Productive naphtha type hydrocracking catalyst and application thereof

文档序号：893286 发布日期：2021-02-26 浏览：22次中文

阅读说明：本技术 一种多产石脑油型加氢裂化催化剂及其应用 (Productive naphtha type hydrocracking catalyst and application thereof ) 是由刘欣梅曾洪量张瑛梅刘振张占全孙发民阎子峰于 2019-08-20 设计创作，主要内容包括：本发明提供了一种多产石脑油型加氢裂化催化剂及其应用。该催化剂是由金属组分通过等体积浸渍法负载于酸性载体上制备得到的,其中,以重量百分比计,所述酸性载体的原料包括无机酸碱改性的Y型分子筛、大孔氧化铝和粘接剂,将上述原料混合成浆后挤条成型,干燥、烘焙得到所述酸性载体。本发明还提供了上述催化剂在多产石脑油型加氢裂化中的应用,其中,所述催化剂在进行加氢裂化反应前,通过预硫化使所述金属组分中的金属氧化物转化为金属硫化物。本发明提供的多产石脑油型加氢裂化催化剂具有明显的增产石脑油特征,其对石脑油的选择性最高为76.8％,对石脑油收率最高可达到61.5％。(The invention provides a high-yield naphtha hydrocracking catalyst and application thereof. The catalyst is prepared by loading metal components on an acidic carrier by an isometric impregnation method, wherein the raw materials of the acidic carrier comprise inorganic acid-base modified Y-type molecular sieve, macroporous alumina and a binder in percentage by weight, and the raw materials are mixed into slurry, extruded into strips, molded, dried and baked to obtain the acidic carrier. The invention also provides the application of the catalyst in the high-yield naphtha hydrocracking, wherein the catalyst is used for converting metal oxides in the metal components into metal sulfides through presulfurization before hydrocracking reaction. The high-yield naphtha hydrocracking catalyst provided by the invention has the obvious naphtha yield increasing characteristic, the highest selectivity to naphtha is 76.8%, and the highest yield to naphtha can reach 61.5%.)

1. A productive naphtha type hydrocracking catalyst is prepared by loading metal components on an acidic carrier by an isometric impregnation method;

the acidic carrier is prepared from the raw materials of, by weight, 20-40% of an inorganic acid-base modified Y-type molecular sieve, 50-70% of macroporous alumina and 5-10% of a binder, wherein the sum of the percentages of the components is 100%, the raw materials are uniformly mixed into slurry, extruded into strips, molded, dried and baked.

2. The catalyst of claim 1, wherein the metal component comprises tungsten and nickel, wherein the atomic ratio of W to Ni is 0.5:1 to 1.5: 1.

3. The catalyst of claim 1, wherein the inorganic acid-base modified Y-type molecular sieve is prepared by:

(1) mixing an industrial USY molecular sieve and an inorganic acid solution, and stirring to obtain a mixed solution;

(2) adding an inorganic alkali solution into the mixed solution obtained in the step (1), and stirring to obtain a mixture;

(3) and (3) washing, filtering and drying the mixture obtained in the step (2) by using deionized water to obtain the inorganic acid-base modified Y-type molecular sieve.

4. The catalyst according to claim 3, wherein the inorganic acid in step (1) comprises one of nitric acid, hydrochloric acid and hydrofluoric acid.

5. The catalyst of claim 3, wherein the inorganic base in step (2) comprises one of sodium hydroxide, potassium hydroxide and ammonia water.

6. The catalyst according to claim 3, wherein the concentration of the inorganic acid solution is 0.1-1 mol/L.

7. The catalyst according to claim 3, wherein the concentration of the inorganic base solution is 0.1 to 2 mol/L.

8. The catalyst of claim 3, wherein the solid-liquid mass ratio of the technical USY molecular sieve to the inorganic acid is 1:5 to 1:10, and the solid-liquid mass ratio of the technical USY molecular sieve to the inorganic base is 1:5 to 1: 10.

9. The catalyst according to claim 3, wherein the temperature of the stirring in step (1) is 80-100 ℃ and the temperature of the stirring in step (2) is the same as the temperature of the stirring in step (1).

10. The catalyst according to claim 3, wherein the stirring time in step (1) is 2 to 8 hours and the stirring time in step (2) is 0.5 to 4 hours.

11. Use of a catalyst according to any one of claims 1 to 10 in a high naphtha yield hydrocracking wherein the catalyst is used to convert metal oxides in the metal component to metal sulphides by presulfiding prior to carrying out the hydrocracking reaction.

Technical Field

The invention relates to the field of catalytic material synthesis and energy chemical industry, in particular to a productive naphtha hydrocracking catalyst and application thereof.

Background

With the obvious increase of the demand of our country market for high octane gasoline and ethylene products, the catalytic reforming and ethylene plant processing capacities are rapidly increased, resulting in the serious shortage of naphtha and ethylene cracking material. The development of the productive naphtha hydrocracking catalyst can relieve the current supply-demand contradiction, and has special advantages in the aspect of producing high-quality reforming raw materials (naphtha) and ethylene cracking raw materials (hydrogenation tail oil). The hydrocracking heavy naphtha has high aromatic potential and is a high-quality reforming feed, the tail oil has low BMCI value and can be used as a raw material for preparing ethylene by steam cracking, and simultaneously, the hydrocracking heavy naphtha can produce high-smoke-point high-quality No. 3 jet fuel and a clean diesel product meeting the European IV standard requirement.

The novel catalyst needs to improve the selectivity of the catalyst to naphtha fraction, reduce byproducts such as dry gas, liquefied gas and the like and reduce chemical hydrogen consumption on the basis of keeping the high activity of the existing catalyst. The hydrocracking catalyst is a bifunctional catalyst with hydrogenation and cracking activities, and the two functions must cooperate to jointly realize the high activity of the catalyst, the high selectivity of light oil, reasonable product distribution and the high cleanness of products. The optimization of the acidic component to the greatest extent possible is the key to optimizing the overall hydrocracking catalyst performance given the identity of the hydrogenation component. The Y-type molecular sieve is a commonly used acidic component, and in order to adapt to cracking reaction of heavy oil macromolecules, improve the yield of light oil and simultaneously reduce catalyst deactivation caused by carbon deposition, the molecular sieve is required to show acid strength gradient distribution, has moderate acid amount and uniform acid distribution, has a pore structure with the characteristic of micro-dielectric composite, and particularly has a developed secondary pore structure to meet the requirements of in-pore diffusion and reaction of the heavy oil macromolecules.

The Y-type molecular sieve has the advantages of strong acidity, good hydrothermal stability, high catalytic activity, economy, practicality and the like, and is a commonly used acidic carrier component for hydrocracking catalysts. The Y-type molecular sieve has an FAU-type framework structure, the aperture of the Y-type molecular sieve is concentrated at 0.74nm, and the size of heavy oil molecules is 1.5mm-15mm, so that the conventional Y-type molecular sieve is not beneficial to effective diffusion of heavy oil macromolecules in the molecular sieve, surface reaction and quick escape of reaction intermediate products, secondary cracking is aggravated, and the selectivity of target products is influenced. In order to meet the requirement of heavy oil macromolecule catalytic reaction, a proper mesopore needs to be introduced into a Y-type molecular sieve with a micropore structure, so that the limitation of the Y-type molecular sieve in the hydrocracking catalytic reaction due to the pore size is reduced. However, the acid density of the mesoporous-rich Y-type molecular sieve obtained by the conventional low-cost acid modification treatment method is sharply reduced, and the catalytic performance of the mesoporous-rich Y-type molecular sieve is influenced. The alkaline treatment process can better preserve the acid density in the molecular sieve due to the construction of secondary pores in the desilicated form, but is generally mainly applied to the treatment of molecular sieve types with higher silica-alumina ratio, such as ZSM-5 molecular sieves. The silica-alumina ratio of the Y-type molecular sieve is relatively low, when a single alkali treatment method is used for constructing mesopores, the treatment effect is not obvious in a low-concentration inorganic alkali solution, and excessive desilication can be caused by treatment of a high-concentration inorganic alkali solution, so that the crystallinity and the stability of the Y-type molecular sieve are obviously reduced. Therefore, when the Y-type molecular sieve is used as the acidic carrier component in the hydrocracking catalyst, how to construct the mesoporous structure on the premise of ensuring that the acid amount is suitable and the acid density distribution is uniform and the characteristic of micro-mesoporous composition becomes a key problem for preparing the productive naphtha hydrocracking catalyst.

Disclosure of Invention

In order to solve the above problems, an object of the present invention is to provide a high-yield naphtha hydrocracking catalyst and use thereof. The catalyst is prepared by loading metal components on an acidic carrier, wherein the acidic carrier is prepared by taking inorganic acid-base modified Y-type molecular sieve, macroporous alumina and a binder as raw materials. The obtained catalyst has the characteristic of producing naphtha in a high yield.

In order to achieve the aim, the invention provides a productive naphtha hydrocracking catalyst which is prepared by loading metal components on an acidic carrier by an isometric impregnation method;

In the above catalyst, preferably, the metal component comprises tungsten and nickel, wherein the atomic ratio of W to Ni is 0.5:1 to 1.5: 1.

In the above catalyst, preferably, the inorganic acid-base modified Y-type molecular sieve is prepared by the following steps:

(1) mixing an industrial USY molecular sieve and an inorganic acid solution, and stirring to obtain a mixed solution;

(2) adding an inorganic alkali solution into the mixed solution obtained in the step (1), and stirring to obtain a mixture;

(3) and (3) washing, filtering and drying the mixture obtained in the step (2) by using deionized water to obtain the inorganic acid-base modified Y-type molecular sieve.

In the above catalyst, preferably, the inorganic acid in step (1) includes one of nitric acid, hydrochloric acid and hydrofluoric acid.

In the above catalyst, preferably, the inorganic base in step (2) comprises one of sodium hydroxide, potassium hydroxide and ammonia water.

In the above catalyst, preferably, the concentration of the inorganic acid solution is 0.1 to 1 mol/L.

In the above catalyst, preferably, the concentration of the inorganic base solution is 0.1 to 2 mol/L.

In the above catalyst, preferably, the solid-liquid mass ratio of the industrial grade USY molecular sieve to the inorganic acid in step (1) is 1:5 to 1: 10.

In the catalyst, the solid-liquid mass ratio of the industrial grade USY molecular sieve to the inorganic base is preferably 1:5-1: 10.

In the above catalyst, preferably, the stirring temperature in the step (1) is 80 to 100 ℃, and more preferably, the stirring temperature in the step (2) is the same as the stirring temperature in the step (1).

In the above catalyst, preferably, the stirring time in the step (1) is 2 to 8 hours.

In the above catalyst, preferably, the stirring time in the step (2) is 0.5 to 4 hours.

The invention also provides the application of the catalyst in the high-yield naphtha hydrocracking, wherein the catalyst is used for converting metal oxides in the metal components into metal sulfides through presulfurization before hydrocracking reaction.

The method has the beneficial effects that the acid carrier is prepared by taking the inorganic acid-base modified Y-type molecular sieve, the macroporous alumina and the adhesive as raw materials, and the high-yield naphtha hydrocracking catalyst prepared by loading the conventional metal components has the obvious naphtha yield increasing characteristic, the selectivity of the catalyst to naphtha is up to 76.8 percent, and the yield of the catalyst to naphtha is up to 61.5 percent.

Detailed Description

The technical solutions of the present invention will be described in detail below in order to clearly understand the technical features, objects, and advantages of the present invention, but the present invention is not limited to the practical scope of the present invention.

Example 1

This example provides a productive naphtha hydrocracking catalyst, which is prepared by the following steps:

a solution of 0.1mol/L nitric acid (analytically pure, Sjogren chemical Co., Ltd.) and a solution of 0.3mol/L sodium hydroxide (analytically pure, Sjogren chemical Co., Ltd.) were prepared.

Adding USY molecular sieve (MNS-0 for industrial use, and pore structure data shown in column 1 of Table 1, from Shandong, Qilu, Xin, Ltd.) and prepared nitric acid solution into a three-neck flask according to a solid-liquid mass ratio of 1:5, and stirring in a constant-temperature water bath at 85 ℃ for 2 hours to obtain a mixed solution.

Adding the prepared sodium hydroxide solution into the mixed solution by using a dropping funnel according to the solid-liquid mass ratio of the USY molecular sieve to the sodium hydroxide solution of 1:5, and keeping the water bath temperature to continue stirring for 1 hour to obtain a mixture.

After the reaction is finished, washing the mixture for a plurality of times by deionized water, filtering, and drying in a drying oven at 110 ℃ to obtain the inorganic acid-base modified Y-type molecular sieve with the mesoporous specific surface area of 178m²The specific pore structure properties are shown in Table 1.

According to the weight percentage, 40% of inorganic acid-base modified Y-type molecular sieve, 50% of macroporous alumina and 10% of adhesive are taken as raw materials, a small amount of sesbania powder and dilute nitric acid which are taken as extrusion aids are added into the raw materials to be pulped, extruded into strips and formed, and the acidic carrier is obtained after drying and roasting.

Weighing a certain amount of ammonium metatungstate and nickel nitrate to be dissolved in deionized water according to the atomic ratio of W to Ni of 1:1, soaking the supported metal active component in an acidic carrier by adopting an isometric impregnation method, sealing overnight, drying at 120 ℃ for 4 hours, and then roasting at 510 ℃ for 4 hours to prepare the hydrocracking catalyst, which is recorded as Cat-1.

Example 2

This example provides a productive naphtha hydrocracking catalyst, which is prepared by the following steps:

a0.1 mol/L nitric acid (analytically pure, Sjogren chemical Co., Ltd.) solution and a 0.4mol/L potassium hydroxide (analytically pure, Sjogren chemical Co., Ltd.) solution were prepared.

Adding the USY molecular sieve and the prepared nitric acid solution into a three-neck flask according to the solid-liquid mass ratio of 1:5, and stirring for 2 hours in a constant-temperature water bath at 85 ℃ to obtain a mixed solution.

Adding the prepared potassium hydroxide solution into the mixed solution by using a dropping funnel according to the solid-liquid mass ratio of the USY molecular sieve to the potassium hydroxide solution of 1:5, and keeping the water bath temperature for continuously stirring for 1 hour to obtain a mixture.

After the reaction is finished, washing the mixture for a plurality of times by deionized water, filtering, and drying in a drying oven at 110 ℃ to obtain the inorganic acid-base modified Y-type molecular sieve with the mesoporous specific surface area of 169m²The specific pore structure properties are shown in Table 1.

Example 3

This example provides a productive naphtha hydrocracking catalyst, which is prepared by the following steps:

a0.2 mol/L hydrochloric acid (analytically pure, Sjogren chemical Co., Ltd.) solution and a 0.3mol/L sodium hydroxide (analytically pure, Sjogren chemical Co., Ltd.) solution were prepared.

Adding the USY molecular sieve and the prepared hydrochloric acid solution into a three-neck flask according to the solid-liquid mass ratio of 1:5, and stirring for 2 hours in a constant-temperature water bath at 85 ℃ to obtain a mixed solution.

Adding the prepared sodium hydroxide solution into the mixed solution by using a dropping funnel according to the solid-liquid mass ratio of the USY molecular sieve to the sodium hydroxide solution of 1:5, and keeping the water bath temperature for continuously stirring for 1 hour to obtain a mixture.

After the reaction is finished, washing the mixture for a plurality of times by deionized water, filtering, and drying in a drying oven at 110 ℃ to obtain the inorganic acid-base modified Y-type componentThe mesoporous specific surface area of the sub-sieve is 157m²The specific pore structure properties are shown in Table 1.

Example 4

This example provides a productive naphtha hydrocracking catalyst, which is prepared by the following steps:

a hydrofluoric acid (national chemical reagent, Inc., analytical pure) solution with a concentration of 0.1mol/L and a sodium hydroxide (analytical pure, Sjogren chemical Co., Ltd.) solution with a concentration of 0.4mol/L were prepared.

Adding the USY molecular sieve and the prepared hydrofluoric acid solution into a three-neck flask according to the solid-liquid mass ratio of 1:5, and stirring for 3 hours in a constant-temperature water bath at 85 ℃ to obtain a mixed solution.

Adding the prepared sodium hydroxide solution into the mixed solution by using a dropping funnel according to the solid-liquid mass ratio of the USY molecular sieve to the sodium hydroxide solution of 1:5, and keeping the water bath temperature for continuously stirring for 1 hour to obtain a mixture.

After the reaction is finished, washing the mixture for a plurality of times by deionized water, filtering, and drying in a drying oven at 110 ℃ to obtain the inorganic acid-base modified Y-type molecular sieve with the mesoporous specific surface area of 161m²The specific pore structure properties are shown in Table 1.

Example 5

This example provides a productive naphtha hydrocracking catalyst, which is prepared by the following steps:

a solution of nitric acid (analytically pure, manufactured by Sjogren chemical Co., Ltd.) and a solution of sodium hydroxide (analytically pure, manufactured by Sjogren chemical Co., Ltd.) were prepared at a concentration of pH 1 and 0.3 mol/L.

Adding the USY molecular sieve and the prepared nitric acid solution into a three-neck flask according to the solid-liquid mass ratio of 1:5, and stirring for 5 hours in a constant-temperature water bath at 85 ℃ to obtain a mixed solution.

Adding the prepared sodium hydroxide solution into the mixed solution by using a dropping funnel according to the solid-liquid mass ratio of the USY molecular sieve to the sodium hydroxide solution of 1:5, and keeping the water bath temperature for continuously stirring for 2 hours to obtain a mixture.

After the reaction is finished, washing the mixture for a plurality of times by deionized water, filtering, and drying in a drying oven at 110 ℃ to obtain the inorganic acid-base modified Y-type molecular sieve with the mesoporous specific surface area of 199m²The specific pore structure properties are shown in Table 1.

Example 6

This example provides a productive naphtha hydrocracking catalyst, which is prepared by the following steps:

Adding the prepared sodium hydroxide solution into the mixed solution by using a dropping funnel according to the solid-liquid mass ratio of the USY molecular sieve to the sodium hydroxide solution of 1:5, and keeping the water bath temperature for continuously stirring for 4 hours to obtain a mixture.

After the reaction is finished, washing the mixture for a plurality of times by deionized water, filtering, and drying in a drying oven at 110 ℃ to obtain the inorganic acid-base modified Y-type molecular sieve with the mesoporous specific surface area of 186m²The specific pore structure properties are shown in Table 1.

TABLE 1 Sieve pore Structure Properties of inorganic acid-base modified Y molecule before modification and in examples 1-6

Example 7

This example provides an activity evaluation of the productive naphtha hydrocracking catalyst prepared in the above example. A hydrocracking catalyst prepared by using an unmodified USY molecular sieve as a carrier is a comparative example and is marked as 'Cat-0'.

The hydrocracking reaction is carried out on a fixed bed micro-reaction device with the inner diameter of 10mm, and the specific process is as follows: 5mL of the catalyst was charged into the middle constant-temperature section of the reactor, and the upper and lower portions thereof were filled with quartz sand. Before the reaction, the reaction solution is added with 2 percent of mass fraction CS₂The catalyst is presulfurized to sulfide the metal oxide into a sulfided state. The pre-vulcanization comprises the following specific operations: introducing hydrogen into the reaction device at room temperature, heating to 170 ℃ at the speed of 3 ℃/min, then adding a vulcanizing agent, keeping the temperature constant at 230 ℃ for 1 hour, and vulcanizing at 320 ℃ for 4 hours to finish the vulcanization. In the prevulcanization process, the reaction pressure is 3MPa, and the liquid hourly space velocity is 2h^-1，V(H₂) V (vulcanizing agent) is 1000.

After the pre-vulcanization is finished, taking 98% of n-dodecane in percentage by mass as a simulated hydrocracking raw material, wherein the liquid hourly space velocity is 2h at 3MPa^-1，V(H₂) The hydrocracking reaction was carried out under the condition of V (n-dodecane) 800, and the reaction was carried out at a constant temperature of 320 ℃ for 5 hours, followed by sampling and analysis, and the naphtha yield of the hydrocracking catalyst was characterized by naphtha selectivity. The results of evaluation of the hydrocracking catalysts of examples 1 to 6 and comparative example are shown in table 2.

Table 2 results of hydrocracking reaction of each catalyst in example 7

Catalyst and process for preparing same	Conversion rate/%	Naphtha selectivity/%)	Yield/%
				Cat-0	81.9	65.3	53.5
Cat-1	74.5	76.8	57.2
				Cat-2	79.1	71.3	56.4
Cat-3	82.1	67.9	55.7
				Cat-4	85.9	66.3	57.0
Cat-5	87.4	70.4	61.5
				Cat-6	74.5	76.8	57.2

From the reaction results in table 2, it is understood that the naphtha yield of the hydrocracking catalyst prepared by using the modified Y molecular sieve of the example of the present invention as the carrier is greatly improved, wherein the catalyst Cat-5 prepared in example 5 has the highest naphtha yield.

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Productive naphtha type hydrocracking catalyst and application thereof

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