catalytic cracking

noun
1.
the reduction of the molecular weight of hydrocarbons by a catalyst, accomplished in a petroleum refinery by a type of chemical reactor (catalytic cracker)
Compare cracker (def 8), cracking (def 1).
British Dictionary definitions for catalytic cracker

catalytic cracker

noun
1.
a unit in an oil refinery in which mineral oils with high boiling points are converted to fuels with lower boiling points by a catalytic process Often shortened to cat cracker