., ? "Reference Correlation of the Viscosity of para-Xylene from the Triple Point to 673 K and up to 110 MPa," ? J. Phys. Chem. Ref. Data, 44, 013103, 2015. ? doi: 10.1063/1.4908048 ? ?The overall uncertainty of the proposed correlation varies from 0.5% for the viscosity of the ? dilute gas and of liquid at ambient pressure to 5% for the viscosity at high pressures and ? temperatures. ? !``````````````````````````````````````````````````````````````````````````````` 286.4 !Lower temperature limit [K] 700.0 !Upper temperature limit [K] 110000.0 !Upper pressure limit [kPa] 8.166 !Maximum density [mol/L] 1 !Number of terms associated with dilute-gas function CI3 !Pointer to reduced effective collision cross-section model 1.0 !Lennard-Jones coefficient sigma [nm] not used here 1.0 !Lennard-Jones coefficient epsilon/kappa [K] not used here 1.0 1.0 !Reducing parameters for T, eta 0.220055 1.0 !Chapman-Enskog term 0.021357*SQRT(MW) 0 !Number of terms for initial density dependence 0 12 0 0 0 0 !# resid terms: close-packed density; simple poly; numerator of rational poly; denominator of rat. poly; numerator of exponential; denominator of exponential 616.168 2.69392 1.0 !Reducing parameters for T, rho, eta 35.779029 0.0 1.0 0. 0 -47.491003 -1.0 1.0 0. 0 11.80743 -2.0 1.0 0. 0 15.337 -0.5 2.166667 0. 0 122.919 0.0 2.166667 0. 0 -282.329 0.0 2.666667 0. 0 279.348 0.0 3.666667 0. 0 -146.776 0.0 4.666667 0. 0 28.361 0.0 5.666667 0. 0 -0.004585 0.0 11.666667 0. 0 -0.0004382 -0.5 11.666667 0. 0 0.00002307 -0.5 15.666667 0. 0 NUL !Pointer to the viscosity critical enhancement auxiliary function (none used) #AUX !---Auxiliary function for the collision integral CI3 !Collision integral model for p-xylene of Balogun et al. (2014). ? ?``````````````````````````````````````````````````````````````````````````````` ?Balogun, B., Riesco, N., and Vesovic, V., 2015. ? !``````````````````````````````````````````````````````````````````````````````` 0. ! 10000. ! 0. ! 0. ! 3 !Number of terms -1.4933 0 !Coefficient, power of Tstar 473.2 -1 -57033. -2 ================================================================================ #TCX !---Thermal conductivity--- TC1 !Pure fluid thermal conductivity model for p-xylene of Mylona et al. (2014). :DOI: 10.1063/1.4901166 ? ?``````````````````````````````````````````````````````````````````````````````` ?Mylona, S.K., Antoniadis, K.D., Assael, M.J. Huber, M.L., and Perkins, R.A., ? "Reference Correlation of the Thermal Conductivity of o-Xylene, m-Xylene, ? p-Xylene, and Ethylbenzene from the Triple Point to 700 K and Moderate Pressures," ? J. Phys. Chem. Ref. Data, 48, 043104, 2014. ? ?The estimated uncertainty for thermal conductivity of liquid and supercritical ? densities at temperatures from the triple point to 700 K is 3.6%, and 2.5% for the dilute gas. ? Uncertainty in the critical region is much larger. ? !``````````````````````````````````````````````````````````````````````````````` 286.4 !Lower temperature limit [K] 700.0 !Upper temperature limit [K] 200000.0 !Upper pressure limit [kPa] 10. !Maximum density [mol/L] 7 3 !# terms for dilute gas function: numerator, denominator 616.168 0.001 !Reducing parameters for T, tcx -3.88568 0. 29.4648 1. -81.5299 2. 77.1534 3. 7.55487 4. -3.8897 5. 0.406892 6. 0.00404188 0. -0.424893 1. 1.0 2. 10 0 !# terms for background gas function: numerator, denominator 616.168 2.69392 1. !Reducing parameters for T, rho, tcx -0.101022 0. 1. 0. 0.224828 0. 2. 0. -0.1591 0. 3. 0. 0.049949 0. 4. 0. -0.00562422 0. 5. 0. 0.107531 1. 1. 0. -0.205499 1. 2. 0. 0.150348 1. 3. 0. -0.0502584 1. 4. 0. 0.00644051 1. 5. 0. TK3 !Pointer to critical enhancement auxiliary function #AUX !---Auxiliary function for the thermal conductivity critical enhancement TK3 !Simplified thermal conductivity critical enhancement for p-xylene of Perkins et al. (2013). ? ?``````````````````````````````````````````````````````````````````````````````` ?Perkins, R.A., Sengers, J.V., Abdulagatov, I.M., and Huber, M.L., ? "Simplified Model for the Critical Thermal-Conductivity Enhancement in Molecular Fluids," ? Int. J. Thermophys., 34(2):191-212, 2013. doi: 10.1007/s10765-013-1409-z ? !``````````````````````````````````````````````````````````````````````````````` 0. ! 10000. ! 0. ! 0. ! 9 0 0 0 !# terms: terms, spare, spare, spare 1.0 1.0 1.0 !Reducing parameters for T, rho, tcx [mW/(m-K)] 0.63 !Nu (universal exponent) 1.239 !Gamma (universal exponent) 1.02 !R0 (universal amplitude) 0.063 !Z (universal exponent--not used for t.c., only viscosity) 1.0 !C (constant in viscosity eqn = 1/[2 - (alpha + gamma)/(2*nu)], but often set to 1) 0.235e-9 !Xi0 (amplitude) [m] 0.056 !Gam0 (amplitude) [-] 0.71e-9 !Qd_inverse (modified effective cutoff parameter) [m] 924.3 !Tref (reference temperature) [K] ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ @TRN !---ECS Transport--- ECS !Extended Corresponding States model (Propane reference); predictive mode for p-xylene. ? ?``````````````````````````````````````````````````````````````````````````````` ?*** ESTIMATION METHOD *** NOT STANDARD REFERENCE QUALITY *** ?Unpublished; uses method described in the following reference: ?Huber, M.L., Laesecke, A., and Perkins, R.A. ? "Model for the Viscosity and Thermal Conductivity of Refrigerants, Including ? a New Correlation for the Viscosity of R134a," ? Ind. Eng. Chem. Res., 42(13):3163-3178, 2003. doi: 10.1021/ie0300880 ? ?Estimated uncertainty for liquid viscosity at pressures to 110 MPa is 5% for 298 use estimates) 0.5813 !Lennard-Jones coefficient sigma [nm] for ECS method (estimated) 489.3 !Lennard-Jones coefficient epsilon/kappa [K] for ECS method (estimated) 1 0 0 !Number of terms in f_int term in Eucken correlation, spare1, spare2 0.00132 0. 0. 0. !Coefficient, power of T, spare1, spare2 3 0 0 !Number of terms in psi (visc shape factor): poly,spare1,spare2 0.312445906 0. 0. 0. !Coefficient, power of Tr, power of Dr, spare 0.403396269 0. 1. 0. !Coefficient, power of Tr, power of Dr, spare -0.0603026419 0. 2. 0. !Coefficient, power of Tr, power of Dr, spare 1 0 0 !Number of terms in chi (t.c. shape factor): poly,spare1,spare2 1.0 0. 0. 0. !Coefficient, power of Tr, power of Dr, spare TK3 !Pointer to critical enhancement auxiliary function ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #STN !---Surface tension--- ST1 !Surface tension model for p-xylene of Mulero et al. (2014). :DOI: 10.1063/1.4878755 ? ?``````````````````````````````````````````````````````````````````````````````` ?Mulero, A. and Cachadiņa, I., ? "Recommended Correlations for the Surface Tension of Several Fluids ? Included in the REFPROP Program," ? J. Phys. Chem. Ref. Data, 43, 023104, 2014. ? doi: 10.1063/1.4878755 ? !``````````````````````````````````````````````````````````````````````````````` 0. ! 10000. ! 0. ! 0. ! 1 !Number of terms in surface tension model 616.168 !Critical temperature used in fit (dummy) 0.0619 1.21 !Sigma0 and n #PS !---Vapor pressure--- PS5 !Vapor pressure equation for p-xylene of Herrig (2013). ? ?``````````````````````````````````````````````````````````````````````````````` ?Herrig, S., 2013. ? ?Functional Form: P=Pc*EXP[SUM(Ni*Theta^ti)*Tc/T] where Theta=1-T/Tc, Tc and Pc ? are the reducing parameters below, which are followed by rows containing Ni and ti. ? !``````````````````````````````````````````````````````````````````````````````` 0. ! 10000. ! 0. ! 0. ! 616.168 3531.5 !Reducing parameters 5 0 0 0 0 0 !Number of terms in equation -7.7221 1.0 1.5789 1.5 -13.035 3.8 18.453 4.6 -11.345 5.5 #DL !---Saturated liquid density--- DL1 !Saturated liquid density equation for p-xylene of Herrig (2013). ? ?``````````````````````````````````````````````````````````````````````````````` ?Herrig, S., 2013. ? ?Functional Form: D=Dc*[1+SUM(Ni*Theta^ti)] where Theta=1-T/Tc, Tc and Dc are ? the reducing parameters below, which are followed by rows containing Ni and ti. ? !``````````````````````````````````````````````````````````````````````````````` 0. ! 10000. ! 0. ! 0. ! 616.168 2.69392 !Reducing parameters 4 0 0 0 0 0 !Number of terms in equation 0.1783 0.15 3.4488 0.5 -2.3906 0.9 1.5933 1.3 #DV !---Saturated vapor density--- DV3 !Saturated vapor density equation for p-xylene of Herrig (2013). ? ?``````````````````````````````````````````````````````````````````````````````` ?Herrig, S., 2013. ? ?Functional Form: D=Dc*EXP[SUM(Ni*Theta^ti)] where Theta=1-T/Tc, Tc and Dc are ? the reducing parameters below, which are followed by rows containing Ni and ti. ? !``````````````````````````````````````````````````````````````````````````````` 0. ! 10000. ! 0. ! 0. ! 616.168 2.69392 !Reducing parameters 6 0 0 0 0 0 !Number of terms in equation -6.17784 0.653 -0.38825 0.17 -19.0575 2.6 -541.124 7.8 1251.55 8.9 -920.226 10.0 @END c 1 2 3 4 5 6 7 8 c2345678901234567890123456789012345678901234567890123456789012345678901234567890