Low-capital Crude Unit Revamp Increases Product Yield
SUMMARY
Crude unit revamps can sometimes yield large economic improvements with low-capital investment. In this case study, improving atmospheric crude column stripping section efficiency improved diesel yields and unloaded the downstream vacuum column ejectors, increasing VGO yield. The low-capital modifications made in this revamp had a simple payout of less than 2 months.
TEXT
In 2001, Lyondell-Citgo Refining LP improved diesel yield by 4.8% and atmospheric gas oil (AGO) product yield by 0.5% on whole crude by implementing a low-capital cost revamp in its Houston refinery.
Lyondell-Citgo produces more gas oil than its FCC can process; therefore, the crude revamp enabled the refiner to upgrade higher-sulfur vacuum gas oil to diesel at an average of $2.50/bbl.
Before the revamp, tray fouling in the atmospheric column stripping section forced Lyondell-Citgo to lower the steam rate as the run-length progressed to avoid atmospheric tower bottoms (ATB) entrainment…