I'm not sure if I've told this story before - perhaps on my previous blog. The memory is with me so vividly that the retellings run together.
I've never liked hydrogenation rooms. For my non-lab audience, that's where we keep the equipment for running reactions in pressure vessels under hydrogen gas, always with some sort of metal catalyst to make the hydrogen come in and reduce things. It's about as close to witchcraft as modern organic chemistry gets.
And it's just those ingredients that make me nervous. Big metal cylinders of hydrogen gas can't help but bring to mind visions of the Hindenberg, for one thing. If something fails on the apparatus, it generally fails with spraying, fizzing, and/or flames. And any hydrog room that's been around a few years invariably picks up black residues of spilled catalyst everywhere. It's in the cracks of the lab bench and in the fittings of the equipment.
You want to be careful with that stuff. Most of the time, we use powdered charcoal impregnated with palladium or platinum, which looks like, well, charcoal. But under the right (um, wrong) conditions, it can come to life like you wouldn't believe. In the presence of hydrogen gas and some air, such as when you mess up and open the flask, the powder gets so hot it glows bright orange. It looks like it's just come out of a furnace, and that's about when it ignites your reaction solvent. Then you might as well get out the hot dogs and suntan lotion, because the fireworks are going off already.
Once about thirteen years ago, I was in my company's old hydrogenation room getting a balloon full of the gas to take back to my lab. You can run less vigorous reactions under just that much gas, so there's generally some fitting for people to fill things up to go. In this case, you opened up the valve near the gas cylinder just a crack, and then opened up the needle valve near the balloon a lot.
Or, anyway, that's how we'd been doing it. When I got there that afternoon, someone had just decided that they liked it better the other way around, where you just barely dinked the balloon takeoff valve. News to me. I stuck my balloon assembly on, opened the valves up the way I was used to, and KA-BLAM!
Off goes my whole balloon and tubing rig, flying off the fitting from the blast of gas. And up I went, straight into the air, with my hair, I swear, standing straight out from my head in some sort of mad-scientist perm. My adrenal glands hit the Emergency Squirt button and dumped their entire load of adrenaline into my bloodstream, convinced that at long last a sabretooth had shown up at the mouth of the cave.
I landed on my toes and bounced back up like a rubber ball. A videotape of my actions would be worth watching; I've often been sorry that I don't have one. I was pinging around the room kicking at the cabinets, waving my arms and gibbering obscenities. It took a couple of circuits of the place before I could slow down enough to be sure that I had all my extremities attached. I hate hydrogenation rooms. . .
1. comgelo on April 26, 2004 5:31 AM writes...
Best regards from Portugal:-)
Permalink to Comment2. Chris Hoess on April 26, 2004 2:35 PM writes...
Something similar happened in my first undergraduate lab with a small hydrogenation bomb. Apparently the rupture disc started leaking and so the graduate student replaced it with a spare...which turned out to be rated to a significantly lower PSI. I wasn't there to witness it--I was tending a reaction in the other lab upstairs at the time--but according to the undergraduate who was there, both he and the grad student hit the deck and bounced simultaneously when the rupture disk blew as they were bringing it up to operating pressure.
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