Corn wet milling: starch to high-fructose corn syrup — a SUGAR process flowsheet
The sweetener train of a corn wet mill, end to end on the new sugar thermo package. A 35 wt% starch slurry off the mill is saccharified to glucose (glucoamylase, Michaelis-Menten), part-isomerised to fructose, enriched by simulated moving-bed chromatography, and concentrated to syrup in a two-effect evaporator.
Three results are worth reading rather than assumed. The isomerase lands at 42% fructose — the real equilibrium of glucose isomerase, which is precisely why an SMB exists downstream: the reaction cannot reach HFCS-55 on its own. The SMB then splits on the cited Ca²⁺-resin affinities (fructose H=0.69 vs glucose H=0.26), sending fructose to the extract and recycling glucose in the raffinate. The evaporator finishes at 77 wt% solids, commercial HFCS syrup spec.
That last number is only reachable because of boiling-point elevation. Modelled as inert solids the sugars give no BPE feedback and the evaporator is bimodal — it either does not boil or boils to dry sugar, with nothing in between. The sugar package (Norrish) supplies the real elevation, and syrup concentration becomes a smooth, controllable function of steam (42 → 77 wt% over the sweep range). Starch itself is carried as an involatile pseudo-component: it has no boiling point to characterise, so none is invented.
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- Rigorous SUGAR thermodynamics, solved by the same engine every simulation runs on.
- 3 unit operations modeled: 2× ISOM, SMB, 2× Evap2.
- Focus areas: Corn wet milling, HFCS, SMB chromatography, Enzymatic, Evaporation.
- Thermodynamics
- SUGAR
- Components
- starch, glucose, fructose, water
- Unit operations
- 2× ISOMSMB2× Evap2
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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("corn-wet-milling-hfcs")
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-fructose corn syrup: SMB glucose/fructose separation
The single largest-volume industrial SMB in the world — separating fructose from glucose to make 55-HFCS. A glucose/fructose isomerate (dilute in water eluent) feeds the native SMB unit op; on a Ca²⁺-form ion-exchange resin fructose is the more-retained sugar, so it reports to the extract (the sweetener product) while glucose leaves in the raffinate (recycled to the isomerase reactor in a real plant). Solved as the steady-state True Moving Bed equivalent — a purely isotherm-driven liquid separation, so the sugars need no vapor-liquid-equilibrium data.
Chiral API purification: continuous SMB chromatography
A racemic active pharmaceutical ingredient (R/S enantiomers, dilute in ethanol eluent) is resolved continuously by simulated moving bed chromatography — the workhorse of chiral-drug manufacture that legacy steady-state flowsheet simulators have no native model for (engineers script it in MATLAB). This uses the native SMB unit op, which solves the standard steady-state True Moving Bed equivalent: a 4-zone counter-current equilibrium-stage cascade whose zone flow-rate ratios sit inside the triangle-theory separation region, so the more-retained enantiomer reports to the extract and the other to the raffinate — the separation is driven by the chiral adsorption selectivity (the two enantiomers are otherwise thermodynamically identical).
Phosphoric acid concentration: steam evaporator baseline (29 → 54% P2O5)
The conventional wet-process step, at the scale of one Jorf Lasfar concentration line: 138 t/h of 29% P₂O₅ acid, heated by 3.5 bar LP steam in a graphite exchanger and flashed under vacuum (0.12 bar) to 54% P₂O₅, evaporating 64.0 t/h of water. The steam feed is tuned so the concentrate lands on 54.0 wt% P₂O₅ (the user variable p2o5_wt_product), which takes 73.6 t/h of steam — 1.84 t steam per tonne of P₂O₅, 44.5 MW of condensing duty. That is the single-effect ideal; the published plant benchmark of ~2.8 t/t carries exchanger approach, losses and off-design operation on top. The point of the number here is what it costs the site: at Jorf Lasfar this steam is a co-product of the exothermic sulfuric-acid plants, which is the fact any electric alternative has to beat. Compare the two sibling examples, phosphoric-acid-concentration-microwave and -hybrid. Model scope, stated up front. The acid runs on the brine package, which carries phosphoric acid as a non-volatile molecular solute with its CRC liquid heat capacity (145 J/mol/K) — the streams show the real H₃PO₄/water compositions and the acid's sensible heat is in the balance — and a water activity fitted to measured data: binary boiling points (Li 2017, NIST TRC ThermoML Archive) and 20 °C vapour pressures up to 85 wt% (Kirk-Othmer), with a held-out error of 2% in water activity. The boiling-point elevation is therefore the fitted one, 23.5 K at 54% P₂O₅ and 0.12 bar (the ideal, Raoult's-law activity this replaced gave 9 K). Checked against a boiling point the fit never saw, it puts 85 wt% acid at 164 °C at atmospheric pressure against a measured 158 °C. Above 18 mol% acid the temperature dependence rests on one coefficient and that single check, so read the concentrate temperature to within a few kelvin. No heat of dilution is carried (about 1.5% of the latent duty at 54% P₂O₅). The 320 K feed stands in for a hotter plant feed. The acid heated at 1 atm here partly boils in the exchanger (the model's fitted boiling point at 1 atm); the real acid is kept liquid under static head and flashes in the chamber.
Enzymatic biodiesel from high-FFA waste oil (lipase)
Immobilised-lipase (e.g. Novozym 435) production of FAME from a waste feedstock — used cooking oil / rendered fat carrying ~17 mol% free fatty acid. This is the feed slate a renewable-fuels producer actually buys, and it is exactly where the conventional alkali route breaks down: NaOH or methoxide saponifies free fatty acid into soap (the databank even carries sodium palmitate), which destroys yield and emulsifies the glycerol settling step, so a high-FFA feed needs an acid-esterification pretrain before it can be base-catalysed at all. A lipase does both reactions at once and at 40 C: it transesterifies the triglyceride to esters plus glycerol, and it esterifies the free fatty acid into more product rather than losing it to soap. Both reactions are carried explicitly here, so the FFA ends up as methyl palmitate instead of as a loss. The result: 97.9 wt% ester content (EN 14214 requires >= 96.5 wt%) with the free fatty acid taken down to under 0.1 mol% of the product, i.e. a low acid value, from a feed the alkali route could not process directly. Esterification also makes one mole of water per mole of FFA converted, which is why the vacuum flash takes methanol and water overhead together — water inhibits the enzyme and has to leave the loop.
Polymerization reactor comparison: CSTR cascade vs. tubular (PFR)
The same monomer feed, split 50/50 into two trains at equal total reactor volume: a 3-stage CSTR cascade (each stage blending its own new polymer with the MWD already carried by the stream from the stage before it) versus a single tubular (PFR) reactor. Both converge to a real, different Mn/Mw/PDI — the PFR reaches higher conversion at the same total volume, but its cumulative polydispersity is measurably broader than the cascade's, because chain length drifts continuously with conversion along the tube while each CSTR stage makes its own local production under one fixed monomer concentration. See the 'Polymerization Reactors' docs page for the full reasoning.
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.