Hydrogen liquefaction, and the step helium doesn't need
A Linde-Hampson JT recycle with catalytic ortho-para conversion — without which the stored liquid boils itself away.
The actual dark-mode canvas: hydrogen compressed, cooled, catalytically converted toward the para spin isomer, then throttled and flashed to liquid — with the cold vapour returned to the compressor suction as a real closed recycle.
The conversion heat exceeds the latent heat
Normal hydrogen is ~75% ortho; at 20 K equilibrium is ~99.8% para. Liquefying first and converting later releases more heat than the latent heat of vaporization, so an unconverted tank boils itself empty. That is why a catalyst bed sits inside the cold box, and why this flowsheet models it as its own unit op rather than folding it into an efficiency.
Unit ops shipped for this vertical
Combines multiple streams into one, closing the mass and energy balance.
Polytropic compression to pipeline/process pressure.
Duty- or outlet-condition-specified energy-balance stage.
Catalytic spin-isomer shift toward equilibrium — the step that stops liquid hydrogen boiling itself away.
Isenthalpic Joule-Thomson expansion — the same relation cryogenic JT liquefaction relies on.
Single-stage vapor-liquid equilibrium split at a fixed temperature/pressure.
Stream compressor discharge, converter bed temperatures and flash-drum level from the liquefier's OPC-UA server into this flowsheet's twin comparison — an under-converted para fraction is invisible on a temperature trend and shows up weeks later as boil-off.
See the Digital Twin platform →Try it yourself
- ✓Closed Linde-Hampson recycle converged as a real loop
- ✓Conversion heat exceeds the latent heat of vaporization
- ✓The spin-isomer step modelled as its own unit op