Two problems relating to the processing of solid streams are
treated in two sections.
The first section is the study of heat transfer between an
immersed cylinder and a moving bed of solids: An instrumented heated
cylinder was placed in the flow stream of a moving bed of solids with...
Hydrogen sulfide emissions from the smelt dissolving tank area
of some kraft pulp mills exceed environmental limitations. There are
two main factors to consider in determining the cause of these emissions:
chemical equilibria and rate processes. This investigation
considers the chemical equilibria in the smelt shatter jet area (system
A)...
Mass transfer from a single rising gas bubble in water may be analyzed by numerical methods. In this study the simultaneous differen- tial equations which describe two component mass transfer from a rising gas bubble are solved by numerical integration. This is accomplished using a computer model which employs a...
Two packages of subroutines were developed to perform material
balances on chemical processes using the simultaneous modular
approach and the equation-based approach. The performances of these
packages were compared for five different processes under at least
two conditions: one with no design specifications, and one with two
or more design...
A review of Single-Input Single-Output Internal Model Control
(IMC) is presented, showing its relationships to the Dahlin
algorithm, PID type controllers for simple models with and without
deadtime and Smith predictor control.
The effect of errors in the time constant and the gain of a
first order model with deadtime...
Two new experimental techniques are presented which enable the
direct measurement of heat transfer coefficients in fine particle
gas fluidized beds.
The first technique uses fine electrically heated Alumel wires
to probe fluidized beds of fine particles. The wires varied in
diameter from 50.8 to 813μm while the bed material...
A study of nucleate boiling of water, four alcohols and
three ethanol-water mixtures was conducted in a vertical
thermosiphon reboiler. The test section consisted of a 1/2-
inch diameter electrically heated stainless-steel rod
jacketed by a 15-inch long pyrex glass tube. Two different
inside diameters of the glass tube corresponding...
The fouling characteristics of cooling tower water
containing various corrosion inhibitors and other additives
on heat transfer surface have been investigated. Corrosion
inhibitors investigated included zinc-chromate and
phosphates. In addition, additives including polyacrylate
and phosphonate (HEDP and AMP) were used to determine their
effectiveness as antifoulants.
The tests were conducted...
Nucleate boiling of water in a vertical annulus was
studied. The test section was entirely of stainless steel
construction and was formed by a length of stainless steel
tubing with a stainless steel heater rod centered in it. Two
test sections with length to diameter ratios of 18 and 33...
In designing a solubility based separation process
for solvent recovery of an organosolv pulping process, the
phase behavior of polymeric lignin molecules in alcohol -
water mixed solvent should be known. In this study,
sodium lignin sulfonates (NaLS) samples were fractionated
into three different molecular weight fractions using a
partial...
The surface renewal rate from Danckwerts' theory and
the effective interfacial area between gas and liquid per
unit packing volume in a packed absorption tower were
evaluated for the absorption of carbon dioxide into
carbonate/bicarbonate buffer solution accompanied by a
pseudo-first order chemical reaction. The rate of chemical
reaction in...
The research undertaken in this study deals with three topics related to the prediction of thermodynamic properties of electrolytes in aqueous solutions. In the first, Pitzer ion interaction parameters for 304 single electrolytes were evaluated from recently published osmotic coefficient data at 25°C by using multiple regression analysis to fit...
Hemicellulose hydrolyzate contains many carbohydrate
fractions, the most abundant being xylose, arabinose, and
glucuronic acid. Under mild acid conditions (0.025 -
0.10 M sulfuric acid) and high temperatures (140°C to
200°C) the first two components form furfural through a
series of dehydration reactions. Unlike xylose and
arabinose, glucuronic acid must...
A contactor has been designed and constructed for experimental
studies of mass transfer with or without chemical reaction between
two fluid phases. The contactor is flexible enough to investigate a
wide range of variables affecting mass transfer coefficients. It is
easy to operate; it could be operated either as a...
Ozone was found to quickly reduce the concentration of lead in a prepared
solution when the solution pH of said solution was greater than 7.0. When a solution
having a pH of greater than 7.0 was filtered the concentration of lead was less than
approximately 1.0 ppm. 1.0 ppm is...
Chemical equilibrium is a major factor in many natural and
industrial systems. The ability to predict ionic equilibrium is
extremely valuable in industry in solving problems without the costs
involved in full scale experiments. An example of an application in
the pulp and paper industry is the prediction of non-process...
Various antifoulant treatment programs and the
considerations necessary for the effective use of such
programs were examined.
Two different groups of tests, with and without
iron contamination, have been carried out on the
effectiveness of several of the state-of-the-art
copolymers (PA, HEDP, AA/HPA, AA/MA, SS/MA and AA/SA) in
the inhibition...
Heat transfer to moving packed beds of solids has been studied
extensively but predictions are usually specific to the experimenter's
own equipment. In order to obtain a more general predictive equation,
the heat transfer coefficient was measured for a single vertical tube
immersed in a moving packed bed of glass...
Problems with aluminosilicate scales in pulp and paper recycle streams create an
interest in the formation mechanism and the chemical equilibrium of aluminosilicates.
Evaluating solubility data from a system containing Na⁺ CI⁻, and OH⁻ ions as well
as aluminium and silicon compounds, allowed to elucidate the characteristics of the
aluminosilicate...
The effects of possible operating variables such as flow rate, surface temperature, bulk temperature, solids contents, sulfate addition and pH on the fouling of sulfite spent evaporators were studied. The study pointed out that the Ca⁺⁺ concentration difference between heated surface and bulk is the most important factor for fouling...
The effect of over-oxidation on periodate oxidation
of cellulose was studied. It was found that the over-oxidation
process has a significant effect on the overall
reaction. An integrated rate equation was formulated.
The oxidation of internal glucose units is second-order
overall, first order with respect to both periodate and
cellulose;...
A column which contains a series of three fluidized
beds for counter-current contacting of solid particles with
a gas stream has been studied. Successful, independent
control of solids holdup on each stage has been achieved by
manipulating the field of a magnetic distributor-downcomer
on each stage. Two methods to manipulate...
Measurable surface parameters which may be related to the response evoked upon contact with biofluids have been suggested to provide direction for characterization, prediction, and ultimate control of biofluid behavior at interfaces. With respect to fouling of heat exchange equipment by biofluids, such properties may be useful for the development...
Cellulosic biomass materials have three principal
components: cellulose, hemicellulose, and lignin. Under
mild acid conditions and high temperature, the first two
components yield a variety of sugars: hexoses and pentoses,
which are subject to decomposition on continued exposure to
hot dilute acid. In the process hexoses yield
hydroxymethylfurfural (HMF) which,...
The bacterium most frequently used in microbial
leaching processes and studies is Thiobacillus
ferrooxidans. Applications of this bacterium include the
treatment of coal, low-grade ores and industrial solid
wastes for the solubilization of pyrite and other trace
metals associated with sulfides. The goal of this study
was the development of...
Illinois coal ground to 80-200 mesh was leached
with a low phosphate, high nitrogen medium containing a
mixture of Thiobacillus ferrooxidans and thiooxidans in a
fluidized bed. Coal slurries of 20-160 g/L were treated
in a 5 cm ID, 9.5 m high continuous loop bioreactor with
crossovers at top and...
The temperature-time-location relationships during steam conditioning and pressure
treatment of timber poles have been studied and mathematical models that take into
account both the thermal properties of the poles and the parameters of the treatment
process have been developed. Although much work has been previously done in this
area, the...
A systematic study of the fouling characteristics of organic fluids was conducted in an annular test section. The study consisted of four main parts. First, the effect of key factors such as surface temperature, velocity, concentration, and oxygen on fouling from the system styrene-heptane-polystyrene was investigated. While surface temperature increased...
A simple heat exchanger network has been studied as
an example of a dynamically interactive process. The
process is relatively simple, requiring only temperature
measurements and flow rate manipulations. Equations are
presented for the design of a physical process having a
specified steady-state Relative Gain Array and specified
dynamic characteristics....
The effect of pH and ionic strength on the equilibrium adsorptive
behavior of β-lactoglobulin onto hydrophobic and hydrophilic
silicon surfaces was studied using ellipsometry. Plots of amount
adsorbed (μg protein/cm²) as a function of protein concentration
(mg/ml) exhibited attainment of plateau values beyond a protein
concentration of 0.250 mg/ml. At...
The fouling characteristics of a desalted crude oil were investigated in a systematic
investigation. There are two main parts in this study, the dry bulk tests (dehydrated crude
oil) and the wet bulk tests (to which desalter brine was added). Three barrels of desalted
crude oil provided by Amoco Oil...
A computer assisted design model, developed for
undergraduate students to teach the basic principles of
humidification design, is developed and presented.
Beginning with the development of the differential
equations, the conversion to numerical code is presented,
followed by a series of applications to mechanical draft
in cooling towers, natural draft...
The principal aim of this study was the use and evaluation of dynamic
modeling techniques to identify mathematical models for cereal drying rates and
quality changes that best describe thin-layer malt drying data. Seven thin-layer
malt drying experiments were performed at the Great Western Malting pilot
facilities, Vancouver, WA. Malt...
Ellipsometry was used to study the effects of surface energetics
and temperature on the equilibrium adsorptive behavior exhibited by
β-lactoglobulin. β-Lactoglobulin isotherms at 25, 37, and 55°C were
constructed for this purpose. The surfaces of acrylic, polycarbonate,
polyester, glass, and #304 stainless steel were contacted with protein
solutions of varying...
The non-ideal aqueous electrolyte simulator (NAELS) is composed of
three major parts: a Newton-Raphson non-linear optimization program written
by Weare, et al (1987); an activity coefficient subroutine for non-ideal
electrolyte systems based on Pitzer's model; and an extensive, user expandable
database. It is robust, stable, and requires neither thermodynamic data...
The purpose of this research is to study the
feasibility of combining reaction and separation in a
membrane separation unit. The asymmetric ceramic membrane
reactor applied to the gas-phase catalytic decomposition
reaction of ammonia from an IGCC (Integrated Gasification
Combined Cycle Processes) gas mixture was simulated in the
temperature range...
This thesis examines the transient performance of packed bed heat
regenerators when very large temperature differences are involved. The
effects of gas temperature on the key gas physical properties of velocity,
density and heat capacity were studied via simulation.
Three models were developed and compared. The first model
(HRKDV) considers...
Y-Zeolite catalysts have the potential to promote the
shape-selective conversion of glucose to oxygenated
hydrocarbons at fairly low temperature (100 to 130°C).
Reaction of glucose solution with H-Y Zeolite catalyst
powder was carried out in a well-mixed batch reactor. This
reaction was studied as a function of reaction time (0...
The adsorption equilibrium and kinetic behavior exhibited
by β-lactoglobulin at silanized silicon surfaces of varying
hydrophobicity were examined using ellipsometry. Adsorption
equilibrium results were used to construct adsorption
isotherms; the adsorbed mass of β-lactoglobulin was observed
to increase with increasing surface hydrophobicity, within a
defined range of hydrophobicity. Adsorption kinetics...
Two basic approaches to reduce computational requirements for solving
distillation problems have been studied: simplifications of the model based on
physical approximations and order reduction techniques based on numerical
approximations.
Several problems have been studied using full and reduced-order
techniques along with the following distillation models: Constant Molar
Overflow, Constant...
This thesis examines the transient response of a packed bed heat
regenerator when heated from an initial uniform bed temperature. Very large
(1700 K) temperature differences were studied as well as the effect of
simultaneous chemical reaction in the gas phase.
First the effects of temperature on physical and transport...
Succinic acid, a low molecular weight dicarboxylic acid was used to leach out
heavy metals from Willamette Valley soil (contaminated separately with lead, copper,
and zinc) in form of water-soluble organo-metal complexes. The research tasks included
developing synthetic contaminated soils representative of those found at Superfund sites
and making heavy...
Black liquor gasification is one of the promising alternatives to
eliminate the drawbacks of the conventional recovery unit of the
kraft process. A numerical model has been developed to simulate an
industrial pilot scale entrained-flow gasifier currently operating at
Tampere, Finland. The objective of the model is to investigate the...
The extraction of pentachlorophenol (PCP) from pressure treated wood
wafers with supercritical carbon dioxide has been studied. Experimental data
were obtained for the effects of pressure (17.5 - 25.0 MPa), temperature (313 - 353
K), flow rate (1 - 3 ml/min at supercritical conditions), and sample size (0.8 x 10...
More than 30,000 potential Superfund sites have been identified. Heavy metals are contaminants at many of these Superfund sites. The average cost of cleanup a single-typical Superfund site currently stands at $20 million, and it is expected that the cost may escalate to $50 million within the next decade. Problems...
In a conventional well-mixed fluidized bed the solids are almost
completely mixed and the residence time for individual particles may vary
between zero and infinity. For materials especially sensitive to the processing
time, a wide distribution of residence time is extremely undesirable. A multi-compartment
fluidized bed was proposed to minimize...
The principal objective of this study was to investigate process simulation and
optimization of an existing offshore natural gas process which needed profitability
improvements. Optimization was done using two alternative approaches: a global
approach (response surface methodology) or a local approach (successive quadratic
programming). The global approach was characterized by...
Steel corrosion in reinforced concrete is a major concern to transportation agencies nationwide because of the expenses incurred for repair and ultimate shortening of bridge life. Cathodic protection (CP), as a remedy, has been applied to reinforced bridges in the US since 1974. However, application of this technique is largely...
Nisin is an antibacterial peptide, which when adsorbed
on a surface can inhibit bacterial adhesion and viability.
The ability of noncovalently immobilized nisin to withstand
exchange by the milk proteins bovine serum albumin, β-lactoglobulin, α-lactalbumin, and β-casein on surfaces that
had been silanized with dichlorodiethylsilane to exhibit
high and low...
Nitrogen evolution during black liquor pyrolysis and black liquor combustion were studied using a laminar entrained-flow reactor. The experimental conditions were 700-1100°C and 0.3-2.2 seconds residence time. The pyrolysis experiments were performed in a pure nitrogen atmosphere. The oxygen concentrations during the combustion of black liquor experiments were 4 and...
Production of dry particles made of titanium dioxide powder and black liquor is
the first step in a newly proposed black liquor treatment process (Frederick et. al., 1992).
This work investigates the granulation processes in a fluidized bed granulator of titanium
dioxide and black liquor. Experiments are performed in a...
Fume, sub-micron aerosal particles in the combustion gases, have been identified
as a cause of extensive plugging and fouling in the heat transfer section of a kraft
recovery boiler in kraft pulp mills. After the deposition on the heat transfer surface,
fume deposits will undergo the sintering process which causes...
Two approaches to reduce computational requirements for solving reactive
distillation problems have been studied: simplification of the model using physical
assumptions and numerical approximation using an orthogonal collocation technique.
The results of a full-order model with time dependent stage molar holdups was
compared to published steady-state experimental data and was...
The goal of this thesis was to develop a process of producing small monodisperse
alginate gel beads. The phenomenon of controlled jet break-up of alginate solution jet
with assisted vibration was used to form uniform sodium alginate droplets which were
subsequently crosslinked with divalent calcium ion to form gel beads....
2 μm average sized silicon powder was nitrided with 90% N₂/10% H₂ in a
fluidized-bed reactor, operated at 1200°C, 1250°C and 1300°C. To fluidize silicon
powder, alumina particles with an average size of 300 μm were used as an inert fluidizing
conditioner. The feasibility and operating conditions of the fluidization...
Laminar entrained flow reactor (LEFR) was used to determine the effect of
temperature and residence time on the distribution of carbon, sulfur and nitrogen between
gaseous and condensed phase products from low temperature pyrolysis of kraft black
liquor. The operating furnace temperatures were between 400°C-600°C where the effect
of condensable...
The importance of two sources of NO formation, nitrogen in combustion air
and nitrogen in the fuel, during black liquor combustion was studied using a laminar
entrained flow reactor. Pyrolysis and combustion experiments were conducted in
nitrogen atmosphere and in a mixture of argon and helium in the composition 99%...