Hydrocracking method for producing low pour-point diesel

Abstract

The invention discloses a hydrocracking method for producing low pour-point diesel. The method comprises the following steps: enabling a wax-containing diesel raw material to be in contact with a hydrocracking catalyst to perform a hydrocracking reaction, and carrying out separation on an obtained hydrocracking product to obtain heavy naphtha and the low pour-point diesel, wherein the hydrocracking catalyst is prepared from a hydrogenation active metal component and carriers; the carriers comprise a modified Y-type molecular sieve, a beta molecular sieve and aluminium oxide; the modified Y-type molecular sieve has the following properties that: an average diameter of crystal particles is 2.0 to 5.0mu m, relative crystallinity is 110% to 150%, a SiO2 / Al2O3 molar ratio is 10 to 50, a unit-cell parameter is 2.436 to 2.450nm, and a pore volume occupied by pores with a pore diameter of 2nm to 6nm is 60% to 90% of a total pore volume. The method is particularly suitable for processing the high pour-point wax-containing diesel under the medium-pressure condition, and has very high catalytic activity and diesel selectivity; moreover, the reduction extent of a pour point of a diesel fraction is large, and product properties of the diesel are improved.

Description

Technical field [0001] The invention relates to a hydrocracking method, in particular to a hydrocracking method for maximum production of low-pour point diesel. Background technique [0002] The world's petroleum companies mainly use hydrodesulfurization catalysts, hydrodearomatization catalysts, and hydrogenation depressurization catalysts in the production of low-sulfur, low-aromatic, and low-pour-point clean diesel. They have developed a series of hydrogenation through various catalysts and process combinations. A series of process technologies for upgrading and reducing condensation. At present, the representative hydrogenation depressurization process technology is the MDDW single-stage hydrogen depressurization (catalytic dewaxing) process technology developed by Exxon Mobil, USA. The catalyst adopts ZSM-5 as the carrier matrix and carries a small amount of metal Ni component; The pour point depressing process technology developed by Global Solution Company uses SDD800 and...

AI Technical Summary

Problems solved by technology

This method uses expensive surfactants to prepare Y-type molecular sieves, and the preparation process is complicated, which greatly increases the preparation cost

[0009] CN97116250.6 discloses a kind of Y-type molecular sieve, the raw material that this Y-type molecular sieve adopts is common NaY former powder, first carries out ammonium exchange, removes NaY + , and then carried out two hydrothermal treatment and acid treatment, the distribution of pores larger than 2nm in the modified Y-type molecular sieve obtained was 40%~66% of the total pore volume, which affected the conversion of macromolecular aromatics in the raw material, and the prepared catalyst product Distribution and product quality need to be further improved

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