| 简介 |
FIELD : chemistry.
SUBSTANCE : invention relates to a method of preparing a catalyst for cracking petroleum hydrocarbons, particularly to a cracking catalyst which is a molecular sieve prepared using a gas-phase chemical method, and to a method of preparing the said catalyst. The catalyst for cracking petroleum hydrocarbons contains a Y-zeolite of a rare-earth form and a support which consists of a binder and clay, characterised by that content of rare-earth elements in the crystal lattice of the Y-zeolite having a rare-earth form is between 4 and 15 wt % RE2O3, the initial unit cell dimension is between 2.440 and 2.465 nm; the equilibrium unit cell dimension of the catalyst after holding in a medium of 100% steam at 800°C for 17 hours is greater than 2.435 nm, content of rare-earth elements in the support is equal to 1.0-8.0 % of the weight of the support. The method of preparing the said cracking catalyst involves the following steps : (1) ultra-stabilisation of Y-zeolite, involving : drying Y-zeolite until water content less than 10 wt %, addition into the atmosphere gaseous SiCl4 or gaseous SiCl4 carried by dry air at weight ratio of SiCl4 to Y-zeolite equal to 0.1-0.9 : 1, reaction of the said components at temperature of 100-600°C for 10 minutes to 6 hours and blowing Y-zeolite with dry air for 5 minutes to 2 hours; mixing the ultra-stabilised Y-zeolite directly with deionised water, suspension and possible grinding to a suspension of molecular sieve; (2) mixing the molecular sieve suspension with binder in form of a suspension and clay and suspension or suspension together with the binder and clay suspension successively and spray moulding and (3) washing the formed catalyst, filtration and drying.
EFFECT : obtaining a catalyst which is characterised by a stable structure, molecular sieve unit cell, high content of rare-earth elements, low content of sodium oxide and high temperature of differential thermal collapse, as well as high activity during cracking, high degree of conversion of heavy oil and high output of light oil; disclosed catalyst also considerably lowers content of olefins and is resistant to contamination with heavy metals.
20 cl, 25 ex, 19 tbl, 4 dwg |
客服热线：
手机版
二维码
