Viscosity of pure liquids at high pressures

ECTP2014 - 20th European Conference on Thermophysical Properties
ORAL O_C2.15, 2 Sept. 11:45 – 12:00, Room_C
VISCOSITY OF PURE LIQUIDS AT HIGH PRESSURES; A CORRELATION SCHEME FOR A
SUSTAINABLE FAMILY OF COMPOUNDS
Helena M. N. T. Avelino1; João C. F. Diogo2; Fernando J. P. Caetano3; João M. N. A. Fareleira2
Centro de Química Estrutural, Instituto Superior Técnico and Instituto Superior de Engenharia de Lisboa, Portugal;
de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Portugal;
3Centro de Química Estrutural, Instituto Superior Técnico and Universidade Aberta, Portugal.
1
2Centro
Dialkyl adipates are “green” solvents currently used in a wide variety of applications, namely in the chemical, polymer
and mechanical industries. Many of these applications need their viscosity in order to optimize the processes in which
they are involved. Moreover, their main characteristics of stability, low toxicity, low vapour pressure and availability at
reasonably low cost suggest theycan also be used as viscosity reference liquids for industrial applications. Thus we
have developed a preliminary single correlation scheme of the viscosity of dialkyl adipates, in moderately wide ranges
of temperature and pressure.
The scheme is based on a semi-empirical method proposed by Li et al. [1] which is a heuristic development of the
kinetic theory for dense hard-sphere fluids, applied to the van der Waals model of a liquid [2]. Assael et al. [3] have
used the same hard-sphere model to correlate the transport properties of liquid n-alkanes. In the present
communication, we propose a correlation of the same type for the viscosity of liquid dialkyl adipates.
The method is based on recently obtained experimental viscosity and density data [4-6] of compressed liquid dialkyl
adipates, namely, dimethyl, dipropyl and dibutyl adipates. All the experimental viscosity data is described by the
present correlation scheme with a standard deviation of ± 0.5 %. The correlation scheme can be used to interpolate or
extrapolate viscosity data of dialkyl adipates that entered in the development of the method. Furthermore, tests will
be presented in order to assess its capability to estimate the viscosity of compressed liquid diethyl adipate, which was
not used to develop the technique, by comparison to recently published data [7,8]. The utilisation of the scheme as a
predictive tool makes use of a single molecular parameter for each dialkyl adipate.
Acknowledgements: This work was supported by the Strategic Projects PEst-OE/QUI/UI0100/2011 and PEstOE/QUI/UI0100/2013, both funded by Fundação para a Ciência e a Tecnologia (FCT, Portugal). Furthermore, J.C.F.D.
thanks FCT, Portugal, for his PhD grant (SFRH/BD/66736/2009).
[1] Li, S.F.Y.; Trengove, R.D.; Wakeham, W.A.; Zalaf, M., Int. J. Thermophys.1986, 7, 273–284.
[2] Dymond, J.H., Chem. Soc. Rev. 1985, 14, 317-356.
[3] Assael, M.J.; Dymond, J.H.; Papadaki, M.; Patterson, P.M., Int. J. Thermophys.1992, 13, 269–281.
[4] Diogo, J.C.F.; Caetano, F.J.P.; Fareleira, J.M.N.A., Fluid Phase Equilib. 2014, 367, 85–94.
[5] Diogo, J.C.F.; Avelino, H.M.N.T.; Caetano, F.J.P.; Fareleira, J.M.N.A., Fluid Phase Equilib. (Accepted) 2014.
[6] Diogo, J.C.F.; Caetano, F.J.P.; Fareleira, J.M.N.A., to be published.
[7] Comuñas, M. J. P.; Bazile, J.-P.; Lugo, L.; Baylaucq, A.; Fernández, J.; Boned, C., J. Chem. Eng. Data 2010, 55,
3697–3703.
[8] Meng, X.Y.; Zheng, P.J.; Wu, J.T.; Liu, Z.G. , J. Chem. Eng. Data 2008, 53,1474–1478.