NGL fractionation train (depropanizer + debutanizer)
The full two-column NGL fractionation train of a gas plant: a raw NGL is split into three products. The depropanizer takes a propane-and-lighter overhead (the propane product), and its C4+ bottoms feed a debutanizer that splits butane overhead from a natural-gasoline (C5+) bottoms. Both columns use the component-flow Naphtali-Sandholm MESH (method "ns") so each sharp cut conserves every component exactly; the two columns solve in sequence (no recycle) and the whole train closes on mass. Peng-Robinson handles light-hydrocarbon VLE; the debutanizer runs at a lower pressure (7 bar vs 18) so its reboiler stays within a reasonable temperature.
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.