New Approach to Solve Some Problems in Undergraduate Education of Chemical Engineering Students

The present short paper is an attempt in the direction of understanding the learning problems of undergraduate students. Sample of chemical engineering students was selected to perform a simple exam test. The test was divided into four steps. Closed book - individual student, Closed book - cooperative students, Open book - cooperative students, and Exam completion steps. Questionnaire was carried out to obtain the research results. It was found that a large percentage of the students are not studying carefully, the studying method was shallow and depend only on reading ready printed lectures. The results compared with previous exam results. Current test improved the performance of students. The novelty of present work represented by applying a new teaching method in colleges of engineering in Iraq. This short paper also proved that the methods of teaching not restricted to social and humanity studies. paper is an attempt in the direction of understanding the learning problems of undergraduate students. Sample of chemical engineering students was selected to perform a simple exam test. The test was divided into four steps. Closed book - individual student, Closed book - cooperative students, Open book - cooperative students, and Exam completion steps. Questionnaire was carried out to obtain the research results. It was found that a large percentage of the students are not studying carefully, the studying method was shallow and depend only on reading ready printed lectures. The results compared with previous exam results. Current test improved the performance of students. The novelty of present work represented by applying a new teaching method in colleges of engineering in Iraq. This short paper also proved that the methods of teaching not restricted to social and humanity studies

Evaluating the techno-economic potential of large-scale green hydrogen production via solar, wind and hybrid energy systems utilising PEM and alkaline electrolysers

The study evaluates the potential of solar, wind, and hybrid PV/WT renewable energy systems for green hydrogen production in four Iraqi cities. Through a comparative analysis of six distinct scenarios involving the deployment of 60 MWp solar panels, 30 MWp wind turbines, and 45 MWp hybrid PV/WT systems, the research aims to ascertain the most energy-efficient and cost-effective strategy for hydrogen generation. This evaluation is aligned with the operational capacities of two types of water electrolyzers: Alkaline (AWE) and proton exchange membrane (PEM), each with a 17.5 MWp capacity. Employing the HOMER Pro software for system simulation and optimization, and considering a project timeline from 2022 to 2042, the study identifies Anbar City as the prime location for green hydrogen production, highlighting solar PV panels as the most economical option with the lowest levelized cost of energy at US $4.5/MWh. The analysis further demonstrates that hydrogen production costs are US$1.98/kg for AWE electrolyzers and US $2.72/kg for PEM electrolyzers, with net present costs of US$26.31 million and US $35.91 million, respectively. Moreover, the annual hydrogen output is estimated at 1.11 million kg for AWE and 1.19 million kg for PEM electrolyzers. These insights significantly contribute to the strategic planning and development of Iraqi green hydrogen sector, offering a valuable framework for policymakers and stakeholders invested in sustainable energy transitions.<br/

Optimization studies of expired mouthwash drugs on the corrosion of aluminum 7475 in 1 M hydrochloric acid:Gravimetrical, electrochemical, morphological and theoretical investigations

The aim of the present work is to study the corrosion inhibition of Al 7475 alloy by an expired mouthwash drug (EMWD) in a 1 M HCl solution. The corrosion rate was optimized by the Doehlert experimental design at various temperatures, concentrations of inhibitor, and rotational velocity. The corrosion behavior was investigated by mass loss, Tafel potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) techniques. SEM, MOMT, XRD, FT-IR spectrum, and drop wettability measurement were used in characterizations of EMWD and surface morphology. Optimum conditions for corrosion control of EMWD on aluminum were 44.12 °C, 141.71 mL/L of EMWD per liter of acid, and 234.89 rpm. Maximum corrosion inhibition efficiency was 84.717% at higher levels of temperature and inhibitor concentration. It is observed that EMWD follows the Langmuir Adsorption Isotherm with negative values of ΔGadso, proposing a stable spontaneous inhibition process. The inhibitor efficiency increased as the inhibitor concentration increased. Moreover, increasing the solution temperature and rotational velocity had an adverse influence on inhibitor efficiency. The results of mass loss were in good agreement with potentiodynamic polarization and EIS. Polarization diagrams revealed that the inhibitor acts as a mixed-type inhibitor. It could be concluded that response surface Doehlert design (RSDD) was adequately applicable in the optimization of corrosion inhibition process variables and that EMWD sufficiently inhibited the corrosion of the aluminum at the studied conditions. Simulation of the EMWD molecules adsorption on the metal surface by quantum chemical theoretical studies was a powerful tool for supporting experimental outcomes.</p

Mass transfer influence on the corrosion inhibition of N80 steel in 1 M H₂SO₄ by green corrosion inhibitor using MATLAB

The corrosion process of steel alloys in acidic environments is typically considered to be governed by charge transfer (activation) control. Nonetheless, in aerated solutions, mass transfer can affect the electrochemical measurements. This study examines the corrosion inhibition of N80 steel in 1 M sulfuric acid using okra leaf extract (OLE), utilizing electrochemical polarization techniques at various concentrations of the inhibitor and different temperatures. The outcomes of electrochemical data of current densities and overpotentials were fitted to a high-order polynomial equation and the Maclaurin series formula. The coefficients of the high-order polynomial equation were evaluated using a non-linear regression method, which is in turn used in the Maclaurin series formula. A series of complex equations were derived, incorporating a factor (β) to account for the impact of mass transfer on the activation-controlled corrosion process. A complex equation set of β-models was processed using MATLAB computer programming. In addition, a β-model was correlated to a mass transfer correction factor (γ) and polarization resistance (Rp). β-values ranged from 0.005 to 0.916 (average 0.198), which indicates the presence of a mass transfer effect in addition to the activation effect (mixed control corrosion mechanism). Conversely, the polarization resistance (Rp) increased with higher inhibitor concentrations and decreased as the temperature rose.</p

Zeta Potential Optimization of Nano Chitason/SrCl2/MgO Suspension for Electrophoretic Deposition Using Taguchi Method

The stability of Electro Phoretic Deposition (EPD) suspensions containing nanoparticles relies on the impact of Zeta Potential (ZP or ). This property ensures that the nanoparticles have a consistent and stable surface charge, resulting in a uniform and stable coating. This research has been conducted as an experimental study and used the Taguchi method to design experiment optimization of the Zeta potential values, which were obtained by preparing nine suspensions. The study aimed to determine the optimal ZP value for the EPD suspension created with three materials mixed: nanochitason, Chitason/SrCl2/MgO, and a constant value of hydroxyapatite (HA) with consideration of the pH effect. After conducting an analysis, it was found that the suspension's Zeta Potential is negatively charged below a pH value of 8.22. Between 8.22 and 9.7, the ZP has a positive charge. The suspension's isoelectric point (IEP) is 8.22, with a high correlation coefficient indicating the model's reliability in predicting responses. The analysis showed that SrCl2 has the most significant impact on the suspension's ZP, followed by Chitason (CH), with MgO having the least impact. The results demonstrate the effectiveness of this analysis in determining the optimum ZP value for various solutions prepared from different biomaterial particle

Okra leaves extract as green corrosion inhibitor for steel in sulfuric acid: Gravimetric, electrochemical, and surface morphological investigations

Utilizing plant extracts as an alternative source for corrosion inhibitors holds significant promise in minimizing the risk of corrosion. In this study, an okra leaf extract (OLE) was employed as a corrosion inhibitor for N80 steel in 1.0 M H2SO4. The corrosion rate was assessed concerning temperature (30, 40, 50, and 60 °C) and inhibitor concentrations (blank, 25, 50, 75, and 100 ml/l) through weight loss and electrochemical polarization techniques. The results indicated that OLE functions as a mixed-type corrosion inhibitor, with corrosion rates increasing with temperature and decreasing with inhibitor concentration. The maximum corrosion inhibition efficiency reached 96 % at 30 °C and 100 ml/l. Adsorption studies revealed that OLE physically adsorbed onto the mild steel surface, following the Langmuir adsorption isotherm. Gravimetrical and electrochemical techniques were confirmed by FTIR and UV measurements, which showed the presence of a protective layer on the metal surface. Optical microscopy, AFM, and SEM images demonstrated the formation of a protective layer on the metal surface. Thermogravimetric analysis (TGA) highlighted the thermal stability exhibited by inhibitor molecules, which showed that OLE was thermally stable up to 85 °C

Performance of polyacrylamide as drag reduction polymer of crude petroleum flow

The influence of polyacrylamide (PAM) as drag reducing polymer on flow of Iraqi crude oil in pipe lines was investigated in the present work. The effect additive concentration, pipe diameter, solution flow rate and the presence of radius elbows on the percentage of drag reduction (%Dr) and the amount of flow increases (%FI) were the variables of study. Maximum drag reduction was 40.64% which was obtained with 50 ppm of PAM polymer flowing in straight pipes of 0.0508 m I.D. The dimensional analysis was used for grouping the significant quantities into dimensionless group to reduce the number of variables. The results showed good agreement between the observed drag reduction percent values and the predicted ones with high value of correlation coefficient

Sunlight assisted photocatalytic mineralization of organic pollutants over rGO impregnated TiO2 nanocomposite: Theoretical and experimental study

In this work, the spectrum and electrochemical characterization of prepared rGO incorporated TiO2 photocatalyst was carried out and it activity was investigated under direct sunlight for the degradation of Congo Red (CR) and tricloroacetic acid pollutant. The chemical structural, morphology and spectral properties of catalysts were characterized utilizing X-ray diffraction, Raman spectroscopy, X-photoelectron microscopy, transmission electron microscopy (TEM), and photoluminescence spectroscopy (PL) respectively. The TiO2 catalyst with different loading rGO from 1% to 10%, showed higher photoactivity as compared to pure TiO2. Efforts were made to connect the improvement activity of rGO loaded TiO2 with spectrum and electrochemical properties. At lower incorporating (1%rGO), the improvement photodegradation was assign to the excited trap of electrons, while the electron trap and synergic effect between rGO and TiO2 played the main role in higher loading. The electrochemical properties of rGO loading TiO2 were characterized by electrochemical impedance spectroscopy (EIS). The determination of intermediates and investigation of the released anions appeared the supporting of superoxide and hydroxyl radicals in degradation process. This study showed that 2,4-dichorophenoxy acetic acid degrades at a higher rate than congo red. The photodegradation mechanism of dyes under sunlight was studied by LC-Mass and the scavenger effect. Under sunlight, the photodegradation of congo red and tricloroacetic acid using pure and rGO incorporated TiO2 was adjusted at normal conditions with excellent efficiency

Experimental Modeling of Inhibition's Mechanism of Cupronickel Alloy by DETA and EDA into Acid Corrosive Media

The corrosion inhibition of cupronickel alloy in 5% hydrochloric acid (HCl) was investigated in the absence and presence of diethylenetriamine (DETA) and ethylenediamine (EDA) as organic corrosion inhibitors. The effects of inhibitor concentration and temperature were investigated using mass loss method. The results obtained show that EDA act as an anticorrosion material for cupronickel alloy in hydrochloric acid with a maximum performance of 66.7%, while DETA was a poor inhibitor with maximum efficiency of 34.7%. The inhibition performance was found to increase with increase in inhibitor concentration and decrease with increase in temperature. The adsorption of both inhibitors on surface of metal was found to obey Freundlich isotherm. The values of the free energy of adsorption were below − 20 kJ/mol that is indicative of physisorption (physical adsorption). The proposed mechanism of the inhibition process suggests an adsorption of amine groups on metal surface. Mathematical models were also suggested to correlate the dissolution rate data as a function of temperature and inhibitor concentration. High correlation coefficients were obtained between experimental and predicted data. The mean value of residual between the experimental and predicted data was 0.457.</p

The inhibition effect of 1, 3-diazole glyoxaline on corrosion of API 5L X52 pipeline steel in oilfield produced water under sweet corrosive conditions

Corrosion induced by aqueous environments containing carbon dioxide (CO2) is a well-documented issue in the oil and gas industries, particularly affecting transportation via steel pipelines. Operational conditions during transportation, including temperature, flow rate, and solution chemistry, significantly influence the corrosion inhibition mechanism. In this study, the corrosion inhibition behavior of API 5L X52 steel in a 3.5 wt% NaCl brine solution saturated with carbon dioxide was investigated using 1, 3-diazole glyoxaline (DG) as an organic inhibitor. Both gravimetric and electrochemical methods were employed to assess corrosion rates and inhibitor efficiency across various temperatures, inhibitor concentrations, and rotational speeds. The outcomes showed that inhibition efficiency increased with inhibitor concentration and temperature. From weight loss measurements, the maximum inhibition efficiency was 98.58 % at 3 × 10−4 M of DG and 60 °C. The polarization investigations showed a reduction in the anodic and cathodic curves in the presence of the inhibitor. This suggested a mixed-type inhibition mechanism. The electrochemical impedance spectroscopy results showed an improvement in charge transfer resistance due to the formation of a protective layer on the metal surface. In addition, AFM, SEM, contact angle, hardness, and roughness measurements proved the enhancement in surface morphology due to the presence of DG