CN1470327A - A kind of preparation method of metal nitride catalyst and catalyst - Google Patents

Abstract

The invention provides an active metal nitride catalyst for desulfurization, denitrogenation and olefin reduction. The nitrides therein can exist alone in the form of compounds, or can be loaded on carrier materials, and the loading amount of the nitrides is 15%-35% by weight. The catalyst has a pore volume of 0.29-0.63 cm ³ /g and a specific surface area of 165-232 m ² /g. At the same time, the invention also discloses a method for preparing the nitride catalyst, which uses hydrogen and nitrogen as reducing agents and adopts a temperature-programmed reduction method. The preparation method has strong stability, is not prone to hydrothermal sintering, and has relatively low requirements on equipment.

Description

A kind of metal nitride catalyst agent preparation method and catalyst

Technical field

The preparation method who the present invention relates to a kind of nitride catalyst reaches with the prepared a kind of catalyst of this method, specifically a kind of nitride hydrodenitrogeneration, hydrodesulfurization and hydrogenation and olefin hydrocarbon removal catalyst.

Background technology

Hydrocarbons hydrogenation is refining to be technical process necessary in the petrochemical industry, its objective is organic sulfur compound and the organic nitrogen compound removed in the feedstock oil, to satisfy the high-quality requirement of oil product.Along with the sustainable growth of national economy, the oil product demand is increased year by year, crude oil heaviness, inferiorization trend are also serious day by day, cause oil product (gasoline, diesel oil, kerosene) harmful substance (SO in application process _x, NO _xDeng) discharge capacity significantly increase, particularly the urban air pollution problem that causes of motor-vehicle tail-gas is serious day by day, has caused the close attention and the great attention of government and environmental administration.Therefore, must carry out deep hydrofinishing,, improve the quality of oil product to remove impurity such as sulphur, nitrogen and aromatic hydrocarbons wherein to crude oil fractions.

For a long time, people have carried out deeply the desulfurization of fuel oil and denitrogenation hydrogenation catalyst for refining and method and extensive studies has proposed many desulfurization removing nitric Hydrobon Catalyst And Its Preparation Method and hydrogenation desulfurization and denitrogenation methods with high catalytic activity always.

At present, industrial hydrodesulfurization commonly used (HDS) hydrodenitrogeneration (HDN) catalyst is cobalt-molybdenum or nickel-molybdenum catalyst, sometimes also add some auxiliary agents,, can't satisfy the requirement of oil product deep desulfuration, denitrogenation though these catalyst have certain desulfurization removing nitric activity as phosphorus and so on.

Chinese patent CN1067654C discloses a kind of double elements bigger serface transition metal nitride, this metal nitride is to be mixed by the nitrate that contains transition metal or sulfate solution and Cr, Mo or W acid or Cr, Mo or W acid aqueous ammonium, make support type or non-loading type double elements slaine or composite oxides by coprecipitation or infusion process, again with double elements slaine or the logical NH of composite oxides ₃Carry out temperature programming, react under final nitriding temperature 600-750 ℃ and make.This method NH ₃Be nitridizing agent, and NH ₃In nitridation process, be easy to take place hydrothermal sintering, make the specific surface of catalyst be restricted, and can not obtain the catalyst of Large ratio surface.And this method for the requirement of equipment performance also than higher, simultaneously poor stability, be not easy to operation.In addition, also can cause pollution to a certain degree, be unfavorable for environmental protection.

Summary of the invention

One of purpose of the present invention is, a kind of preparation method of metal nitride catalyst agent is provided.Another object of the present invention is to, a kind of metal nitride catalyst agent that has than bigger serface is provided.

The invention provides a kind of metal nitride catalyst agent, catalyst is an active component with the nitride of group vib and/or group VIII metal, and loads on the carrier material, and the pore volume of catalyst is 0.29-0.63cm ³/ g, specific area is 165-232m ²/ g, discloseder nitride catalyst has great advantage.

Wherein the load capacity of nitride is 15%-35% by weight.

Described nitride is tungsten nitride or nickel oxide tungsten preferably.

Described carrier material can be any porous mass with suitable specific area.Comprise:

Metal oxide, as: γ-Al ₂O ₃, TiO ₂, TiO ₂-Al ₂O ₃Deng; Natural clay, as: bentonite, kaolin etc.; Molecular sieve, as: phosphate aluminium molecular sieve, ZSM5 type molecular sieve, MCM molecular sieve etc.

Wherein best carrier is: γ-Al ₂O ₃, TiO ₂, TiO ₂-Al ₂O ₃Or phosphate aluminium molecular sieve.

Simultaneously, the present invention also provides a kind of preparation method of metal nitride catalyst agent, adopts group vib and/or group VIII metallic compound temperature-programmed reduction method to prepare catalyst of the present invention, and used reducing agent is hydrogen and nitrogen in the temperature programming process.

Concrete preparation process is:

1, preparation catalyst precarsor: with group vib and/or the dissolving of group VIII slaine, drying was also calcined 4 hours under 673K-823K at least, preferably 4-10 hour, made composite oxides;

2, above-mentioned composite oxides are carried out temperature programmed reduction, preparation nitride: in the presence of hydrogen and nitrogen, be warming up to 823K～923K, and under this temperature, reduced at least 2 hours, preferably 2-4 hour, and at room temperature, passivation is at least 8 hours in the inert gas atmosphere, preferably 8-15 hour, obtain catalyst of the present invention.

Said group vib and/or group VIII slaine in the above-mentioned steps 1 better are tungstates or nickel salt, preferably ammonium metatungstate, ammonium tungstate, nickel nitrate or nickelous carbonate.Also the reactive metal aqueous solution can be impregnated on the carrier material dry again in the step 1 after the dissolving.

Described carrier material can be any porous carrier materials with suitable specific area, comprising: metal oxide, as: γ-Al ₂O ₃, TiO ₂Deng; Natural clay, as: bentonite, kaolin etc.; Molecular sieve, as: ZSM5 type molecular sieve, phosphate aluminium molecular sieve, MCM series molecular sieve etc.

Wherein best carrier is: γ-Al ₂O ₃, TiO ₂, TiO ₂-Al ₂O ₃Or phosphate aluminium molecular sieve.

Said 823K～the 923K that is warming up in the step 2 can adopt linear mode to heat up or temperature-gradient method.Linear mode heats up and is the heating rate intensification with 0.5-3K/min; The heating mode of segmentation rises to 523K～723K for first heating rate with 3-4K, and the heating rate with 0.5-1K is warming up to 823K～923K again.

Said inert gas is preferably nitrogen or helium in the step 2, preferably contains the nitrogen of oxygen 0.5-1%.

It is nitridizing agent that the present invention adopts nitrogen and hydrogen, has synthesized tungsten nitride and nickel oxide tungsten Hydrobon catalyst.Compare with sulfide catalyst in the past, this type of catalyst has higher specific area and higher hydrodesulfurization and hydrodenitrogeneration catalytic activity, can remove the big molecule sulfur-containing compound of condensed-nuclei aromatics.Because nitride catalyst does not need the pre-vulcanization process of tradition sulfuration catalyst series before carrying out hydrodesulfurization, denitrification reaction, belong to process for cleanly preparing; And nitridizing agent adopts hydrogen and nitrogen in the preparation process, and than being that nitridizing agent more meets environmental protection requirement with ammonia, and to the requirement reduction of equipment, stable production process is better.

The specific embodiment

Embodiment 1 preparation non-loading type tungsten nitride (W ₂N) preparation method of catalyst 11. catalyst precarsors:

Getting the 13.04g ammonium metatungstate is dissolved in the 200ml distilled water; Water bath method; The material that obtains is dry 10h under 393K (120 ℃) temperature; At 773K (500 ℃) temperature lower calcination 6h.2. the temperature programmed reduction tungsten oxide prepares tungsten nitride (W ₂N)

Hydrogen stream (99.999%, 90ml/min) and nitrogen stream (99.999%, the 18ml/min) tungsten oxide precursor of the above-mentioned preparation of reduction down, temperature is elevated to 923K (650 ℃) with linear mode, programming rate 1K/min; After the reduction, the sample of black is at room temperature at 1%O ₂/ N ₂Passivation 10h (before being exposed to air) in the gas (30ml/min).N ₂Available He replaces.

Embodiment 2 preparation non-loading type tungsten nitride (W ₂N) preparation method of catalyst 21. catalyst precarsors:

Claim the 13.04g ammonium metatungstate to be dissolved in the 200ml distilled water; Water bath method; The material that obtains is dry 10h under 393K (120 ℃) temperature; Prepare tungsten nitride (W at 773K (500 ℃) temperature lower calcination 6h.2. temperature programmed reduction tungsten oxide ₂N)

Hydrogen stream (99.999%, 90ml/min) and nitrogen stream (99.999%, the 18ml/min) tungsten oxide precursor of the above-mentioned preparation of reduction down, programming rate is raised to 623K (350 ℃) with 3K/min earlier and is raised to 923K (650 ℃) with 1K/min again; After reduction, the sample of black is at room temperature at 1%O ₂/ N ₂Passivation 10h (before being exposed to air) in the gas (30ml/min).N ₂Available He replaces.

Embodiment 3 support type nitrogenize tungsten (W ₂N/ γ-Al ₂O ₃) preparation method of Preparation of catalysts 11. catalyst precarsors:

Taking by weighing the 2.165g ammonium metatungstate is dissolved in the 100ml distilled water; Claim 3.46 gram γ-Al ₂O ₃, be immersed in the above-mentioned solution and spend the night; Water bath method; The material that obtains is dry 10h under 393K (120 ℃) temperature; At 773K (500 ℃) temperature lower calcination 6h; 2. the temperature programmed reduction tungsten oxide prepares tungsten nitride (W ₂N)

Hydrogen stream (99.999%, 90ml/min) and nitrogen stream (99.999%, the 18ml/min) material after the above-mentioned calcining of reduction down, temperature is elevated to 923K (650 ℃) with linear mode, programming rate 1K/min; After the reduction, the sample of black is at room temperature at 1%O ₂/ N ₂Passivation 10h (before being exposed to air) in the gas (30ml/min), N ₂Available He replaces;

The load capacity of tungsten nitride is about 24% (weight meter);

The specific surface of catalyst sample is 197m ²/ g, pore volume 0.53cm ³/ g.

4 years type tungsten nitrides of embodiment (W ₂N/ γ-Al ₂O ₃) preparation method of Preparation of catalysts 21. catalyst precarsors:

Taking by weighing the 2.165g ammonium metatungstate is dissolved in the 100ml distilled water; Claim 3.46 gram γ-Al ₂O ₃, be immersed in the above-mentioned solution and spend the night; Water bath method; The material that obtains is dry 10h under 393K (120 ℃) temperature; At 773K (500 ℃) temperature lower calcination 6h; 2. the temperature programmed reduction tungsten oxide prepares tungsten nitride (W ₂N)

Hydrogen stream (99.999%, 90ml/min) and nitrogen stream (99.999%, the 18ml/min) material after the above-mentioned calcining of reduction down, programming rate is raised to 623K (350 ℃) with 3K/min earlier and is raised to 923K (650 ℃) with 1K/min again; After reduction, the sample of black is at room temperature at 1%O ₂/ N ₂Passivation 10h (before being exposed to air) in the gas (30ml/min).N ₂Available He replaces;

The load capacity of tungsten nitride is about 24% (weight meter);

The specific surface of catalyst sample is 216m ²/ g, pore volume 0.58cm ³/ g.

Embodiment 5 non-loading type tungsten nitride (W ₂N) mensuration of catalyst HDS activity

Stagnation pressure 3.0MPa is carried out in model compound thiophene hydrodesulfurization catalysis experiment on the continuous micro-reactor of high pressure.1) gets 1mlW ₂The N catalyst; 2) catalyst will activate before using, at 673K and 0.1MPa H ₂/ N ₂Or H ₂Activation 4h is with the W from passivation ₂The N catalyst surface is removed O ₂3) liquid reactants is thiophene content 5% cyclohexane solution, squeezes in the reactor by high-pressure pump; 4) product stream is used the chromatogram that has fid detector by on-line analysis; 5) desulfurization degree is up to 93%.

Embodiment 6 non-loading type tungsten nitride (W ₂N) mensuration of catalyst HDN activity

The hydrodenitrogeneration catalysis experiment of model compound pyridine is being carried out stagnation pressure 3.0MPa on the micro-reactor continuously.1) measures 1ml W ₂The N catalyst; 2) catalyst will activate before using, at 673K and 0.1MPa H ₂/ N ₂Or H ₂Activation 4h is with the W from passivation ₂The N catalyst surface is removed O ₂3) liquid reactants is thiophene content 5% cyclohexane solution, squeezes in the reactor by high-pressure pump; 4) product stream is used the chromatogram that has fid detector by on-line analysis; 5) denitrification percent is up to 87%.

Embodiment 7 support type nitrogenize tungsten (W ₂N/ γ-Al ₂O ₃) mensuration of catalyst HDS activity

The model compound thiophene gets hydrodesulfurization catalysis experiment and is carrying out stagnation pressure 3.0MPa on the micro-reactor continuously.1) measures 1ml W ₂N/ γ-Al ₂O ₃Catalyst; 2) catalyst will activate before using, at 673K and 0.1MPa H ₂/ N ₂Or H ₂Activation 4h is with the W from passivation ₂The N catalyst surface is removed O ₂3) liquid reactants is thiophene content 5% cyclohexane solution, squeezes in the reactor by high-pressure pump; 4) product stream is used the chromatogram that has fid detector by on-line analysis; 5) desulfurization degree is up to 96%.The preparation method of preparation 1. catalyst precarsors of embodiment 8 non-loading type nickel oxide tungsten catalysts

Taking by weighing 0.5449g nickel nitrate and 1.968g ammonium metatungstate is dissolved in the 200ml distilled water; Water bath method; The material that obtains is dry 10h under 393K (120 ℃) temperature; At 773K (500 ℃) temperature lower calcination 6h.2. temperature programmed reduction prepares catalyst

Hydrogen stream (99.999%, 90ml/min) and nitrogen stream (99.999%, the 18ml/min) catalyst precarsor of the above-mentioned preparation of reduction down, temperature is elevated to 923K (650 ℃) with linear mode, programming rate 1K/min.After reduction, the sample of black is at room temperature at 1%O ₂/ N ₂Passivation 10h (before being exposed to air) in the gas (30ml/min).N ₂Available He replaces.

The preparation method of preparation 1. catalyst precarsors of embodiment 9 support type nitrogenize nickel tungsten catalysts

Taking by weighing 0.5449g nickel nitrate and 1.968g ammonium metatungstate is dissolved in the 200ml distilled water; Claim 3.46 gram γ-Al ₂O ₃, be immersed in the above-mentioned solution and spend the night; Water bath method; The material that obtains is dry 10h under 393K (120 ℃) temperature; At 773K (500 ℃) temperature lower calcination 6h; 2. temperature programmed reduction prepares catalyst

Hydrogen stream (99.999%, 90ml/min) and nitrogen stream (99.999%, the 18ml/min) material after the above-mentioned calcining of reduction down, temperature is elevated to 923K (650 ℃) with linear mode, programming rate 1K/min; After reduction, the sample of black is at room temperature at 1%O ₂/ N ₂Passivation 10h (before being exposed to air) in the gas (30ml/min).N ₂Available He replaces; The load capacity of nickel oxide tungsten is about 24% (weight meter);

The specific surface of catalyst sample is 227m ²/ g, pore volume 0.63cm ³/ g.

The mensuration of embodiment 10 non-loading type nickel oxide tungsten catalyst HDS activity

The model compound thiophene gets hydrodesulfurization catalysis experiment and is carrying out stagnation pressure 3.0MPa on the micro-reactor continuously.

1) measures 1ml non-loading type nickel oxide tungsten catalyst;

2) catalyst will activate before using, at 673K and 0.1MPa H ₂/ N ₂Or H ₂Activation 4h, with

Remove O from the passivated catalyst surface ₂

3) liquid reactants is thiophene content 5% cyclohexane solution, squeezes in the reactor by high-pressure pump;

4) product stream is used the chromatogram that has fid detector by on-line analysis;

5) desulfurization degree is up to 95%.

The mensuration of embodiment 11 non-loading type nickel oxide tungsten catalyst HDN activity

The hydrodenitrogeneration catalysis experiment of model compound pyridine is being carried out stagnation pressure 3.0MPa on the micro-reactor continuously.

1) gets 1ml non-loading type nickel oxide tungsten catalyst;

2) catalyst will activate before using, at 673K and 0.1MPa H ₂/ N ₂Or H ₂Activation 4h,

To remove O from the passivated catalyst surface ₂

3) liquid reactants is thiophene content 5% cyclohexane solution, squeezes in the reactor by high-pressure pump;

4) product stream is used the chromatogram that has fid detector by on-line analysis;

5) denitrification percent is up to 90%.The mensuration (embodiment 12) of 12 support type nitrogenize nickel tungsten catalyst HDS activity

The hydrodesulfurization catalysis experiment of model compound thiophene is being carried out stagnation pressure 3.0MPa on the micro-reactor continuously.

1) measures 1ml support type nitrogenize nickel tungsten catalyst;

2) catalyst will activate before using, at 673K and 0.1MPa H ₂/ N ₂Or H ₂Activation 4h,

To remove O from the passivated catalyst surface ₂

3) liquid reactants is thiophene content 5% cyclohexane solution, squeezes in the reactor by high-pressure pump;

4) product stream is used the chromatogram that has fid detector by on-line analysis;

5) desulfurization degree is up to 97%.

The mensuration of embodiment 13 support type nitrogenize nickel tungsten catalyst HDN activity

The hydrodenitrogeneration catalysis experiment of model compound pyridine is being carried out stagnation pressure 3.0MPa on the micro-reactor continuously.

1) 1ml support type nitrogenize nickel tungsten catalyst;

2) catalyst will activate before using, at 673K and 0.1MPa H ₂/ N ₂Or H ₂The activation 4h, with from

O is removed on the passivated catalyst surface ₂

3) liquid reactants is thiophene content 5% cyclohexane solution, squeezes in the reactor by high-pressure pump;

4) product stream is used the chromatogram that has fid detector by on-line analysis;

5) denitrification percent is up to 98%.

By above experimental data as seen, nitride catalyst can be prepared, and the load type nitrogen compound catalyst of Large ratio surface can be prepared with higher desulfurization, denitrification activity with method of the present invention.

Claims (10)

1. a metal nitride catalyst agent is characterized in that, is active component with the nitride of group vib and/or group VIII metal, and loads on the carrier material that the pore volume of catalyst is 0.29-0.63cm ³/ g, specific area is 165-232m ²/ g.

2. according to the described catalyst of claim 1, it is characterized in that the load capacity of nitride is 15%-35% by weight.

3. according to the described catalyst of claim 1, it is characterized in that nitride wherein is tungsten nitride or nickel oxide tungsten.

4. according to claim 1,2 or 3 described catalyst, it is characterized in that carrier material wherein is one or more in metal oxide, molecular sieve, silica gel, diatomite, the natural clay.

5. according to the described catalyst of claim 4, it is characterized in that metal oxide wherein is γ-Al ₂O ₃, TiO ₂TiO ₂-Al ₂O ₃Natural clay is bentonite, kaolin; Molecular sieve is phosphate aluminium molecular sieve, ZSM5 type molecular sieve, MCM molecular sieve.

6. the preparation method of a metal nitride catalyst agent adopts group vib and/or group VIII metallic compound temperature-programmed reduction method to prepare catalyst, it is characterized in that used reducing agent is hydrogen and nitrogen in the temperature programming process.

7. according to the described preparation method of claim 6, it is characterized in that concrete preparation process is:

(1), preparation catalyst precarsor:, make composite oxides with the dissolving of group vib and/or group VIII slaine, dry and calcining at least 4 hours under 673K-823K;

(2), above-mentioned composite oxides are carried out temperature programmed reduction, preparation nitride: in the presence of hydrogen and nitrogen, be warming up to 823K～923K, and under this temperature, reduced at least 2 hours, and at room temperature, passivation is at least 8 hours in the inert gas atmosphere, obtains catalyst of the present invention.

8. according to the described preparation method of claim 7, it is characterized in that wherein the said 823K～923K that is warming up in the step (2) adopts linear mode to heat up or temperature-gradient method.

9. according to the described preparation method of claim 8, it is characterized in that said linear temperature increase is the heating rate intensification with 0.5-3K/min.

10. according to the described preparation method of claim 9, it is characterized in that said temperature-gradient method rises to 523K～723K for first heating rate with 3-4K, the heating rate with 0.5-1K is warming up to 823K～923K again.