Missed LA Bhopal: The 2015 Torrance, CA Exxon Refinery Explosion: A Nice Process Based Animation of the Failure.

[NNadir]

When I was a kid, in a bit of irony during my personal revolt against the internal combustion engine (which failed ultimately) I used to bicycle down Crenshaw Blvd in Torrance California on my way to work where there was a huge Exxon oil refinery which I knew had a huge amount, ton scale I believe, of hydrofluoric acid (HF), a cracking catalyst, that has terrifying properties.

(I once had to kick a bunch of guys working for me out of the lab and suit up in heavy PPE to clean up a spill they'd caused as a result of a deviation, of about 10 or 15 grams of liquid HF in a hood. It was the scariest incident in my career but no one was injured because remediation equipment was readily available in the lab.)

In 2017, there was a huge explosion at the refinery (which has since been sold by Exxon) leading to a 80,000 pound chunk of metal landing close to the HF tank. Had the tank ruptured it would have created a Bhopal like situation in Torrance and beyond. (See the second video below.)

There's a nice animation video of interest to chemical engineering types to explain what happened. Here it is:

A news item referring to the explosion:

There is no such thing as risk free energy technology, but some technologies are worse than others. I personally have no use for dangerous fossil fuels, because their use in normal situations is deadly, never mind their risks in abnormal situations.

I trust you're enjoying the weekend.

[4dog]

1. So what is the HF used for in refining, and where does it end up?

Reminded me that in HS chemistry I got to perform an "experiment," in which, following instructions, I mixed some F salt with H2SO4 in a dish, which was covered with a small glass plate that had been coated with paraffin wax, with a design scribed in it. No hood in the classroom, so I put the assembly outside the casement window and left it overnight. The glass plate was etched, as expected. I don't recall, but the residues probably went down the sink.

[4dog]

3. A quick search says that HF can be used in an alkylating unit

to make high-octane gasoline additives. Alternative to H2SO4. Also, poorer hits, to reduce S in diesel fuel.

[NNadir]

4. That was, I think, a potentially very dangerous experiment. Hopefully the "salt" was calcium fluoride.

This would have mitigated the danger, by making the release very slow.

The standard way to remediate small HF spills is to treat them with a calcium salt or better yet, calcium hydroxide. On skin, where it is very dangerous, since one will not know about the contamination until it is "too late" - a hole appears in the flesh - calcium gluconate is often used.

I doubt though that there was enough calcium hydroxide in all of Los Angeles County to neutralize the HF in that tank.

In the old days, I concede, some high school chemistry teachers used to do relatively dangerous things. To be perfectly honest, my interest in chemistry derives from my high school teacher tossing a piece of sodium metal in a glass beaker and blowing it to pieces.

I should state, to be perfectly honest, that I favor HF/salt eutectics as a means of reprocessing nuclear fuels. It would be, however, a very different ballgame.

[4dog]

5. One could add a list of dangers escaped, through grad school,

until I got to industry, which, at least in my corner, was much less careless.

[TalenaGor]

2. I used to work in a chevron and a shell oil refinery

early 90's in the SF bay area - the shell one had two explosions while I was there - the first was way far from where I was but the second one knocked me out of my chair and things fell off the walls and desks - scary af!