Light-ends fractionation train
A classic three-column light-ends train splitting an ethane/propane/ n-butane/n-pentane feed into four near-pure products: DEC2 (deethanizer, 5 bar) rejects ethane overhead, DEC3 (depropanizer, 5 bar) takes the propane cut, and DEC4 (debutanizer, 2 bar) splits n-butane from n-pentane. A genuinely wide-boiling train — DEC2 and DEC4 both land in the documented successive-substitution residual plateau (converge to a physically correct, sharp separation just above the strict 1e-5 tolerance) rather than a clean converged status, the same class of behavior already accepted for the DME casebook entry. From the ChemSep casebook (light-ends fractionation).
The flowsheet
The solved topology — every unit op's real duty, conversion, or split, read straight off a genuine converged solve.
The stream table
Every stream's flow, temperature, pressure, and composition — real converged numbers, not placeholders.