| abstract |
1536828 Selective ethylation of monoalkyl benzenes MOBIL OIL CORP 4 July 1977 [19 July 1976] 27883/77 Heading C5E Toluene or ethylbenzene are selectively ethylated to produce p-dialkyl benzenes by contact with an ethylating agent (e.g. ethylene or ethyl alcohol) in the presence of a catalyst comprising a crystalline aluminosilicate zeolite, which zeolite is characterized by an activity, in terms of alpha value, between 2 and 5000, a xylene sorption capacity greater than 1 gram/100 grams of zeolite and an ortho xylene sorption time for 30% of said capacity of greater than 10 minutes, said sorption capacity and sorption time being measured at 120‹ C., and a xylene pressure of 4À5 Œ 0À8 mm. of mercury, said crystalline aluminosilicate zeolite having a silica to alumina ratio of at least 12 and a constraint index as herein defined within the range of 1 to 12. Suitable catalysts are obtained by modifying zeolites such as HÀZSMÀ5 with 0À5-40% by wt. of the oxides of P, Sb, B, U, Mg, Zn and/or Ca, or by steaming at 250- 1000‹ C. or by pre-coking to deposit 2-75 wt. per cent coke thereon. |