Method of hydrogenating cracking of hydrocarbons oily and method of preparation of a catalyst for the cracking of hydrocarbons oily hydrogenating

摘要

Hydrocarbon oils are cracked by contacting the oil in presence of hydrogen at elevated temperatures and pressures with a catalyst comprising fluorine preferably 0.1 to 5.0% by weight based on the catalyst and at least one metal of the iron group of the Periodic Table intimately associated with an acid acting support comprising at least one refractory oxide, the intimate association of the metal with the support having been achieved by contacting the support in hydrogel form with a solution of the said metals or metals, fluorine having been incorporated into the support while the support is in the hydrogel form. The support comprises silica and at least one of the following: alumina, magnesia, zirconia and boria. Preferably the supports comprises by weight 50% to 90% of silica and 50% to 10% alumina. The catalyst contains 0.1% to 14% by weight of the iron group metal e.g. nickel and cobalt. The catalysts may be prepared by contacting the hydrogel with a solution of the metal or metals the pH of the solution being 4 to 7. The hydrogel may be prepared by (1) mixing aqueous solutions of an alkali metal aluminate and an alkali metal silicate, adjusting the pH to 7 with mineral acid, aging and then washing the hydrogel to remove alkali metal ions; (2) adding mineral acid to an alkali metal silicate solution to adjust the pH to 2, adding an aluminium salt, adjusting the pH to 7 and washing the hydrogel formed. The hydrogel may be washed with ammonium nitrate solution to remove alkali metal ions. The fluorine is incorporated into the hydrogel by adding hydrofluoric acid or a water soluble fluoride, e.g. ammonium or sodium fluoride, to the aluminate solution used to prepare the hydrogel. The hydrogel is finally washed, dried and calcined at 427 DEG to 649 DEG C. The hydrogenation takes place at 260 DEG to 454 DEG C., 10.5 to 210 atmos. gauge, a L.H.S.V. of 0.2 to 10.0 litres of oil per hour per litre of catalyst and a hydrogen to oil mol. ratio of 5: 1 to 50: 1. The hydrocarbon feed boils above the gasoline boiling range e.g. 232 DEG to 510 DEG C. and may be pretreated by mild hydrogenation to remove coke forming constituents and to reduce the sulphur and nitrogen contents.