CN112742402B

CN112742402B - Hydrodesulfurization catalyst and preparation method thereof

Info

Publication number: CN112742402B
Application number: CN201911044123.4A
Authority: CN
Inventors: 范峰; 凌凤香; 张会成; 王少军; 杨春雁; 金鑫
Original assignee: China Petroleum and Chemical Corp; Sinopec Dalian Research Institute of Petroleum and Petrochemicals
Current assignee: Sinopec Dalian Petrochemical Research Institute Co ltd; China Petroleum and Chemical Corp
Priority date: 2019-10-30
Filing date: 2019-10-30
Publication date: 2022-08-12
Anticipated expiration: 2039-10-30
Also published as: CN112742402A

Abstract

The invention discloses a hydrodesulfurization catalyst and a preparation method thereof, wherein the preparation method comprises the following steps: (1) mixing a compound containing an active metal component with water, uniformly mixing, adding an alumina carrier, and carrying out low-temperature heat treatment; (2) and (2) mixing the material obtained in the step (1), diethylenetriamine and alcohol, uniformly mixing, standing, and finally roasting to obtain the hydrodesulfurization catalyst. The catalyst provided by the invention has the advantages of high active metal dispersion degree, excellent desulfurization performance and simple and feasible preparation method.

Description

Hydrodesulfurization catalyst and preparation method thereof

Technical Field

The invention belongs to the field of oil refining chemical industry, and particularly relates to a catalytic material and a preparation method thereof.

Background

With the increasing strictness of environmental regulations, higher requirements are also put forward on the performance of hydrogenation catalysts, so that the catalysts are required to have more excellent catalytic performance, and the production cost of the catalysts is required to be lower.

CN1508222A discloses a hydrotreating catalyst and a preparation method thereof, wherein the catalyst is prepared by taking pseudo-thin hydrated alumina, a silicon-containing compound and a VIB group metal such as molybdenum or tungsten as raw materials, and preparing an alumina carrier containing molybdenum or tungsten through the steps of full mixing, kneading, extruding and forming, drying, high-temperature roasting and the like. Then impregnating the carrier with an aqueous solution containing a group VIIIB metal such as a nickel or cobalt compound, drying and calcining at high temperature to obtain the hydrotreating catalyst.

CN106622266B discloses a hydrodesulfurization catalyst and a preparation method and application thereof, the catalyst contains an active metal component and a modified hydrogenation catalyst carrier, the metal auxiliary and an acid auxiliary are distributed on the carrier in a layered manner, a first shell layer is the metal auxiliary, a first core layer is the acid auxiliary, the metal auxiliary is a group IA metal component and/or a group IIA metal component, and the acid auxiliary is at least one component selected from F, P and B. The technology is mainly used in the heavy oil hydrogenation treatment, and can obtain better desulfurization, carbon residue removal effect, denitrification effect and asphaltene removal effect.

CN106660017B discloses a medium-pore and large-pore catalyst for hydroconversion of residual oil and a preparation method thereof. The catalyst of the invention comprises: a support and an active metal phase of alumina comprising at least one metal of group VIB of the periodic table, optionally at least one metal of group VIII. The preparation method of the catalyst comprises the following steps: dissolution of the acidic aluminum precursor; adjusting the pH by an alkaline precursor; co-precipitation of an acidic precursor and a basic precursor, at least one of the two precursors comprising aluminum, to form a suspension of an alumina gel having a target alumina concentration; filtering; drying to obtain a powder; molding; heat treating to obtain an alumina support; impregnation of the hydrogenation-dehydrogenation active phase on said alumina support. The catalyst of the invention is mainly used for hydrotreating or hydro-converting heavy hydrocarbon raw materials.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a hydrodesulfurization catalyst and a preparation method thereof. The preparation method of the invention can improve the effective utilization rate of the active metal in the catalyst, reduce the preparation cost of the catalyst and solve the problems that the catalytic performance is influenced and the preparation cost of the catalyst is higher because the active metal of the catalyst is not uniformly dispersed in the existing preparation method.

In a first aspect, the present invention provides a method for preparing a hydrodesulfurization catalyst, the method comprising:

(1) mixing the compound containing active metal component with water, adding alumina carrier after mixing uniformly and carrying out low-temperature heat treatment

(2) And (2) mixing the material obtained in the step (1), diethylenetriamine and alcohol, uniformly mixing, standing, and finally roasting to obtain the hydrodesulfurization catalyst.

In the preparation method of the hydrodesulfurization catalyst, the alumina in the step (1) is preferably pretreated at 150-300 ℃, preferably 160-280 ℃, for 1-6 h, preferably 2-5 h.

In the preparation method of the hydrodesulfurization catalyst, in the step (1), the active metal component is one or more of group VIB metals and/or group VIII metals, wherein the group VIB metals may be Mo and/or W, the group VIII metals may be Co and/or Ni, further preferably Mo and/or Co, and still further preferably Mo and Co. When the active metal component is Mo, the molybdenum-containing compound can be one or more of ammonium heptamolybdate, ammonium dimolybdate, ammonium tetramolybdate, ammonium octamolybdate and molybdenum nitrate; when the active metal component is Co, the cobalt-containing compound may be one or more of cobalt nitrate, cobalt sulfate, cobalt carbonate and basic cobalt carbonate.

In the preparation method of the hydrodesulfurization catalyst, the amount of the active metal component in the active metal component compound in the step (1) can be selected according to requirements. When the active metal components are Mo and Co, the mass ratio (in oxide form) of the molybdenum compound, the cobalt compound and the alumina is 5-31 MoO ₃ ：0.8～7 Co ₂ O ₃ ：100 H ₂ O, preferably 6 to 30 MoO ₃ ：1～6 Co ₂ O ₃ ：100 H ₂ O。

In the preparation method of the hydrodesulfurization catalyst, the mixing in the step (1) adopts an impregnation method, preferably an isometric saturation impregnation method, and the dosage of water is determined by the isometric saturation impregnation method.

In the preparation method of the hydrodesulfurization catalyst, the operation conditions of the low-temperature heat treatment in the step (1) are as follows: the treatment temperature is 100-200 ℃, and preferably 110-180 ℃; the treatment time is 1-6 h, preferably 2-5 h.

In the preparation method of the hydrodesulfurization catalyst, the mass ratio of the diethylenetriamine to the oxide containing the active metal component in the step (2) is 0.09-0.4: 1, preferably 0.1 to 0.35: 1.

in the preparation method of the hydrodesulfurization catalyst, the alcohol in the step (2) is one or more of ethanol, propanol and butanol, and the dosage of the alcohol is determined by an equal volume saturation impregnation method.

In the preparation method of the hydrodesulfurization catalyst, the standing condition in the step (2) is kept for 2-10 hours at 20-60 ℃, and preferably kept for 3-8 hours at 30-50 ℃.

In the preparation method of the hydrodesulfurization catalyst, the roasting temperature in the step (2) is 400-650 ℃, preferably 450-600 ℃; the roasting time is 2-10 h, preferably 3-8 h; the roasting is carried out in the presence of oxygen-containing gas, the oxygen-containing gas can be oxygen, air, mixed gas of oxygen and inert gas, and the flow rate of the oxygen-containing gas is 500-550 mL/min, preferably 100-500 mL/min.

The second aspect of the invention provides a hydrodesulfurization catalyst obtained by the preparation method.

The catalyst of the invention can be used as a hydrodesulfurization catalyst and can be used for removing sulfur compounds in oil products. The hydrodesulfurization catalyst of the invention needs to be sulfurized before use. The vulcanization may be carried out by any of the vulcanization methods known in the art.

Compared with the prior art, the hydrodesulfurization catalyst and the preparation method thereof provided by the invention have the following advantages:

(1) in the existing catalyst preparation process, active metal in the catalyst can be converted into an oxide form in the high-temperature roasting process and loaded on the surface of alumina, and due to high-temperature roasting, the active metal can move and aggregate on the surface of the alumina and aggregate into aggregates consisting of a plurality of molecules, and if the aggregates are too large, the dispersion degree of the active metal can be reduced, and the utilization rate of the active metal can be reduced. In the preparation method of the hydrodesulfurization catalyst, active metal is loaded on an alumina carrier at low temperature, and then highly uniform dispersion of the active metal on the alumina is realized under the action of diethylenetriamine and alcohol, so that the utilization rate of the active metal is improved. The reason for this may be that the active metal is firstly uniformly adsorbed on the surface of the alumina, and then in the presence of diethylenetriamine, the migration capability of the active metal in the high temperature treatment stage is limited, and finally the formed active metal aggregate is smaller, so that the dispersion degree of the active metal is improved, and the utilization rate of the active metal is improved.

(2) The hydrodesulfurization catalyst prepared by the preparation method disclosed by the invention belongs to a high-dispersion catalyst, and the high-dispersion catalyst has the advantages that the utilization efficiency of active metal in the catalyst can be improved, namely, the use amount of the active metal is reduced under the condition that the catalytic performance of the catalyst is ensured to be unchanged, and the preparation cost of the catalyst is reduced. Solves the problem of high preparation cost of the prior catalyst which is urgently needed to be solved.

Drawings

FIG. 1 is a TEM photograph of a synthesized sample of example 1.

FIG. 2 is a TEM photograph of a synthesized sample of comparative example 1.

Detailed Description

The synthesis of the analcime of the present invention is described in detail below by way of specific examples, but is not limited thereto.

The metal dispersion degree of the hydrodesulfurization catalyst obtained by the preparation method is determined by adopting a transmission electron microscope, and the dispersion degree of the metal on the carrier is directly observed by the electron microscope.

Example 1

100g of alumina was treated at 190 ℃ for 3 h. Then 25.1g of ammonium heptamolybdate, 13.7g of cobalt nitrate and 93g of distilled water (0.93 g of distilled water/1 g of alumina as measured by the equal volume saturation impregnation method) are mixed uniformly; then evenly mixing with alumina, and processing for 3h at 135 ℃. Then mixing with 6.2g of diethylenetriamine and 93g of ethanol (0.93 g of ethanol/1 g of alumina measured by an equal volume saturation impregnation method); keeping at 40 ℃ for 5 h. And finally, treating for 3.5h at 550 ℃ in an air atmosphere with the flow rate of 400mL/min to obtain a catalyst sample, wherein the obtained sample is numbered CL 1. As can be seen from FIG. 1, the dark spots in the TEM photograph are active metals, the spot size is uniform and is 1-1.2 nm, and no large-size metal particles in an agglomerated state are observed, which indicates that the metal dispersion degree of the sample is good.

Example 2

100g of alumina was treated at 160 ℃ for 5 h. Then 7.36g of ammonium heptamolybdate, 23.31g of cobalt nitrate and 93g of distilled water (0.93 g of distilled water/1 g of alumina as measured by the equal volume saturation impregnation method) are mixed uniformly; then evenly mixing with alumina, and processing for 5h at 110 ℃. Then mixed with 1.2g of diethylenetriamine and 93g of ethanol (0.93 g of ethanol/1 g of alumina measured by an equal volume saturation impregnation method); the temperature is kept at 30 ℃ for 8 h. And finally, treating for 8 hours at 450 ℃ in an air atmosphere with the flow rate of 500mL/min to obtain a catalyst sample, wherein the obtained sample is numbered CL 2.

Example 3

100g of alumina was treated at 280 ℃ for 2 h. 36.78g of ammonium heptamolybdate, 3.88g of cobalt nitrate and 93g of distilled water (0.93 g of distilled water/1 g of alumina measured by an equal volume saturation impregnation method) are mixed uniformly; then evenly mixing with alumina, and processing for 2h at 180 ℃. And then mixed with 12.6g of diethylenetriamine and 93g of ethanol (0.93 g of ethanol/1 g of alumina measured by an equal volume saturation impregnation method); the temperature is kept at 50 ℃ for 3 h. And finally, treating for 3 hours at 600 ℃ in an air atmosphere with the flow rate of 100mL/min to obtain a catalyst sample, wherein the obtained sample is numbered CL 3.

Example 4

100g of alumina was treated at 240 ℃ for 3 h. Then 16.7g of molybdenum nitrate, 5.8g of cobalt sulfate and 93g of distilled water (0.93 g of distilled water/1 g of alumina measured by an equal volume saturation impregnation method) are mixed uniformly; then evenly mixing with alumina, and processing for 4h at 170 ℃. And then mixed with 6.5g of diethylenetriamine and 93g of propanol (0.93 g of propanol/1 g of alumina measured by the equal volume saturation impregnation method); the temperature is kept at 45 ℃ for 7 h. Finally, treating for 4 hours at 550 ℃ in an air atmosphere with the flow rate of 300mL/min to obtain a catalyst sample, wherein the obtained sample is numbered CL4

Example 5

100g of alumina was treated at 185 ℃ for 3.5 h. Then, 15.6g of molybdenum nitrate, 9.3g of cobalt sulfate and 93g of distilled water (0.93 g of distilled water/1 g of alumina measured by an equal volume saturation impregnation method) are mixed uniformly; then evenly mixing with alumina, and processing for 2.5h at 125 ℃. Mixing with 8.3g of diethylenetriamine and 93g of butanol (0.93 g of butanol/1 g of alumina measured by an equal volume saturation impregnation method); keeping at 40 ℃ for 5 h. And finally, treating for 5 hours at 500 ℃ in an air atmosphere with the flow rate of 200mL/min to obtain a catalyst sample, wherein the obtained sample is numbered CL 5.

Evaluation test:

Example 6

The catalyst samples obtained in example 1 were respectively tableted, molded and crushed, and 10mL of 20-60 mesh catalyst was selected and loaded into a microreactor. Then 15mL/h of n-octane containing 5% (weight ratio) of carbon disulfide is introduced, 160mL/min of hydrogen is introduced, the system pressure is maintained at 3MPa, the system temperature is 320 ℃, the treatment time is 4h, and the catalyst is vulcanized. Then 15mL/h of n-nonane containing 300ppm (weight ratio) of thiophene is introduced, 160mL/min of hydrogen is introduced, the system pressure is maintained at 3.1MPa, the system temperature is 300 ℃, and the liquid products with the reaction time from 3h to 4h are taken for sulfur content analysis. The sulfur content of the liquid product after hydrodesulfurization was determined to be 7ppm by weight.

Example 7

The catalyst sample obtained in example 1 was replaced with the catalyst sample obtained in example 2, and the sulfur content of the liquid product after hydrodesulfurization was measured to be 8pm (weight ratio) in comparison with example 6.

Example 8

In comparison with example 6, except that the catalyst sample obtained in example 1 was replaced with the catalyst sample obtained in example 3, the sulfur content of the liquid product after hydrodesulfurization was measured to be 8ppm (by weight).

Example 9

In comparison with example 6, except that the catalyst sample obtained in example 1 was replaced with the catalyst sample obtained in example 4, the sulfur content of the liquid product after hydrodesulfurization was measured to be 10ppm by weight.

Example 10

In comparison with example 6, except that the catalyst sample obtained in example 1 was replaced with the catalyst sample obtained in example 5, the sulfur content of the liquid product after hydrodesulfurization was measured to be 7ppm (by weight).

Comparative example 1

According to the conventional method, firstly, 25.1g of ammonium heptamolybdate, 13.7g of cobalt nitrate and 93g of distilled water (0.93 g of water/1 g of alumina measured by an isometric saturation impregnation method) are uniformly mixed; then 100g of alumina is taken to be treated for 3h at 135 ℃, is evenly mixed with the solution obtained in the previous step, and is kept for 4h at 45 ℃; and finally, treating for 3.5 hours at 550 ℃ in an air atmosphere with the flow rate of 400mL/min to obtain a catalyst sample, wherein the obtained sample is CL 6. As can be seen from fig. 2, the dark spots in the TEM photograph are active metals, the spot sizes are very uneven, one is active metal with a size less than 1.2nm, and such active metal belongs to a well-dispersed metal; the other is active metal with the size larger than 5nm, and the active metal is subjected to metal agglomeration and belongs to metal with poor dispersion. In general, the active metal of the catalyst prepared by the method has serious metal agglomeration phenomenon, the metal dispersion degree is poor, and the preparation method has poor effect.

Comparative example 2

The catalyst obtained in comparative example 1 is tableted, molded, pulverized, and then 10mL of 20-60 mesh catalyst is selected and loaded into a microreactor. Then 15mL/h of n-octane containing 5% (weight ratio) of carbon disulfide is introduced, 160mL/min of hydrogen is introduced, the system pressure is maintained at 3MPa, the system temperature is 320 ℃, the treatment time is 4h, and the catalyst is vulcanized. Then 15mL/h of n-nonane containing 300ppm (weight ratio) of thiophene is introduced, 160mL/min of hydrogen is introduced, the system pressure is maintained at 3.1MPa, the system temperature is 300 ℃, and the liquid products with the reaction time from 3h to 4h are taken for sulfur content analysis. The sulfur content of the liquid product after hydrodesulfurization was measured to be 70ppm by weight, and the desulfurization rate was much lower than that of example 6 (the catalyst metal content and the reaction conditions were the same). The catalytic performance of the catalyst prepared by the method is more excellent.

TABLE 1 Electron microscopy of samples obtained in examples and comparative examples

Sample name	State of metal dispersion
		CL1	No agglomeration phenomenon
CL2	No agglomeration phenomenon
		CL3	No agglomeration phenomenon
CL4	No agglomeration phenomenon
		CL6	Agglomeration phenomenon occurs

Claims

1. A preparation method of a hydrodesulfurization catalyst comprises the following steps:

(1) Mixing a compound containing an active metal component with water, uniformly mixing, adding an alumina carrier, and performing low-temperature heat treatment at the temperature of 100-200 ℃;

(2) mixing the material obtained in the step (1), diethylenetriamine and alcohol, uniformly mixing, standing, and finally roasting to obtain a hydrodesulfurization catalyst; the alcohol is one or more of ethanol, propanol and butanol.

2. The process for producing a hydrodesulfurization catalyst according to claim 1, wherein: and (2) pretreating the alumina in the step (1), wherein the pretreatment is to treat the alumina at 150-300 ℃ for 1-6 h.

3. A process for preparing a hydrodesulfurization catalyst according to claim 1 or 2, comprising: and (2) pretreating the alumina in the step (1), wherein the pretreatment is to treat the alumina at 160-280 ℃ for 2-5 h.

4. The process for producing a hydrodesulfurization catalyst according to claim 1, wherein: in the step (1), the active metal component is one or more of VIB group metals and/or VIII group metals, wherein the VIB group metals are Mo and/or W, and the VIII group metals are Co and/or Ni.

5. A process for preparing a hydrodesulfurization catalyst according to claim 1 or 4, wherein: in the step (1), the active metal component is Mo and/or Co.

6. A process for preparing a hydrodesulfurization catalyst according to claim 1 or 4, wherein: the active metal components in the step (1) are Mo and Co.

7. The process for producing a hydrodesulfurization catalyst according to claim 1, wherein: the operating conditions of the low-temperature heat treatment in the step (1) are as follows: the treatment temperature is 110-180 ℃.

8. The process for producing a hydrodesulfurization catalyst according to claim 1, wherein: the operating conditions of the low-temperature heat treatment in the step (1) are as follows: the treatment time is 1-6 h.

9. A process for preparing a hydrodesulfurization catalyst according to claim 1 or 8, comprising: the operating conditions of the low-temperature heat treatment in the step (1) are as follows: the treatment time is 2-5 h.

10. The process for producing a hydrodesulfurization catalyst according to claim 1, wherein: in the step (2), the standing condition is kept for 2-10 hours at the temperature of 20-60 ℃.

11. A process for preparing a hydrodesulfurization catalyst according to claim 1 or 10, comprising: and (3) keeping the standing condition in the step (2) for 3-8 hours at the temperature of 30-50 ℃.

12. The process for producing a hydrodesulfurization catalyst according to claim 1, wherein: in the step (2), the roasting temperature is 400-650 ℃, the roasting time is 2-10 h, and the roasting is carried out in the presence of oxygen-containing gas.

13. A process for preparing a hydrodesulfurization catalyst according to claim 1 or 12, comprising: in the step (2), the roasting temperature is 450-600 ℃; the roasting time is 3-8 h; the calcination is carried out in the presence of an oxygen-containing gas.

14. The process for producing a hydrodesulfurization catalyst as set forth in claim 13, wherein: the oxygen-containing gas is a mixed gas of oxygen, air, oxygen and inert gas, and the flow rate of the oxygen-containing gas is 100-500 mL/min.

15. A hydrodesulfurization catalyst obtained by the production method according to any one of claims 1 to 14.