Publications Internationales
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Item Fuel-air ratio effect on hydrogen-methane flames in a high pressure burner for gas turbines(Publishing House of the Romanian Academy, 2024) Ouali, SofianeThis numerical simulation studied the effect of H2-CH4 flame equivalence ratio on turbulent premixed combustion at 50%-50% concentration (by volume). The equivalence ratio was varied from 0.45 to 1.0 in 0.5 increments for 126 kW operating power, matching a 3.3 bar inlet reactant pressure. Tests utilized a gas turbine combustor. The thermal field, flow field, and pollutant emissions (NOx and CO) underwent rigorous analysis. The modelling framework applied steady Reynolds-Averaged Navier-Stokes (RANS) equations coupled to a probability density function (PDF) approach for turbulence-chemistry interactions and a NOx formation model. Results showed increasing equivalence ratio from 0.45 to 1.0 elevated temperature approximately 900 K, significantly promoting NOx up to 1600 ppm and CO beyond 1900 ppm. However, equivalence ratio changes minimally impacted the overall flow field, maintaining stabilized flames. These findings provide new insight on thermochemical effects and flame stability in gas turbine (G.T) combustors across a range of equivalence ratios relevant for clean, high-pressure H2-CH4 combustion. The combined RANS-PDF methodology enables predictive simulation of turbulence, kinetics, emissions, and flame stability to guide optimal fuel-air ratio selection and low-emission combustor design.Item Semiconducting and electrochemical properties of the spinel FeCo2O4 synthetized by co-precipitation. Application to H2 production under visible light(Elsevier, 2023) Bouakaz, H.; Abbas, Moussa; Benallal, S.; Brahimi, R.; Trari, M.FeCo2O4 elaborated by co-precipitation was characterized photo-electrochemically for the first time in order to assess its performance for the hydrogen production. The X-ray diffraction revealed a single phase crystallizing in the spinel structure with a lattice constant of 8.1075 Å and a crystallite size of 35 nm. The UV–Visible diffuse reflectance of the black product exhibits an absorption above 650 nm and a direct optical transition at 1.53 eV was determined, assigned to the crystal field splitting of Co3+: 3d orbital hexa-coordinated. The transport properties indicated semi-conducting properties of FeCo2O4, the positive thermo-power (S300k = 666 μV K−1) demonstrated that holes are majority charge carriers. The Electrochemical Impedance Spectroscopy (EIS) realized in Na2SO4 (0.1 M) electrolyte showed two semicircles at high and intermediate frequencies, characteristic of the charge transfer and grain boundaries respectively. The first diameter (1249 Ω cm2) decreases under visible light down to 742 Ω cm2, thus supporting the semiconducting behavior and no inhibiting effect is observed due to the appearance of the photo-effect. The inverse of the square of the capacitance as a function of the potential (C−2 – E) exhibits a line, negatively slopped, characteristic of p-type behavior with a hole concentration of 21.9 × 1020 cm−3. The conduction band (−0.76 VSCE), made up of Co3+: 3d orbital is more cathodic than the H2-level leading to a spontaneous H2 evolution under visible irradiation (29 mW cm−2) with a liberation rate of 0.58 μmol H2/h−1/g. FeCo2O4 an showed excellent chemical stability after its reuse for the H2 production, as evidenced by X-ray diffractionItem Investigation of natural gas enrichment with high hydrogen participation in dual fuel diesel engine(Elsevier, 2021) Benbellil, Messaoud Abdelalli; Lounici, Mohand Said; Loubar, Khaled; Tazerout, MohandThis study explores the impact of natural gas (NG) enrichment with high H2 concentrations (20, 30, 40 and 50 by v %) on combustion characteristics, engine performance, exhaust emissions and knock in a compression ignition engine running in dual fuel (DF) mode. Results indicated that H2 addition to NG contributes to enhance gaseous fuel combustion that corresponds to an increased heat release rate (HRR) during the premixed phase of gaseous fuel that also causes an increase in the pressure peak, particularly at high loads. The maximum pressure peak and HRR correspond to 50% H2 addition. The combustion duration is shortened for all H2 mixtures. Regarding engine performance, an important benefit in terms of brake thermal efficiency is noted for all H2 blends; it increases with increasing enrichment rate and reaches approximately 16% increase for the 50% H2 mixture relative to pure NG case. Moreover, enriching NG with H2 is an effective solution for reducing unburned hydrocarbons and carbon monoxide at moderate to high engine loads. However, for NOx emissions, the addition of H2 to NG is only attractive at low and moderate loads. In addition, over 80% engine load, NG enrichment with H2 generates knock, which rapidly reaches high intensities.Item Hydrogen production via methane dry reforming process over CoAl and CoMgAl-Hydrotalcite derived catalysts(IOP Publishing, 2021) Abdelsadek, Zoulikha; Chaudhari, P.; Holgado, J. P.; Bali, F.; Halliche, D.; Cherifi, O.; Gonzalez-Cortes, S.; Masset, P. J.Co0.67Al0.31 and Co0.14Mg0.54Al0.31 hydrotalcite based catalysts were prepared by a co-precipitation method at a fixed pH=11, exhibiting a suitable hydrotalcite structure to be used as a catalyst in the reaction of the dry reforming of methane (DRM). Calcination at 450 C provides the best conditions to prepare the most adapted structure and morphology to be later used in the DRM reaction. The samples were characterised by XRD, FTIR, SEM and it was shown that they exhibit a specific surface in the 30-70 g/cm2 and a crystallite size of approximately 20 nm. The results of the TPR analysis showed clearly that CoAl-HT has better catalytic performances than CoMgAl-HT. This result can be explained by the presence of the Co0 for the catalyst CoAl-HTc-R and the total absence in the sample CoMgAl-HTc-R. The solid CoMgAl-HTc-R requires high reduction temperature compared to CoAl-HTc-R due to the strong CoO-MgO interactionsItem Wind flow simulation and characteristics prediction using WAsP software for energy planning over the region of Hassi R’mel(Taylor and Francis, 2021) Meziane, Fares; Chellali, Farouk; Mohammedi, Kamal; Nouicer, Ilyes; Kabouche, NourdineIn this study, we analyzed the wind potential of Hassi R’mel (Algeria) under the Wind Atlas Analysis and Application Program (WAsP) environment, using data measurements at a height of 10 m provided by the National Office of Meteorology (NOM) over the period of 14 years (2003–2017). The results are used as input for predicting wind characteristics (speed and direction) for four other sites covering the studied region where the measurement stations are not available. The pre-feasibility study of large-scale energy and hydrogen production focuses on four sites, namely Telghemt, Delaa, Bouzbier, and Bellil. Two different wind turbine models, Bonus B54 and Nordex N100 with a rated power of 1000 kW and 2500 kW, respectively, were selected. The study pointed out that the region of Hassi R’mel has an important wind potential with an annual mean wind speed of 6.73 m/sec and power density of 365 W/m2 at 10 m. The maximum of energy and hydrogen produced occurs for the site of Hassi R’mel with 12.41 GWh/yr, and 177.37 tons H2/yr, with minimal costs of 5.5 c$/kWh, and 18.42 $/kg H2 respectively using Nordex N100 wind turbine at 100 m. Similarly for the site of Bellil where the maximum of energy and hydrogen production of 5.395 GWh/yr, and 77.08 tons H2/yr were obtained with minimal costs of 5.06 c$/kWh, and 17.12 $/kg H2 respectively using Bonus B54 wind turbine at 60 m. Therefore, the high rate of carbon dioxide (CO2) emissions avoided by N100 was 5428.2 tons CO2/kWh for Hassi R’mel, and 2359.2 tons CO2/kWh for Bellil using the B54 wind turbineItem Effect of natural gas enrichment with hydrogen on combustion characteristics of a dual fuel diesel engine(Elsevier, 2019) Ouchikh, Sarah; Lounici, Mohand Said; Tarabet, Lyes; Loubar, K.; Tazerout, MohandItem A wind energy conversion system for hydrogen production by water electrolysis in the region of Hassi R'mel (Algeria)(Elsevier, 2016) Meziane, Farouk; Khellaf, A.; Chellali, F.; Mohammedi, K.Item Hydrogen supplemented natural gas effect on a DI diesel engine operating under dual fuel mode with a biodiesel pilot fuel(Elsevier, 2017) Tarabet, L.; Lounici, M. S.; Loubar, K.; Khiari, K.; Bouguessa, R.; Tazerout, M.Item Experimental investigation on NG dual fuel engine improvement by hydrogen enrichment(Elsevier, 2014) Lounici, Mohand Said; Boussadi, Asma; Loubar, Khaled; Tazerout, MohandItem The effect of hydrogen adsorption on the properties of undoped and Cu-doped ZnO(101¯0) surfaces : a first-principles study(Elsevier, 2016) Lahmer, Mohammed Ali