Dissertation
A HIGH-FIDELITY, CONTINUOUS ORTHO-PARAHYDROGEN MEASUREMENT AND CONVERSION SYSTEM
Washington State University
Doctor of Philosophy (PhD), Washington State University
01/2021
DOI:
https://doi.org/10.7273/000001865
Handle:
https://hdl.handle.net/2376/123274
Abstract
Production and consumption of liquid hydrogen is set to increase many orders of magnitude in the upcoming decades. Yet an entire liquid shipment can be boiled-off from the exothermic ortho-parahydrogen reaction if not performed during liquefaction. Measurements of ortho-parahydrogen composition have been historically challenging which hinders routine analysis. Included are experimental results of a continuous flow, in-situ Raman spectroscopy system for sampling ortho-parahydrogen composition. Correlation between Raman peak intensities and ortho-parahydrogen ratios demonstrates the actual number of molecules present in a given J mode is dependent on Boltzmann distribution, partition function, anisotropic polarizability, and scattering frequency. Consistent definitions of orthohydrogen percentage as related to Raman peak areas allow true orthohydrogen percentages to be obtained from sub 80K sample temperatures. The degeneracy of J mode populations as described by full statistical thermodynamics allows a correction to obtain true orthohydrogen percentages. This correction is completed with known experimental peak areas which correspond to confirmed equilibrium orthohydrogen percentage values. Simultaneous Raman measurement before and after catalytic packed bed and vortex tube ortho-parahydrogen conversion devices allow improved measurement to verify conversion performance. For example, a catalyzed dual outlet vortex tube produced a raw Raman measured para-orthohydrogen conversion of 6.3% from inlet to outlet. When calibrated to the true orthohydrogen percentage, it equates to 7.3% compared to the theoretical of 8.7% based off experimental temperature differentials. The results indicate application in optimizing liquefaction packed bed and reducing boil-off through vortex tube related heat exchangers applications. Together, these methods of orthohydrogen and parahydrogen conversion and measurement allow for increased liquid hydrogen storage optimization.
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Details
- Title
- A HIGH-FIDELITY, CONTINUOUS ORTHO-PARAHYDROGEN MEASUREMENT AND CONVERSION SYSTEM
- Creators
- Carl Dale Bunge
- Contributors
- Jacob Leachman (Advisor)Konstantin Matveev (Advisor)Dustin McLarty (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Mechanical and Materials Engineering, School of
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Publisher
- Washington State University
- Number of pages
- 300
- Identifiers
- 99900606554201842
- Language
- English
- Resource Type
- Dissertation