Solid formation kinetics in energy production and cryogenic liquefaction processes

R&D Focus Area:
Liquid hydrogen

Lead Organisation:
The University of Western Australia

Funding:
Future Energy Exports CRC (PhD Project)

Status:
Active

Start date:
2022

Completion date:
2025

Project summary description:
This project aims to reduce unplanned shutdowns due to the freeze-out of solid impurities during LNG and LH₂ liquefaction. At the low temperatures present during these liquefaction processes, it is thermodynamically favourable for many impurities in these fluids to form a solid phase at the process pressure. To reduce the risk of a solid blockage, the concentration of these impurities in the process stream is lowered by unit operations (typically to the order of parts-per-million) prior to liquefaction.

Despite these low concentrations, the solid phase of many impurities remains thermodynamically stable, meaning they can still “freeze-out” and accumulate over time. This represents an economic and safety risk to liquefaction plants as these solids can block process equipment, necessitating shutdowns. Significant knowledge gaps in both the solubility (i.e. the melting temperature) and the formation onset conditions (i.e. the freezing temperature and time-to-form) of these solids prevent liquefaction plant operators from making informed engineering decisions during plant design and operation.

To address these knowledge gaps, this project will measure both solid-fluid equilibrium and solid formation onset kinetics for two systems:

1. Sulphur compound freeze-out in LNG production
2. Impurity freeze-out in LH₂ production

The outcomes of this project will allow engineers in liquefaction plants to reduce unplanned shutdowns and expensive over-design margins.

Further information:
https://www.fenex.org.au/connect/

 

September 2024