Declining Diesel Recovery

As a result of increased bottoms yield in their supply of crude (purchased crude becoming progressively heavier), the client’s diesel recovery from gas oil progressively declined, resulting in incremental diesel being downgraded to 6 Oil.

 Heat Recovery Feature

Polaris provided a Revamp that allowed the refinery to efficiently recover lost diesel yield and exceed the previous overall plant diesel recovery performance. The Revamp consisted of a grass roots 30 MBPD Vacuum Distillation Unit (VDU).  This unit received gas oil feed from two existing Crude Distillation Units (CDU). An important feature of this revamp was the recovery of heat from the VDU products into the CDU feed.  Crossing battery limits for heat integration is an uncommon innovation but resulted in additional lift for the upstream Crude Units which had been previously constrained.

New Low Sulfur Vacuum Gas Oil (LSVGO) Product

As a result of the new heat integration, additional lift was available in the CDUs enabling the units to improve the diesel recovery from gas oil directly in the CDUs.  The CDU gas oil was then processed further in the downstream VDU to recover all the remaining diesel from gas oil and produce a new, Low Sulfur Vacuum Gas Oil (LSVGO) product, further increasing the profitability of the refinery.

Scope of Work

Process / Chemical




Refining, Oil & Gas