Introductory Remarks

High capacity trays have been available for many years. Distillation practitioners understand the unique intricacies of each offering; but many in the industry don’t. When applying a high capacity tray device, it is important to understand both their strengths and weaknesses.

On small columns, applying high capacity trays required the practitioner to settle on which variable was more important for their system: capacity or efficiency. Many times to gain efficiency, more standard cross-flow trays were utilized as using a tray with more weir length would reduce efficiency.

The authors will share a case study of a recent application where a Debutanizer tower was revamped from traditional trays to high capacity trays. As the tower rectification section was not as liquid loaded as the stripping section, Parallel Flow MD trays were utilized. Revamp results show that PFMD trays transition the gap between a cross-flow and counter-flow efficiency; without a large loss in efficiency.