Fast-tracking an FCC Revamp
SUMMARY
The design, detailed engineering and installation of one revamp took just four-and-a-half months. Unit feed rate, product recovery and product quality objectives were all met after the revamp.
TEXT
In 2003 Navajo Refining Company revamped its FCC to increase capacity from 18 Mbpd to 25 Mbpd. During the previous turnaround the reactorregenerator section had been modified to meet the 25 Mbpd feed rate, but downstream equipment had not been upgraded. Such upgrading is the subject of this paper. There was only 4.5 months from engineering kick-off to unit start-up. Everything had to be done on a fast track. Consequently identifying modified or new long lead time items quickly, such as compressor rotor modifications or vessels, was top priority. Normal linear engineering practices including finalized simulations, heat and material balances and equipment specification prior to issuing bids could not be followed. In spite of the challenges the unit started up on schedule, has been able to exceed its design feed rate, and increase gasoline and LCO product recovery. Payout was less than 6 months.
Today it is not unusual for revamp projects to take 2-3 years to engineer and construct. But with a dedicated project team and experienced revamp group it is possible to complete fast track work on schedule and within budget. When this project was executed refinery margins were tight and capital was scarce, hence the decision to invest was made as near as possible to the upcoming turnaround. However, fast track does not mean wasting money. Executing fast track revamps properly avoids excessive engineering costs associated with studying options that aren’t practical. In this example, options that did not make sense were eliminated by discussions with process, project, mechanical and operating personnel with a vested interest in the successful outcome. Other time consuming activities such as drawing approvals were done in one or two days versus weeks by an appropriate working level team. Avoiding bureaucratic project execution processes eliminates waste, unnecessary costs and scheduling delays.
Developing a complete scope of work was key to preparing a good estimate and controlling costs. Fast-track revamps are challenging, because engineering activities need to be prioritized around long lead-time equipment, and standard engineering practices often...