Thursday, April 18, 2013

Ammonium Nitrate (not Anhydrous Ammonia) Explosion Devastates Texas Town

USAToday:
About 35 people, including 10 first responders, were killed in the Texas fertilizer company explosion Wednesday night, West Mayor Tommy Muska said in an interview with USA TODAY.
The dead include five members of the West Volunteer Fire Department who were trying to put out the initial blaze, four EMS workers and an off-duty Dallas firefighter who pitched in to help, Muska said. Not all the bodies have been recovered but all are assumed dead.
Two volunteers who showed up to help fight the blaze are also missing and presumed dead, he said.
The rest of the fatalities include residents from nearby homes in the devastated four-block area of this small north-central Texas town 80 miles south of Dallas, the mayor added.
"It's just a tragic, tragic incident," Muska said.
More than 160 others were injured.
Emergency teams went house to house through mounds of debris Thursday in hopes of finding survivors of the earthquake-like blast at the West Fertilizer Co. that sent a ball of fire and burning embers into nearby home about 8 p.m. CT.
The blast, which rocked the ground with the force of a magnitude-2.1 earthquake, could be felt as far as 45 miles away.
Officials said there was no initial indication that the blast was anything but an industrial accident, although agents from the federal Bureau of Alcohol, Tobacco, Firearms and Explosives were on the scene investigating the explosion.
The facility, which receives fertilizer by rail and distributes it to local farmers, did not have sprinklers or fire safety barriers required by state law, an official said.


A couple of notes. First, this was a fertilizer distribution facility, not a manufacturing plant. Second, they reported it was an anhydrous ammonia tank that blew up, not ammonium nitrate, which is granular. However, a 12,000 gallon tank is pretty damn big. It is really lucky that the other one didn't also blow up. Maybe the building that burned up had ammonium nitrate in it, and it blew up, but if the tank is what let loose, that was anhydrous ammonia.  Right beside one of our farms is a propane distribution plant. A couple of years ago, I came around the corner of the treeline and saw a 15 foot flame at the plant. That made me a little nervous. But they were flaring off gas as they bled down a delivery truck. When a guy from the plant was out working on my propane tank, I said something about it, and how I figured it wasn't a big deal since I saw a couple of guys standing around watching it. He said that if I saw everybody a half mile down the road, I would know something bad was happening. The moral of the story is that something like this could possibly happen just about anywhere where anhydrous or propane is stored, although anhydrous is generally considered not to be an explosion risk. 

For the mother of all fertilizer explosion disasters,the Texas City disaster, go here.

Update: Apparently, there very likely was ammonium nitrate at the facility, and it was the cause of the explosion, not an anhydrous ammonia leak:
On Feb. 26, West Fertilizer, which is owned by Adair Grain, reported to the Texas Department of State Health Services that it was storing up to 270 tons of ammonium nitrate, plus up to 100,000 pounds of liquid ammonia, the Los Angeles Times reported. Officials said they did not yet know how much of the volatile chemicals were being stored when the facility, which blends and distributes fertilizer to local farmers, caught fire and exploded.
Ammonium nitrate, a key fertilizer component, can be explosive and has been used in roadside bombs in Afghanistan. Oklahoma City bomber Timothy McVeigh, an Army veteran, packed a rented truck with it.
"It is a very volatile material," says David Small, spokesman for the Pentagon's task force to counter improvised explosive devices, called IEDs. In Afghanistan, 80% of the roadside bombs that target U.S. and NATO troops are created from homemade explosives, and most of them are from ammonium nitrate, Small said.
Pentagon explosives experts told the Los Angeles Times that an explosion involving 270 tons of ammonium nitrate would be larger than almost any conventional U.S. weapon.
What I don't understand is why they were carrying ammonium nitrate.  I am guessing it is cheaper than urea or anhydrous ammonia, but if something happens, it can go boom, as we happened to see.  I talked to a local seed and chemical dealer at lunch today, and asked him about the explosion.  He didn't even think that ammonium nitrate was still available for retail sale. 

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