Extractive distillation Process Flowsheets & Simulations
Explore 7 validated, solved Extractive distillation simulation flowsheets in MaximaLabs — real components: methylcyclohexane, toluene, phenol, benzene, sulfolane, acetic_acid. Open any one directly in your browser.
Solved via: PENG-ROBINSON, NRTL.
MCHT extractive distillation with phenol
Extractive distillation of methylcyclohexane (MCH) and toluene using phenol as the selective solvent, adapted from Tiverios and Van Brunt (Ind. Eng. Chem. Res. 2000, 39, 1614). Phenol raises toluene's relative volatility away from MCH enough to split an otherwise close-boiling pair; a solvent-recovery column then splits toluene from the phenol (reported as its own product rather than recycled).
7 unit ops • PENG-ROBINSON
17 0
View & openSulfolane extractive distillation of aromatics
Extractive distillation recovering benzene and toluene from a stabilized reformate's C6-C7 non-aromatics (represented by methylcyclohexane) using sulfolane, after Figure 10.2/10.6 of T. Brouwer (PhD thesis, TU Twente, 2021). A vacuum solvent-recovery column then splits the aromatics from the sulfolane (reported as its own product rather than recycled). Note: the extractive column (ED) does not fully converge within the solver's iteration cap for this 4-component polar/nonpolar system and returns a partial profile — shown for the process topology rather than as a converged reference case.
7 unit ops • PENG-ROBINSON
17 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.
7 unit ops • PENG-ROBINSON
17 0
View & openExtractive distillation (ethanol/water with ethylene glycol)
Near-azeotropic ethanol/water (85 mol% ethanol) can't be pushed past the 89 mol% azeotrope by ordinary distillation. A heavy, high-boiling entrainer (ethylene glycol) fed near the top of the column raises water's relative volatility enough to pull overhead ethanol past the azeotrope in one pass; a second column then strips water overhead from the glycol, regenerating it as the bottoms product. The classic extractive-distillation textbook case (Luyben, Ind. Eng. Chem. Res. 2006, 45, 4625).
7 unit ops • NRTL
19 0
View & openCO2/ethane extractive distillation with n-decane
CO2 and ethane are close-boiling (both around 195 K at 1 atm) and form a near-azeotropic VLE at NGL-processing pressures, a known problem for straight distillation in CO2-flood-associated gas and acid-gas-rich NGL streams. A heavy n-decane solvent shifts CO2's relative volatility enough to take it overhead in far fewer stages than an ordinary deethanizer would need; a second column then strips the solvent from the ethane bottoms for recycle. The extractive column runs at a moderately high reflux (R=4.5) — the operating point a genuinely close-boiling pair needs to hold a sharp CO2/ethane split with a heavy solvent — and both columns converge.
7 unit ops • PENG-ROBINSON
17 0
View & openWaste solvent recovery — extractive distillation (IPA/water)
A pharmaceutical waste isopropanol/water stream (near the ~68 mol% IPA azeotrope) is fed to an extractive column with a high-boiling entrainer feeding in a few stages above it; a second column strips the entrainer back out of the bottoms for reuse. Honesty note: the brief's original entrainer, DMSO, doesn't have a pinned NRTL isopropanol binary in this codebase's databank (only DMSO-water is pinned), so this uses sulfolane instead — a real, industrially-standard extractive/physical solvent with a genuine pinned NRTL isopropanol binary. At this stage count and solvent-to-feed ratio the entrainer effect is real but modest (overhead reaches ~82 mol% IPA, up from the 68% feed) — a sharper, near-anhydrous cut would need more stages/reflux or a higher solvent ratio than what this session verified converges reliably.
7 unit ops • NRTL
18 0
View & openAnhydrous ethanol — extractive distillation past the azeotrope (NRTL)
Producing fuel-grade anhydrous ethanol from a near-azeotropic ethanol/water feed using ethylene glycol as the extractive entrainer. Ordinary distillation is capped at the 89.4 mol% ethanol azeotrope; the high-boiling glycol raises water's relative volatility so ethanol crosses its azeotrope and leaves the extractive column essentially pure, while a vacuum solvent-recovery column strips the water and recycles the glycol. This is modeled with the NRTL activity package on pinned DECHEMA binaries for every pair (ethanol/water, ethanol/glycol, water/glycol) — the non-ideal, azeotrope-crossing VLE a cubic equation of state structurally cannot reproduce (Peng-Robinson stays trapped at the ~89% azeotrope). Honesty note: NRTL binaries come from the bundled DECHEMA VLE Data Collection (via ChemSep/DWSIM), not fitted here; the solvent-recovery column runs under vacuum to keep the glycol below its decomposition temperature.
7 unit ops • NRTL
19 0
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