Density and Viscosity for Mixtures of Athabasca Bitumen and Aromatic

Article pubs.acs.org/jced

Density and Viscosity for Mixtures of Athabasca Bitumen and Aromatic Solvents Jian Guo Guan, Mohammad Kariznovi, Hossein Nourozieh, and Jalal Abedi* Department of Chemical & Petroleum Engineering, University of Calgary, Calgary, Canada ABSTRACT: A new experimental apparatus was used to accurately measure the density and viscosity of aromatic solvents (toluene and xylenes), of Athabasca bitumen, and of their mixtures at different compositions. The measurements were taken under conditions applicable for both in situ recovery methods and pipeline transportation of heavy oil, that means, at temperatures varying from ambient temperature up to 343.15 K and at pressures up to 10 MPa and on mixtures with different weight fractions of the solvents (0.05, 0.1, 0.2, 0.3, 0.4, 0.5, and 0.6). The experimental density and viscosity data for the solvents and for raw bitumen were correlated using different correlation equations from the literature. Based on the experimental results, the influence of pressure, temperature, and solvent weight fraction on the density and viscosity of the mixtures was considered. The experimental density and viscosity data for the mixtures of Athabasca bitumen with toluene and xylenes were evaluated with predictive schemes as well as with correlation models representing certain mixing rules proposed in the literature. The density data are well predicted using an equation without adjustable parameter in which it is assumed that no volume change occurs. In contrast, the viscosity data are correlated reasonably over the studied conditions with Lederer’s and power law models which include one adjustable parameter each.

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INTRODUCTION Viscosity and density are essential thermophysical properties of hydrocarbon fluids, determining the fluid flow properties as well as the estimation of the total mass of reserves. In the design of any efficient chemical process or in the reduction of oil viscosity for enhanced oil recovery or pipeline transportation, a great deal of accurate viscosity and density data needs to be wellknown. The viscosity is more critical with highly viscous fluids, such as bitumen, in which the viscosity is in the order of million centipoises (mPa·s) at reservoir conditions. The production and pipeline transportation of such viscous fluids require the data on the viscosity and density of raw bitumen and diluted oil. Numerous studies on the measurements of bitumen viscosity and density have been reported in literature.1−9 Mehrotra and Svrcek2−7 reported the density and viscosity of different Alberta bitumens at atmospheric pressure. Mehrotra and Svrcek8,9 have also measured the viscosity data for the Athabasca and Cold Lake bitumens over the temperature range (313 to 393) K and at pressures up to 10 MPa. Recently, Badamchi-Zadeh et al.10,11 have reported the viscosity and density data for Athabasca bitumen at different temperatures and pressures. Alongside the experimental measurements, correlations for the density and viscosity of bitumen were also developed.8−12 Mehrotra and Svrcek8 developed a correlation for the viscosity of gas-free Athabasca bitumen as function of temperature and pressure. In another study,9 they did the same work for Cold Lake bitumen. Badamchi-Zadeh et al.10 predicted the density and viscosity of gas-free Athabasca bitumen. In addition, they correlated the density and viscosity of the saturated liquid phase at different temperatures and pressures for propane/bitumen system. For saturated phase densities, they correlated the data © 2013 American Chemical Society

on the assumption that no volume change occurs upon mixing. Khan et al.12 modified the Eyring and Hildebrand theories to predict the viscosity of Athabasca bitumen for the temperature range (293 to 403) K. The high viscous nature of bitumen necessitates dilution with gaseous solvents for production or liquid solvents for pipeline transportation. The production of viscosity-reduced bitumen is usually attained with an increase in the temperature and/or dilution with solvent. Dilution with a solvent can dramatically reduce the bitumen viscosity and the combined effect of solvent and heat can potentially and economically result in higher production rates. Thus, in addition to density and viscosity data of raw bitumen, data on the bitumen/solvent mixtures are essential for production and pipeline transportation. The data on gas-saturated bitumen and the diluted bitumen have been received much attention in last few decades.1−7,10,11,13−36 The impact of pressure and temperature on the solubility as well as on the diluted liquid density and viscosity has been evaluated. Although limited experimental data8,10 for the density and viscosity of Athabasca bitumen as a function of pressure have been reported, there is a lack of experimental data on the density and viscosity of mixtures containing bitumen and aromatic solvents. In this study, thus, we have focused on the mixtures of bitumen and aromatic solvents. The aim was to evaluate the effect of different parameters (temperature, pressure, and solvent weight fraction) on the physical properties of bitumen containing mixtures. Received: October 1, 2012 Accepted: January 2, 2013 Published: February 7, 2013 611

dx.doi.org/10.1021/je3010722 | J. Chem. Eng. Data 2013, 58, 611−624

Journal of Chemical & Engineering Data

Article

Figure 1. Schematic diagram of apparatus: (1) gas cylinder, (2) water tank, (3) vacuum pump, (4) reciprocating pump, (5) cleaning cell, (6) feeding cell, (7) pressure regulator, (8) density measuring cell, (9) viscometer, (10) pressure transducer, (11) temperature-controlled oven, (12) interface module, (13) density evaluation unit, (14) Viscopro 2000 unit, (15) personal computer.

Thus, in the present study, a new experimental apparatus was designed to accurately measure the physical properties of solvent, bitumen, and their mixtures in different compositions. These measurements were taken under conditions applicable for both in situ recovery methods and pipeline transportation of heavy oil. The experiments were conducted using Athabasca bitumen and aromatic solvents (toluene and xylenes) at temperatures varying from ambient up to 343.15 K and at pressures up to 10 MPa. The experimental density and viscosity data for the mixtures of Athabasca bitumen with toluene and xylenes were evaluated with predictive schemes as well as with correlation models representing certain mixing rules proposed in the literature.

The transducer is a Rosemount 3051CG5A capable of measuring the pressure in the range (−0.1 to 13.8) MPa. The value recorded by the in-line pressure transducer is reported as the system pressure. The density measuring cell is an Anton Paar vibrating tube densitometer with DMA HPM measuring cell. The measuring cell is equipped with an U-shaped Hastelloy tube into which the fluid is transferred. The tube is electronically vibrated at its characteristic frequency, and depending on the density of the fluid, the characteristic frequency changes. By precise determination of the characteristic frequency and a mathematical conversion, the density of the fluid will be calculated. The density measuring cell is designed to measure the density of liquids and gases [(0 to 3000) kg·m−3] over the pressure range (0 to 140) MPa and the temperature range (363 to 463) K. The density measuring cell was calibrated with water and nitrogen over the temperature and pressure ranges (295 to 333) K and atmospheric to 10 MPa, respectively. The data for the densities of nitrogen and water at specific temperatures and pressures were taken from the National Institute of Standards and Technology (NIST) database.37 The Cambridge viscometer is a flow-through sensor and capable of measuring the viscosity in the range of (0.25 to 20000) mPa·s and at pressures up to 14 MPa. The pistonstyle viscometer uses two magnetic coils within a stainless steel sensor and a magnetic piston inside the pipe line. The piston is forced magnetically back and forth within a predetermined distance. The piston travels through the process fluid in a chamber. The related traveling time of

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EXPERIMENTAL SECTION Apparatus. Figure 1 provides a schematic diagram of the experimental apparatus that we have used to measure the density and viscosity of bitumen−solvent mixtures. This apparatus consists of a feeding cell, a cleaning cell, a syringe 500d reciprocating ISCO pump, a vacuum pump, a viscometer, a density measuring cell, a pressure transducer, and a temperature-controlled oven. The density measuring cell, viscometer, and pressure transducer are placed inside the temperaturecontrolled air circulation oven. The viscometer and the measuring cell are the main parts of the entire system. The fluid was injected into the system and pressurized by the syringe 500d reciprocating ISCO pump. The system pressure in the viscometer and density meter was measured with an in-line pressure transducer. 612



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EXPERIMENTAL RESULTS Density and Viscosity of Solvents. Before any experiment for the binary mixtures of bitumen and solvent, the density and viscosity of the pure solvents were measured over wide range of temperature and pressure. The pure solvent density and viscosity data were measured to predict the mixture properties. The impact of pressure on the viscosity of the pure solvent was not significant here. Thus, the viscosity data were measured with respect to temperature and are listed in Table 2. As expected, the viscosity of the solvents reduces with temperature. The viscosity of toluene at a similar temperature and pressure was measured by Assael et al.38 and Byers and Williams39 and is listed in footnotes to Table 2. The measured viscosity values of toluene at atmospheric pressure are consistent with the reported values in the literature. The viscosity of pure solvents was fitted with a two-constant correlation,

the piston through the chamber is accurately measured and converted into the viscosity of interesting fluid. The viscometer is equipped with a SPC-372 sensor, which is factory calibrated. Materials. The toluene and xylenes were supplied by VWR international LLC. All of the chemicals were used without any further purification. The bitumen sample was provided from an Athabasca field, and the sample had been processed to remove sand and water. Table 1 summarizes the chemical sample specifications. Table 1. Chemical Sample Specifications chemical name toluene xylenes bitumen

source

CAS No.

initial purity (mass fraction)

purification method

VWR International LLC VWR International LLC Athabasca field

108-88-3

0.995

none

1330-20-7

0.985

none

Article

ln(μs ) = a + none

b T

(1)

where T is the temperature in K and μs is the viscosity in mPa·s. The results of the fitted correlations for the toluene and xylenes are presented in Table 2. The coefficients of the correlations are also mentioned as footnotes of Table 2. The average absolute relative deviations (AARD) were calculated as,

Procedure. Prior to each experiment, the entire system was cleaned. To remove any contaminant from the system, toluene was pumped into the system alternatively for couples of times. Then, the lines were flushed with nitrogen and evacuated using the vacuum pump. The binary mixtures of bitumen sample and solvent were prepared in the composition range 0.05, 0.1, 0.2, 0.2, 0.4, 0.5, and 0.6 mass fraction of solvent. For the preparation of samples, a Sartorius balance (model: LP4200S) with the measurement uncertainty of 0.01 g was used. The prepared mixtures had a weight of (300 to 400) g; therefore, the uncertainty introduced by the sample preparation for the composition was less than 0.0001 weight fraction for all mixtures. When the desired mixture was prepared, the sample was injected into the system using the feeding cell and syringe pump. The ISCO pump controller has the capability to set up precisely the desired pressure and discharge the sample fluid from the top of the cell to measuring chambers. The pressure during the measurements was controlled and kept constant with the pump at constant pressure mode. The in-line pressure transducer measured the exact system pressure. Now, the desired temperature was set with the temperature-controlled oven. After the desired temperature and pressure were fixed, the density and viscosity of mixture were recorded. Then, at constant temperature, the system pressure was increased to higher pressure. This procedure was repeated to cover the entire pressure range.

AARD(%) =

μcorr − μexp ⎛ 100 ⎞ ⎜ ⎟ ∑ ⎝ N ⎠ μexp

(2)

The AARDs for the toluene and xylenes correlations are 0.9 % and 0.6 %, respectively. The densities of pure toluene and xylenes were also measured, and the data are presented in Table 3, which shows that the densities of the solvents increase with pressure and reduce with temperature. The measured density values were correlated with the following equation,10 ρ = (a1 + a 2[T − 273.15])exp{(a3[T − 273.15] + a4)P} (3)

where T is the temperature in K, P is the pressure in kPa, and ρ is the density in kg·m−3. The fitted correlations represent the density of toluene within ± 0.2 kg·m−3 and the density of xylenes within ± 0.6 kg·m−3. The best fitted coefficients for the two solvents are summarized in Table 4. The density of toluene over the temperature range (214 to 363) K and at atmospheric pressure was measured by Assael et al.38 The measured results at the temperatures (303, 313, 323, and 333) K are listed in a footnote to Table 3. The measured density values of toluene at

Table 2. Measured μexp and Correlated μcorr Viscosities of Toluene and Xylenes at Different Temperatures T and Pressure of 0.124 MPaa toluene

xylene

T/K

μexp/(mPa·s)

μcorr/(mPa·s)

ARD (%)

T/K

μexp/(mPa·s)

μcorr/(mPa·s)

ARD (%)

341.6 330.2 319.8 308.3 300.5

0.343c 0.384 0.433 0.498d 0.530

0.344 0.385 0.430 0.490 0.538

0.3 0.3 0.7 1.6 1.5

342.7 330.9 317.5 306.2 299.1

0.356 0.412 0.482 0.551 0.605

0.359 0.409 0.478 0.552 0.608

0.8 0.7 0.8 0.2 0.5

b

Uncertainties u: u(T) = 0.1 K, u(P) = 0.007 MPa, and u(μ) = 0.02μ. bARD (%) = 100·|μcorr − μexp|/μexp; ln(μtoluene) = −4.3305 + 1115.1/T; ln(μxylenes) = −4.6304 + 1236/T. cAssael et al.38 reported 0.3491 mPa·s at 342.5 K. dByers and Williams39 reported 0.489 mPa·s at 308.2 K.

a

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Table 3. Measured Densities, ρexp, of Toluene and Xylenes at Different Temperatures T and Pressures Pa toluene

a

xylenes −3

toluene −3

xylenes −3

T/K

P/MPa

ρexp/(kg·m )

T/K

P/MPa

ρexp/(kg·m )

T/K

P/MPa

ρexp/(kg·m )

T/K

P/MPa

ρexp/(kg·m−3)

296.4 296.4 296.4 296.4 296.4 296.5 296.5 296.5 296.5 296.5 296.5 303.1 303.0 303.0 303.0 303.1 303.1 303.1 303.1 303.1 303.1 303.1 313.1 313.1 313.1 313.1 313.1 313.2

0.123 1.004 2.004 3.003 4.005 5.002 6.005 7.000 7.999 9.004 10.000 0.125 1.003 2.001 2.936 4.004 5.002 6.003 7.004 8.000 9.002 10.003 0.123 1.001 2.001 3.002 4.001 5.001

863.1 863.8 864.6 865.4 866.2 866.9 867.7 868.4 869.1 869.8 870.6 856.7b 857.5 858.3 859.1 859.9 860.7 861.5 862.3 863.0 863.8 864.5 847.3b 848.1 849.0 849.9 850.7 851.5

295.8 295.9 295.9 296.0 296.0 296.1 296.1 296.1 296.1 296.2 296.2 302.9 302.9 302.9 302.9 302.9 302.9 302.9 302.9 302.9 302.9 303.0 312.9 312.9 312.9 312.9 312.9 312.8

0.122 1.002 2.004 3.006 4.003 5.002 6.004 7.003 8.002 9.000 9.999 0.128 1.005 2.006 3.003 4.004 5.001 6.000 7.000 7.999 9.001 10.001 0.129 1.003 2.004 3.003 4.001 5.004

861.8 862.4 863.1 863.9 864.6 865.3 866.0 866.7 867.4 868.1 868.8 855.0 855.7 856.6 857.3 858.1 858.9 859.6 860.4 861.1 861.8 862.5 846.2 847.0 847.8 848.7 849.5 850.3

313.2 313.2 313.3 313.3 313.4 322.9 323.0 323.1 323.1 323.1 323.1 323.1 323.1 323.1 323.2 323.2 332.9 332.9 333.1 333.1 333.2 333.2 333.2 333.2 333.2 333.2 333.2

6.003 7.003 8.001 9.001 10.003 0.124 1.002 2.003 3.002 4.003 5.002 6.002 7.002 8.002 9.003 10.004 0.124 1.001 1.991 3.005 4.005 5.004 6.005 7.003 8.004 9.003 10.000

852.3 853.1 853.9 854.6 855.4 838.0b 838.9 839.8 840.7 841.7 842.6 843.4 844.3 845.1 845.9 846.7 828.8b 829.6 830.4 831.5 832.4 833.3 834.2 835.2 836.1 837.0 837.9

312.8 312.8 312.8 312.8 312.8 323.4 323.4 323.4 323.4 323.4 323.4 323.4 323.4 323.4 323.4 323.4 333.4 333.4 333.4 333.4 333.4 333.4 333.4 333.4 333.3 333.3 333.3

6.005 7.003 8.003 8.999 10.001 0.121 1.006 2.005 3.002 4.000 5.001 6.002 7.004 8.004 8.998 9.997 0.123 1.006 2.000 3.001 4.003 5.006 6.002 7.003 8.005 9.001 10.001

851.1 851.9 852.7 853.4 854.2 837.3 838.1 839.1 839.9 840.8 841.6 842.5 843.3 844.1 844.9 845.7 828.8 829.6 830.7 831.6 832.5 833.4 834.3 835.2 836.0 836.9 837.7

Uncertainties u: u(T) = 0.1 K, u(P) = 0.007 MPa, and u(ρ) = 0.1 kg·m−3. bAssael et al.38 reported 856.5 kg·m−3 at 303.8 K, 847.9 kg·m−3 at 312.9 K, 838.5 kg·m−3 at 322.8 K, and 829.2 kg·m−3 at 332.6 K and at atmospheric pressure each.

The measured and correlated densities are plotted in Figure 2 with respect to pressure at different temperatures. As expected, the density of bitumen increases with pressure at constant temperature. This behavior is observed for all temperatures and linear trends for the variation of density with pressure are seen. The impact of temperature on the bitumen density is also demonstrated in Figure 2. At constant pressure, the bitumen density reduces with temperature. The variation of bitumen density with temperature can also be further investigated by plotting the density with respect to temperature. In this case similar to density/ pressure plot, linear trends were obtained. Thus, the bitumen density shows linear variations with pressure and temperature. Viscosity of Bitumen. The viscosity of the bitumen was also measured at four temperatures of (342, 331, 320, and 309) K over the pressure range atmospheric to 10 MPa. The measured data are summarized in Table 7. The viscosity data were fitted with the two correlations developed by Mehrotra and Svrcek.8 The correlations take into account the impact of pressure and temperature on the bitumen viscosity and the authors examined the developed correlations for their viscosity measurements over the temperature and pressure ranges of (313 to 393) K and (0 to 10) MPa. Mehrotra and Svrcek8 presented the following two empirical correlations for the viscosity of solvent-free bitumen,

Table 4. Coefficients of the Correlation Equation for the Density of Toluene and Xylenes (eq 3) coefficients in eq 3

a1

a2

a3

a4

toluene xylenes

884.86 881.46

−0.9399 −0.8834

7.1697·10−9 6.8014·10−9

7.1437·10−7 7.063·10−7

atmospheric pressure are consistent with the reported values by Assael et al.38 Density of Bitumen. The density of the bitumen was measured over wide range of temperature by the Anton Paar density measuring cell. The temperature was varied within ± 0.1 K, and the pressure was controlled with the ISCO pump. The uncertainty of the pressure and the density measurements was 7 kPa and 0.1 kg·m−3, respectively. The measured density data at the temperatures (296, 303, 313, 323, and 333) K over the pressure range atmospheric to 10 MPa are listed in Table 5 along with the correlated values obtained using eq 3. The regression of the coefficients was performed using a MATLAB subroutine. Table 6 summarizes the best fitted coefficients. The correlated values show a maximum deviation of ± 0.3 kg·m−3 from the measured ones. Badamchi-Zadeh et al.10 also measured the density of Athabasca bitumen at three different pressures (90, 1470, and 3540) kPa over the temperature range (283 to 323) K. The authors fitted their measurements with eq 3. The coefficients obtained by Badamchi-Zadeh et al.10 are also mentioned in Table 6 for comparison. 614

ln(μB ) = exp[b1 + b2 ln(T )] + b3(P − 0.090)

(4)

ln(ln(μB )) = [b1 + b2 ln(T )] + b3(P − 0.090)

(5)



Article

Table 5. Measured ρexp and Correlated ρcorr Density of Athabasca Bitumen at Different Temperatures T and Pressures Pa T/K

P/MPa

ρexp/(kg·m−3)

ρcorr/(kg·m−3)

Δρ/(kg·m‑3)b

296.0 296.1 296.2 296.3 296.3 296.4 296.4 296.4 296.4 296.5 296.5 302.8 303.2 303.3 303.4 303.4 303.6 303.6 303.6 303.6 303.6 303.6 313.4 313.3 313.2 313.2 313.2 313.2 313.2 313.1 313.1 313.1 313.1 323.2 323.2 323.3 323.3 323.3 323.3 323.3 323.4 323.4 323.4 323.4 332.8 333.0 333.0 333.0 333.0 333.0 333.0 333.0 333.0 333.0

0.127 1.003 2.001 3.003 4.004 4.996 5.997 6.998 7.995 8.995 9.992 0.123 1.005 2.003 2.998 4.002 5.000 5.999 6.999 7.996 8.999 9.995 0.129 1.003 2.000 3.000 4.000 5.002 5.997 6.998 7.998 8.996 9.997 0.123 1.001 2.000 2.998 4.003 4.999 6.000 6.996 7.995 8.993 9.997 0.121 1.004 3.002 4.003 4.995 6.001 6.994 8.001 8.995 9.996

1006.1 1006.5 1006.8 1007.3 1007.8 1008.4 1008.9 1009.4 1009.9 1010.3 1010.7 1001.5 1001.7 1002.2 1002.7 1003.2 1003.7 1004.2 1004.7 1005.2 1005.7 1006.1 994.9 995.4 996.0 996.6 997.2 997.7 998.2 998.7 999.2 999.8 1000.2 988.7 989.2 989.8 990.3 990.9 991.4 992.0 992.5 993.0 993.5 994.1 982.7 983.2 984.4 985.0 985.6 986.2 986.7 987.3 987.8 988.4

1006.0 1006.3 1006.8 1007.2 1007.7 1008.2 1008.7 1009.2 1009.7 1010.1 1010.6 1001.7 1001.9 1002.3 1002.8 1003.3 1003.7 1004.2 1004.7 1005.3 1005.8 1006.3 995.0 995.5 996.1 996.7 997.2 997.7 998.3 998.9 999.4 999.9 1000.5 988.8 989.3 989.8 990.3 990.9 991.5 992.0 992.5 993.1 993.6 994.2 982.7 983.1 984.3 984.8 985.4 986.0 986.6 987.2 987.7 988.3

−0.2 −0.2 0.0 −0.1 −0.1 −0.2 −0.2 −0.2 −0.2 −0.2 −0.1 0.2 0.2 0.1 0.1 0.1 0.0 0.0 0.0 0.0 0.1 0.2 0.1 0.1 0.1 0.0 0.0 0.0 0.1 0.2 0.2 0.1 0.3 0.1 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.1 0.1 0.1 0.0 −0.1 −0.1 −0.2 −0.2 −0.2 −0.1 −0.1 −0.1 −0.1

Table 6. Coefficients of the Correlation Equation for the Density of Athabasca Bitumen (eq 3) coefficients in eq 3 this study Badamchi-Zadeh et al.10

a1

a2

a3

a4

1020.30 1020.0

−0.63096 −0.6317

2.27016·10−9 2.521·10−9

4.49743·10−7 6.8072·10−7

Figure 2. Density of Athabasca bitumen ρ as a function of pressure P at different temperatures T. Measured densities: ◆, 296 K; ■, 303 K; ▲, 313 K; ○, 323 K; ×, 333 K. ---, correlated densities using eq 3.

measured to be 0.090 MPa in this study. The constants for eqs 4 and 5 are summarized in Table 8 along with the coefficients fitted by other authors for Athabasca bitumen. The correlated data for the two viscosity correlations using the coefficients mentioned in Table 8 are also listed in Table 7. The last column of Table 7 shows the absolute relative deviation between the measured data and the correlated values. The AARDs are 2.1 % and 1.7 % for eqs 4 and 5, respectively. Figure 3 shows the measured and the correlated viscosity data versus pressure at different temperatures for Athabasca bitumen. In this plot, the dashed lines denote the correlated results by eqs 4 and 5, and the symbols show the experimental data. The figure illustrates that the viscosity of bitumen increases with pressure and decreases with temperature. The impact of temperature on the bitumen viscosity is more pronounced than the effect of pressure. As depicted in Figure 3, the viscosity data are well fitted with the two empirical correlations. The results of the two models at low pressures are the same. However, as the pressure increases, the deviation of the two models from each other is more pronounced. Overall, the two models correlate the viscosity data well over the studied pressure and temperature ranges. Nevertheless, on the basis of AARDs, eq 5 results in lower deviations. Density and Viscosity of Mixtures. The density and viscosity of bitumen diluted with toluene and xylenes were measured at different temperatures, pressures, and solvent weight fractions. The aim was to evaluate the impact of variations in pressure, temperature, and solvent weight fraction on the viscosity and density of the mixture. The data for the density of mixtures prepared from toluene and bitumen are summarized in Table 9. The same measurements for bitumen/xylenes mixtures were also conducted and are listed in Table 10. Generally, the density of bitumen/ toluene and bitumen/xylenes mixtures reduces with the increase in temperature and solvent weight fraction, while the pressure raises the density of the mixtures. Tables 11 and 12

a Uncertainties u: u(T) = 0.1 K, u(P) = 0.007 MPa, and u(ρ) = 0.1 kg·m−3. bΔρ = (ρcorr − ρexp).

in which μB is the bitumen viscosity in mPa·s, T is the temperature in K, and P is the pressure in MPa. The atmospheric pressure was 615



Article

Table 7. Measured μexp and Correlated μcorr Viscosity of Athabasca Bitumen at Different Temperatures T and Pressures Pa μcorr/(mPa·s)

ARD (%)b

P/MPa

T/K

μexp/(mPa·s)

eq 4

eq 5

eq 4

eq 5

0.124 1.002 2.002 4.000 4.999 5.998 6.997 7.996 8.995 9.994 0.124 1.002 2.002 3.001 4.000 4.999 5.998 6.997 7.996 8.995 9.994 0.124 1.002 2.002 3.001 4.000 4.999 5.998 6.997 7.996 8.995 9.994 0.124 1.002 2.002 3.001

342.2 341.1 342.0 342.2 341.8 342.6 342.3 342.6 342.7 342.8 330.0 331.3 330.3 331.5 331.6 331.6 331.6 331.6 331.7 331.7 331.7 319.5 319.8 319.9 319.9 319.9 319.9 319.9 319.8 319.9 319.9 319.9 308.7 308.8 308.9 309.0

1236 1465 1499 1561 1708 1643 1765 1789 1859 1944 3619 3519 3945 3728 3876 4053 4246 4433 4621 4848 5061 10499 11135 11882 12446 12869 13342 13843 14590 15184 16119 17048 36164 38371 40237 41420

1291 1471 1438 1562 1693 1670 1795 1842 1919 2000 3688 3413 3933 3696 3847 4040 4244 4457 4639 4872 5117 10686 10798 11219 11783 12376 12998 13652 14495 15059 15817 16612 38547 39730 41198 42718

1324 1497 1454 1557 1677 1642 1756 1789 1853 1920 3718 3440 3954 3712 3857 4046 4244 4454 4632 4863 5108 10564 10722 11191 11810 12468 13166 13908 14860 15533 16424 17371 37116 38659 40575 42592

4.5 0.4 4.0 0.1 0.9 1.6 1.7 3.0 3.2 2.9 1.9 3.0 0.3 0.8 0.7 0.3 0.1 0.5 0.4 0.5 1.1 1.8 3.0 5.6 5.3 3.8 2.6 1.4 0.7 0.8 1.9 2.6 6.6 3.5 2.4 3.1

7.1 2.2 3.0 0.3 1.8 0.1 0.5 0.0 0.3 1.3 2.7 2.2 0.2 0.4 0.5 0.2 0.0 0.5 0.2 0.3 0.9 0.6 3.7 5.8 5.1 3.1 1.3 0.5 1.8 2.3 1.9 1.9 2.6 0.8 0.8 2.8

Figure 3. Viscosity of Athabasca bitumen μ as a function of pressure P at different temperatures T. Measured viscosities: ◆, 342.2 K; ○, 331.2 K; ▲, 319.8 K; ■, 308.9 K. , correlated viscosities using eq 4; ---, correlated viscosities using eq 5.

the simple structure of the solvent compared to bitumen. On the other hand, bitumen shows a stronger change in viscosity when the pressure varies. Thus, any mixture prepared from the species of bitumen and aromatic solvents shows a behavior similar to bitumen at low solvent weight fraction. The impact of pressure on mixture viscosity is also dependent on the temperature. That is, at lower temperatures, the pressure would result in higher viscosity variations. This trend is also observed for the solvent-free-bitumen data presented above. The bitumen viscosity demonstrates higher variations with pressure at lower temperatures. As previously mentioned, the density of mixture is increased with the pressure and reduced with solvent weight fraction and temperature. The impacts of pressure and solvent weight fraction on the mixture density follow linear trends. More details on these variations will be discussed in the next few paragraphs. The generated density data of the mixtures are predicted with the following equation, 1 ρm = w 1−w s + ρ s ρ s

Uncertainties u: u(T) = 0.1 K, u(P) = 0.007 MPa, and u(μ) = 0.02 μ. b ARD (%) = 100·|μcorr − μexp|/μexp. a

coefficients

Mehrotra and Svrcek8

eq eq eq eq

4 5 4 5

b1

b2

b3

23.95318 23.55379 23.42920 22.85150

−3.76743 −3.69839 −3.67720 −3.57840

0.049118 0.005766 0.0345755 0.00511938

(6)

where ws is the weight fraction of solvent and ρs and ρB are the densities of solvent and bitumen, respectively. This equation was developed on the basis of the assumption that no volume change occurs upon mixing. Density values were calculated using the above equation. The predicted results are in good agreement with the measured data, within 0.04 % AARD for bitumen/toluene and 0.06 % AARD for bitumen/xylene mixtures. The densities of the pure solvent and raw bitumen at each temperature and pressure were calculated using eq 3 with the coefficients summarized in Tables 4 and 6. Figure 4 shows the variations of mixture density with the xylenes weight fraction at different temperatures and at the highest pressure (i.e., 10 MPa). The symbols are measured experimental data, and lines are the predictions using eq 6. The figure illustrates that the data agree well with the predictions. The mixture density is linearly decreased with solvent weight fraction. This trend is observed for all temperatures and pressures considered in this study. To evaluate the impact of pressure on the mixture density, the density data are plotted versus pressure at different temperatures in Figure 5. For this plot, the weight fraction of

Table 8. Coefficients of the Correlation Equations for the Viscosity of Athabasca Bitumen (eqs 4 and 5) this study

B

present the viscosity data of bitumen/toluene and bitumen/ xylenes mixtures, respectively. The impact of pressure on the mixture viscosity is more pronounced at lower solvent weight fractions. This behavior is expected; if the solvent weight fraction becomes higher, the behavior of mixture would be more similar to the pure solvent. The viscosity data of the pure solvent presented in the first part of the Experimental Results section indicate that the viscosity of the solvent is not significantly affected by the pressure due to 616



Article

Table 9. Measured Densities of Bitumen and Toluene Mixtures ρm at Different Temperatures T and Pressures P; ws, Weight Fraction of Toluene in Mixturea ws = 0.05

a

ws = 0.1

ws = 0.2

ws = 0.3

ws = 0.4

ws = 0.5

ws = 0.6

P

T

ρm

T

ρm

T

ρm

T

ρm

T

ρm

T

ρm

T

ρm

MPa

K

kg·m−3

K

kg·m−3

K

kg·m−3

K

kg·m−3

K

kg·m−3

K

kg·m−3

K

kg·m−3

0.125 0.125 0.125 0.125 0.125 1.002 1.002 1.002 1.002 1.002 2.003 2.003 2.003 2.003 2.003 3.001 3.001 3.001 3.001 3.001 4.000 4.000 4.000 4.000 4.000 4.999 4.999 4.999 4.999 4.999 5.999 5.999 5.999 5.999 5.999 6.997 6.997 6.997 6.997 6.997 7.996 7.996 7.996 7.996 7.996 8.994 8.994 8.994 8.994 8.994 9.994 9.994 9.995 9.995 9.995

296.6 303.5 312.9 323.3 333.1 296.6 303.5 313.1 323.3 333.1 296.6 303.5 313.1 323.3 333.2 296.6 303.5 313.2 323.3 333.2 296.6 303.5 313.3 323.3 333.1 296.6 303.5 313.3 323.3 333.1 296.6 303.5 313.2 323.3 333.1 296.6 303.5 313.2 323.3 333.1 296.6 303.5 313.2 323.3 333.1 296.6 303.5 313.2 323.2 333.1 296.6 303.5 313.1 323.2 333.1

997.4 992.5 986.4 979.8 973.8 997.8 993.0 986.8 980.3 974.3 998.4 993.5 987.4 980.9 974.9 999.0 994.1 987.9 981.5 975.5 999.5 994.7 988.4 982.1 976.2 1000.0 995.2 989.0 982.7 976.8 1000.6 995.7 989.6 983.3 977.4 1001.0 996.3 990.2 983.9 978.0 1001.5 996.8 990.7 984.5 978.6 1002.0 997.3 991.3 985.0 979.1 1002.5 997.8 991.8 985.5 979.6

296.8 303.5 313.1 323.3 333.0 296.8 303.5 313.1 323.2 333.0 296.8 303.5 313.2 323.2 333.1 296.8 303.5 313.1 323.3 333.1 296.8 303.5 313.2 323.2 333.1 296.9 303.5 313.2 323.2 333.1 296.9 303.5 313.2 323.2 333.1 296.9 303.5 313.2 323.2 333.1 296.9 303.5 313.2 323.2 333.1 296.9 303.5 313.2 323.2 333.0 296.9 303.5 313.2 323.3 333.1

988.8 984.5 978.3 971.6 965.3 989.3 985.0 978.7 972.1 965.8 989.9 985.6 979.4 972.9 966.5 990.5 986.3 980.0 973.4 967.1 991.0 986.8 980.5 974.0 967.7 991.5 987.4 981.1 974.7 968.3 992.1 988.0 981.7 975.3 969.0 992.6 988.5 982.2 975.9 969.6 993.1 989.0 982.8 976.3 970.2 993.5 989.5 983.3 976.9 970.8 994.1 990.0 983.8 977.4 971.3

296.3 303.4 313.2 323.3 333.3 296.3 303.4 313.1 323.3 333.3 296.3 303.4 313.2 323.3 333.3 296.4 303.4 313.3 323.3 333.3 296.4 303.5 313.3 323.3 333.3 296.4 303.5 313.1 323.3 333.3 296.4 303.5 313.0 323.3 333.3 296.4 303.5 313.0 323.3 333.3 296.4 303.1 313.1 323.3 333.3 296.5 303.1 313.2 323.3 333.3 296.5 303.2 313.3 323.3 333.3

973.5 968.8 961.9 954.9 948.1 974.0 969.3 962.6 955.4 948.6 974.6 969.9 963.0 956.1 949.3 975.1 970.6 963.6 956.8 950.0 975.7 971.1 964.3 957.5 950.7 976.3 971.6 965.1 958.0 951.4 976.8 972.2 965.7 958.7 952.0 977.4 972.8 966.3 959.3 952.6 977.9 973.6 966.7 959.9 953.3 978.4 974.1 967.2 960.5 953.9 978.9 974.5 967.7 961.1 954.5

296.5 303.2 313.1 323.3 333.2 296.5 303.3 313.1 323.3 333.1 296.5 303.3 313.1 323.3 333.1 296.5 303.4 313.1 323.4 333.2 296.6 303.4 313.1 323.4 333.2 296.6 303.4 313.1 323.4 333.2 296.7 303.5 313.1 323.4 333.1 296.7 303.2 313.1 323.3 333.1 296.8 303.3 313.1 323.3 333.1 296.8 303.3 313.1 323.3 333.2 296.8 303.4 313.1 323.3 333.2

958.1 952.9 945.8 938.4 931.5 958.6 953.4 946.4 939.0 932.3 959.2 954.1 947.1 939.8 933.1 959.9 954.7 947.7 940.5 933.8 960.4 955.3 948.4 941.2 934.5 960.9 955.9 949.0 941.8 935.2 961.5 956.5 949.7 942.5 935.9 962.0 957.2 950.3 943.2 936.6 962.5 957.8 950.9 943.8 937.2 963.1 958.3 951.5 944.5 937.8 963.7 958.8 952.0 945.0 938.4

297.0 303.4 313.3 323.2 333.2 297.0 303.5 313.3 323.2 333.2 297.0 303.5 313.3 323.2 333.3 297.0 303.4 313.3 323.2 333.2 297.0 303.4 313.3 323.2 333.2 296.9 303.3 313.3 323.2 333.2 296.9 303.2 313.3 323.2 333.3 296.9 303.2 313.3 323.1 333.3 296.9 303.2 313.3 323.2 333.3 296.9 303.2 313.3 323.2 333.3 296.9 303.2 313.3 323.2 333.3

942.9 938.0 930.5 923.3 915.9 943.5 938.5 931.1 923.9 916.6 944.1 939.1 931.8 924.6 917.3 944.8 939.8 932.5 925.3 918.3 945.4 940.5 933.2 926.0 918.9 946.1 941.3 933.9 926.7 919.6 946.7 941.9 934.5 927.5 920.3 947.3 942.5 935.2 928.2 921.0 947.9 943.2 935.8 928.8 921.7 948.5 943.7 936.5 929.5 922.4 949.1 944.3 937.1 930.1 923.1

296.0 303.0 313.0 323.2 333.4 296.1 303.0 313.1 323.2 333.4 296.1 303.0 313.1 323.2 333.4 296.1 303.0 313.1 323.2 333.3 296.2 303.0 313.1 323.2 333.3 296.2 303.0 313.1 323.2 333.2 296.2 303.0 313.1 323.2 333.2 296.2 303.0 313.2 323.2 333.2 296.2 303.0 313.2 323.2 333.2 296.3 303.0 313.2 323.2 333.3 296.3 303.0 313.2 323.2 333.3

929.1 923.6 915.7 907.9 900.1 929.7 924.3 916.3 908.6 900.8 930.3 925.0 917.0 909.4 901.7 931.0 925.6 917.7 910.2 902.7 931.6 926.3 918.4 910.9 903.5 932.3 926.9 919.1 911.7 904.2 932.9 927.6 919.8 912.4 905.0 933.5 928.2 920.4 913.1 905.7 934.1 928.9 921.1 913.8 906.5 934.7 929.5 921.8 914.5 907.1 935.3 930.1 922.4 915.2 907.9

296.0 302.9 313.1 323.2 333.2 296.0 302.9 313.1 323.2 333.1 296.0 302.9 313.1 323.2 333.2 296.0 302.9 313.1 323.1 333.2 296.0 302.9 313.1 323.1 333.2 296.0 302.9 313.1 323.1 333.3 296.0 302.9 313.1 323.2 333.3 296.1 302.9 313.1 323.2 333.3 296.1 302.9 313.2 323.2 333.4 296.1 302.9 313.2 323.2 333.3 296.1 302.9 313.2 323.2 333.3

915.1 909.5 901.2 893.0 885.2 915.8 910.1 901.9 893.8 885.8 916.5 910.8 902.7 894.7 886.5 917.1 911.5 903.4 895.4 887.4 917.8 912.2 904.2 896.2 888.2 918.4 912.9 904.9 897.0 889.0 919.1 913.6 905.6 897.7 889.7 919.8 914.3 906.3 898.5 890.6 920.4 914.9 907.0 899.2 891.4 921.0 915.6 907.6 899.9 892.2 921.6 916.2 908.3 900.6 893.0

Uncertainties u: u(T) = 0.1 K, u(P) = 0.007 MPa, u(ws) = 0.0001, and u(ρm) = 0.5 kg·m−3. 617



Article

Table 10. Measured Densities of Bitumen and Xylene Mixtures ρm at Different Temperatures T and Pressures P; ws, Weight Fraction of Xylenes in Mixturea ws = 0.05

a

ws = 0.1

ws = 0.2

ws = 0.3

ws = 0.4

ws = 0.5

ws = 0.6

P

T

ρm

T

ρm

T

ρm

T

ρm

T

ρm

T

ρm

T

ρm

MPa

K

kg·m−3

K

kg·m−3

K

kg·m−3

K

kg·m−3

K

kg·m−3

K

kg·m−3

K

kg·m−3

0.125 0.125 0.125 0.125 0.125 1.003 1.003 1.003 1.003 1.003 2.000 2.000 2.000 2.000 2.000 3.001 3.001 3.001 3.001 3.001 4.001 4.001 4.001 4.001 4.001 4.998 4.998 4.998 4.998 4.998 5.997 5.997 5.997 5.997 5.997 6.996 6.996 6.996 6.996 6.996 7.997 7.997 7.997 7.997 7.997 8.996 8.996 8.996 8.996 8.996 9.995 9.995 9.995 9.995 9.995

296.4 303.3 313.4 322.9 333.1 296.5 303.4 313.2 322.9 333.2 296.5 303.4 313.2 322.9 333.2 296.5 303.4 313.1 323.0 333.2 296.5 303.4 313.1 323.0 333.2 296.5 303.3 313.0 323.0 333.2 296.6 303.1 313.0 323.0 333.2 296.6 303.1 313.0 323.0 333.2 296.6 303.1 313.0 323.0 333.3 296.7 303.1 313.0 323.0 333.3 296.7 303.2 313.0 323.0 333.3

997.1 992.5 985.9 980.0 973.9 997.6 993.0 986.4 980.6 974.4 998.1 993.6 987.0 981.2 975.0 998.6 994.1 987.7 981.8 975.6 999.2 994.6 988.4 982.4 976.2 999.7 995.2 989.0 982.9 976.8 1000.2 995.9 989.6 983.5 977.4 1000.7 996.5 990.1 984.0 978.0 1001.2 997.0 990.7 984.6 978.6 1001.6 997.4 991.2 985.1 979.1 1002.1 997.9 991.7 985.7 979.7

296.5 302.9 313.3 323.5 332.8 296.5 303.0 313.2 323.5 332.9 296.5 303.0 313.2 323.5 333.0 296.5 303.0 313.2 323.5 333.0 296.5 303.0 313.2 323.5 333.1 296.5 303.0 313.2 323.5 333.1 296.5 303.0 313.2 323.4 333.1 296.5 303.1 313.2 323.4 333.1 296.5 303.1 313.2 323.4 333.2 296.5 303.1 313.2 323.4 333.2 296.5 303.2 313.2 323.4 333.2

988.8 984.4 977.7 971.2 965.4 989.3 984.9 978.3 971.7 966.0 989.9 985.5 978.9 972.4 966.6 990.4 986.0 979.5 973.0 967.2 991.0 986.6 980.1 973.6 967.8 991.5 987.1 980.6 974.2 968.4 992.0 987.6 981.2 974.8 969.0 992.5 988.2 981.7 975.4 969.6 993.0 988.6 982.3 976.0 970.1 993.5 989.1 982.8 976.5 970.7 994.0 989.6 983.4 977.1 971.2

296.8 303.4 313.0 323.3 333.2 296.8 303.4 313.0 323.3 333.3 296.8 303.4 313.0 323.3 333.3 296.9 303.5 313.0 323.3 333.3 296.9 303.5 313.0 323.3 333.3 296.9 303.5 313.0 323.3 333.3 296.9 303.5 313.0 323.3 333.3 296.9 303.5 313.0 323.3 333.3 296.9 303.5 313.0 323.3 333.3 296.9 303.5 313.0 323.3 333.3 296.9

972.5 967.9 961.0 953.9 947.1 973.0 968.3 961.6 954.3 947.5 973.6 969.0 962.2 955.0 948.3 974.2 969.6 962.8 955.6 948.9 974.7 970.1 963.4 956.2 949.6 975.3 970.6 964.0 956.9 950.2 975.8 971.2 964.6 957.5 950.9 976.4 971.8 965.2 958.1 951.5 976.9 972.4 965.7 958.7 952.1 977.4 972.9 966.3 959.3 952.7 978.0

313.1 323.3 333.3

966.8 959.9 953.3

296.9 303.3 313.0 323.4 333.2 296.9 303.3 313.0 323.4 333.2 296.9 303.3 313.0 323.4 333.2 296.9 303.3 313.0 323.4 333.2 296.9 303.3 313.0 323.4 333.2 296.9 303.3 313.0 323.4 333.2 297.0 303.3 313.0 323.4 333.3 297.0 303.3 313.0 323.5 333.3 297.0 303.3 313.1 323.5 333.3 297.0 303.3 313.1 323.5 333.3 297.0 303.3 313.1 323.5 333.3

955.4 951.1 944.5 937.5 931.4 955.9 951.7 945.0 938.1 932.1 956.5 952.5 945.7 938.8 932.8 957.1 953.1 946.3 939.5 933.5 957.7 953.7 946.9 940.2 934.1 958.3 954.3 947.6 940.8 934.8 958.8 954.9 948.2 941.4 935.5 959.4 955.5 948.8 942.0 936.1 960.0 956.0 949.4 942.7 936.8 960.5 956.6 949.9 943.3 937.4 961.1 957.1 950.5 943.9 938.0

296.5 303.2 312.8 323.2 333.2 296.5 303.2 312.9 323.3 333.2 296.5 303.2 312.9 323.3 333.1 296.5 303.2 312.9 323.3 333.2 296.5 303.2 312.9 323.3 333.2 296.5 303.2 312.9 323.3 333.2 296.5 303.2 312.9 323.2 333.1 296.5 303.2 312.9 323.2 333.1 296.5 303.2 313.0 323.2 333.1 296.5 303.2 313.0 323.3 333.1 296.5 303.2 313.0 323.3 333.1

942.6 937.7 930.6 923.0 916.2 943.2 938.3 931.1 923.6 916.8 943.8 938.9 931.8 924.4 917.6 944.4 939.6 932.5 925.0 918.2 945.1 940.2 933.1 925.7 918.8 945.7 940.8 933.8 926.4 919.5 946.2 941.5 934.4 927.0 920.3 946.8 942.1 935.0 927.7 921.0 947.4 942.7 935.6 928.4 921.7 948.0 943.3 936.2 928.9 922.4 948.5 943.8 936.8 929.5 923.0

296.4 303.0 313.1 323.2 333.1 296.4 303.0 313.1 323.2 333.1 296.4 303.0 313.1 323.2 333.1 296.4 303.0 313.1 323.2 333.1 296.4 303.0 313.1 323.2 333.1 296.4 303.1 313.1 323.2 333.1 296.4 303.1 313.1 323.2 333.1 296.4 303.1 313.1 323.2 333.1 296.4 303.2 313.1 323.2 333.1 296.4 303.2 313.1 323.2 333.2 296.4 303.2 313.1 323.2 333.2

928.2 923.0 915.6 907.9 900.8 928.8 923.7 916.2 908.6 901.5 929.4 924.3 916.9 909.2 902.3 930.1 924.9 917.6 909.9 903.1 930.7 925.6 918.3 910.7 903.8 931.4 926.2 919.0 911.4 904.6 932.0 926.8 919.7 912.1 905.3 932.6 927.4 920.3 912.8 906.0 933.2 928.0 920.9 913.5 906.7 933.8 928.6 921.6 914.1 907.4 934.4 929.2 922.2 914.7 908.1

296.4 303.0 312.8 323.3 333.1 296.4 303.0 312.8 323.3 333.1 296.4 303.0 312.8 323.3 333.1 296.2 303.0 312.8 323.3 333.2 296.2 303.0 312.8 323.3 333.2 296.2 303.0 312.8 323.3 333.2 296.2 303.0 312.8 323.3 333.2 296.2 303.0 312.8 323.3 333.2 296.2 303.0 312.8 323.3 333.2 296.2 303.0 312.8 323.3 333.2 296.2 303.1 312.8 323.3 333.2

914.2 908.7 901.1 893.0 885.5 914.8 909.4 901.8 893.7 886.3 915.5 910.1 902.5 894.5 887.1 916.3 910.8 903.3 895.2 887.9 917.0 911.4 904.0 896.0 888.6 917.7 912.1 904.6 896.7 889.4 918.3 912.7 905.3 897.4 890.2 918.9 913.4 906.0 898.1 890.9 919.5 914.0 906.7 898.8 891.7 920.1 914.6 907.3 899.5 892.4 920.7 915.3 908.0 900.2 893.1

Uncertainties u: u(T) = 0.1 K, u(P) = 0.007 MPa, u(ws) = 0.0001, and u(ρm) = 0.5 kg·m−3. 618



Article

Table 11. Measured Viscosities of Bitumen and Toluene Mixtures μm at Different Temperatures T and Pressures P; ws, Weight Fraction of Toluene in Mixturea ws = 0.05

a

ws = 0.1

ws = 0.2

ws = 0.3

ws = 0.4

ws = 0.5

ws = 0.6

P

T

μm

T

μm

T

μm

T

μm

T

μm

T

μm

T

μm

MPa

K

mPa·s

K

mPa·s

K

mPa·s

K

mPa·s

K

mPa·s

K

mPa·s

K

mPa·s

0.124 0.124 0.124 0.124 0.124 1.002 1.002 1.002 1.002 1.002 2.002 2.002 2.002 2.002 2.002 3.001 3.001 3.001 3.001 3.001 4.000 4.000 4.000 4.000 4.000 4.999 4.999 4.999 4.999 4.999 5.998 5.998 5.998 5.998 5.998 6.997 6.997 6.997 6.997 6.997 7.996 7.996 7.996 7.996 7.996 8.995 8.995 8.995 8.995 8.995 9.994 9.994 9.994 9.994 9.994

342.6 332.3 319.8 309.6 301.6 344.4 333.0 320.6 309.6 301.6 344.5 333.1 320.8 309.6 301.5 344.6 333.1 321.0 309.6 301.4 344.4 333.2 320.9 309.6 301.4 344.2 333.1 320.7 309.6 301.4 344.3 333.1 320.5 309.6 301.4 344.4 333.1 320.5 309.6 301.4 344.5 333.1 320.5 309.5 301.5 344.5 333.0 320.5 309.5 301.5 344.6 333.0 320.4 309.5 301.5

330.4 622.6 1371 3839 8865 308.9 613.7 1448 4349 10243 317.4 628.8 1478 4658 10980 326.1 646.2 1539 4802 11804 341.0 669.3 1630 5048 12204 358.0 696.8 1653 5162 12610 369.2 721.6 1831 5336 13163 381.0 752.3 1916 5316 13804 393.9 791.9 2026 5595 14352 407.5 828.3 2106 5971 15049 422.8 869.2 2199 6258 15628

342.0 331.0 321.0 310.2 302.4 344.3 332.4 321.3 310.5 302.6 344.5 332.8 321.5 310.6 302.5 344.6 333.0 321.5 310.4 302.6 344.7 332.9 321.6 310.6 302.6 344.6 332.8 321.6 310.4 302.8 344.5 332.9 321.6 310.5 302.8 344.3 333.0 321.6 310.6 302.8 344.2 333.2 321.6 310.6 302.8 344.3 333.4 321.6 310.7 302.8 344.5 333.4 321.6 310.4 302.8

121.3 216.6 410.9 881.5 1666 110.2 212.8 416.4 891.2 1698 112.3 213.1 422.1 913.3 1759 115.4 217.5 437.2 956.9 1810 118.1 226.4 448.0 981.3 1868 122.8 234.2 463.6 1034 1926 128.6 242.0 480.6 1070 1996 134.2 247.6 499.2 1104 2086 140.1 254.0 517.4 1156 2175 144.5 262.0 537.8 1197 2271 148.7 272.0 560.5 1288 2395

343.8 330.5 320.1 309.1 299.5 343.8 331.4 320.6 310.0 300.8 344.0 332.2 321.1 310.3 301.4 344.0 332.3 321.2 310.5 301.8 344.0 332.3 320.6 310.6 302.0 344.1 332.4 320.4 310.5 302.1 344.1 332.5 320.5 310.5 302.2 344.1 332.4 320.7 310.6 302.2 344.1 332.4 321.2 309.7 302.2 344.1 332.3 321.5 310.3 302.3 344.1 332.3 321.5 310.6 302.3

25.34 42.06 67.13 121.1 205.3 25.44 40.51 66.66 117.6 193.9 25.60 40.09 66.00 117.7 191.2 26.00 40.73 66.89 119.6 191.3 26.34 41.42 70.56 123.7 195.1 26.99 42.01 72.49 127.1 200.7 27.47 42.75 73.57 131.1 204.5 27.97 43.85 73.68 135.0 210.8 28.64 44.98 74.67 145.3 217.8 29.2 46.04 75.08 145.6 225 29.84 47.48 77.34 148.2 232.9

343.3 329.9 320.9 309.5 300.5 343.6 331.0 320.9 309.6 300.9 343.9 331.6 320.9 309.7 301.4 343.9 332.1 320.9 309.9 301.7 343.9 332.3 320.9 309.9 301.8 343.6 332.3 320.9 310.0 302.0 343.6 332.3 320.9 309.7 302.0 343.6 332.2 320.9 309.8 302.1 343.7 332.2 320.9 309.9 302.1 344.0 332.2 320.9 310.0 302.1 344.1 332.5 320.9 310.1 302.1

8.851 13.16 17.78 26.98 38.77 8.861 12.79 18.01 27.11 38.35 8.903 12.76 18.19 27.34 38.17 8.997 12.72 18.49 27.54 38.37 9.139 12.88 18.72 27.86 38.85 9.322 13.04 19.03 28.40 39.31 9.482 13.25 19.41 29.19 40.09 9.658 13.54 19.77 29.67 40.87 9.814 13.83 20.13 30.03 41.69 9.914 14.09 20.57 30.52 42.78 10.10 14.23 20.92 31.07 43.80

342.6 330.8 321.0 309.2 300.3 342.6 332.0 321.0 309.6 301.1 342.7 332.2 321.0 309.7 301.6 342.8 332.3 321.0 309.0 301.7 342.9 332.3 321.0 309.0 301.8 343.0 332.3 321.0 309.0 301.9 343.1 332.2 321.0 309.1 301.9 343.1 332.0 321.0 309.2 301.9 343.2 332.2 321.1 309.3 302.0 343.1 332.4 321.1 309.4 302.0 343.1 332.4 321.1 309.5 302.0

4.366 5.243 6.862 9.749 13.02 4.396 5.116 6.884 9.748 12.86 4.379 5.161 6.963 9.789 12.78 4.364 5.206 7.031 10.14 12.88 4.375 5.272 7.117 10.26 12.98 4.355 5.310 7.229 10.47 13.20 4.348 5.413 7.354 10.54 13.36 4.341 5.522 7.453 10.67 13.56 4.365 5.611 7.575 10.84 13.84 4.362 5.669 7.705 11.01 14.07 4.382 5.771 7.844 11.19 14.41

343.6 331.1 319.9 308.3 300.2 343.0 331.1 319.8 308.4 300.6 342.7 331.2 320.0 308.5 300.9 342.6 331.3 320.1 308.5 301.2 342.6 331.3 320.0 308.5 301.4 342.7 331.3 320.1 308.6 301.4 342.8 331.3 320.1 308.5 301.5 342.9 331.3 320.1 308.6 301.5 342.9 331.3 320.1 308.6 301.5 343.0 331.3 320.1 308.6 301.5 343.0 331.3 320.1 308.6 301.6

2.307 2.954 3.736 4.928 5.465 2.330 2.958 3.762 4.915 5.413 2.336 2.973 3.762 4.906 5.424 2.354 2.951 3.762 4.911 5.396 2.357 2.952 3.768 4.925 5.449 2.369 2.960 3.775 4.934 5.510 2.376 2.965 3.782 4.945 5.607 2.379 2.968 3.809 4.956 5.671 2.380 2.983 3.816 4.968 5.767 2.388 2.988 3.822 4.971 5.842 2.402 3.010 3.833 5.016 5.998

342.6 330.1 320.0 308.2 299.9 343.0 330.5 320.0 308.4 300.0 343.1 330.8 320.0 308.5 300.2 343.2 331.1 319.9 308.5 300.3 343.2 331.3 319.9 308.5 300.3 343.2 331.4 319.9 308.5 300.4 343.2 331.4 319.9 308.5 300.4 343.3 331.4 320.1 308.5 300.4 343.3 331.4 320.3 308.5 300.4 343.2 331.4 320.3 308.5 300.4 343.2 331.4 320.2 308.5 300.4

1.463 1.979 2.046 2.600 3.113 1.454 1.943 2.048 2.589 3.101 1.455 1.931 2.044 2.579 3.089 1.451 1.896 2.052 2.576 3.088 1.452 1.889 2.057 2.573 3.078 1.449 1.886 2.059 2.574 3.077 1.446 1.884 2.045 2.579 3.078 1.446 1.885 2.043 2.578 3.086 1.448 1.888 2.042 2.583 3.098 1.453 1.888 2.041 2.595 3.109 1.455 1.896 2.057 2.607 3.122

Uncertainties u: u(T) = 0.1 K, u(P) = 0.007 MPa, u(ws) = 0.0001, and u(μm) = 0.05 μm. 619



Article

Table 12. Measured Viscosities of Bitumen and Xylene Mixtures μm at Different Temperatures T and Pressures P; ws, Weight Fraction of Xylenes in Mixturea ws = 0.05

a

ws = 0.1

ws = 0.2

ws = 0.3

ws = 0.4

ws = 0.5

ws = 0.6

P

T

μm

T

μm

T

μm

T

μm

T

μm

T

μm

T

μm

MPa

K

mPa·s

K

mPa·s

K

mPa·s

K

mPa·s

K

mPa·s

K

mPa·s

K

mPa·s

0.124 0.124 0.124 0.124 0.124 1.002 1.002 1.002 1.002 1.002 2.002 2.002 2.002 2.002 2.002 3.001 3.001 3.001 3.001 3.001 4.000 4.000 4.000 4.000 4.000 4.999 4.999 4.999 4.999 4.999 5.998 5.998 5.998 5.998 5.998 6.997 6.997 6.997 6.997 6.997 7.996 7.996 7.996 7.996 7.996 8.995 8.995 8.995 8.995 8.995 9.994 9.994 9.994 9.994 9.994

301.1 309.4 319.6 332.2 344.8 301.1 309.2 319.3 332.3 344.6 301.1 308.7 319.4 332.4 344.5 301.1 309.0 319.4 332.5 344.5 301.2 308.8 319.5 332.6 344.5 301.2 308.3 319.6 332.7 344.5 301.3 308.0 319.9 332.7 344.6 301.4 308.3 320.0 332.8 344.6 301.5 308.9 320.0 332.8 344.6 301.6 309.0 320.1 332.8 344.6 301.6 309.1 320.1 332.8 344.6

12566 5065 2002 710.9 320.1 14215 5793 2290 733.7 336.8 15010 6497 2397 756.0 349.9 15770 6523 2486 778.1 362.1 15986 6987 2613 803.3 375.5 17115 7699 2640 836.3 388.3 17652 8330 2696 876.3 402.0 18182 8437 2781 911.9 418.4 18865 8418 2881 945.3 433.1 19495 8441 2957 997.7 451.6 20338 8791 3103 1043 468.1

302.0 309.4 321.1 333.2 343.9 302.2 309.7 321.4 333.2 344.4 302.2 309.9 321.5 333.3 344.5 302.1 309.9 321.5 333.3 344.6 302.2 310.0 321.5 333.2 344.6 302.2 310.0 321.5 333.2 344.6 302.2 310.1 321.5 333.2 344.6 302.2 310.1 321.5 333.2 344.6 302.2 310.2 321.5 333.2 344.6 302.2 310.2 321.5 333.2 344.6 302.2 310.2 321.5 333.2 344.6

2092 1119 470.1 226.2 128.2 2137 1126 473.3 232.4 129.3 2203 1145 486.1 233.6 132.8 2290 1176 499.4 240.2 134.5 2380 1214 514.9 249.1 138.8 2462 1257 533.4 257.3 143.7 2549 1309 552.4 266.1 147.5 2656 1362 573.1 275.6 153.5 2772 1421 594.3 286.6 159.3 2906 1483 617.9 296.5 166.7 3021 1549 642.5 309.5 172.8

301.9 308.1 320.5 332.2 344.0 302.2 309.4 320.5 332.2 343.9 302.3 309.8 320.6 332.3 343.9 302.4 310.3 320.6 332.3 343.9 302.5 310.4 320.7 332.3 343.9 302.4 310.4 320.7 332.3 343.9 302.5 310.3 320.8 332.3 343.9 302.5 310.2 320.7 332.3 343.9 302.5 310.1 320.7 332.3 343.9 302.5 310.0 320.7 332.3 343.9 302.5 309.9 320.8 332.3 343.9

225.7 145.3 76.62 44.01 27.56 228.4 137.0 76.69 44.24 27.54 233.7 137.5 77.53 44.78 27.86 238.0 137.7 78.89 45.51 28.28 245.6 141.3 80.01 46.38 28.74 254.3 145.5 81.73 47.30 29.29 263.4 151.0 83.52 48.42 29.78 272.2 157.1 85.40 49.35 30.49 281.3 163.5 87.30 50.39 31.05 292.7 170.9 89.54 51.62 31.77 304.5 178.1 91.62 52.99 32.48

301.4 309.4 318.9 330.9 343.7 301.8 309.5 319.9 332.3 343.7 301.9 309.5 320.1 332.4 343.7 301.9 309.5 320.4 332.4 343.8 302.0 309.5 320.5 332.5 343.8 302.0 309.4 320.5 332.5 343.8 302.1 309.4 320.6 332.5 343.8 302.1 309.4 320.6 332.6 343.8 302.0 309.4 320.6 332.6 343.9 302.1 309.4 320.7 332.6 343.9 302.1 309.3 320.7 332.6 343.9

41.83 29.87 21.33 14.51 10.08 41.33 30.26 20.77 13.99 10.14 42.02 30.71 20.89 14.13 10.23 42.57 31.09 20.99 14.31 10.39 42.76 31.61 21.26 14.47 10.54 43.89 32.24 21.57 14.71 10.69 45.67 32.88 21.91 14.96 10.91 45.78 33.47 22.32 15.19 11.09 46.98 34.22 22.71 15.47 11.28 47.85 34.89 23.19 15.79 11.47 49.10 35.86 23.66 16.01 11.71

300.3 308.9 318.6 331.1 343.8 301.3 309.1 320.0 331.8 343.4 301.3 309.2 320.3 332.1 343.4 301.4 309.3 320.4 332.1 343.5 301.5 309.3 320.5 332.1 343.4 301.5 309.3 320.5 332.1 342.7 301.5 309.3 320.5 332.0 342.7 301.5 309.3 320.6 332.0 342.8 301.5 309.3 320.6 332.0 342.9 301.5 309.3 320.6 332.1 343.0 301.5 309.3 320.6 332.0 343.1

16.19 11.90 8.786 6.153 4.374 15.74 11.93 8.504 6.059 4.477 15.84 12.02 8.494 6.066 4.500 15.97 12.15 8.573 6.163 4.552 16.17 12.31 8.649 6.245 4.612 16.41 12.49 8.813 6.360 4.767 16.66 12.67 8.958 6.479 4.850 16.97 12.90 9.096 6.565 4.903 17.27 13.14 9.270 6.664 4.981 17.59 13.48 9.430 6.792 5.068 17.90 13.74 9.638 6.941 5.161

301.1 309.0 319.6 331.1 342.7 301.2 309.1 319.7 331.1 342.7 301.3 309.1 319.8 331.2 342.7 301.2 309.2 319.8 330.8 342.7 301.3 309.2 319.9 330.7 342.7 301.2 309.3 319.9 330.9 342.7 301.2 309.3 319.9 331.1 342.7 301.3 309.3 319.9 331.1 342.7 301.3 309.4 319.9 331.2 342.7 301.3 309.4 319.9 331.2 342.8 301.2 309.4 319.9 331.2 342.8

6.312 5.007 4.471 3.473 2.751 6.325 5.006 4.450 3.529 2.761 6.399 5.064 4.454 3.504 2.777 6.481 5.112 4.450 3.545 2.764 6.582 5.187 4.476 3.582 2.752 6.650 5.270 4.484 3.522 2.761 6.759 5.350 4.497 3.513 2.773 6.845 5.446 4.502 3.513 2.764 6.971 5.504 4.521 3.525 2.774 7.085 5.616 4.545 3.531 2.790 7.234 5.711 4.562 3.548 2.796

300.0 307.1 318.5 331.1 341.9 300.1 308.1 319.2 331.1 342.2 300.2 308.3 319.4 331.1 342.4 300.3 308.3 319.5 331.1 342.6 300.3 308.5 319.6 331.0 342.7 300.3 308.5 319.6 331.0 342.8 300.4 308.5 319.7 331.0 342.8 300.4 308.5 319.7 331.0 342.8 300.4 308.6 319.7 331.0 342.8 300.5 308.6 319.7 331.0 342.8 300.5 308.6 319.7 331.0 342.8

3.373 2.885 2.423 1.800 1.515 3.364 2.910 2.362 1.800 1.505 3.386 2.899 2.368 1.814 1.514 3.385 2.910 2.369 1.812 1.504 3.375 3.002 2.353 1.812 1.504 3.396 3.004 2.362 1.812 1.508 3.399 2.997 2.373 1.813 1.508 3.405 3.007 2.372 1.824 1.512 3.424 3.017 2.385 1.828 1.514 3.445 3.024 2.390 1.838 1.517 3.456 3.040 2.402 1.843 1.523

Uncertainties u: u(T) = 0.1 K, u(P) = 0.007 MPa, u(ws) = 0.0001, and u(μm) = 0.05 μm. 620



Article

The measured viscosity data of aromatic solvents and bitumen mixtures were also evaluated with relationships developed for mixtures. These relationships were mostly developed for light and medium oils diluted with solvents. Centeno et al.40 summarized a total of 26 mixing rules and classified them according to the number and type of parameters as well as the information required for each relationship. In this study, we have evaluated two correlations, Lederer’s and power law models, as well as two prediction schemes, Arrhenius's and Shu's model. Only the two correlations lead to acceptable results in this study and have commonly been used for bitumen/solvent mixtures. The Arrhenius’ model41 or log type mixing rule is commonly used in the reservoir simulators to predict the viscosity of oilblended mixtures, and the equation is, μm = μsxs ·μB(1 − xs)

Figure 4. Density ρm of Athabasca bitumen/xylenes mixtures as a function of the weight fraction of xylenes ws at different temperatures and at a constant pressure of 10 MPa. Measured densities: ■, 296.6 K; ▲, 303.2 K; ○, 313.0 K; ⧫, 323.3 K; ×, 333.2 K. , predicted values.

(7)

or in the log form, ln μm = xs ln μs + (1 − xs)ln μB

(8)

where xs is the mole fraction of solvent and μs and μB are the viscosities of solvent and bitumen, respectively. The power law correlation is based on the Kendall model,42 in which the viscosity of the mixture is directly dependent on the concentration, μm = [xsμsn + (1 − xs)μBn ]1/ n

(9)

where the exponent n is the adjustable parameter in this correlation, xs is the mole fraction of solvent, and μs and μB are the viscosities of solvent and bitumen, respectively. Lederer43 proposed a modified version of the classic log-type viscosity mixing rule as, ⎛ ⎛ αvB ⎞ αvB ⎞ ln μm = ⎜1 − ⎟ln μs + ⎜ ⎟ln μB αvB + vs ⎠ ⎝ ⎝ αvB + vs ⎠

(10)

where vs and vB are the volume fractions of solvent and bitumen and α is an adjustable parameter having values between 0 and 1. Shu44 developed a method to calculate the constant α as,

Figure 5. Effect of pressure P on the density ρm of Athabasca bitumen/ toluene mixtures at different temperatures and a constant toluene weight fraction of 0.6. Measured densities: ■, 296.0 K; ▲, 302.9 K; ○, 313.1 K; ◆, 323.2 K; ×, 333.3 K. , predicted values.

α=

toluene is fixed at the highest value. The symbols are measured density data, and the predictions using eq 6 are shown by solid lines. The linear increase of the mixture density with pressure shown in the figure occurs at all measured temperatures and for both solvents. The results indicate that a large increase in the solvent weight fraction would not impact the linear behavior of the density data with pressure. The only remarkable point is that the predicted results at the highest temperature (i.e., 333 K) and the highest solvent weight fraction (i.e., 0.6 weight fractions) show slight deviations from the measured values. This may be due to a deviation from the assumption of no volume change on mixing at higher solvent weight fractions. The predicted values are less than the experimental data; therefore, it can be concluded that the volume change on mixing is negative for the mixture of solvent and bitumen. That is, the volume of the mixture is lower than the predicted value and thus, a positive deviation of the experimental densities from the predicted values follows. It can also be noted that, at higher temperatures, the assumption of ideal mixing for solvent and bitumen mixtures would not be appropriate.

17.04(ρB − ρs )0.5237 ρB3.2745 ρs1.6316 ln(μB /μs )

(11)

where ρs and ρB are the densities of solvent and bitumen, respectively. Shu44 showed that his correlation could determine the viscosity of heavy oils, bitumen, and petroleum fractions. The results of the two prediction schemes and of the two correlations with adjustable parameter for the viscosity of bitumen and toluene as well as bitumen and xylenes mixtures are presented in Figures 6 and 7, in which they are compared with experimental data. The viscosity of pure solvent was calculated using the correlation presented in Table 2, and the viscosity of raw bitumen at different temperature and pressure was calculated using eq 5 (coefficients listed in Table 8). The results indicate that the Lederer’s and power law models fit the data better than Shu's prediction scheme and Arrhenius's model. It is due to the parameters that are considered in Lederer’s and power law models. The viscosity results using Lederer’s and power law models lead to almost the same predictions. A comparison for the bitumen/toluene mixtures shows that AARD for Lederer’s model is 14.8 %, while this value is found to be 19.2 % for power law model. The adjustable parameters for these two models were obtained by regression of all data as 621



Article

Figure 6. Experimental mixture viscosities μexp versus calculated values μcal for bitumen and toluene mixtures using different mixing rules; correlated values: △, Lederer’s model; ○, power law model; predicted values: ×, Shu’s prediction scheme; ◆, Arrhenius's model.

Figure 8. Viscosity μm of Athabasca bitumen/toluene mixtures as a function of the weight fraction of toluene ws at different temperatures and at a constant pressure of 0.125 MPa. Measured viscosities: ■, 300.6 K; ▲, 309.2 K; ○, 320.4 K; ⧫, 330.8 K; ×, 342.9 K. Correlated values: , Lederer’s model; ---, power law model.

Figure 7. Experimental mixture viscosities μexp versus calculated values μcal for bitumen and xylenes mixtures using different mixing rules; correlated values: △, Lederer’s model; ○, power law model; predicted values: ×, Shu’s prediction scheme; ◆, Arrhenius's model.

Figure 9. Viscosity μm of Athabasca bitumen/xylenes mixtures as a function of the weight fraction of xylenes ws at different temperatures and at a constant pressure of 10 MPa. Measured viscosities: ■, 301.7 K; ▲, 309.4 K; ○, 320.5 K; ⧫, 332.2 K; ×, 343.7 K. Correlated values: , Lederer’s model; ---, power law model.

n = 0.0503 (exponent in power law model) and α = 0.2858 (coefficient in Lederer’s model). For bitumen/xylenes mixtures, the calculated results are in good agreement with the measured viscosity data; the AARD is 13.8 % for Lederer’s model and 17.1 % for the power law model. Their adjustable parameters are found to be n = 0.0350 and α = 0.3034. Due to the better representation of the experimental data with Lederer’s and power law models, the further discussion is restricted to these two models. In Figures 8 to 10, in which the experimental data are compared with the correlations, the results obtained by Lederer’s model are shown as solid lines, whereas the dashed lines represent the results of power law model. Figures 8 and 9 illustrate the effect of the increased solvent weight fraction on the mixture viscosity at different temperatures. The viscosity results are given in semilog plots. Figure 8 shows the results at the lowest pressure (0.125 MPa) for bitumen/toluene mixtures, and Figure 9 displays the data at the highest pressure (10 MPa) for bitumen/xylenes mixtures. As presented in these figures, the viscosity of the mixtures shows a curvilinear trend with respect to the solvent weight fraction at

two different pressures. The impact of temperature on the viscosity of the mixture is less pronounced at higher solvent weight fraction. The experimental data are well-correlated using Lederer’s and power law models. Even though no significant difference in the results of the two models is observed, at higher temperatures, Lederer’s model correlates the experimental data better than the power law model. To determine the effect of pressure along with the dilution of the mixture with solvent on viscosity, the viscosity data at different solvent weight fractions are plotted versus pressure in Figure 10. This figure shows the results at the lowest temperature for bitumen/toluene mixtures. The effect of pressure on the mixture viscosity shows a linear increase at each solvent weight fraction, and this effect is greater at the lower solvent weight fraction. The calculated values of the two models are slightly bigger than the experimental data at the lowest temperature (301.5 K). Figures 8 to 10 enable additionally to conclude that the correlated values obtained for the two models show larger 622



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Article

AUTHOR INFORMATION

Corresponding Author

*Address: Jalal Abedi, Associate Professor, 2500 University Dr., NW, Calgary, Alberta, T2N 1N4 Canada. E-mail: jabedi@ ucalgary.ca. Tel.: 403-220-5594. Funding

The support of Natural Sciences and Engineering Research Council of Canada (NSERC) and Schulich School of Engineering is acknowledged gratefully. Notes

The authors declare no competing financial interest.

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REFERENCES

(1) Jacobs, F. A.; Donnelly, J. K.; Stanislav, J.; Svrcek, W. Y. Viscosity of gas saturated bitumen. J. Can. Petrol. Technol. 1980, 19, 46−50. (2) Mehrotra, A. K.; Svrcek, W. Y. Measurement and correlation of viscosity, density and gas solubility for Marguerite Lake bitumen saturated with carbon dioxide. AOSTRA J. Res. 1984, 1, 51−62. (3) Mehrotra, A. K.; Svrcek, W. Y. Viscosity, density and gas solubility data for oil sand bitumens. Part I: Athabasca bitumen saturated with CO and C2H6. AOSTRA J. Res. 1985, 1, 263−268. (4) Mehrotra, A. K.; Svrcek, W. Y. Viscosity, density and gas solubility data for oil sand bitumens. Part II: Peace River bitumen saturated with N2, CO, CH4, CO2 and C2H6. AOSTRA J. Res. 1985, 1, 269−279. (5) Mehrotra, A. K.; Svrcek, W. Y. Viscosity, density and gas solubility data for oil sand bitumens. Part III: Wabasca bitumen saturated with N2, CO, CH4, CO2 and C2H6. AOSTRA J. Res. 1985, 2, 83−93. (6) Mehrotra, A. K.; Svrcek, W. Y. Properties of Cold Lake bitumen saturated with pure gases and gas mixtures. Can. J. Chem. Eng. 1988, 66, 656−665. (7) Svrcek, W. Y.; Mehrotra, A. K. Properties of Peace River Bitumen Saturated With Field Gas Mixtures. J. Can. Petrol. Technol. 1989, 28, 50−56. (8) Mehrotra, A. K.; Svrcek, W. Y. Viscositv of Compressed Athabasca Bitumen. Can. J. Chem. Eng. 1986, 64, 844−847. (9) Mehrotra, A. K.; Svrcek, W. Y. Viscosity of Compressed Cold Lake Bitumen. Can. J. Chem. Eng. 1987, 65, 672−675. (10) Badamchi-Zadeh, A.; Yarranton, H. W.; Svrcek, W. Y.; Maini, B. B. Phase behaviour and physical property measurement for VAPEX solvents: part I. propane and Athabasca bitumen. J. Can. Petrol. Technol. 2009, 48 (1), 54−61. (11) Badamchi-Zadeh, A.; Yarranton, H. W.; Maini, B. B.; Satyro, M. A. Phase Behaviour and Physical Property Measurements for VAPEX Solvents: Part II. Propane, Carbon Dioxide and Athabasca Bitumen. J. Can. Petrol. Technol. 2009, 48 (4), 57−65. (12) Khan, M. A. B.; Mehrotra, A. K.; Svrcek, W. Y. Viscosity Models For Gas-Free Athabasca Bitumen. J. Can. Petrol. Technol. 1984, 23, 47−53. (13) Svrcek, W. Y.; Mehrotra, A. K. Gas solubility, viscosity and density measurements for Athabasca bitumen. J. Can. Petrol. Technol. 1982, 21, 31−38. (14) Mehrotra, A. K.; Nighswander, J. A.; Kalogerakis, N. Data and Correlation for CO2−Peace River Bitumen Phase Behaviour at 22− 200 °C. AOSTRA J. Res. 1989, 5, 351−358. (15) Mehrotra, A. K. Development of mixing rules for predicting the viscosity of bitumen and its fractions blended with toluene. Can. J. Chem. Eng. 1990, 68, 839−848. (16) Lal, D. Solubility of Gases in Heavy Oils. MSc Thesis, The University of Alberta, Edmonton, Alberta, Canada, 1983. (17) Fu, C. T.; Puttagunta, V. R.; Vilcsak, G. Vapour Liquid Equilibrium Properties for Pseudo-Binary Mixtures of CO2−Athabasca Bitumen and N2−Athabasca Bitumen. AOSTRA J. Res. 1985, 2, 73−81. (18) Fu, C. T.; Puttagunta, V. R.; Vilcsak, G. Gas Solubility of Methane and Ethane in Cold Lake Bitumen at In Situ Conditions. J. Can. Petrol. Technol. 1988, 27, 79−85.

Figure 10. Effect of toluene concentration ws (in weight fraction) and pressure P on the viscosity μm of Athabasca bitumen/toluene mixtures at the lowest temperature (301.5 K). Measured viscosities: ■, ws = 0.05; ▲, ws = 0.1; ○, ws = 0.2; ◆, ws = 0.3; ×, ws = 0.4; ●, ws = 0.5; △, ws = 0.6. Correlated values: , Lederer’s model; ---, power law model.

deviations from the experimental data at higher temperature and at higher solvent weight fraction.

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CONCLUSION The density and viscosity of raw Athabasca bitumen and its mixtures with toluene and xylenes have been reported at the temperatures from room to 343 K and at the pressures up to 10 MPa on mixtures for different weight fractions of the solvents (0.05, 0.1, 0.2, 0.3, 0.4, 0.5, and 0.6). The density data for raw bitumen were fitted with a maximum deviation of ± 0.3 kg·m−3 using a correlation considering the impact of pressure and temperature. The viscosity data were fitted with two correlations (eqs 4 and 5) proposed by Mehrotra and Svrcek,8 and the AARDs are 2.1 % and 1.7 % for eqs 4 and 5, respectively. The viscosity of raw bitumen at different temperature and pressure was calculated using eq 5 for the calculation of the mixture viscosities. The data for the densities of bitumen/toluene and bitumen/ xylenes mixtures reveal linear trends with respect to the pressure and the solvent weight fractions at all temperatures. The data are quite well represented by {ρm = 1/(ws/ρm + wB/ρB)} over the entire temperature, pressure, and solvent weight fraction ranges. The AARDs are 0.04 % and 0.06 % for the bitumentoluene and bitumen/xylenes mixtures, respectively. The results indicate that the predicted density values at the highest temperature (i.e., 333 K) and the highest solvent weight fraction (toluene and/or xylenes) show slight deviations from the measured data. The viscosity of the mixtures shows a curvilinear trend with respect to the solvent weight fraction. The mixture viscosity data were evaluated with the two correlations, Lederer's and power law models, as well as two prediction schemes, Arrhenius's and Shu's model. The results indicate that the Lederer's and power law models represent the data better than Shu's and Arrhenius's models. A comparison shows that AARD's of Lederer’s model are 14.8 % for the bitumen/toluene and 13.8 % for the bitumen/ xylenes mixtures, while these values are found to be 19.2 % (bitumen/toluene) and 17.1 % (bitumen/xylenes) using the power law model. The comparison of experiment and correlation shows that the correlated values at the highest temperature and at the highest solvent weight fractions deviate from the experimental data. 623



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Density and Viscosity for Mixtures of Athabasca Bitumen and Aromatic

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