Ortho- para hydrogen conversion applied to hydrogen liquefaction

R&D Focus Areas:
Liquid hydrogen

Lead Organisation:
CSIRO, University of Western Australia (UWA)

Partners:
Not applicable

Status:
Completed

Start date:
October 2020

Completion date:
September 2023

Key contacts:
Dr Liangguang Tang: Liangguang.tang@csiro.au
Professor Michael Johns: michael.johns@uwa.edu.au

Funding:
CSIRO Hydrogen Future Science Program (FSP) and UWA, CSIRO ERP program

Project total cost:
CSIRO FSP and UWA: total of AUD$143,125 (plus in-kind)
CSIRO ERP Program: total of AUD$220,714

Project summary description:
The emerging hydrogen economy requires the safe and efficient transportation of liquid hydrogen. Hydrogen (H2) is however a mixture of ortho-and para-H2 whose concentration is 75:25 at normal conditions. For the liquefaction of hydrogen, the thermodynamic equilibrium shifts towards para-H2 at low temperatures, but the conversion is hindered by slow kinetics. This poses a risk for the transport of liquid hydrogen as the conversion reaction is exothermic and can lead to excessive boil-off during liquid hydrogen storage.

In this project, small scale ortho-para hydrogen conversion (OPC) testing equipment has been designed and manufactured and was used for catalyst activation and activity testing under LN2 temperature. Ortho-para- hydrogen determination based on Raman and thermal conductivity methods has been setup and successfully applied to the determination of the ortho/para concentration inline.

The kinetics of the OPC is being quantitatively measured in the presence of commercially available Iron based catalyst and the results agreed well with the literature data. Various pretreatment condition used for catalyst activation has been tested and it was found the OPC activity strongly depended on the activation conditions. New types of iron-based catalysts have also been tested and the magnetic properties of the catalyst are believed to responsible for the catalyst activity.

The integration of catalyst into the plate fin heat exchanger has been modelled. It was identified that the outlet parahydrogen fraction is determined to be considerably (~10 times) more sensitive to reaction rate kinetics relative to heat transfer: therefore, the reactor geometry will be primarily determined by conversion kinetics.

Related publications and key links:

• Hydrogen ortho-para conversion: process sensitivities and optimisation, Chemical Engineering & Processing: Process Intensification 184 (2023) 109272, 10.1016/j.cep.2023.109272
• Evaluation and Outlook for Australian Renewable Energy Export via Circular Liquid Hydrogen Carriers, accepted for publication in the International Journal of Hydrogen Energy.

Higher degree studies supported:
This project supported one PhD student from UWA (whose studies will be completed in 2024).

 

October 2023