Late in the evening on April 22 and through the morning of April 23, the Limetree Bay Refinery experienced an operating upset in the sulfur processing part of the refinery. Limetree investigated and determined that this upset caused a pressure increase in some equipment, which resulted in the opening of a pressure relief valve and sent an unusually high amount of sulfur-containing gases to the flare, where they were safely burned.
The pressure relief valve and flare are designed to work this way to protect the refinery workers and community.
When the sulfur-containing gases burned in the flare, sulfur dioxide was produced. This unusually high level of sulfur dioxide coming from the flare unfortunately resulted in an odor that was evident to parts of the neighboring community. Sulfur dioxide has an odor similar to a struck match and can be smelled even at a very low concentration level, which is far below the level normally considered dangerous to health.
The refinery workers took action to correct the upset condition, which eliminated the source of the bad odor by late morning April 23. After a few more hours, all traces of the odor dissipated on Friday.
Limetree Refinery further clarifies that the refinery did not experience a gas leak of hydrogen sulfide during this incident, as some media reports have indicated. Hydrogen sulfide was a component in the gases that were safely burned in the flare, generating the sulfur dioxide that resulted in the odor.
The executive management of Limetree Bay sincerely apologizes on behalf of the entire organization for the unpleasant odor that came from the refinery and its impact on neighbors and the community. We are committed to investigating fully the reasons for this event in cooperation with local regulators and to implement improvements to prevent it from happening again.
For more information or to report an issue, contact the Limetree Bay Command Center at 340-692-3000.