Iranian Research Organization for Science and Technology (IROST)Hydrogen, Fuel Cell & Energy Storage2980-85372320150801Optimization of the preparation procedure of Ni/Al2O3 catalyst for steam reforming of n-butane13914922010.22104/ijhfc.2015.220ENDavoodSaydiFaculty of Chemistry and Chemical Engineering, Malek Ashtar University of Technology, Lavizan, P.O. Box 15875-1774, Tehran, IranMahmoudZiaratimalek ashtar universityNahidKhandanDepartment of Chemical Technologies, Iranian Research Organization for Science & Technology (IROST), P.O. Box 3353111, Tehran, Iran0000-0002-2563-1744AmirAliZaherianDepartment of Chemical and Petroleum Engineering, Sharif University of Technology, Azadi Ave., P.O. Box 11365-9465, Tehran, IranJournal Article20151117Performance of Ni/Al2O3 catalysts (10 wt.% Ni) in steam reforming of n-butane was investigated in terms of n-butane conversion, selectivity to hydrogen and hydrogen yield. The process was carried out in a fixed-bed tubular reactor at 650 °C and atmospheric pressure. The volumetric flow rates of n-butane and steam were 0.1 mL/min and 0.6 mL/min, respectively. The catalysts were prepared by precipitation-sedimentation method at different precipitation, drying and calcination temperatures as well as precursor types. Synthesized catalysts were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and BET analyses. It was found that Ni- Nitrate as the precursor was more favorable than the other. Mathematical predictive formulas were generated for responses by Design Expert software. Also, the optimum condition of the catalyst preparation was obtained by using the response surface methodology (RSM). Ultimately, it was concluded that the overall optimum condition were: Tprecipitation= 30°C, Tdrying= 115°C, Tcalcination= 700°C .https://hfe.irost.ir/article_220_ec8ce6abb3e952a85b8551ba726a1227.pdfIranian Research Organization for Science and Technology (IROST)Hydrogen, Fuel Cell & Energy Storage2980-85372320151222Preparation of Pd composite membrane via organic-inorganic activation method in electroless plating technique15115819510.22104/ijhfc.2015.195ENSonaJamshidiNanostructure Material Research Center (NMRC), Sahand University of Technology, P.O. Box 51335-1996, Sahand New Town, Tabriz, IranZahraKouzegarNanostructure Material Research Center (NMRC), Sahand University of Technology, P.O. Box 51335-1996, Sahand New Town, Tabriz, IranAli AkbarBabaluoNanostructure Materials Research Center (NMRC)0000-0002-6985-4149MohmmadHaghigiReactor and Catalysis Research Center (RCRC), Sahand University of Technology, P.O. Box 51335-1996, Sahand New Town, Tabriz, IranJournal Article20151020A palladium composite membrane was prepared via electroless plating technique using organic-inorganic method during activation process. The ceramic support surface was modified by two TiO2-boehmite and one γ-alumina layers to avoid Pd penetration in support pores. Thin and defect-free Pd composite membrane was obtained by creating a relative smoothness on the ceramic support and using Pd nanoparticles in the activated layer. The resulting membrane showed an infinite selectivity for H2/Ar with H2 flux in the range of 0.005-0.035 mol/m2s depending on operating conditions. The hydrogen flux was linearly proportional to the pressure difference across the membrane at different temperatures and then the pressure exponent n was very close to 1. According to linear relationship of Arrhenius plot, the activation energy Ea of Pd membrane was calculated to be 22.54 kJ/mol. H2 permeance kept over 0.023 mol/m2s and the separation factor of H2/Ar over infinite at 773 K for 240 h, confirming high potential of the prepared membrane in H2 purification at high temperatures.https://hfe.irost.ir/article_195_0336dcbab05b9d5ad24f4333c7658a0e.pdfIranian Research Organization for Science and Technology (IROST)Hydrogen, Fuel Cell & Energy Storage2980-85372320150801Modeling and Optimization of non - isothermal two- phase flow in the cathode gas diffusion layer of PEM fuel cell15916821810.22104/ijhfc.2015.218ENHassanHassanzadehBirjand University faculty memberSeyed HadiGolkarMS studentJournal Article20151031In this paper, a non-isothermal two-phase flow in the cathode gas diffusion layer (GDL) of PEM fuel cell is modeled. The governing equations including energy, mass and momentum conservation equations are solved by numerical methods. Also, the optimal values of the effective parameters such as the electrodes porosity, gas diffusion layer (GDL) thickness and inlet relative humidity are calculated using the optimization algorithms. Optimization is done by considering the fuel cell voltage as the objective function. The results show that by increasing the relative humidity of the air, the rate of evaporation in cathode GDL and temperature distribution across the fuel cell decreases. Among the different methods of optimization, the best method for two phase flow is Simulated Annealing algorithm. Optimum porosity of the electrodes, GDL thickness and relative humidity are obtained 0.44, 0.24 mm and 99%, respectively. The fuel cell power density at optimum condition increased 6% compared to the base condition.https://hfe.irost.ir/article_218_e96ed478dab8595a7dbda4cbcbee168f.pdfIranian Research Organization for Science and Technology (IROST)Hydrogen, Fuel Cell & Energy Storage2980-85372320160222Density Functional Studies on Crystal Structure and electronic properties of Potassium Alanate as a candidate for Hydrogen storage16917921110.22104/ijhfc.2016.211ENSamiraAdimiRenewable Energies, Magnetism and Nanotechnology Research Laboratory; Department of Physics, Ferdowsi University of MashhadHadiArabiRenewable Energies, Magnetism and Nanotechnology Research Laboratory; Department of Physics, Ferdowsi University of MashhadShaban RezaGhorbaniRenewable Energies, Magnetism and Nanotechnology Research Laboratory; Department of Physics, Ferdowsi University of MashhadFaizPourarianDepartment of Materials Science and Engineering,. Carnegie Mellon University, Pittsburgh, Pa USAJournal Article20151111Potassium Alanate is one of the goal candidates for hydrogen storage during past decades. In this report, initially the Density Functional Theory was applied to simulate the electronic and structural characteristic of the experimentally known KAlH4 complex hydride. The relaxation of unit cell parameters and atomic positions was performed until the total residual force reduced less than 0.001ev per unit cell. The final deduced cell parameters of this orthorhombic structure were a=8.834, b=5.763, c=7.328A˚. Calculations were carried out by using Projected Augmented Plane wave method via QUANTUM ESPRESSO Package. In the next step, the Density of States calculations together with band structure results, showed that our data coincide with a non-magnetic KAlH4 insulator with a band gap of 5.1ev. In order to investigate the nature of chemical bonds in the crystal structure, the charge density distribution in (100),(010),(001),(110) planes, along with Born Effective charge and Löwdin population was used. The results show the transition of a partial charge from K+ cation to [AlH4]- subunit which leads to an ionic bond.https://hfe.irost.ir/article_211_eb163727917cbba1eea208541a643e74.pdfIranian Research Organization for Science and Technology (IROST)Hydrogen, Fuel Cell & Energy Storage2980-85372320160202Numerical analysis of reactant transport in the novel tubular polymer electrolyte membrane fuel cells18119621210.22104/ijhfc.2016.212ENAkbarMohammadi-AhmarSchool of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, IranMohammad-RezaElhamiSchool of Mechanical Engineering, College of Engineering, University of Imam Hossein, Tehran, IranBehzadOsanlooSchool of Mechanical Engineering, College of Engineering, University of Tabriz, Tabriz, IranJournal Article20151201In present work, numerical analysis of three novel PEM fuel cells with tubular geometry was conducted. Tree different cross section was considered for PEM, namely: circular, square and triangular. Similar boundary and operational conditions is applied for all the geometries. At first, the obtained polarization curve for basic architecture fuel cells was validated with experimental data and then results of novel tubular three architectures were compared with basic conventional geometry. The results showed that for one case in V=0.4 volt, circular and square tubular models gives up to 27.5 and 8 percent outlet current density more than base model, whereas in triangular model predicts the decrease of 14.37 percent compared to the base model. Because square tubular and in particular circular tubular models doesn’t have sharp edges, uniform reaction could take place in allover the catalyst layer of cathode and anode electrodes and therefore the distribution of the hydrogen, oxygen and water is uniform. Also circular geometry due to use of all the reaction surface and lacking of dead zones produces higher power outputs. The temperature distribution in lateral direction in the reaction zone for three configurations indicates that maximum temperature for circular tubular has the lowest values in comparison to two other cases that is resulting from uniform surface reaction for this geometry. The results presented in this paper can be used for designing novel architecture of fuel cells.https://hfe.irost.ir/article_212_1534b76d325a8f591b52d302e7181331.pdfIranian Research Organization for Science and Technology (IROST)Hydrogen, Fuel Cell & Energy Storage2980-85372320150801Study the stability of Si, Ge, Fe and Co in the interior surface of metallic carbon nanotube for hydrogen storage19720521310.22104/ijhfc.2015.213ENHadiArabiRenewable energies, Magnetism and Nanotechnology Research Laboratory; Department of Physics, Ferdowsi University of MashhadS.VahidHosseiniRenewable Energies, Magnetism and Nanotechnology Research lab., Department of Physics, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, IranAhmadKompanyRenewable Energies, Magnetism and Nanotechnology Research Lab.,
Department of Physics, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, IranJournal Article20151112In this article, we have performed calculations for studying the stability of the carbon group elements such as Si and Ge and also the magnetic elements like Fe and Co via first principle investigations. We found that Si and Ge decoupled from the interior surface of carbon nanotubes, this fact was independent in curvature, radius, conductivity and numbers of atoms in the carbon nanotubes. But the magnetic elements bonded to the surface of the tube via electronegativity factor. The binding energy calculated for Co is -3.82 eV which is more stable than that of Fe (-2.65 eV) due to decrease more in its magnetization. The magnetization of Fe and Co changed from 4.00 μ_B to 3.40 μ_B and 3.00 μ_B to 1.75μ_B respectively. Finally, we came to conclusion that carbon group elements are favorable for hydrogen absorption inside the carbon nanotube whereas the magnetic elements are suitable for hydrogen adsorption.https://hfe.irost.ir/article_213_979d472a84804b9f647bc185a877a8b5.pdf