阅读说明：本技术 一种加氢处理催化剂的制备方法 (Preparation method of hydrotreating catalyst ) 是由 段为宇 王海涛 郭蓉 刘丽 姚运海 于 2019-04-19 设计创作，主要内容包括：本发明公开了一种加氢处理催化剂的制备方法,包括如下内容：(1)配制浸渍溶液,其中浸渍溶液为含有加氢活性金属、有机络合剂、烷基铵盐和/或磷酸酯盐和铝盐的水溶液；(2)取一定量的大孔氧化铝粉与步骤(1)的浸渍溶液,混捏、成型,干燥、焙烧后,得到氧化态加氢催化剂；(3)将氧化态催化剂进行硫化处理,得到加氢处理催化剂。本发明方法制备的催化剂具有更适宜的金属活性相、活性金属分散性好、堆积密度小等优点,适用于馏分油的加氢脱硫反应。(The invention discloses a preparation method of a hydrotreating catalyst, which comprises the following steps: (1) preparing an impregnation solution, wherein the impregnation solution is an aqueous solution containing hydrogenation active metal, an organic complexing agent, alkyl ammonium salt and/or phosphate ester salt and aluminum salt; (2) taking a certain amount of macroporous alumina powder and the dipping solution in the step (1), kneading, molding, drying and roasting to obtain an oxidation state hydrogenation catalyst; (3) and carrying out vulcanization treatment on the oxidation state catalyst to obtain the hydrotreating catalyst. The catalyst prepared by the method has the advantages of more suitable metal active phase, good active metal dispersibility, small bulk density and the like, and is suitable for the hydrodesulfurization reaction of distillate oil.)

1. A preparation method of a hydrotreating catalyst is characterized by comprising the following steps: (1) preparing an impregnation solution, wherein the impregnation solution is an aqueous solution containing hydrogenation active metal, an organic complexing agent, alkyl ammonium salt and/or phosphate ester salt and aluminum salt; (2) taking a certain amount of macroporous alumina powder and the dipping solution in the step (1), kneading, molding, drying and roasting to obtain an oxidation state hydrogenation catalyst; (3) and carrying out vulcanization treatment on the oxidation state catalyst to obtain the hydrotreating catalyst.

2. The method of claim 1, wherein: the concentration of the alkyl ammonium salt and/or the phosphate salt in the impregnation solution in the step (1) is 10 to 50 g/l, preferably 15 to 40 g/l.

3. The method of claim 1, wherein: the hydrogenation active metal comprises at least one VIB group metal and at least one VIII group metal which are hydrogenation active metals, and the VIB group hydrogenation active metal at least comprises Mo.

4. The method of claim 1, wherein: the organic complexing agent is one or more of organic acid, organic alcohol or saccharide; the addition amount of the organic complexing agent is 0.5-0.9 wt% based on the weight of C.

5. The organic acid is selected from one or more of dibasic acids with the carbon number of 2-10; the organic alcohol is selected from one or more of aliphatic alcohol with 3-10 carbon atoms and dihydric alcohol; the saccharide is selected from one or more of monosaccharide, disaccharide and polysaccharide with the carbon number of 3-10.

6. The method of claim 1, wherein: the alkyl ammonium salt is one or more of tetradecyl tributyl ammonium chloride, octadecyl trimethyl ammonium bromide, dodecyl trimethyl ammonium chloride, dodecyl dimethyl benzyl ammonium chloride or tetradecyl dimethyl benzyl ammonium chloride.

7. The method of claim 1, wherein: the phosphate salt is one or more of hexadecyl phosphate monoester, butyl octyl dithiophosphate or dodecyl phosphate monoester.

8. The method of claim 1, wherein: the aluminum salt is one or more of aluminum chloride, aluminum nitrate or aluminum sulfate.

9. The method of claim 1, wherein: the aluminum salt in the dipping solution is Al³⁺The molar ratio of the metal oxide to the hydrogenation active metal is 0.2-6.0, preferably 0.3-5.0, and the hydrogenation active metal is calculated by oxide.

10. The method of claim 1, wherein: the drying condition in the step (2) is that the temperature is 90-160 ℃, and the drying time is 1-24 hours; the roasting temperature is 400-750 ℃, and the roasting time is 2-10 hours.

11. The method of claim 1, wherein: and (3) adopting an in-situ or ex-situ vulcanization process for the vulcanization treatment, wherein the introduced vulcanizing agent accounts for 90-150% of the theoretical sulfur demand of the catalyst, and the vulcanization process adopts temperature programming, and the temperature is raised to 200-350 ℃ and is kept constant for 1-16 h.

12. A hydroprocessing catalyst prepared according to the method of claims 1-11, characterized by: based on the total weight of the catalyst, the catalyst comprises 14-50% of hydrogenation active metal, 49-85% of alumina and 0.5-1% of carbon, wherein the hydrogenation active metal is calculated by sulfide, and the carbon is calculated by element; wherein the hydrogenation active metal comprises at least one VIB group metal and at least one VIII group metal which are hydrogenation active metals, and the VIB group hydrogenation active metal at least comprises Mo; active phase MoS₂The average length of the platelets is 4-7 nm, the average number of the platelets in a single stack is 1-5, and the proportion of stacks with 3-5 layers is 40-90%, preferably 40-70%, based on the total number of stacks.

13. The hydroprocessing catalyst of claim 11, characterized in that: the weight ratio of the VIII group metal/(VIB group metal + VIII group metal) calculated by sulfide is 0.15-0.55.

14. The hydroprocessing catalyst of claim 11, characterized in that: the pore volume of the hydrotreating catalyst is 0.3-1.3 mL/g, and the specific surface area is 150-400 m²/g。

15. Use of the hydrotreating catalyst of claim 11 in a process for the hydrodesulfurization of liquefied gas, gasoline, kerosene, diesel oil, wax oil.

Technical Field

The invention relates to a preparation method of a hydrotreating catalyst, in particular to a preparation method of a hydrotreating catalyst for deep hydrodesulfurization of diesel oil.

Background

With the stricter environmental regulations, the requirements on the quality of diesel oil products are more and more strict, and especially the requirements on the content of sulfur in the diesel oil are more and more strict. In addition, with the increase of the processing amount of the sulfur-containing crude oil imported in China and the deterioration trend of the crude oil, the sulfur content and the aromatic hydrocarbon content of the diesel oil fraction are greatly increased, and the sulfur content and the cetane number become main restriction factors for upgrading the quality of diesel oil products in China. In order to accelerate the upgrading pace of diesel oil quality, various petroleum companies in the world develop different types of catalysts with advanced technologies successively by adopting different technologies in recent years, and the upgrading and upgrading of the catalyst activity are completed by preparing alumina modified carriers with proper pore volume, high specific surface area and acidity, which are suitable for macromolecular sulfide reaction, and improved measures such as a technology for ensuring good metal dispersion by gradient impregnation of active metals, an organic complex loading technology and the like.

CN 103769222 a discloses a distillate oil hydrotreating catalyst. The catalyst takes alumina as a carrier, at least one VIB group metal and at least one VIII group metal as hydrogenation active metals, the weight ratio of the VIII group metal/(VIB group metal + VIII group metal) calculated by oxides is 0.30-0.55, the catalyst contains an organic compound, the content of the organic compound in the catalyst is 1.0wt% -1.8 wt% by weight of C, and the organic compound is derived from organic acid and organic alcohol and/or organic sugar. A small amount of two organic compounds are added into the catalyst, and the hydrogenation activity of the catalyst is improved by adopting a higher ratio of VIII/(VIB + VIII).

CN 107774275A provides a preparation method of a hydrogenation catalyst. In the method, part of active metal components and organic acid complexing agents are introduced in the carrier forming process, the carrier is formed through a certain roasting treatment procedure, and then the subsequent active metal impregnation step is carried out to obtain the hydrogenation catalyst.

The hydrodesulfurization activity of the hydrodesulfurization catalyst is yet to be further improved to meet the increasingly stringent environmental emission requirements at present.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a preparation method of a hydrotreating catalyst. The catalyst prepared by the method has the advantages of more suitable metal active phase, good active metal dispersibility, small bulk density and the like, and is suitable for the hydrodesulfurization reaction of distillate oil.

The preparation method of the hydrotreating catalyst comprises the following steps: (1) preparing an impregnation solution, wherein the impregnation solution is an aqueous solution containing hydrogenation active metal, an organic complexing agent, alkyl ammonium salt and/or phosphate ester salt and aluminum salt; (2) taking a certain amount of macroporous alumina powder and the dipping solution in the step (1), kneading, molding, drying and roasting to obtain an oxidation state hydrogenation catalyst; (3) and carrying out vulcanization treatment on the oxidation state catalyst to obtain the hydrotreating catalyst.

In the method, the dipping solution in the step (1) contains 10 to 50 g/L of active metal dispersant, preferably 15 to 40 g/L.

In the method, the hydrogenation active metal comprises at least one VIB group metal and at least one VIII group metal which are hydrogenation active metals, and the VIB group hydrogenation active metal at least comprises Mo. The hydrogenation active metal source is a water-soluble compound containing hydrogenation active metal, and can be selected from soluble salts containing the hydrogenation active metal and the like commonly used in the field, and the adding amount is determined by the composition of the catalyst.

In the method, the organic complexing agent is one or more of organic acid, organic alcohol or saccharide; the addition amount of the organic complexing agent is 0.5-0.9 wt% based on the weight of C. The organic acid is selected from one or more of dibasic acids with the carbon number of 2-10, such as one or more of citric acid, citric anhydride, isocitric acid, malic acid, tartaric acid, oxalic acid, succinic acid, glutaric acid, adipic acid, benzoic acid, phthalic acid, isophthalic acid, salicylic acid or malonic acid; the organic alcohol is selected from one or more of fatty alcohol with 3-10 carbon atoms and dihydric alcohol, such as one or more of fatty alcohol, ethylene glycol, propylene glycol, glycerol, trimethylene ethane, trimethylene propane, diethylene glycol, dipropylene glycol, trimethylene glycol, triethylene glycol, tributylene glycol, tetraethylene glycol, tetrapropylene glycol, polyethylene glycol, diethylene ethylene glycol, diethylene allyl glycol or diethylene butyl glycol; the saccharide is selected from one or more of monosaccharide, disaccharide and polysaccharide with the carbon number of 3-10.

In the method, the alkyl ammonium salt is one or more of tetradecyl tributyl ammonium chloride, octadecyl trimethyl ammonium bromide, dodecyl trimethyl ammonium chloride, dodecyl dimethyl benzyl ammonium chloride or tetradecyl dimethyl benzyl ammonium chloride; the phosphate salt is one or more of hexadecyl phosphate monoester, butyl octyl dithiophosphate or dodecyl phosphate monoester.

In the method of the present invention, the aluminum salt is one or more of aluminum chloride, aluminum nitrate or aluminum sulfate.

In the method of the present invention, Al is used as the aluminum salt in the impregnation solution³⁺The molar ratio of the metal oxide to the hydrogenation active metal is 0.2-6.0, preferably 0.3-5.0, and the hydrogenation active metal is calculated by oxide.

In the method of the present invention, additives well known in the art, such as extrusion aid, peptizer, etc., are generally added during the kneading and molding processes in step (2). The extrusion aid is one or more of methyl cellulose, sesbania powder, starch and polyvinyl alcohol, and the addition amount of the extrusion aid is 1-5% of the total mass of the alumina powder; the peptizing agent is one or more of dilute nitric acid, dilute phosphoric acid and silicic acid, and the addition amount of the peptizing agent is 1-5% of the total mass of the alumina powder.

In the method, the drying condition in the step (2) is that the temperature is 90-160 ℃, and the drying time is 1-24 hours; the roasting temperature is 400-750 ℃, and the roasting time is 2-10 hours.

In the method, the vulcanizing treatment in the step (3) adopts an in-situ or ex-situ vulcanizing process, the amount of the introduced vulcanizing agent is 90-150% of the theoretical sulfur demand of the catalyst, and the vulcanizing process adopts temperature programming, wherein the temperature is raised to 200-350 ℃ and is kept for 1-16 hours.

In the method, the macroporous alumina powder can be prepared by a conventional method, the alumina powder can contain a small amount of one or more of silicon, titanium, magnesium, boron and zirconium, and the content of the auxiliary agent is 0.1-10% of the weight of the alumina powder calculated by elements. The properties of the alumina powder are generally required as follows: the pore volume is 0.3-1.5 mL/g, the specific surface area is 150-450 m²/g。

In the process of the invention, the concentration of the impregnation liquor is determined by the desired catalyst composition (content).

The hydrotreating catalyst prepared by the method comprises, by weight, 14-50% of hydrogenation active metal, 49-85% of alumina and 0.5-1% of carbon, wherein the hydrogenation active metal is calculated as sulfide, and the carbon is calculated as element; wherein the hydrogenation active metal comprises at least one VIB group metal and at least one VIII group metal which are hydrogenation active metals, and the VIB group hydrogenation active metal at least comprises Mo; wherein the weight ratio of the VIII group metal/(VIB group metal + VIII group metal) in terms of sulfide is 0.15-0.55; active phase MoS₂The average length of the platelets is 4-7 nm, the average number of the platelets in a single stack is 1-5, and the proportion of stacks with 3-5 layers is 40-90%, preferably 40-70%, based on the total number of stacks. The distillate oil hydrotreating catalyst has the pore volume of 0.3-1.3 mL/g and the specific surface area of 150-400 m²/g。

The hydrotreating catalyst prepared by the method is suitable for the hydrodesulfurization process of fractions such as liquefied gas, gasoline, kerosene, diesel oil, wax oil and the like, and is particularly suitable for the hydrodesulfurization process of diesel oil.

According to the invention, through the prepared impregnation solution, by utilizing the organic complexation of organic acid, organic alcohol and/or saccharide and hydrogenation metal, the effective control of alkyl ammonium salt and/or phosphate on the dispersion of active metal, the strong hydrolysis and acidity of aluminum salt in the process of dissolving the aluminum salt in water, and the synergistic effect of the components of the hydrogenation active metal, organic complexing agent, alkyl ammonium salt and/or phosphate and aluminum salt, the dispersion of the active metal is facilitated, the vulcanized catalyst forms active phase crystals with shorter length and fewer layers, more active centers which are easy to contact, such as edges, corners, edges and the like with higher activity are generated, and the hydrogenation activity of the catalyst is improved to a greater extent. The impregnating solution is introduced once in the carrier forming process, so that the viscosity of the impregnating solution, the extrusion assisting agent, the peptizing agent and water can be utilized to mix into a plastic body, the catalyst forming is more facilitated, and the operation is simple. Based on the preparation process, the catalyst has smaller bulk density, the bulk density is reduced by more than 10% compared with the existing catalyst, under the condition of the same device, taking the example of filling 300 tons of catalyst with the bulk density of 0.9g/mL, the catalyst only needs to be filled by 270 tons, the similar or better hydrodesulfurization effect is achieved, and the cost of a refinery is greatly reduced.

Drawings

FIG. 1 is a transmission electron micrograph of a catalyst of example 1 of the present invention.

FIG. 2 is a transmission electron micrograph of a comparative example 1 catalyst.

Detailed Description

In the present invention, the specific surface area and the pore volume are measured by a low-temperature liquid nitrogen adsorption method. The length of the lamella and the layer number ratio of the stacking layers are measured by a field emission transmission electron microscope: selecting more than 350 MoS₂Counting and arranging the average layer number, the average length and the proportion of 3-5 layers of wafers by using the platelets, wherein the statistical formula is as follows:

and

wherein l_iRepresenting the wafer length, N_iRepresents the number of i layers, a_iRepresentative wafer l_iNumber of (a), (b)_iNumber of representative layers N_iThe number of (2). In the present invention, wt% means mass percentage.

The present invention will be described in further detail with reference to examples. Wherein, the dry basis of 80 wt% refers to that the water content in the alumina dry glue powder is 20 wt%.