CN100406122C - A kind of preparation method of heavy, residual oil hydrogenation treatment catalyst - Google Patents

Abstract

The invention discloses a preparation method of a catalyst for hydrogenation treatment of heavy and residual oil. The impregnation method is used to load active metals and required additives on an alumina carrier to prepare the final catalyst. In the preparation process, the alumina carrier is made of crops Powders such as stem shells are pore-enlarging agents, and the addition amount is 10-20wt% of alumina. Compared with the prior art, the alumina carrier prepared by the method of the invention has the characteristics of large pore size, concentrated pore distribution, high mechanical strength, etc., and the method of the invention has a simple process, does not require special raw materials, and has low raw material costs and production costs. The heavy and residual oil hydrogenation treatment catalyst prepared by the method of the invention is suitable for various heavy and residual oil hydrogenation treatment processes.

Description

A kind of preparation method of heavy, residual oil hydrogenation treatment catalyst

technical field

The invention relates to a preparation method of a heavy oil and residual oil hydrogenation treatment catalyst, in particular to a preparation method of a heavy oil, residual oil hydrogenation demetallization and/or heavy oil hydrogenation desulfurization catalyst.

Background technique

Alumina carrier is a kind of commonly used catalyst carrier, which is widely used in petroleum processing, chemical industry, environmental protection and other fields. In some fields, alumina itself is a catalyst. The physical properties of alumina support, such as pore diameter, pore size distribution, mechanical strength, specific surface area, pore volume, etc., have a decisive influence on the properties of the catalyst containing it. In addition, in many industrial catalytic processing processes, the cost of the catalyst accounts for a relatively large proportion of the total cost. Therefore, reducing the raw material cost and processing cost of the catalyst is of great significance to the benefits of industrial production.

Hydrocarbon hydrotreating catalysts mainly use alumina carrier. In such catalysts, the active components are oxides of Group VIB metals and Group VIII metals. For heavy distillate oil, especially residue oil, most or even most of the metal elements in crude oil are concentrated, mainly Ni and V. These elements are usually present in the raw material in the form of metal-organic compounds together with elements such as sulfur, nitrogen and oxygen. During petroleum processing (such as residual oil hydrocracking, hydrodesulfurization, etc.), metal-organic compounds will decompose, and metal elements will be deposited on the inner and outer surfaces of the catalyst, and may even block the pores, resulting in a rapid decline in catalyst activity. . Therefore, in the hydrotreating of heavy oil and residual oil, it is necessary to use a demetallization catalyst in order to protect the catalyst from loss of activity due to a large amount of metal deposition.

Using a special demetallization catalyst is an effective way to solve the above problems. The main points of the method are: the demetallization catalyst is placed in front (above) of the hydrogenation (including hydrocracking, hydrodesulfurization) catalyst, so that the raw material oil is hydrogenated and removed from the raw material oil before entering the hydrogenation catalyst bed. Most of the metal impurities contained in it play a role in protecting the hydrotreating catalyst in the lower bed, so that it can maintain long-term stable hydrogenation activity.

Kobayashi et al. (Satoru Kobayashi et al.I&EC Research, 1987, 26: 2245-2250) proved that when the pore diameter of the residue hydrodemetallization catalyst was 10-15nm, the demetallization The ability to remove nickel and vanadium in raw oil is the strongest. Since the pore opening of the catalyst is continuously narrowed with the continuous deposition of metal impurities during the use of the catalyst, from the perspective of industrial application, the pore diameter should be larger, preferably 50% higher, reaching 15 ~20nm.

Therefore, as a heavy oil, residual oil hydrodemetallization and/or heavy oil hydrodesulfurization catalyst, two conditions are required: a large-pore carrier and a hydrogenation active component. The carrier generally adopts Al ₂ O ₃ or SiO ₂ -Al ₂ O ₃ with relatively large pore size, and the active metal component usually adopts VIB and VIII metal elements.

Alumina usually used to prepare hydrotreating catalysts and commercially available alumina have small pore diameters, which cannot meet the needs of preparing heavy oil, residue hydrodemetallization and/or heavy oil hydrodesulfurization catalysts. Therefore, the method of "hole expansion" must be adopted in the preparation process. One of the commonly used pore-enlarging methods is to add various pore-enlarging agents in the process of mixing, kneading, and extruding pseudo-thin hydrated alumina dry rubber powder.

US Patent (USP 4448896) and British Patent (EP 237240) use another class of substances: carbon black and carbon fibers as pore expanders. The pore-enlarging agent in the powder state is mixed with pseudo-thin hydrated alumina dry rubber powder, kneaded and extruded into strips. During the calcination process of the carrier, the pore expander is oxidized, burned, and finally converted into gas and escaped. In this way, a larger "cavity" is formed (leaved) in the carrier bulk phase, thereby generating large pores. alumina. However, the carrier and catalyst prepared by the above method have the following disadvantages: firstly, the pore distribution is dispersed and not concentrated. For example, the pore volume of the catalyst prepared by USP 4448896 with a pore diameter of 7.5-20nm accounts for 60% of the total pore volume. Second, the mechanical strength of the catalyst is too low for industrial use. David (UPS 4976848, 5089463) believes that the hydrodemetallization of residual oil requires not only large pores, but also a certain number of super large pores. It is not good if the number of such oversized holes is too much or too little. The balance among hydrodemetallization, hydrodesulfurization and de-CCR can be achieved only when the number of ultra-large pores is maintained at a certain number (for example, accounting for 5-11v% of the total pore volume). CN1256969A etc. propose to adopt two kinds of alumina with different forms, and use two kinds of pore-enlarging agents, physical pore-enlarging agent and chemical pore-enlarging agent, to obtain an alumina carrier with suitable performance, but the preparation process is complicated, and the raw material cost and production cost are relatively high. high.

Contents of the invention

Aiming at the deficiencies of the prior art, the present invention provides a method for preparing an Al ₂ O ₃ carrier with a large pore size, concentrated pore distribution, and good strength. The Al ₂ O ₃ carrier contains a part of super large pores, and the method of the present invention is simple in process. The raw material cost is low, and the final carrier cost is low. The alumina carrier of the invention can be used to prepare catalysts in the fields of petroleum processing, chemical industry, environmental protection and the like, and is especially suitable for preparing catalysts for hydrogenation of heavy and residual oils.

The preparation process of alumina carrier of the present invention comprises the following steps:

(1). Mix pseudo-boehmite dry rubber powder and pore-enlarging agent evenly, and knead it into a plastic body;

(2). Forming the plastic body obtained in (1), generally can be extruded by extruder;

(3). Drying and calcining the molded product obtained in (2) to obtain the final alumina carrier.

The pore-enlarging agent in step (1) is a high-molecular organic substance, such as crop stem shell powder, such as one or more of rice husk powder, peanut shell powder, coconut shell powder, and the like. Generally, the particle size of the powder is required to be >100 mesh, preferably >150 mesh. The amount of the pore-enlarging agent is equivalent to 10-25 wt % of the weight of the pseudo-alumina water, preferably 15-20 wt % of the weight of the pseudo-alumina water. Pseudo-boehmite can be a kind of pseudo-boehmite dry rubber powder or pseudo-boehmite dry rubber powder prepared by several different methods.

In step (1), it is also possible to add required auxiliary raw materials as required, such as adding materials containing silicon or boron, etc., to prepare alumina carriers containing corresponding auxiliary agents. It is preferred to add auxiliary silicon and silica sol, so that the final alumina carrier contains 1.0-3.0 wt% of SiO ₂ . In order to facilitate molding, appropriate amount of peptizing acid and extrusion aid can be added.

The drying process described in step (3) is generally dried at 100-120°C for 1-3 hours, or first dried at 60-70°C for 2-4 hours, then heated to 100-120°C, and dried for 1-3 hours . The roasting process is roasting at 750-950°C for 0.5-2 hours.

The pore-enlarging agent used in the present invention is an organic substance that is easy to decompose at a certain temperature, such as rice husk powder, peanut shell powder, coconut shell powder and the like. After these powdery granular substances are mixed with pseudo-boehmite dry rubber powder and silica sol, and kneaded into shape, when the molded product is roasted in the air, firstly, the granular organic matter contained in it will be uniformly decomposed and gradually "carbonized", resulting in Gaseous substances, the generation and escape of these gases will cause some large pores. Obviously, the "powdered particulate matter" here is essentially the "precursor" of "carbon". When the calcination temperature is higher, the "carbonized" substance reacts with the oxygen in the air and is further converted into gas, which further expands the pores of the alumina carrier. This "hole-making" and "hole-enlarging" process is "step-by-step and gradual", so it has little effect on the mechanical strength of alumina. During the kneading process, the addition of an appropriate amount of silica sol is beneficial to improve the thermal stability of alumina. The method of the invention is simple and does not need to add any new steps. The particle size of the pore-enlarging agent is easy to be uniform, and it is easy to mix with other materials evenly during the kneading process. Therefore, the pore distribution of the prepared alumina carrier is quite concentrated. In addition, the pore-enlarging agent used is a by-product or waste material in the process of agricultural product processing, has a wide range of sources, and is cheap, which can further reduce the cost of the catalyst.

Detailed ways

以重量计，载体含SiO₂ 1.0～3.0％。The alumina carrier prepared by the method of the present invention has a γ-Al ₂ O ₃ structure, a pore volume of 0.8 to 1.0 ml/g (mercury intrusion method), a specific surface area of 130 to 160 m ² /g (BET), and a most probable pore diameter of 15-20nm (mercury porosimetry). Pore volumes with pore diameters between 10 and 20nm account for more than 80% of the total pore volume, and pores >20nm account for 5% to 15% of the total pore volume, preferably 7 to 9%. The lateral compressive strength is above 10N/mm

By weight, the carrier contains 1.0-3.0% of SiO ₂ .

The Al ₂ O ₃ carrier of the present invention can be used in various catalysts, such as hydroprocessing catalysts, especially heavy and residual oil hydroprocessing catalysts.

When the alumina carrier of the present invention is used as a catalyst for hydrogenation of heavy and residual oil, the composition of the catalyst (calculated by catalyst weight) is: 3.0-8.0 wt% of NiO or CoO, preferably 4.0-7.0 wt%. The pore properties of the catalyst are similar to those of the carrier, the pore volume is 0.8-1.0ml/g (mercury intrusion method), the specific surface area is >130m ² /g (BET), and the most probable pore diameter is 15-20nm (mercury intrusion method). The pore volume with a pore diameter between 10 and 20 nm accounts for more than 80% of the total pore volume (mercury porosimetry). At the same time, it also contains a certain proportion (5-15v%) of super large pores. By weight, the carrier contains 1.0-3.0% of SiO ₂ . The mechanical strength (lateral pressure strength) of the catalyst is >10/mm (φ=0.8-2.0mm strip). The catalyst can be loaded with active metals and required additives by common impregnation method to prepare the final catalyst. Impregnation method Impregnation includes preparing the solution of the required active metal species and additives, impregnating the carrier with the solution, drying and roasting the carrier. Drying is usually done at 90-150°C for 2-5 hours, and firing is generally done at 400-600°C for 1-3 hours.

The above-mentioned hydrotreating catalyst needs to be presulfurized before use. The pre-sulfurization process can be carried out by feeding kerosene containing CS ₂ or other organic sulfur compounds in the presence of hydrogen. The catalyst of the present invention has good demetallization, desulfurization and de-CCR activities when treating heavy distillate oil, normal pressure and vacuum residue in the presence of medium-pressure hydrogen.

Example 1

(1). Vector preparation

Weigh 200g of pseudo-boehmite dry rubber powder, add 27g of rice husk powder (>130 mesh), 8g of silica sol (containing SiO ₂ 30wt%), 2g of extrusion aid Tianqing powder, 3% HNO ₃ 110ml and a small amount of H ₂ O. Mix well, knead into a plastic shape and extrude into strips (Φ=1.2mm). After air drying overnight, it was dried at 110°C for 3 hours.

The dried sample was placed in a high-temperature furnace, and the temperature was raised to 300°C at a rate of 100°C/hour, and then to 820°C at a rate of 80°C/hour, and then roasted at this temperature for 1.0 hour to obtain an Al ₂ O ₃ support.

(2). Dipping

Weigh 100g of Al ₂ O ₃ , add 150ml of Ni(NO ₃ ) ₂ solution (containing NiO 8.0g/100ml) and soak for 3 hours, and filter off the excess solution. The catalyst wet strips were air dried overnight.

(3). Catalyst drying and roasting

Put the dried sample of the catalyst (precursor) in a high-temperature furnace, raise the temperature to 120°C at a rate of 80°C/hour, dry for 2 hours, then raise the temperature to 520°C at a rate of 80°C/hour, and roast at a constant temperature for 2 hours to obtain Ni/ _{Al2O3 catalyst} .

Example 2

(1). Vector preparation

Same as Example 1 (1), but the pore-enlarging agent is changed into coconut shell powder (>170 mesh), and the addition is 30g.

(2). Dipping

Same as Example 1(2).

(3). Catalyst drying and roasting

Same as Example 1(3).

Example 3

(1). Vector preparation

Same as Example 1 (1), but the pore-enlarging agent was changed to peanut shell powder (>150 mesh), and the added amount was 38g, and the added amount of silica sol (containing SiO ₂ 30wt%) was changed to 11g.

(2). Dipping

Same as Example 1(2).

(3). Catalyst drying and roasting

Same as Example 1(3).

Example 4

(1). Vector preparation

With embodiment 1 (1). No silica sol was added, and the final firing temperature was 850°C.

(2). Dipping

With embodiment 1 (2).

(3). Catalyst drying and roasting

With embodiment 1 (3).

Example 5

(1). Vector preparation

With embodiment 1 (1). But the final firing temperature is 900°C.

(2). Dipping

Same as Example 1(2).

(3). Catalyst drying and roasting

Same as Example 1(3).

Comparative example 1

(1). Vector preparation

With embodiment 1 (1). But instead of rice husk powder, use carbon black, and the addition is 35g. The concentration of _HNO3 was changed to 2%, and the addition amount was 200ml.

(2). Dipping

Same as Example 1(2).

(3). Catalyst drying and roasting

Same as Example 1(3).

Comparative example 2

(1). Vector preparation

With embodiment 4 (1). But instead of starch, carbon black is used, and the addition amount is 35g. The concentration of _HNO3 was changed to 2%, and the addition amount was 200ml.

(2). Dipping

Same as Example 1(2).

(3). Catalyst drying and roasting

Same as Example 1(3).

The physical and chemical properties of the carriers and catalysts prepared in the above examples are listed in Table 1 and Table 2 respectively.

Table 1 Physicochemical properties of Al ₂ O ₃ prepared by different methods

Table 2 Physicochemical properties of each example catalyst

From Comparative Example 1 and Comparative Example 2 in Table 1, it can be seen that the carrier Al ₂ O ₃ prepared by using carbon black as a pore-expanding agent has a pore diameter less than 11nm, and the pores with a pore diameter between 10 and 20nm only account for 46-49% of the total pore volume, bulk density<0.48g/ml, mechanical strength (lateral pressure strength)<5.1N/mm. However, Examples 1-5, that is, the carrier Al ₂ O ₃ prepared by the new method, not only has a large pore diameter, but the pore diameter is more than 16mm, and the pore distribution is quite concentrated, and the pores with a pore diameter between 10-20nm account for the entire pore volume. 83-84% of the total pore volume, and some super-large pores (pores with a diameter greater than 20nm account for 7-15% of the total pore volume), and the mechanical strength is much larger, >13N/mm.

The activity evaluation test was carried out in a 200ml fixed bed hydrogenation unit. The raw material is 75wt% vacuum residue in sand mixed with 25wt% VGO in sand. The properties of raw materials are shown in Table 3. The reaction conditions are shown in Table 4. The evaluation results are shown in Table 5.

Table 3 Raw Oil Properties

Table 4 reaction conditions

The hydrogenation performance comparison of each example catalyst of table 5

It can be seen from the data in Table 5 that the catalyst of the present invention has higher activities of hydrodemetallization, hydrodesulfurization and de-CCR.

Claims (9)

1. the preparation method of a weight, catalyst for hydrotreatment of residual oil with infusion process supported active metal and required auxiliary agent on alumina support, prepares final catalyst, it is characterized in that the preparation method of described alumina support comprises:

(1). boehmite dry glue powder and expanding agent are mixed, and be kneaded into plastic;

(2). with (1) prepared plastic moulding;

(3). (2) prepared article shaped drying, roasting are made final alumina support;

Wherein the described expanding agent of step (1) is a crops stem shell powder, and addition is 10～25% of a boehmite dry glue powder weight.

2. in accordance with the method for claim 1, it is characterized in that described crops stem shell powder is one or more in powdered rice hulls, peanut hull meal, the coconut shell flour.

3. according to claim 1 or 2 described methods, it is characterized in that described crops stem shell particles of powder degree is＞100 orders, addition is 15～20% of a boehmite dry glue powder weight.

4. in accordance with the method for claim 1, it is characterized in that also adding the material that contains silicon or boron in step (1), preparation contains the alumina support of corresponding additive.

5. in accordance with the method for claim 4, it is characterized in that in step (1), adding Ludox, make in the final alumina support and contain SiO ₂1.0～3.0wt%.

6. in accordance with the method for claim 1, it is characterized in that the described dry run of step (3) for 100～120 ℃ dry 1～3 hour down, or, be warming up to 100～120 ℃ then, dry 1～3 hour at first 60～70 ℃ of oven dry 2～4 hours.

7. in accordance with the method for claim 1, it is characterized in that the described roasting process of step (3) is 750～950 ℃ of following roastings 0.5～2 hour.

8. in accordance with the method for claim 1, it is characterized in that described reactive metal is NiO or CoO, is that benchmark content is 3.0～8.0wt% with final catalyst.

9. in accordance with the method for claim 1, it is characterized in that described infusion process comprises solution preparation, dipping, dry and dry burning.