WO2020103919A1

WO2020103919A1 - Multi-metal unsupported hydrorefining catalyst, preparation method therefor and application thereof

Info

Publication number: WO2020103919A1
Application number: PCT/CN2019/120127
Authority: WO
Inventors: 李�灿; 刘铁峰; 刘欣毅
Original assignee: 中国科学院大连化学物理研究所
Priority date: 2018-11-25
Filing date: 2019-11-22
Publication date: 2020-05-28
Also published as: CN111215094A; CN111215094B

Abstract

The present invention relates to a multi-metal unsupported hydrorefining catalyst, and a preparation method therefor. The hydrorefining catalyst consists of at least one +three-valent metal oxide, at least one Group VIII metal oxide, at least one Group IVB metal oxide, and at least two group VIB metal oxides. The catalyst contains 10-50 wt.% of Group VIII metal, 1-30 wt.% of Group IVB metal, 1-50 wt.% of +three-valent metal, and 5-80 wt.% of two Group VIB metal by the metal oxide. Also disclosed is an application of the catalyst in the ultra-deep hydrodesulfurization and denitrification of a diesel fraction process: at the temperature of 280-440ºC, the hydrogen pressure of 1-20 MPa, the volume ratio of hydrogen to the diesel fraction of 50-1,000 V/V, and the volumetric air speed of the diesel fraction of 0.1-10h-1, the catalyst can remove sulfur and nitrogen in a model diesel to below 10 ppm.

Description

Multi-metal unsupported hydrorefining catalyst, preparation method and application thereof

Technical field

The invention belongs to the field of petrochemical industry, and particularly relates to a multi-metal unsupported hydrorefining catalyst and its preparation method, and its application in the process of ultra-deep hydrodesulfurization and denitrification of diesel fractions.

Background technique

Since the SOx produced by burning sulfur compounds in fuel oil is the main culprit of air pollution and acid rain, and it will also cause irreversible poisoning of the three-way catalyst of the exhaust purification system of automobile engines, environmental laws and regulations around the world restrict fuel sulfur content The requirements are becoming stricter. At present, all countries in the world have promulgated and implemented strict fuel sulphur content standards: The European V standard implemented on September 1, 2009 stipulates that the sulfur content in diesel is less than 10mg / kg, and the national V standard issued by China also stipulates diesel sulfur content Below 10mg / kg, it was first implemented in Beijing on February 1, 2013, and implemented nationwide on January 1, 2018. In addition, nitrogen-containing compounds can lead to poisoning of the sulfide catalyst used in the hydrodesulfurization process and the molecular sieve catalyst used in the catalytic cracking process, resulting in a decrease in performance. Considering the current decline in world oil reserves and the problems of heavy and inferior oil, the development of ultra-deep hydrodesulfurization and denitrification catalysts with higher performance has attracted more and more attention in the petrochemical industry.

The sulfur-containing compounds in diesel are mainly mercaptans, thioethers, thiophene and its derivatives, benzothiophene and its derivatives, dibenzothiophene and its derivatives, of which 4,6-DMDBT is the most difficult to remove by hydrogenation Of sulfur compounds. Nitrogen-containing compounds are mainly amines, pyrrole and its derivatives, pyridine and its derivatives, quinoline and its derivatives, indole and its derivatives, carbazole and its derivatives, etc., of which quinoline compounds are basic A class of nitrogen-containing compounds that are difficult to remove by hydrogenation. At present, the most widely used diesel desulfurization and denitrification technologies in the industry are hydrodesulfurization and hydrodenitrogenation processes. The catalysts used are mainly alumina-supported transition metal catalysts, including Co-Mo-S / Al2O3, Ni-Mo -S / Al2O3, Ni-WS / Al2O3, Ni-Co-Mo / Al2O3 and Ni-Co-Mo-W / Al2O3 etc. With the tightening of the standards for sulfur content defined by environmental regulations and the increase in sulfur and nitrogen content caused by the heavy and inferior crude oil, the use of existing catalysts and process conditions or the use of new reactors to achieve ultra-deep desulfurization and desulfurization Nitrogen faces huge operating costs and investment costs. In contrast, it is a more economical and feasible method to develop a new hydrorefining catalyst that can perform ultra-deep desulfurization and denitrification on existing production facilities and in accordance with current operating conditions.

For the traditional alumina-supported hydrorefining catalyst, on the one hand, since the catalytic effect is improved only by increasing the dispersion of the active components and promoting the synergy between the active components, the catalytic effect of the carrier itself is limited, and the carrier and the active component The strong interaction between them makes it difficult for some active components to be activated and utilized, so the improvement of traditional supported hydrorefining catalysts is greatly restricted. For the unsupported hydrorefining catalyst, due to avoiding the strong interaction between the carrier and the active component, and having the characteristics of the type of active component and the number of active centers, it is reflected in the hydrorefining process of diesel The ultra-high desulfurization and denitrification activities have high research value and application prospects.

Related literature and patents reported early on the bulk catalyst with the metal component NiMoW and its ultra-high hydrodesulfurization catalytic activity, and caused widespread concern. US patents US6783663, US6712955, US6758963, etc. reported the synthesis and application of new NiMoW bulk catalysts, whose hydrodesulfurization activity is about three times that of other industrial reference catalysts. The catalyst synthesis method disclosed in the above patent includes the following steps: 1) First, a complex reaction is performed with ammonia water and a nickel salt solution and molybdate and tungstate are added to form a solution; 2) Heating causes the nickel ammonia complex to decompose nickel ions Reacts with molybdate and tungstate to produce NiMoW catalyst precursor; 3) Produces NiMoW sulfide catalyst by roasting and vulcanization. Because the concentrated ammonia water used in the synthesis process will pollute the environment, the nickel-ammonia complex is not easy to decompose due to its stability, resulting in nickel-ammonium complex ions remaining in the final mother liquor, causing pollution and waste. The specific surface area and pore volume of the prepared catalyst are relatively high Small (less than 120m2 / g and 0.2ml / g, respectively), which is not conducive to the diffusion of reactants in the catalyst during the hydrogenation reaction. For the hydrodesulfurization reaction of diesel, excellent catalysis can be exhibited under high pressure above 6MPa The activity makes the catalyst have higher requirements on the reaction device, which limits its application in industry.

G. Alonso Nunez et al. Reported the use of different raw materials and vulcanization in Catalysis Letters 99 (2005) 65-71, Applied Catalysis A: General 302 (2006) 177-184, Applied Catalysis A: General 304 (2006) 124-130 To prepare synthetic NiMoW bulk catalyst, the catalyst has a special scale shape and a high surface area, but the disadvantage is that the preparation process is complicated, and the raw materials used are expensive, and the production process is cumbersome, resulting in increased production cost of the catalyst, which is difficult to achieve industrialization.

Chinese patent CN1339985A discloses a method for synthesizing NiMoW catalyst: in aqueous solution, soluble molybdenum and tungsten salts react with basic nickel carbonate, and then sulfide it to obtain a catalyst. Since the basic nickel carbonate used in this patent is insoluble in water, and its synthesis reaction is a displacement reaction between ions and solids, it is difficult to obtain a catalyst with a small grain size, which limits the degree of dispersion of its active components.

Chinese patents CN100569920C, CN100590179C, CN100590180C, CN101089134B, CN101280216B, CN101280220B disclose NiMoW hydrogenation phase catalysts, the synthesis method is: first, the nickel salt is mixed with the tungstate to produce nickel-tungsten composite oxide NixWyOz, then mixed with MoO3 After the reaction, the catalyst is finally filtered, shaped and activated. Since the catalyst in this patent reacts through two insoluble particles of nickel-tungsten composite oxides NixWyOz and MoO3 in the state of slurry, there is a limit to the degree of reaction, so that the active metal component in the final catalyst cannot be completely dispersed evenly.

Chinese patents CN102451707B, CN102773108B, CN103055887B, CN106179383B, CN106179388A, CN106179390A disclose NiAlMoW hydrogenation phase catalysts. The introduction of Al improves the specific surface area and pore volume of the catalyst, but due to the interaction between Al and active metals, its hydrogenation catalysis The activity is limited, and the catalyst is still reacted by two insoluble particles containing aluminum-nickel-tungsten composite oxide and MoO3 in the state of slurry. The reaction degree is limited, resulting in the active metal component in the final catalyst still cannot be completely dispersed Evenly.

Chinese patents CN106622299A, CN107051467A, CN106824215A, CN106944100A, CN106944089A, CN106902836A, CN106925288A, CN106881104A, CN106861709A, CN106824216A also disclose NiMoW unsupported catalysts, the synthesis method is to dissolve the ammonium salt of Mo and W and adjust the pH, then add the nickel salt solution Carry out precipitation reaction and aging treatment, and finally filter, roast and activate to obtain catalyst. Due to the use of ammonia to adjust the pH during the synthesis process, a large amount of ammonium salts in the waste liquid are not easy to handle, which is easy to cause pollution and waste; and the specific surface area and pore volume of the catalyst are small (less than 110m2 / g and 0.2ml / g, respectively). It is not conducive to the diffusion of reactants in the catalyst during the hydrogenation reaction, and its catalytic activity is limited.

From the above reported results, it can be found that the existing hydrogenation phase catalyst and its synthesis method have the following deficiencies:

1) The specific surface area and pore volume of the catalyst are small, and the activity needs to be improved;

2) The raw materials used in the synthesis are not friendly to the environment;

3) The preparation cost of the catalyst is high. If the introduction of cheap metals reduces the cost, it will interact with the active components and inhibit the catalytic activity;

4) Most of them only pay attention to the hydrodesulfurization activity of the catalyst, and little attention to the hydrodenitrogenation activity of the catalyst.

Based on the above reasons, it is necessary to develop an unsupported hydrorefining catalyst with ultra-high desulfurization and denitrification activity, environmental friendliness, low cost, and easy implementation of large-scale industrial production applications. Previously, my research group disclosed in Chinese patents CN100348700C, CN101153228A, CN101544904B an unsupported hydrogenation catalyst with a metal component of NiMoW, which has high hydrogenation activity and can realize ultra-deep hydrodesulfurization of diesel under milder conditions. However, its high content of active metal components leads to high production costs, and the degree of dispersion of its active components still needs to be improved. Subsequently, my group disclosed in China's patents CN101733120B, CN103657672B, CN105312060A several kinds of NiMMoW unsupported hydrogenation catalysts prepared by introducing cheap metal M, which reduces the active metal content and preparation cost of the catalyst, but due to the cheap metal components and activity There is a certain interaction between the metal components, and their activity still has room for improvement. After that, our research group disclosed in the Chinese patent CN106268850B the introduction of the NiMIVBMoW unsupported hydrogenation catalyst prepared by the IVB group metal MIVB. The degree of dispersion of its active components has been greatly improved, but its preparation cost is still relatively high. In order to reduce the preparation cost of the unsupported hydrorefining catalyst and further improve its desulfurization and denitrification activity, the present invention is improved on the basis of the previous work, and a new multi-metal unsupported hydrorefining catalyst is synthesized to achieve higher desulfurization Denitrification activity and lower production cost.

Summary of the invention

The object of the present invention is to provide a multimetal unsupported hydrorefining catalyst.

Another object of the present invention is to provide a preparation method of the catalyst.

Another object of the present invention is to provide the application of the catalyst in the process of ultra-deep hydrodesulfurization and denitrification of diesel fractions.

The technical features of the catalyst of the present invention include the following aspects:

The hydrorefining catalyst is composed of at least one Group VIII metal oxide, at least one Group IVB metal oxide, at least one + 3-valent metal oxide, and two Group VIB metal oxides, wherein:

The at least one +3 valent metal is selected from one or more than two of Al, Cr, and Fe;

The at least one Group VIII metal is selected from one or two of Ni and Co;

The at least one Group IVB metal is selected from one or two of Ti and Zr;

The two Group VIB metals are selected from Mo and W.

The synthesis method of the hydrorefining catalyst is as follows:

a) Dissolve at least one soluble salt of +3 valent metal in water to prepare a solution, then add an alkaline precipitant solution to react and age, to obtain colloid A containing +3 valent metal;

b) Add at least one group VIII metal and at least one group IVB metal soluble salt to colloid A obtained in step a) to dissolve into a solution, and then add an alkaline precipitant solution for precipitation reaction, and the product is filtered and washed Catalyst precursor B is obtained;

c) Dissolve the soluble salts of two Group VIB metals in water to prepare a solution and add the catalyst precursor B obtained in step b) to the ion exchange reaction. The product is filtered, washed, dried and roasted to obtain the multimetal non-supported Hydrofining catalyst.

In terms of metal oxides, the catalyst contains 10-50wt.% Group VIII metal, 1-30wt.% Group IVB metal, 1-50wt.% +3 valence metal, 5-80wt.% Two VIB Group metals.

The hydrofining catalyst has a specific surface area of 100-350 m2 / g and a pore volume of 0.1-0.6 ml / g.

In the preparation method of the hydrorefining catalyst:

The soluble salt of the at least one + 3-valent metal in step a) is one of aluminum nitrate, aluminum chloride, aluminum sulfate, chromium nitrate, chromium chloride, chromium sulfate, ferric nitrate, ferric chloride, and ferric sulfate Or a combination of two or more;

The precipitation agent in step a) is one or a combination of two or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, ammonia, urea, and ammonium carbonate;

The soluble salt of the at least one Group VIII metal in step b) is one or more of nickel nitrate, nickel acetate, nickel sulfate, nickel chloride, cobalt nitrate, cobalt chloride, cobalt sulfate, and cobalt acetate combination;

The soluble salt of the at least one Group IVB metal in step b) is one or a combination of two or more of titanium nitrate, titanium sulfate, titanium oxysulfate, titanium tetrachloride, zirconium nitrate, zirconium acetate, and zirconium sulfate;

The precipitation agent in step b) is one or a combination of two or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, ammonia, urea, and ammonium carbonate;

The soluble salts of the two Group VIB metals in step c) are one of ammonium heptamolybdate and sodium molybdate and one of ammonium tungstate, ammonium metatungstate and sodium tungstate.

In the preparation method of the hydrorefining catalyst:

In step a), the concentration of the at least one + 3-valent metal soluble salt solution is 0.05-2 mol / L;

Preferably, the concentration of the at least one + 3-valent metal soluble salt solution in step a) is 0.2-1mol / L;

The concentration of the precipitant solution in step a) is 0.01-1mol / L;

Preferably, the concentration of the precipitant solution in step a) is 0.05-0.5mol / L;

The concentration of the at least one group VIII metal soluble salt solution in step b) is 0.01-2mol / L;

Preferably, the concentration of the at least one group VIII metal soluble salt solution in step b) is 0.05-1 mol / L; the concentration of the at least one group IVB metal soluble salt solution in step b) is 0.001-0.5 mol / L;

Preferably, the concentration of the at least one group IVB metal soluble salt solution in step b) is 0.005-0.2 mol / L; the concentration of the precipitant solution in step b) is 0.01-2 mol / L;

Preferably, the concentration of the precipitant solution in step b) is 0.1-1mol / L;

The concentration of the two VIB group metal soluble salt solutions in step c) is 0.01-1mol / L;

Preferably, the concentration of the two group VIB metal soluble salt solutions in step c) is 0.05-0.5 mol / L. In the preparation method of the hydrorefining catalyst:

The reaction and aging temperature described in step a) is 60-100 ° C, the aging time is 2-20h, and the pH of the aging process system is 3-8;

Preferably, the reaction and aging temperature in step a) is 75-95 ° C, the aging time is 5-15h, and the pH of the aging process system is 4-6;

The precipitation reaction temperature in step b) is 40-120 ° C, the reaction time is 2-10h, and the system pH is 7-10 at the end of the reaction;

Preferably, the precipitation reaction temperature in step b) is 60-110 ° C, the reaction time is 2-6h, and the system pH is 8-9 at the end of the reaction;

The ion exchange reaction temperature in step c) is 70-160 ° C, and the reaction time is 8-40h;

Preferably, the ion exchange reaction temperature in step c) is 90-140 ° C, and the reaction time is 30-40h;

The drying temperature in step c) is 80-120 ° C, and the drying time is 6-30h;

Preferably, the drying temperature in step c) is 100-120 ° C, and the drying time is 12-24h;

The calcination temperature in step c) is 300-500 ° C, and the calcination time is 4-20h;

Preferably, the firing temperature in step c) is 300-450 ° C, and the firing time is 16-20h.

The hydrorefining catalyst is used in the ultra-deep hydrodesulfurization and denitrification process of diesel fractions.

Before performing the hydrodesulfurization and denitrification reaction, the hydrorefining catalyst needs to be pretreated as follows:

a) Grinding, kneading and shaping;

b) Pre-vulcanization in situ on the hydrofining fixed-bed reactor under the following conditions:

The curing temperature is 300-450 ℃;

The vulcanizing agent is one or a combination of two or more of H2S, CS2, dimethyl sulfide, and dimethyl disulfide;

The vulcanization atmosphere is H2 and the pressure is 0.05-5MPa;

The vulcanization time is 2-36h.

The conditions of the hydrorefining reaction are:

The temperature is 280-440 ℃;

The volumetric space velocity of the raw material of diesel fraction is 0.1-10h-1.

The reaction atmosphere is hydrogen, the pressure is 1-20MPa, and the volume ratio of hydrogen to diesel fraction raw material is 50-1000V / V.

The hydrorefining catalyst has ultra-high hydrodesulfurization and denitrification activity, and can desulfurize sulfur and nitrogen in the model diesel to less than 10 ppm respectively, and can realize ultra-deep desulfurization and ultra-deep denitrification of diesel fractions.

Compared with the existing well-known technology, the hydrorefining catalyst provided by the present invention has the following advantages:

1) The raw materials used are environmentally friendly, the synthesis process is simple and easy to operate, and industrial production can be achieved;

2) The introduction of cheap +3 valence metal reduces its preparation cost, and at the same time helps to increase the specific surface area of the catalyst particles and optimize their pore structure, which is conducive to the diffusion of reactants during the hydrogenation reaction;

3) By introducing Group IVB metal as a dispersing aid, it can promote the dispersion of the active components, which is beneficial to the formation of more active centers and further enhance the activity of the catalyst;

4) The special introduction method of Group IVB metals can effectively weaken the strong interaction between cheap + 3-valent metals and active metals, avoiding the difficulty of activating some active metals and the resulting decrease in catalyst activity;

5) The hydrorefining catalyst of the present invention exhibits extremely high hydrodesulfurization and hydrodenitrogenation activities. Under relatively mild operating conditions, the sulfur content and nitrogen content of the model diesel can be changed from 800 ppm and 500 ppm, respectively Reduced to below 10ppm, achieved ultra-deep desulfurization and ultra-deep denitrification of model diesel.

BRIEF DESCRIPTION

Figure 1: XRD of the hydrofining catalysts Cat-2, Cat-7, Cat-8, Cat-9, Cat-10 obtained in Examples 2, 7, 8, 9, 10, the results reflect the catalyst Phase structure and degree of dispersion. Among them, the catalyst Cat-2 obtained by the preparation method described in the present invention exhibited the expected active phase structure and better dispersibility. In contrast, for Cat-7 catalysts prepared without introducing Group IVB metals, the degree of dispersion is poor, and due to the strong interaction between the +3 valence metal and Group VIII active metals, the structure of the active phase changes, which is not conducive to the catalyst Activate and inhibit its catalytic performance. When using other methods to introduce the catalyst prepared by the Group IVB metal, two cases will occur: For Cat-9 and Cat-10, although the degree of dispersion of the active phase can be improved, between the +3 valent metal and the Group VIII active metal The interaction cannot be effectively suppressed, resulting in the active phase structure still changing; for Cat-8, although the expected active phase structure is obtained, its diffraction peak is sharper than Cat-2, indicating that its dispersion degree is poor. The above results show that the preparation method described in the present invention can not only improve the degree of dispersion of the active phase in the hydrorefining catalyst, but also effectively suppress the strong interaction between the cheap +3 valent metal and the active component.

Figure 2: The TPR of the hydrorefining catalysts Cat-2, Cat-7, Cat-8, Cat-9, Cat-10 obtained in Examples 2, 7, 8, 9, and 10, the results reflect the catalyst The ease of reduction activation and the interaction between metal components. Among them, the catalyst Cat-2 obtained by the preparation method described in the present invention shows a lower reduction temperature, indicating that it is easier to be reduced and activated. In contrast, for Cat-7, a catalyst prepared without introducing a Group IVB metal, due to the strong interaction between the +3 valence metal and the Group VIII active metal, the reduction temperature is increased, and the catalyst is difficult to be reduced and activated. In addition, for the catalysts Cat-9 and Cat-10 prepared by introducing other Group IVB metals using other methods, the reduction temperature is also higher due to the strong interaction between the + 3-valent metal and the Group VIII active metal, and Same as Cat-7. For the Cat-8 catalyst prepared by introducing the IVB metal by other methods, although the strong interaction between the +3 valence metal and the VIII active metal is suppressed, the poor dispersion of the catalyst is not conducive to the active components and Due to the contact of the reducing agent, the reduction temperature is also higher than Cat-2. The above results indicate that the preparation method described in the present invention can effectively suppress the strong interaction between the + 3-valent inexpensive metal and the active component, making the catalyst more easily reduced and activated.

detailed description

To further illustrate the present invention, the following examples are listed, but do not limit the scope of the invention defined by the claims.

The present invention proposes a multi-metal unsupported hydrogenation consisting of at least one + 3-valent metal oxide, at least one Group VIII metal oxide, at least one Group IVB metal oxide, and two Group VIB metal oxides based on experimental results Refined catalyst and preparation method thereof, wherein the +3 valent metal is selected from Al, Cr, Fe, the group VIII metal is selected from Ni, Co, the group IVB metal is selected from Ti, Zr, and the two group VIB The metal is selected from Mo and W. Here, for simplicity, some examples of metal selection are listed, but this does not mean that the remaining metal selections cannot implement the present invention.

Example 1

This example illustrates the preparation of a multi-metal unsupported hydrorefining catalyst with metal components of Al, Ni, Ti, Mo, and W using the synthesis method of the present invention:

a) Weigh 73.55g of aluminum nitrate nonahydrate, add 300ml of deionized water to make a solution, then weigh 11.76g of urea, add 500ml of deionized water to make a solution, and then stir and mix the two solutions at a constant temperature of 90 ℃ And aging for 12h to get colloid A;

b) Weigh 136.20g nickel nitrate hexahydrate and 10.00g titanyl sulfate, add to colloid A obtained in step a) and stir to dissolve, then weigh 58.30g sodium carbonate, add 600ml of deionized water to make a solution, and then at 100 ℃ The two solutions were stirred and mixed under constant temperature for 6 hours, filtered and washed to obtain catalyst precursor B;

c) Weigh 23.48g ammonium heptamolybdate and 32.97g ammonium metatungstate (containing 0.133mol and Mo respectively), add 500ml of deionized water to make a solution, and add the catalyst obtained in step b) at a constant temperature of 90 ℃ Body B reacted for 36h, then filtered and washed, dried at 120 ° C for 12h and calcined at 400 ° C for 20h to obtain a polymetallic unsupported hydrorefining catalyst, denoted as Cat-1.

As determined by low-temperature nitrogen adsorption, the specific surface area of Cat-1 is 247m2 / g and the pore volume is 0.43ml / g.

Example 2

This example illustrates the preparation of a multimetal unsupported hydrorefining catalyst with Cr, Ni, Ti, Mo, and W metal components using the synthesis method of the present invention:

Except that 52.66 g of chromium nitrate nonahydrate and 7.92 g of urea were used instead of 73.55 g of aluminum nitrate nonahydrate and 11.76 g of urea used in step a) of Example 1, hydrofining was prepared in the same manner as described in Example 1. The catalyst is referred to as Cat-2.

As determined by low-temperature nitrogen adsorption, the specific surface area of Cat-2 is 184m2 / g and the pore volume is 0.32ml / g.

Example 3

This example illustrates the preparation of a multimetal unsupported hydrorefining catalyst with metal components Fe, Ni, Ti, Mo, W using the synthesis method of the present invention:

Except that 50.50 g of ferric nitrate nonahydrate and 7.50 g of urea were used instead of 73.55 g of aluminum nitrate nonahydrate and 11.76 g of urea used in step a) of Example 1, hydrofining was prepared in the same manner as described in Example 1. The catalyst is referred to as Cat-3.

As determined by low-temperature nitrogen adsorption, the specific surface area of Cat-3 is 221 m2 / g, and the pore volume is 0.38 ml / g.

Example 4

This example illustrates the preparation of a multimetal unsupported hydrorefining catalyst with metal components of Al, Ni, Zr, Mo, W using the synthesis method of the present invention:

A hydrofining catalyst, designated Cat-4, was prepared in the same manner as described in Example 1 except that 17.42 g of zirconium nitrate pentahydrate was used instead of 10.00 g of titanyl sulfate used in step b) of Example 1.

As determined by low-temperature nitrogen adsorption, the specific surface area of Cat-4 is 269m2 / g and the pore volume is 0.47ml / g.

Example 5

This example illustrates the preparation of a multimetal unsupported hydrorefining catalyst with Cr, Ni, Zr, Mo, and W components using the synthesis method of the present invention:

In addition to using 52.66 g of chromium nitrate nonahydrate and 7.92 g of urea instead of 73.55 g of aluminum nitrate nonahydrate and 11.76 g of urea used in step a) of Example 1, respectively, and 17.42 g of zirconium nitrate pentahydrate in step b) of Example 1 The 10.00 g of titanyl sulfate used was prepared in the same manner as described in Example 1 to obtain a hydrorefining catalyst, designated as Cat-5.

As determined by low-temperature nitrogen adsorption, the specific surface area of Cat-5 is 171 m2 / g and the pore volume is 0.29 ml / g.

Example 6

This example illustrates the preparation of a multimetal unsupported hydrorefining catalyst with metal components Fe, Ni, Zr, Mo, W using the synthesis method of the present invention:

In addition to using 50.50 g of ferric nitrate nonahydrate and 7.50 g of urea to replace 73.55 g of aluminum nitrate nonahydrate and 11.76 g of urea used in step a) of Example 1, respectively, and 17.42 g of zirconium nitrate pentahydrate to replace step b) of Example 1 The 10.00 g of titanyl sulfate used was prepared in the same manner as described in Example 1 to obtain a hydrorefining catalyst, designated as Cat-6.

As determined by low temperature nitrogen adsorption, Cat-6 has a specific surface area of 194m2 / g and a pore volume of 0.34ml / g.

Example 7

This example illustrates the use of the synthesis method described in the present invention, but omitting the IVB group metal component added in step b) to prepare a multi-metal unsupported hydrorefining catalyst with metal components of Cr, Ni, Mo, and W, For comparison:

a) Weigh 52.66g of chromium nitrate nonahydrate, add 300ml of deionized water to make a solution, then weigh 7.92g of urea, add 500ml of deionized water to make a solution, and then stir and mix the two solutions at a constant temperature of 90 ℃ And aging for 12h to get colloid A;

b) Weigh 136.20g nickel nitrate hexahydrate, add to colloid A obtained in step a) and stir to dissolve, then weigh 58.30g sodium carbonate, add 600ml of deionized water to make a solution, and then mix the two at a constant temperature of 100 ℃ The solution was stirred and mixed for 6 hours, filtered and washed to obtain catalyst precursor B;

c) Weigh 23.48g ammonium heptamolybdate and 32.97g ammonium metatungstate (containing 0.133mol and Mo respectively), add 500ml of deionized water to make a solution, and add the catalyst obtained in step b) at a constant temperature of 90 ℃ Body B reacted for 36h, then filtered and washed, dried at 120 ° C for 12h and calcined at 400 ° C for 20h to obtain a polymetallic unsupported hydrorefining catalyst, denoted as Cat-7.

As determined by low-temperature nitrogen adsorption, the specific surface area of Cat-7 is 177m2 / g and the pore volume is 0.31ml / g.

Example 8

This example illustrates a multimetal unsupported hydrorefining catalyst with the same composition as Example 2, but the introduction method of Group IVB metal is different from the method described in the present invention for comparison:

a) Weigh 52.66g of chromium nitrate nonahydrate and 10.00g of titanyl sulfate, add 300ml of deionized water to make a solution, and then weigh 7.92g of urea, add 500ml of deionized water to make a solution, and then place it at a constant temperature of 90 ℃ The two solutions were stirred and mixed and reacted for 12 hours to obtain colloid A;

c) Weigh 23.48g ammonium heptamolybdate and 32.97g ammonium metatungstate (containing 0.133mol and Mo respectively), add 500ml of deionized water to make a solution, and add the catalyst obtained in step b) at a constant temperature of 90 ℃ Body B reacted for 36h, then filtered and washed, dried at 120 ° C for 12h and calcined at 400 ° C for 20h, to obtain a multi-metal unsupported hydrorefining catalyst, denoted as Cat-8.

As measured by low temperature nitrogen adsorption, the specific surface area of Cat-8 is 189m2 / g and the pore volume is 0.33ml / g.

Example 9

c) Weigh 10.00g of titanyl sulfate, add 200ml of deionized water to make a solution, then add the catalyst precursor B obtained in step b) to mix into a slurry, then weigh 15.00g of sodium carbonate, add 600ml of deionized water to make a solution The solution, and the two solutions were stirred and mixed under a constant temperature of 100 ° C for 6 hours, filtered and washed to obtain catalyst precursor C;

d) Weigh 23.48g ammonium heptamolybdate and 32.97g ammonium metatungstate (containing 0.133mol and Mo respectively), add 500ml of deionized water to make a solution, and add the catalyst obtained in step c) at a constant temperature of 90 ℃ Bulk C reacted for 36h, then filtered and washed, dried at 120 ° C for 12h and calcined at 400 ° C for 20h to obtain a multimetal unsupported hydrorefining catalyst, denoted as Cat-9.

As determined by low-temperature nitrogen adsorption, the specific surface area of Cat-9 is 179m2 / g and the pore volume is 0.31ml / g.

Example 10

a) Weigh 52.66g chromium nitrate nonahydrate, 136.20g nickel nitrate hexahydrate and 10.00g titanyl sulfate, add 500ml deionized water to make a solution, then weigh 7.92g urea and 58.30g sodium carbonate, add 600ml deionized water Form a solution, and then mix and react the two solutions under constant temperature condition of 100 ℃ and age for 12h, filter and wash to obtain catalyst precursor B;

b) Weigh 23.48g ammonium heptamolybdate and 32.97g ammonium metatungstate (containing 0.133mol and Mo respectively), add 500ml of deionized water to make a solution, and add the catalyst obtained in step a) at a constant temperature of 90 ℃ Body A reacted for 36h, then filtered and washed, dried at 120 ° C for 12h and calcined at 400 ° C for 20h to obtain a multimetal unsupported hydrorefining catalyst, denoted as Cat-10.

As determined by low-temperature nitrogen adsorption, the specific surface area of Cat-10 is 238 m2 / g, and the pore volume is 0.41 ml / g.

Example 11

This example illustrates the performance evaluation of multimetal non-supported hydrorefining catalysts for model diesel hydrodesulfurization and hydrodenitrogenation:

a) Form the polymetallic unsupported hydrorefining catalysts Cat-1 to Cat-10 prepared in Examples 1-10, then weigh 1.0 g of the shaped catalyst in a fixed-bed reactor, and use 10 vol.% H2S The H2 atmosphere is pre-vulcanized at a temperature of 400 ° C and a pressure of 0.1MPa, and the treatment time is 4h;

b) A certain amount of 4,6-DMDBT and quinoline are dissolved in decahydronaphthalene solvent to prepare a model diesel with a sulfur content of 800 ppm and a nitrogen content of 500 ppm, which is used to investigate the hydrodesulfurization and hydrodenitrogenation reactions of the catalyst performance. Under the condition of temperature 330 ℃ and hydrogen pressure 3.5MPa, the model diesel with a sulfur content of 800ppm and nitrogen content of 500ppm was introduced for hydrodesulfurization and denitrification, in which the volume space velocity of the model diesel was 9h-1, H2 and the model The volume ratio of diesel fuel is 600Nm3 / m3.

c) The sulfur content and nitrogen content of the sample after the reaction were measured by ANTEK sulfur determination instrument and ANTEK nitrogen determination instrument, the results are shown in Table 1. In addition, the desulfurization activity and denitrification activity of the catalyst prepared by the present invention are expressed by relative desulfurization activity and relative denitrification activity: the desulfurization activity and denitrification activity of the commercial reference catalyst are 100, respectively. The ratio of desulfurization activity and denitrification activity is the relative desulfurization activity and relative denitrification activity of the catalyst in the present invention. The relative desulfurization activity and relative denitrification activity are calculated according to the following formulas:

Relative desulfurization activity = 100 × [(1 / Sp) ^0.65- (1 / Sf) ^0.65 ] / [(1 / Spr) ^0.65- (1 / Sf) ^0.65 ]

Relative denitrification activity = 100 × [(1 / Np) ^0.65- (1 / Nf) ^0.65 ] / [(1 / Npr) ^0.65- (1 / Nf) ^0.65 ]

among them:

Sf represents the sulfur content of the model diesel;

Spr represents the sulfur content of the product of model diesel after hydrorefining with a commercial reference catalyst;

Sp represents the sulfur content of the product of model diesel after hydrorefining by the catalyst of the present invention;

Nfr represents the nitrogen content of the model diesel;

Npr represents the nitrogen content of the product of model diesel after being hydrorefined by a commercial reference catalyst;

Np represents the nitrogen content of the product of model diesel oil after hydrorefining by the catalyst of the present invention.

Table 1. Hydrodesulfurization and hydrodenitrogenation reactivity of hydrofinishing catalysts:

Claims

A multi-metal unsupported hydrorefining catalyst is composed of at least one Group VIII metal oxide, at least one Group IVB metal oxide, at least one + 3-valent metal oxide, and two Group VIB metal oxides, wherein :

The at least one +3 valent metal is selected from one or more than two of Al, Cr, and Fe;

The at least one Group VIII metal is selected from one or two of Ni and Co;

The at least one Group IVB metal is selected from one or two of Ti and Zr;

The two Group VIB metals are selected from Mo and W;

The synthesis method of the catalyst is as follows:

a) Dissolve at least one soluble salt of +3 valent metal in water to prepare a solution, then add an alkaline precipitant solution to react and age, to obtain colloid A containing +3 valent metal;

b) Add at least one group VIII metal and at least one group IVB metal soluble salt to colloid A obtained in step a) to dissolve into a solution, and then add an alkaline precipitant solution for precipitation reaction, and the product is filtered and washed Catalyst precursor B is obtained;

c) Dissolve the soluble salts of two Group VIB metals in water to prepare a solution and add the catalyst precursor B obtained in step b) to the ion exchange reaction. The product is filtered, washed, dried and roasted to obtain the multimetal non-supported Hydrofining catalyst.
The hydrorefining catalyst according to claim 1, characterized in that:

In terms of metal oxides, the catalyst contains 10-50wt.% Group VIII metal, 1-30wt.% Group IVB metal, 1-50wt.% +3 valence metal, 5-80wt.% Two VIB Group metals.
The hydrorefining catalyst according to claim 1, characterized in that:

The hydrofining catalyst has a specific surface area of 100-350 m2 / g and a pore volume of 0.1-0.6 ml / g.
The hydrorefining catalyst according to claim 1, characterized in that:

The soluble salt of the at least one + 3-valent metal in step a) is one of aluminum nitrate, aluminum chloride, aluminum sulfate, chromium nitrate, chromium chloride, chromium sulfate, ferric nitrate, ferric chloride, and ferric sulfate Or a combination of two or more;

The precipitation agent in step a) is one or a combination of two or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, ammonia, urea, and ammonium carbonate;

The soluble salt of the at least one Group VIII metal in step b) is one or more of nickel nitrate, nickel acetate, nickel sulfate, nickel chloride, cobalt nitrate, cobalt chloride, cobalt sulfate, and cobalt acetate combination;

The soluble salt of the at least one Group IVB metal in step b) is one or a combination of two or more of titanium nitrate, titanium sulfate, titanium oxysulfate, titanium tetrachloride, zirconium nitrate, zirconium acetate, and zirconium sulfate;

The precipitation agent in step b) is one or a combination of two or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, ammonia, urea, and ammonium carbonate;

The soluble salts of the two Group VIB metals in step c) are one of ammonium heptamolybdate and sodium molybdate and one of ammonium tungstate, ammonium metatungstate and sodium tungstate.
The hydrorefining catalyst according to claim 1, characterized in that:

In step a), the concentration of the at least one + 3-valent metal soluble salt solution is 0.05-2 mol / L;

The concentration of the precipitant solution in step a) is 0.01-1mol / L;

The concentration of the at least one group VIII metal soluble salt solution in step b) is 0.01-2mol / L;

The concentration of the at least one group IVB metal soluble salt solution in step b) is 0.001-0.5mol / L;

The concentration of the precipitant solution in step b) is 0.01-2mol / L;

The concentration of the two group VIB metal soluble salt solutions in step c) is 0.01-1mol / L.
The hydrorefining catalyst according to claim 1, characterized in that:

The reaction and aging temperature described in step a) is 60-100 ° C, the aging time is 2-20h, and the pH of the aging process system is 3-8;

The precipitation reaction temperature in step b) is 40-120 ° C, the reaction time is 2-10h, and the system pH is 7-10 at the end of the reaction;

The ion exchange reaction temperature in step c) is 70-160 ° C, and the reaction time is 8-40h;

The drying temperature in step c) is 80-120 ° C, and the drying time is 6-30h;

The firing temperature in step c) is 300-500 ° C, and the firing time is 4-20h.
An application of the multimetal unsupported hydrofinishing catalyst according to any one of claims 1 to 6 in the process of ultra-deep hydrodesulfurization and denitrification of diesel fractions.
The use of the hydrorefining catalyst according to claim 7, characterized in that:

Before performing the hydrodesulfurization and denitrification reaction, the hydrorefining catalyst needs to be pretreated as follows:

a) Grinding, kneading and shaping;

b) Pre-vulcanization in situ on the hydrofining fixed-bed reactor under the following conditions:

The curing temperature is 300-450 ℃;

The vulcanizing agent is one or a combination of two or more of H2S, CS2, dimethyl sulfide, and dimethyl disulfide;

The vulcanization atmosphere is H2 and the pressure is 0.05-5MPa;

The vulcanization time is 2-36h.
The use of the hydrorefining catalyst according to claim 7, characterized in that:

The conditions of the hydrorefining reaction are:

The temperature is 280-440 ℃;

The volumetric space velocity of the raw material of diesel fraction is 0.1-10h-1.

The reaction atmosphere is hydrogen, the pressure is 1-20MPa, and the volume ratio of hydrogen to diesel fraction raw material is 50-1000V / V.