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  • Article
    Citation - WoS: 8
    Citation - Scopus: 9
    Can Fool's Gold "pyrite" Become Real Gold as a Catalyst for Clean-Energy H2 Production?
    (Pergamon-elsevier Science Ltd, 2019) Inger, Erk; Inger, Erk
    The natural, most abundant sulfide mineral of pyrite was modified using polyethyleneimine (PEI) for use as a catalyst in H-2 release reactions from NaBH4 in methanol. The catalytic performances of pyrite, pyrite-PEI, and protonated pyrite-PEI (pyrite-PEI+) were compared and the hydrogen generation rate (HGR) values of 795 +/- 26, 2883 +/- 190, and 4320 +/- 188 mL H-2/(g of catalyst x min)(-1) were measured for H-2 production from NaBH4 methanolysis. The effect of methanol:water mixture at various ratios, the amount of catalyst, the concentration of NaBH4, and temperature on H-2 production from NaBH4 in methanol catalyzed by pyrite-PEr were investigated. The activation energies for pyrite-PEI, and pyrite-PEI+ catalyzed H-2 release reactions were calculated as 47.2 and 36.8 kJ/mol, respectively. It was found that the activity % for the pyrite-PEI+ catalyst decreased to 76.2 +/- 2.7% after five consecutive uses with 100% conversion for each re-use study. Furthermore, the re-generation of pyrite-PEI+ catalyst after the 5th usage was readily ensured by HCl treatment to completely recover and further increase the activity% of the catalyst. Therefore, pyrite was shown to be a useful re-generable and economic green catalyst for H-2 production in many potential applications. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
  • Article
    Citation - WoS: 10
    Citation - Scopus: 13
    Electromagnetic Launching Systems To Geosynchronously Equatorial Orbit in Space and Cost Calculations
    (Ieee-inst Electrical Electronics Engineers inc, 2017) Inger, Erk; Inger, Erk
    Electromagnetic launching mass driver system (projectile) has been examined and evaluated as an eligible alternative to the chemical propulsion systems, in space transportation. The projectile has been arranged to reach to its orbital speed at delivered altitude, with an energy transferred externally to a projectile all the flyway through the electromagnetic launcher. The multistage electromagnetic launcher structure contains the capacitors for storing energy and transfers this energy through a switching inductor to a mass driver. The mass driver is synchronously being energized by a voltage through an oscillating coil-capacitor circuit. This paper presents dependence and optimization of design and performance parameters of coilgun equations. Cost estimations of electromagnetic launching system are also calculated in energy per unit mass.