Innovative Emissions Reduction in Washington State Wins Award

• A construction industry association recognized Marathon Petroleum’s Anacortes, Washington, refinery with an award for the best private-sector project of 2023 under $10 million.
• The Northwest Construction Consumer Council honored a refinery initiative to reduce emissions of nitrogen oxides (NOx), noting its innovation, safety and efficient completion.
• The refinery applied for a U.S. utility patent in relation to the project, which has the equivalent impact on NOx emissions of removing 180,000 light-duty vehicles from the road a year.

Removing 180,000 light-duty vehicles from the road every year. This is the equivalent impact on emissions of nitrogen oxides (NOx) from an effort in Washington state that the Northwest Construction Consumer Council (NWCCC) recently honored as the best private-sector project of 2023 under $10 million. The initiative at Marathon Petroleum Corporation’s (MPC) Anacortes refinery incorporated selective non-catalytic reduction (SNCR) technology at the site to decrease NOx emissions.

“This project exceeded our expectations by achieving a 31% reduction in NOx emissions, which amounts to 321 tons per year,” said MPC Process Engineer David Rudd. “We used computational fluid dynamics modeling to arrange chemical reactions that accomplish NOx destruction.”

Using ammonia from a specific refinery waste stream for this purpose represents what is believed to be a refining industry first.

The project focused on one of the two carbon monoxide (CO) boilers in the Anacortes refinery’s fluid catalytic cracking unit. Infrastructure was added to reroute ammonia that comes from another refining process for injection into the CO boiler’s firebox. This allows the ammonia to react with oxygen and NOx to produce nitrogen and water vapor, resulting in lower emissions.

Using ammonia from a specific refinery waste stream for this purpose represents what is believed to be a refining industry first. This approach also served as the basis of the refinery’s application for a U.S. utility patent, which is pending.

“In addition to innovation, the NWCCC recognized this effort for being safe, on time and under budget,” said MPC Engineering Supervisor Zac Nightingale. “It was a highly efficient use of resources, especially in light of comparable emissions-reduction methods that could cost 10 to 20 times as much to implement.”

Completing the project required collaboration inside and outside the refinery. The site’s technical services and environmental departments worked together along with contractors who provided engineering support and instrumentation and electrical services as well as carried out construction. The Anacortes refinery is exploring plans to install a similar SNCR injection system on the second CO boiler in the future.