Type 3 porous liquids for hydrogen and oxygen separation and assessment of an alternative regeneration technique

Selectivity for oxygen over helium was high in all type 3 porous liquids but decreased with increasing pressure, porous liquid solid loading, and helium concentration in the feed.<br><br>Hydrogen and oxygen separation using H-ZSM-5 in PDMS was modelled in Aspen Plus®. A regression model was developed to obtain unique Henry’s constant parameters for hydrogen and oxygen in H-ZSM-5 in PDMS, facilitating simulation of separation in an absorption column.

The energy consumption of the separation process, including regeneration, was determined. Full separation was not achieved with H-ZSM-5 in PDMS, so the absorption model was combined with flash cryogenic separation to yield highly pure hydrogen and oxygen streams. The combined model showed reduced energy consumption compared to using flash cryogenic separation alone.<br><br>Sparging regeneration of type 3 porous liquids was also assessed.

Hydrogen was used to regenerate a carbon dioxide saturated porous liquid, with elevated temperatures enhancing desorption. Optimised sparging parameters produced a hydrogen-carbon dioxide mixture that could be used for sustainable chemical production, such as methane or methanol. Sparging not only regenerated porous liquids efficiently but also offers potential for coupling with chemical production processes.<br><br><i>Thesis is embargoed until 31 December 2026.</i>