Pyrophoric external

PYROPHORIC SUBSTANCE A material that undergoes such vigorous oxidation or hydrolysis (often with evolution of highly-flammable gases) when exposed to atmospheric oxygen or to water, that it rapidly ignites without an external source of ignition. This is a special case of spontaneous combustion. 

In the catalyst preparation area where the fire occurred, aluminum alkyl and isopentane are mixed in a batch blending operation in three 8000-gallon kettles. The flow rates of components are regulated by an operator at the control room. Temperature, pressure, and liquid level within the kettles are monitored by the control room operator. The formulated catalyst is stored in four 12,000-gallon vertical storage tanks within this process unit. Aluminum alkyl is a pyrophoric material and isopentane is extremely flammable. Each vessel was insulated and equipped with a relief valve sized for external fire. 

Immediately after the addition of trimethylaluminum is completed, external heating is begun and the crude product is distilled at 55-60° onto the sodium fluoride in flask D. The pure product is redistilled at about 56° from sodium fluoride into the receiving flask F. This flask is taken from the system, quickly fitted with an adapter equipped with a stopcock, and attached to a vacuum line for transfer into a storage vessel. ( Caution. Some flaming of the product may occur when the receiving flask is removed from the apparatus however, rapid and careful work should prevent any serious problems.) Extreme caution must be exercised in the disposal of the pyrophoric residues in flask B. 

External fire. May be prompted by flammable gas or vapor liquid, solid, metal, wood, or waste material pyrophoric material and presence of ignition source such as sparks, static, friction, hot spots, welding, lightning, auto ignition, or furnace. Immediate consequence engulfment, thermal radiation, fire damage, smoke, domino effect (where one incident is the primary cause for several other incidents). 

Carbon deposit Blocks catalyst pores Regenerate by burning carbon in a stream of air either in the reactor or externally if the catalyst is not pyrophoric. 

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