Iraqi Journal of Chemical and Petroleum Engineering

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.

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.

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.

The petroleum industry faces a significant problem in enhanced oil recovery (EOR) from carbonate reservoirs because of their mostly oil-wet character, which restricts hydrocarbon extraction. To better understand how surfactant-polymer techniques can enhance oil recovery, this study investigates the effectiveness of polyvinyl alcohol (PVA) as a stand-alone agent and the function of ionically modified smart water on carbonate properties. The study focuses on its effect on critical parameters essential for effective oil displacement and recovery, such as wettability alteration, interfacial tension, and surface tension (ST) using different brines (smart water). The ability of the polymer PVA to lower interfacial and surface tension was investigated. PVA decreased surface tension in brine to 44 mN/m, although smart water solutions showed more noteworthy outcomes. When PVA was added to smart water with a 1:1 Mg²⁺/SO4²⁻ ratio, the lowest ST (29 mN/m) and IFT (11.8 mN/m) values were observed. The hydrophilic properties of PVA and its ionic interaction with Mg²⁺ were key factors in encouraging water adsorption on the surface of the carbonate rock. The contact angle was getting closer to zero, indicating that this interaction resulted in a full transition to a water-wet condition. Enhancing the oil displacement process in carbonate reservoirs—generally refractory to recovery—requires this complete transition to water-wet conditions. This full shift to water-wet conditions is vital for enhancing the oil displacement process in carbonate reservoirs, which are typically resistant to recovery due to their oil-wet surfaces.

Chitosan polymer is an essential supporting material for the synthesis of metallic nanoparticles (MNPs) because of its exceptional capping and stabilizing qualities, biocompatibility, biodegradability, eco-friendliness, polycationicity, and non-toxicity. To produce copper-based chitosan nanoparticles, choose a suitable chemical procedure hydrothermal method. Each approach offers advantages in terms of homogeneity, morphology, and particle size. This study has produced, described, and examined the bacteriological characteristics of metal nanoparticles based on chitosan, including copper nanoparticles (CS-Cu NPs). Chitosan-based metal nanoparticles have been created using the solution casting technique. The generated nanoparticles were characterized using FTIR, AFM, UV, ZP, and SEM examination. The TEM image illustrates that the materials created are nanomaterials, ranging in size from 1 to 100 nm. The CS-CuNPs, displaying a stable brick-red hue, showed an absorption peak at 214 nm, indicative of monodisperse nanoparticle formation and surface plasmon resonance. X-ray diffraction confirmed the face-centered cubic structure with peaks at 36.78°, 43.38°, 50.56°, and 74.26°, and an average particle size by AFM to 62.45 nm. FTIR analysis showed interactions between chitosan and copper, particularly around 3370 –3226 cm⁻¹, 1633 cm⁻¹, and 680 cm⁻¹ and.The MCF7 cell line demonstrated the strongest anti-human breast cancer cell line properties of the nanocomposite when compared to the aforementioned cell lines. The aforementioned results suggest that the nanocomposite could be used to treat various forms of human breast cancer. Breast cancer had increased nanoparticle sensitivity. At a concentration of 25 μL/mL, Chi-Cu NPs demonstrated excellent cytotoxicity and anticancer activity, making them suitable for use as an anticancer agent.

This work prepared new composite (CuO/NaOH/CW) and compared with another composite (HNO3/NaOH/CW) from cotton waste, sodium hydroxide, copper sulphate and nitric acid for the treatment of refinery wastewater. Dry weight analysis confirmed the attachment of 29 and 32 % NPs in the composites of copper oxide and nitric acid, and their observed slow-release behavior contributed to enhanced stability. The accessory of copper oxide to the cotton waste surface fibrils and their deep infiltration into the matrix were obviously established by characterization analysis. The composite material was evaluated for its adsorption and photodegradation capabilities for organic removal from refinery wastewater (RWW). Remarkably, the synthesized composites exhibited impressive waste cotton activities against organic pollutants, achieving reduction rates of 89.2%, 78.4%, and 55.4% for CuO/NaOH/CW, HNO3/NaOH/CW, and NaOH/CW, respectively. The cotton waste based CuO composites demonstrated non-toxicity and catalytic behavior under UV light exposure, offering insights for potential applications in organic pollutant removal and environmental remediation.

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.

This paper explores the sorption potential of red Iraqi kaolin (IRK) for methylene blue (MB) elimination by sorption process. Batch tests were examined the impact of agitation time, IRK dose, pH, shaking speed, and MB concentration. The results demonstrated that IRK effectively removes MB, achieving a maximum elimination efficiency of 91.976% within 0.05 g/100 mL, 120 min, 7, 200 rpm and 50 mg/L for IRK dosage, contact duration, pH, shaking speed, and concentration of MB, respectively. The kinetic analysis showed that the sorption mechanism was fitted a pseudo 2nd order, therefore chemisorption is the primary mechanism. Intra-particle diffusion investigation demonstrated that the sorption mechanism is influenced by many concurrent procedures, particularly surface complexation and ion exchange. In addition, the Freundlich isotherm model fits the experiment's measurement higher than the Langmuir model, showing the heterogeneous surface features of IRK and the maximum sorption capacity (qmax) equal to 587.08 mg/g. The current investigation demonstrates the possibility of IRK as an effective and inexpensive sorbent for wastewater treatment applications, opening up opportunities for further research into sorbent regeneration and real-world wastewater situations.

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.

The petroleum industry's operations often involve substantial water usage, resulting in vast quantities of contaminated water, with a volume of the polluted water body estimated as about half the quantity of oil utilized in the refinement process. This wastewater contains various substances that are harmful to the health and environment, including hydrocarbons, heavy metals, and other toxic chemicals. This research aims to explore photocatalytic synthesis of zinc oxide nanoparticles to treat oil refinery wastewater. The effectiveness of this approach will be assessed by measuring the rate of Chemical Oxygen Demand (COD) reduction while identifying the best conditions to achieve the best performance and maximizing energy efficiency. Various operational conditions that drive the influence on the wastewater treatment process were investigated, including pH of 3, 5, 7, and 9, flow rate of 0.25, 0.5, 0.75, and 1.0 l/min, and the amount of the photocatalyst used per unit area (20, 40, 60, 80, 100 g/m2). Under optimum conditions, the photocatalytic method was applied with the following parameters: a COD of 1278 mg/l, a pH level of 7, a catalyst density of 80 g/m2, an effluent flow of 0.25 l/min, an irradiation power of 65 W, and an airflow of 100 cubic centimeters per minute. After 120 minutes, the COD reduction efficiency reached 76%, requiring energy consumption of 173.4 kW.hr/m3.

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.

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.

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.

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.

In this study, oxidative desulfurization of dibenzothiophene (DBT) with H2O2 as an oxidant was studied, whereas the catalyst used was zirconium oxide supported on Activated carbon (AC). Zirconium oxide (ZrO2) was impregnated over prepared activated carbon (AC) and characterized by various techniques such as XRD, FTIR, BET, SEM, and EDX. This composite was used as a heterogeneous catalyst for oxidation desulfurization of simulated oil. The results of this study showed that ZrO2/AC composite exhibited significant catalytic activity and stability, effectively lowering sulfur content under mild conditions. Factors such as reaction temperature (30, 40, 50, 60°C), time (5, 10, 15,20,30,60, 80 100 min), catalyst dose (0.3, 0.5, 0.7, 0.9 g) and initial concentration of dibenzothiophene (DBT) (20,40, 60, 80, 100, 200, 300 ppm) was used to achieved maximum efficiency. 10 ml of H2O2 /100 ml of simulated oil was used as an oxidizing agent. It was found that an increase in all the above variables led to an increase in desulfurization efficiency, except for an increase in initial DBT concentration, which led to a decrease in removal efficiency. The maximum removal efficiency of sulfur content was 92.22%, which was achieved at 60 °C and 0.9g of composite /100 ml of simulated oil at equilibrium time 100 min and 100ppm initial concentration of DBT. Finally, the reaction kinetics matched the pseudo-second order rate model, with an activation energy of 36.665 KJ/mol.

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.