Quantitative in-situ monitoring of parahydrogen fraction using Raman spectroscopy

Andrew J. Parrott, Paul Dallin, John Andrews, Peter M. Richardson, Olga Semenova, Meghan E. Halse, Simon B. Duckett, Alison Nordon

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Raman spectroscopy has been used to provide a rapid, non-invasive and non-destructive quantification method for determining the parahydrogen fraction of hydrogen gas. The basis of the method is the measurement of the ratio of the first two rotational bands of hydrogen at 355cm−1 and 586cm−1 corresponding to parahydrogen and orthohydrogen, respectively. The method has been used to determine the parahydrogen content during a production process and a reaction. In the first example, the performance of an in-house liquid nitrogen cooled parahydrogen generator was monitored both at-line and on-line. The Raman measurements showed that it took several hours for the generator to reach steady state and hence, for maximum parahydrogen production (50 %) to be reached. The results obtained using Raman spectroscopy were compared to those obtained by at-line low-field NMR spectroscopy. While the results were in good agreement, Raman analysis has several advantages over NMR for this application. The Raman method does not require a reference sample, as both spin isomers (ortho and para) of hydrogen can be directly detected, which simplifies the procedure and eliminates some sources of error. In the second example, the method was used to monitor the fast conversion of parahydrogen to orthohydrogen in-situ. Here the ability to acquire Raman spectra every 30s enabled a conversion process with a rate constant of 27.4 × 10−4 s−1 to be monitored. The Raman method described here represents an improvement on previously reported work, in that it can be easily applied on-line and is approximately 500 times faster. This offers the potential of an industrially compatible method for determining parahydrogen content in applications that require the storage and usage of hydrogen.
LanguageEnglish
Number of pages10
JournalApplied Spectroscopy
Early online date11 Sep 2018
DOIs
Publication statusE-pub ahead of print - 11 Sep 2018

Fingerprint

Raman spectroscopy
Hydrogen
Monitoring
hydrogen
generators
nuclear magnetic resonance
Liquid nitrogen
liquid nitrogen
Isomers
Nuclear magnetic resonance spectroscopy
Raman scattering
Rate constants
isomers
Gases
Nuclear magnetic resonance
Raman spectra
gases
spectroscopy

Keywords

  • Raman spectroscopy
  • quantitative analysis
  • in-situ monitoring
  • gas analysis
  • hydrogen
  • parahydrogen

Cite this

Parrott, Andrew J. ; Dallin, Paul ; Andrews, John ; Richardson, Peter M. ; Semenova, Olga ; Halse, Meghan E. ; Duckett, Simon B. ; Nordon, Alison. / Quantitative in-situ monitoring of parahydrogen fraction using Raman spectroscopy. In: Applied Spectroscopy. 2018.
@article{0a295dbc1aa6451cae41c48d304c2046,
title = "Quantitative in-situ monitoring of parahydrogen fraction using Raman spectroscopy",
abstract = "Raman spectroscopy has been used to provide a rapid, non-invasive and non-destructive quantification method for determining the parahydrogen fraction of hydrogen gas. The basis of the method is the measurement of the ratio of the first two rotational bands of hydrogen at 355cm−1 and 586cm−1 corresponding to parahydrogen and orthohydrogen, respectively. The method has been used to determine the parahydrogen content during a production process and a reaction. In the first example, the performance of an in-house liquid nitrogen cooled parahydrogen generator was monitored both at-line and on-line. The Raman measurements showed that it took several hours for the generator to reach steady state and hence, for maximum parahydrogen production (50 {\%}) to be reached. The results obtained using Raman spectroscopy were compared to those obtained by at-line low-field NMR spectroscopy. While the results were in good agreement, Raman analysis has several advantages over NMR for this application. The Raman method does not require a reference sample, as both spin isomers (ortho and para) of hydrogen can be directly detected, which simplifies the procedure and eliminates some sources of error. In the second example, the method was used to monitor the fast conversion of parahydrogen to orthohydrogen in-situ. Here the ability to acquire Raman spectra every 30s enabled a conversion process with a rate constant of 27.4 × 10−4 s−1 to be monitored. The Raman method described here represents an improvement on previously reported work, in that it can be easily applied on-line and is approximately 500 times faster. This offers the potential of an industrially compatible method for determining parahydrogen content in applications that require the storage and usage of hydrogen.",
keywords = "Raman spectroscopy, quantitative analysis, in-situ monitoring, gas analysis, hydrogen, parahydrogen",
author = "Parrott, {Andrew J.} and Paul Dallin and John Andrews and Richardson, {Peter M.} and Olga Semenova and Halse, {Meghan E.} and Duckett, {Simon B.} and Alison Nordon",
year = "2018",
month = "9",
day = "11",
doi = "10.1177/0003702818798644",
language = "English",
journal = "Applied Spectroscopy",
issn = "0003-7028",

}

Quantitative in-situ monitoring of parahydrogen fraction using Raman spectroscopy. / Parrott, Andrew J.; Dallin, Paul; Andrews, John; Richardson, Peter M.; Semenova, Olga; Halse, Meghan E.; Duckett, Simon B.; Nordon, Alison.

In: Applied Spectroscopy, 11.09.2018.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Quantitative in-situ monitoring of parahydrogen fraction using Raman spectroscopy

AU - Parrott, Andrew J.

AU - Dallin, Paul

AU - Andrews, John

AU - Richardson, Peter M.

AU - Semenova, Olga

AU - Halse, Meghan E.

AU - Duckett, Simon B.

AU - Nordon, Alison

PY - 2018/9/11

Y1 - 2018/9/11

N2 - Raman spectroscopy has been used to provide a rapid, non-invasive and non-destructive quantification method for determining the parahydrogen fraction of hydrogen gas. The basis of the method is the measurement of the ratio of the first two rotational bands of hydrogen at 355cm−1 and 586cm−1 corresponding to parahydrogen and orthohydrogen, respectively. The method has been used to determine the parahydrogen content during a production process and a reaction. In the first example, the performance of an in-house liquid nitrogen cooled parahydrogen generator was monitored both at-line and on-line. The Raman measurements showed that it took several hours for the generator to reach steady state and hence, for maximum parahydrogen production (50 %) to be reached. The results obtained using Raman spectroscopy were compared to those obtained by at-line low-field NMR spectroscopy. While the results were in good agreement, Raman analysis has several advantages over NMR for this application. The Raman method does not require a reference sample, as both spin isomers (ortho and para) of hydrogen can be directly detected, which simplifies the procedure and eliminates some sources of error. In the second example, the method was used to monitor the fast conversion of parahydrogen to orthohydrogen in-situ. Here the ability to acquire Raman spectra every 30s enabled a conversion process with a rate constant of 27.4 × 10−4 s−1 to be monitored. The Raman method described here represents an improvement on previously reported work, in that it can be easily applied on-line and is approximately 500 times faster. This offers the potential of an industrially compatible method for determining parahydrogen content in applications that require the storage and usage of hydrogen.

AB - Raman spectroscopy has been used to provide a rapid, non-invasive and non-destructive quantification method for determining the parahydrogen fraction of hydrogen gas. The basis of the method is the measurement of the ratio of the first two rotational bands of hydrogen at 355cm−1 and 586cm−1 corresponding to parahydrogen and orthohydrogen, respectively. The method has been used to determine the parahydrogen content during a production process and a reaction. In the first example, the performance of an in-house liquid nitrogen cooled parahydrogen generator was monitored both at-line and on-line. The Raman measurements showed that it took several hours for the generator to reach steady state and hence, for maximum parahydrogen production (50 %) to be reached. The results obtained using Raman spectroscopy were compared to those obtained by at-line low-field NMR spectroscopy. While the results were in good agreement, Raman analysis has several advantages over NMR for this application. The Raman method does not require a reference sample, as both spin isomers (ortho and para) of hydrogen can be directly detected, which simplifies the procedure and eliminates some sources of error. In the second example, the method was used to monitor the fast conversion of parahydrogen to orthohydrogen in-situ. Here the ability to acquire Raman spectra every 30s enabled a conversion process with a rate constant of 27.4 × 10−4 s−1 to be monitored. The Raman method described here represents an improvement on previously reported work, in that it can be easily applied on-line and is approximately 500 times faster. This offers the potential of an industrially compatible method for determining parahydrogen content in applications that require the storage and usage of hydrogen.

KW - Raman spectroscopy

KW - quantitative analysis

KW - in-situ monitoring

KW - gas analysis

KW - hydrogen

KW - parahydrogen

UR - http://journals.sagepub.com/home/asp

U2 - 10.1177/0003702818798644

DO - 10.1177/0003702818798644

M3 - Article

JO - Applied Spectroscopy

T2 - Applied Spectroscopy

JF - Applied Spectroscopy

SN - 0003-7028

ER -