Browsing by Author "Haddad, Ahmed"

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    The effect of inhibiting molybdate used in anodizing-conversion treatment to improve corrosion protection of AA2030 aluminum alloy in different steps
    (Springer, 2022) Benmohamed, Manel; Benmounah, Abdelbaki; Haddad, Ahmed; Yahi, Sarah
    In this article, different treatment baths for corrosion protection of 2030 aluminum alloy in addition to replacing the hexavalent chromium due to the European recom- mendation were employed. This work is divided into three steps of treatment: first, anodization using molybdate inhibitor without and with phosphoric acid and, then, pre-oxidation with sodium hydroxide. In the last step, we studied the influence of conversion coating with the combination of sodium molybdate and fluoride on the anodic layer formed on aluminum alloy 2030. In order to characterize the formed lay- ers, we use microstructural characterization (SEM, AFM, and nano-indentation), which allows highlighting the surface condition as well as the morphological distribution, and electrochemical techniques such as potentiodynamic polarization and electro- chemical impedance spectroscopy which shows that the anodization treatment of the aluminum alloy with phosphoric acid and sodium molybdate offered better corrosion resistance. This resistance increased with the use of pre-oxidation and then reached a maximum value of 99.8% efficiency with the addition of the molybdate conversion coating which causes an increase in the double layer and gave an alternative possibility of chromium VI
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    Efficient biodiesel production from recycled cooking oil using a NaOH/CoFe2O4 magnetic nano-catalyst: synthesis, characterization, and process enhancement for sustainability
    (Elsevier, 2024) Bousba, Dalila; Sobhi, Chafia; Zouaoui, Emna; Rouibah, Karima; Boublia, Abir; Ferkous, Hana; Haddad, Ahmed; Gouasmia, Abir; Avramova, Ivalina; Mohammed, Zighed; Pârvulescu, Vasile I.; Yadav, Krishna Kumar
    This research introduces an environmentally sustainable approach to biodiesel production, utilizing waste cooking oil (WCO) as a renewable feedstock. The focal point of this study is the synthesis and characterization of NaOH/CoFe2O4 magnetic nanoparticles, employed as an efficient catalyst for the transesterification reaction between WCO and methanol. Comprehensive analysis, including X-ray diffraction, Fourier transform infrared spectroscopy, scanning electronic microscopy, magnetometry, temperature-programmed carbon dioxide and ammonia desorption, and X-ray photoelectron spectroscopy reveals nanoparticles with remarkable catalytic properties. The transesterification process catalyzed by NaOH/CoFe2O4 yields biodiesel at an impressive rate of 98.71%, complying with ASTM standards. Kinetic and thermodynamic evaluations elucidate reaction mechanisms, and density functional theory (DFT) calculations provide insights into the catalytic process. The magnetic catalyst's reusability enhances sustainability, making it a promising solution for large-scale biodiesel production, and lays the foundation for future catalyst optimization.
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    Experimental Approach to Monitoring the Degradation Status of Pipelines Transporting Hydrocarbons
    (2021) Yahi, Sarah; Bensmail, Aicha; Haddad, Ahmed; Benmohamed, Manel
    Improve the reliability of the gas and oil transportation process is a primary objective of the pipeline designers because it interests the safety of the goods and the people, the availability and the performance of pipelines as well as the economy of the hydrocarbon transport. Corrosion is a present phenomenon that occurs inside and outside of buried pipes, causing the pipeline to be pierced, leading to gas and oil leaks and causes consequences of the major economic losses. In this context, our study focused on the corrosion monitoring of metals used in the transport of hydrocarbons by two approaches based on electrochemical techniques. Monitoring the evolution of the corrosion potential using an elaborated reference instead of a commercial reference electrode, and by electrochemical impedance spectroscopy (EIS) coupled with the gravimetric method. The obtained results showed the efficiency of our approach for the realization of a corrosion sensor intended for the monitoring of corrosion in pipelines.
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    The impact of orbital motion of drill pipe on pressure drop of non-newtonian fluids in eccentric annulus
    (Penerbit Akademia Baru, 2020) Ferroudji, Hicham; Hadjadj, Ahmed; Azizur Rahman, Mohammad; Hassan, Ibrahim; NtowOfei, Titus; Haddad, Ahmed
    For all drilling operation method used to explore a well, the hydraulics program design associated to the well must be carried out carefully. A wrong estimation of pressure drop of the drilling fluid in the annular space can induce several problems, like: stuck pipe, lost circulation and insufficient hole cleaning. ANSYS Fluent 18.2code based on the finite volume method (FVM) is employed to evaluate the orbital motion impact ofdrill pipe on frictional pressure drop of non-Newtonian fluids (Ostwald-de Waele and Herschel-Bulkley models) flowing in laminar and turbulent regimes where the inner cylinder (drill pipe) makes an orbital motion around the centre of the outer cylinder (casing) and pure rotation around its own axis. Moreover, impact of the eccentricity on frictional pressure drop is discussed. Numerical results exhibit that as the Reynolds number increases, effect of the orbital motion speed of the inner cylinder becomes more severe on frictional pressure drop of the Ostwald-de Waele fluid for laminar regime. However, after a certain speed, frictional pressure drop begins to decrease. In addition, increase of the eccentricity induces a decrease of frictional pressure drop of the Ostwald-de Waele fluid in which this effect is more pronounced when the inner cylinder makes orbital motion for both laminar and turbulent regimes
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    A novel methodology for monitoring low-temperature corrosion caused by hygroscopic salts using linear polarization resistance
    (Elsevier, 2024) Yahi, Sarah; Bensmaili, Aicha; Lehmusto, Juho; Hupa, Leena; Haddad, Ahmed; Benmohamed, Manel; Vainio, Emil
    A new methodology for monitoring low-temperature corrosion caused by hygroscopic salts was developed and tested with ZnCl2. First, deliquescence and efflorescence points of ZnCl2 were determined by electrochemical impedance spectroscopy and chronoamperometry measurements in the range of 10–35 vol % H2O. Then, low-temperature corrosion was monitored using a probe that combines linear polarization resistance and mass loss measurements. Suitable potential and scan rate for the linear polarization resistance measurements were experimentally determined. The feasibility of the probe was tested by monitoring the corrosiveness of ZnCl2 on P235GH steel under different temperatures (100–180 °C) and water vapor concentrations (15–35 vol %). With the developed corrosion probe, corrosion caused by hygroscopic salts during changes in testing conditions can be monitored and evaluated.
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    Numerical study of parameters affecting pressure drop of power-law fluid in horizontal annulus for laminar and turbulent flows
    (Springer, 2019) Ferroudji, Hicham; Hadjadj, Ahmed; Haddad, Ahmed; Ofei, Titus Ntow
    Efficient hydraulics program of oil and gas wells has a crucial role for the optimization of drilling process. In the present paper, a numerical study of power-law fluid flow through concentric (E = 0.0) and eccentric annulus (E = 0.3, E = 0.6 and E = 0.9) was performed for both laminar and turbulent flow regimes utilizing a finite volume method. The effects of inner pipe rotation, flow behavior index and diameter ratio on the pressure drop were studied; furthermore, the appearance and development of secondary flow as well as its impact on the pressure drop gradient were evaluated. Results indicated that the increment of the inner pipe rotation from 0 to 400 rpm is found to decrease pressure drop gradient for laminar flow in concentric annulus while a negligible effect is observed for turbulent flow. The beginning of secondary flow formation in the wide region part of the eccentric annulus (E = 0.6) induces an increase of 9% and a slight increase in pressure drop gradient for laminar and turbulent flow, respectively. On the other hand, the variation of the flow behavior index and diameter ratio from low to high values caused a dramatic increase in the pressure drop. Streamlines in the annulus showed that the secondary flow is mainly induced by eccentricity of the inner pipe where both high values of diameter ratio and low values of flow behavior index tend to prevent the secondary flow to appear
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    Pipelines corrosion due to the electromagnetic pollution caused by the high voltage power lines
    (2016) Ouadah, M'hamed; Touhami, Omar; Ibtiouen, R.; Bouzida, Ahcene; Bouyegh, Saida; Allou, Djilali; Haddad, Ahmed