The U.S. Chemical Safety and Hazard Investigation Board (CSB) released a new safety video Oct. 27 about the fire, explosions and hydrofluoric acid (HF) release at the Philadelphia Energy Solutions refinery.
This incident occurred at the refinery in Philadelphia, Pennsylvania, on June 21, 2019, causing the release of more than 5,000 pounds of highly toxic HF and launching a 38,000-pound vessel fragment off-site.
The fire and explosion resulted in five injured employees and $750 million in damages. A CSB investigation report said the incident should be a “wake-up call” to the industry regarding the use of HF in refinery alkylation units.
Catastrophic failure of pipe from corrosion
The safety video includes an animation of the sequence of events leading to the incident and includes comments from the CSB’s Interim Executive Authority Steve Owens and Lead Investigator Lauren Grim.
The video includes details on how a pipe elbow catastrophically failed due to hydrofluoric acid corrosion, which is a well-known safety hazard. This led flammable process fluid to escape through the ruptured pipe elbow. Upon release, the process fluid formed a large ground-hugging vapor cloud about 10 feet high that engulfed a portion of the refinery’s HF alkylation unit. The cloud ignited, causing the fire and series of explosions.
In its investigation report, the CSB made recommendations for finding safer alternatives to HF in the alkylation process and called for stricter requirements from the Environmental Protection Agency when it comes to the use of HF in refining processes.