Iraqi Journal of Chemical and Petroleum Engineering

Titanium-dioxide (TiO2) nanoparticles suspended in water, and ethanol based fluids
have been prepared using one step method and characterized by scanning electron
microscopy (SEM), and UV–visible spectrophotometer. The TiO2 nanoparticles were
added to base fluids with different volume concentrations from 0.1% to1.5% by
dispersing the synthesized nanoparticles in deionized water and ethanol solutions. The
effective thermal conductivity, viscosity and pH of prepared nanofluids at different
temperatures from 15 to 30 oC were carried out and investigated. It was observed that
the thermal conductivity, pH, and viscosity of nanofluids increases with the increase
in TiO2 nanoparticle volume fraction. The thermal conductivity of TiO2 nanofluids
significantly increases linearly with increasing particle vol. fraction at different
temperature values and also it was found that the viscosity increases with increasing
particle vol. fraction and decreases with the increase in temperature.

The concept of entransy dissipation was determined for new type of heat exchanger
(shell and double concentric tubes heat exchanger). Three parameters, hot oil flow
rate, temperature of inlet hot oil and pressure drop of system were investigated with
this concept (entransy dissipation). The results showed that the value of entransy
dissipation of oil and of system which represents the summation of entransy
dissipation of both oil and water increased with increasing the flow rate of hot oil and
these values were larger when cold water flow rate was doubled. Also they were
increased with increasing the hot oil inlet temperature at a certain flow rate of hot oil.
Furthermore, the pressure drops for hot oil in both shell side and inner tubes side was
constant and increased according to the increase of its flow rate. At different hot oil
flow rate and a certain hot oil inlet temperature, the entransy of hot oil was increased
with its pressure drop. In order to keep up with modern technology, infrared
thermography camera was used in order to measure the temperatures which were
higher than the temperatures obtained by thermocouples. For that reason the entransy
dissipation was determined with lower values compared with their values obtained by
using thermocouples.

The preparation of low cost activated carbon from date stones and microwave
method by using K2CO3 as chemical activator were investigated.
The prepared activated carbon was used to remove fluoroquinolones antibiotics
from aqueous solution. The characterizations of the activated carbon is represented by
surface area, pore volume, ash content, moisture content, bulk density, and iodine
number. The adsorbed fluoroquinolones antibiotics are Ciprofloxcin (CIP),
Norfloxcin (NOR) and Levofloxcin (LEVO). Different variables as pH, initial
concentrations and contact time were studied to show the efficieny of prepared
activated carbon. The experimental adsorption data were analyzed by Lungmuir,
Freundlich, and Temkin isotherm. The experimental results are described by
Lungmiur isotherm. The kinetic data were fitted to pseudo-first order kinetics,
pseudo-second order kinetics and interparticle diffusion model. The kinetic adsorption
data were best fitted by psuedo-second order kinetic.

Naturally occurring radioactive materials (NORM) contaminated sites at AlRumaila Iraqi oil fields have been characterized as a part of soil remediation project.
Activity of radium isotopes in contaminated soil have been determined using gamma
spectrometer High Purity Germanium detector (HPGe) and found to be very high for
Al-Markezia, Al-Qurainat degassing stations and storage area at Khadhir Almay
region. The activity concentration of samples ranges from 6474.11±563.8 Bq/kg to
1232.5±60.9 Bq/kg with mean value of 3853.3 Bq/kg for 226Ra, 843.59±8.39 Bq/kg to
302.2±9.2 Bq/kg with mean value of 572.9 Bq/kg for 232Th and 294.31±18.56 Bq/kg
to 156.64±18.1 Bq/kg with mean value of 225.5 for 40K. Six hazard indexs radium
equivalent, representative level index, adsorbed dose rate in air, annual effective dose
equivalent, external hazard index, and internal hazard indexes were calculated to
estimate the potential radiological health risk in soil and dose rate associated with it
and found to be high. Screening of contaminated soil was performed to evaluate the
feasibility of particle size separation. The fractions obtained varied between 75 µm
(200 mesh) to 300µm (48 mesh).The results show that the largest weight percent in
fine particle size cut ( -75, -125+75, -250+125) µm is 73.9% and all radium isotopes
are concentrated in 37.5µm particle size while small fluctuations are observed in the
other particle size cuts.

In the present work, asphaltenes and resins separated from emulsion samples
collected from two Iraqi oil wells, Nafut Kana (Nk) and Basrah were used to study the
emulsion stability. The effect of oil resins to asphaltene (R/A) ratio, pH of the
aqueous phase, addition of paraffinic solvent (n-heptane), aromatic solvent (toluene),
and blend of both (heptol) in various proportions on the stability of emulsions had
been investigated. The conditions of experiments were specified as an agitation speed
of 1000 rpm for 30 minutes, heating at 50 °C, and water content of 30%. The results
showed that as the R/A ratio increases, the emulsion will be unstable and the amount
of water separated from emulsion increases. It was noticed that the emulsion of Nk
crude oil became more stable at basic pH range, and reached to completely stabilized
emulsion at pH=12. Whereas Basrah emulsion was stable in both acidic and basic pH
ranges. Results indicated that toluene gave a good solubility for asphaltene, and a
higher water separation for both crude oil emulsions.
A mathematical model to determine the kinetic constants that characterize the
coalescence in the emulsions was also developed.

Drilling with casing (DWC) can be considered as a modern drilling technique in
which both of drilling and casing operations done in the same time by using the
casing to transfer the hydraulic and mechanical power to the bit instead of traditional
drilling string. To overcome oil well control, minimizing the total cost through
enhancing drilling efficiency, drilling with casing was proposed as an enabling
technology.
Two surface sections (17 1/2 - and 12 1/4- inch) were drilled successfully in
Rumaila oil field with casing strings which reached 655m and 1524m measured
depths respectively.
By using DWC technique, the total drill/case phase time was reduced up to 20%
comparing to conventional drilling in the same field .
Drilling both sections with DWC system eliminating the number of trips and
nonproductive time (NPT) related to wellbore instability.

The present work aimed to study the efficiency of thermal osmosis process for
recovery of water from organic wastewater solution and study the factors affecting the
performance of the osmosis cell. The driving force in the thermo osmosis cell is
provided by a difference in temperature across the membrane sides between the draw
and feed solution. In this research used a cellulose triacetate (CTA), as flat sheet
membranes for treatment of organic wastewater under orientation membrane of active
layer facing feed solution (FS) and draw solution (DS) is placed against the support
layer. The organic materials were phenol, toluene, xylene and BTX (benzene,
toluene, and xylene) used as feed solution. The osmotic agent in draw solution was
sodium chloride salt. The membranes have high rejection percentage for NaCl and
organic materials. In this research, the operating conditions that have been studied are:
temperature of draw and feed solution (18 – 45 °C) and the operating time of process
was (0 – 3) hours. It was found that water flux in thermal osmosis process increases
with increasing temperature of draw and feed solution ( by average ratio 1:2), and
decreases with increasing operating time.

The air flow pattern in a co-current pilot plant spray dryer fitted with a rotary disk
atomizer was determined experimentally and modelled numerically using
Computational Fluid Dynamics (CFD) (ANSYS Fluent ) software. The CFD
simulation used a three dimensions system, Reynolds-Average Navier-Stokes
equations (RANS), closed via the RNG k −ε turbulence model. Measurements were
carried out at a rotation of the atomizer (3000 rpm) and when there is no rotation
using a drying air at 25 oC and air velocity at the inlet of 5 m/s without swirl. The air
flow pattern was predicted experimentally using cotton tufts and digital anemometer.
The CFD simulation predicted a downward central flowing air core surrounded by a
slow recirculation zones near the walls for both conditions. Analysis of CFD
simulation revealed that rotation of atomizer resulted in a swirling motion of the
central air core. Simulations results were in good agreement with experimental data.

Design of experiments (DOE) was made by Minitab software for the study of three
factors used in the precipitation process of the Sodium Aluminate solution prepared
from digestion of α-Al2O3 to determine the optimum conditions to a produce
Boehmite which is used in production of ɤ-Al2O3 during drying and calcination
processes, the factors are; the temperature of the sodium aluminate solution,
concentration of HCl acid added for the precipitation and the pH of the solution at
which the precipitation was ended. The design of the experiments leads to 18
experiments.
The results show that the optimum conditions for the precipitation of the sodium
aluminate solution which leads to the production of gamma alumina are 6.5 pH,
Temperature of solution is 90 C and the concentration of the hydrochloric acid (HCl)
is 21%. While all other conditions lead mainly to other phases of alumina which is
mainly epsilon- alumina (ε-Al2O3).