Abdul-Fattah A. Asfour

Viscometric properties of multicomponent liquid n-alkane systems

The viscosities and densities of five quaternary and one quinary n-alkane systems were determined at several temperatures ranging from 293.15 to 313.15 K. The data were employed to test the original and the modified Generalized Corresponding States Principle (GCSP). Results showed that the modified GCSP provides significant improvement both in viscosity prediction and in viscosity correlation as compared with the original GCSP.

Viscosities and densities of eight binary 1-alkanol systems at 308.15 and 313.15 K

Abstract The viscosities and densities of eight 1-alkanol binary systems: 1-propanol–1-butanol, 1-propanol–1-pentanol, 1-butanol–1-pentanol, 1-butanol–1-nonanol, 1-butanol–1-decanol, 1-pentanol–1-octanol, 1-heptanol–1-octanol, and 1-decanol–1-undecanol, were measured over the entire composition range at 308.15 and 313.15 K and at atmospheric pressure. The viscosity data were correlated by the McAllister equation resulting in an average absolute error (AAD) 0.2% when the three-body model is used and 0.14% when the four-body model is employed. The viscosity data were also used to test the predictive capability of the Generalized Corresponding State Principle (GCSP) method. The resulting AAD was 0.96%.

Prediction of the viscosity of multi-component liquid mixtures : a generalized McAllister three-body interaction model

Abstract The work of Heric and Brewer (1969 Journal of Chemical Engineering Data , 14 , 55–63) which involved testing a number of liquid viscosity correlations resulted in concluding that the McAllister (1960 A.I.Ch.E. Journal , 6 , 427–431) model was the most accurate. However, the fact that the McAllister model is correlative in nature severely limits its practicality and usefulness. This is because costly and time-consuming data are required for the determination of the adjustable (or interaction) parameters contained in that model (Asfour, Cooper, Wu & Zahran, 1991, Industrial and Engineering Chemistry Research , 13 , 1666–1669). This study reports the development of a generalized expression of the McAllister model for multi-component liquid mixtures, evaluation of the generalized McAllister model parameters, converting the McAllister model into a predictive model, and comparison of the predictive capability of generalized McAllister model with those of the GC-UNIMOD reported by Cao, Knudsen, Fredenslund and Rasmussen (1993a,b Industrial and Engineering Chemistry Research , 32 , 2077–2087, 2088–2092) and with the generalized corresponding states principle (GCSP) which was reported by Teja and Rice (1981 Industrial and Engineering Chemistry, Fundamentals , 20 , 77–81). The comparison clearly indicated that the generalized McAllister model is consistently far superior to the GC-UNIMOD and the GCSP in predicting the viscosities of ternary, quaternary, and quinary liquid mixtures. This, no doubt, represents a significant accomplishment in the area of predicting the viscometric behaviour of multi-component liquid mixtures.

Viscometric properties of n-alkane liquid mixtures

Abstract The viscosities of C 8 - C 15 , n-alkane binary and ternary systems have been measured, over the entire composition range and at several temperature levels. Data have been utilized in validating a proposed modification of the Generalized Corresponding States Principle (GCSP) which was reported earlier by Teja and Rice (1981). The proposed modification of the GCSP provides flexible and reliable means for predicting the viscosities of multi-component n-alkane mixtures.

Composition dependence of densities and excess molar volumes of mixing of C8C15 n-alkane binary liquid systems at 308.15 and 313.15 K

Abstract The densities and excess molar volumes of eight n-alkane binary liquid systems: n-octane—n-undecane; n-octane—n-tetradecane; n-octane—n-pentadecane; n-decane—n-pentadecane; n-undecane—n-pentadecane; n-tridecane—n-pentadecane; n-decane—n-tridecane; n-undecane—n-tridecane were determined over the entire composition range at 308.15 and 313.15 K. All the excess molar volumes of mixing are negative or very close to zero. Generally, the absolute values of the excess molar volume of mixing increase with an increase in the difference between the number of carbon atoms of the components constituting the system.

Densities and excess molar volumes of eight n-alkane binary systems at 293.15 and 298.15 K

Densities and excess molar volumes of the following eight n-alkane binary liquid systems were measured over the entire composition range at 293.15 and 298.15 K and at atmospheric pressure: n-octane-n-undecane, n-octane-n-tridecane, n-octane-n-pentadecane, n-decane-n-pentadecane, n-undecane-n-pentadecane, n-tridecane-n-pentadacane, n-decane-n-tridecane and n-undecane-n-tridecane. All the excess molar volume values are negative. In general, it was found that the absolute values of the excess molar volumes of mixing increased with an increase in the difference of the number of carbon atoms of the components forming the system.

FLOW PROPERTIES OF LLOYDMINSTER AND COLD LAKE CRUDES

Data are presented on the viscosities of Cold Lake Crude and Lloydminster crude, over a temperature range of 278-323 K, up to a shear rate of 662 s−1 The effect of diluents on the flow properties has been measured and discussed. An Arrhenius-type relation between viscosity and temperature was verified and problems associated with the use of a Contraves Rheomat 30 viscometer were discussed, with respect to measurements of time-dependent material functions such as stress growth, stress relaxation and hysteresis behaviour.

Viscometric properties of eight binary liquid n-alkane systems at 308.15 and 313.15 K

Abstract Kinematic viscosity–composition data for eight n -alkane binary liquid systems, viz., octane+undecane, octane+tridecane, octane+pentadecane, decane+pentadecane, undecane+pentadecane, tridecane+pentadecane, decane+tridecane and undecane+tridecane, were measured over the entire composition range at 308.15 and 313.15 K and at atmospheric pressure. The data have been correlated by Herics model [E.L. Heric, J.G. Brewer, J. Chem. Eng. Data 12 (1967) 574–583.], as well as by the McAllister three-body interaction model [R.A. McAllister, AIChE J. 6 (1960) 427–431.].

An improved model for mass transfer in three-phase fluidized beds

Abstract A model for describing mass transfer in three-phase fluidized beds has been developed and tested using experimental data. The presence of two distinct mass transfer zones led to the idea of interfacing a plug flow model (PFM) with an axial dispersion model (ADM) at the separation boundary between these zones. The model has been validated for a wide range of operating conditions and proved to perform better than previous models.

Dependence of mutual diffusivities on concentration in liquid n-alkane binary mixtures at 25°C: A modification of the Asfour-Dullien equation

Abstract An equation has been obtained for predicting the dependence of mutual diffusivities on concentration in n-alkane binary liquid mixtures. The proposed equation results from a predictive equation that was developed for binary regular systems and reported earlier by the authors, after the incorporation of a concentration-dependent correction factor. The correction factor can be calculated from molecular parameters. The proposed equation has been tested using data available in the literature on four n-alkane binary systems. The predictive capability of the proposed equation is better than those of the existing equations of Vignes, Leffler and Cullinan, and Van Geet and Adamson.