The hydrogen molecule exists in two different isomers: ortho-hydrogen and para-hydrogen, that differ due to proton spin direction: it is parallel in the first case, and anti-parallel in the second case. The concentration of ortho or para hydrogen depends only on temperature: at room temperature, 75% of the H2 is in its ortho isomer and 25% in the para isomer. At cryogenic conditions however, almost 100% of liquid H2 is in its para-isomer state at equilibrium. This exothermic conversion can, for example cause significant boil-off of liquid hydrogen if not completed during the liquefaction process resulting in liquid hydrogen converting back into its gaseous form. This will clearly impact the overall efficiency of the H2 liquefaction process. An innovative catalyst for the required O-P H2 conversion has been proposed by Baker Hughes, which they report improves the overall energy efficiency of the H2 liquefaction process by up to 45%. Such catalysts are placed inside the required cryogenic heat exchangers to enable the O-P H2 conversion. The performance of the innovative catalyst for O-P conversion for hydrogen liquefaction needs to be tested at a lab-scale before commercialisation can be considered. This will be benchmarked against the current (only) commercial O-P H2 catalyst, IONEX.
Partners: Baker Hughes, The University of Western Australia
Project Leader: Prof. Michael Johns
Duration: 6 Months