Cyclic process Process Flowsheets & Simulations
Explore 2 validated, solved Cyclic process simulation flowsheets in MaximaLabs — real components: h2, co2, n2, oxygen, argon. Open any one directly in your browser.
Solved via: PENG-ROBINSON.
Pressure Swing Adsorption — H2 purification
A 5 bar shift-gas feed (H2/CO2, the dominant impurity leaving a steam-methane-reforming shift reactor) is purified across a real cyclic 2-bed PSA unit: while one bed adsorbs CO2 at high pressure (delivering H2-rich product), the other regenerates at low pressure, swept countercurrently by a slipstream of that product to desorb CO2 out the feed end as tail gas — the genuine Skarstrom-cycle mechanism, not a fixed-recovery shortcut. The solver runs the real cyclic transient (tanks-in-series bed discretization + linear-driving-force adsorption kinetics toward the same competitive-Langmuir isotherm unitops/adsorption.py uses) to a periodic steady state. Honesty notes: (1) this is a bounded 2-bed, 2-step v1 — a real industrial H2-PSA train uses 4+ beds and separate depressurization/purge/repressurization steps (interbed pressure equalization in particular recovers a lot of the efficiency this v1 doesn't capture); (2) the CO2 Langmuir isotherm is screening-order (a defensible physical magnitude for CO2 on activated carbon/zeolite near ambient T), not fitted to one cited adsorbent's published isotherm; (3) other real shift-gas impurities (CH4, CO, N2) aren't modeled, only the dominant CO2 — see flowsim/dynamics/psa.py's module docstring for the complete scope.
4 unit ops • PENG-ROBINSON
19 0
View & openOn-site oxygen: multi-bed vacuum pressure swing adsorption (VPSA)
Medical- / green-steel-grade oxygen generated on site from air by a 4-bed vacuum pressure swing adsorption unit over an N₂-selective zeolite (LiX/13X). This uses the native VPSA unit op — the proven 2-bed Skarstrom engine generalized to N beds with pressure-equalization steps and sub-atmospheric evacuation: nitrogen is adsorbed while oxygen passes as the light product, then each bed is pulled to a vacuum to desorb the nitrogen tail gas. The solver runs the real cyclic transient (tanks-in-series bed discretization + linear-driving-force kinetics + inter-bed equalization) to a periodic steady state — the transient dynamic equilibrium legacy steady-state simulators cannot capture without a separate dynamic license. Honesty note: isothermal (no heat of adsorption, which is real and significant for N₂ on zeolite); only N₂ is modeled as adsorbing, so O₂ and argon pass together — which is why the product tops out near 93% O₂ (argon co-produces with oxygen), not fabricated pure O₂; p_low is a specified vacuum boundary, not a vacuum-pump curve.
4 unit ops • PENG-ROBINSON
18 0
View & open