A hydrogen explosion and fire occurred in the benzene unit of a styrene plant in a large petrochemical complex. The unit was being restarted following a scheduled maintenance shutdown. The explosion followed the release of about 30 kilograms of 700-psig hydrogen gas from a burst flange into a compressor shed. Two men were killed and two others were injured. If it had not been a holiday, the death toll and injuries would probably have been much worse.
A significant hydrogen leak occurred during refueling of the onboard hydrogen storage tank of a fuel cell-powered lift truck while it was completely depowered. The in-tank shutoff solenoid valve had recently been replaced, and this was the initial refueling event after the replacement. The fuel zone access panel was removed to allow constant visual leak checking with Snoop leak-detection fluid. The event occurred during the final pressure testing of the repaired system when an O-ring failed at approximately 4500 psi, releasing the entire contents of the hydrogen tank in about 10 minutes.
A pressure relief device (PRD) valve failed on a high-pressure storage tube at a hydrogen fueling station, causing the release of approximately 300 kilograms of hydrogen gas. The gas ignited at the exit of the vent pipe and burned for 2-1/2 hours until technicians were permitted by the local fire department to enter the station and stop the flow of gas. During this incident the fire department evacuated nearby businesses and an elementary school, closed adjacent streets, and ordered a high school to shelter in place.
As part of preparing for material disposal, a small fire occurred within a fume hood as a researcher was combining several spent ammonia borane (AB) samples that had previously been stored uncovered in the back of the hood for 6+ months. These AB samples consisted primarily of two 40-gram products of a 50wt% AB in silicone oil that had been thermally dehydrogenated. A small amount of unreacted AB slurry is believed to also have been present.