Described by Marathon Petroleum Co. (MPC) as a Residual Oil Upgrade Expansion, or ROUX, the $2.5-billion capital investment would enable the company to convert heavy residual oil into approximately 1.2 million gpd of ultra-low-sulfur diesel at the Garyville refinery.

The ROUX project would follow MPC’s $3.9-billion refinery expansion in Garyville, which represented one of the largest manufacturing projects in Louisiana history upon its completion in late 2009. Since that time, the Garyville refinery doubled its refining capacity to 522,000 bpd and is now the third largest US refinery.

After completing feasibility studies, MPC expects to make a final decision on the project by early 2015. If approved, the project includes new hydrotreating, hydrocracking and desulfurization units, along with additional infrastructure such as buildings, tanks, cooling towers, and rail and electrical facilities.

The project would provide additional 304 new indirect jobs, for a total of more than 360 new jobs.

MPC estimates development of the project will provide 3,000 new construction jobs during the multiyear construction phase. The new jobs are an addition to the refinery’s existing workforce of 800 Marathon Petroleum employees and 650 contract workers.

“As part of the ongoing feasibility study, Marathon Petroleum is pleased to be taking this next step of submitting the permit applications for the Residual Oil Upgrade Expansion at our Garyville facility,” said Rich Bedell, the company’s senior vice president for refining. “We have been diligently working with the state and local officials concerning the various milestones for a project of this size. If the company decides to move forward, it is anticipated that the construction would begin mid-2015 and to be completed in 2018.”

MPC is the nation’s fourth-largest refiner, with a crude oil refining capacity of approximately 1.7 million bpd in its seven-refinery system.