A process for the selective hydrogenation of alpha-methyl-styrene (AMS) to
cumene in a two catalyst system is disclosed. A crude cumene feed stream
containing up to 10% AMS by weight is supplied to the first reaction zone
112 and mixed with hydrogen in a first catalyst bed 118 containing a
nickel catalyst, converting from 70 to 95 percent of the AMS to cumene.
Cumene and remaining AMS are separated from hydrogen in a liquid take off
tray 120. The first reaction zone 112 effluent is supplied to a second
reaction zone 114, where the effluent and hydrogen gas are mixed in a
second catalyst bed 126 containing a noble-metal catalyst to
substantially convert any remaining AMS to cumene. Cumene is collected,
separated from the hydrogen, and can be resupplied to the hydrogenation
reactor 110, or supplied as feed to a phenol synthesis loop.