Butene/isobutane alkylation — a PENG-ROBINSON process flowsheet
Sulfuric-acid alkylation of butene with excess isobutane produces high-octane alkylate gasoline blendstock; a conversion reactor stands in for the acid-catalyzed carbocation chemistry (a literal acid/hydrocarbon settler would need H₂SO₄ electrolyte thermodynamics this package doesn't carry — out of scope, same as the reactor already being a stand-in for the chemistry itself), and a deisobutanizer-style column recovers unreacted isobutane overhead. The high isobutane:olefin ratio real alkylation units run is maintained almost entirely by recycling that isobutane back to the reactor feed — closed here as a real Wegstein-converged tear loop, with only a small makeup feed replacing what the reaction actually consumes, rather than the previous version's isobutane leaving as an unrecycled product. Luyben, Principles and Case Studies of Simultaneous Design, Wiley (2011); Ind. Eng. Chem. Res. 2009, 48, 11081.
167 views 0 forks
- Rigorous PENG-ROBINSON thermodynamics, solved by the same engine every simulation runs on.
- 3 unit operations modeled: MIX, RXN, DIB.
- Focus areas: Alkylation, Reactor, Gasoline blending, Recycle.
- Thermodynamics
- PENG-ROBINSON
- Components
- 1_butene, isobutane, 2_2_4_trimethylpentane
- Unit operations
- MIXRXNDIB
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("butene-isobutane-alkylation")
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
Cumene production (benzene alkylation)
Benzene and propylene alkylate over a fixed-conversion reactor to cumene (isopropylbenzene, the feedstock for phenol/acetone via the Hock process); a downstream column recovers unreacted benzene overhead for recycle-quality purity while cumene leaves the bottoms. Luyben, Ind. Eng. Chem. Res. 2010, 49, 719.
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.
Hydrocracking reaction section
A refinery hydrocracker: heavy VGO (modeled as n-dodecane) plus excess H₂ is cracked over catalyst into lighter products via a discrete lumped first-order kinetic network, then flashed to knock out recycle H₂/light gas from the liquid product (Peng-Robinson). Conversion is set by reactor temperature and LHSV.
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).