Optimized diesel hydrocracking catalyst and preparation method thereof

Abstract

The invention discloses an optimized diesel hydrocracking catalyst and a preparation method thereof. The raw materials include the following components and weight percentages: 1 to 25% modified molecular sieve, 10 to 65% γ-Al 2 O 3 , 15-70% amorphous silicon aluminum, 9-40% binder and 10-35% active metal oxide; the specific surface area of ​​the catalyst is 200-400m 2 / g, the total pore volume is 0.30~0.65cm 3 / g. The carrier of the present invention is used in preparing γ-Al 2 O 3 Modified molecular sieve is added to the inorganic aluminum salt solution, and after precipitation, drying and roasting, molecular sieve and γ-Al are obtained. 2 O 3 The composite material is then mixed, rolled, shaped, dried, and activated according to the material ratio of the catalyst, and the remaining materials are mixed with the composite material to obtain a catalyst. The molecular sieve in the catalyst carrier of the catalyst of the present invention has a high silicon-aluminum ratio, a large specific surface area, and is The high degree of dispersion in the carrier makes the carrier have more uniform acidic sites, and the alumina and molecular sieve are in closer contact, so that this catalyst can significantly reduce the freezing point of the diesel fraction and improve the performance of the diesel while ensuring a high yield of diesel. Cetane number.

Description

technical field [0001] The invention relates to a catalyst, in particular to an optimized diesel hydrocracking catalyst and a preparation method thereof. Background technique [0002] Hydrocracking is a very important technology for the efficient conversion of heavy oil and the production of clean oil products in the oil refining industry. It can process heavy crude oil with high sulfur and high metals. It has a wide source of raw materials, high production flexibility, good product quality and middle distillate Features such as high oil yield. Hydrocracking technology can directly produce low-aromatic, low-sulfur and low-nitrogen high-quality middle distillate products from vacuum diesel oil (VGO), which can meet increasingly stringent environmental protection requirements, and the catalyst plays a central role in the hydrocracking reaction. The key to hydrocracking technology lies in the development and improvement of catalysts. [0003] The conventional preparation meth...

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Problems solved by technology

[0004] However, in the hydrocracking catalyst prepared by the existing method, the components are simply mechanically mixed, and the components in the catalyst are easily agglomerated into secondary particles, which makes the dispersion of the active component poor, and the prepared catalyst is difficult to Play the best performance, but also have the problem of complicated preparation process and high cost

For example: CN98114489.6 discloses a hydrocracking catalyst, amorphous silica-alumina and Y-type molecular sieve are used as cracking components, and metal oxides of Group VIB and Group VIII are hydrogenation components, and a series of hydrocracking is adopted Production of middle distillate oil, the catalyst has good nitrogen resistance, but its preparation method is relatively complicated and the preparation cost is relatively high

CN139352IA discloses a medium-oil type hydrocracking catalyst and its preparation method. The carrier used in the catalyst is amorphous silica-alumina, alumina and composite molecular sieves of Y and β, wherein the composite molecular sieve is obtained by burning the former powder of β molecular sieve to remove the template agent. After mixing with modified Y molecular sieve, it is obtained by ammonium exchange treatment. The catalytic activity of this catalyst is not high, and the product quality of middle distillates of jet fuel and diesel oil is average, which needs to be further improved.

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