Upload
others
View
2
Download
0
Embed Size (px)
Citation preview
Deposition of Particles from Non-aqueous Suspensions in an Impinging Jet
Patricia L Stelmack1, Jacob H Masliyah1, Jan Czarnecki2 and Murray R Gray*1
1. Department of Chemical and Materials Engineering, University of Alberta,
Edmonton, AB T6G 2G6
2. Syncrude Canada Ltd. 9421-17 Ave., Edmonton, AB T6N 1H4
March, 1999
* Author for correspondence:
Murray R Gray Department of Chemical and Materials Engineering University of Alberta Edmonton, Alberta. T6G 2G6 FAX: (403) 492-7965 E-mail: [email protected]
1
Abstract
The purpose of this study was to define the mechanism of particle deposition on collectors in
non-aqueous media, in order to understand filtration of fine particles in packed-bed reactors for
hydrotreating of petroleum fractions. A model suspension of either carbon black or hydrophobic
kaolin particles in kerosene was used in the well-defined flow field provided by an impinging jet.
The coverage of a horizontal glass collector surface was determined with time by microscopy.
Deposition of particles was measured in pure kerosene, and with the addition of phenol or
quinoline to simulate the polar compounds found in the feed streams to hydrotreating reactors.
Deposition increased when small amounts of phenol or quinoline were present, and kaolin
particles deposited much more slowly than carbon black, but the properties of the medium were
unchanged. The pattern and rate of deposition showed that positive particle-particle interactions
favored the formation of clusters of particles on the collector surface.
Keywords:
Particle deposition, Hydrotreating, particle filtration, pressure drop
2
Introduction
Fine particles are commonly found in refinery process streams due corrosion of piping,
tank walls and vessels, entrainment from processes such as delayed coking, or from the
production of the oil as in the case of heavy oils and oilsands. Although desalting, distillation
and filtration remove most of the particles, low concentrations can persist in the feed streams to
packed-bed catalytic reactors such as hydrotreaters. Although these particles are typically
smaller than 20 µm in diameter, and hence smaller than the diameter of the flow channels
between the catalyst pellets, they are filtered from the liquid by deposition on the surface of the
catalyst pellets. This process is analogous to deep-bed filtration. Even if the efficiency of
removal is low, a few parts per million of particles can accumulate significantly during months
of operation. This accumulation can increase the pressure drop across the reactor catalyst beds to
the point where the reactor must be shut down, even though the catalyst activity is still
satisfactory (Chan et al. – ref; ??? Koyama et al., 1995). In order to help minimize this problem
in hydrotreater operation, a better understanding of the mechanisms involved in particle
deposition in nonaqueous media is essential.
The mechanisms of particle deposition have been studied extensively for aqueous media
(Elimelech and O’Melia 1990, Vatistas 1991), but not in non-aqueous media. Particle deposition
requires the arrival of a particle to the surface; attachment of a particle to the surface. Deposition
is determined by the balance between deposition and resuspension of a particle in the liquid
medium (Vatistas 1991). These processes are regulated by several factors, including the overall
kinetics of deposition onto a surface, the fluid dynamics of the flowing suspension, the surface
characteristics of the particles, and the physical properties of the suspension. The overall kinetics
3
are determined by the rates of arrival, attachment, and resuspension. The arrival of particles to a
surface is governed by the size of the particles. Submicron particles are transported to the surface
as a result of convection and diffusion, while larger particles are transported to the surface as a
result of physical forces arising from gravity and fluid drag (Elimelech and O’Melia 1990).
The attachment of particles to a surface is regulated by van der Waals forces and by double layer
repulsion (Chowdiah et al. 1981, Elimelech and O’Melia 1990, van der Hoeven and Lyklema
1992, Visser 1995). The van der Waals interactions are determined by the properties of both the
particles and the surface, rather than the properties of the suspending medium. Thus, van der
Waals forces are important in both aqueous and non-aqueous systems. Any repulsion between a
particle and a surface is due to the presence of an electrostatic double layer repulsion. This
double layer repulsion forms when materials suspended in liquid acquire a charge which attracts
ions of the opposite charge, thereby forming a double layer. This phenomenon is well
documented for aqueous systems (Visser 1995), but van der Hoeven and Lyklema (1992) have
indicated that it is also a factor in non-aqueous systems. They concluded that in non-aqueous
systems, double layer repulsion is regulated by the dielectric constant, the ionic strength, the
surface potential, the Hamaker constant, and the particle size. They noted that these are the same
parameters that regulate double layer repulsion in aqueous media, but that the important
condition that must be met if a double layer repulsion is to form is that the ionic strength within
the medium must be sufficiently high. When the dielectric constant and the conductivity are low,
as in non-polar organic solvents, then the double layers are quite thick giving an extended range
for electrostatic interactions. The dielectric constant of a liquid hydrocarbon medium is less than
5, while that of water is approximately 80. Similarly, the electrical conductivity of a liquid
4
hydrocarbon medium is several orders of magnitude lower than that of water (Chowdiah et al.
1981).
A unique characteristic of the behavior of fine particles in packed-bed catalytic reactors
is that the medium is a mixture of many different compounds, and this compositions can change
with position in the reactor due the action of the catalyst. In the case of hydrotreating, the
catalytic reactions convert compounds that contain sulfur and nitrogen, and to a lesser extent
oxygen, thereby liberating hydrogen sulfide, ammonia and water. These hydrogenation products
vaporize into the gas phase. As the liquid flows down through the catalyst bed, it gradually
changes from a solution of polar heteroatomic compounds in a hydrocarbon medium to a
solution of hydrocarbons alone.
One method for studying the step toward an understanding of the mechanisms that
regulate particle deposition in such non-aqueous media is to study a model system. Hydrotreaters
typically operate at temperatures over 300 °C and pressures over 3 MPa with two-phase flow of
liquid and vapor. The presence of a flowing gas gives much more complex time-varying
hydrodynamics than in single-phase flow. Both the catalyst and the fine particles will remain
liquid wet, therefore, the interactions between particles and the collector surface in a liquid phase
will control the deposition process. The objective of this study was to study the effect of
changing liquid-phase composition on the on particle deposition under controlled conditions,
using a model geometry and a model suspension. A jet of liquid impinging on a glass microscope
slide provided a well defined flow-field, and allowed direct observation of particle deposition.
The model suspension was fine particles suspended in kerosene, following van der Hoeven and
Lyklema (1992). The particles used were carbon black and kaolin particles, in order to examine
the role of the surface chemistry of the particles. Phenol and quinoline were added to the
5
kerosene to evaluate the differences in deposition caused by more polar compounds that are
typical of hydrotreating. The dielectric constant and conductivity of each kerosene solution was
measured to monitor changes to the physical properties that could alter particle behavior.
Materials and Methods
Chemicals
Two types of particles were used in this study. Carbon black particles with an average
diameter of 0.2 µm were selected as a model for hydrophobic carbonaceous solids, such as coke.
Much of the fine particulate matter in bitumen consists of clay minerals with a surface layer of
adsorbed asphaltene and humic components (Chung et al., 1998). This material was simulated by
coating 0.5 µm particles of kaolin with asphaltenes, following the method of Yan and Masliyah
(1996). A 1 g sample of the asphaltene fraction of bitumen was dissolved in 500 mL of 50%
heptane/50% toluene mixture, then 2.5 g of kaolin particles were added and the resulting mixture
was stirred at 200 rpm for 24 hours. The particles were recovered by filtering the mixture
through a 0.22 µm membrane filter and drying under vacuum. Kerosene (Aldrich Chemical
Company, Inc., Milwaukee, Wisconsin), phenol (American Chemicals Ltd., Montreal, Quebec)
and quinoline (Aldrich Chemical Company, Inc., Milwaukee, Wisconsin) were used as received.
The dielectric constants of solutions consisting of pure kerosene, kerosene and phenol,
and kerosene and quinoline were determined by Dr. Wayne Tinga, Department of Electrical and
Computer Engineering, University of Alberta. The dielectric constants were measured by a
single frequency microwave at 915 MHz and 20oC (Tian et al. 1992; Tinga 1992).
The conductivity of each solution was determined by using a probe (Catalog #13-639-
123, Fisher Scientific Limited, Nepean, Ontario) connected to an electrometer (Model #617,
6
Keithley Instruments, Inc., Cleveland, Ohio). The conductivity, x, was calculated from the
measured resistance, R, as follows:
Rkx /= (1)
where k is the cell constant determined from the measured resistance of a KCl solution with a
specific conductivity, x, of 0.1 S/cm.
Impinging Jet Apparatus
The impinging jet consisted of a capillary tube encased in a larger glass cell. The
diameter of the capillary tube was 2 mm, and the distance between the top of the capillary tube
and the top of the cell was 1.7 mm. The glass cell was 50 mm high, and had an inner diameter of
20 mm. A glass microscope slide was placed on top of the cell in such a way that there were no
air pockets or bubbles within the cell.
A beaker containing the particles suspended in kerosene was placed in an ultrasonic bath
(Model #1210R-MTH, Branson Ultrasonics Corporation, Danbury, Connecticut) in order to
disperse the particles. The suspension flowed from the beaker through the capillary tube into the
glass cell, and jetted towards the surface of the glass microscope slide. No chemical dispersant
was used to stabilize the suspension because the bubbles resulting from the presence of a
dispersant could not be eliminated. The liquid then exited the glass cell and flowed through a
glass tube into another beaker, from where it was pumped back into the beaker in the ultrasonic
bath. The glass exit tube, which had a diameter of 0.8 mm, controlled the velocity of the flowing
suspension through the impinging jet. The liquid flow rate was measured by a rotameter (Model
#FM-1050 Tube E627, Matheson Instruments, Montgomeryville, Pennsylvania). All experiments
were carried out at room temperature, 22±2oC. The glass cell was placed under a microscope
(Leitz Laborlux 12 ME S, Leica, Wetzlar, Germany) so that the stagnation point of the
7
impinging jet was in the center of the viewing area. A video camera (Model #VCB-3514, Sanyo
Electric Co. Ltd., Osaka, Japan) was mounted on top of the 20 x microscope objective, and
images of the particles depositing on the glass slide surface were relayed to a VCR (Model #EV-
S5000, Sony Corporation, Park Ridge, New Jersey). The images were recorded over a period of
2 hours.
Data Analysis
A computer software package, Optimas (Optimas Corporation, Bothell, Washington),
was used to analyze the deposition rates of the particles. Using this software, images of the
particles on the microscope slide were saved at times from 3 to 120 min. The images were then
analyzed to determine the percentage of the area that was covered by particles at each time. The
total viewing area of the slide was 8 mm2.
Results
Deposition of Carbon Black Particles from an Impinging Jet
All experiments were conducted at a Reynolds number of 75 (flow rate 7.5 mL/min,
density 800 kg/m3, viscosity 0.0215 kg/m·s). The deposition of carbon black particles suspended
in kerosene at concentrations ranging from 5 to 20 mg/L is plotted as a function of time in Figure
1. At all carbon black concentrations, 2-dimensional clusters of particles formed until
approximately 50% of the glass microscope slide was covered with particles. An adjustment of
the microscope objective revealed that additional particles then began to adhere to the underside
of existing particles, giving 3-dimensional clusters. Once this particle-on-particle deposition had
begun, the fraction of the area covered by particles was no longer proportional to the number or
mass of particles deposited on the surface of the collector. The data obtained using a carbon
black concentration of 10 mg/L were the most reproducible, therefore, this concentration was
8
used for all subsequent experiments. The data for the first 10 min of the experiments, i.e. at low
extents of deposition, at concentrations of 5, 10, and 20 mg/L are shown in Figure 2. The error
bars show the standard deviation for five repeated experiments.
Photographs of carbon black particles that deposited from a 10 mg/L suspension are
shown in Figure 3. Photograph (a), taken at 5 minutes, shows a few particles randomly
distributed on the surface. Photograph (b) was taken at 10 minutes, which corresponds to the
time when random deposition ceased. The 2-dimenstional clusters began to expand, as shown in
photograph (c), taken at 30 minutes, and these clusters started to form bridges between one
another in photograph (d), at 60 minutes. Once the bridging stage was complete, at
approximately 70 minutes, the particle-on-particle deposition began and the clusters became 3-
dimensional.
Deposition with Phenol and Quinoline
The data of Figure 4 show the deposition rate of carbon black particles at a concentration
of 10 mg/L when phenol was added to the kerosene at concentrations of 0.1, 5, 10, and 20 g/L.
This range of concentration of 0-4200 ppm oxygen content spans the range that would occur in
distillates from Athabasca bitumen. These curves were compared to the curve depicting carbon
black deposition when no phenol was present. This figure shows that as the amount of phenol
added to the kerosene increased to a concentration of 10 g/L, carbon black deposition on the
glass slide also increased. At a concentration of 20 g/L, the phenol was insoluble in kerosene,
and pockets of phenol were clearly visible on the surface of the glass slide. At lower phenol
concentrations, the particles were easily dispersed in the ultrasonic bath, since single particles
were observed coming out of the impinging jet and onto the glass microscope slide. However, 2-
dimensional flakes were observed in the collection beaker, indicating that aggregation occurred
9
after the particles exited the glass cell. An adjustment of the microscope objective revealed that
particles did not adhere to the underside of existing particles when phenol was present at
concentrations of 10 g/L and lower, even after 60% of the glass slide was covered with the first
layer of particles.
In the presence of phenol at a concentration of 10 g/L, the particles deposited on the
surface randomly during the first 5 min of the experiments. This observation indicated that the
random deposition period was shorter in the presence of phenol than in the absence of phenol.
The 2-dimensional clusters that formed were larger than those in the absence of phenol. After 60
minutes, the formation of clusters slowed, and very few particles were deposited, either adjacent
to existing particles or on the underside of existing particles.
The data of Figure 5 show the deposition rate of carbon black particles at a concentration
of 10 mg/L on the glass slide at concentrations of 0, 7 and 15 g/L of quinoline, corresponding to
0-2000 ppm of nitrogen. The deposition rate of carbon black particles also increased as the
amount of quinoline was increased. In the presence of quinoline, spherical aggregates consisting
of approximately 10 carbon particles were observed exiting the impinging jet onto the glass
microscope slide. This observation suggested that the particles were not fully dispersed in the
ultrasonic bath in the presence of quinoline, and this formation of spherical aggregates meant
that a 3-dimensional structure always existed on the surface of the glass microscope slide. An
adjustment of the microscope objective, however, revealed that additional aggregates did not
deposit on the underside of these clusters until approximately 50% of the surface of the glass
microscope slide was covered.
The deposits of carbon black from a suspension with 15 g/L of quinoline were similar to
Figure 3. After 5 minutes, a few particles were randomly distributed on the surface of the glass
10
microscope slide. After 10 minutes, the deposition of particles was mainly adjacent to existing
particles, and bridging began to occur at 60 minutes.
Figure 6 compares particle deposition without polar compounds and with phenol and
quinoline at 10 g/L and 15 g/L (0.11 and 0.12 M). Even though phenol is acidic and quinoline is
basic, both additives had a similar effect on deposition of carbon black.
Physical Properties of the Medium
The dielectric constant of pure kerosene was compared to solutions of kerosene with
phenol and quinoline at different concentrations, as shown in Table 1. Although kerosene was
non-polar and had a very low dielectric constant, the addition of either polar additive slightly
reduced the dielectric constant of the medium. The loss factor, which is used to describe the
energy absorption behavior of a material, increased in the presence of 10 mg/L phenol and in the
presence of 7 and 15 g/L quinoline. The loss tangent is the ratio of the loss factor to the dielectric
constant. The measurement uncertainty of the dielectric constant was estimated to be less than
±10%, and the measurement uncertainty of the loss factor was estimated to be less than ±15%
(Tinga 1998). The electrical conductivity of each solution is shown in Table 2. The solutions
containing polar additives had slightly lower conductivities than pure kerosene, although the data
show that regardless of the presence or absence of a polar additive, the solutions were not good
conductors. The changes in the values of the dielectric constant and electrical conductivity in the
presence of polar additives were not significant enough to account for the differences in particle
deposition.
Deposition of Kaolin Particles
Figure 7 compares the deposition of kaolin particles at a concentration of 10 mg/L to that
of carbon black particles at a concentration of 10 mg/L. The kaolin particles deposited randomly
11
on the surface of the glass slide during the first three to five minutes of the experiment. Very few
additional particles deposited on the glass slide, however the few particles that did deposit on the
surface of the microscope slide after this time did not do so adjacent to existing particles. After 2
hours, only 9.3% of the glass microscope slide was covered with kaolin particles. The difference
in deposition between carbon black and kaolin indicates that the surface properties of the
particles themselves are major contributors to the particle deposition process in non-aqueous
media.
Discussion
The data in Figures 1 and 2 show that the curves that describe the deposition of carbon
black particles suspended in kerosene have a definite S-shape. This observation suggests that
single particles were able to adhere randomly to the glass slide quite rapidly at the start of the
experiment, while subsequent deposition was due to adhesion of particles immediately adjacent
to particles that had previously adhered to the surface of the glass microscope slide. The final
stage was formation of 3-dimensional clusters of particles. The combination of these three stages
of deposition resulted in an S-shaped curve. The changing rates of deposition that occur under all
conditions in this study indicate that the interactions between the particles and the media are
quite complex. The initial rapid deposition, followed by a reduction in adhesion of particles, was
consistent with electrostatic attraction as observed by Chowdiah et al. (1981). They found that
the rate of filtration of carbon black particles in a packed bed declined after the surface charge of
the packing had been neutralized by the deposition of particles with opposite charge. The
subsequent preferential attachment of particles adjacent to particles already deposited on the
surface showed that particle-particle interactions were more favorable than interaction with the
12
glass surface. This favorable particle-particle interaction eventually led to bridging and three-
dimensional deposits.
When either phenol or quinoline were present in the liquid medium, more particles
deposited on the surface of the glass slide than without these polar compounds. Aggregation of
particles was not responsible for the increased deposition in the presence of phenol, since
aggregation did not occur until after the particles exited the glass cell. Aggregation did play a
role, however, in the increased deposition of carbon black particles in the presence of quinoline.
The aggregates consisted of approximately 10 particles. Since the aggregates were spherical, the
area covered by each aggregate is equivalent to that of approximately 3 or 4 single particles.
Thus, the aggregates would cover more of the area of the slide during the initial random
deposition period. Additional aggregates then had a larger “target” to adhere to, since additional
particles tended to deposit adjacent to existing particles. In all cases, i.e. kerosene only and with
addition of phenol or quinoline, most of the observed deposition was due to particle-particle
interactions, giving distinct growth of clumps of particles on the surface. Consequently, the
increase in deposition with increasing concentrations of phenol and quinoline was due to more
favorable particle-particle interactions. The extreme case was quinoline, where the particles
aggregated prior to deposition on the glass surface.
The changes in particle behavior cannot be attributed to changes in the properties of the
liquid medium. The dielectric constant and electrical conductivity of the kerosene solutions were
measured, but the changes in the physical properties were too small to explain changes in
particle behavior. The results in Tables 1 and 2 show that the addition of either phenol or
quinoline caused a slight reduction in the value of the dielectric constant and no change in the
electrical conductivity, except possibly the 10 g/L phenol solution. The uniformly low
13
conductivity was consistent with the theory of conductivity in non-aqueous media, which
identifies charge carriers in low-dielectric media as micelles or large macro-ions, rather than
weakly polar solutes (Morrison, 1993).
Although the solutions were prepared and stored under low relative humidity, Morrison
(1993) has pointed out the difficulty of completely eliminating moisture. Trace amounts of water
in the solutions were, however, unlikely to alter the behavior of the carbon-black suspensions.
None of the suspensions showed a significant increase in conductivity, which would have
signalled micelle formation. Suspensions of hydrophobic particles, such as carbon black, are
generally unaffected by low levels of contamination by water, unlike hydrophilic mineral
surfaces (Morrison, 1993).
Since kerosene itself is nonpolar and does not tend to carry a charge, it is likely that the
trace amounts of water were the source of the double layer repulsion when pure kerosene was
used. At low concentrations, the water molecules would most likely dissociate into protons and
hydroxyl groups, which would adsorb onto the surface of the particles (Kitahara 1984). When
either phenol or quinoline was added to the suspension, the protons and hydroxyl groups
interacted with the additive, thus favoring deposition of particles onto the glass slide.
Another explanation for the role of phenol and quinoline is that these compounds
neutralized charges within the solution, leading to a reduction in the polarization ability of the
mixtures (Tinga 1998). This would mean that the condition imposed by van der Hoeven and
Lyklema (1992), that double layer repulsion could occur only if the medium had a “sufficiently
high ionic strength”, was met when pure kerosene was used as the medium. Thus, in the absence
14
of a polar additive, double layer repulsion would exist, thereby suppressing the attachment of
particles to the glass surface. When a small amount of either phenol or quinoline was added to
the medium, the neutralization of charges within the suspension reduced the effect of the double
layer repulsion, which favored deposition.
Deposition of the kaolin particles on the glass slide was not very favorable, as the
maximum particle coverage on the glass slide was 9.3% at the end of the experiment. After the
random deposition period, subsequent deposition did not occur adjacent to existing particles. The
decreased deposition of the kaolin particles, which had an average diameter 2.5 times greater
than the carbon black particles, may be due to its larger size, its surface charges, or both.
Submicron particles rely on Brownian motion to attain a surface, with smaller particles moving
faster than larger ones. The DLVO theory predicts that deposition depends on particle size,
however, work conducted by Elimelech and O’Melia (1990) suggests that this may not be true. It
is possible that in this study, the force with which the particles entered the glass cell was
sufficient to overcome any particle size limitations that would repress the diffusion of particles
out of the suspension onto the glass slide. This would have to be verified by conducting more
experiments involving a single type of particle with different well-defined size distributions.
The kaolin particles were more hydrophilic than the carbon black particles due to the
presence of hydroxyl groups on their surfaces. This would imply that electrical charges on the
surface of the particles played a role in deposition. As reviewed by Morrison (1993), there is
some dispute in the literature about whether or not particles suspended in nonaqueous media can
be charged. One view is that the sign of the charge of a certain particle may be either positive or
negative, depending on the basicity or acidity of the medium in which it is suspended. Kitahara
(1984) found that carbon black suspended in either benzene or cyclohexane with AOT carries a
15
negative charge, TiO2 suspended in cyclohexane with AOT carries a positive charge, carbon
black suspended in benzene with Mg(AOT)2 carries a positive charge, and TiO2 suspended in
cyclohexane with Mg(AOT)2 carries a positive charge. Thus, if the surfaces of carbon black and
kaolin suspended in kerosene carry opposite charges, differences in their deposition should be
expected.
Regardless of the relative role of the many factors involved in particle deposition in
nonaqueous media, the observations made in this study provide a starting point from which a
mechanism describing this process may be developed. The extent of particle deposition will
depend on the concentration of polar compounds, including water, in the medium, the ability of
the polar compounds to neutralize charges within the medium, and the surface properties of the
particles. Further research into the net effects of these components must be conducted if the
overall mechanism is to be fully understood.
16
References
Chan et al., 1994 ??
Chung, K.H.; Xu, S.; Gray, M.R.; Zhao, Y.; Kotlyar, L.; Sparks, B. “The chemistry, reactivity
and processability of Athabasca bitumen pitch.” Rev. Process Chem. Engin. 1, 41-79
(1998).
Chowdiah, P., D.T. Wasan, and D. Gidaspow, “Electrokinetic Phenomena in the Filtration of
Colloidal Particles Suspended in Nonaqueous Media”, AIChE Journal 27 (1981) 975-
984.
Elimelech, M. and C.R. O’Melia, “Kinetics of Deposition of Colloidal Particles in Porous
Media”, Environmental Science and Technology 24 (1990) 1528-1536.
Hoeven, Ph.C. van der and J. Lyklema, “Electrostatic Stabilization in Non-Aqueous Media”,
Advances in Colloid and Interface Science 42 (1992) 205-277.
Kitahara, A., “Nonaqueous Systems”, In: Surfactant Science Series Volume 15: Electrical
Phenomena at Interfaces. Fundamentals, Measurements, and Applications, A. Kitahara
and A. Watanabe, Eds., Marcel Dekker, New York (1984) 119-143.
Koyama, H., Nagai, E., Torii, H. and Kumagai, H. Oil Gas J. 1995, 93(47), 68.
Morrison, I., “Electrical Charges in Nonaqueous Media” Colloids and Surfaces A:
Physicochemical and Engineering Aspects 71 (1993) 1-37.
Tian, B.Q., W.R. Tinga, and W. Xi, “Single Frequency Microwave Dielectric Heating and
Measuring”, Materials Research Society Symposium Proceedings 269 (1992) 83-89.
Tinga, W.R., “Rapid High Temperature Measurement of Microwave Dielectric Properties”,
Materials Research Society Symposium Proceedings 269 (1992) 505-516.
Tinga, W.R., personal communication (1998).
17
Vatistas, N., “Particle Adhesion to Surface Under Turbulent Flow Conditions”, In: Particles on
Surfaces 3, K.L. Mittal, Ed., Plenum Press, New York (1991) 17-27.
Visser, J., “Particle Adhesion and Removal: a Review”, Particulate Science and Technology 13
(1995) 169-196.
Yan, N. and J.H. Masliyah, “Effect of pH on Adsorption and Desorption of Clay Particles at Oil-
Water Interface”, Journal of Colloid and Interface Science 181 (1996) 20-27.
18
Table 1: Dielectric Data Measured at 915 MHz and 20oC Using a Single Frequency
Dielectrometer
Medium Dielectric
Constant
Dielectric Loss
Factor
Loss Tangent
Kerosene only 2.0 0.0034 0.0017
0.1 g phenol/L 2.0 0.0012 0.00061
5 g phenol/L 1.6 0.00086 0.00054
10 g phenol/L 1.6 0.0048 0.0029
7 g quinoline/L 1.6 0.0038 0.0024
15 g quinoline/L 1.8 0.0052 0.0028
Table 2: Conductivity Data Determined from Resistances Measured by an
Electrometer
Medium Resistance (ohm) Conductivity (S/cm)
Kerosene only 8.33 E+10 1.47 E-07
0.1 g phenol/L 8.41 E+10 1.45 E-07
5 g phenol/L 8.87 E+10 1.38 E-07
10 g phenol/L 9.16 E+10 1.33 E-07
7 g quinoline/L 8.40 E+10 1.45 E-07
15 g quinoline/L 8.50 E+10 1.44 E-07
List of Figures
Figure 1. Adhesion of carbon black particles from a suspension in kerosene at particle concentrations from 5 to 20 mg/L.
Figure 2. Adhesion of carbon black particles from a suspension in kerosene at low extent
of surface coverage. Figure 3. Surface coverage by carbon black particles from a 10 mg/L suspension in
kerosene. a) 5 min; b) 10 min; c) 30 min; d) 60 min. Figure 4. Effect of phenol concentration on adhesion of carbon black particles to glass Figure 5. Effect of quinoline concentration on adhesion of carbon black particles to glass Figure 6. Comparison of particle deposition with time from kerosene and solutions with
phenol and kerosene. Figure 7. Comparison of deposition of carbon black and clay particles.
AbstractIntroductionMaterials and MethodsChemicalsImpinging Jet ApparatusData Analysis
ResultsDeposition of Carbon Black Particles from an Impinging JetDeposition with Phenol and QuinolinePhysical Properties of the MediumDeposition of Kaolin Particles
DiscussionReferencesList of Figures