(186b) Increase Throughput with Improved Product Specifications Using Dividing Wall Technology

Dividing wall technology is increasingly used in the industry to produce more throughput in existing columns.

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.