This is the same amine (MEA) absorption-stripping loop as the 3D column model, redrawn as a loading-vs-temperature cycle diagram instead of a physical column view — the natural 2D-native way to look at a temperature-swing equilibrium process. The two curves are the Van't Hoff/Langmuir equilibrium isotherms α_eq(T) at the flue-gas CO₂ partial pressure and at the steam-diluted stripper pressure:
K(T) = K₀ · exp[ −ΔH_abs/R · (1/T − 1/T₀) ]
α_eq(T,P) = α_max · K(T)·P / (1 + K(T)·P)
The bright quadrilateral is the actual working cycle: solvent absorbs CO₂ at the cold absorber temperature (vertical rise, lean→rich), is pumped and heated to the stripper (horizontal leg, loading unchanged), desorbs CO₂ at the hot stripper temperature (vertical fall, rich→lean), then is cooled and pumped back (horizontal leg, closing the loop). Moving dots trace real amine parcels around that loop, coloured by their instantaneous loading; green flux dots on the left/right show CO₂ entering from flue gas and leaving as captured product, at rates set by the same efficiency and loading-swing numbers shown in the readouts.
- Rich loading — the isotherm value at the absorber temperature and flue-gas CO₂ partial pressure (top-left corner of the loop).
- Lean loading — the isotherm value at the stripper temperature and the diluted stripper CO₂ partial pressure (bottom-right corner of the loop).
- Capture efficiency — how much incoming CO₂ the circulating solvent can absorb, set by circulation rate × loading swing (rich − lean) against the flue-gas CO₂ load.
- Reboiler duty — sensible heat plus desorption heat; a narrow loop (small rich−lean swing, or a stripper barely hotter than the absorber) costs much more energy per tonne captured — real MEA plants run around 3–4 GJ/tonne CO₂.
Same physics, same commercial process (Boundary Dam, Petra Nova-style post-combustion capture) as the 3D column simulator — this view just puts the thermodynamics, not the plumbing, on screen.