Holy Crap! Texas...

[Richtee]

Nitrates unleashed... wow... poor kid... hope she's allright...

 

http://www.youtube.com/watch?v=ROrpKx3aIjA&feature=player_embedded

 

Christ.

 

Hope everyone is well...

 

"The Mad Hunky" :{)

[BurritoBandito]

Yeah the explosion was really bad. I live in the Austin area and have family around Temple. My mother does HR for the Scott & White hospital there (in Temple). They are supposed to be bringing in close to 200 patients. In Austin they are holding a blood drive for the victims. The donation centers are packed. It was a huge shockwave which could be felt from around 40 miles away according to the news. It's really very sad.

 

Edit: it was actually anhydrous ammonia and not nitrates. However there was definitely ammonium nitrate present. They don't know what ignited the vapors or how the leak occurred. There was almost certainly chlorates present, I believe sodium chlorate is used as a weed killer. Sulfur is used to control mites and fungi. The disaster could have been due to chlorate contamination possibly. No one really knows for sure yet.

Edited April 18, 2013 by BurritoBandito

[eb11]

after that explosion dont think they will ever figure it out

[BurritoBandito]

You're probably right but I wouldn't be too surprised if they do.

[nater]

I think they will be able to piece together what happened.

 

There are conflicting reports whether is was Ammonia or Ammonium Nitrate. Some of what is being reported does not make sense and I would not be surprised if the journalists do not know the difference betweetn the two.

[BurritoBandito]

What could have caused the AN to detonate? My money is on the anhydrous. A leaky valve and small spark is all it would take. I guess we will find out eventually.

[nater]

There was a fire before the explosion, the heat from the fire could have caused the AN to detonate on its own.

 

Ammonia usually needs another catalyst to combust in the air. A source of chlorine would be extremy hazardous.

 

It will be interesting to hear what the investigators learn. It will take a while, but I am sure they will figure out a likely cause. Of course those of you nearby will probably hear better information than the rest of us.

Edited April 19, 2013 by nater

[NightHawkInLight]

Can ammonia detonate like that? It sure doesn't seem to me like enough gas could have achieved a fuel/air mix to cause an explosion on that scale without being touched off by the fire well before it reached that potential. There had to be a pile of nitrates involved.

[BurritoBandito]

It sure can. It's a big hazard for farmers because they use it for fertilizer then meth heads come up and steal it to go make drugs. Explosions have occured as a result of the meth heads manhandling the equipment and causing leaks, or trying to store it in a container that can't take the pressure. The crappy thing is that if the theif is hurt in the explosion the farmer is at fault and can be sued by the theif. It's called "strict liability" and is a bunch of bullshit IMO (See Greenman v. Yuba Power Products, 59 Cal.2d 57 (1963)).

 

Wikipedia:

Anhydrous ammonia is classified as toxic (T) and dangerous for the environment (N). The gas is flammable (autoignition temperature: 651 °°C) and can form explosive mixtures with air (16–25%). The permissible exposure limit (PEL) in the United States is 50 ppm (35 mg/m³), while the IDLH concentration is estimated at 300 ppm. Repeated exposure to ammonia lowers the sensitivity to the smell of the gas: normally the odour is detectable at concentrations of less than 50 ppm, but desensitised individuals may not detect it even at concentrations of 100 ppm. Anhydrous ammonia corrodes copper- and zinc-containing alloys, and so brass fittings should not be used for handling the gas. Liquid ammonia can also attack rubber and certain plastics.

Ammonia reacts violently with the halogens. Nitrogen triiodide, a primary high explosive, is formed when ammonia comes in contact with iodine. Ammonia causes the explosive polymerisation of ethylene oxide. It also forms explosive fulminating compounds with compounds of gold, silver, mercury, germanium or tellurium, and with stibine. Violent reactions have also been reported with acetaldehyde, hypochlorite solutions, potassium ferricyanide and peroxides.

Edited April 19, 2013 by BurritoBandito

[NightHawkInLight]

None of that states that ammonia can detonate on it's own, and the detonation of the explosives that can result from mishandling would be in far too small a quantity to account for the explosion in the video. They may be able to burst a tank and result in an explosion of the compressed gas escaping then igniting in the air, but to my eyes it's quite clear that it was a full detonation of a large amount of explosives, not a burst tank and secondary gas explosion.

[BurritoBandito]

The gas is flammable (autoignition temperature: 651 °°C) and can form explosive mixtures with air (16–25%). Granted, I dont have the expertise in explosives that you may, I am pretty sure that flamable gases can detonate. My research shows that deflagration to detonation transitions can and will occur quite easily when the gas is under partial confinement, like say, in a leaky tank. It isn't my intention to argue with you but if I am wrong I would like to know more about the subject.

[Mumbles]

What NHIL was saying is that Ammonia on it's own, without an oxidizer, cannot detonate. Ammonium nitrate can do this however. Certainly when mixed with the right amount of oxygen or oxidizer, ammonia is capable of an explosion.

[optimus]

Different angle:

 

http://www.youtube.com/watch?v=JTVUA-jJ11I&feature=player_embedded

 

That appears to be a firetruck in the foreground

Edited April 19, 2013 by optimus

[nater]

It isn't easy to get ammonia to detonate on its own, it needs a catalyst of some sort. By itself, it is non-flammable, but it becomes much more dangerous in the presence of an oxidizer. Ammonia is not good for you and will cause severe respiratory problems, but it isn't flammable unless there is an oxidizer. Read the MSDS sheets for it if you don't believe me. http://www.airgas.com/documents/pdf/001003.pdf

 

Any vessel that stores pressurized gas can experience a BLEVE (Boiling Liquid Expanding Vapor Explosion) This is when something that is stored as a liquid rapidly changes state to a gas. If the vessel is overfilled or is weakened, such as by fire, a BLEVE can occur. I'm not saying this happened in the case in Texas, just that it is a particular dangerous situation that can occur with gasses like this.

 

The biggest problem with the guys that use it to cook meth, were burns. It is very corrosive to the skin, muscous membranes and respiratory system. There was a guy in my parts who was badly burned while trying to pour it in a 5 gallon bucket after tapping into the proper vessel.

[flying fish]

With the amount of energy released, wouldn't there almost have to be an AN detonation involved? I mean, a fuel-air mixture confined only by the building could obviously destroy the building, but I wouldn't think it'd go so far as to register on a seismograph.

 

Also I thought I'd point out, this accident seems similar in nature to the PEPCON Ammonium Perchlorate disaster (except in the case of PEPCON there was a 4500 ton stockpile of AP due to the grounding of the space shuttle program - so the explosion was much larger)

[BurritoBandito]

Ok... Thank you guys for clearing that up. I see that the MSDS does in fact say that ammonia is non flammable. I'm going to show my ignorance here and just go ahead and ask; if it is non flammable then how does it have an autoignition temp.? I realize that it is a pretty high temperature but ignition is still a threat? I know that ammonia will not provide it's own oxygen to sustain combustion without an external oxidizer but isn't that true of hydrogen too? Hydrogen is considered to be explosive right? Aside from the obvious difference in flammability what's the difference? Again, I'm not trying to debate the explosive nature of ammonia, just trying to grasp the criteria for something to be considered flammable or explosive.

[flying fish]

This may be at least part of the answer to your question, from Wikipedia: "The combustion of ammonia in air is very difficult in the absence of a catalyst (such as platinum gauze), as the temperature of the flame is usually lower than the ignition temperature of the ammonia-air mixture. The flammable range of ammonia in air is 16–25%^"

 

http://en.wikipedia.org/wiki/Ammonia#Combustion

[BurritoBandito]

So basically the flame produced by burning ammonia is not hot enough to sustain the combustion?

[Mumbles]

You might have heard of this thing called the fire triangle? It says that you need a fuel, an oxidizer, and a heat/flame/spark source to make a fire. It might make more sense to think of it like that.

 

To initiate an explosion or fire, you need some sort of spark or heat input. Gasoline isn't flammable without an oxidizer around either, but that really isn't saying much. If you open a container of gasoline to the atmosphere, you bet it will form an explosive (flammable) mixture in the area above the can. If you were to put a match or spark to this, it would light on fire, and probably calmly burn for a while. If you were to enclose this in a confined box, it would probably explode when confronted with the same spark or flame. The auto-ignition temperature is the temperature at which the explosion or combustion will take place without the need for a spark or flame. The temperature alone provides enough energy to start the reaction. With many fuels, once the combustion reaction starts, it is self sustaining.

[dynomike1]

Here is one for you, i know this cause i work with anhydrous Before we send a tank to the field we put what is known as inserve in the anhydrous, what it is (supposed) to do is keep the anhydrous from leeching. It consist of Nitrus + Xylene. I have 250gal. of inserve sitting right behind our fertilizer plant.with a 30000 gal anhydrous tank between the plant and the inserve.

[Bobosan]

Yikes!

[BurritoBandito]

@mumbles...

Right, I understand that part. What I was kinda hazy on is as to why ammonia (in the presence of oxygen) is considered to be non flammable even though it can autoignite. I think that flying fish clarified that for me though. I just wanted to make sure that I understood correctly. Ammonia is considered non flammable because the temperature of the fire it produces once ignited is not sufficient to ignite itself? This is to say that it is capable of being burned, but not capable of sustaining the flame once the ignition source is removed? Am I understanding that correctly? BTW, doesn't AN decompose into nitrous oxide when heated at atmospheric pressure (asking, not stating)?

Edited April 19, 2013 by BurritoBandito

[Peret]

It was ammonium nitrate. (Reuters) "West Fertilizer Co is a retail facility that blends fertilizer and sells anhydrous ammonia and other chemical products to local farmers. It stored 270 tons of ammonium nitrate, according to a report filed by the company with the state government."

[dynomike1]

You have to have 1300+ deg. Fahrenheit and some other variables to make anhydrous burn. All tanks have pressure relief valves set at 150psi also flow restricted valves to regulate how fast it comes out. Did anyone frame the videos out? I noticed that it looked like the whole fertilizer house blew at the same time. The building has stalls in it probably 2 with Ammonia nitrate, 1 potash 1dap 1 ammonia sulfate, that being i don't know where dap and potash are flammable. So why did the whole house go up at the same time?

[Fireproofpyrotech]

Heard a story on the radio of a guy who has seen a little too much damage to our country the other day. The story goes that he and his wife were in Boston in the race when the explosion happened (they were fine) and later on the way home to Austin from a business trip in Dallas he saw the explosion in West... Just goes to show that anything can happen when you least expect it...Multiple times!