ABSTRACT
Butadiene is a basic raw material used in the manufacture of synthetic rubbers and an intermediate for the production of styrene copolymers. In the US, butanes–a component of natural gas liquids and liquified petroleum gas and butenes–are hydrogenated to butadiene on a large scale. Worldwide, 85% of butadiene is produced from C4 steam cracker fractions, a byproduct of ethylene manufacture, with the remainder from butane/butenes. Butadiene is isolated from other components by liquid extraction or extractive distillation. Butadiene is recovered from the top of the extraction tower and passes to a distillation column where the more volatile compounds are taken off at the top. A number of companies have developed one-or two-step catadiene dehydrogenation processes for the production of butadiene from mixed butane/butene streams. Some important outlets for butadiene, consuming 8% of global production, are acrylonitrile-butadiene-styrene and styrene-butadiene polymers. Butadiene is highly inflammable and forms explosive mixtures with air over a wide concentration.
