Advances in Engineering Fluid Mechanics: Multiphase Reactor and Polymerization System Hydrodynamics. Advances in Engineering Fluid Mechanics Series

761 Pages·1996·10.642 MB·English

by  Nicholas P. Cheremisinoff (Eds.)

CONTRIBUTORS TO THIS VOLUME
Mohammed Abid, Laboratoire de Genie Chimiqe URA CNRS 192, ENSIGC, 19 chemin
de la Loge, 31078 Toulouse Cedex, FRANCE
A. Afacan, Department of Chemical Engineering, University of Alberta, Edmonton,
Alberta, CANADA T6G 2G6
K. M. Irdriss Ali, Radiation and Polymer Chemistry Laboratory, Institute of Nuclear
Science and Technology, Bangladesh Atomic Energy Commission, P.O. Box 3787,
Bhaka, BANGLADESH
M. Azam Ali, Radiation and Polymer Chemistry Laboratory, Institute of Nuclear Science
and Technology, Bangladesh Atomic Energy Commission, P.O. Box 3787, Bhaka,
BANGLADESH
Neal R. Amundson, Department of Mathematics, University of Houston, Houston, Texas
77204, USA
Rutherford Aris, Department of Chemical Engineering and Materials Science, University
of Minnesota, 151 Amundson Hall, 421 Washington Avenue SE, Minneapolis,
Minnesota 55455-0132, USA
U. D. N. Bajpai, Polymer Research Laboratory, Department of Post-Graduate Studes and
Research in Chemistry, R.D. University, Jabalpur—482001, M.P., INDIA
Franco Berruti, Univeristy of Calgary, Calgary, Alberta, CANADA, 2TN 1N4
Joel Bertrand, Laboratoire de Genie Chiniqe URA CNRS 192, ENSIGC, 18 chemin de
la Loge, 31078 Toulouse Cedex, FRANCE
Neima Brauner, Department of Fluid Mechanics & Heat Transfer, School of Engineering,
Tel-Aviv University, Tel-Aviv, 69978, ISRAEL
Y. A. Buyevich, NASA Ames Research Center, Mail Stop 239-15, Moffett Field,
California 94035-1000 U.S.A.
J. B. L. M. Campos, Department of Chemical Engineering, University of Oporto, Oporto,
PORTUGAL
Jamal Chaouki, Ecole Polytechnique de Montreal, Montreal, Quebec, CANADA, H3C
3A7
R. P. Chhabra, Department of Chemical Engineering, Indian Institute of Technology,
Kanpur, INDIA, 208016
K. S. Chian, School of Applied Science, Nanyang Technological University, Nanyand
Avenue, SINGAPORE 2263
M. Chidambaram, Department of Chemical Engineering, Indian Institute of Technology,
Madras 600 036 INDIA
L. Choplin, GEMICO-ENSIC, 1 rue Grandville, B. P. 451, Nancy, 54001, FRANCE
Supid Kumar Das, Chemical Engineering Department, Calcutta University, 92 A.P.C.
Road, Calcutta—700 009, INDIA
E. B. de la Fuente, Departamento de Alimentos y Biotechnologia, Facultad de Quimica—
UNAM Mexico, D.F. 04510, MEXICO
U. K. Ghosh, Department of Chemical Engineering, Banaras Hindu University, Varanasi,
INDIA 221005
R. O. E. Greiner, Siemens AG, Corporate Research and Technology, 91050 Erlangen,
GERMANY
J. R. F. Guedes de Carvalho, Department of Chemical Engineering, University of Oporto,
Oporto, PORTUGAL
V. K. Gupta, Research Centre, Indian Petrochemicals Corporation Ltd., Vadodara—391
346, INDIA
Prabir Kumar Haider, Department of Power Plant Engineering, Jadavpur University,
Calcutta—700091, INDIA
Min Hyeon Han, R&D Center, Kumho & Co., Inc., Sochondong, Kwangsanku, Kwangju
506-040, KOREA
M. A. Kahn, Radiation and Polymer Chemistry Laboratory, Institute of Nuclear Science
and Technology, Bangladesh Atomic Energy Commission, P.O. Box 3787, Bhaka,
BANGLADESH
S. K. Kapbasov, Department of Mathematical Physics, Urals State University, 620083
Yekaterinburg, RUSSIA
J. Kaschta, University of Erlangen-Nurnberg, Institute for Material Science, Chair for
Polymers, Martensstr. 7, 91058 Erlangen, GERMANY
Y. Kawase, Department of Applied Chemistry, Faculty of Engineering, Toyo University,
Kujirai, Kawagoe-Shil Saitama, 350 JAPAN
Jin Kuk Kim, Department of Polymer Science & Engineering, Gyeongsang National
University, 900 Kajwa-Dong Chinju, Gyeongnam 660-701, Seoul, KOREA
Suzanne M. Kresta, University of Alberta, Edmonton, Alberta, CANADA, T6G 2G6
J. K. Kun, Department of Polymer Science & Engineering, Gyeongsang National
University, Chinju 660 701 KOREA
D. Moalem Maron, Department of Fluid Mechanics & Heat Transfer, School of
Engineering, Tel-Aviv University, Tel-Aviv, 69978, ISRAEL
J. H. Masliyah, Department of Chemical Engineering, University of Alberta, Edmonton,
Alberta, CANADA, T6G 2G6
H. A. Nasr-El-Din, Laboratory Research & Development, Saudi Aramco, P.O. Box 62,
Dhahran 31311, SAUDI ARABIA
V. Nassehi, Chemical Engineering Department, Loughborough University of Technology,
Loughborough, Leicester, LEll 3TU U.K.
Nivedita, Polymer Research Laboratory, Department of Post-Graduate Studies and
Research in Chemistry, R.D. University, Jabalpur, 482001 M.P., INDIA
Hasan Orbey, Center for Molecular and Engineering Thermodynamics, Department of
Chemical Engineering, University of Delaware, Newark, DE 19716, USA
Gregory S. Patience, E.I. du Pont de Nemours, Wilmington, DE 19880-0262, USA
M. Ravindranathan, Research Centre, Indian Petrochemicals Corporation Ltd., Petro
chemicals, Vadodara-391-346, INDIA
Shashikant Ravindranathan, Research Centre, Indian Petrochemicals Corporation Ltd.,
Petrochemicals, Vadodara-391-346, INDIA
Stanley I. Sandler, Center for Molecular and Engineering Thermodynamics, Department
of Chemical Engineering, University of Delaware, Newark, DE 19716, USA
C. W. Stewart, Pacific Northwest Laboratory, Richland, WA 99352, USA
P. A. Tanguy, Department of Genie Chimique, Ecole Polythecnique de Montreal, P.O.
Box 6079 Station Centre Ville, Montreal, H3C 3A7, CANADA
Lorenzo Tassi, University of Modena, Department of Chemistry, 41100 Modena, ITALY
K. C. Taylor, Petroleum Recovery Institute 100, 3512 33rd Street NW, Calgary, Alberta,
CANADA T2L 2A6
A. Tecante, Departamento de Alimentos y Biotecnologfa, Facultad de Quimica—UNAM
Mexico, D.F., 04510, MEXICO
J. A. S. Teixeira, Escola Superior Agraria, Instituto Politecnico de Braganca, Braganca,
PORTUGAL
Keio Toi, Department of Chemistry, Faculty of Science, Tokyo Metropolitan University,
Minamiosawa, Hachioji, Tokyo 192-03, JAPAN
C. P. Tsonis, Chemistry Department, King Fahd University of Petroleum and Minerals,
Dhahran 31261, SAUDI ARABIA
S. N. Upadhyay, Department of Chemical Engineering, Banaras, Hindu University,
Varanasil, INDIA 221005
E. M. Valles, Planta Piloto de Ingenieria Quimica, UNS-CONICET, 8000 Bahia Blanca,
ARGENTINA
M. A. Viler, Planta Piloto de Ingenieria Quimica, UNS-CONICET, 8000 Bahia Blanca,
ARGENTINA
Catherine Xuereb, Laboratoire de Genie Chiniqe USA CHRS 192, ENSIGC, 18 chemin
de la Loge, 31078 Toulouse Cedex, FRANCE
M. Yue, School of Applied Science, Nanyang Technological University, Nanyang Avenue,
SINGAPORE 2263
ABOUT THE EDITOR
Nicholas P. Cheremisinoff is a consultant to private industry, government, and academia.
He is an internationally recognized expert in multiphase flow system designs and polymer
science. He has nearly 20 years of industry and applied research experience in
petrochemicals manufacturing, synthetic fuels, elastomers, and emerging technologies for
environmental restoration programs in the U.S., the Soviet Union, and the Far East.
Dr. Cheremisinoff is with K&M Engineering and Consulting Corporation in Washington,
D.C., is Donetsk Resident Director in Kiev and Donetsk, is Resident Director in the
Ukraine, and is affiliated with the Donetsk University. He is the author, co-author and
editor of more than 100 engineering textbooks, numerous patents and research articles.
He received his B.S., M.S., and Ph.D. degrees in chemical engineering from Clarkson
College of Technology.
PREFACE
This volume of the Advances in Engineering Fluid Mechanics Series covers topics in
hydrodynamics related to polymerization of elastomers and plastics. Emphasis is given
to advanced concepts in multiphase reactor systems often used in the manufacturing of
these products. This volume is comprised of 30 chapters that address key subject areas
such as multiphase mixing concepts, multicomponent reactors and the hydrodynamics
associated with their operation, and slurry flow behavior associated with non-Newtonian
flows. The intent of this book is to provide new concepts and an understanding of
rheologically complex systems that undergo both phase changes and are subject to high
transport exchanges. The series intends to explore additional areas including the dynamics
of polymer processing operations.
As in preceding volumes in this series. Multiphase Reactor and Polymerization System
Hydrodynamics is comprised of contributions by recognized researchers and industry
members. The efforts of these authors should be commended. A special thanks is extended
to Gulf Publishing Company for its fine production of this series.
Nicholas P. Cheremisinoff, Ph.D.
Editor
CHAPTER 1
THE VISCOSITY OF LIQUID HYDROCARBONS
AND THEIR MIXTURES
Stanley I. Sandler and Hasan Orbey
Center for Molecular and Engineering Thermodynamics
Department of Chemical Engineering
University of Delaware
Newark, DE 19716
CONTENTS
SCOPE, 1
TERMS AND DEFINITIONS, 2
EXPERIMENTAL BEHAVIOR, 2
CORRELATIONS FOR THE VISCOSITY OF PURE AND MIXED
HYDROCARBONS, 7
VISCOSITY-TEMPERATURE RELATIONS AT LOW PRESSURES
FOR PURE LIQUID, 7
Empirical Andrade-Type Relations, 7
Corresponding States Methods for Pure Hydrocarbons, 9
Other Prediction and Correlation Methods for the Viscosity of Pure
Hydrocarbon Liquids, 11
VISCOSITY OF LIQUID HYDROCARBON MIXTURES AT AMBIENT
PRESSURE, 13
Extension of Andrade-Type Correlations to Mixtures, 14
Extension of Corresponding States Methods for Viscosity of Mixtures, 15
Extension of the Theoretically Based Methods to Mixtures, 15
Viscosity Models for Undefined Mixtures, 16
VISCOSITY OF LIQUID HYDROCARBONS AND THEIR MIXTURES
AS A FUNCTION OF PRESSURE, 17
Models that Correct Ambient Pressure Viscosity for Pressure, 18
Models that Incorporate Pressure Implicitly, 18
CONCLUSIONS AND RECOMMENDATIONS, 19
NOTATION, 20
REFERENCES, 21
1
2 Advances in Engineering Fluid Mechanics
SCOPE
This chapter deals with correlation and prediction methods for the viscosity of
liquid hydrocarbons and their mixtures. In particular, the change of viscosity of such
fluids with temperature, pressure, and composition is considered. We begin with a
brief introduction of terms and definitions, and then discuss the experimentally
observed behavior of the viscosity of liquid hydrocarbons as a function of tem
perature, pressure, and composition. Next, the main types of viscosity models
applicable to liquid hydrocarbons and their mixtures are reviewed. We also indicate
the accuracy of several recent viscosity correlation and prediction methods that
represent the general types of models in current use. The emphasis in this review
is on the recent viscosity models, especially those after 1987, as reviews exist of
the earlier methods [1,2], and because the recent methods are usually more accurate.
TERMS AND DEFINITIONS
When a Newtonian liquid, such as a hydrocarbon mixture, is subjected to a
shearing stress, a velocity gradient develops within the fluid. Viscosity (or dynamic
viscosity) is defined as the shear stress per unit area at any point within the fluid
divided by the velocity gradient at that point. Consequently, the viscosity is a
dynamic property; nevertheless, for Newtonian liquids it is a state property, that
is, it depends only on state properties such as temperature and pressure or density.
The dimensions of viscosity are force x time/length^ or equivalently mass/length x
time. Occasionally kinematic viscosity, which is the ratio of dynamic viscosity to
fluid density, is used instead of dynamic viscosity. The dimensions of kinematic
viscosity are lengths/time.
In the SI system the units of viscosity are N-s/m^ or Pa»s, and the units of
kinematic viscosity are m^/s. In scientific and engineering work, the unit Poise
(abbreviated P) is also used, with 1 Poise equal to 0.1 N-s/m^. Similarly for
kinematic viscosity the unit Stoke (St) is used with 1 Stoke equal to 10"^ m^/s.
EXPERIMENTAL BEHAVIOR
The general viscosity behavior of hydrocarbon liquids, with respect to temperature,
pressure and composition is reasonably well documented [3-6]. Temperature has
the greatest effect on viscosity, with the viscosity being extremely high at the
melting point of a fluid and decreasing by orders of magnitude as temperature
increases. At low pressures (from the saturation pressure to a few bars above
atmospheric), the viscosity is a function of temperature and essentially independent
of pressure. The viscosity-temperature behavior of several liquid alkanes is shown
in Figure 1. Other hydrocarbon fluids and their mixtures follow a similar trend. In
general, the viscosity of a hydrocarbon decreases monotonically as the temperature
increases, and the logarithm of viscosity decreases almost linearly with increasing
temperature. At temperatures near and above the normal boiling point this linearity
disappears for most liquids.
At a given temperature, the viscosity of hydrocarbons generally increases with
their molecular weight, though the effect of molecular structure is also significant
The Viscosity of Liquid Hydrocarbons and Their Mixtures 3
' 1 —^—r— ^—r —'—r T ^ 1 ^ \ ^ 1
1.5 •
C12 1
•
C10
D
• • C8 J
100
C7 J
O
D
9 • C6 1
8 •
I
7 - D -1
CL
E - • J
6
• D
(o/) 5 A -]
o
(f) D
*> Q)^
O
o
o
D
O
O
I
J \ 1 I I I I \ L
280 300 320 340 360 380 400 420 440
temperature, K
Figure 1. Viscosity vs. tennperature at atnnospheric pressure for various
alkane hydrocarbons. Data are from Knapstad et al. [40].
among the hydrocarbons with similar molecular weights. In Figure 2, the viscosities
of several C^ hydrocarbons are shown as a function of temperature. There we see
that at comparable temperatures, the cyclic molecules cyclohexane (melting tem
perature T^ = 278.7°K) and benzene (T^ = 279.6°K) have much higher viscosities,
especially at lower temperatures due to their higher melting temperatures than
n-hexane (T^ = 177.8°K). However, since 2-methyl pentane (T^ = 119.5°K) has a
lower viscosity than normal hexane, and 2,2-dimethyl butane (T^ = 173.3°K) has
a higher viscosity, the only general statement that can be made is that the effect of
chain branching on viscosity is important, but smaller than the effect of either
melting temperature or ring formation. Note also that while there is a large variation
in the melting temperatures of the noncyclic alkanes (in addition to the melting
points given in Figure 2, we have that 3-methyl pentane T^ = 155.0°K, 2,3-dimethyl
butane T^ = 144.6°K, and 1-hexene T^ = 133.3°K), all the €5 hydrocarbons have
normal boiling points within 20°K of each other. Consequently, as liquids have very
4 Advances in Engineering Fluid Med lanics
1.3 r
—1— 1 "1 1 1— -T 1 " • ' — 1 — 1 — j— ""' 1 1 \ 1 1 1 1 1
•
1.2 H
-]
1.1
•
1.0 • hexane J
• 2 methyl pentane 4
0) 0.9 • 2 2 dimethyl butane H
1 •
cd ^cyctohexane ]
E 0.8 - • • benzene 1
• •
'S5 0.7 • H
o • • J
o 0.6 • • H
'>CO T • J
0.5 h • T
• • •
L • •
0.4 •
r ^ • • J
0.3 A t «t T J
t f . • J
0.2
1 L.
-J 1 1 L. --J 1 1 1 1 i 1 1 i
270 280 290 300 310 320 330 340 350 360
Temperature, K
Figure 2. Effect of molecular structure on the viscosity of Cg hydrocarbons.
Data are from the compilation of Viswanath and Natarajan [1].
high viscosities near their melting points, this results in marked differences in
viscosities of the components over the temperature range of 120''K to 290°K, but more
similar behavior at higher temperatures. These statements concerning the effects of
melting point, branching, and ring formation are also true for other hydrocarbons.
The effect of large changes in pressure at constant temperature on the viscosity
of various hydrocarbons is shown in Figure 3. There we see that the logarithm of
the viscosity of liquid hydrocarbons and hydrocarbon mixtures increases almost
linearly with increasing pressure. Alternatively, viscosity can be considered to be
a function of density rather than pressure, and this is used in several of the models
discussed later. The kinematic viscosity shows similar trends with respect to these
variables mentioned above, however its variation with temperature is significantly
more linear than dynamic viscosity so that the former is somewhat easier to correlate
than the latter. Consequently, some correlations have been developed exclusively
for the kinematic viscosity, as will be discussed later.
The Viscosity of Liquid Hydrocarbons and Their Mixtures 5
\ 1 1 1 \ p I
•
D
2
a
• D
D
D
D
a
Q. ft D
O
r • • H
•
CooO ^ • • • • • o o o \
to • o o o • 1
'> o •
o •
• •
•
• OA C12
• C10 J
1.5 • D
• C8
C7
O
C6
•
10-1 -
1 ' 1 1 1 1 1 L. 1 . 1
100 200 300 400 500
pressure, bar
Figure 3. Viscosity vs. pressure at 373°K for various alkane hydrocarbons.
Data are fronn Ducoulombier et al. [4] and from Gouel [5].
There are some more specific observations that can be made about liquid vis
cosities. For example, except for the first members of a homologous series, the
viscosity of most pure liquids at their normal boiling point is, to within ±30%:
^(Tb) - 0.29 cP (1)
where T^ is the normal boiling point [7]. Also, from transition state theory [8] the
temperature dependence of the viscosity is:
lnii(T) = A + B ^- (2)
Further, the following dependence of the viscosity of oils on pressure [9] has been
suggested
In |i(T) = a + bP (3)