| 摘要 |
The catalytic cracking of petroleum hydrocarbons is effected in the presence of a crystalline zeolitic alumino-silicate having a pore size of 6-15 </>rA, containing an alkaline earth metal or zinc and having a silica to alumina mol. ratio of at least 3:1, e.g. 4-6:1. The catalyst is preferably a Y-type molecular sieve at least partly base-exchanged with an alkaline earth metal cation or zinc. Cracking of petroleum fractions boiling above 200 DEG C., e.g. in the range 300-600 DEG C., is effected using a fixed, moving or fluidized catalyst at 400-565 DEG C. and 1-8 atm. abs. and in fluid systems with a catalyst to oil ratio of 1-20:1. |
