Helium liquefaction (Linde-Hampson cycle) — a COOLPROP process flowsheet
A Joule-Thomson liquefaction loop: helium is compressed, aftercooled, precooled well below its ~40-51 K JT-inversion temperature, then throttled through a valve into a flash drum that draws off liquid helium while the cold vapor recycles back to the compressor suction — the same JT-cycle physics as the platform's LNG/refrigeration loops, run on a fluid whose inversion curve makes precooling mandatory before the throttle can cool it at all.
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- Rigorous COOLPROP thermodynamics, solved by the same engine every simulation runs on.
- 5 unit operations modeled: MIX, COMP, 2× Precool, JT, Flash.
- Focus areas: Helium liquefaction, Cryogenics, Joule-Thomson, Linde-Hampson cycle, Recycle.
- Thermodynamics
- COOLPROP
- Components
- helium
- Unit operations
- MIXCOMP2× PrecoolJTFlash
Opens in a new tab, loaded straight into the app — no setup.
Read the step-by-step guideReproduce this exact result from Python — the real client.get_example() → run_and_wait() path, not a mockup.
from flowsim.sdk import FlowSimClient
client = FlowSimClient()
example = client.get_example("helium-liquefaction")
sim = client.create_simulation(example["title"], example["flowsheet"])
result = client.run_and_wait(sim["id"])
print(result["status"]) # "converged"
streams = client.streams(sim["id"])Related models
Hydrogen liquefaction with catalytic ortho-para conversion
A Linde-Hampson JT-cycle liquefaction loop for H₂ (the same recycle topology as helium-liquefaction), but H₂'s real liquefaction process needs one more step helium doesn't: normal H₂ feed is ~75% ortho-/25% para-spin-isomer, while the equilibrium mix at liquid-H₂ temperature is ~99.8% para — liquefying without converting first leaves the ortho fraction far above its new equilibrium value, and its slow natural relaxation releases heat (the textbook explanation for uncatalyzed LH2 tanks self-boiling). This closes a real gap: ` (a catalytic cold-box converter, real equilibrium-para-fraction statistical mechanics) existed in MaximaLabs but was never wired into a showcase example — and turned out to also be missing from the backend's unit-type validation catalog entirely (fixed alongside this example, in `). Precooling to 30 K (deep enough that H₂'s JT effect actually condenses it — verified numerically: 77 K/60 K/45 K precool all give zero liquid yield at 20 atm → 1.3 atm here, since H₂'s JT-cooling window needs real precooling well below LN2 temperature, unlike simpler gases) also happens to sit right where the ortho-para conversion actually matters.
LNG front end and storage: guard beds, tank boil-off, driver limit
The parts of a 5.2 Mtpa LNG train that are not the cold box, and the four questions they answer that no bulk unit can — at real capacity, so the vessel sizes and duties are ones an engineer can check against their own plant. Guard beds: a sulfur-carbon bed takes mercury from 200 to 0.01 µg/Nm³ — the brazed-aluminium limit, because mercury attacks the plate-fin cold box by liquid-metal embrittlement — on a 4.8 m x 6.6 m bed with 4.2 years of life from a capacity balance — inside the 3-5 year window these non-regenerable beds are actually replaced on, which is what a turnaround plan needs. A 4A molecular sieve then dries the gas to 0.1 ppmv, the only route to a cryogenic water spec (a glycol contactor tops out near a −30 °C dew point), on a 4.9 m x 5.1 m bed running a 13.8 h cycle for 1.3 MW of regeneration duty. Storage: the LNG goes to a tank whose boil-off rate comes from a 0.05%/day guarantee but whose boil-off composition comes from a real equilibrium flash — and that is the interesting part, because the vapour leaves at ~11 mol% nitrogen against 1.1% in the feed. Nitrogen and methane are far more volatile at 113 K, so the boil-off is light and the stored liquid weathers heavier: nobody specified that, the flash found it. Recondensing: the boil-off goes back into the send-out LNG rather than to a flare, and the unit reports the LNG:BOG ratio (1999) against the minimum the energy balance demands (3.8), which is the constraint a terminal is actually operated against. The driver: a gas turbine burning plant fuel gas, rated 97.5 MW at ISO conditions, delivers only 84.5 MW at 35 °C — 5.5 MW short of its 90 MW refrigeration load, and flagged as such. That derate is computed from two physical effects (a fixed-geometry compressor swallows a fixed volume so mass flow follows air density, and hotter air costs more to compress), not from a vendor curve, and it comes out at 0.66%/K — mid-band for industrial machines. It is why a tropical LNG train makes less product in summer.
Gas-condensate LNG train: condensate, LPG and LNG
The LNG plant that is also a liquids plant, at real capacity: this is one 4.4 Mtpa train (a two-train plant is two of these), not a scaled-down sketch. A condensate-rich field arrives by trunkline as a two-phase stream: the slug catcher drops ~20 mol% of it out as raw condensate before a single molecule reaches the cold end, and the plant then runs two trains side by side off one feed. Liquids: the raw condensate is let down to an MP flash that strips the dissolved methane (without it the stabilizer's shortcut total condenser tries to condense methane at 8 bar, which is not a real stabilizer overhead), then stabilized to a C₅/C₆ product. Gas: sweetened and dried, chilled to 245 K to knock out an NGL cut, and the NGL demethanized and split by a deethanizer / depropanizer / debutanizer sequence into commercial propane (~98 mol%) and butane (~98 mol%) LPG plus a natural-gasoline bottoms. LNG: the lean gas goes to the same APCI C3MR cold end as the 'c3mr-lng-liquefaction' showcase — propane precool, mixed-refrigerant MCHE to 120 K, JT letdown to a 1.5 bar end-flash drum. Five sold products come out of one flowsheet, each a stream the solver computed. Watch the end-flash boil-off: it leaves at ~13 mol% nitrogen against 1 mol% in the feed, because the flash drum is where an LNG train actually rejects its nitrogen — nobody specified that, the flash found it. Dehydration is the real molecular-sieve bed, not a stand-in: a 4A sieve sized by length-of-unused-bed, which is what actually takes the gas to the <=0.1 ppmv the cold box needs — 95 t of sieve on a 5.5 x 5.5 m bed, a 17.5 h cycle and 1.4 MW of regeneration duty, with 0.47 bar of Ergun pressure drop. The AGRU spec is checked against the physics rather than assumed: 99.9% CO₂ removal leaves 33 ppmv, and at the coldest point in the train (115.9 K) the solid-CO₂ solubility limit is 232 ppmv on the measured-data basis — a 7x margin, so the sweetening spec demonstrably clears freeze-out instead of merely looking tight.
High-CO2 LNG with amine capture and CO2 reinjection
One 5.3 Mtpa LNG train on a reservoir whose gas is 14 mol% CO₂, where the CO₂ is not vented but compressed to dense phase and injected — 2.8 Mtpa of it, at 200 bar, which is the scale that makes this a storage project rather than a gesture. Two things make this different from every other LNG example here. First, the acid-gas removal is real chemistry, in the same flowsheet as the cryogenics: per-node thermo_overrides run the absorber, the rich/lean loop and the stripper on the 'enrtl-mdea-pz' electrolyte package (MDEA protonation + piperazine carbamate/dicarbamate speciation) while the gas train and the cold end run Peng-Robinson — the amine unit and the MCHE are not two models bolted together, they are one solve. Second, the CO₂ goes somewhere: the stripper overhead is knocked back, two-stage compressed with interstage cooling and drying, and pumped to 200 bar as a ~96 mol% dense-phase stream ready for a reinjection well, rather than leaving as a vent. The sweet gas is water-washed, dried and liquefied in the C3MR cold end to LNG at ~116 K.
LOHC hydrogen release (methylcyclohexane dehydrogenation)
A liquid organic hydrogen carrier (LOHC) power train: methylcyclohexane (MCH) is preheated and catalytically dehydrogenated (MCH → toluene + 3H2, endothermic, equilibrium-limited to ~90% single-pass conversion) to release hydrogen for downstream power generation. A flash drum separates the H₂-rich gas from the liquid; a distillation column then recovers the unreacted MCH overhead and recycles it to the reactor feed, closing a real tight liquid recycle loop, while spent toluene leaves the bottoms (to be re-hydrogenated back to MCH off-site, closing the supply-chain loop — out of scope for this dehydrogenation-side flowsheet). Screening-fidelity note: MCH and toluene are genuinely close-boiling (relative volatility ~1.4 under this thermo package at column conditions), so the recycle carries real toluene along with the recovered MCH rather than a sharp cut — a production column would use more stages to purify it further; this shows the recycle topology and its convergence, not an optimized column design.
Recycle loop
A mixer/heater/splitter loop with a tear stream — exercises Wegstein recycle convergence.