While the idea of history repeating itself tends to have a negative connotation, that’s not the case for Philadelphia-based Sunoco’s newest hydrotreater plant. The plant uses older, but still viable, technology and existing resources for cost effectiveness and energy savings.
Burns & McDonnell provided engineer-procure-construct services to convert Sunoco’s 50-year-old hydrocracker unit to a hydrotreater unit to produce ultra low-sulfur diesel (ULSD). After sitting idle for nearly 10 years, the unit and its accompanying hydrogen plant needed extensive inspections and evaluations to determine which components, if any, were salvageable.
“Despite some irreparable equipment, some significant pieces of equipment in the hydrocracker were functional and restorable — including corrosion-free reactors,” says Ed Edmondson, Burns & McDonnell project manager. “But the hydrogen plant had to be demolished.”
After intense testing and systematic cleaning, including asbestos and lead paint removal, the refurbished and newly installed equipment, piping and instrumentation underwent process case studies to determine optimal restart configuration. That’s when Burns & McDonnell engineers discovered the hydraulic turbine, one of the refurbished pieces of equipment, could use the high-pressure energy coming off the treated diesel to power the motor that runs the feed pump. Typically, modern hydrotreaters use electricity to power the turbine and a pressure-release valve to relieve pressure off the gas.
“This was an unexpected cost savings because it eliminated the need for electricity to power the motor,” says Steve Gucciardi, Sunoco project manager. “Burns & McDonnell really took the time and made the effort to ensure a cost-effective solution for our needs.”
Still, the hydrotreater needed hydrogen. Because the original hydrogen plant had to be demolished, Sunoco could either scrap the entire unit or build a new plant at an extremely high cost. Burns & McDonnell performed a hydrogen study and determined enough hydrogen could be extracted from other sources within the refinery to sustain the new hydrotreater, saving the cost of a new plant.
“No matter what part of the project we were in, there was always an element of discovery,” Edmondson says. “We were able to put together a team that could work through each unique discovery — and we did it with zero recordables in more than 1 million hours worked.”
The hydrotreater construction was complete in July 2009 ahead of schedule and at a cost 50 percent less than that of a newly constructed unit. This project reduces overall air pollution and lessens the environmental impact of diesel-burning vehicles, and it serves as a benchmark for similar projects.
For more information, contact Ed Edmondson, 816-822-4244.