Hydrogen fire in a food industry

A jet fire occurred on a 25m3 hydrogen storage tank while transferring a catalyst to a buffer tank.

The constabulary created an area of safety around the plant while the staff extinguishes the fire by purging the tank with nitrogen. The fire is extinguished prior to the arrival of fire brigade.

The INITIATING cause could ave been a catalytic ignition of hydrogen.
Thetranfer operation to the buffer tank was not foreseeing inertisation of the tank atmosphere. This shortcoming in hazards prevention procedures could be the ROOT CAUSE .

tank, catalyst

The hydrogen fire occurred when transferring a catalyst into a buffer tank.

Firefighters’ took up positions within feet of the burning trailer, to douse the fire and cool cylinders with water hoses. The incident commander decided to launch an offensive attack on the fire was made to prevent loss of life should the cylinders catastrophically fail because he recognized there was little chance of a timely evacuation in the highly congested area. Firefighters later established monitor nozzles to cool the hydrogen cylinders from a safer distance.
Soon after first responders arrived, one of the PRDs actuated. The most intense gas venting lasted for about 30 to 45 minutes. With a reduction in venting intensity, responders believed the risk of catastrophic cylinder failure had diminished.
The truck driver remained on the scene to further inform emergency responders until the moment the company site manager and the company recovery team arrived almost 1 hour after the incident began. The manager encouraged the incident commander to continue the cylinder cooling efforts with water spray to prevent the fire from involving additional cylinders.
The incident was managed with a 150-foot exclusion zone and 400–500-foot distance to the command post, the DOT Emergency Response Guidebook (ERG) Guide 115, recommends a 1-mile isolation distance. Expanding the evacuation zone was a major goal of the response, but recommended protective distance was not practical given traffic congestion in the area.

After a 30-minute cycle of water spray cooling followed by thermal imaging inspection, firefighters detected a persistent heat signature in the module that kept this process continuing throughout the evening. Company technicians were unable to access the module until 10:00 p.m., about 9 hours after the incident began.

The company recovery team began a controlled venting procedure for the remaining hydrogen cylinders. To accelerate the process, the team checked pressure in the remaining cylinders and vented them simultaneously. About 3:30 a.m., the scene was secured, and the company towed the empty tube trailer module beck to the storage terminal.

The NTSB investigation found the following:
"The County Fire Department emergency responders lacked familiarity with hydrogen tube trailer modules. Emergency responders did not immediately recognize the presence of hazardous materials, had difficulty estimating the likelihood for severe outcomes, and had not received guidance about appropriate mitigating actions needed to reduce the potential for catastrophic gas cylinder failures."

Following the analysis of the incident, a mdification of the procedure was decided: before transferring the to catalyst, the buffer tank must be placed under nitrogen. A non urther specified safety barrier was added on the tank.