Engineering and Technology Journal

Produced water (PW) is water that comes out of the well with the crude oil during crude oil production. A well-known obstacle hindering the reuse of the produced water in different sectors is the high dissolved oxygen (DO) content as it can cause corrosion and polymer degradation. This study reports the experimental investigations for de-oxygenating samples of PW collected from Omani oil fields via a gas lift unpacked and packed column. Two types of packing (polyethylene rushing rings and spherical glass balls) were used. Upon treating the PW samples grafted with different concentrations of polyacrylamide; 100-500 ppm, through different purging techniques at various N2 throughputs, a considerable reduction in the content of the dissolved oxygen (from saturation level to less than 1 ppm) was detected in the first duration (3 minutes). Upon examining purging durations up to 300 minutes, the DO removal efficiency was slightly improved; however, residues of DO (approaching 0.5 ppm) were left unremoved, indicating the necessity for elaborating another approach for treating the shallow DO levels.

A fluidized bed reactor is commonly used for highly exothermic reactions for
different chemical industrial processes. However, inefficient removal of the
generated heat due to the exothermic reaction can seriously influence reactor
performance. Hence, quantifying and understanding the heat transfer phenomena
in this reactor is essential to enhance the performance of the reactor and,
consequently, the chemical process. To achieve a better quantification and
understanding of the heat transfer in this reactor, an advanced heat transfer
technique has been used in this study to quantify the impact of the presence of the
cooling tubes on the local heat transfer coefficient at four radial positions (r/R =
+/- 0.58, +/- 0.03) at an axial height of H/D =15 cm from the distributor plate with
a wide range of superficial gas velocities (0.2-0.48). It has been found that the local
heat transfer coefficient in the fluidized bed reactor equipped with a bundle of
vertical tubes increases significantly as superficial gas velocity increases at the
wall region, while different behavior was noticed at the center of the reactor.
Moreover, the results show that the local heat transfer significantly decreases at
the reactor's core region for all studied superficial gas velocities. Furthermore, the
new tube arrangement offers a uniform local heat transfer profile for all studied
operating conditions. The obtained new high-quality experimental data for the
local heat transfer coefficient in a fluidized bed reactor equipped with a bundle of
tubes can be used for validation CFD simulations, developing mathematical
models, facilitating design, scale-up, and operation of this reactor.

This paper aims to look at how pipeline steel and crude oil storage tanks resist
corrosion in aqueous carbon dioxide (CO2) environments. To this aim, we have
studied different inhibitors, particularly the heterocyclic inhibitor, which is used
to prevent mild steel corrosion in various situations. On mild steel, the corrosionprevention
mechanism of heterocyclic inhibitors is also investigated. CO2
corrosion is the most frequent and dreaded type of corrosion in the oil and gas
industry, and corrosion inhibitors are the most effective way to fight CO2
corrosion in mild steel. Nonetheless, continual exposure to pollutants and
corrosion causes such as sulfur and chromate on pipeline surfaces is unavoidable.
Because of their toxicity, commercial corrosion inhibitors are being used less
frequently to protect the environment. As a result of the advent of "green"
chemistry and fruit waste, both of which have been demonstrated to be efficient
corrosion inhibitors, plant extracts have become popular. This research aims to
compile a list of carbon dioxide corrosion inhibitors that have been proved to
protect against this type of attack. The material on this page is relevant to the gas
and oil industries, which rely on steel pipelines and crude oil tanks to transport
oil and gas products. This study will also help develop better CO2 corrosion
inhibitors for the gas and oil industries.

This study reviews recent research on the synthesis and application of titanium dioxide (TiO2)-based photocatalysts for environmental applications. The principles of non-homogenous photo-catalysis include utilizing a solid semiconductor, such as titanium dioxide Nano or macro, to form a stable suspension (heterogeneous phase) at the impact of irradiation to elevate a reaction at the surface interface of the different phases in the system. Recently, titanium dioxide has been considered the better semiconductor in non-homogenous photoinduced treatment. TiO2-based photocatalysts have broad applications for industrial processes because of their exceptional physicochemical properties. Nevertheless, having a narrow band near the ultraviolet region limits its applications within visible radiation. As a result of this, there have been considerable research efforts to improve the visible light tendency of TiO2 through modifications of its optical and electronic properties. Several strategies, such as coupling TiO2 tightly and incorporating other metallic components during synthesis, have increased the bandgap of TiO2 for visible light applications. Moreover, an overview of nanotechnology that could enhance the properties of TiO2-based catalysts in an environmentally friendly way to decompose pollutants is also presented. The various TiO2-based photocatalysts have wide applications in degrading recalcitrant pollutants in the air, water, and wastewater treatment under visible light.

In the current work, sulfur was removed from actual diesel fuel containing 1.2 wt.% sulfur from the Al-Dura Oil Refinery (Iraq), which was studied using adsorption desulfurization with the spherical mesoporous silica MCM-41. This study investigated the effects of different operating conditions, including the dose of MCM-41 (0.04-0.2 gm), time (60-180 min), and temperature (30-70°C). The optimal working conditions were determined to be 0.4 gm MCM-41, 180 min, and 70°C. After exploring the isotherm models of Langmuir, Freundlich, and Temkin, Temkin models with a correlation coefficient (R2 = 0.9996) were selected to best represent the stable data. The kinetics of sulfur components on MCM-41 were studied using pseudo-first-order and pseudo-second-order kinetic models and intra-particle diffusion. A pseudo-first-order adsorption kinetic model with a correlation coefficient (R2) of 0.9867 can accurately represent the adsorption process. Gibbs free energy (ΔGo), enthalpy (ΔHo), and entropy (ΔSo) were calculated as thermodynamic parameters. The adsorption of total sulfur-containing compounds onto mesoporous silica was spontaneous, endothermic, and increased the irregularity of the sulfur compounds on the surface of the adsorbent. The total sulfur content of actual diesel fuel was reduced from 1.2% to 0.84%, corresponding to a desulfurization efficiency of 29.72%. Consequently, the findings of this study might be used as a starting point for future research.

The synthesis of NaY-zeolite was performed hydrothermally. The preparation of the bifunctional catalysts was achieved by loading NH4Y-zeolite with a cheap Zr metal, as a second loading metal, with tiny amounts of Pt to compose a Pt-Zr/Y-zeolite catalyst. Different characterization methods (i.e., XRD, SEM, EDX, BET, and AFM) were used to investigate the catalyst properties. The catalytic performance was studied by performing the hydroisomerization of n-heptane in a gas phase at a temperature of 275°C and atmospheric pressure in a fixed-bed reactor. The GC-FID results of the products confirmed the positive role of Zr in enhancing the catalytic features, as reflected by the increase in the isomerized products and the decrease in the unwanted by-products. Incorporating 1.0wt%Zr with 1.0wt% of Pt significantly improved the activity and selectivity and increased the yield of branched alkanes. This was achieved because the addition of zirconium provided an extraordinary Lewis acidity to the zeolite-framework structure and simultaneously took advantage of the electronic and catalytic properties of Zr and Pt metals to enhance its novel catalytic features. This reduced the amount of Pt metal and halved the cost of the catalyst. In addition, the bimetallic catalyst (HY-zeolite loaded with 1wt%Pt & 1wt%Zr) achieved values of 74.2, 78.8, and 58.5mol% for conversion, selectivity, and yield, respectively. The conversion was improved to a level close to 2wt% Pt/HY-zeolite catalyst, while selectivity was not significantly decreased from that of
2wt% Zr/HY-zeolite catalyst, reaching a yield level of isomers close to that of 2wt% Pt/HY-zeolite catalysts.

Nanotechnology can be used to develop drilling fluid additives that can improve
the drilling fluid's properties. Using two types of nanoparticle (NP) additives in
water-based drilling fluids have been studied in this paper. Three major drilling
mud systems, namely potassium chloride (KCl) as a basic mud, KCl/aluminum
oxide (Al2O3) NPs, and KCl/iron (Fe2O3) NPs, were prepared and studied for
enhancement of rheological properties and shale inhibition. It was found that the
drilling mud contained NPs in concentrations of 0.25, 0. 5, 0.75, and 1 g. Al2O3
and Fe2O3 NPs added to KCl/polymer mud systems resulted in a 50% and 30%
change in shale volume, respectively. The results demonstrated that
incorporating NPs into the KCL mud system enhanced shale inhibition. Adding
NPs to the KCL-WBM increased yield point, plastic viscosity, and gel strength.
The COF of KCL-polymer was reduced by 48% and 34% when added Al2O3 and
Fe2O3 NPs at 0.5 and 0.75g, respectively. When Al2O3 and Fe2O3 NPs were
used, particularly at 1g, the amount of mud filtration decreased from 13.1ml to
8.8 ml and 8.4 ml, respectively. Overall, it was found that adding Al2O3 and
Fe2O3 NPs to the KCl-WBM can improve rheological, swelling, and filtration
properties as well as lubrication.

Gas–liquid-solid fluidized beds are broadly utilized in the petrochemical, pharmaceutical, refining, food, biotechnology, and environmental industries. Due to complex phenomena, such as the particle-particle, liquid-particle, particle-bubble interactions, complex hydrodynamics, and heat transfer of three-phase (gas-liquid-solid) fluidized beds, they are incompletely understood. The ability to accurately predict the essential characteristics of the fluidized-bed system, such as hydrodynamics, individual phase mixing, and heat transfer parameters, is necessary for its successful design and operation. This paper investigates the pressure drop, minimum fluidization velocity, phase holdup, heat-transfer coefficient of a fluidized bed reactor, heat transfer studies, CFD simulation, and the effect of these parameters on the extent of fluidization. Many variables (fluid flow rate, particle density and size, fluid inlet, and bed height) affect the fluidizing quality and performance of the fluidization process. The hydrodynamics parameters, mixing of phases, and the behavior of heat transfer with various modes of fluidization were investigated to predict hydrodynamics parameters. Several publications have demonstrated the utility of (CFD) in explaining the hydrodynamics, heat, and mass transfer of fluidized beds. Principles of measurement, details of the experimental configurations, and the applied techniques by various researchers are also presented. Feng's model was statistically validated using experimental data that was both time-averaged and time-dependent. Furthermore, this model successfully predicted the instantaneous flow structures, which should provide strategies for the best design, scale-up, and operation in fluidized bed columns. The divergence between the simulated and observed values can be reduced by better understanding the fluidized bed's nature

The importance of using EBR has been renewed recently due to the sharp
increase in heavy feedstocks sent to refineries and the hydrocracking process.
Most of these feedstocks have a non-Newtonian behavior. The performance of
this type of reactor using non-Newtonian liquid is complicated and has not been
covered well yet. Hence, the present work is devoted to elucidating the effect of
the non-Newtonian behavior of fluid on the hydrodynamic properties of a threephase
(gas-liquid-solid) reactor under operating conditions of different values of
gas velocity (2, 4, 6) cm/sec, liquid velocity (0.9, 1.39, 1.8, 2.3) cm/sec, and
recycle ratio (1.5, 2, 2.5). The study observed the effect of non-Newtonian
behavior using polymethyl Cellulose (PMC) at different concentrations (0.1, 0.2,
0.3, and 0.4) wt%. The pressure gradient method was used to elucidate the
minimum liquid fluidization velocity and to estimate hold up, while the imaging
method was used to measure the bubble's size. The results showed that the higher
the gas velocity, the lower the minimum liquid fluidization velocity. As the
intensity of the non-Newtonian behavior increased, gas velocity showed the
opposite effect. The results also showed that increasing the velocity of liquid and
gas and the intensity of the non-Newtonian increase the gas hold-up. The bubbles
characteristics, represented by bubble size results, show that small bubbles
appear at low gas velocities, and these bubbles collapse as gas and liquid
velocities increase as well as liquid viscosity.

Petroleum is a vital source of energy for most human activities. The growth of
the oil and gas sector is associated with releasing a significant amount of
produced water (PW) from onshore and offshore fields. Thus, undesirable toxic
pollutants in produced water have become a major concern for those concerned
with environmental issues. Therefore, interest in recycling and beneficial reuse of
pollutants has increased due to large amounts of PW. In general, various physical
and chemical technologies and bio-treatments for PW or combined between them
are applied. Bio-treatment is preferred due to its efficiency and eco-friendly
compared with other PW treatments. To clarify the prospective role of PW biotreatments,
this review highlights the main bio-treatment technologies in aerobic
and anaerobic conditions to reduce salinity, organic components, and toxicity
from PW. Also, challenges of environmental factors for PW and future research
directions are included. Activated sludge is an essential part of aerobic biotreatments
of polluted water as inoculum rich in microbial cells that can degrade
pollutants. Membrane bioreactors (MBR), fluidized bed bioreactors (FBBs),
aerated biological filter (BAF), and aeration lagoons are also reviewed.
Moreover, bio-treatments are extended to include anaerobic conditions.
Furthermore, bio-treatment techniques can treat organic compounds of
wastewater, especially with low oil concentrations and poor solubility that cannot
be treated with conventional treatments.

Radioactive waste is generated from fuel cycle processes in nuclear reactors and
nuclear power plants (NPPs) in electrical power production, radioisotope
manufacturing in nuclear research centers, and medical, industrial, and
agricultural applications. Also, natural chain-linked radioisotopes (NORM) are
generated from processing and burning fossil fuels and producing oil and natural
gas. Therefore, a planned and integrated radioactive waste management strategy
must be adopted to protect human health and the environment from the dangers
of this waste through published research on a comprehensive radioactive waste
management strategy and the testing and dissemination of several treatment
options. The main objective is to draw the scientific community's attention to the
possibility of using pressure-driven membrane separation in treating radioactive
wastewater compared to conventional methods. This short review addresses
developments in the treatment and removal of radioactive effluents (LRWs) by
pressure-driven membrane methods and improvements in routine treatment of
dissolved radioactive ions by chemical treatment of the feed solution followed by
membrane separation. Also, recent advances in treating radioactive waste use
nanoparticles (NPs) incorporated in polymeric membranes.

In this following up paper, we present our findings by examining a pilot scale gasification column and applying nitrogen purging for samples of produced water grafted with different polyacrylamide concentrations (100 – 500 ppm). Upon applying a semi-batch, counter-current scheme for a series of experiments on packed gas-lift column, zero ppm level of dissolved oxygen (DO) was reached within less than 1 minute of nitrogen purging from the start time applied for solutions with viscosity less than 10 mPa.s and using the inline measuring scheme. However, zero ppm DO level was not reachable when purging produced water (PW) samples grafted with fresh polyacrylamide with a viscosity higher than 10 mPa.s. Nonetheless, the residues of DO were detected by offline measuring after examining the higher viscosity samples in the shallow limit (less than 0.4 ppm DO) and reached zero ppm when applying the inline measuring scheme. Two operation mode schemes, circulation, and once-through, were applied. Upon investigating the once-through contact scheme, the adopted nitrogen purging method was effective in reaching zero ppm level in less than 2 minutes, which is an excellent result compared with other well-known treatment techniques.