IEC 14 |
| M.A. Matthews, James Sharp, Rita Aiello, and Thomas Davis. Department of Chemical Engineering, University of South Carolina, 300 Main St., Columbia, SC 29208 |
| Fuel cells are a promising source of green electric power, but the problem of hydrogen storage and generation is a limiting factor. The objective of this work was to develop a method of producing clean H2, with no CO or CO2 emissions, for use in small fuel cells. This would eliminate the problems associated with high pressure hydrogen storage tanks. Water, either as liquid or vapor, will react with solid inorganic hydrides such as NaBH4 to produce pure hydrogen. However, a number of limitations are inherent in the liquid-solid reaction. The insoluble hydrolysis products are extremely basic and high pH inhibits the reaction. A large excess of acid, or a catalyst, must be added to the mixture in order to force the reaction to completion. Furthermore, the liquid-solid reaction is inefficient on a weight basis because a large excess of the water-acid mixture must be used to obtain acceptable yields of hydrogen. The vapor-solid reaction overcomes some of these limitations. An isothermal semi-batch reactor was constructed to test the concept of steam hydrolysis of chemical hydrides. For some hydrides, nearly 100 percent yield of hydrogen was obtained by contacting the hydride with pure steam at temperatures near 100°C. Hydrogen yield depended strongly on temperature and, to a lesser extent, on flow rate of steam. A thermodynamic analysis suggests that it may be practical to develop an autothermal hydrogen generation system. |
|
Green Chemistry in the Design of Alternative Energy Strategies (sponsored by Green Chemistry & Engineering Subdivision)
8:30 AM-12:05 PM, Sunday, March 23, 2003 Convention Center -- Room 394, Oral
Division of Industrial and Engineering Chemistry |