الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
The latest fluctuations in the price of conventional energy have made the use of alternative fuels for the production of energy a necessity. At the same time. the increased world community consciousness on the environmental pollution. poses an imperative need for a shift to other environmentally friendly methods of energy production. One of the most promising alternative fuels. with significant technological development. is the hydrogen. The production of hydrogen can be realized either from conventional fuels or from friendlier to the environment methods. Hydrogen can be used in the marine field in three applications hydrogen internal combustion engines. hydrogen gas turbines. and hydrogen fuel cells. This thesis is concerned with the use of fuel cell power plant operated with different fuel types integrating clean hydrogen fuel. whether produced from renewable source or fossil fuel. to mitigate air pollution from ships.
Fuel cell systems are considered for powering future ships in an efficient and low emitting manner. They are environmentally friendly source of energy due to their super-efficient use of fuel for electricity and heat. Among the currently available fuel cell technologies. Molten Carbonate Fuel Cell (MCFC) and Proton Exchange Membrane Fuel Cell (PEMFC) are considered the most promising options for marine applications. For the near future. fuel cells can replace the diesel generator. and the PEMFC has an advantage over the MCFC of having shorter start up time.
Therefore. in this thesis a simple model for PEMFC has been developed. The model includes chemical and thermodynamic relations governing the fuel cell operation and also the effect of operating conditions on cell performance. Understanding the impact of various parameters such as temperature. pressure. and gas constituents on performance allows fuel cell developers to optimize their design of the modular units and allows process engineers to maximize the performance of system applications. PEMFC has shown better performance characteristics at different loading conditions than diesel generator and micro gas turbine.
PEM fuel cells generate electrical power from air and from hydrogen or hydrogen rich gas mixtures. Hence. there is a great interest in converting current hydrocarbon based marine fuels such as natural gas. gasoline. and diesel into hydrogen rich gases acceptable to the PEM fuel cells on board ships. Using chemical flow sheeting software. the total system efficiency has been calculated. Natural gas appears to be the best fuel for hydrogen rich gas production due to its favorable composition of lower molecular weight compounds. The present study has shown that steam-reforming process is the most competitive fuel processing option in terms of fuel processing efficiency. Partial oxidation process has proved to posses the lowest fuel processing efficiency. Among the options studied. the highest fuel processing efficiency is achieved with natural gas steam reforming system.