阅读说明：本技术 一种煤焦油加氢预处理催化剂及其制备方法 (Coal tar hydrogenation pretreatment catalyst and preparation method thereof ) 是由 吴艳 马博文 李文博 陈贵锋 常秋连 李军芳 李艳芳 熊银伍 于 2020-06-29 设计创作，主要内容包括：本发明公开了一种煤焦油加氢预处理催化剂及其制备方法。所述催化剂的孔容为0.9～1.5mL/g,比表面积200～300m<Sup>2</Sup>/g,最可几孔径为15～30nm,20～30nm以上大孔的孔体积占总孔容的45～70％。以氧化铝为载体,以VIB和VIII金属元素为活性组分,以磷元素为助剂,加氢预处理催化剂中活性组分以金属计的重量含量为0.4％～10％,助剂磷以元素计的重量含量为0.1％～10％。本发明提供的煤焦油加氢预处理催化剂具有大孔容大孔径,扩散性能优异,具有较高的脱金属和氢解沥青质活性。(The invention discloses a coal tar hydrogenation pretreatment catalyst and a preparation method thereof. The pore volume of the catalyst is 0.9-1.5 mL/g, and the specific surface area is 200-300 m 2 The pore volume of macropores with the most probable pore diameter of 15-30 nm accounts for 45-70% of the total pore volume. The aluminum oxide is used as a carrier, VIB and VIII metal elements are used as active components, a phosphorus element is used as an auxiliary agent, the weight content of the active components in the hydrogenation pretreatment catalyst calculated by the metals is 0.4-10%, and the weight content of the auxiliary agent phosphorus calculated by the elements is 0.1-10%. The coal tar hydrogenation pretreatment catalyst provided by the invention has the advantages of large volumeThe pore volume is large, the diffusion performance is excellent, and the activity of demetalization and asphaltene hydrogenolysis is higher.)

1. The catalyst for coal tar hydrogenation pretreatment is characterized in that alumina is used as a carrier, and the pore volume is 0.9-1.5 mL/g; the specific surface area is 200-300 m²(ii)/g; the most probable pore diameter is 15-30 nm; the pore volume of macropores with the diameter of more than 20-30 nm accounts for 45-70% of the total pore volume, wherein the composite pore-expanding agent adopted by the alumina carrier is a boron-containing compound and polyoxyethylene ether.

2. The catalyst according to claim 1, wherein VIB and VIII metal elements are used as active components, the weight content of the active components in the hydrogenation pretreatment catalyst calculated by metals is 0.4-10%, the weight content of phosphorus in the hydrogenation pretreatment catalyst calculated by phosphorus elements is 0.1-10%.

3. A method for preparing the coal tar hydrogenation pretreatment catalyst according to any one of claims 1 to 2, characterized by comprising the steps of:

(1) preparing an aluminum hydrate by adopting a titration method, adding a phosphorus-containing compound under the stirring condition, standing, cooling, washing and drying to obtain a phosphorus-containing pseudo-boehmite M;

(2) mixing the phosphorus-containing pseudo-boehmite M with the composite pore-expanding agent and the extrusion aid, forming, drying and roasting to obtain an alumina carrier;

(3) preparing a metal solution containing molybdenum and/or tungsten and nickel and/or cobalt, and loading the metal on the carrier obtained in the step (2) in a saturated impregnation mode; washing the materials, drying at 50-120 ℃ for 2-4 hours, and then roasting at 400-700 ℃ for 2-6 hours, wherein the catalyst contains active metal accounting for 0.4-10% of the total weight of the catalyst, and the content of phosphorus element accounting for 0.1-10% of the total weight of the catalyst.

4. The preparation method according to claim 3, wherein the phosphorus-containing pseudoboehmite M has a pore volume of 1.1-2.2 mL/g and a specific surface area of 130-500M²The most probable pore diameter is 15-35 nm.

5. The method according to claim 3, wherein the composite pore-expanding agent is a boron-containing compound and polyoxyethylene ether.

6. The preparation method according to claim 3, wherein the polyoxyethylene ether is one or more of alkylphenol polyoxyethylene, castor oil polyoxyethylene, fatty amine polyoxyethylene and fatty acid polyoxyethylene.

7. The preparation method of claim 3, wherein the addition amount of the polyoxyethylene ether is preferably 0.5-3% of the weight of the corresponding alumina in the pseudo-boehmite dry glue powder.

8. The preparation method according to claim 3, wherein the boron-containing compound is preferably one or more of boric acid, boron oxide and borate; the adding amount of the boron-containing compound is preferably 0.5-5% of the weight of corresponding alumina in the pseudo-boehmite dry glue powder in terms of boron.

9. The preparation method according to claim 3, wherein the extrusion aid is sesbania powder or starch, and the addition amount of the extrusion aid is 1-3% of the weight of corresponding alumina in the pseudo-boehmite dry glue powder.

10. The catalyst according to any one of claims 1 to 2, which is used for hydrogenation catalysts such as a hydrogenation protectant for heavy oil processing, a demetallization catalyst and a deasphalted catalyst.

Technical Field

The invention relates to a hydrogenation pretreatment catalyst and a preparation method thereof, in particular to a coal tar hydrogenation pretreatment catalyst with large aperture and large pore volume and a preparation method thereof.

Background

Coal tar is a valuable chemical feedstock obtained during pyrolysis and gasification of coal. With the rapid development of the low-rank coal pyrolysis technology, the yield of medium and low temperature coal tar is greatly improved. The medium-low temperature coal tar contains more alkanes, cyclanes and less polycyclic aromatic hydrocarbons, is suitable for producing clean fuel oil and high value-added chemicals in a hydrogenation mode,

the residual oil belongs to the most difficult-to-process raw materials in petroleum-based heavy oil, contains a large amount of colloid and asphaltene, and the substances in the residual oil have large molecular weight, complex structure and difficult diffusion, so that the catalyst is required to have an excellent pore channel structure. Compared with residual oil, the coal tar contains much more asphaltene than the residual oil, and because the asphaltene has large molecular diameter and contains a large amount of heteroatoms and metals, the coal tar is easy to form coke by polycondensation and generate metal deposition in the hydrogenation process, and the pore channels of the catalyst are blocked to inactivate the catalyst, thereby providing higher requirements for the coal tar hydrogenation catalyst.

The pore structure of the coal tar hydrogenation pretreatment catalyst is an important property of the catalyst. The diameter of asphaltene molecules and metal heteroatom compounds in the coal tar is large, the coal tar hydrogenation belongs to a diffusion control process, the catalyst is required to have a large pore diameter so that heavy component macromolecules can enter a catalyst pore passage to further act with a surface active site of the catalyst, and the large pore volume is required to contain removed metal impurities, so that the pore structure of the catalyst has a great influence on the reaction effect of the catalyst.

CN107303484A discloses a preparation method of a silicon-containing macroporous alumina carrier, which comprises the steps of impregnating pseudo-boehmite with an aqueous solution of polyhydric alcohol and/or saccharide, carrying out hydrothermal treatment, adding carbon black powder impregnated with a silicon-containing solution, and kneading the carbon black powder with an extrusion aid and a peptizing agent to prepare the silicon-containing alumina carrier. The carbon black powder is used as the pore-expanding agent, the addition amount of the carbon black powder is required to be more than 10%, and the prepared carrier has low strength.

CN104646005A discloses a preparation method of a heavy oil demetallization catalyst, weighing pseudo-boehmite, adding peptizing agent, extrusion aid and pore-expanding agent, kneading, drying, roasting, spraying acid solution, and drying to obtain an alumina carrier, wherein the pore volume of the alumina carrier is 0.71-0.85, and the average pore diameter is 19-30 nm.

CN102847541A discloses a coal tar hydrodemetallization catalyst and a preparation method thereof, wherein an alumina carrier is treated by an organic acid solution, then is impregnated by an aluminum nitrate solution, and is dried and roasted to obtain a modified alumina carrier, and then an active component is loaded on the carrier. The method has complicated steps in the carrier modification process and can generate secondary pollution.

The pore volume of the catalyst prepared by the method is mostly below 0.9mL/g, the pore volume of macropores with the diameter of more than 20-30 nm accounts for less than 45% of the total pore volume, orifice blockage of smaller pore channels cannot be avoided, and the diffusion performance of the catalyst cannot be improved to the greatest extent.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a novel coal tar hydrogenation pretreatment catalyst with a macroporous structure and a preparation method thereof. The pore volume of macropores with the diameter of more than 20-30 nm of the catalyst prepared by the method accounts for 45-70% of the total pore volume, the diffusion performance is good, and the problems of diffusion and hydro-conversion of a large amount of asphaltene macromolecular substances in coal tar to the inside of the catalyst are effectively solved. The catalyst prepared by the method has larger pore volume, can contain more metals and carbon deposit, and prolongs the startup period of a hydrogenation device. The preparation process is simple, only a small amount of the composite pore-expanding agent is added, the energy consumption in the roasting process is low, and the product strength meets the industrial application requirements. The catalyst prepared by the invention can be used as hydrogenation protective agent, hydrogenation demetalization agent and asphaltene conversion catalyst carrier.

The invention provides a coal tar hydrogenation pretreatment catalyst, wherein,

the pore volume is 0.9-1.5 mL/g;

the specific surface area is 200-300 m²/g；

The most probable pore diameter is 15-30 nm;

the pore volume of macropores with the diameter of more than 20-30 nm accounts for 45-70% of the total pore volume.

Alumina is used as a carrier, VIB and VIII metal elements are used as active components, and the weight content of the active components in the hydrogenation pretreatment catalyst is 0.4-10 percent calculated by metal.

Phosphorus is taken as an auxiliary agent, and the weight content of the auxiliary agent phosphorus calculated by the element is 0.1-10%.

The invention also provides a preparation method of the coal tar hydrogenation pretreatment catalyst, which comprises the following steps:

(1) preparing an aluminum hydrate by adopting a titration method, adding a phosphorus-containing compound under the stirring condition, standing, cooling, washing and drying to obtain the phosphorus-containing pseudo-boehmite M.

(2) Mixing the phosphorus-containing pseudo-boehmite M with the composite pore-expanding agent and the extrusion aid, forming, drying and roasting to obtain an alumina carrier;

(3) preparing a metal solution containing molybdenum and/or tungsten and nickel and/or cobalt, and loading the metal on the carrier obtained in the step (2) in a saturated impregnation mode; washing the materials, drying at 50-120 ℃ for 2-4 hours, and then roasting at 400-700 ℃ for 2-6 hours, wherein the catalyst contains active metal accounting for 0.4-10% of the total weight of the catalyst, and the content of phosphorus element accounting for 0.1-10% of the total weight of the catalyst.

The preparation method of the coal tar hydrogenation pretreatment catalyst comprises the following steps of preparing a phosphorus-containing pseudo-boehmite M with a pore volume of 1.1-2.2 mL/g and a specific surface area of 130-500M²The most probable pore diameter is 15-35 nm.

The preparation method of the coal tar hydrogenation pretreatment catalyst comprises the step of preparing a composite pore-expanding agent from a boron-containing compound and polyoxyethylene ether.

The preparation method of the coal tar hydrogenation pretreatment catalyst comprises the step of preparing a catalyst, wherein the polyoxyethylene ether is one or more of alkylphenol polyoxyethylene, castor oil polyoxyethylene, fatty amine polyoxyethylene and fatty acid polyoxyethylene

The preparation method of the coal tar hydrogenation pretreatment catalyst provided by the invention is characterized in that the boron-containing compound is preferably one or more of boric acid, boron oxide and borate.

The preparation method of the coal tar hydrogenation pretreatment catalyst comprises the step of preferably adding 0.5-5% of boron-containing compound by weight of corresponding alumina in pseudo-boehmite dry glue powder.

The preparation method of the coal tar hydrogenation pretreatment catalyst provided by the invention is characterized in that the addition amount of the polyoxyethylene ether is preferably 0.5-3% of the weight of corresponding alumina in the pseudo-boehmite dry glue powder.

The preparation method of the coal tar hydrogenation pretreatment catalyst provided by the invention is characterized in that the extrusion aid is sesbania powder or starch preferably.

The preparation method of the coal tar hydrogenation pretreatment catalyst provided by the invention is characterized in that the addition amount of the extrusion aid is preferably 1-3% of the weight of corresponding alumina in the pseudo-boehmite dry glue powder.

The shape of the coal tar hydrogenation pretreatment catalyst can be changed according to different requirements.

Compared with the prior art, the pore volume of macropores with the diameter of more than 20-30 nm of the catalyst provided by the invention accounts for 45-70% of the total pore volume, the diffusion performance is better, and the problems of diffusion and hydro-conversion of a large amount of asphaltene macromolecular substances in coal tar to the inside of the catalyst are effectively solved; the catalyst prepared by the method has larger pore volume, can contain more metals and carbon deposit, and prolongs the startup period of a hydrogenation device; according to the method provided by the invention, an acidic peptizing agent is not required to be added in the preparation process, so that the damage of acid to the structure of the hydrated alumina particles is reduced, the pore structure of the alumina carrier is effectively protected, and the upper macroporous structure is preserved as much as possible; the pseudo-boehmite provided by the invention has good peptization performance, and a binder is not required to be added in the preparation process of the carrier, so that the roasting energy consumption is greatly reduced, and the product strength is improved; the compound pore-expanding ratio of the boron-containing compound and the polyoxyethylene ether is independently used, so that the pore volume of the obtained pore is larger, the addition amount of the pore-expanding agent is low, the production cost is reduced, and the strength of the carrier is improved.

The coal tar hydrogenation pretreatment catalyst provided by the invention can be used as a fixed bed hydrogenation catalyst, and can be particularly used as a hydrogenation protective agent, a demetalization catalyst, a deasphalted catalyst and other hydrogenation catalysts for heavy oil processing.

Detailed Description

The following examples illustrate the invention in detail: the present example is carried out on the premise of the technical solution of the present invention, and detailed embodiments and processes are given, but the scope of the present invention is not limited to the following examples, and experimental methods without specific conditions noted in the following examples are generally performed according to conventional conditions.