(7f) Debottleneck Distillation Columns Using Dividing Wall Column Technology

This presentation explores the revamp journey of two commonly used separation sequences:

Case study 1: A sequence of Naphtha Splitters were revamped multiple times over its 15 years of life cycle. The original configuration of columns was equipped with conventional sieve trays. In the 1^st revamp the column internals were changed to high capacity packing. Though the capacity increase was more than 40%, the product specifications were compromised.

In the 2^nd revamp, an additional side cut was introduced to improve product specifications. The drawback was a reduction of top and bottom product yields.

Finally, the column was revamped to a dividing wall column. The revamp provided a capacity increase of an additional 40% over that achieved by high capacity internals. There was simultaneous improvement in the product specifications and yields.

Case Study 2: This case study involved an indirect sequence of a depropanizer followed by propylene splitter producing chemical grade propylene. The two columns were equipped with high capacity trays. Besides a 30% increase in through put, DWC revamp provided higher propylene recovery and lower RVP of bottoms C4 product used for gasoline blending.