Environmental protection

ConocoPhillips installs desulfurization unit at Lake Charles refinery

By Karla Wall

Mechanical construction is under way on a gasoline desulfurization unit at ConocoPhillips' Lake Charles refinery. The new unit will ultimately help the plant meet 2006 EPA gasoline sulfur content regulations well ahead of schedule.

The facility, which will utilize ConocoPhillips' own "S Zorb" sulfur removal technology, will be operational in the fourth quarter and will enable the refinery to reduce the gasoline pool sulfur content to 30 parts per million under the new EPA regulations. The current average gasoline sulfur content is 200 ppm.

This is the third S Zorb sulfur removal unit to be built inside the ConocoPhillips refining system, with one more currently planned.

The S Zorb technology utilizes a proprietary sorbent that extracts sulfur from the gasoline. The process is unique in that it can reduce sulfur levels to below 10 ppm without the resulting loss of volume or octane that is associated with other gasoline desulfurization processes.

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The current work requires both Inside Battery Limits (ISBL) and Outside Battery Limits (OSBL) construction.

Burns & McDonnell Engineering of Kansas City, Kan., and Fluor Corp. of Pasadena, Calif., have been designing the OSBL and ISBL work, respectively, for more than a year. Performance Contractors of Baton Rouge was awarded the ISBL civil portion of the project, as well as the ISBL and OSBL mechanical portions.

Burns & McDonnell is providing construction management.

Performance site manager Steve Stark said the project's greatest obstacle has been coordinating the variety of machinery, equipment and personnel in a limited space. A crew of about 225 will be working at the site.

"We're in a congested area and there's a lot of activity going on," Stark added. "It takes a lot of coordination and communication." Weekly coordination meetings are held with Burns & McDonnell and ConocoPhillips management.

The contractor must also work in an operating plant around existing process equipment, process lines and machinery.

"We've had a very good relationship with Burns & McDonnell and ConocoPhillips," Stark said. "They've done a great job of communicating with us and keeping us informed of plant activities that might affect our work activities."

Performance was provided with a schedule of the plant's shutdowns so that work on the project could be coordinated with the plant's shutdowns and turnarounds.

Safety is the top concern for Performance, Burns & McDonnell and ConocoPhillips.

"We have daily safety meetings for Performance and weekly safety meetings for ConocoPhillips," Stark added. "To date, we've experienced zero recordable incidents and no lost workdays, and our goal is to complete the project with this same safety performance."

When the project began last summer, Performance removed existing machinery and equipment from the site. Two areas measuring 125 ft. by 55 ft. and 215 ft. by 75 ft. were dug to depths of 7.5 ft. and 4 ft., respectively, and about 3,000 cu. yds. of soil were excavated. Existing concrete piles were demolished using jackhammers and mini-trackhoes equipped with breakers.

About 315 auger cast pilings lined with reinforcing steel were then installed as foundation.

"It was June, so the heat and humidity were major safety concerns for our craftspeople working in the excavations," said Stark. "We went to extended breaks, we had rest stations set up by the work locations and ConocoPhillips provided water-cooled fans for the site."

Stark said the foundations and area paving were poured using 2,100 cu. yds. of concrete and more than 140 tons of rebar.

The ISBL portion of the project requires 580 tons of steel, all erected by Performance with a 200-ton crawler crane to lift equipment. Fireproofed steel columns used in the job measure up to 20 ft. in length and weigh up to 10,000 lbs.

More than 110 pieces of equipment are being installed, including a 123-ft.-tall reactor where the sulfur removal will take place. The reactor was shipped by rail from Emporia, Kan.

Other installations include 23 new pumps to be used for various processes, two new tanks, 24 shell and tube heat exchangers to connect new and existing equipment, and a new flare stack.

About 85,000 ft. of pipe will be installed to link the ISBL and OSBL portions of the project.