Extraction column simulation

feed + solvent -> extract + raffinate (countercurrent LLE)

Governing equations

The exact equations the solver works for a extraction column — the same math shown in the app's "Theory" panel, not a black box.

$K_D$

distribution coefficient — solute concentration in the extract over the raffinate; the driving force of the whole separation

$S$

solvent (extract-phase) molar flow [mol/s]

$R$

carrier (raffinate-phase) molar flow [mol/s]

$E$

extraction factor K_D·S/R — the analog of the absorber's A; >1 favours the solvent

$N$

number of equilibrium stages

$r_j$

solute molar flow leaving stage j in the raffinate [mol/s]

$r_0$

solute fed to the cascade [mol/s]

$r_N$

solute left unrecovered in the final raffinate [mol/s]

Parameters

n_stages [int >=1], distribution_coefficients {solute: K_D = extract/raffinate ratio}, pressure/temperature [optional] — two inlets (feed, solvent) -> extract + raffinate. Countercurrent LLE cascade; recovery rises with stages (Kremser limit at constant K_D)

Example flowsheets that use it