Verfahren zur Erhoehung des Siliciumdioxyd-Aluminiumoxyd-Molverhaeltnisses im Kristallgitter von kristallinen Alumosilicat-Zeolithen

1,186,934. Catalytic cracking. ESSO RESEARCH & ENG. CO. 11 May, 1967 [25 May, 1966], No. 21978/67. Heading C5E. [Also in Division C1] The activity and selectivity exhibited by crystalline aluminosilicate zeolite molecular sieves in the catalytic cracking of oil is improved by increasing the SiO 2 /Al 2 O 3 mole ratio in the crystal while maintaining or enhancing the degree of crystallinity. The process comprises (1) ion exchange of the zeolite e.g. faujasite to prepare the H+ or NH 4 +form (2) heat treatment of the zeolite in the critical presence of water at 1000‹ F for 16 hour; (3) steaming at 12000 F. for 16: hours; (4) leaching of the extraneous alumina from the product by treating with a. dilute mineral acid or an organic chelating agent e.g. ethylenediamine tetracetic acid selective for alumina. A faujasite treated as above. was compared with a standard catalyst of 5% regular H-faujasite in the same matrix and after. the same steam deactivation in a test for cracking oil. The higher activity shown by the treated catalyst is believed to be due to the better stability arising from the higher SiO 2 /Al 2 O 3 mole ratio of this catalyst. The improved selectivity of the treated catalyst is evidenced by the lower carbon make and higher yield of the gasoline fraction compared to that using the untreated catalyst.