November 6, 2001, at 8 pm. I was completely alone in the lab due to the long procedure of my experiment. All other members left at 6 pm. The lab has three rooms, one big in the middle with two small rooms both sides, connected through inside doors. Suddenly I heard a kind of sound like popping of popcorn from the left side room. I did not pay too much attention. Around 15 minutes the sound was getting louder and forced me to pay attention. I went to the room but did not see any strange things. I came back to my fume hood and concentrated on my work. After some time I smelled of burning something. Immediately I stopped working at the point where I was, went to the small lab again to see whats going on. I saw a light of fire coming from a fume hood, the smell intense. Being absolutely alone in the lab I could not decide anything than escape. Immediately I took my coat and ran from the lab to outside and went down through the stairs. It was on the fifth floor of the building. Once I got out of the building I started to think, what should I do now. I was carrying my mobile phone but did not have any other's phone number. I saw outside a Chinese girl was coming from the library at the same time from the second floor and I told her about the fire and asked her to help me for calling someone. She said 'I won't tell you anything' and she left. I thought once should I just leave. But my mind did not let me leave and I stayed alone by looking at the top of the building. By then the fire might get bigger as I saw thick fumes are coming out from the chimney. My restlessness was increasing and instantly a Danish student came from somewhere on a bike. I stopped him, showed him the smoke coming from the roof of the building, and explained the incident. He immediately called the fire station with his phone. Within 10 minutes firefighters came and controlled the situation in an hour.
Hmmm.....what a saving!! when we knew that there were 6 drums of 5 liters hexane lying under the fume hood did not catch the fire while the whole upper part of the fume hood was burnt. If that hexane would catch the fire it can be imagined the worst situation.
The next morning, the cause was found out. The student who used that fume hood was doing catalytic hydrogenation using palladium charcoal during the day. After filtration of the catalyst, she threw the filter paper with the palladium charcoal in her waste container inside the hood. The normal practice of the lab allows us to simply gather the lab waste in a container inside the fume hood. She was perfectly alright.
Then what was wrong?
Some chemical compounds are pyrophoric in nature. That means they catch fire instantly when exposed to oxygen. Palladium/carbon become pyrophoric after absorbing hydrogen gas. So this catalyst should not be left dry after the use of hydrogenation reaction. Normally it should be deactivated by using 1N hydrochloric acid. The student did not deactivate the catalyst and when the solvents were evaporated under the strong suction of the fume hood, it dried up very soon and burnt. The popcorn popping sound at the beginning I heard was the burst of the catalyst before turning to the flame.
Hmmm.....what a saving!! when we knew that there were 6 drums of 5 liters hexane lying under the fume hood did not catch the fire while the whole upper part of the fume hood was burnt. If that hexane would catch the fire it can be imagined the worst situation.
The next morning, the cause was found out. The student who used that fume hood was doing catalytic hydrogenation using palladium charcoal during the day. After filtration of the catalyst, she threw the filter paper with the palladium charcoal in her waste container inside the hood. The normal practice of the lab allows us to simply gather the lab waste in a container inside the fume hood. She was perfectly alright.
Then what was wrong?
Some chemical compounds are pyrophoric in nature. That means they catch fire instantly when exposed to oxygen. Palladium/carbon become pyrophoric after absorbing hydrogen gas. So this catalyst should not be left dry after the use of hydrogenation reaction. Normally it should be deactivated by using 1N hydrochloric acid. The student did not deactivate the catalyst and when the solvents were evaporated under the strong suction of the fume hood, it dried up very soon and burnt. The popcorn popping sound at the beginning I heard was the burst of the catalyst before turning to the flame.
2 comments:
It must be really a memorable incident of your life ! To witness a fire ..that also in a new place with no one nearby...scary...you might have got hero's welcome next day as you were successful to stop expansion of the fire..
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