Iraqi Journal of Chemical and Petroleum Engineering
The Iraqi Journal of Chemical and Petroleum Engineering is a quarterly peer-reviewed scientific journal that was established in 2000 by the College of Engineering / University of Baghdad. The Iraqi Journal of Chemical and Petroleum Engineering receives citations in the category of Chemical /Petroleum Engineering and relevant subjects.
University of Baghdad/ College of Engineering
Photocatalytic degradation of a cationic dye using Ag2O@CuO nanoellipsoidal photocatalyst under ultraviolet irradiation
The photocatalysis oxidation process is a promising technology within the series of advanced oxidation processes, which implements light-induced catalysts to generate strong oxidative species to eliminate organic pollutants from wastewater treatment. The Ag2O@CuO photocatalyst was successfully prepared by the co-precipitation method. The developed photocatalyst was characterized using X-ray diffraction, Fourier transform infrared spectroscopy, X-ray fluorescence spectrometer, field-emission scanning electron microscopy, Ultraviolet-Visible diffuse reflectance spectra, and photoluminescence spectra. The Ag2O@CuO efficiency was examined in the photocatalysis degradation of Rhodamine B (RhB) as a cationic dye under the illumination of ultraviolet light. The effect of various parameters, such as the type of light, photocatalyst dose, initial RhB concentration, and pH of the RhB solution, was studied. The results revealed that 90% degradation was achieved within 90 min at a pH of 6.8, 50 mg of a photocatalyst dose, and 10 mg/L of RhB dye under UV irradiation. However, 98% degradation of RhB dye was achieved at a pH of 10 under the same other conditions mentioned above. The kinetic study was performed based on the experimental data of the oxidative photocatalytic degradation of the RhB dye. The zero-order, pseudo-first order, and modified Freundlich kinetic models were applied to accomplish this study. The results showed that the photocatalytic oxidation of RhB dye by the Ag2O@CuO heterojunction photocatalyst followed a pseudo-first order kinetic model, with an apparent rate constant of 0.0429 min-1. Furthermore, the Langmuir-Hinshelwood model was used to investigate the RhB photocatalytic degradation kinetics of RhB at concentrations of 5-10 mg/L. The determined value of the intrinsic photocatalytic reaction rate constant was 0.7184 mg/L.min for the Ag2O@CuO heterojunction photocatalyst. Also, the equilibrium adsorption constant was 0.0767 L/mg for the Ag2O@CuO heterojunction photocatalyst.
Bimetallic oxide; Co-precipitation; Copper oxide; Photocatalysis; Rhodamine B dye; Silver oxide
Copyright (c) 2025 The Author(s). Published by College of Engineering, University of Baghdad. https://creativecommons.org/licenses/by/4.0/
Experimental study of gas-brine capillarity measurement at high temperature and pressure
Understanding capillary pressure profiles during gas-brine coreflooding is essential for analyzing fluid behavior in porous media, particularly in gas reservoirs. Direct measurement of capillary pressure in dynamic displacement experiments relies on evaluating the balance between capillary forces and pressure gradients within the porous structure. In this experimental study three rock samples were taken from a natural gas reservoir located on Australia's Northwest Shelf. Experiments were conducted under simulated reservoir conditions (~ 41.37 MPa and 368.15 K) to investigate the effects of pore size, porosity, and water saturation on the capillary pressure profile. The capillary pressure curves (Samples C1–C3) reveal distinct dynamic behaviors. Samples C1 and C2, which have higher permeability and porosity, exhibit an initial decrease followed by a monotonic rise in capillary pressure until breakthrough. In contrast, Sample C3, characterized by lower permeability and porosity, shows lower brine saturation. However, higher brine saturation would typically be expected in low-porosity samples due to increased grain surface area and smaller pore throats that trap the wetting phase. This unexpected result is attributed to the experiments being conducted under high-pressure and high-temperature conditions. These findings underscore the critical role of pore geometry in governing displacement efficiency and capillary trapping. They also provide valuable quantitative insights for reservoir modeling, particularly in predicting gas recovery under HPHT conditions where capillary forces are significant.
Capillary Pressure; Coreflooding; HPHT; Gas Reservoir
Prediction of cadmium removal efficiency by emulsion liquid membrane using an artificial neural network
This study presented Intelligent Network's proposed methodology for forecasting the effectiveness of cadmium removal from wastewater using emulsion liquid membrane (ELM). The research examined the removal of cadmium from an aqueous solution in the internal phase of water-in-oil emulsions. ELM was composed of kerosene as the membrane phase, Span 80 as the surfactant, di-2-ethylhexyl phosphoric acid (D2EHPA) as the extracting agent, and hydrochloric acid (HCl) as the stripping solution. Experiments were conducted to investigate the effects of five parameters: surfactant concentration, feed-phase agitation speed, internal-to-membrane phase volume ratio, emulsion-to-feed volume ratio, and stripping-phase concentration in the internal phase. More than 97.4% of cadmium can be extracted in less than 15 minutes. This study evaluates the effectiveness of various learning algorithms, including gradient descent (GD), resilient back propagation (RB), gradient descent with momentum (GDM), gradient descent with learning momentum and adaptive rate (GDX), polak-ribiére conjugate gradient (CG), and levenberg marquardt (LM), in predicting the efficiency of cadmium elimination from wastewater using liquid emulsion membrane technology. The researchers developed a neural network model with 8 input neurons, 10 hidden neurons, and 1 output neuron. This feed-forward artificial neural network (ANN) incorporated various back-propagation training algorithms to simulate the cadmium removal process using ELM. The neural network model's predictions closely aligned with results from batch experiments, as demonstrated by a correlation coefficient (R2) of 0.9723 and a Mean Squared Error (MSE) of 0.0041, calculated in MATLAB. In conclusion, the ANN models demonstrated high accuracy and reliability in predicting cadmium removal efficiency, confirming their potential as practical tools for process optimization.
emulsification; surfactant; cadmium removal; emulsion; artificial neural network
Design and evaluation of advanced nanocomposite drilling fluid systems through marl-based lithologies: A study based on outcrop samples from Kurdistan
Swelling is recurring challenges, which can lead to formation damage and compromising the wellbore integrity. Synergizing nanomaterials with their distinctive properties, alongside cost-effective materials, can provide a significant approach in enhancing the treatment of wellbore stability. This study employs a green, simple, and economical approach for the biosynthesis of SiO₂/KCl/Xanthan nanocomposites (NCs), aimed at reducing swelling and improving the rheological and filtration properties of Water-Based Drilling Fluids (WBDFs). The impact of SiO₂/KCl/Xanthan nanocomposite on swelling was assessed, followed by a comprehensive investigation into fluid’s filtration and rheological properties, including apparent viscosity, plastic viscosity, yield point, gel strength, and filter cake thickness. The results confirmed that the green-synthesized NCs effectively reduced clay swelling by approximately 22.2%. Furthermore, they significantly improved the mud’s rheological characteristics, decreasing filter cake thickness and fluid loss by approximately 91.29% and 91.7%, respectively, under HPHT conditions. The findings strongly suggest that SiO₂/KCl/Xanthan NC is an effective additive for mitigating clay swelling, enhancing rheology, and reducing filtration challenges in marl rich formation.
Nanotechnology; Drilling Engineering; Marl-Rich Formation; Swelling, Rheological and Filtration
Kinetic modeling of Dodonaea viscosa decomposition under microwave-assisted pyrolysis: A combined model-fitting and iso conversional approach
This work examines the kinetic behavior of Dodonaea viscosa during microwave-assisted pyrolysis as a means of addressing the limited insight regarding how biomass degradation pathways are affected by non-conventional heating. Thermogravimetric data were analyzed using both model-fitting (Coats–Redfern) and model-free (Friedman and Kissinger–Akahira–Sunose) methods to provide a thorough analysis. Results indicated that a third-order kinetic model appropriately described the general trend of decomposition; in contrast, iso-conversional analyses verified a multi-stage sequence with the activation energy declining during volatile yields and increasing at elevated conversion levels as a result of carbonaceous residue decomposition. These complementary understandings demonstrate that microwave-assisted heating ensures the development of characteristic reaction dynamics rather than those derived from traditional pyrolysis and thus supply mechanistic support for increased energy efficiency. The results not only unify methodology gaps between model-fitting and iso-conversional methodology but also provide useful direction for the optimization of microwave pyrolysis parameters, thus enhancing the sustainable production of lignocellulosic biomass-derived bioenergy.
Microwave-assisted pyrolysis; Dodonaea viscosa; Thermogravimetric analysis (TGA); Kinetic modeling; Isoconversional methods; Activation energy
Implementation of chemical injection with WJSTP in the Gullfaks field attributed to reservoir permeability
The Gullfaks field is a complex field and it’s divided into several formations, which have reservoirs in several stratigraphic layers and fragments of numerous faults. With current technological advancement techniques used in the Gullfaks field, the WJSTP is one of the solution-testing platforms that focuses on treating produced water for re-injection back into the reservoir to increase oil production. The implementation of chemical injection with WJSTP in the Gullfaks field, attributed to reservoir permeability to increase oil production, is the aim of this paper. To attest to the set aimed, a three-dimensional static model of the reservoir is constructed using data provided by NGB Geosciences Consulting LTD. With credit to the Petrel software simulation tool, an in-place volume estimate of 2,748,727,672.95 Bbls of oil and 970,264,150,943.39 SCF of gas was reviewed. Subsequently, a dynamic model is constructed on the foundation of the static model and the specified water injection parameters, and simulated with the use of the Eclipse software. The reduction in permeability of the reservoir's high-permeability zones through chemical injection of WJSTP resulted in 70% oil recovery, representing a 44.99% increase, and 74% gas recovery, representing a 37.9% increase. The sensitivity analysis conducted on oil price, oil production, and investment demonstrates that the viability of the project is highly contingent on the oil price. The findings of this study indicate that chemical injection of WJSTP represents a technically feasible and economically profitable method of enhancing oil production in the Gullfaks field.
Gullfaks field; static and dynamic model; permeability; WJSTP; Petrel; Eclipse; profitability
Field development planning using an active surrogate model and optimization algorithms for a Southern Iraqi oil field
Greenfield development planning is a challenging problem due to the complex objective function and the large number of variables. While stochastic algorithms and data-driven offline surrogate models have been used to locate and control wells, these methods often require a large number of runs or fail to reach an accurate optimal solution. For this reason, the current study aimed to develop a dynamic surrogate model updated after each evaluation, referred to as an active learning model. In this study, deepEnsemble and gaussian process (GP) algorithms were applied as an active alternative model. This approach was compared with optimization algorithms directly coupled with real simulations, where algorithms such as genetic algorithms (GA), particle swarm optimization (PSO), complex matrix adaptation evolution strategy (CMA-ES), and differential evolution (DE) were used for comparison. The deepEnsemble active model outperformed the other approaches, achieving a net present value (NPV) of more than 1 E+10 and 17% recovery factor (RF) for a field in southern Iraq for a production scenario. The algorithm suggested shutting in two existing wells and drilling 23 new wells. The algorithm was also tested using a water injection scenario; a stable pressure, NPV of approximately 1.28 E+10, and 25% RF was achieved by suggesting drilling 39 new wells, 17 of which were injection wells. The approach has proven effective in dealing with complex field development problems with a minimum number of runs.
DeepEnsemble; Optimization; Proxy Model; Well Placement; Field Development
Characterization and kinetic studies of oxidation desulfurization of model diesel fuel in an oscillatory baffled reactor using co-magnetic active oxides over activated carbon catalyst
Oxidative desulfurization (ODS) has attracted interest in the academic and industrial fields to meet new, stringent environmental legislation and produce environmentally friendly fuel. In this work, catalytic oxidative desulfurization of dibenzothiophene (DBT) compounds in diesel fuel is studied using a co-magnetic active oxide over an activated carbon (Fe2O3 + MnO2/AC) catalyst. DBT oxidation reactions are conducted in new oscillatory and non-oscillatory baffled reactors (OBR and NOBR). New central baffles for handling catalyst particles as a fixed bed in the OBR are developed for the first time. ODS process is examined using hydrogen peroxide as oxidant under different operating parameters: temperatures: 30 - 90 °C, oxidation times: 3–12 min, frequency: 0.5 - 2 Hz, and amplitude: 3 -12 mm. The results observed that the highest desulfurization efficiency (98.1 %) is achieved under the best conditions (90 °C, 12 min, 2 Hz, and 12 mm) in OBR. The dramatic DBT oxidation in a short desulfurization time is mainly attributed to the synergistic effect of oscillatory flow and the high activity of the synthesized catalyst. The desulfurization kinetic model is examined under the best conditions. Kinetic results show that ODS reactions follow a first-order model. Also, a low activation energy (3.68 kJ/mol) is determined, which proves rapid DBT oxidation at a lower required energy.
DBT oxidation; Co-active catalyst; Activated carbon; Oscillatory baffled reactor; Kinetic parameters
Enhanced transportation of crude oil from the East Baghdad field using kerosene mixed with silica nanoparticles and the presence of surfactant
This study investigates the enhancement of heavy crude oil transportability from the East Baghdad Oil field through viscosity and density reduction. The proposed approach combined the use of silica (SiO₂) nanoparticles, kerosene, and the anionic surfactant SDBS. Prior to application, the silica nanoparticles were thoroughly characterized using thermogravimetric analysis (TGA), X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (SEM-EDX). These techniques confirmed the particles’ thermal stability, crystalline structure, nanoscale morphology, and elemental composition, validating their suitability for crude oil modification. A nanofluid was formulated with 18 vol% kerosene, 2 wt% SiO₂ nanoparticles, and 10wt% surfactant relative to nanoparticle mass. The mixture was dispersed ultrasonically under controlled thermal and temporal conditions. Optimal performance was achieved at 75 °C and 60 minutes of mixing, reducing viscosity from 58.15 cP to 16.53 cP and increasing API gravity from 19.67 to 28.84. Further enhancement was achieved with increased additive concentrations of 30% vol. kerosene, 3,000 ppm SiO₂, and 300 ppm surfactant, yielding a viscosity of 5.5 cP and an API gravity of 32.67. These results correspond to improvements of 90.5% and 66%, respectively. Control experiments using kerosene alone highlighted the superior efficiency of the ternary system. Given its affordability and availability, kerosene contributes to the practicality of this technique, offering a scalable and economically viable strategy for upgrading heavy crude oil in real-field applications.
Heavy crude oil; East Baghdad field; Reducing viscosity; Density; Nanoparticles; Silica; Kerosene; Surfactant
Comparative evaluation of hydraulic fracturing performance in vertical and horizontal wells using pipesim software
This research paper uses pipesim software to reproduce and evaluate well performance, comparing vertical and horizontal wells using hydraulic fracturing. It examines the impact of key parameters, such as fracture length, width, permeability, and fracture number, on production improvement. In low-permeability reservoirs, simulation studies indicate that horizontal wells often achieve higher production rates than vertical wells, largely due to improved reservoir and fracture connectivity. Productivity in the vertical well increased to 300(stb/d), while in the horizontal well, it increased to over 9,000 (stb/d) after using hydraulic fracturing. The results indicate that fracture width has less of an impact on the performance of vertical wells than horizontal wells, although fracture length and fracture number significantly influence horizontal well productivity. This disparity underscores the need for strategic fracture design and well selection to optimize oil production under changing reservoir conditions. The research paper emphasizes the need to use advanced modeling tools such as PIPESIM to accurately predict well performance and guide decision-making in hydraulic fracturing operations. Tailor-made fracturing techniques based on reservoir properties can significantly enhance continuous production efficiency and extend well life.
Halfaya oil field; hydraulic fracturing; horizontal wells; vertical wells
Enhancing nanofiltration desalination performance using air sparging technique
Concentration polarization is a critical problem for nanofiltration membranes, as it reduces permeate flux and increases operating costs. This study aims to assess the efficacy of air spraying technology as an innovative approach to enhance nanofiltration membrane performance, specifically in water treatment. The methodology focused on conducting comprehensive trials using simulated water and on implementing air-spraying technology at flow rates ranging from 1.5 to 4.5 liters per minute. The membrane's performance was tested under a range of conditions, including varied input concentrations (2,000 to 15,000 ppm), pressures (4 to 6 bar), water flow rates, and temperatures (20 and 32°C). The results showed that adding air efficiently reduces concentration polarization, thereby significantly increasing permeate flux and the effectiveness of sodium chloride rejection. At 2,000 ppm and 6 bar, the most significant flow was 168 liters/h, with a rejection ratio of 90.8%. The highest achievable flux was likewise reached at 32°C, with an excellent rejection ratio of 91.75%. The study, on the other hand, indicated that increasing the feed concentration worsened the permeability flux. This study demonstrates that air-spraying technology is an effective means of improving nanofiltration membrane performance.
Air sparging; Nanofiltration membrane; Permeate flux; Concentration polarization; pressure; Feed concentration; Temperature
Tetracycline removal from aqueous solution through photo-anodic oxidation process using rotating graphite cylinder anode
In the present work, tetracycline (TC) was removed from a simulated wastewater through a new photo-anodic oxidation process with a rotating graphite cylinder anode. The effects of current density, pH, rotation speed, and NaCl addition were evaluated. The results confirmed that increasing the current density results in improving the removal of TC. However, increasing the current density beyond 5 mA/cm2 had little effect on TC removal. Results revealed that TC removal using photoanodic oxidation can be achieved at high performance with an initial pH of 5. Increasing or decreasing pH beyond this value has a negative effect on TC removal. Increasing rotation speed gave better performance for TC removal due to the increase in mass transfer. The addition of NaCl improved the removal efficiency of TC due to the participation of indirect anodic oxidation within the oxidation process. The best conditions were: current density of 5mA/cm2, pH=5, 250 rpm, and the addition of 1 g/L NaCl, in which TC removal of 84% was achieved that claims (103 kWh/m3) as a total electrical energy consumption. In comparison with the anodic oxidation process alone, photo-anodic improved TC removal by an increment of (13.73%), confirming the photo-anodic process can be adopted successfully for treating wastewaters.
Tetracycline; anodic oxidation; photo-oxidation; rotating anode; graphite; wastewaters
Efficient treatment of petroleum refinery wastewater by an induced electro-Fenton process
The induced electrochemical-Fenton (I-EF) process is one of the electrochemical advanced oxidation processes (EAOPs) that has been recently applied to treat various types of wastewaters. In this work, the I-EF process, comprising a graphite/SnO2-Sb2O3 anode, an iron-screen-induced electrode, and an air-diffusion cathode, was used to treat petroleum refinery wastewater. The effects of current density (2-10 mA/cm²), pH (3-7), and the number of screens on the induced electrode (1 and 4) on chemical oxygen demand (COD) removal were investigated. Results showed that increasing pH improved COD removal, whereas increasing current density beyond 3 mA/cm2 reduced it. Increasing the screen number also enhanced the COD removal. The preferred conditions were a current density of 3 mA/cm², pH of 7, and four screens, resulting in a COD removal of 88% within 120 min, which claimed an electrical energy consumption of 0.8575 kWh/m³, confirming the successful application of I-EF in petroleum refinery wastewater treatment under natural pH with minimum sludge generation.
Induced Electro-Fenton; Petroleum refinery wastewater; Fenton reaction; COD removal
Green synthesis of NiO nanoparticles with activated carbon from Ficus carica leaf and extract for malachite green removal
The green synthesis of nanoparticles and activated carbon has attracted researchers' interest due to its rapid, cost-effective, sustainable, and environmentally friendly nature. In this paper, the synthesis of activated carbon (AC) and nickel oxide nanoparticles (NiO-NPs) from Ficus carica leaf and their extracts for the removal of malachite green from aqueous solutions. activated carbon (AC) was synthesized from Ficus carica leaves using a pyro-carbonic acid microwave method. In contrast, nickel oxide nanoparticles were produced using leaf extracts as a reducing and stabilizing agent. The manufactured activated carbon and NiO nanoparticles were characterized by Brunauer-Emmett-Teller analysis, scanning electron microscopy with energy-dispersive X-ray spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The influence of various factors, including malachite green concentration, pH, contact time, and dosages of NiO, AC, and NiO/AC, was examined using Response Surface Methodology (RSM) in Design-Expert (13 Stat-Ease). the optimal parameters for achieving maximum removal efficiency of malachite green dye were determined to be an initial concentration of 150 mg/L, pH of 4, a contact period of 120 minutes, and an adsorbent dosage of 0.25 g/L, resulting in removal efficiencies of 97.9202%, 98.8932%, and 99.9776%, respectively. The equilibrium adsorption data were analyzed using the Langmuir, Freundlich, and pseudo-first- and second-order kinetic models. the results indicated that the Freundlich isotherm and pseudo-second-order kinetic models were the most effective in representing the equilibrium adsorption data.
Ficus carica leaf; green synthesis nanoparticles; activated carbon; malachite green
Optimum design and performance analysis of a gas lift system in the carbonate reservoir of Ahdab oil field
Gas lift is one of the most important artificial lift methods for increasing oil production, as wells often require this method after the reservoir's energy has decreased. In this research, an optimal gas lift system is designed for five horizontal wells in the Ahdab oil field, which suffers from low production. At the same time, water cut in some of these wells reaches 66%, while the productivity index is low in others, which makes the challenges clear, and a deep analysis is needed to find an optimal system. The Pipesim program is used to design the optimal gas lift system, which contains features that facilitate the implementation of the appropriate design and provide the ability to analyze and determine the optimal design values, as well as to detect future production problems. A single system is designed for wells located in the same formation, where an injection pressure of 1750 psi, an injection rate of 1 mmscf/d, and a wellhead pressure of 300 psi are chosen for wells in the Mishrif formation, noting that three valves will be installed in the system. For the wells in the Rumaila formation, an injection pressure of 1950 psi, an injection rate of 1.25 mmscf/d, a wellhead pressure of 475 psi, and four valves were selected for the unloading process. The results proved the design efficiency and that the selected values ​​were optimal, as the increase in production for the five wells was 238%, 146%, 56.6%, 55.9%, and 37.4%.
Ahdab oilfield; Artificial lift; Gas lift, Pipesim; Oil production
Improving the elimination of methyl orange dye by combining electrocoagulation system with the adsorption process by oven-dried alum sludge: adopting different combined systems
Due to their recalcitrant characteristics, Azo dyes such as methyl orange (MO) are extremely poisonous substances, making their removal from textile industry wastewater a major problem. By employing various EC-Adsorption combined system configurations and reusing alum sludge as an adsorbent, the current study seeks to investigate the efficiency of these various systems in removing MO dye. To estimate their benefits and limitations, experiments were carried out utilizing nickel foam (NiF) and aluminum plate (Al plate) as anodes, and stainless-steel mesh (SS mesh) as cathode in the presence of alum sludge as an adsorbent in all systems. The EC-Adsorption combined system with NiF as anode and two SS meshes as cathodes with 10 g/L of alum sludge in the solution, which is referenced as S3, offered 98.968% of MO dye removal efficiency within 30 minutes without the need for prolonged treatment and with very low concentration of leached Ni ions. The BET surface area, pore size, surface morphology, and composition of alum sludge were examined. The utilization of alum sludge in the combined system enhanced the removal of excess Ni ions and reduced its impact in the treated solutions, and moderately enhanced the MO dye removal efficiency. To attain a detailed explanation of the adsorption mechanism, various kinetics and isotherm models were applied. The adsorption of MO dye in the S3 EC-Adsorption system follows the intra-particle diffusion model, and the best-fit isotherm was the Freundlich isotherm.
combined systems; alum sludge; electrocoagulation; Adsorption; kinetic model
Removal of Ni and Cd cations from wastewater using photocatalytic reactions: Review paper
A clean environment and human health depend on removing heavy metal ions from wastewater. Ecosystems and public health are seriously threatened by heavy metal ions, such as nickel (Ni), lead (Pb), cadmium (Cd), vanadium (V), chromium (Cr), and copper (Cu). For example, because of its toxic effects, cadmium is only permitted at 0.005 mg/L in drinking water, while lead has a maximum permissible concentration of 0.015 mg/L. Heavy metal ions have been extracted from various wastewater types using methods such as adsorption, membrane filtration, chemical addition, electrochemical treatment, and photocatalysis. Nevertheless, conventional techniques frequently encounter obstacles like exorbitant operating expenses and restricted effectiveness, with removal rates occasionally falling below 70%. These techniques can also result in hazardous byproducts, which makes wastewater treatment procedures more difficult. Because photocatalysis is so versatile in environmental remediation, it can be used to remove heavy metals. The ability of semiconductor nanostructures based on metal oxides to effectively remove heavy metals from contaminated water has garnered attention recently. For instance, when exposed to particular light wavelengths, zinc oxide (ZnO) and titanium dioxide (TiO2) can remove some heavy metals with up to 95% removal efficiencies. Zeolites have been used increasingly in wastewater treatment over the past 20 years; applications have shown removal capacities of up to 100 mg/g for cadmium and 150 mg/g for lead. This article examines recent developments in using zeolites to extract heavy metals from contaminated solutions. Both traditional and modern wastewater treatment methods are compiled and discussed in this comprehensive analysis, including the application of ZSM-5 zeolites in photocatalytic technology, which can lower operating costs by up to 30% and improve removal efficiencies. Combining zeolites with photocatalytic systems is a viable strategy to raise the efficacy of heavy metal remediation in wastewater treatment.
Cadmium; Heavy metal ions; Nickel; Photocatalyst; Wastewater
Effect of Fe(II) addition by ion exchange and precipitation of different semiconductors on the textural properties of 13X zeolite
This study investigated the textural properties of 13X zeolite, FeX zeolite, TiO2/FeX zeolite, ZnO/FeX zeolite, and TiO2+ZnO/FeX zeolite using nitrogen adsorption-desorption data at consistent low temperatures. The adsorption-desorption isotherm indicated that the studied materials have a type IV mesoporous structure, as defined by the International Union of Pure and Applied Chemistry. The results of nitrogen adsorption data analysis using the Langmuir, Freundlich, and Brunauer-Emmett-Teller models indicated that the data were best described by the Brunauer-Emmett-Teller model. The Barrett, Joyner, and Halenda model was used to analyze the pore size distribution, pore diameter, and average pore volume of the adsorbents. After the ion exchange and loading process, there was a notable decrease in surface area and pore size distribution values, while the reduction in pore volume was minimal. Zeolite 13X showed a larger pore diameter, suggesting that some structural damage or the formation of wider pores within the mesoporous range occurred during the ion exchange steps or modification by the addition of semiconductor oxides. In contrast, the FeX zeolite exhibited a smaller pore size, indicative of a more compact microporous structure. While the modified zeolites—TiO2, ZnO, and TiO2+ZnO—demonstrated a consistent pore structure, suggesting stable mesoporosity with a smaller pore size, this implies that some of the zeolite's pores were blocked or filled with TiO2 and ZnO particles.
Adsorption-Desorption; physisorption isotherms; mesoporous structure; pore size distribution; surface area
A low-cost in-line ozone gas monitor via ultraviolet absorption spectroscopy
A low-cost in-line ozone monitor based on the principle of ultraviolet absorption was built and tested for different ozone for concentrations up to 300 mg h-1 and flow rates up to 5 lpm using air as a feed source. A widely available T5 ultraviolet (UV) tube was used as a UV source and two UV light absorption cells were made to act as reference and measuring cells. The output of the two cells was used to calculate the ozone concentration using Beer-Lambert’s law. To correlate the output readings of the ozone monitor with those obtained using the iodometric titration method, a correction factor of 1.5117 was determined and applied. The results demonstrate a strong linear correlation ≥0.99 between estimated and measured ozone concentration values. Relative errors less than 10% were observed for ozone concentrations ranging from 400 to 5000 ppb, while a relative error up to 16% was reported for concentrations below 400 ppb. The developed monitor offers a cost-effective alternative to expensive ozone monitoring systems for standard applications, with a total construction cost under $100.
ozone monitor; UV-absorption; Beer-Lambert law
Challenges and future directions in photoelectro-Fenton techniques: A comprehensive review of emerging applications and innovations
This comprehensive review examines the fundamental principles and practical applications of heterogeneous electrochemical wastewater treatment utilizing Fenton's reactions. The fundamental equations involved in generating hydroxyl-free radicals in electro-Fenton and photoelectro-Fenton processes have been reviewed. Photoelectro-Fenton processes have been proven to be the most effective methods for mineralizing and degrading pollutants in wastewater. The primary focus is on understanding the limitations of hybrid Fenton processes and proposing practical solutions to address these challenges. Additionally, the study evaluated the significance of electrode configuration development and light penetration enhancement in promoting hydrogen peroxide production and enhancing hydroxyl radical generation. These improvements contribute to the enhanced degradation and mineralization of contaminants in groundwater. A comparative analysis of electrode materials, novel reactor configurations, and operating conditions demonstrates the relationship between preparation methods and treatment efficiency. Research gaps for improving the photoelectro-Fenton process are identified, with suggestions for future work. Studies have shown that internal light irradiation leads to higher removal efficiency compared to external lighting systems with the same light source power. The most important recommendations were utilizing multi-electrode stacked reactors to reduce energy consumption, enhancing current efficiency, the shape of the electrodes also plays a vital role in increasing light exposure on the photoanode surfaces, and conducting long-term experiments with various contaminants to demonstrate the reactor's stability, efficiency, and efficacy in treating industrial wastewater.
Electrode arrangements; Novel reactors; Fenton hybrid; Doping methods; Fenton's challenges
Photocatalytic degradation of methylene blue by robust visible-light-driven polyvinylidene fluoride membranes incorporating Ag2O@CRA photocatalyst: Kinetics analysis and cost assessment
The kinetic study of the visible-light-driven photocatalytic degradation of methylene blue (MB) dye by the Ag₂O@CRA heterojunction photocatalyst and robust polyvinylidene fluoride membranes incorporating Ag₂O@CRA heterojunction photocatalyst (PVDF/Ag₂O@CRA) was investigated. This study involves a comparison of the outcomes of the kinetic study performed based on the experimental data of the oxidative photocatalytic degradation of the MB dye. The zero-order, pseudo-first-order, and modified Freundlich kinetic models were applied to accomplish this study. The results showed that the photocatalytic oxidation of the MB dye by the Ag2O@CRA photocatalyst followed the pseudo-first-order kinetic model, and the apparent rate constant (k1) value was 0.1231 min-1. The photocatalytic oxidation of the MB dye by the modified PVDF membrane with 0.3 wt.% Ag2O@CRA photocatalyst followed the pseudo-first-order kinetic model, and the apparent rate constant (k1) value was 0.0196 min-1. Also, the Langmuir-Hinshelwood model was used to model the MB photocatalytic degradation kinetics by the Ag2O@CRA photocatalyst for 10-40 mg/L inlet MB concentrations. Likewise, the Langmuir-Hinshelwood model was used to model the kinetics of the MB photocatalytic degradation by the PVDF membrane with 0.3 wt.% Ag₂O@CRA photocatalyst for 5-20 mg/L inlet MB concentrations. It was found that the intrinsic photocatalysis reaction rate constant (kr) was 0.8286 mg/L.min for the Ag₂O@CRA heterojunction photocatalyst and 0.209 mg/L.min for the PVDF/Ag₂O@CRA photocatalytic membrane. Also, it was found that the equilibrium adsorption constant (Kad.) was 0.3245 L/mg for the Ag₂O@CRA heterojunction photocatalyst and 0.218 L/mg for the PVDF/Ag₂O@CRA photocatalytic membrane. The manufacturing cost for the Ag₂O@CRA photocatalyst and PVDF/Ag₂O@CRA photocatalytic membrane was estimated to be $2.45/10 g and $78/m², respectively.
Kinetics, oxidation; heterojunction photocatalyst; photocatalytic membrane; polyvinylidene fluoride; methylene blue
Modification of Y-zeolite mesoporosity by ultrasonic-assisted technique as active catalysts for catalytic cracking of VGO
In this study, Pristine Y zeolite (CBV 400) of Si/Al )2.5( was treated to produce modified mesoporous zeolites. The process involved the aid of post-synthesis sequential dealumination in its conventional mode and ultrasonic-assisted desilication techniques. Both ethylene-diaminetetraacetic acid (EDTA) and oxalic acid (OX) were tested as chelating reagents in the dealumination step for 1, 3, and 6 h. The dealuminated samples of zeolite were treated sophisticatedly with sodium hydroxide NaOH in a water bath sonication at a frequency of 20 Hz and 65 ºC for different times of 5 and 15 min. Dealumination of the original zeolite by OX acid for 3h and desilication of the acid-treated sample with NaOH solution for 15 min has improved the mesoporosity by around 120% higher than the parent sample of Vmeso=0.08 m3/g. The modified sample has a mesopore volume (Vmeso) of 0.2 m3/g and an external surface area (Sexternal) of 89 m2/g. The resulting mesoporous zeolite was examined for stability measurements via thermal treatment at 550 ºC for 3h, which reveals high stability. Parent and modified zeolite were tested as heterogeneous catalysts for the catalytic cracking reaction with VGO and 1g catalyst load with different temperatures (from 400 to 420 °C) and a reaction time of 480 minutes. The reaction was carried out using a batch reaction system, and a higher yield of gasoline (about 44.44 vol%) was obtained using the modified zeolite (UDSY15-OX3) at 420 °C reaction temperature, as opposed to the direct use of the non-modified catalyst, which gives out only 18.4 vol% gasoline yield. Thus, commercializing the OX-NaOH pathway with the assistance of ultrasonic energy can decrease the treatment duration and energy consumption, producing a thermally stable mesoporous material to catalyze the cracking reactions of heavy oils.
Mesopore volume; Y zeolite; dealumination; Ultrasonic-assisted desilication; Modified Zeolite; VGO; catalytic cracking
CO2 hydrate formation enhancement via bare and hybrid silica nanoparticles effect: Implications for hydrate-based CO2 sequestration
Carbon dioxide geological storage gives tremendous promise for mitigating anthropogenic carbon emissions. CO2 hydrate has been given rising attention due to its potential in carbon geo-sequestration projects. The effect of silica nanoparticles (SiNPs) on the kinetics of CO2 hydrate formation was systematically studied at 3.5 MPa and 280 K. Pure (bare) and surface-modified (hybrid) SiNPs were separately characterized and used in this study. The effect of bare and hybrid SiNPs concentrations on the induction time of CO2 hydrate formation was investigated. A high-pressure, high-temperature stainless steel vessel was used as a hydrate reactor, and pressure-temperature data were continuously recorded to follow the hydrate formation process. Results revealed that the SiNPs significantly impact the kinetics of CO2 hydrate formation. The increase of Hybrid SiNPs concentration (>0.03 wt% hybrid SiNPs), significantly reduces the induction time and thus accelerates the rapid formation of CO2 hydrate. In contrast, bare SiNPs showed a lower effect on CO2 hydrate formation. Further, the increase of bare SiNPs (e.g., >0.07 wt% bare SiNPs) can tend to eliminate the effect of NPs on induction time. Thus, surface-modified SINPs can significantly enhance CO2 hydrate formation when formulated correctly.
CO2 hydrates; carbon storage; silica nanoparticles; nanofluids; formation kinetics
Dynamic modeling for optimal subsurface reservoir fluid mapping in Mature oil fields
Development of a mature oil reservoir blocks strategy in optimizing hydrocarbon production from mature oil fields. Using dynamic modeling techniques together with subsurface interpretations that were based on sharply adjacent well data, the study has presented new development well placements. Production data studies, pressure surveys, and detailed subsurface studies will be integrated to improve the understanding of the reservoir behavior to predict reservoir performance. The key findings indicate high increments in oil production on account of the implementation of new development wells. The current research provides not only empirical evidence supporting the efficacy of strategic drilling but also lends a structured workflow applicable for similar mature oil fields, thus providing practical means for increasing production and improvement in field life. Opportunities that deliver high value yet have limited associated risks and costs are typically characterized in general by short payout periods and reinvestment of savings. Unlocking residual potential from low-productivity or shut-in wells, maximizing asset value, and using information to drive decisions on optimizing is an asset development strategy. These strategies can only be effectively implemented if inter-disciplinary teams work together to ensure that data is comprehensively analyzed and all solutions are formulated in line with these analyses. This work discusses the efficiency of developing non non-drained oil reservoir blocks strategy in optimizing hydrocarbon production from mature oil fields. Using dynamic modeling techniques together with subsurface interpretations that were based on sharply adjacent well data, the study has presented new development well placements. The study of the Abu Rudeis oil field has laid the foundation for long-term optimization, integrating production data, pressure surveys, and geological studies into a comprehensive reservoir management strategy. The interdisciplinary approach ensured well-informed and targeted decisions, resulting in enhanced hydrocarbon recovery and improved field performance. Results from the three-dimensional grid that captured heterogeneity in the reservoir, the assignment of reservoir properties like porosity and permeability, and fluids distribution helped to leverage data-driven strategies and advanced technology, the field's sustainability and efficiency have been significantly improved, providing a strong foundation for future optimization efforts.
Modeling; mature field; well placement; fluid saturation; reservoir management; subsurface studies; Abu Redeis Field
Studying the chromatographic separation of caffeine, theophylline, and theobromine
Theobromine, theophylline, and caffeine retention times in a C18 HPLC column (stationary phase) were investigated as a function of mobile phase flow rate, mobile phase composition, and column temperature. When the mobile phase flow rate increased from 0.1 to 1 mL/min and the methanol concentration increased from 5 to 30%, the retention time and peak width of these three compounds were found to be reduced. While there was a small influence of increasing the mobile phase flow rate on the resolution, decreasing the methanol concentration in the mobile phase considerably reduced the resolution. In addition, the mobile phase flow rate and composition were determined to have a more significant impact than the column temperature. According to the findings, theobromine, theophylline, and caffeine were most effectively separated by liquid chromatography at a flow rate of 0.5 mL/min with a mobile phase methanol concentration of 15%.
HPLC; Mobile phase; Stationary phase; Retention time; Resolution
Tracking metabolic gases in an airlift bioreactor for enhanced microalgae cultivation
Airlift bioreactors have been classified as a promising technology for microalgae cultivation. Several improvements have contributed to increasing the mixing efficiency and production. However, some challenges are still facing this biological process. One challenge is the efficient dissolution and delivery of carbon dioxide to microalgae cells, which remains a limiting factor in the biological processes. On the other hand, sparging the gas in large quantities may lead to gas loss if microorganisms do not completely consume it. In this study, microalgae were cultivated in two stages and compared: the first stage of injecting 5 ml of carbon solution into a conical flask and the second stage of sparging 5 liters/hour in an airlift bioreactor with increasing sparging time this is done by sparging carbon dioxide gas at the same flow rate from day to day, but increasing the sparging time by 30 seconds, starting with sparging the gas for one minute until reaching 7 minutes. The results showed that the airlift bioreactor gives a higher growth rate of microalgae than that produced in a conical flask. The maximum biomass concentration reached 5 g/L in the airlift bioreactor culture with a maximum specific growth rate of 0.324 day−1, while it reached 1.0799 g/L in the conical flask culture with a specific growth rate of 0.187 day−1. This result shows the importance of the airlift bioreactor in microalgae cultivation. Also, the internal composition of the biomass was found that the airlift bioreactor was the best, as the amount of lipids, carbohydrates and protein was (2.06, 1.43, and 18.03 g per 30 g of dry biomass), respectively, while the internal composition of the control cultivation was (0.005386, 0.00428, 0.05754 and g/L), respectively. The volumetric mass transfer coefficient showed that when the sparging time increases, the oxygen gas transfer coefficient increases until it reaches 1.0397 s−1. The pH value was also maintained around 7, which is the appropriate value for increasing the growth rate.
Mass transfer; airlift bioreactor; microalgae; sparging; carbon dioxide
Analysis of production characteristics and engineering measures for deep coalbed methane wells in the Ordos Basin
Given the significant differences in gas accumulation modes, coal reservoir characteristics, and gas preservation conditions for ultra-deep coalbed methane (vertical depth > 3000 m, measured depth > 5000 m), their production characteristics, flowback patterns, and flow phase classifications also vary greatly. Additionally, there are limitations in the production technologies applicable to deep reservoirs. To explore the relationship between the production characteristics of deep coalbed methane and medium-shallow coalbed methane, as well as to investigate suitable technologies for deep coalbed methane, this paper uses Well Q1 as an example and conducts research and analysis based on reservoir engineering theory. It is believed that in the vertical section of Well Q1(The depth is generally less than 3000m), the flow pattern transitions from bubbly flow to slug flow in the early stage, and with reduced water production, it is predicted to transition from transitional flow to annular flow in the later stage. In the inclined section (The depth is generally between 3000 and 4000m), slug flow predominates most of the time, while in the horizontal section (The depth is generally greater than 4000m), the flow evolves from elongated bubble flow to slug flow in the early stage, from elongated bubble flow to stratified smooth flow in the middle stage, and remains in the stratified smooth flow zone in the later stage. Furthermore, it is proposed that the insertion depth of Well Q1 should be correlated with the well deviation angle, gas production rate, and water production rate. From the perspective of gas-water ratio optimisation and energy efficiency, there should be an optimal timing for tubing insertion.
Deep coalbed methane; Production regime; Production mode; Engineering measures; Flowback analysis; Flow pattern prediction
Geomechanical properties evaluation of Mauddud formation based on experimental measurements and well log data
Mauddud formation is one of the most prominent formations in Northeastern Iraq due to its significant hydrocarbon reserves, making accurate geomechanical characterization essential for safe drilling operations and informed development planning. This study constructs a calibrated post-drill one dimensional mechanical earth model (1D-MEM) for selected wells, levering Techlog software to integrate rock mechanical data, image logs, multi-arm caliper measurements, conventional well logs, drilling reports, and core analyses. The methodology provides a detailed workflow for estimating geomechanical properties from log and image analysis to model calibration. Validation of the 1-D MEM performed through cross-comparison with direct measurements, ensuring the reliability of the predicted stress and strength profile. Laboratory and field data including pore pressure measurements using DST method, destructive and non-destructive mechanical tests, scanning electron microscopy (SEM), thin section test (TS), X-ray diffraction test (XRD), and energy-dispersive X-ray spectroscopy (EDS) have all been used for analyzation and calibration process. These datasets enhance the MEM parameters and support the derivation of empirical correlation specific to the Mauddud Formation. Derived correlations include compressional-shear slowness velocity, slowness velocity- bulk density, compression slowness-unconfined compressive strength (UCS), and the Young's modulus to UCS correlation. Results show that mineralogical composition particularly porosity and calcite content have a dominant influence on formation strength with high porosity, low calcite intervals resulting in the lowest UCS values.
Rock Mechanical Properties Evaluation; Experimental Rock Evaluation; UCS; X-Ray Diffraction; Scanning Electron Microscopy
Research and application of gas lift technology in bedrock gas reservoirs -A case study of Jianbei gas reservoir
The Jianbei gas reservoir, situated in the Altun Mountains of the Qaidam Basin, is a typical bedrock gas reservoir. Since its commissioning, the gas wells have generally encountered water breakthrough, leading to a significant drop in production. To address this issue, a pressurised gas lift process was implemented to drain water and boost production. While most wells exhibited positive production increases, some showed little to no change in productivity post-treatment. Therefore, it is imperative to investigate the reasons for these discrepancies and adjust/upgrade the original plan accordingly. Through comprehensive analysis from various perspectives, including fluid accumulation issues, the gas lift process itself, and wellbore structure, it was identified that the primary factors limiting the effectiveness of gas lift in the Jianbei gas reservoir are severe fluid accumulation in the wellbore, poor adaptability of the gas lift process in certain wells, inappropriate tubing size, and severe formation damage. To tackle these issues, the gas lift plan for the Jianbei gas reservoir was upgraded and optimised. Relevant parameters were redesigned based on tubing diameter optimization principles and gas lift characteristic curves, aiming to maximize the stimulation effect of gas lift. This approach effectively resolves the existing technical challenges and provides a solid scientific foundation and technical support for future gas reservoir management and development, ensuring optimal operation of the gas wells.
Bedrock; Gas lift; Restrictive factors; Gas recovery by water drainage
Determination of controlling fouling mechanism using the Hermia models and estimation of the manufacturing costs of the modified polyvinylidene fluoride-based ultrafiltration membranes
Membrane fouling is the main problem that limits the use of membrane technology. This work focuses on using the Hermia models to determine the controlling fouling mechanisms, including intermediate pore blocking, complete pore blocking, standard pore blocking, and cake formation. Also, it investigates the estimation of the manufacturing costs, which included the costs of preparation materials and energy consumed during the preparation and casting processes of the polyvinylidene fluoride/polyethylene glycol (PVDF/PEG) and PVDF/PEG-tin oxide nanoparticles (PVDF/PEG-SnO2 NPs) membranes. The results of Hermia’s models were applied on the first, third, and fifth cycles of the rhodamine B dye solution filtration processes. Depending on linear fitting parameters, the membrane fouling occurred in all fouling mechanism types simultaneously. However, the predominating fouling mechanism was cake formation followed by intermediate pore blocking. Analysis of the parameters of the fouling models validated that the irreversible fouling exceeded the reversible fouling when the correlation factor (R2) value was higher than 0.95, which explains the continuous reduction of the permeate flux for both studied membranes. The estimated cost of the locally manufactured PVDF-based membranes did not surpass 80 $/m2 of the membrane. Also, the locally fabricated flat sheet ultrafiltration membranes are cheaper than other pristine PVDF membranes manufactured by Guochukeji Technology (Xiamen) Company.
PVDF membrane; PEG, Tin oxide (SnO2); Fouling mechanisms; Hermia models; Economic estimation