Sodium borohydride (NaBH4) offers a simple and safe technology for storage and on demand production of hydrogen being a promising and a feasible method for fuel cell applications.
The objectives of the present study are to emphasize the role of sodium borohydride as a part of future hydrogen energy system, to investigate the kinetics of the catalytic hydrolysis reaction of NaBH4 in a batch and flow system with respect to temperature, concentration, catalyst and flow rate for flow reactor by proposing a kinetic model and finally based on kinetic analysis, to design a prototype reactor to meet the hydrogen requirement for a 100W PEM fuel cell and operate it in steady state conditions.
To express hydrolysis reaction by a kinetic model, series of batch experiments was performed in a glass flask (30mL) where the following parameters were systematically changed: the solution temperature varied as 20, 30 and 50° / C, the NaBH4 concentration changed as 0.17, 0.23 and 0.3M, NaOH concentration varied as 0.27, 1.32 and 2.85M and catalyst amount was changed as 0.048, 0.07 and 0.1g Pt/C (ETEK® / ). In the kinetic model catalyst effect proposed within the rate constant. The kinetic model was purposed as:
For flow reactor system, in a differential glass reactor (5mL) concentration, catalyst amount, catalyst type and flow rate was systematically analyzed at a constant temperature. For Pt/C catalyst the purposed model was:
Also, for intrazeolite Co(0) nanoclusters, as a result of controlled experiments, the rate expression was found as:
Based on these data prototype reactor (recycle) with internal volume of 122cm3 and storage volume of 1336 cm3 was designed, manufactured from Delrin® / and operated.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12613639/index.pdf |
| Date | 01 September 2011 |
| Creators | Boran, Asli |
| Contributors | Eroglu, Inci |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
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