Q & A > Question Details
Cumene is known as isopropylbenzene, it is a flammable, colorless liquid that serves as a component to high octane fuels. Can any body tell me the best practices followed for storing?
In the hydrogenation section, if the isopropylbenzene had to be routed to storage what additional safeguards need to be required other than the coolers and N2 blanketed tank?
 
Answers
24/11/2009 A: keith bowers, B and B Consulting, kebowers47@gmail.com
Cumene has a rather low vapor pressure, similar to xylenes. Treat it just like a BTX stream and everything will be just fine.
Cumene was first manufactured in large quantities in WW II by alkylating benzene with propylene. It was an essential component of the highest octane aviation gasoline (115/145) because it has the highest known performance number ( amount of power possible without detonation or pre-ignition ). Unlike most aromatics, it has excellent response to anti-knocks (TEL,TML etc.)
The high octane gasoline was critical for the airlift into China over the 'hump'. The heavily loaded cargo planes with 4 high power turbo-compounded engines took off in very poor weather (the monsoon rains) and had to climb at maximum power for over 2 hours to get from sea-level to over the Himalyas. Lots of young pilots and crews died when engines failed from detonation and the plane could not climb steep enough to clear the rapidly rising terrain. With no visibility in continuous rain and solid clouds, rudimentary 'compass and watch dead reckoning' navigation , and very little margin for error, at best, it was a very high risk proposition.
Cumene boosted the anti-knock performance of the 'leaded up' av-gas significantly and helped, but was not, in itself, the answer. Combustion chamber deposits from lead antiknock levels over 5 gm/gal would start glowing as the engines got hotter and would cause pre-ignition, which would destroy the engine in seconds.
The YANKS invented tri-cresyl-phosphate (TCP) which, when added to the av-gas, effectively suppressed pre-ignition and significantly reduced engine failures and crew and plane losses. The losses from anti-aircraft and enemy fighter fire were so high the average life expectancy for these planes and engines was only 50 hours as it was, and 'flying the Hump' with all its engine failures lowered that short life substantially.