Crude distillation (CDU) simulation

1 crude feed -> distillate + side cuts + bottoms (in order)

Governing equations

The exact equations the solver works for a crude distillation (cdu) — the same math shown in the app's "Theory" panel, not a black box.

$F$

crude feed molar flow [mol/s]

$D$

overhead distillate flow [mol/s]

$B$

bottoms (residue) flow [mol/s]

$\text{cut}_k$

side-draw product k (kerosene, diesel, gas oil…) [mol/s]

$j_k$

tray the cut is drawn from — cuts come out volatility-ordered because their trays are

$x_{i,draw_k}$

liquid mole fraction of i on that draw tray

$x_{i,bot}$

liquid mole fraction of i in the bottoms

$\Delta_{balance}$

the per-component error the default carve knowingly leaves open — set rigorous_draws=True to close it

Parameters

n_stages, feed_stage, reflux_ratio, distillate_to_feed [0..1], pressure [Pa], side_draws [[{stage, fraction}] — liquid cuts taken at trays between feed and top; distillate+draws fractions must sum < 1]. Outlets/edges in order: distillate, cuts…, bottoms. Use with petroleum-cut components / pseudocomponents under peng-robinson.

Example flowsheets that use it