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dc.contributor.advisorErnest G. Cravalho.en_US
dc.contributor.authorRuflin, Justin, 1981-en_US
dc.contributor.otherMassachusetts Institute of Technology. Dept. of Mechanical Engineering.en_US
dc.date.accessioned2007-01-10T16:54:10Z
dc.date.available2007-01-10T16:54:10Z
dc.date.copyright2006en_US
dc.date.issued2006en_US
dc.identifier.urihttp://hdl.handle.net/1721.1/35638
dc.descriptionThesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006.en_US
dc.descriptionIncludes bibliographical references (leaves 74-75).en_US
dc.description.abstractAt present, most fuel cells employ porous gas diffusion (PGD) electrodes. Although much effort has been spent on their development, the performance and cost of PGD electrodes are still major obstacles to the successful commercialization of fuel cells. As a means to bypass the drawbacks associated with PGD electrodes, several researchers have taken an alternative approach to electrode design by considering fluidized bed electrodes (FBEs), a type of flooded electrode that relies on convective rather than diffusive mass transport. Several reviews and past studies claim that FBEs have the potential for reaching high power density at a low cost due to several inherent advantages. However, the results so far of fluidized bed electrodes applied to fuel cells have been poor, and the past studies have not offered effective explanations for the discrepancy between expected and actual performance. A fluidized bed electrode model has been developed and applied to the data obtained by previous researchers in order to explain the poor performance of these past designs. As points of comparison, models have also been developed to predict the performance of packed bed electrodes and screen electrodes (two other flooded electrode designs).en_US
dc.description.abstract(cont.) Separate models have been developed to consider both ionic and mass transport. Upper bounds on the performance of all three electrodes have been established, and then compared to the performance of PGD electrodes. The results of the models indicate that the PGD electrodes perform better than the packed bed or screen electrodes by at least a factor of two, unless the flooded electrodes are very short (on the order of millimeters). Both mass transfer and the saturation concentration of oxygen in the electrolyte serve as limitations in the flooded designs. The models also indicate that the two-phase and three-phase FBEs are inferior to the other flooded electrodes. The paper concludes with several recommendations for further work, including methods to boost performance.en_US
dc.description.statementofresponsibilityby Justin Ruflin.en_US
dc.format.extent75 leavesen_US
dc.format.extent4931223 bytes
dc.format.extent4934293 bytes
dc.format.mimetypeapplication/pdf
dc.format.mimetypeapplication/pdf
dc.language.isoengen_US
dc.publisherMassachusetts Institute of Technologyen_US
dc.rightsM.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.en_US
dc.rights.urihttp://dspace.mit.edu/handle/1721.1/7582
dc.subjectMechanical Engineering.en_US
dc.titleThe performance of fluidized beds, packed beds, and screens as fuel cell electrodesen_US
dc.typeThesisen_US
dc.description.degreeS.M.en_US
dc.contributor.departmentMassachusetts Institute of Technology. Department of Mechanical Engineering
dc.identifier.oclc76701807en_US


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