Diesel hydrotreater with closed H2 recycle + amine wash — a PENG-ROBINSON process flowsheet
Diesel (an n-hexadecane carrier with a dibenzothiophene sulfur slice) and hydrogen react over a trickle-bed-equivalent reactor (dibenzothiophene + 3H2 → biphenyl + H₂S, the real HDS desulfurization route) after a fired-heater preheat. Hot and cold high-pressure separators knock the light gas off the treated oil; an amine wash (a fixed-recovery separator — the same simplification the existing carbon-capture example uses, not a full electrolyte amine model) scrubs H₂S from the recycle gas before a compressor closes the loop back to the reactor feed, with a small purge controlling buildup. A pressure-letdown valve + stripper finish the treated oil, removing dissolved light ends before the desulfurized diesel leaves the bottoms.
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- Rigorous PENG-ROBINSON thermodynamics, solved by the same engine every simulation runs on.
- 9 unit operations modeled: 2× Liquid MIX, 2× COOL, HDT Reactor, 2× COLD HP SEP, Amine Absorber, Recycle Split, Recycle COMP, Letdown, Stripper.
- Focus areas: Hydrotreating, Desulfurization, H2 recycle, Amine treating, Recycle.
- Thermodynamics
- PENG-ROBINSON
- Components
- n_hexadecane, dibenzothiophene, biphenyl, h2, h2s
- Unit operations
- 2× Liquid MIX2× COOLHDT Reactor2× COLD HP SEPAmine AbsorberRecycle SplitRecycle COMPLetdownStripper
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("refinery-hydrotreater")
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
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.
Helium liquefaction (Linde-Hampson cycle)
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.
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.
Propane refrigeration cycle
A single-stage vapor-compression refrigeration loop: propane vapor is compressed, condensed to subcooled liquid, throttled through a valve, and superheated back to vapor in the evaporator before recycling — a small makeup feed and purge close the mass balance (inspired by ChemSep's Refrigeration_* reference cases).
Ammonia refrigeration cycle
A single-stage vapor-compression refrigeration loop using ammonia — the classic industrial (rather than HFC) refrigerant — condensed to subcooled liquid, throttled through a valve, and superheated back to vapor in the evaporator before recycling (inspired by ChemSep's Refrigeration_Ammonia-30C reference case).