A deisobutanizer (butane splitter) contains 80 trays. Tray efficiency is approximately 100%. Because of the close boiling points of iC4 and nC4, high reflux flow and reboiler energy are needed to...

A deisobutanizer (butane splitter) contains 80 trays. Tray efficiency is approximately 100%. Because of the close boiling points of iC4 and nC4, high reflux flow and reboiler energy are needed to achieve the required product separation. The operator is considering installation of an additional deisobutanizer. What can be changed in the new tower to lower utility consumption?