Patent ID: 8742190

Claim:
A method comprising: introducing a benzene input stream containing at least 95 wt. % benzene to an alkylation reaction zone having an alkylation catalyst comprising a cerium promoted beta zeolite disposed therein in a plurality of catalyst beds; introducing an ethylene containing stream to each catalyst bed in the alkylation reaction zone, wherein at least a portion of the introduced ethylene containing stream is in the gaseous phase, wherein the ethylene containing stream is introduced in a manner to contact the benzene and the alkylation catalyst under alkylation conditions to produce a product containing alkylated benzenes and the catalyst becomes deactivated, and wherein the ethylene containing, stream further comprises methane, ethane, hydrogen, oxygen, CO2, or combination thereof; and recovering the product stream from the reaction zone, wherein the product stream comprises 0.8 wt. % or less butylbenzene; wherein the weight ratio of benzene:ethylene containing stream is from 3:1 to less than 28:1 per catalyst bed; regenerating the deactivated alkylation catalyst to produce a regenerated catalyst comprising: taking a reactor of the reaction zone offline; purging the alkylation catalyst disposed in the reactor with an inert gas at a purging temperature; heating the alkylation catalyst to a first temperature for a time period sufficient to provide an output stream having an oxygen content of about 0.5%; heating the alkylation catalyst to a second temperature higher than the first temperature for time period sufficient to provide an output stream having an oxygen content of about 2.0%; wherein the first and the second temperature are from about 50° C. to 200° C. above the purging temperature; and reusing the regenerated catalyst.