阅读说明：本技术 基于煤液化油渣萃余物的加氢脱硫催化剂及其制备方法 (Hydrodesulfurization catalyst based on coal liquefaction oil residue raffinate and preparation method thereof ) 是由 廖俊杰 刘洋 王建成 闫伦靖 常丽萍 鲍卫仁 于 2020-08-06 设计创作，主要内容包括：本发明公开了一种基于煤液化油渣萃余物的加氢脱硫催化剂及其制备方法,是以四氢呋喃可溶物含量低于3wt%,硫含量不小于1wt%,铁含量不小于2wt%的煤液化油渣萃余物为原料,经空气氧化后,以钼酸盐水溶液充分浸渍,惰性气氛下高温焙烧后制备得到的加氢脱硫催化剂,本发明的加氢脱硫催化剂无需硫化处理,可直接用于焦炉煤气的干法脱硫工艺中,具有优异的有机硫加氢催化活性。(The invention discloses a hydrodesulfurization catalyst based on coal liquefaction oil residue raffinate and a preparation method thereof, wherein the hydrodesulfurization catalyst is prepared by taking the coal liquefaction oil residue raffinate with tetrahydrofuran soluble content lower than 3wt%, sulfur content not less than 1wt% and iron content not less than 2wt% as a raw material, fully soaking in a molybdate aqueous solution after air oxidation, and roasting at high temperature under an inert atmosphere.)

1. A hydrodesulfurization catalyst based on coal liquefaction oil residue raffinate is a hydrodesulfurization catalyst prepared by using coal liquefaction oil residue raffinate with tetrahydrofuran soluble content of less than 3wt%, sulfur content of not less than 1wt% and iron content of not less than 2wt% as a raw material, fully soaking the raw material in a molybdate aqueous solution after air oxidation, and roasting the raw material at high temperature in an inert atmosphere.

2. The hydrodesulfurization catalyst according to claim 1, wherein the mass ratio of molybdenum to iron in the hydrodesulfurization catalyst is 1: 0.5 to 3, calculated as the element.

3. The hydrodesulfurization catalyst according to claim 2, wherein the mass ratio of molybdenum to iron is 1: 1 to 2, calculated as the element.

4. A method of preparing the hydrodesulfurization catalyst of claim 1 comprising:

1) selecting coal liquefaction oil residue raffinate with tetrahydrofuran soluble content lower than 3wt%, sulfur content not less than 1wt% and iron content not less than 2wt%, drying, crushing, and taking fine powder of 40-80 meshes;

2) oxidizing the fine coal liquefaction oil residue extraction residue powder in an air atmosphere;

3) dissolving molybdate in deionized water to prepare molybdate aqueous solution;

4) adding the oxidized coal liquefaction oil residue extract fine powder into a molybdate water solution according to the mass ratio of molybdenum to iron of 1 to (0.5-3) in terms of elements, fully soaking and standing;

5) and drying the mixture obtained after impregnation, and roasting at high temperature in an inert atmosphere to prepare the hydrodesulfurization catalyst.

5. The preparation method of the hydrodesulfurization catalyst according to claim 4, wherein the raffinate of the coal liquefaction oil residue is dried at 80-120 ℃ for 4-12 hours.

6. The method for preparing a hydrodesulfurization catalyst according to claim 4, wherein the fine coal liquefaction oil residue raffinate powder is oxidized in an air atmosphere at 230 to 280 ℃ for 0.5 to 2 hours.

7. The preparation method of the hydrodesulfurization catalyst according to claim 4, wherein the fine coal liquefaction oil residue raffinate powder is added into the aqueous molybdate solution to be impregnated according to the mass ratio of the volume of the aqueous molybdate solution to the coal liquefaction oil residue raffinate of 0.5-1.3 mL/g.

8. The method for preparing a hydrodesulfurization catalyst according to claim 5, wherein the mixture obtained after impregnation is dried at 100 to 120 ℃ for 4 to 10 hours.

9. The method for preparing a hydrodesulfurization catalyst according to claim 5, wherein the high-temperature calcination is performed at 350 to 600 ℃ for 1 to 6 hours.

10. The use of the hydrodesulfurization catalyst based on coal liquefaction oil residue raffinate of claim 1 as a medium and low temperature coke oven gas organic sulfur hydrogenation catalyst.

Technical Field

The invention relates to a hydrodesulfurization catalyst, in particular to a hydrodesulfurization catalyst prepared by taking raffinate of coal liquefaction oil residue as a raw material. The hydrodesulfurization catalyst prepared by the method is used for hydrodesulfurization of coke oven gas.

Background

The coke oven gas is one of coal coking byproducts, mainly comprises methane, hydrogen, carbon monoxide, carbon dioxide and the like, and can be used for synthesizing natural gas, methanol, ammonia and the like. The coke oven gas after wet desulphurization still contains about 20mg/m³H₂S and 250mg/m³The organic sulfur not only corrodes pipeline equipment, but also easily poisons and deactivates the catalyst, and influences the subsequent utilization of the catalyst. Wherein H₂S can be easily removed by metal oxide adsorption and the like, while organic sulfur is difficult to remove and usually needs to be converted into H by hydrogenation₂And (S) then carrying out adsorption removal.

The hydrogenation removal of organic sulfur in coke oven gas usually adopts Mo-based hydrogenation catalyst, and Fe, Co, Ni and the like are used as auxiliary agents to improve hydrogenation activity. The Fe-Mo hydrodesulfurization catalyst is initially made up of Fe₂O₃、MoO₃The metal sulfide is in a form without desulfurization activity, and before the metal sulfide is used, the metal sulfide must be subjected to reduction vulcanization treatment to be converted into metal sulfide with hydrogenation activity. The vulcanization process generally adopts H₂S or CS₂In order to ensure the thorough vulcanization of the catalyst, an excessive amount of vulcanizing agent is required, and sulfur-containing tail gas generated by vulcanization is harmful to the environment. Therefore, if H can be avoided in the preparation of hydrogenation catalysts₂S or CS₂The use of the vulcanizing agent has the positive effects of obviously saving energy, reducing emission and reducing cost.

CN 101797508A discloses a gamma-Al₂O₃The catalyst is a carrier, Fe, Mo and a certain amount of Co are active components, trace rare earth elements and alkali metals are added as auxiliary agents, the hydrodesulfurization rate is more than 90 percent, but CS is required before the catalyst is used₂Or H₂And S, vulcanizing.

CN 108404901A discloses Al₂O₃The catalyst does not need a vulcanization accelerator, can reduce the using amount of a vulcanizing agent, but still needs CS before use₂And H₂The mixed gas carries out sulfur treatment on Mo active componentAnd (6) chemical treatment.

Coal liquefaction technology is one of important ways of coal utilization, and coal liquefaction oil residue is solid residue generated in the coal liquefaction process and has the characteristics of high ash content and high sulfur content. The main utilization ways of the coal liquefaction oil residue include combustion, gasification, hydro-conversion and the like, but the methods cannot reflect the high value-added utilization value of heavy oil and asphalt substances in the coal liquefaction oil residue, and the defects of serious pollution and low utilization rate in the use process are caused by high sulfur content.

The 35 ten thousand ton/year coal liquefaction oil residue extraction project is built by Eldos coal oil production division company of China Shenhua coal liquefaction chemical industry Limited company, high-temperature coal liquefaction oil residue is used as a raw material, coal tar washing oil is used as an extraction solvent, a coal liquefaction asphalt product and coal liquefaction oil residue raffinate are obtained in a solvent extraction mode, and high value-added application of the coal liquefaction oil residue is realized.

The byproduct coal liquefaction oil residue raffinate of the project is mainly used as boiler fuel at present. However, the combustion produces a large amount of sulfur oxides to pollute the environment, and in addition, the high ash property is not favorable for being used as fuel. Therefore, if a method for effectively utilizing the raffinate of the coal liquefaction oil residue can be provided, the method not only has a positive effect on green high-quality utilization of the coal liquefaction oil residue, but also has important significance on the whole coal liquefaction technology.

Disclosure of Invention

The invention aims to provide a hydrodesulfurization catalyst based on coal liquefaction oil residue raffinate and a preparation method thereof, which can utilize the coal liquefaction oil residue raffinate with high value and avoid using H in the preparation of the hydrodesulfurization catalyst₂S or CS₂And the like.

The hydrodesulfurization catalyst based on the coal liquefaction oil residue raffinate is prepared by using the coal liquefaction oil residue raffinate with tetrahydrofuran soluble content lower than 3wt%, sulfur content not less than 1wt% and iron content not less than 2wt% as a raw material, fully soaking the raw material in a molybdate aqueous solution after air oxidation, and roasting the raw material at high temperature in an inert atmosphere.

Preferably, the loading amount of molybdenum in the hydrodesulfurization catalyst is 5-14 wt%.

The raffinate of the coal liquefaction oil residue is residue of coal liquefaction oil residue generated in the coal hydrogenation liquefaction process after solvent extraction. The main components of the organic solvent are inorganic substances, additional liquefaction catalysts and organic matters with small parts of which are insoluble in an extraction solvent.

Common solvents used for extracting coal liquefaction bottoms can include, but are not limited to, benzene, toluene, tetrahydrofuran, distillates derived from coal liquefaction processes, and coal tar distillates and the like.

The mass ratio of molybdenum to iron in the hydrodesulfurization catalyst is 1: 0.5-3 in terms of elements.

Further, the mass ratio of the molybdenum to the iron is preferably 1 to (1-2) in terms of elements.

The method takes the air oxidized high-iron and high-sulfur coal liquefaction oil residue raffinate as the raw material, adds a molybdenum source, and reduces the generation of active hydrogen in the subsequent roasting process by controlling the content of tetrahydrofuran soluble matters in the coal liquefaction oil residue raffinate so as to ensure that the active sulfur generated by decomposing iron sulfide in the coal liquefaction oil residue raffinate directionally reacts with molybdenum to generate molybdenum sulfide. Thus, the hydrodesulfurization catalyst of the present invention does not require further sulfiding, avoiding H₂S or CS₂And (3) the use of a vulcanizing agent.

Further, the invention also provides a preparation method of the hydrodesulfurization catalyst based on the coal liquefaction oil residue raffinate.

1) Selecting coal liquefaction oil residue raffinate with tetrahydrofuran soluble content lower than 3wt%, sulfur content not less than 1wt% and iron content not less than 2wt%, drying, crushing, and taking fine powder of 40-80 meshes.

2) And oxidizing the coal liquefaction oil residue raffinate fine powder in an air atmosphere.

3) And dissolving molybdate in deionized water to prepare molybdate aqueous solution.

4) Adding the oxidized coal liquefaction oil residue extract fine powder into a molybdate water solution according to the mass ratio of molybdenum to iron of 1 to (0.5-3) in terms of elements, fully soaking and standing.

5) And drying the mixture obtained after impregnation, and roasting at high temperature in an inert atmosphere to prepare the hydrodesulfurization catalyst.

Wherein, if the tetrahydrofuran soluble content of the coal liquefaction oil residue raffinate is higher than 3wt%, tetrahydrofuran can be used for extracting the coal liquefaction oil residue raffinate, so that the tetrahydrofuran soluble content of the raffinate is lower than 3%.

Specifically, the coal liquefaction oil residue extraction residues are dried at the temperature of 80-120 ℃. Preferably, the drying time is generally 4-12 h.

Furthermore, the fine powder of the coal liquefaction oil residue raffinate is oxidized in an air atmosphere at 230-280 ℃. Preferably, the oxidation time is generally 0.5-2 h.

Further, the molybdate is any one of ammonium molybdate, sodium molybdate and magnesium molybdate, or a mixture of several of the ammonium molybdate, the sodium molybdate and the magnesium molybdate in any proportion.

Preferably, the method comprises the step of adding the oxidized fine powder of the coal liquefaction oil residue raffinate into the molybdate aqueous solution for impregnation according to the mass ratio of the volume of the molybdate aqueous solution to the coal liquefaction oil residue raffinate of 0.5-1.3 ml/g.

Furthermore, the method comprises the steps of adding the oxidized fine powder of the raffinate of the coal liquefaction oil residue into a molybdate water solution, soaking for a certain time under ultrasonic-assisted treatment, and standing for a certain time at room temperature.

Wherein the ultrasonic auxiliary treatment is ultrasonic treatment with the power of 50-100W for 10-30 min. And standing at room temperature for 30-120 min.

The mixture obtained after dipping is dried at the temperature of 100-120 ℃. Preferably, the drying time is generally 4-10 h.

Furthermore, the dried mixture is placed in a tube furnace and is roasted at high temperature in an inert atmosphere.

Wherein the roasting temperature is 350-600 ℃, and the roasting time is 1-6 h.

Preferably, the method is to heat the mixture to the roasting temperature at the heating rate of 2-6 ℃/min for high-temperature roasting.

More preferably, the roasting temperature is 400-550 ℃, and the roasting time is 2-4 h.

The catalyst prepared by the method can be used as a coke oven gas hydrodesulfurization catalyst and used in a dry desulfurization process of coke oven gas.

More specifically, the catalyst prepared by the method can be used as a medium-low temperature coke oven gas organic sulfur hydrogenation catalyst.

The invention provides a hydrodesulfurization catalyst prepared by using high-iron and high-sulfur coal liquefaction oil residue raffinate after air oxidation as raw materials, adding a molybdenum source and carrying out high-temperature roasting treatment in an inert atmosphere, aiming at the defect that the existing coke oven gas hydrodesulfurization catalyst needs to be pre-vulcanized before use.

In the preparation of the hydrodesulfurization catalyst, the generation of active hydrogen in the subsequent process is reduced by controlling the content of tetrahydrofuran soluble matters in the raffinate of the coal liquefaction oil residue, so that in the roasting process, active sulfur generated by the decomposition of iron sulfide in the raffinate of the coal liquefaction oil residue directionally reacts with molybdenum to generate molybdenum sulfide. When the roasting temperature is lower than 350 ℃, hydrodesulfurization active sites are difficult to generate, and when the roasting temperature is higher than 600 ℃, iron sulfide is excessively decomposed, so that the desulfurization activity of the catalyst is reduced.

The hydrodesulfurization catalyst prepared by the method disclosed by the invention does not need subsequent vulcanization treatment, namely, the hydrodesulfurization catalyst has excellent organic sulfur hydrogenation catalytic activity, reduces the use of vulcanizing agents, saves the cost and is environment-friendly.

The invention solves the problem that the raffinate of the coal liquefaction oil residue is difficult to treat, provides a new way for the grading high-efficiency utilization of the coal liquefaction oil residue, improves the economic benefit of the coal liquefaction technology, and has important practical significance for the low-cost desulfurization and purification of organic sulfur in coke oven gas.

Drawings

Fig. 1 is a COS hydroconversion curve for a simulated coke oven gas for the hydrodesulfurization catalysts prepared in the respective examples and comparative examples.

Detailed Description

The following examples further describe embodiments of the present invention. The following examples are only for illustrating the technical solutions of the present invention more clearly, and do not limit the scope of the present invention. Various changes, modifications, substitutions and alterations to these embodiments will be apparent to those skilled in the art without departing from the principles and spirit of this invention.