CN112973706B

CN112973706B - Nickel-based catalyst and preparation and application thereof

Info

Publication number: CN112973706B
Application number: CN201911288025.5A
Authority: CN
Inventors: 郑明远; 刘文飞; 于兆臣; 姜宇; 郭为磊; 赵宇; 张荣军; 张涛
Original assignee: Kairui Environmental Protection Technology Co ltd; Dalian Institute of Chemical Physics of CAS
Current assignee: Kairui Environmental Protection Technology Co ltd; Dalian Institute of Chemical Physics of CAS
Priority date: 2019-12-15
Filing date: 2019-12-15
Publication date: 2022-04-22
Anticipated expiration: 2039-12-15
Also published as: CN112973706A

Abstract

The invention provides a nickel-based catalyst and preparation and application thereof. The catalyst is prepared by taking nickel as a main active component and simultaneously containing an auxiliary agent component which comprises one or more than two of zirconium oxide, iron oxide and cobalt oxide, an auxiliary agent component which comprises one or more than two of titanium oxide, tin oxide, tungsten oxide, molybdenum oxide and magnesium oxide, and adopting an impregnation method, taking silica gel and alumina gel as binders, and obtaining the catalyst after impregnation, drying, roasting, forming and roasting. The catalyst has good activity in the hydrodesulfurization reaction of oil products.

Description

Nickel-based catalyst and preparation and application thereof

Technical Field

The invention relates to a nickel-based catalyst and preparation and application thereof. In particular to a catalyst which takes metallic nickel as a main active component and is prepared by an isometric impregnation method, and the catalyst is used for the hydrodesulfurization reaction of gasoline.

Background

In order to reduce the pollution of sulfur in gasoline and diesel oil to the atmosphere and the environment, strict regulations are set for the sulfur content of gasoline and diesel oil in various countries in the world. The traditional gasoline hydrodesulfurization process has large octane value loss while deep desulfurization, and a new process technology for producing the ultra-low sulfur gasoline is developed continuously abroad at present, wherein the CDHydro & CDHDS process developed by the American CD TECH company and the Prime G + process developed by the French Axens company have wide application prospects. The adopted process route is to catalyze diolefin in an oil product to perform a thioetherification reaction with mercaptan under mild critical conditions to generate larger-molecular thioether, simultaneously perform selective hydrogenation saturation on the diolefin in the gasoline, then divide the gasoline into a light component and a heavy component through a rectification process, wherein the light component is the blending component rich in olefin and having a higher octane number, and the heavy component is subjected to deep hydrodesulfurization, and the two processes can produce the gasoline with ultra-low sulfur and extremely little octane number loss.

At present, the research on the technology in foreign countries mainly focuses on the process aspect, and the reports on the catalyst used in the thioetherification reaction are less. Most of the catalysts adopt noble metal elements such as Pt and Pd with selective hydrogenation function, and the catalysts usually have stronger olefin saturation activity and higher cost. The nickel-based catalyst has relatively low price and moderate activity, and is attracted by researchers in recent years. In the aspect of thioetherification, Ni/Al2O3 catalysts [ petroleum refining and chemical, 2010,41,37-42 ] and Mo-Ni/Al2O3 catalysts [ petro-chemical, 2015,31,18-24 ] have been reported. However, the activity and selectivity of the catalyst are still unsatisfactory.

Disclosure of Invention

In order to achieve the above objects, the present invention provides a simple method of equivalent-volume impregnation, in which an auxiliary agent is impregnated on a nickel compound with a high specific surface area, thereby obtaining a higher catalytic activity, and simultaneously, an auxiliary active component is in close contact with nickel, thereby generating a synergistic effect, and obtaining optimal reaction selectivity and catalyst stability.

The technical scheme adopted by the invention is as follows:

the invention provides a nickel-based catalyst, which consists of an active component, an auxiliary agent I, an auxiliary agent II and a binder; the active component is nickel, and the content of nickel element in the catalyst is 50-80 wt%; the auxiliary agent I is one or more than two of zirconium oxide, iron oxide and cobalt oxide; the total content in the catalyst is 1-10 wt%; the auxiliary agent II is one or more than two of titanium oxide, tin oxide, tungsten oxide, molybdenum oxide and magnesium oxide, and the total content of the auxiliary agent II in the catalyst is 1-10 wt%; the catalyst is prepared by taking an insoluble nickel compound as a carrier, impregnating an auxiliary agent I and an auxiliary agent II, drying, roasting (preferably air), adding a binder, molding and roasting; the insoluble nickel compound is nickel oxalate, nickel carbonate, basic nickel carbonate, nickel hydroxide, nickel oxide or nickel protoxide.

The specific surface area of the nickel oxalate, the nickel carbonate, the basic nickel carbonate, the nickel hydroxide, the nickel oxide and the nickel protoxide is higher than 20m²/g。

In another aspect, the present invention provides a method for preparing the above nickel-based catalyst, comprising the steps of:

(1) preparation of the catalyst precursor: dissolving one or more soluble salts in the first auxiliary agent and one or more soluble salts in the second auxiliary agent in water to prepare a mixed solution, adding an insoluble nickel compound into the mixed solution, uniformly stirring the mixed solution, standing the mixed solution for 6 to 24 hours, drying the mixed solution at a temperature of between 80 and 150 ℃, and roasting the dried mixed solution for 0.5 to 4 hours at a temperature of between 250 and 550 ℃ to obtain a catalyst precursor;

(2) and (3) catalyst molding: adding a binder into the catalyst precursor, uniformly stirring, preparing molded particles by adopting an extrusion molding or rolling molding method, drying at 80-150 ℃, and roasting at 250-650 ℃ for 0.5-4h to obtain the nickel-based catalyst;

(3) the nickel-based catalyst needs to be reduced for 0.5-5h at the temperature of 150-500 ℃ in a hydrogen atmosphere before use.

The insoluble nickel compound is nickel oxalate, nickel carbonate, basic nickel carbonate, nickel hydroxide, nickel oxide or nickel protoxide; the soluble salt of the first auxiliary agent is chloride, thionyl chloride, nitrate, nitrite, phosphate, sulfate, sulfite and zirconium oxychloride of zirconium, iron and cobalt; the soluble salt of the second auxiliary agent is chloride, thionyl chloride, nitrate, nitrite, phosphate, sulfate, sulfite, tungstate, metatungstate and molybdate of titanium, tin, tungsten, molybdenum and magnesium;

the adhesive is formed by mixing alumina gel and silica gel, the total content of the adhesive in the catalyst is 5-30 wt% calculated by alumina and silica, and the mass ratio of the silica to the alumina in the adhesive is 0.1-10; the silica gel contains 10-50 wt% of silica, and the aluminum gel contains 5-20 wt% of aluminum oxide.

The formed particles are spherical, granular, tooth-shaped, annular, flaky and strip-shaped catalyst particles with the diameter, length and thickness of 1-10 mm.

The invention further provides an application of the nickel-based catalyst, and the catalyst can be applied to hydrodesulfurization reaction of oil products, and particularly can be used for mercaptan catalytic thioetherification reaction in gasoline.

The catalytic reaction is carried out in a fixed bed reactor, the reaction temperature is 80-150 ℃, the hydrogen pressure is 0.1-2MPa, the hydrogen-oil volume ratio is 100-10000, and the reaction space velocity is 0.1-10h^-1。

The nickel-based catalyst prepared by the invention can be applied to the hydrodesulfurization reaction of oil products, is not limited to a fixed bed reactor, and can also be applied to a reaction rectification reaction system to realize desulfurization and product refining.

The catalyst is prepared by taking nickel as a main active component and simultaneously containing an auxiliary agent component which comprises one or more than two of zirconium oxide, iron oxide and cobalt oxide, an auxiliary agent component which comprises one or more than two of titanium oxide, tin oxide, tungsten oxide, molybdenum oxide and magnesium oxide, and by adopting an impregnation method, silica gel and aluminum gel are taken as binders, and the catalyst is obtained by impregnation, drying, roasting, molding and roasting. The catalyst has good activity in the hydrodesulfurization reaction of oil products, and needs to be reduced before use. Has the following advantages:

(1) the synthesis method is simple, the active components are in a high dispersion state with a nano scale, the nickel catalyst has high activity, and can catalyze mercaptan in an oil product to generate thioetherification reaction under a mild condition to generate larger-molecular thioether, so that the gasoline hydrodesulfurization is realized.

(2) The cocatalyst in the catalyst can avoid the deactivation of the nickel nano particles due to sintering in the reduction and use processes, and improve the stability of the catalyst.

(3) The catalyst uses multi-metal to modify the nickel component, has synergistic effect, and improves the reaction selectivity of the catalyst.

The present invention will be described in detail with reference to specific examples, which are not intended to limit the scope of the present invention.

Example 1

Preparation of catalyst 1: adding 3g of zirconium oxychloride (aid I) and 3g of stannous chloride (aid II) into 80ml of water, stirring for dissolving, and adding the mixture with the specific surface area of 50m²100 g/g nickel oxalate, stirring uniformly, standing for 12h, drying at 120 ℃ overnight, and roasting at 450 ℃ for 2h to obtain the precursor.

Taking 20g of the precursor, adding 5g of silica gel containing 40 wt% of silicon dioxide and 10g of alumina gel containing 13 wt% of alumina, fully kneading, extruding the sample into a strip with the diameter of 2mm, drying at 120 ℃ overnight, roasting at 450 ℃ for 2h to obtain the nickel-based catalyst 1, and reducing at 400 ℃ for 3h in a hydrogen atmosphere before use.

Example 2

Preparation of catalyst 2: adding 3g of ferric nitrate and 3g of ammonium metatungstate into 80ml of water, stirring and dissolving, and adding the mixture with the specific surface area of 50m²100 g/g nickel oxalate, stirring uniformly, standing for 12h, drying at 120 ℃ overnight, and roasting at 450 ℃ for 2h to obtain the precursor.

Taking 20g of the precursor, adding 5g of silica gel containing 40 wt% of silicon dioxide and 10g of alumina gel containing 13 wt% of alumina, fully kneading, extruding the sample into a strip with the diameter of 2mm, drying at 120 ℃ overnight, roasting at 450 ℃ for 2h to obtain the nickel-based catalyst 2, and reducing at 400 ℃ for 3h in a hydrogen atmosphere before use.

Example 3

Preparation of catalyst 3: 3g of ferric nitrate and 3g of ammonium molybdate are added into 80ml of water, stirred and dissolved, and added with the specific surface area of 50m²In terms of/gAnd (3) 100g of nickel oxalate is uniformly stirred and then is kept stand for 12h, dried at 120 ℃ overnight and roasted at 450 ℃ for 2h to obtain a precursor.

Taking 20g of the precursor, adding 5g of silica gel containing 40 wt% of silicon dioxide and 10g of alumina gel containing 13 wt% of alumina, fully kneading, extruding the sample into a strip with the diameter of 2mm, drying at 120 ℃ overnight, roasting at 450 ℃ for 2h to obtain the nickel-based catalyst 3, and reducing at 400 ℃ for 3h in a hydrogen atmosphere before use.

Comparative example 1

Catalyst 4 preparation (addition of adjuvant I only, no adjuvant II): the procedure is as in example 1, except that stannous chloride is not added to obtain catalyst 4.

Comparative example 2

Catalyst 5 preparation (addition of adjuvant II only, no adjuvant I): the procedure is as in example 1, except that zirconium oxychloride is not added, to obtain catalyst 5.

Comparative example 3

Preparation of catalyst 6: the preparation of catalyst 6 was carried out in the same manner as in example 1 except that the specific surface area of the carrier of nickel compound was 10m²Per g of nickel oxalate, catalyst 6 is obtained.

Comparative example 4

Preparation of catalyst 7: the alumina supported catalyst is prepared through mixing nickel nitrate, ferric nitrate and ammonium metatungstate in solution and soaking in Al₂O₃The catalyst 7 is obtained by drying the carrier with the loading of nickel of 40 wt%, the loading of iron of 2 wt% and the loading of tungsten of 2 wt% at 120 ℃ overnight and roasting at 500 ℃ for 2h, and is reduced in hydrogen at 400 ℃ for 3h before use.

Comparative example 5

Preparation of catalyst 8: the procedure is as in example 1, except that no auxiliary I or II is added, to obtain catalyst 8.

Evaluation of reaction Performance of catalysts obtained in example 1 and comparative example

A fixed bed hydrogenation reaction device is adopted, and the performance of the catalyst is evaluated by taking the gasoline containing the thiol as a raw material. The reactor was charged with 1g of catalyst, and the catalyst performance was evaluated at 120 ℃ under conditions of 1.0MPa hydrogen, 3ml/h raw material flow, and 60ml/min hydrogen flow. The reaction was sampled every 2 hours. Catalyst activity is expressed in mercaptan conversion. The results of the reaction evaluation of the respective catalysts are shown in Table 1.

TABLE 1 evaluation of catalyst reactivity

In Table 1, the conversion of mercaptan in nickel-based catalyst 1, nickel-based catalyst 2, and nickel-based catalyst 3, prepared in examples 1-3, was maintained at around 90% over 14 hours without significant degradation.

Comparative example 3 catalyst 6 prepared from a support with a smaller specific surface area and catalyst 7 prepared according to comparative example 4 (conventional process) both had a lower mercaptan conversion of less than 50%. When the specific surface area of the carrier nickel compound is 10m²At the time of/g, the catalytic performance of the obtained catalyst 6 is obviously reduced, which shows that the specific surface area of the nickel compound has great influence on the activity of the catalyst.

The catalyst 8 prepared in comparative example 5, to which the aid I and the aid II were not added, had not high initial activity and was deactivated rapidly.

Compared with the catalyst 4 and the catalyst 5 which are not simultaneously added with the auxiliary agent I and the auxiliary agent II, the nickel-based catalyst 1, the nickel-based catalyst 2 and the nickel-based catalyst 3 which simultaneously contain the auxiliary agent I and the auxiliary agent II have higher activity and better stability, and the combined action of the auxiliary agent I and the auxiliary agent II can effectively improve the catalytic activity and the stability. Catalyst 4 has higher initial activity but poor stability, and the catalyst deactivates faster, and catalyst 5 deactivates slower, but the overall activity is not high, and the mercaptan conversion rate is lower than that of nickel-based catalyst 1, nickel-based catalyst 2, and nickel-based catalyst 3.

In addition, compared with the conventional impregnation method for preparing the catalyst 7, the catalyst prepared by the technical scheme of the invention has the advantages of obviously improved activity and better stability, and the catalyst prepared by the synthesis method of the invention has more excellent performance.

From the above reaction results, it can be seen that the nickel-based catalyst 1, the nickel-based catalyst 2, and the nickel-based catalyst 3 of the present invention have good reaction performance in the thioetherification reaction, and the conversion rate of the thiol is high and stable.

Test example

Testing the specific surface area of the catalyst by adopting a physical adsorption method; the particle size of the catalyst was measured by XRD (X-ray diffraction) and calculated by scherrer's formula.

Table 2 characterization comparison of catalyst performance

As can be seen from the data in the table, the nickel-based catalyst 1, the nickel-based catalyst 2, the nickel-based catalyst 3 and the catalyst 8 obtained by the catalyst preparation method provided by the application have nickel particles in a nano-scale dispersed state before use; after the catalyst is used for 14 hours, the specific surface areas of the nickel-based catalyst 1, the nickel-based catalyst 2 and the nickel-based catalyst 3 and the particle sizes of the nickel nanoparticles are not obviously changed, the specific surface area of the catalyst 8 is obviously reduced, and the particle size of the nickel is obviously increased, which shows that the addition of the auxiliary agent I and the auxiliary agent II can effectively stabilize the nickel nanoparticles.

Application example 2 comparison of the Performance of catalysts prepared by using different nickel compounds as carriers

Respectively with specific surface area higher than 20m²The catalyst was prepared using nickel carbonate, basic nickel carbonate, nickel hydroxide, nickel oxide, and nickel protoxide as carriers in the same manner as in example 1, the obtained catalyst was labeled as catalysts 9 to 13, the catalyst performance evaluation manner was the same as in the application example, and the reaction evaluation results of the catalysts are shown in table 3.

TABLE 3 evaluation results of various supported catalysts

From the above reaction results, it can be seen that the catalysts prepared by using different nickel compounds as carriers all have better reaction performance in the thioetherification reaction, wherein the catalyst prepared by using nickel oxalate as a carrier has the best catalytic performance.

Claims

1. A preparation method of a nickel-based catalyst is characterized by comprising the following steps:

the catalyst consists of an active component, an auxiliary agent I, an auxiliary agent II and a binder;

the active component is nickel, and the content of nickel element in the catalyst is 50-80 wt%;

the auxiliary agent I is one or more than two of zirconium oxide, iron oxide and cobalt oxide; the total content in the catalyst is 1-10 wt%;

the auxiliary agent II is one or more than two of titanium oxide, tin oxide, tungsten oxide, molybdenum oxide and magnesium oxide, and the total content of the auxiliary agent II in the catalyst is 1-10 wt%;

the catalyst is obtained by taking an insoluble nickel compound as a carrier, impregnating an auxiliary agent I and an auxiliary agent II, drying, roasting, adding a binder, molding and roasting;

the insoluble nickel compound is nickel oxalate, nickel carbonate, basic nickel carbonate, nickel hydroxide, nickel oxide or nickel protoxide;

the insoluble nickel compound has a specific surface area of more than 20m²/g；

The preparation method of the nickel-based catalyst comprises the following steps:

(1) preparation of the catalyst precursor: dissolving one or more soluble salts in the auxiliary agent I and one or more soluble salts in the auxiliary agent II in water to prepare a mixed solution, adding an insoluble nickel compound into the mixed solution, uniformly stirring, standing for 6-24h, drying at 80-150 ℃, and roasting at 250-550 ℃ for 0.5-4h to obtain a catalyst precursor;

2. The method of claim 1, wherein:

the soluble salt of the auxiliary agent I is soluble salt of zirconium, iron or cobalt;

the soluble salt of the auxiliary agent II is soluble salt of titanium, tin, tungsten, molybdenum and magnesium.

3. The method of claim 1, wherein:

the soluble salts of zirconium, iron and cobalt are chloride, chlorite, nitrate, nitrite, phosphate, sulfate, sulfite and zirconium oxychloride;

the soluble salts of titanium, tin, tungsten, molybdenum and magnesium are chloride, nitrate, phosphate, sulfate, tungstate, metatungstate and molybdate of titanium, tin, tungsten, molybdenum and magnesium.

4. The method of claim 1, wherein: the formed particles are spherical, granular, tooth-shaped, annular, flaky and strip-shaped catalyst particles with the diameter, length and thickness of 1-10 mm.

5. The method of claim 1, wherein:

the adhesive is formed by mixing alumina gel and silica gel, the total content of the adhesive in the catalyst is 5-30 wt% calculated by alumina and silica, and the mass ratio of the silica to the alumina in the adhesive is 0.1-10;

the silica gel contains 10-50 wt% of silica, and the aluminum gel contains 5-20 wt% of aluminum oxide.

6. Use of the nickel-based catalyst prepared by the preparation method according to any one of claims 1 to 5 in hydrodesulfurization reactions of oils.

7. Use according to claim 6, characterized in that: the reaction is a mercaptan catalyzed thioetherification reaction in gasoline.

8. Use according to claim 6, characterized in that: the catalytic reaction is carried out in a fixed bed reactor, the reaction temperature is 80-150 ℃, the hydrogen pressure is 0.1-2MPa, the hydrogen-oil volume ratio is 100-10000, and the reaction space velocity is 0.1-10h^-1。