阅读说明：本技术 一种含硫废气处理用加氢催化剂及其应用 (Hydrogenation catalyst for treating sulfur-containing waste gas and application thereof ) 是由 程鹏 周典 曹雨 于 2020-12-28 设计创作，主要内容包括：本发明中,本发明提出了一种含硫废气处理用加氢催化剂及其应用,所述催化剂是通过下述方法制备得到：将分子筛进行铵离子交换,得到氨型分子筛；将加氢活性金属组分采用浸渍法负载到氨型分子筛上,得到催化剂前体；再在催化剂前体表面包覆氧化铝,即得到所述催化剂。本发明所述催化剂具有脱硫催化活性及选择性好,稳定性高的优点。(The invention provides a hydrogenation catalyst for treating sulfur-containing waste gas and application thereof, wherein the catalyst is prepared by the following method: carrying out ammonium ion exchange on the molecular sieve to obtain an ammonia type molecular sieve; loading a hydrogenation active metal component on an ammonia molecular sieve by adopting an impregnation method to obtain a catalyst precursor; and coating alumina on the surface of the catalyst precursor to obtain the catalyst. The catalyst has the advantages of good desulfurization catalytic activity and selectivity and high stability.)

1. A hydrogenation catalyst for treating sulfur-containing waste gas, which is characterized by being prepared by the following method: carrying out ammonium ion exchange on the molecular sieve to obtain an ammonia type molecular sieve; loading a hydrogenation active metal component on an ammonia molecular sieve by adopting an impregnation method to obtain a catalyst precursor; and coating alumina on the surface of the catalyst precursor to obtain the catalyst.

2. The hydrogenation catalyst for sulfur-containing off-gas treatment according to claim 1, wherein the molecular sieve is at least one of a Y-type molecular sieve, a ZSM-series molecular sieve, or an MCM-series molecular sieve; preferably, the molecular sieve is a Y-type molecular sieve.

3. The sulfur-containing exhaust gas treatment hydrogenation catalyst according to claim 1 or 2, wherein the hydrogenation-active metal component comprises a group VIII metal and a group VIB metal; preferably, the content of the hydrogenation active metal component in the hydrogenation catalyst is 1 to 30 wt% calculated on oxide basis.

4. The sulfur-containing exhaust gas treatment hydrogenation catalyst according to any one of claims 1 to 3, wherein the "subjecting the molecular sieve to ammonium ion exchange" specifically comprises: adding the molecular sieve into an ammonium salt water solution, stirring for reaction, filtering, washing with water, and drying to obtain the ammonia type molecular sieve; preferably, the temperature of the stirring reaction is 60-100 ℃ and the time is 1-3 h.

5. The hydrogenation catalyst for sulfur-containing off-gas treatment according to claim 4, wherein said ammonium salt is ammonium chloride and/or ammonium nitrate.

6. The hydrogenation catalyst for sulfur-containing exhaust gas treatment according to any one of claims 1 to 5, wherein the "loading the hydrogenation active metal component onto the ammonia-type molecular sieve by an impregnation method" specifically comprises: preparing a metal salt corresponding to the hydrogenation active metal component into a solution, then soaking the solution in an ammonia molecular sieve, and then aging, drying and roasting to obtain the catalyst precursor; preferably, the drying temperature is 60-120 ℃, the drying time is 6-12h, the roasting temperature is 400-600 ℃, and the roasting time is 4-10 h.

7. The sulfur-containing exhaust gas treatment hydrogenation catalyst according to any one of claims 1 to 6, wherein the "coating of the surface of the catalyst precursor with alumina" specifically comprises: adding the catalyst precursor into an organic solvent, adding aluminum isopropoxide and ammonia water, stirring for reaction, filtering, drying and roasting to obtain the catalyst; preferably, the drying temperature is 80-180 ℃ and the time is 2-6h, the roasting temperature is 300-500 ℃ and the time is 1-3 h.

8. The sulfur-containing exhaust gas treatment hydrogenation catalyst according to claim 7, wherein the amount of the aluminum isopropoxide is 5 to 30 wt% of the molecular sieve.

9. Use of a catalyst according to any one of claims 1 to 8 in the treatment of sulfur-containing exhaust gases.

Technical Field

The invention relates to the technical field of catalysts, and particularly relates to a hydrogenation catalyst for treating sulfur-containing waste gas and application thereof.

Background

The coke oven gas, the natural gas, the petroleum associated gas, the refinery waste gas and other gases contain a large amount of organic sulfur compounds including carbonyl sulfur, thioether, mercaptan, thiophene and the like, the organic sulfur compounds have toxicity, and can cause harm to the environment and human bodies along with the emission of the gases, and when the gases are continuously used for industrial production, the organic sulfur compounds can cause the inactivation of catalysts used in industrial reactions, and influence the catalytic performance of the catalysts, so that the industrial yield is reduced, for example, when the coke oven gas is used for preparing methanol, the general methanol synthesis catalysts require that the total sulfur content of the coke oven gas is lower than 0.1ppm, and even more advanced methanol synthesis catalysts require that the total sulfur content of the coke oven gas is lower than 0.05ppm, otherwise, the catalysts are inactivated due to poisoning in the coke oven gas with over-standard sulfur content, so that the gases are subjected to desulfurization treatment before being used for industrial production, including the removal of organic sulfur.

Common methods for removing organic sulfur include oxidation, hydroconversion, and hydroconversion, with hydroconversion being the most common. However, the hydrogenation catalyst used in the current industrial device generally has the defects of insufficient hydrogenation activity and desulfurization activity, higher production cost of the catalyst and the like, and the economic benefit is influenced.

Disclosure of Invention

Based on the technical problems in the background art, the invention provides a hydrogenation catalyst for treating sulfur-containing waste gas and application thereof.

The invention provides a hydrogenation catalyst for treating sulfur-containing waste gas, which is prepared by the following method: carrying out ammonium ion exchange on the molecular sieve to obtain an ammonia type molecular sieve; loading a hydrogenation active metal component on an ammonia molecular sieve by adopting an impregnation method to obtain a catalyst precursor; and coating alumina on the surface of the catalyst precursor to obtain the catalyst.

Preferably, the molecular sieve is at least one of a Y-type molecular sieve, a ZSM series molecular sieve or an MCM series molecular sieve; preferably, the molecular sieve is a Y-type molecular sieve.

Preferably, the hydrogenation active metal component comprises a group VIII metal and a group VIB metal; preferably, the content of the hydrogenation active metal component in the hydrogenation catalyst is 1 to 30 wt% calculated on oxide basis.

Preferably, said "subjecting the molecular sieve to ammonium ion exchange" specifically comprises: adding the molecular sieve into an ammonium salt water solution, stirring for reaction, filtering, washing with water, and drying to obtain the ammonia type molecular sieve; preferably, the temperature of the stirring reaction is 60-100 ℃ and the time is 1-3 h.

Preferably, the ammonium salt is ammonium chloride and/or ammonium nitrate.

Preferably, the "loading the hydrogenation active metal component on the ammonia type molecular sieve by using an impregnation method" specifically comprises the following steps: preparing a metal salt corresponding to the hydrogenation active metal component into a solution, then soaking the solution in an ammonia molecular sieve, and then aging, drying and roasting to obtain the catalyst precursor;

preferably, the drying temperature is 60-120 ℃, the drying time is 6-12h, the roasting temperature is 400-600 ℃, and the roasting time is 4-10 h.

Preferably, the "coating of the surface of the catalyst precursor with alumina" specifically includes: adding the catalyst precursor into an organic solvent, adding aluminum isopropoxide and ammonia water, stirring for reaction, filtering, drying and roasting to obtain the catalyst; preferably, the drying temperature is 80-180 ℃ and the time is 2-6h, the roasting temperature is 300-500 ℃ and the time is 1-3 h.

Preferably, the aluminum isopropoxide is used in an amount of 5 to 30 wt% of the molecular sieve.

The invention also provides an application of the catalyst in sulfur-containing waste gas treatment.

According to the catalyst, the molecular sieve is subjected to ion exchange with ammonium salt in advance, so that in subsequent active metal salt impregnation, the directional exchange of metal ions on ion exchange positions is ensured, the uniform distribution of active metal is facilitated, and the utilization of the active metal is improved; then the molecular sieve loaded with active metal is added into aluminum isopropoxide as a catalyst precursor, a layer of very thin alumina covering material can be deposited on the surface of the molecular sieve, the pore channel property of the molecular sieve is improved, the alumina and the molecular sieve fully play a synergistic role, and the activation efficiency of the catalyst is further ensured to be improved.

Detailed Description

Hereinafter, the technical solution of the present invention will be described in detail by specific examples, but these examples should be explicitly proposed for illustration, but should not be construed as limiting the scope of the present invention.

Example 1

A hydrogenation catalyst for treating sulfur-containing waste gas, which is prepared by the following steps:

s1, mixing 5gY type molecular Sieve (SiO)₂/Al₂O₃The mol ratio is 15, the unit cell parameter is 2.45nm, the crystallization retention is more than 95 percent) is added into 100mL ammonium nitrate solution (10 weight percent), stirred for 2h at 100 ℃, filtered, washed by deionized water and dried for 16h at 120 ℃ to obtain the ammonia type molecular sieve;

s2, adding the ammonia type molecular sieve into a mixed solution of cobalt nitrate and ammonium molybdate (specifically, 0.4716g of cobalt nitrate hexahydrate and 0.7874g of ammonium heptamolybdate tetrahydrate are dissolved in 10mL of deionized water), stirring uniformly, performing ultrasonic treatment for 0.5h, soaking at room temperature for 5h, drying at 100 ℃ for 8h, then placing in a muffle furnace, and roasting at 500 ℃ for 6h to obtain a catalyst precursor;

s3, adding the catalyst precursor into 100mL of ethanol, then adding 1g of aluminum isopropoxide, stirring at room temperature for 1h, then dropwise adding 0.2mL of ammonia water (0.15mol/L), stirring at room temperature for reaction for 4h, filtering, drying at 150 ℃ for 3h, then placing into a muffle furnace, and roasting at 400 ℃ for 2h to obtain the catalyst.

Example 2

A hydrogenation catalyst for treating sulfur-containing waste gas, which is prepared by the following steps:

s1, mixing 5gY type molecular Sieve (SiO)₂/Al₂O₃The mol ratio is 15, the unit cell parameter is 2.45nm, the crystallization retention is more than 95 percent) is added into 100mL ammonium nitrate solution (10 weight percent), stirred for 2h at 100 ℃, filtered, washed by deionized water and dried for 16h at 120 ℃ to obtain the ammonia type molecular sieve;

s2, adding the ammonia type molecular sieve into a mixed solution of nickel nitrate and ammonium molybdate (specifically, 0.4738g of nickel nitrate hexahydrate and 0.7874g of ammonium heptamolybdate tetrahydrate are dissolved in 10mL of deionized water), stirring uniformly, then carrying out ultrasonic treatment for 0.5h, dipping for 5h at room temperature, then drying for 8h at 100 ℃, then placing into a muffle furnace, and roasting for 6h at 500 ℃ to obtain a catalyst precursor;

s3, adding the catalyst precursor into 100mL of ethanol, then adding 1g of aluminum isopropoxide, stirring at room temperature for 1h, then dropwise adding 0.2mL of ammonia water (0.15mol/L), stirring at room temperature for reaction for 4h, filtering, drying at 150 ℃ for 3h, then placing into a muffle furnace, and roasting at 400 ℃ for 2h to obtain the catalyst.

Example 3

A hydrogenation catalyst for treating sulfur-containing waste gas, which is prepared by the following steps:

s1, mixing 5gY type molecular Sieve (SiO)₂/Al₂O₃The mol ratio is 15, the unit cell parameter is 2.45nm, the crystallization retention is more than 95 percent) is added into 100mL ammonium nitrate solution (10 weight percent), stirred for 2h at 100 ℃, filtered, washed by deionized water and dried for 16h at 120 ℃ to obtain the ammonia type molecular sieve;

s2, adding the ammonia type molecular sieve into a mixed solution of nickel nitrate and ammonium metatungstate (specifically, 0.4738g of nickel nitrate hexahydrate and 1.1596g of ammonium metatungstate hexahydrate are dissolved in 10mL of deionized water), stirring uniformly, performing ultrasonic treatment for 0.5h, soaking at room temperature for 5h, drying at 100 ℃ for 8h, placing in a muffle furnace, and roasting at 500 ℃ for 6h to obtain a catalyst precursor;

s3, adding the catalyst precursor into 100mL of ethanol, then adding 1g of aluminum isopropoxide, stirring at room temperature for 1h, then dropwise adding 0.2mL of ammonia water (0.15mol/L), stirring at room temperature for reaction for 4h, filtering, drying at 150 ℃ for 3h, then placing into a muffle furnace, and roasting at 400 ℃ for 2h to obtain the catalyst.

Example 4

A hydrogenation catalyst for treating sulfur-containing waste gas, which is prepared by the following steps:

s1, drying 5g of ZSM-5 molecular sieve raw powder at 500 ℃ for 5h, adding the dried powder into 100mL of ammonium nitrate solution (10 wt%), stirring the solution for 2h at 100 ℃, filtering the solution, washing the solution with deionized water, and drying the solution for 16h at 120 ℃ to obtain the ammonia type molecular sieve;

s2, adding the ammonia type molecular sieve into a mixed solution of cobalt nitrate and ammonium molybdate (specifically, 0.4716g of cobalt nitrate hexahydrate and 0.7874g of ammonium heptamolybdate tetrahydrate are dissolved in 10mL of deionized water), stirring uniformly, performing ultrasonic treatment for 0.5h, soaking at room temperature for 5h, drying at 100 ℃ for 8h, then placing in a muffle furnace, and roasting at 500 ℃ for 6h to obtain a catalyst precursor;

s3, adding the catalyst precursor into 100mL of ethanol, then adding 1g of aluminum isopropoxide, stirring at room temperature for 1h, then dropwise adding 0.2mL of ammonia water (0.15mol/L), stirring at room temperature for reaction for 4h, filtering, drying at 150 ℃ for 3h, then placing into a muffle furnace, and roasting at 400 ℃ for 2h to obtain the catalyst.

Comparative example 1

A hydrogenation catalyst, the preparation method of which comprises:

mixing 5gY type molecular Sieve (SiO)₂/Al₂O₃The method comprises the following steps of adding the cobalt nitrate and ammonium molybdate mixed solution (specifically, 0.4716g of cobalt nitrate hexahydrate and 0.7874g of ammonium heptamolybdate tetrahydrate are dissolved in 10mL of deionized water) into a solution with a molar ratio of 15, unit cell parameters of 2.45nm and a crystallization retention degree of more than 95%), stirring uniformly, performing ultrasonic treatment for 0.5h, soaking at room temperature for 5h, drying at 100 ℃ for 8h, placing in a muffle furnace, and roasting at 500 ℃ for 6h to obtain the hydrogenation catalyst.

Comparative example 2

A hydrogenation catalyst, the preparation method of which comprises:

s1, mixing 5gY type molecular Sieve (SiO)₂/Al₂O₃The mol ratio is 15, the unit cell parameter is 2.45nm, the crystallization retention is more than 95 percent) is added into 100mL ammonium nitrate solution (10 weight percent), stirred for 2h at 100 ℃, filtered, washed by deionized water and dried for 16h at 120 ℃ to obtain the ammonia type molecular sieve;

s2, adding the ammonia type molecular sieve into a mixed solution of cobalt nitrate and ammonium molybdate (specifically, 0.4716g of cobalt nitrate hexahydrate and 0.7874g of ammonium heptamolybdate tetrahydrate are dissolved in 10mL of deionized water), stirring uniformly, performing ultrasonic treatment for 0.5h, soaking at room temperature for 5h, drying at 100 ℃ for 8h, then placing in a muffle furnace, and roasting at 500 ℃ for 6h to obtain the hydrogenation catalyst.

The catalysts of examples 1 to 4 and comparative examples 1 to 2 were evaluated. Sulfur-containing exhaust gas for evaluation to include N₂、SO₂、CS₂、O₂、H₂Etc. of sulfur-containing waste gas, the properties of which are shown in Table 1 belowThe evaluation method is as follows: crushing the catalyst, sieving the crushed catalyst by a 20-40-mesh sieve, and then placing the sieved particles in a 10mL fixed bed catalytic reaction device for presulfurization, wherein the presulfurization conditions are as follows: hydrogen gas mixture containing 2% (volume fraction) of hydrogen sulfide is adopted for presulfurization, the reaction pressure is normal pressure, the reaction temperature is 300 ℃, and the volume space velocity is 1250h^-1(ii) a Then switching to sulfur-containing waste gas for reaction, wherein the reaction conditions are as follows: the reaction pressure is normal pressure, the reaction temperature is 220 ℃, and the volume space velocity is 1250h^-1Starting from the feeding of the hydrogenation reaction, sampling and analyzing after the reaction is stable. The reaction results are shown in table 2 below.

TABLE 1 Properties of Sulfur-containing waste gas

Table 2 evaluation of hydrogenation catalyst effect on sulfur-containing exhaust gas by hydrogenation catalyst as described in examples and comparative examples

	SO2Hydroconversion rate,% of	CS2A rate of hydrolysis%	O2Hydroconversion rate,% of
				Example 1	99.2	98.5	99.9
Example 2	95.4	92.3	98.3
				Example 3	92.6	91.7	97.9
Example 4	97.1	95.4	99.8
				Comparative example 1	76.2	62.9	54.5
Comparative example 2	88.6	81.2	76.1

As can be seen from Table 2, the catalyst prepared by the method of the present invention has a better desulfurization and denitrification capability for sulfur-containing exhaust gas.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.