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Catalytic ortho- to parahydrogen conversion in liquid hydrogen

Karlsson, Emil LU (2017) In Degree project FKM820 20172
Materials Engineering
Abstract
The kinetics of the catalytic conversion of ortho- to parahydrogen was studied for the two catalysts, IONEX® and OXISORB®. The study also involved the optimization of an experimental technique for the conversion of orthohydrogen in a static setup. The main focus of the optimization being directed towards the analytical setup, where the acquisition of information and interpretation of the data were two main points for optimization. The rate of conversion is an important factor regarding the choice of catalyst for the future ESS hydrogen loop. A parahydrogen concentration of 99.5% has been determined as the lowest concentration yield from the catalytic conversion process. Both catalyst showed a good performance for the conversion of ortho-... (More)
The kinetics of the catalytic conversion of ortho- to parahydrogen was studied for the two catalysts, IONEX® and OXISORB®. The study also involved the optimization of an experimental technique for the conversion of orthohydrogen in a static setup. The main focus of the optimization being directed towards the analytical setup, where the acquisition of information and interpretation of the data were two main points for optimization. The rate of conversion is an important factor regarding the choice of catalyst for the future ESS hydrogen loop. A parahydrogen concentration of 99.5% has been determined as the lowest concentration yield from the catalytic conversion process. Both catalyst showed a good performance for the conversion of ortho- to parahydrogen, where a concentration of 99.7 to 99.8% parahydrogen was obtained from the experiments.
The kinetics for the catalyzed conversion of orthohydrogen using IONEX® and OXISORB® was determined to be based on first order exponential equations. The kinetics of IONEX® was described by a single first order exponential function. While the conversion of OXISORB® showed to be a function of two first order equations, which exhibits an independence as well as a codependence on one another.
The kinetics of conversion for the catalyst showed that the IONEX® catalyst is more efficient in converting ortho-hydrogen into parahydrogen. This is shown from the specific rate and the space velocity of the catalyst, based on the conditions of the experiment and the ESS hydrogen loop respectively.
Both catalysts appear to be suitable options for the future ESS hydrogen loop, where both catalysts possess the catalytic strength to compensate for the back conversion of parahydrogen during moderation of the emitted neutrons. The study shows that the IONEX® catalyst is the most efficient option but the final assessment would require a study of the long-term degenerative effects of the catalysts which could not be determined from the limited number of experiments carried out in this work. (Less)
Popular Abstract
High parahydrogen content is an important factor for the ESS liquid hydrogen moderator to maximize the neutron brightness. Parahydrogen is obtained by catalytic conversion of orthohydrogen and this thesis work is dedicated to the kinetic study of the orthohydrogen conversion for two types of catalysts. This will provide useful information for the selection of the catalyst to be used by ESS.
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author
Karlsson, Emil LU
supervisor
organization
course
FKM820 20172
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Orthohydrogen, Parahydrogen, Catalytic conversion, IONEX, OXISORB, Kinetics, ESS, Hydrogen, Liquid hydrogen, Moderator
publication/series
Degree project
report number
ISRN LUTFD2/TFMT--17/5056--SE
other publication id
ISRN
language
English
id
8929488
date added to LUP
2017-12-19 07:32:12
date last changed
2017-12-19 07:32:12
@misc{8929488,
  abstract     = {The kinetics of the catalytic conversion of ortho- to parahydrogen was studied for the two catalysts, IONEX® and OXISORB®. The study also involved the optimization of an experimental technique for the conversion of orthohydrogen in a static setup. The main focus of the optimization being directed towards the analytical setup, where the acquisition of information and interpretation of the data were two main points for optimization. The rate of conversion is an important factor regarding the choice of catalyst for the future ESS hydrogen loop. A parahydrogen concentration of 99.5% has been determined as the lowest concentration yield from the catalytic conversion process. Both catalyst showed a good performance for the conversion of ortho- to parahydrogen, where a concentration of 99.7 to 99.8% parahydrogen was obtained from the experiments. 
The kinetics for the catalyzed conversion of orthohydrogen using IONEX® and OXISORB® was determined to be based on first order exponential equations. The kinetics of IONEX® was described by a single first order exponential function. While the conversion of OXISORB® showed to be a function of two first order equations, which exhibits an independence as well as a codependence on one another. 
The kinetics of conversion for the catalyst showed that the IONEX® catalyst is more efficient in converting ortho-hydrogen into parahydrogen. This is shown from the specific rate and the space velocity of the catalyst, based on the conditions of the experiment and the ESS hydrogen loop respectively. 
Both catalysts appear to be suitable options for the future ESS hydrogen loop, where both catalysts possess the catalytic strength to compensate for the back conversion of parahydrogen during moderation of the emitted neutrons. The study shows that the IONEX® catalyst is the most efficient option but the final assessment would require a study of the long-term degenerative effects of the catalysts which could not be determined from the limited number of experiments carried out in this work.},
  author       = {Karlsson, Emil},
  keyword      = {Orthohydrogen,Parahydrogen,Catalytic conversion,IONEX,OXISORB,Kinetics,ESS,Hydrogen,Liquid hydrogen,Moderator},
  language     = {eng},
  note         = {Student Paper},
  series       = {Degree project},
  title        = {Catalytic ortho- to parahydrogen conversion in liquid hydrogen},
  year         = {2017},
}