The column is fed with a vapor mixture composed of 66.66% mole of -butane (an inert component) and 33.33% mole of iso-butene and a liquid composed of pure methanol. Both feeds are introduced at stage 9. The reactive stages range from 3 to 9. The column has 16 stages, a partial reboiler, and a total condenser. The reaction taking place is the following: iso-butene + methanol ⇌ MTBE.

For low Damköhler numbers (with molar hold-up equalling zero), no MTBE is formed and the only species present in the column are -butane, iso-butene, and methanol (see first snapshot).

At moderate Damköhler numbers, we get low conversions (see second snapshot).

Finally, at high Damköhler numbers, we get almost pure MTBE as a bottom and a mixture mainly composed of -butane (88 mole %); this composition is close to the binary nonreactive azeotrope between methanol and -butane (labelled Az in the ternary diagram).