Browsing by Author "SELMANI Abderrahmane"

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    Modeling a zero-gap asymmetric electrolyzer: a fundamental approach to overcome the geometric limits
    (National Higher School of Technology and Engineering-Annaba, 2025) SELMANI Abderrahmane; KERBOUA Kaouther (Encadrant)
    The widespread use of reverse osmosis (RO) for seawater desalination has intensified the issue of brine disposal, raising environmental concerns due to its high salinity and chemical load. This study investigates a sustainable valorization route by coupling industrial field data from the UTE Desaladora plant in Skikda, Algeria, with a numerical model of asymmetric zero-gap electrolysis for the recovery of valuable products, notably hydrogen (H₂) and hydroxide ions (OH⁻). A MATLAB-based simulation tool was developed to assess the performance of the electrolyzer under various operational parameters, including voltage, temperature, gas bubble accumulation, Faradaic efficiency, and hydroxide capture factor effects. Polarization curve, has demonstrated that anode activation significantly enhanced the system's efficiency, reducing internal resistance of nearly 70% and increasing performance by up to 65%. The performance assessment showed strong agreement between simulation and experimental results in hydrogen production while greater deviations were observed in current evolution over tome, mainly due to gas bubble accumulation and simplified assumptions in the model. The parametric study revealed that temperature increase reduced cathodic resistance by 46% and increased H₂ output by more than 60%. Similarly, bubble coverage beyond 30% drastically increased ohmic losses, while a hydroxide capture factor above 0.9 severely hindered conductivity and gas production. Discrepancies between simulation and experimental data highlighted the impact of real-world phenomena such as bubble coverage and side reactions, emphasizing the need for more comprehensive and dynamic modeling.
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    Solar electrolysis as an integrated pilot-scale continuous process coupled with reverse osmosis with energy recovery perspectives
    (National Higher School of Technology and Engineering-Annaba, 2025) SELMANI Abderrahmane; KERBOUA Kaouther (Encadrant)
    Reverse osmosis (RO) is a widely adopted desalination method, but its large-scale use raises environmental concerns due to the discharge of concentrated brine into marine ecosystems, reducing dissolved oxygen and harming aquatic biodiversity. This study proposes a valorization pathway using asymmetric zero-gap electrolysis to convert brine into value-added products such as hydrogen (H₂), sodium hydroxide (NaOH), and hypochlorite ions (ClO⁻). The system employs a Nafion Perl 500 diaphragm with low-cost electrodes namely carbon foam (anode) and nickel foam (cathode). A parametric study exploring supply potential, temperature, feed flow rate, and water type effect identified optimal performance using RO water as the electrolyte at 2.3 2.5 V, achieving over 96% Faradaic efficiency. Anode activation using a nickel-based catalyst reduced internal resistance by 80% at 2.3 V and 25% at 6 V, enhancing H₂ and OH⁻ generation kinetics. Synthetic brine provided more stable and efficient results compared to industrial brine, which exhibited greater complexity. Photovoltaic (PV) integration demonstrated the potential for decentralized, off-grid green hydrogen and chemical co-production. However, further investigation is required to elucidate the coupled effects of ion transport, reaction kinetics, and gas evolution in zero-gap architectures.