Alkylation in presence of thermally modified crystalline aluminosilicate catalyst

Claim 1

A process for effecting alkylation of an aromatic hydrocarbon charge which comprises contacting said aromatic hydrocarbon charge with an olefinic hydrocarbon alkylating agent under conditions effective for accomplishing said alkylation including a reactor inlet temperature between about 575° F. and about 900° F., a reactor pressure between atmospheric and about 3000 psig, employing a mole ratio of hydrocarbon aromatic charge to olefinic hydrocarbon alkylating agent in the approximate range of 1:1 to 30:1 and a total weight hourly space velocity between about 2 and 2000 in the presence of a catalyst comprising a crystalline aluminosilicate zeolite, having more than 50 percent of the cationic sites thereof occupied by hydrogen ions, said zeolite having a silica to alumina ratio of at least about 12, a constraint index within the approximate range of 1 to 12, said catalyst having been modified by prior thermal treatment at about 1200° F. to about 1800° F. in an inert atmosphere or at about 500° F. to about 1800° F. in steam to reduce the alpha value thereof to less than about 250.