Print ISSN: 1681-6900

Online ISSN: 2412-0758

Volume 40, Issue 9 (Chemical Engineering 12 Article)

Volume 40, Issue 9 (Chemical Engineering 12 Article), September 2022


Research Paper

Produced Water Deoxygenation: Investigation of Nitrogen Purging scheme– Parametric Study – Part1

Salam Al Dawery; Wameath AbdulMajeed; Saada Al Shukaili; Chandramouli Thotireddy; Ibrahim Al Amri

Engineering and Technology Journal, 2022, Volume 40, Issue 9, Pages 1090-1104
DOI: 10.30684/etj.2022.133677.1200

Produced water (PW) is water that comes out of the well with the crude oil during crude oil production. The quality of produced water varies significantly based on the geochemistry of the producing formation, the type of hydrocarbon produced, and the characteristics of the producing well. A well-known obstacle hindering the re-use of the produced water, in different sectors, is the high content of dissolved oxygen (DO) as it can cause corrosion and polymer degradation. In this study, we report 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 concentration 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) was left unremoved which indicates the necessity for elaborating another approach for treating the shallow DO levels.

Experimental investigation on heat transfer in a gas-solid fluidized bed with a bundle of heat exchanging tubes

Zahraa W. Hasan; Jamal Ali; Abbas Sultan; Laith S. Sabri; Maryam Tariq; Hussein Ghalib; Muthanna Al-Dahhan

Engineering and Technology Journal, 2022, Volume 40, Issue 9, Pages 1105-1116
DOI: 10.30684/etj.2022.132101.1094

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 transport 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 under different operating conditions for this reactor. 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 or mathematical models, facilitating the design, scale up, and operation of this reactor.

Review Paper

New Developments in Inhibition of the Sweet Environment in a Variety of Corrosive Media: A Review

Wasan F. Hameed; Khalid H. Rashid; Anees A. Khadom

Engineering and Technology Journal, 2022, Volume 40, Issue 9, Pages 1117-1130
DOI: 10.30684/etj.2022.132127.1093

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 corrosion-prevention 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.

Use of TiO2 in Photocatalysis for Air Purification and Wastewater Treatment: A Review

Seba S. Mohammed; Zainab Y. Shnain; Mohammad F. Abid

Engineering and Technology Journal, 2022, Volume 40, Issue 9, Pages 1131-1143
DOI: 10.30684/etj.2021.131177.1015

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.

Research Paper

Desulfurization of Real Diesel Fuel onto Mesoporous Silica MCM-41 Implementing Batch Adsorption Process: Equilibrium, Kinetics, and Thermodynamic Studies

Ammar T. Kadhum; Talib M. Albayati

Engineering and Technology Journal, 2022, Volume 40, Issue 9, Pages 1144-1157
DOI: 10.30684/etj.2022.132385.1110

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.

Hydroisomerization of n-Heptane in a Fixed-Bed Reactor Using a Synthesized Bimetallic Type-HY Zeolite Catalyst

Younus H. Khalaf; Bashir Y. Sherhan; Zaidoon M. Shakour

Engineering and Technology Journal, 2022, Volume 40, Issue 9, Pages 1158-1170
DOI: 10.30684/etj.2022.132491.1124

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.

Improved Water-Based Mud Rheological Properties and Shale-Inhibition Behavior by Using Aluminum Oxide and Iron Oxide Nanoparticles

Hasan A. Abbood; Ibtehal K. Shakir

Engineering and Technology Journal, 2022, Volume 40, Issue 9, Pages 1171-1178
DOI: 10.30684/etj.2022.134176.1226

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.

Review Paper

Recent Development in Hydrodynamic and Heat Transfer Characteristics in the Three-phase Fluidized-bed System

Omar S. Mahdy; Amer A. Abdulrahmn; Jamal M. Ali

Engineering and Technology Journal, 2022, Volume 40, Issue 9, Pages 1179-1204
DOI: 10.30684/etj.2022.132506.1125

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.

Research Paper

Hydrodynamic Properties Investigation of Ebullated Bed Reactor Using Non-Newtonian Liquid

Zahraa S. Hassan; Asawer A. Al Wasiti; Zainb Y. Shnain; Peter Philib

Engineering and Technology Journal, 2022, Volume 40, Issue 9, Pages 1205-1215
DOI: 10.30684/etj.2022.132400.1113

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 three-phase (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.

Review Paper

Bio-Treatment Technologies of Produced Water: A Review

Rana A. Azeez; Firas K. Al-Zuhairi

Engineering and Technology Journal, 2022, Volume 40, Issue 9, Pages 1216-1230
DOI: 10.30684/etj.2022.131480.1040

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 bio-treatments, 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 bio-treatments 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. 

Remove Liquid Radioactive Wastes Utilizing Nanofiltration, Ultrafiltration, and Microfiltration Membranes

Alanood A. Alsarayreh; Taisir K. Abbas; Saleh O. Alaswad; Sabad e-Gul; A D. Bajoga

Engineering and Technology Journal, 2022, Volume 40, Issue 9, Pages 1231-1259
DOI: 10.30684/etj.2022.134025.1218

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.

Research Paper

Produced Water Deoxygenation via Nitrogen Purging Scheme– Parametric Study – Part 2

Salam K. Al Dawery; Wameath S. AbdulMajeed; Saada Al Shukaili; Chandramouli Thotireddy; Ibrahim Al Amri

Engineering and Technology Journal, 2022, Volume 40, Issue 9, Pages 1260-1274
DOI: 10.30684/etj.2022.134758.1248

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.