| 摘要 |
Provided is a phosphorus-containing ultrastable Y-type rare earth (RE) molecular sieve and the preparation method thereof. The method is: based on Na Y molecular sieve as a raw material, obtaining “one-exchange one-roast” RE-Na Y-type molecular sieve through the steps of exchanging with RE, pre-exchanging with dispersing, and the first calcination; and then performing ammonium salt exchange, phosphorus modification, and the second calcination on the “one-exchange one-roast” RE-Na Y-type molecular sieve, wherein the sequence of the RE exchange and the pre-exchange with dispersing is unlimited, and the sequence of the ammonium salt exchange and the phosphorus modification is unlimited as well. The obtained molecular sieve contains RE oxide 1-20 wt %, phosphorus 0.1-5 wt %, and sodium oxide no more than 1.2 wt %, and has a crystallization degree of 51-69% and a lattice parameter of 2.449-2.469 nm. Heavy oil conversion rate can be increased by using the molecular sieve as an active component in a catalytic cracking catalyst. |
| 主权项 |
1. A phosphorus-containing ultrastable rare earth Y-type molecular sieve, characterized in that the molecular sieve contains 1-20 wt % of rare earth oxide, 0.1-5 wt% of phosphorus in terms of P, and not more than 1.2 wt % of sodium oxide, and has a crystallinity of 51-69% and a lattice parameter of 2.449-2.469 nm; the preparation process of the molecular sieve includes rare earth exchange and dispersion pre-exchange, wherein a Na Y molecular sieve is used as a raw material, and wherein the rare earth exchange and the dispersion pre-exchange are carried out in an unlimited sequence, and are carried out continuously without a calcination process therebetween; the dispersion pre-exchange refers to adjusting the slurry of the molecular sieve to have a concentration, in terms of a solid content, of 80-400 g/L, and adding thereto 0.2 wt % to 7 wt % of a dispersant to conduct the dispersion pre-exchange at an exchange temperature of 0 to 100° C. for an exchange duration of 0.1 to 1.5 hours; in the dispersion pre-exchange, the dispersant is selected from any one or more of sesbania powder, boric acid, urea, ethanol, polyacrylamide, acetic acid, oxalic acid, adipic acid, formic acid, hydrochloric acid, nitric acid, citric acid, salicylic acid, tartaric acid, benzoic acid and starch; no ammonium salt is used in the rare earth exchange and the dispersion pre-exchange. |
