Thesis (M.S.)--University of Missouri-Columbia, 2003. / Typescript. Includes bibliographical references (leaves 104-105). Also available on the Internet.

Thesis (M.S.)--University of Missouri-Columbia, 2003. / Typescript. Includes bibliographical references (leaves 104-105). Also available on the Internet.

Includes bibliographical references (p. 181-194).

Thesis (Ph.D)--Chemical Engineering, Georgia Institute of Technology, 2010. / Committee Chair: Fuller, Thomas; Committee Member: Beckham, Haskell; Committee Member: Hess, Dennis; Committee Member: Koros, William; Committee Member: Meredith, Carson. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains xii, 100 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 85-90).

Direct Methanol Fuel Cells (DMFC) provide an exciting alternative to current energy storage technologies for powering small portable electronic devices. For applications with sufficiently long durations of continuous operation, DMFC’s offer higher energy density, the ability to be refueled instead of recharged, and easier fuel handling and storage than devices that operate with hydrogen. At present, materials and manufacturing challenges impede performance and have prevented the entry of these devices to the marketplace. Higher-performing, cost-effective materials and efficient manufacturing processes are needed to enable the commercialization of DMFC. In a DMFC, the methanol-rich fuel stream and the oxidant are isolated from one another by a proton-conducting and electrically insulating membrane. Catalysts in the electrodes on either side of the Membrane Electrode Assembly (MEA) promote the two simultaneous half-reactions which allow the chemical energy carried in the fuel and oxidant to be converted directly into electricity. The goal of this research effort is to develop a continuous manufacturing process for the fabrication of effective DMFC MEAs. Based on the geometry of the electrode and materials used in the MEA, we propose a roll-to-roll process in which electrodes are coated onto a suitable substrate and subsequently assembled to form a MEA. Appropriate coating methods for electrode fabrication were identified by evaluating the requirements of continuous manufacturing processes; an appropriate set of these processes was then reduced to practice on a custom-designed flexible test bed designed explicitly for this project. After establishing baseline capabilities for several candidate methods, a spraying process was selected and a continuous manufacturing process concept was proposed. Finally, key control parameters of the spraying process were identified and their influence tested on actual MEAs to define optimal operating conditions. / text

No description available.

A steady-state simulation of a diesel-fuelled SOFC system was developed using a process simulation software package (VMGSim). The system was studied by conducting a sensitivity analysis of six independent variables (steam to carbon ratio, oxygen to carbon ratio, fuel utilization, air utilization, reformer pre-heater approach temperature and cathode temperature to the SOFC) and their effect on three response variables (net system efficiency, stack efficiency, system exhaust temperature). The steam to carbon ratio, fuel utilization and air utilization were the most influential independent variables and thus affected the greatest change in the performance metrics. Secondly, a multi-variable study was carried out on the most influential variables and constrained optima for the efficiencies (45% net system, 47% stack) and system exhaust temperature (78 degrees Celsius) were obtained. For the second part of this work, a steam reforming heat-exchange reactor was modeled using COMSOL. The reactor performance was assessed on the basis of selectivity and residence time for a given conversion. Both the kinetic models of Parmar et al. (2010) and Shi et al. (2009) for catalytic diesel steam reforming were applied and compared. Differences in performance were attributed to differences in the catalyst support and the reaction mechanisms used for deriving the reforming rate expressions. Finally, a proof of concept multi-scale modeling and design tool was developed by integrating the CFD model with the process simulation. Two-way communication between four different software components; COMSOL, VMGSim, Matlab and Microsoft Excel was achieved. / Thesis (Master, Chemical Engineering) -- Queen's University, 2012-04-18 01:12:27.072

No description available.

No description available.