Purge Process Flowsheets & Simulations
Explore 3 validated, solved Purge simulation flowsheets in MaximaLabs — real components: benzene, h2, cyclohexane, toluene, o_xylene, biphenyl. Open any one directly in your browser.
Solved via: PENG-ROBINSON.
Benzene hydrogenation → cyclohexane
Benzene + 3 H₂ → cyclohexane in a conversion reactor, then a high-pressure flash recovers liquid cyclohexane and recycles the excess hydrogen (with a purge). The classic ChemSep recycle example — exercises reaction + recycle convergence.
8 unit ops • PENG-ROBINSON
17 0
View & openThermal (non-catalytic) HDA — broad aromatics feedstock
A real thermal-HDA licensor's process (non-catalytic, tolerant of a mixed aromatics feedstock and inert impurities) modeled as a genuine competing-reaction network, not a fixed-Keq equilibrium reactor like the simpler hda-toluene-dealkylation example: a vapor-phase kinetic_reactor runs three simultaneous Arrhenius reactions sharing one feed pool -- the main toluene dealkylation (toluene + H2 -> benzene + methane), a coking/heavies side reaction that consumes toluene without making benzene (2 toluene -> biphenyl + H2, the real reaction that caps aromatic yield below 100% and drives decoking intervals), and a lumped xylene dealkylation (o-xylene + 2 H2 -> benzene + 2 methane, a single-step simplification of the real toluene-intermediate pathway) standing in for the broader C8/C9 aromatics this technology also processes. H2S/CO2/ammonia ride through the flowsheet as inert impurities -- exactly what 'impurity tolerance' means in a mass balance, not a special chemistry path. The H2-rich high-pressure separator vapor is a real recycle loop, not a once-through vent: fresh feed joins recycled gas at a mixer ahead of the reactor, and past the separator the vapor splits into a recompressed recycle (92%) and a purge (8%) that bleeds off the methane a single pass could never consume -- the actual reason a real HDA unit needs a purge, same role it plays in the ammonia-synthesis-loop example. Quench, the high-pressure separator, and a letdown-valve-plus-flash stabilizer strip dissolved H2/methane before the aromatics split. The final benzene/xylene-derived-benzene/toluene split still uses a shortcut separator rather than a rigorous column, for the same documented reason (hda-toluene-dealkylation's own description): trace H2/methane corrupts the column's wide-boiling initial-guess classification, and a fix narrowed to just that seed broke the shipped methanol-synthesis example when tried previously. Kinetics here are illustrative order-of-magnitude Arrhenius parameters (not a literature fit to a named source), tuned so the reported yield/selectivity is a genuine emergent result of the reaction network competing for feed -- not a fabricated match to any specific licensor's published purity/yield figures.
14 unit ops • PENG-ROBINSON
17 0
View & openAmmonia synthesis loop (Haber-Bosch, ChemSep casebook)
The classic industrial ammonia loop: fresh syngas joins recycled unconverted gas, reacts over an equilibrium reactor (N₂ + 3H₂ ⇌ 2NH₃) at synthesis conditions, is chilled to condense high-purity liquid ammonia, and the remaining vapor splits into a recycle (back to the loop) and a purge — the purge exists specifically to bleed off the inert argon a single-pass reactor could never consume, which would otherwise concentrate in the recycle forever.
9 unit ops • PENG-ROBINSON
17 0
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