Acetic acid Process Flowsheets & Simulations
Explore 4 validated, solved Acetic acid simulation flowsheets in MaximaLabs — real components: methanol, carbon_monoxide, acetic_acid, water, diisobutyl_ketone, ethane. Open any one directly in your browser.
Solved via: PENG-ROBINSON, NRTL, NRTL-ASSOCIATE.
Acetic acid via methanol carbonylation (Cativa process)
Methanol carbonylated with CO to acetic acid over the iridium-based Cativa catalyst (BP Chemicals), which runs at higher selectivity and lower water content than the older Monsanto rhodium process. The homogeneous catalyst itself isn't a flowing component in this model — only the carbonylation stoichiometry and downstream light-ends recovery are represented. Unreacted CO is flashed off and a column strips residual methanol from the acetic acid product.
9 unit ops • PENG-ROBINSON
227 0
View & openDilute acetic acid recovery by extractive distillation
Recovering acetic acid from a dilute aqueous stream (e.g. cellulose acetate or terephthalic acid plant wastewater) using diisobutyl ketone (DIBK) as an extractive entrainer. Because acetic acid and water form no azeotrope but have a relative volatility that flattens toward 1 as the mixture concentrates, straight distillation needs an impractically tall column and heavy reboil duty; the entrainer raises water's relative volatility so the extractive column takes water overhead in far fewer stages, and a second column then strips the entrainer from the acid bottoms for recycle. Modeled with NRTL, and the property method is the whole point here rather than a detail: an entrainer works by changing liquid non-ideality, and a cubic equation of state with van der Waals mixing has no term for it — no binary interaction parameter ships for acetic-acid/water or DIBK/water, so Peng-Robinson runs this flowsheet at kij = 0 and represents none of the effect the column depends on. It does not converge either. NRTL carries the DECHEMA-fitted acetic-acid/water binary and reaches the DIBK pairs through UNIFAC.
7 unit ops • NRTL
226 1
View & openAcetic acid recovery — NRTL with vapor-phase dimerization
Concentrating dilute aqueous acetic acid (30 mol%) by distillation, modeled with the NRTL activity package and chemical-theory vapor-phase association (acetic acid dimerizes, 2 A → A2, in the vapor). This is the physics a cubic equation of state gets wrong: the pinned NRTL acetic-acid/water binary (DECHEMA) plus the cited dimerization constants (Nagy et al., Molecules 2020) give the real bubble curve and latent heat, so the close-boiling acid/water pair actually separates and converges where Peng-Robinson does not.
4 unit ops • NRTL-ASSOCIATE
224 0
View & openOxidative dehydrogenation of ethane to ethylene + acetic acid (EDHOX concept)
Linde's EDHOX technology co-produces ethylene AND acetic acid from ethane and oxygen in one catalytic step (a proprietary mixed-metal catalyst in a multi-tubular salt-cooled reactor), with combined ethylene+acetic-acid selectivity published above 93% and the CO₂ by-product of over-oxidation recovered pure (no nitrogen dilution, since the oxidant is pure O₂, not air). Modeled here as three chained fixed-conversion reactors on real, exactly mass-balanced reactions: the main dehydrogenation (C₂H₆ + 0.5 O₂ → C₂H₄ + H₂O), the acetic-acid co-production path (C₂H₆ + 1.5 O₂ → CH₃COOH + H₂O), and a minor full-oxidation loss path (C₂H₆ + 3.5 O₂ → 2 CO₂ + 3 H₂O) accounting for the un-selective balance — the same 'illustrative, not fitted' posture as the naphtha cracker's furnace, since Linde's catalyst kinetics are proprietary and not published. The per-reaction conversions here are tuned to reproduce the one real published number (>93% combined selectivity: this flowsheet computes ~96%), not an assumed per-pass ethane conversion, which Linde doesn't publish.
10 unit ops • PENG-ROBINSON
186 0
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