A Little Chemistry

I read Derek Lowe's In the Pipeline blog because from time to time it has something in it that I can enjoy despite my modest acquaintance with chemistry. Here's one that anybody can enjoy. A little post on a chemical reaction that goes BOOM! As Lowe points out, this company had "successfully" done this chemical reaction 175 times, but on the 176th it blew up...

I noted this item over at C&E News today, a report on a terrible chemical accident at T2 Laboratories in Florida back in 2007. I missed even hearing about this incident at the time, but it appears to have been one of the more violent explosions investigated by the federal Chemical Safety and Hazard Board (CSB). Debris ended up over a mile from the site, and killed four employees, including one of the co-owners, who was fifty feet away from the reactor at the time. (The other co-owner made it through the blast behind a shipping container and suffered a heart attack immediately afterwards, but survived).

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What's worth emphasizing is that this explosion occurred on the one hundred seventy-fifth time that T2 had run this reaction. No doubt they thought they had everything well under control - have any of you ever run the same reaction a hundred and seventy-five times in a row? But what they didn't know was crucial: the operators had only undergraduate degrees, and the CSB report concludes that the didn't realize that they were walking on the edge of disaster the whole time. As it turns out, the MCMT chemistry was mildly exothermic. But if the reaction got above the normal production temperature (177C), a very exothermic side reaction kicked in. Have I mentioned that the chemistry involved was a stirred molten-sodium reaction? Yep, methylcyclopentadiene dimer, cracking to monomer, metallating with the sodium and releasing hydrogen gas. This was run in diglyme, and if the temperature went up above 199C, the sodium would start reacting energetically with the solvent.

Experienced chemists and engineers will recognize that setup for what it is: a black-bordered invitation to disaster. Apparently the T2 chemists had experienced a few close calls in the past, without fully realizing the extent of the problem. On the morning of the explosion, the water cooling line experienced some sort of blockage, and there was (fatally) no backup cooling system in place. Ten minutes later, everything went up. In retrospect, the only thing to do when the cooling went out would have been to run for it and cover as much ground as possible in the ten minutes left, but that's not a decision that anyone usually makes.

Go look at the post. It has some pictures and lots more detail.

The funny thing is that as our society gets more technical and industrial it gets more dangerous in its capabilities. But at the same time, as we get more sophisticated we have actually become safer.

The doom-and-gloomsters would convince you that we need to give up all technology and go back to the horse-and-buggy days. But that isn't realistic given the 6+ billion population. And, those days were actually more violent than today!

I remember taking cross-country trips in a car when I was a kid and seeing the debris of car accidents littered on the highway. It was almost unheard of to make a thousand mile trip without seeing some head-on crash. But once the Interstate Highway System was in place and separated traffic into separate roadways, those head-on crashes mostly disappeared. Safety improved by at least 100-fold.

I don't understand the irrational fear of "the new" and "technology" by most people. The new inventions and new technology have made possible a much better life. But somehow that has been lost sight of. I fear it is like a lot of civilizations in history. The Romans rose to power on the backs of the small farmers who would endure hard labour. But when the big slave estates grew the army was filled by the urban proletariat and I believe (but have no facts) that the quality of the army went down. Pulling recruits from the bread-and-circuses crowd didn't give you the same grit and determination against the barbarians who knew a very tough life. So the edge of the Roman army was lost.

OK, maybe I'm subject to my own gloom-and-doom view when I consider the seeming inability of the US to pull up its socks and move into the future with assurance. Instead I see an ignorant crowd of religious fundamentalists and Green Party fraidy cats who want to ward off the future because they are terrified of it.