Vol 7 - Special issue CIER

Entropy: Thermodynamics – Energy – Environment – Economy

List of Articles

Le Centre National de la Promotion Scientifique et de l’Innovation (CNPSI) représente un nouveau lien entre les chercheurs académiques et les professionnels, d’une part, et les institutions internationales, d’autre part, tout en couvrant un large éventail de disciplines liées à la recherche et à l’innovation. Le CNPSI est une organisation qui promeut la recherche scientifique et l’innovation dans le monde, sans aucune discrimination. Il agit comme un pont entre les jeunes et les professionnels expérimentés dans les domaines universitaire, industriel et des startups, à travers des événements et des activités scientifiques de pointe, ainsi que des activités socioculturelles.

This study investigates the optimization of the light naphta isomerization process at the Algiers Refinery, with a focus on the operational efficiency of the Deisohexanizer (DIH) column. Isomerization is a critical refinery process that upgrades low-octane linear alkanes into high-octane branched isomers, thereby enhancing the Research Octane Number (RON) of the gasoline pool. The research methodology employed Aspen HYSYS software to conduct rigorous steady state modeling and performance analysis of the unit. To quantify the added value of the fractionation section, a baseline simulation was first established for a once-through configuration that excluded the DIH. Subsequently, a comprehensive simulation integrated the Deisohexanizer into the process flow to evaluate its impact on the global system efficiency and product quality. The study focused on the sensitivity analysis of key operating parameters, including reflux ratios, feed tray locations, and reboiler duties. These adjustments aimed to maximize the separation of low-octane normal hexane (nC6) from high-octane dimethylbutanes, thereby optimizing recycling cycles and minimizing energy consumption. The final results identify several optimal operating points and provide a set of technical recommendations proposed to Sonatrach. These suggestions aim to enhance the RON of the final isomerate while maintaining cost-effective energy profiles within the Algiers refinery’s current infrastructure.

The increasing penetration of renewable energy sources (RES) significantly modifies power system dynamics by reducing inertia and amplifying nonlinear interactions. Conventional eigenvalue-based small-signal stability methods capture linearized behavior but fail to reveal hidden nonlinear oscillatory components emerging under renewable-rich conditions. This paper investigates the oscillatory stability of the Tunisian power grid projected for 2030 under a peak-load scenario with 35% RES penetration. Using a detailed nonlinear PSAT model, Classical Linear Modal Analysis (LMA) is combined with Koopman Modal Analysis (KMA), a data-driven operator-based approach extracting spatiotemporal dynamic structures from simulation data. Results show that LMA identifies the dominant inter-area mode near 0.8 Hz, while KMA reveals additional weakly damped nonlinear modes within the critical [0.7–1 Hz] band. Koopman mode shapes highlight a dominant North–[Centre + South] oscillation driven by the 400 kV transmission backbone, with time-domain reconstructions confirming long decay times. The study proposes targeted measures including PSS improvement, transmission reinforcement, PMU-based wide-area monitoring, and advanced control strategies. KMA is demonstrated as a powerful complement to classical modal analysis for future renewable-dominated grids.

Orange peel waste is inсrеasingly aсknоwlеdgеd аs аn effесtivе mаterial fоr anаerоbic digestiоn, which can generatе biоenergy suсh аs biоhydrоgеn and biоmethаnе. Hоwеver, its use as а renewablе enеrgy sоurcе is still limited оn a glоbаl lеvеl. Therefore, this study is to assess thе capaсity fоr biоgas prоductiоn frоm оrangе pееl wastе, collected during the ripening period of the Thomson variety (December–February 2024).The elemental composition and structure of the orange peels biomass were assessed through CHNS-O and SEM-EDX analyses. To evaluate the efficiency of hydrolysis and mass transfer, two particle size fractions were selected: D1 (63–250 μm) and D2 (250–500 μm). Various parameters were monitored during the anaerobic digestion experiments, including pH, total sugar concentration and biogas volume. It has been found that the orange peels contain 34.66 % carbon, 44.88 % oxygen, 0.40 % nitrogen, and 7.35 % hydrogen. The high oxygen content reveals a predominance of oxygenated organic compounds, particularly carbohydrates, which are available to anaerobic microorganisms and promote rapid biodegradation. The cumulative biogas produced is about 955.5 mL and 232 mL for D1 and D2, respectively. Thereby improving microbial accessibility, diffusion, and the stages of anaerobic digestion. Furthermore, the Geompertz modified model has been employed to follow the kinetics of biogas production.

Over the past three decades, humanity has achieved considerable progress in terms of technological innovations. This transformation has reshaped the urban landscape, offering territorial decision-makers variety of tools to design new public policies and innovative strategies and benefit from these new solutions. Emerging from the opportunities created by the use of Information and Communication Technologies, the concept of the "Smart City" appeared in the early 21st century, with the primary objective of ensuring the sustainable and efficient management of resources while improving the quality of urban life. To achieve these goals, the concept relies on six essential pillars: smart governance, smart citizens, smart mobility, smart economy, smart environment, and smart living. This paper indeed, focuses on smart living, particularly the Smart Home, and explores how new technologies are perceived by the residents of Casablanca, given that the city has been engaged since 2015 in its smartization project known as Casablanca Smart City. The main objective of this study is to examine the perception of home automation, adopting a mixed-method approach based on the exploratory sequential design and taking into account the personal, social, and environmental challenges that influence the way individuals perceive these complex systems.

This study examines the relationship between foreign direct investment (FDI), institutional quality, and environmental degradation in 50 developing countries from 1996 to 2024. Using a panel ARDL model, it distinguishes between short- and long-run effects on CO₂ emissions. The results strongly support the Pollution Haven Hypothesis (PHH). FDI, trade openness, and economic growth significantly increase emissions in the long run. In contrast, corruption control plays a key mitigating role. In the short run, the impact of FDI is limited, but causality tests reveal a one-way effect from FDI to emissions. This highlights the structural influence of foreign investment on environmental outcomes. Countries with weak governance are particularly vulnerable. Foreign capital often flows into pollution-intensive sectors. Strengthening institutions and promoting green FDI are essential for sustainable development.