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You searched for +publisher:"Colorado School of Mines" +contributor:("Paglieri, Stephen N."). Showing records 1 – 2 of 2 total matches.

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Colorado School of Mines

1. Abu El Hawa, Hani W. Synthesis and characterization of thermally stable palladium-based composite membranes for high temperature applications.

Degree: PhD, Chemical and Biological Engineering, 2015, Colorado School of Mines

In this thesis, the inert gas leak evolution problem in electroless-plated palladium-based composite membranes has been revisited. Palladium was doped with a higher melting point element such as ruthenium or platinum and the rate of increase of the nitrogen leak in the temperature range of 500-600 ºC was determined. The results showed that doping Pd with Pt or Ru significantly reduces the leak growth rate compared to a pure Pd membrane by almost one order of magnitude. The addition of Ru to Pd was sufficient to lower the leak growth rate, though the hydrogen permeance stability was not improved. The Pd-Pt alloy membrane, despite having a lower hydrogen permeance, had a stable hydrogen flux at higher temperatures. The influence of high temperature annealing (> 640 ºC) on the thermal stability of pure Pd composite membranes was also investigated in order to correlate between thermal stability and microstructural evolution. Pure Pd composite membranes were subjected to different high temperature annealing processes. It was found that employing such heat treatments improved the thermal stability of the membranes when operated at lower temperatures; evidenced by a suppression of the rate at which hydrogen selectivity towards nitrogen declined over time. SEM images of the microstructural evolution as a function of temperature revealed that porosity, which is typically present in as-deposited electroless plated films, is significantly reduced after heat treatment. Thermal stability was also evaluated in actual steam methane reforming (SMR) environments. Thin film (~5.0 µm thick) Pd-Ru and Pd-Au composite membranes were fabricated and used to carry out SMR over commercial Ni or Ru based catalysts at temperatures > 480 °C and pressures up to 2.9 MPa. The conversions obtained (≥ 80%) were significantly higher than the thermodynamic equilibrium predicted (< 35%) for the feed composition at these process conditions. The long term operation (> 500 hours) revealed the potential suitability of these Pd-alloys to be candidates for use in SMR membrane reactors at temperature as high as 600 °C. The permeate hydrogen flux and methane conversion were stable and the hydrogen permeate purity ranged from 93 to 99.7% depending on the operating conditions. Advisors/Committee Members: Way, J. Douglas (advisor), Tong, Jianhua (committee member), Carreon, Moises A. (committee member), Paglieri, Stephen N. (committee member).

Subjects/Keywords: Electroless plating; Hydrogen separation; Steam methane reforming; Hydrogen production; Catalytic membrane reactor; Palladium-based composite membranes

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Abu El Hawa, H. W. (2015). Synthesis and characterization of thermally stable palladium-based composite membranes for high temperature applications. (Doctoral Dissertation). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/20155

Chicago Manual of Style (16th Edition):

Abu El Hawa, Hani W. “Synthesis and characterization of thermally stable palladium-based composite membranes for high temperature applications.” 2015. Doctoral Dissertation, Colorado School of Mines. Accessed April 10, 2020. http://hdl.handle.net/11124/20155.

MLA Handbook (7th Edition):

Abu El Hawa, Hani W. “Synthesis and characterization of thermally stable palladium-based composite membranes for high temperature applications.” 2015. Web. 10 Apr 2020.

Vancouver:

Abu El Hawa HW. Synthesis and characterization of thermally stable palladium-based composite membranes for high temperature applications. [Internet] [Doctoral dissertation]. Colorado School of Mines; 2015. [cited 2020 Apr 10]. Available from: http://hdl.handle.net/11124/20155.

Council of Science Editors:

Abu El Hawa HW. Synthesis and characterization of thermally stable palladium-based composite membranes for high temperature applications. [Doctoral Dissertation]. Colorado School of Mines; 2015. Available from: http://hdl.handle.net/11124/20155


Colorado School of Mines

2. Howard, Cameron Tyler. Behavior of palladium as a getter for lanthanide fission products in U-Mo-Ti-Zr fast reactor fuels, The.

Degree: PhD, Metallurgical and Materials Engineering, 2017, Colorado School of Mines

One of the hurdles to extending the life of metallic fast reactor fuel alloys is Fuel-Clad Chemical Interaction (FCCI), a phenomenon which occurs between fuel and cladding resulting in thinning of the cladding. The cause of FCCI is the reaction between cladding constituents (e.g. iron and nickel) and lanthanide fission products generated in the fuel (e.g. lanthanum and cerium). This interaction can produce localized melting of the cladding, reducing its thickness over the life of the fuel element. It has been suggested that FCCI can be hindered by doping the fuel with palladium, a candidate getter for lanthanide fission products. There is therefore interest in demonstrating the efficacy of this particular lanthanide getter for realistic fast reactor fuel analogues. Work is presented based on the U-M (M=50Mo-43Ti-7Zr, wt. pct.) alloy system both with, and without, palladium additions. The research was conducted using depleted uranium alloys developed as metallurgical surrogates for real spent fuels. Burnup was simulated using cerium as a mock lanthanide fission product to assess the behavior of palladium with respect to fuel and cladding constituents. The behavior of palladium in terms of microstructural evolution was studied from both as-cast and annealed surrogate fuel specimens as well as diffusion couples between surrogate fuel alloys and type HT-9 stainless steel cladding. Results derived from characterization of these metallurgical surrogate experiments are presented and it is shown that palladium is a promising getter for lanthanide fission products in the given alloy system. Advisors/Committee Members: Mishra, Brajendra (advisor), Olson, D. L. (David LeRoy) (advisor), Porter, Jason M. (committee member), Liu, Stephen (committee member), King, Jeffrey C. (committee member), Paglieri, Stephen N. (committee member).

Subjects/Keywords: Lanthanide; Reactor; Fission; Uranium; Palladium

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Howard, C. T. (2017). Behavior of palladium as a getter for lanthanide fission products in U-Mo-Ti-Zr fast reactor fuels, The. (Doctoral Dissertation). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/171847

Chicago Manual of Style (16th Edition):

Howard, Cameron Tyler. “Behavior of palladium as a getter for lanthanide fission products in U-Mo-Ti-Zr fast reactor fuels, The.” 2017. Doctoral Dissertation, Colorado School of Mines. Accessed April 10, 2020. http://hdl.handle.net/11124/171847.

MLA Handbook (7th Edition):

Howard, Cameron Tyler. “Behavior of palladium as a getter for lanthanide fission products in U-Mo-Ti-Zr fast reactor fuels, The.” 2017. Web. 10 Apr 2020.

Vancouver:

Howard CT. Behavior of palladium as a getter for lanthanide fission products in U-Mo-Ti-Zr fast reactor fuels, The. [Internet] [Doctoral dissertation]. Colorado School of Mines; 2017. [cited 2020 Apr 10]. Available from: http://hdl.handle.net/11124/171847.

Council of Science Editors:

Howard CT. Behavior of palladium as a getter for lanthanide fission products in U-Mo-Ti-Zr fast reactor fuels, The. [Doctoral Dissertation]. Colorado School of Mines; 2017. Available from: http://hdl.handle.net/11124/171847

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