| 摘要 |
<p>CATALYST COMPOSITIONS Catalyst compositions comprising a crystalline aluminium silicate having a pore diameter larger than 0.7nm and at least an equal quantity by weight of a crystalline metal silicate having after one hour's calcination in air at 500.degree.C an X-ray powder diffraction pattern in which the strongest lines are the four lines mentioned in Table A and having in the formula which represents the composition of the silicate expressed in moles of the oxides and in which, in addition to SiO2, one or more oxides of an alkali metal (M) and one or more oxides of a trivalent metal X (Al, Fe, Ga, Rh, Cr and Sc) are present, the M2O/X2O3 molar ratio higher than 0.9 and the SiO2/X2O3 molar ratio higher than 10. The catalyst compositions are advantageously used in the production of gasoline by cracking hydrocarbon mixtures boiling above the gasoline range and allow a higher yield of cracked gasoline or a lower coke make.</p> |
