Method for producing catalytic reforming raw material by hydrofining inferior raw oil

文档序号：695673 发布日期：2021-05-04 浏览：24次中文

阅读说明：本技术 对劣质原料油进行加氢精制以拓宽生产催化重整原料的方法 (Method for producing catalytic reforming raw material by hydrofining inferior raw oil ) 是由鞠雪艳葛泮珠习远兵王哲陈文斌丁石于 2019-10-30 设计创作，主要内容包括：本发明涉及催化重整原料技术领域,具体公开了对劣质原料油进行加氢精制以拓宽生产催化重整原料的方法。该方法包括：在加氢反应条件下,将加氢精制催化剂、氢气和劣质原料油接触；加氢精制催化剂含有无机耐火组分、活性组分和羧酸；无机耐火组分含有氧化硅、氧化镁、氧化钙、氧化锆和氧化钛中的至少一种和部分活性组分；催化剂具有占总孔体积的60-95％的2-40nm的孔径和占总孔体积的0.5-30％的100-300nm的孔径；劣质原料油的硫含量≥600μg/g,氮含量≥10μg/g。本发明的方法能够对含有高硫、高氮等杂质的油品进行加氢处理,达到生产满足重整进料要求的精制油品,实现拓宽重整原料的目的。(The invention relates to the technical field of catalytic reforming raw materials, and particularly discloses a method for carrying out hydrofining on inferior raw oil to broaden the production of catalytic reforming raw materials. The method comprises the following steps: under the condition of hydrogenation reaction, contacting a hydrofining catalyst, hydrogen and inferior raw oil; the hydrofining catalyst contains inorganic refractory components, active components and carboxylic acid; the inorganic refractory component contains at least one of silicon oxide, magnesium oxide, calcium oxide, zirconium oxide and titanium oxide and a part of the active component; the catalyst has a pore diameter of 2-40nm accounting for 60-95% of the total pore volume and a pore diameter of 100-300nm accounting for 0.5-30% of the total pore volume; the sulfur content of the inferior raw oil is more than or equal to 600 mu g/g, and the nitrogen content is more than or equal to 10 mu g/g. The method of the invention can carry out hydrogenation treatment on the oil product containing high-sulfur, high-nitrogen and other impurities, thereby achieving the purposes of producing the refined oil product meeting the requirements of reforming feed and widening the reforming raw material.)

1. A method for hydrorefining inferior raw oil to broaden the production of catalytic reforming raw material is characterized by comprising the following steps: under the condition of hydrogenation reaction, contacting a hydrofining catalyst, hydrogen and inferior raw oil;

wherein the hydrofining catalyst contains an inorganic refractory component, a hydrodesulfurization catalytic active component and carboxylic acid;

wherein the inorganic refractory component contains at least one of silica, magnesia, calcia, zirconia and titania and a part of the hydrodesulfurization catalytic active component;

the catalyst has a pore diameter of 2-40nm and a pore diameter of 100-300nm, wherein the pore volume of the pore diameter of 2-40nm accounts for 60-95% of the total pore volume, and the pore volume of 100-300nm accounts for 0.5-30% of the total pore volume;

wherein the sulfur content of the inferior raw oil is more than 600 mug/g, and the nitrogen content is more than 10 mug/g.

2. The method according to claim 1, wherein the inferior raw oil is an oil containing ebullated bed hydrogenated naphtha or reprocessed gasoline, preferably a mixed oil of straight run naphtha and ebullated bed hydrogenated naphtha or reprocessed gasoline, more preferably, the content of ebullated bed hydrogenated naphtha or reprocessed gasoline in the mixed oil is 30-50 wt%;

preferably, the boiling range of the boiling bed hydrogenation naphtha is in the range of an initial boiling point to 180 ℃; and/or the distillation range of the oil product of the secondary processing gasoline is from the initial boiling point to 180 ℃.

3. The process of claim 1 or 2, wherein the hydrogenation reaction conditions are: the reaction pressure is 2-5MPa, the reaction temperature is 160-320 ℃, and the volume space velocity is 1.8-8h^-1The volume ratio of hydrogen to oil is 80-400Nm³/m³；

Preferably, the method comprises: under the condition of hydrogenation reaction, contacting a hydrofining catalyst with a mixture of hydrogen and inferior raw oil;

preferably, the method also comprises the steps of cooling the effluent after the hydrogenation reaction, separating to obtain hydrogen-rich gas and hydrogenated oil products, and recycling the hydrogen-rich gas.

4. The process according to claim 1, wherein the hydrodesulphurization catalytically active components are elements of group VIII metals and elements of group VIB metals;

wherein, in the hydrofining catalyst, the content of the VIII group metal element is 15-35 wt%, preferably 20-30 wt% based on the dry weight of the catalyst and calculated by oxide; the content of group VIB metal elements is from 35 to 75% by weight, preferably from 40 to 65% by weight;

the VIII group metal element is preferably at least one selected from iron, cobalt, nickel, ruthenium, rhodium and palladium, and the VIB group metal element is preferably at least one selected from chromium, molybdenum and tungsten;

preferably, the partial hydrodesulfurization catalytic active component is a part of VIII group metal elements, and the content of the VIII group metal elements is 60-90% of the total content of the VIII group metal elements.

5. The process as claimed in claim 1 or 4, wherein the pore volume of pores with a pore diameter of 2-40nm is 75-90% of the total pore volume and the pore volume of pores with a pore diameter of 100-300nm is 5-15% of the total pore volume;

preferably, the catalyst is a molded catalyst, and the shape of the catalyst is preferably cylindrical, cloverleaf or honeycomb;

preferably, the specific surface area of the hydrofining catalyst is 70-200m²Per gram, pore volume of 0.15-0.6mL/g, average pore diameter of 5-25 nm;

preferably, in the hydrofinishing catalyst, the pore volume of 2-4nm is no more than 10% of the total pore volume.

6. A process according to claim 1, 4 or 5, wherein the inorganic refractory component is present in an amount of from 5 to 40 wt%, preferably from 10 to 30 wt%, based on the dry weight of the catalyst;

preferably, the weight ratio of the carboxylic acid to the inorganic refractory component on a dry basis is from 0.1 to 0.8: 1, preferably 0.2 to 0.6: 1; the carboxylic acid is preferably at least one selected from C1-18 monobasic saturated carboxylic acid, C7-10 phenyl acid, citric acid, adipic acid, malonic acid, succinic acid, maleic acid, tartaric acid and the like;

preferably, the hydrofining catalyst also contains phosphorus element based on the dry weight of the catalyst and P₂O₅The content of the phosphorus element is 0.8 to 10 wt%, preferably 1 to 8 wt%.

7. The method of claim 1, wherein the hydrofinishing catalyst is prepared by a process comprising:

(1) mixing and roasting a precursor containing at least one of silicon oxide, magnesium oxide, calcium oxide, zirconium oxide and titanium oxide and a precursor of a part of hydrodesulfurization catalytic active component to obtain an inorganic refractory component;

(2) mixing carboxylic acid and the precursor of the residual hydrodesulfurization catalytic active component to obtain impregnation liquid;

(3) and mixing the inorganic refractory component with the impregnation liquid, and molding and drying the obtained mixture to obtain the hydrofining catalyst.

8. The process according to claim 7, wherein the precursors of the hydrodesulphurization catalytically active components are precursors of group VIII and VIB metallic elements;

wherein, the amount of the precursor of the VIII group metal element and the precursor of the VIB group metal element is that in the hydrofining catalyst, the content of the VIII group metal element is 15-35 wt%, preferably 20-30 wt% based on the dry weight of the catalyst and calculated by oxide; the content of group VIB metal elements is from 35 to 75% by weight, preferably from 40 to 65% by weight;

preferably, the precursor of the partial hydrodesulfurization catalytic active component is a partial precursor of the group VIII metal element, and the amount of the partial precursor of the group VIII metal element is 60-90% of the total amount of the precursor of the group VIII metal element.

9. The process according to claim 7 or 8, wherein in step (2), the weight ratio on a dry basis of the carboxylic acid to the inorganic refractory component is from 0.1 to 0.8: 1, preferably 0.2 to 0.6: 1; the carboxylic acid is preferably at least one selected from C1-18 monobasic saturated carboxylic acid, C7-10 benzoic acid, citric acid, adipic acid, malonic acid, succinic acid, maleic acid, tartaric acid and the like;

preferably, the impregnation liquid obtained in the step (2) further contains a phosphorus-containing substance, and the amount of the phosphorus-containing substance is determined by taking the dry weight of the hydrofining catalyst as a reference and taking P as a reference₂O₅The content of the phosphorus element is 0.8-10 wt%, preferably 1-8 wt%; the phosphorus-containing substance is preferably at least one selected from phosphoric acid, hypophosphorous acid, ammonium phosphate and ammonium dihydrogen phosphate;

preferably, in step (3), the inorganic refractory component is used in an amount such that the content of the inorganic refractory component in the hydrofining catalyst is 5 to 40% by weight, preferably 10 to 30% by weight, based on the dry weight of the hydrofining catalyst.

10. The method of claim 7, wherein in step (1), the roasting conditions comprise: the roasting temperature is 300-900 ℃, preferably 400-800 ℃; the roasting time is 1-15h, preferably 3-8 h;

preferably, in the step (3), the drying conditions include: the drying temperature is 50-250 ℃, preferably 100-200 ℃; the drying time is 2-10h, preferably 3-8 h.

11. The method of claim 7, wherein the silica precursor is at least one of silica sol, silica white, and silica dioxide; the magnesium oxide precursor is at least one of magnesium hydroxide, magnesium nitrate, magnesium carbonate, magnesium acetate and magnesium oxide; the precursor of the calcium oxide is at least one of calcium hydroxide, calcium carbonate, calcium oxalate, calcium nitrate, calcium acetate and calcium oxide; the zirconia precursor is at least one of zirconium hydroxide, zirconium carbonate, zirconium nitrate, zirconium acetate and zirconia; the precursor of the titanium oxide is at least one of titanium hydroxide, titanium nitrate, titanium acetate and zirconium oxide;

preferably, the average pore diameter of the precursors of the silicon oxide, the magnesium oxide, the calcium oxide, the zirconium oxide and the titanium oxide is not less than 10nm, the pore volume of the pore diameter of 2-6nm is not more than 15% of the total pore volume, and the pore volume of the pore diameter of 6-40nm is not less than 75% of the total pore volume.

Technical Field

The invention relates to the technical field of catalytic reforming raw materials, in particular to a method for producing a catalytic reforming material by hydrogenating inferior raw oil with high sulfur and high nitrogen content by using a novel hydrofining catalyst under the hydrogen condition to produce a refined oil product meeting the requirements of reforming feed, thereby widening the production of the catalytic reforming material.

Background

Naphtha is an important gasoline raw material and a chemical raw material, and can be used as a catalytic reforming raw material to produce aromatic hydrocarbon, hydrogen and the like. Naphtha is generally derived from straight run naphtha obtained by distillation of petroleum, and naphtha obtained by secondary processing, such as coker naphtha, cracker naphtha and naphtha obtained by fractional recovery from other apparatuses. However, the rapid development of the reforming industry has led to an insufficient supply of suitable reforming raw naphtha.

At present, the structure of crude oil processed globally changes, the processing proportion of heavy crude oil is higher and higher, therefore, more residual oil heavy raw materials need to be converted into novel light oil products, which becomes an important direction of world refining attention, and the residual oil hydrogenation technology is an effective method for solving the processing of heavy and poor crude oil. Compared with the fixed bed residual oil hydrogenation technology, the boiling bed residual oil hydrogenation technology can ensure the long-period stable operation of the device, and the aim of higher conversion rate and impurity removal rate is fulfilled. In recent years, the ebullated bed residual oil hydrogenation technology is developed rapidly, and the application prospect is wide.

At present, the residual oil hydrogenation boiling bed technology is rapidly developed in China, compared with the conventional residual oil hydrogenation device, the naphtha yield generated by the boiling bed technology is obviously improved, meanwhile, the boiling bed hydrogenation naphtha contains a large amount of naphthenic hydrocarbons, is a high-quality reforming pre-hydrogenation raw material, and contains a large amount of impurities such as sulfur, nitrogen and the like which are difficult to process. The catalyst adopted by the current catalytic reforming is a platinum-rhenium or platinum-tin bimetallic catalyst, which has strict requirements on impurities such as sulfur, nitrogen and the like in raw materials, requires that the contents of sulfur and nitrogen are both less than 0.5 mu g/g, and particularly requires that the content of silicon is as less than 0.1 mu g/g as far as possible, so that how to use the oil products with high sulfur and nitrogen contents such as boiling bed hydrogenation naphtha is a difficult problem to solve.

CN102041092A discloses a method for widening catalytic reforming raw materials, which specifically comprises the steps of mixing FCC stable gasoline with high sulfur and high olefin with straight-run naphtha for olefin saturation, desulfurization and denitrification reaction, and feeding hydrogenated gasoline into an evaporation tower for steam stripping fractionation to obtain refined naphtha meeting the requirements of reforming feed; the method can carry out hydrotreating on the mixed naphtha of the FCC stable gasoline with the blending proportion of more than 50 percent to obtain the refined naphtha with the impurity content meeting the reforming feeding requirement, thereby widening the source of the reforming raw material to a certain extent. However, this process uses FCC gasoline as feedstock, which contains relatively large amounts of olefins, especially diolefins, and has a detrimental effect on the cycle time and the actual impurity removal.

CN1903995A discloses a method for using light hydrocarbon as catalytic reforming raw material, which specifically comprises contacting a light hydrocarbon as raw material with a light hydrocarbon conversion catalyst at 300-600 ℃ to react light olefin and convert the light olefin into naphtha, contacting the obtained naphtha with a hydrorefining catalyst, hydrorefining to obtain refined naphtha, and finally converting the refined naphtha into aromatic hydrocarbon or high octane gasoline component by catalytic reforming. The raw material source of the process is light hydrocarbon, the raw material source of catalytic reforming is expanded, but the first step of light hydrocarbon raw material conversion needs to design superposition, oligomerization and cyclodehydrogenation reactions, the process flow is more complex, and the equipment investment is larger.

In addition, the method for widening the source of the reforming raw material is applied to a high-nitrogen high-sulfur raw material, namely boiling bed hydrogenation naphtha, and hydrogenated oil products meeting the requirements are difficult to produce.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a method for carrying out hydrofining on inferior raw oil to broaden the production of catalytic reforming.

In order to achieve the above object, the present invention provides a process for hydrorefining inferior feedstock oil to broaden the production of catalytic reforming feedstock, the process comprising: under the condition of hydrogenation reaction, contacting a hydrofining catalyst, hydrogen and inferior raw oil;

wherein the hydrofining catalyst contains an inorganic refractory component, a hydrodesulfurization catalytic active component and carboxylic acid;

wherein the inorganic refractory component contains at least one of silica, magnesia, calcia, zirconia and titania and a part of the hydrodesulfurization catalytic active component;

wherein the sulfur content of the inferior raw oil is more than 600 mug/g, and the nitrogen content is more than 10 mug/g.

Preferably, the preparation method of the hydrofining catalyst comprises the following steps:

(2) mixing carboxylic acid and the precursor of the residual hydrodesulfurization catalytic active component to obtain impregnation liquid;

(3) and mixing the inorganic refractory component with the impregnation liquid, and molding and drying the obtained mixture to obtain the hydrofining catalyst.

The invention has the following advantages:

(1) the pore channel structures of the catalyst adopted by the invention are respectively concentrated between 2-40nm and 100-300 nm. In the poor-quality distillate oil, the size of reactant molecules is larger, so that a larger reaction space is inevitably needed, and the pore passages with the size of 100-300nm in the catalyst can provide enough places for the diffusion of the reactants, so that the accessibility of the reactants and an active center is promoted, and the performance of the catalyst is improved.

(2) The catalyst prepared by the conventional impregnation method has low metal loading, the content of the VIII group metal is usually less than 10%, and the content of the VIB group metal is usually less than 35%. This limits the number of active metal sites in the catalyst and the activity of the catalyst does not reach higher levels. The catalyst prepared by the kneading method can improve the loading of active metal in the catalyst, but the hydrofining activity of the catalyst is not high, and the utilization rate of the active metal is low. The current catalyst preparation generally does not employ this method. In a preferred method of the invention, however, a portion of the hydrodesulfurization catalytically active component, more preferably a portion of the group VIII metal, is mixed into a support precursor and calcined to form the inorganic refractory powder. Then the impregnation liquid containing the residual active metal is mixed with the inorganic refractory powder, so that the catalyst has higher content of hydrogenation active components, and the capability of removing impurities is obviously improved, thereby being obviously beneficial to removing sulfur and nitrogen impurities in the reforming raw material.

(3) The method provided by the invention is used for carrying out hydrotreating on the inferior raw oil with the sulfur content of more than 600 mug/g and the nitrogen content of more than 10 mug/g, so that the refined oil product with the impurity content meeting the requirement of reforming feed can be obtained, the problem of insufficient reforming raw material is solved, and the source of the reforming raw material is widened.

(4) The method has the advantages of simple process flow, mature technology and flexible operation, and is suitable for newly built naphtha hydrogenation devices and old device extension and reconstruction.

(5) The method of the invention can treat not only the oil product containing naphtha hydrogenation produced by a boiling bed, but also the oil product containing secondary processing gasoline.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

In a first aspect, the present invention provides a process for the hydrofinishing of a poor feed oil to broaden the production of catalytic reforming feedstocks, comprising: under the condition of hydrogenation reaction, contacting a hydrofining catalyst, hydrogen and inferior raw oil;

wherein the hydrofining catalyst contains an inorganic refractory component, a hydrodesulfurization catalytic active component and carboxylic acid;

wherein the inorganic refractory component contains at least one of silica, magnesia, calcia, zirconia and titania and a part of the hydrodesulfurization catalytic active component;

wherein the sulfur content of the inferior raw oil is more than 600 mug/g, and the nitrogen content is more than 10 mug/g.

In the present invention, the type of the inferior feedstock is not particularly limited, and may be any oil having a sulfur nitrogen content as described above, and preferably, the inferior feedstock is a mixed oil of virgin naphtha and ebullated bed hydrogenated naphtha or reprocessed gasoline, and more preferably, in order to improve the effect of hydrorefining the inferior feedstock, the content of the ebullated bed hydrogenated naphtha or reprocessed gasoline in the mixed oil is not particularly limited, and is preferably 30 to 50 wt%, for example, 30 wt%, 32 wt%, 34 wt%, 36 wt%, 38 wt%, 40 wt%, 42 wt%, 44 wt%, 46 wt%, 48 wt%, 50 wt%.

According to the invention, the boiling range of the boiling bed hydrogenation naphtha can be the boiling range of the conventional boiling bed hydrogenation naphtha, and preferably, the boiling range of the boiling bed hydrogenation naphtha is from the initial boiling point to 180 ℃.

According to the present invention, the distillation range of the secondary processed gasoline may be that of conventional secondary processed gasoline, and preferably, the distillation range of the secondary processed gasoline is from the initial boiling point to 180 ℃.

According to the invention, the conditions of the hydrogenation reaction can be conventional conditions for catalytic reforming, and according to a preferred embodiment of the invention, the reaction pressure is 2-5MPa, the reaction temperature is 160-320 ℃, and the volume space velocity is 1.8-8h^-1The volume ratio of hydrogen to oil is 80-400Nm³/m³。

Preferably, the reaction pressure is 3 to 5MPa, and more preferably 3 to 4MPa, and under the preferable conditions, the sulfur and nitrogen removal rate in the inferior raw oil can be further improved.

Preferably, the reaction temperature is 200-300 ℃, and more preferably 210-240 ℃, under the preferable conditions, the sulfur and nitrogen removal rate in the inferior raw oil can be further improved.

Preferably, the volume space velocity is 2-6h^-1More preferably 3.5 to 5 hours^-1Under the preferable conditions, the sulfur and nitrogen removal rate of the inferior raw oil can be further improved.

Preferably, the hydrogen-oil volume ratio is 100-300Nm³/m³More preferably, 120-150Nm³/m³Under the preferable conditions, the sulfur and nitrogen removal rate of the inferior raw oil can be further improved.

According to a preferred embodiment of the present invention, the hydrofinishing method comprises: firstly, mixing the poor-quality raw oil with hydrogen to obtain a mixture, then heating the mixture to a reaction temperature, and contacting the mixture with the hydrofining catalyst to carry out the hydrogenation reaction.

More specifically, the mixture is introduced into the inlet of the hydrogenation reactor and is in contact reaction with the hydrofining catalyst under the condition that the inlet temperature is 160-320 ℃.

According to the invention, after the reaction contact, the method of the hydrofining method further comprises the step of cooling and separating the obtained reactant to obtain hydrogen-rich gas and refined hydrogenated oil, wherein the refined hydrogenated oil is the refined oil meeting the requirements of reforming feed production, and the hydrogen-rich gas can be recycled.

The silicon oxide, the magnesium oxide, the calcium oxide, the zirconium oxide and the titanium oxide contained in the inorganic refractory component are basically inert substances, and are difficult to combine with the VIII element to form a compound with a stable structure, so that the utilization rate of the VIII element is improved.

Preferably, the pore volume of pores with a pore diameter of 2-40nm accounts for 75-90% of the total pore volume, and the pore volume of pores with a pore diameter of 100-300nm accounts for 5-15% of the total pore volume. Wherein the pore volume of pores with a diameter of 2-4nm is not more than 10% of the total pore volume.

According to the invention, the specific surface area of the catalyst and the pore distribution, the pore diameter and the pore volume of the catalyst between 2 and 40nm are measured by a low-temperature nitrogen adsorption method (meeting the GB/T5816-1995 standard), and the pore distribution, the pore diameter and the pore volume of the catalyst between 100 and 300nm are measured by a mercury intrusion method. The pore volume of the catalyst with the pore diameter less than 100nm is measured by a low-temperature nitrogen adsorption method, the pore volume of the catalyst with the pore diameter more than 100nm is measured by a mercury intrusion method, and the pore volume of the catalyst is the sum of the pore volume of the catalyst and the pore volume of the catalyst. The average pore diameter was calculated according to the cylindrical pore model (average pore diameter ═ total pore volume × 4000/specific surface area).

Preferably, the specific surface area of the hydrofining catalyst is 70-200m²A/g, preferably from 90 to 180m²Pore volume of 0.15 to 0.6mL/g, preferably 0.2 to 0.4mL/g, and average pore diameter of 5 to 25nm, preferably 8 to 15 nm. Wherein, the specific surface area, the pore volume and the average pore diameter are measured after the catalyst is calcined at 400 ℃ for 3 hours.

According to the invention, the pore diameter of 2-40nm means a pore diameter of 2nm or more and less than 40nm, and the pore diameter of 100-300nm means a pore diameter of 100nm or more and less than 300nm, unless otherwise stated. The average pore diameter of 5 to 25nm means that the average of the pore diameters of all pores of the catalyst is not less than 5nm and not more than 25 nm. The pore diameter of 2-4nm is larger than or equal to 2nm and smaller than 4 nm.

According to the invention, the hydrogen desulfurization catalytically active component may be a component of an active component that is available in the prior art for a hydrofinishing catalyst, for example, the active components may be a group VIII metal element and a group VIB metal element. Wherein the content of the active component may also vary within wide limits, it is preferred that the content of group VIII metal elements in the hydrofinishing catalyst is from 15 to 35 wt.%, preferably from 20 to 30 wt.%, based on the dry weight of the catalyst and calculated as oxide; the content of group VIB metal elements is from 35 to 75% by weight, preferably from 40 to 65% by weight.

According to a preferred embodiment of the present invention, the group VIII metal element is selected from at least one of iron, cobalt, nickel, ruthenium, rhodium and palladium, and the group VIB metal element is selected from at least one of chromium, molybdenum and tungsten.

The inventors of the present invention have found in their studies that, by preferably including a part of the group VIII metal element in the inorganic refractory component, the content of the active component in the catalyst can be further increased, thereby further improving the hydrorefining performance of the catalyst. While the amount ratio of the group VIII metal element contained in the inorganic refractory component is not particularly limited and may be selected from a wide range, it is preferable that the content of the partial group VIII metal element is 60 to 90% of the total content of the group VIII metal elements.

According to the present invention, it is preferred that the inorganic refractory component is present in an amount of 5 to 40 wt%, more preferably 10 to 30 wt%, based on the dry weight of the catalyst.

Here, the dry weight of the inorganic refractory powder is a weight measured by calcining a sample at 600 ℃ for 4 hours, and the dry weight of the catalyst is a weight measured by calcining a sample at 400 ℃ for 3 hours. The dry basis weights appearing hereinafter are equally applicable to this definition. That is, in the case where there is no reverse explanation, the dry weight of the inorganic refractory powder as described herein means the weight determined by calcining a sample at 600 ℃ for 4 hours, and the dry weight of the catalyst is determined by calcining a sample at 400 ℃ for 3 hours. It can be known to those skilled in the art that organic acids contained in the catalyst are decomposed and volatilized at high temperatures in the case of calculation based on dry weight, and thus the content of the organic acids is not calculated based on dry weight.

The carboxylic acid compound is introduced into the hydrofining catalyst, so that the active components of the catalyst can be protected, and the activity of the catalyst can be improved. Therefore, the carboxylic acid is introduced into the catalyst to protect the catalyst active component and improve the catalyst activity, and the amount of the carboxylic acid added is not particularly limited. According to a preferred embodiment of the invention, the weight ratio, on a dry basis, of the carboxylic acid to the inorganic refractory component is between 0.1 and 0.8: 1, preferably 0.2 to 0.6: 1.

preferably, the carboxylic acid is selected from at least one of C1-C18 monobasic saturated carboxylic acids (e.g., C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18 monobasic saturated carboxylic acids) (e.g., but not limited to, formic acid, acetic acid, propionic acid, octanoic acid, pentanoic acid, hexanoic acid, decanoic acid, octadecanoic acid), C7-C10 phenyl acids (e.g., C7, C8, C9, C10 phenyl acids) (e.g., but not limited to, benzoic acid, phenylacetic acid, phthalic acid, terephthalic acid), citric acid, adipic acid, malonic acid, succinic acid, maleic acid, tartaric acid, and the like.

According to a preferred embodiment of the present invention, the hydrorefining catalyst further contains phosphorus, preferably P, to further improve the performance of the catalyst₂O₅Exist in the form of (1). Preferably, based on the dry weight of the catalyst and expressed as P₂O₅The content of the phosphorus element is 0.8 to 10% by weight, more preferably 1 to 8% by weight.

According to the present invention, preferably, the catalyst is a shaped catalyst, and the shape of the catalyst is preferably a cylinder, a clover or a honeycomb.

According to a preferred embodiment of the present invention, the method for preparing the hydrofinishing catalyst comprises:

(2) mixing carboxylic acid and the precursor of the residual hydrodesulfurization catalytic active component to obtain impregnation liquid;

(3) and mixing the inorganic refractory component with the impregnation liquid, and molding and drying the obtained mixture to obtain the hydrofining catalyst.

According to the invention, the precursors of the hydrodesulfurization catalytic active components are preferably precursors of group VIII metal elements and of group VIB metal elements; the precursors of the VIII group metal elements and the VIB group metal elements are used in such amounts that the contents of the VIII group metal elements and the VIB group metal elements are respectively the contents described above based on the dry weight of the catalyst and calculated by oxides, and the selection of the specific elements is also performed as described above.

According to the present invention, in the precursor of the hydrodesulfurization catalytic active component, the precursor of the iron element may include, but is not limited to, one or more of iron nitrate, iron oxide, basic iron carbonate and iron acetate, the precursor of the cobalt element may include, but is not limited to, one or more of cobalt nitrate, basic cobalt carbonate, cobalt acetate and cobalt oxide, the precursor of the nickel element may include, but is not limited to, one or more of nickel nitrate, basic nickel carbonate, nickel acetate and nickel oxide, the precursor of the ruthenium element may include, but is not limited to, one or more of ruthenium nitrate, ruthenium acetate, ruthenium oxide and ruthenium hydroxide, the precursor of the rhodium element may include, but is not limited to, one or more of rhodium nitrate, rhodium hydroxide and rhodium oxide, and the precursor of the palladium element may include, but is not limited to, one or more of palladium nitrate, palladium oxide and palladium hydroxide, the precursors of the chromium element can include but are not limited to one or more of chromium nitrate, chromium oxide, chromium hydroxide and chromium acetate, the precursors of the molybdenum element can include but is not limited to one or more of ammonium heptamolybdate, ammonium molybdate, ammonium phosphomolybdate and molybdenum oxide, and the precursors of the tungsten element can include but is not limited to one or more of ammonium metatungstate, ammonium ethylmetatungstate and tungsten oxide.

The inventor of the present invention found in research that, preferably, by preparing a part of the precursor of the group VIII metal element into the inorganic refractory component and preparing the rest of the precursor of the group VIII metal element and the precursor of the group VIB metal element together into an impregnation solution to impregnate the inorganic refractory component, the content of the active component in the catalyst can be further increased, thereby further improving the hydrofining performance of the catalyst. While the amount ratio of the precursor of the group VIII metal element used for preparing the inorganic refractory component is not particularly limited and may be selected from a wide range, it is preferable that the amount of the partial precursor of the group VIII metal element is 60 to 90% of the total amount of the precursor of the group VIII metal element in step (1).

According to the invention, in the step (1), the precursor of silica, magnesia, calcia, zirconia, titania can be various substances which can provide silica, magnesia, calcia, zirconia, titania under the roasting condition, for example, the silica precursor can be silica sol, silica white, silica dioxide, etc.; the magnesium oxide precursor is magnesium hydroxide, magnesium nitrate, magnesium carbonate, magnesium acetate, magnesium oxide and the like; the precursor of the calcium oxide is calcium hydroxide, calcium carbonate, calcium oxalate, calcium nitrate, calcium acetate, calcium oxide and the like; the zirconia precursor is zirconium hydroxide, zirconium carbonate, zirconium nitrate, zirconium acetate, zirconia and the like; the precursor of the titanium oxide is titanium hydroxide, titanium nitrate, titanium acetate, zirconium oxide and the like.

In step (3), the inorganic refractory component is used in an amount such that the content of the inorganic refractory component in the hydrofinishing catalyst is 5 to 40% by weight, preferably 10 to 30% by weight, based on the dry weight of the hydrofinishing catalyst.

In step (2), the amount and selection of the carboxylic acid are described in detail above, and are not repeated here.

According to the invention, the carboxylic acid substances are introduced into the impregnation liquid, so that the hydrodesulfurization catalytic active component can be effectively protected, and the catalyst can be promoted to be molded, thereby effectively improving the performance of the catalyst.

In order to further improve the performance of the finally prepared catalyst, the average pore diameters of the silicon oxide, the magnesium oxide, the calcium oxide, the zirconium oxide and the titanium oxide precursors are not less than 10nm, the pore volume of the pore diameters of 2-6nm accounts for no more than 15% of the total pore volume, and the pore volume of the pore diameters of 6-40nm accounts for no less than 75% of the total pore volume.

According to the invention, in order to further improve the solubility of the precursor of the hydrodesulfurization catalytic active component in the prepared impregnation solution and improve the performance of the finally prepared catalyst, a phosphorus-containing substance is preferably added in the preparation process of the impregnation solution, and the phosphorus-containing substance is preferably a phosphorus-containing inorganic acid and is further preferably at least one of phosphoric acid, hypophosphorous acid, ammonium phosphate and ammonium dihydrogen phosphate. Further preferably, the phosphorus-containing material is used in an amount such that the final catalyst is prepared on a dry weight basis and is P₂O₅The content of the phosphorus element is 0.8 to 10% by weight, preferably 1 to 8% by weight, more preferably 2 to 8% by weight.

According to a preferred embodiment of the invention, in the preparation of the impregnation solution, the organic carboxylic acid compound and the precursors containing the group VIB metal element and the group VIII metal element are added to the aqueous solution of the phosphorus-containing substance, and then stirred at 40-100 ℃ for 1-8h until all the organic carboxylic acid compound and the precursors are dissolved. The order of addition of the organic carboxylic acid compound, the phosphorus-containing substance, and the metal element precursor may be interchanged.

According to the invention, in the step (1), the roasting conditions can be selected within a wide range, and preferably, the roasting temperature is 300-900 ℃, preferably 400-700 ℃; the roasting time is 1-15h, preferably 3-8 h.

According to the present invention, in the step (3), the drying conditions can be selected within a wide range, and preferably, the drying temperature is 50-250 ℃, preferably 100-200 ℃; the drying time is 2-10h, preferably 3-8 h.

According to the invention, the forming mode can be various existing forming methods, such as extrusion molding and rolling ball molding. The extrusion molding can be performed according to the prior art, and the inorganic refractory component to be extruded and molded and the impregnation solution containing the metal component are uniformly mixed and then extruded into a required shape, such as a cylinder, a clover shape, a honeycomb shape and the like.

In the prior art, the steps for preparing a hydrofinishing catalyst generally comprise: (1) mixing an alumina precursor (such as pseudo-boehmite) or a precursor containing other powder and elements, and then extruding and mixing the mixture with a peptizing agent and an auxiliary agent, (2) preparing and forming the mixture in a strip extruding mode, and (3) roasting the formed alumina precursor to prepare the alumina carrier; (4) preparing an impregnation solution containing a metal component; (5) uniformly dipping the calcined alumina carrier into the dipping solution to prepare a catalyst precursor; (6) and drying or roasting the catalyst precursor to obtain the hydrofining catalyst. Therefore, the preparation process is long and the manufacturing cost is high. As mentioned above, the hydrogenation catalyst provided by the invention has a short preparation process, and can greatly save the preparation cost and the preparation time. On the other hand, the preparation of the catalyst does not add peptizing agent nitric acid and assistant sesbania squeezing powder, thereby reducing the material cost and the environmental protection cost and realizing the green manufacture of the catalyst.

In addition, the catalyst pore channel structure provided by the invention is respectively concentrated between 2-40nm and 100-300 nm. The pore channels with the size of 100-300nm in the catalyst can provide larger sites for the diffusion of reactants, and promote the accessibility of the reactants and active centers, thereby improving the performance of the catalyst.

The present invention will be described in detail below by way of examples.

In the following examples and comparative examples, the composition of the catalyst was calculated from the amounts charged. The mass fractions of sulfur and nitrogen in the product were analyzed using a sulfur-nitrogen analyzer (model number TN/TS3000, available from seimer feishei), and the content of aromatic hydrocarbons was analyzed by near infrared spectroscopy. The specific surface area of the catalyst and the pore distribution, the pore diameter and the pore volume of the catalyst between 2 and 40nm are measured by a low-temperature nitrogen adsorption method (meeting the GB/T5816-1995 standard), and the pore distribution, the pore diameter and the pore volume of the catalyst between 100 and 300nm are measured by a mercury intrusion method. The average pore diameter of the catalyst was calculated according to the cylindrical pore model (average pore diameter ═ total pore volume × 4000/specific surface area).

Preparation example 1

This preparation example is intended to explain a hydrorefining catalyst and a method for producing the same.

(1) Commercially available white carbon black (specific surface area: 220 m)²Per g, the average pore diameter is 12.7nm) and basic cobalt carbonate powder are uniformly mixed and then roasted at 400 ℃ for 3h to obtain the cobalt-containing inorganic refractory powder.

Wherein the amount of basic cobalt carbonate used corresponds to a cobalt (calculated as cobalt oxide) content of the catalyst of 22.0 wt.%.

(2) Adding a certain amount of MoO₃And respectively adding the basic cobalt carbonate and the citric acid into the aqueous solution containing the phosphoric acid, and heating and stirring the mixture until the basic cobalt carbonate and the citric acid are completely dissolved to obtain the impregnation solution containing the active metal.

Wherein the mass of the citric acid is 20 weight percent of the mass of the inorganic refractory component.

(3) The impregnating solution and the inorganic refractory component are uniformly mixed, and then extruded into strips for forming. The catalyst A1 in the oxidized state was prepared by drying at 200 ℃ for 3h to give a particle size of 1.6 mm.

Wherein the impregnating solution and the cobalt-containing inorganic refractory powder are mixed in such a proportion that the content of molybdenum oxide is 55.0 wt%, the content of cobalt oxide is 30.0 wt%, and P is in the catalyst, based on the dry weight of the catalyst and calculated as an oxide₂O₅The content was 5% by weight, and the content of the inorganic refractory component was 10.0% by weight.

After the catalyst A1 is roasted at 400 ℃ for 3h, the pore size distribution of the catalyst A is analyzed by using low-temperature nitrogen adsorption and mercury porosimetry. The specific surface area of the catalyst was 96.0m²(ii)/g, the pore diameter distribution was 2 to 40nm and 100-300nm, wherein the ratio of the pore volume of 2 to 40nm to the total pore volume was 86.6% (wherein the ratio of the pore volume of 2 to 4nm to the total pore volume was 9.5%), the ratio of the pore volume of 100-300nm to the total pore volume was 7.2%, the pore volume was 0.26mL/g, and the average pore diameter was 10.8 nm.

Preparation example 2

The preparation example is used for the hydrofining catalyst and the preparation method thereof.

The preparation of hydrorefining catalyst A2 was carried out according to the method of preparation example 1, except that in step (1) no group VIII metal element was introduced, but the same amount of group VIB metal element was introduced, the rest being the same, and the characterization was carried out according to the method of preparation example 1, with the parameters within the scope of the invention.

Comparative preparation example 1

This comparative example is illustrative of an existing hydrofinishing catalyst and method of making the same.

Commercially available white carbon black (specific surface area: 220 m)²The average pore diameter is 12.7nm), and basic cobalt carbonate powder are uniformly mixed without a roasting step to obtain the inorganic refractory powder containing cobalt. Wherein the amount of basic cobalt carbonate used corresponds to a cobalt (calculated as cobalt oxide) content of the catalyst of 22.0 wt.%. Then, an impregnation solution was prepared in accordance with the procedure (2) of preparation example 1, and a catalyst D1 was prepared in accordance with the procedure (3) of preparation example 1, the inorganic refractory components and the metal composition in the dry basis of the catalyst being the same as those of the catalyst of preparation example 1.

Comparative preparation example 2

This comparative example is illustrative of an existing hydrofinishing catalyst and method of making the same.

The preparation of hydrorefining catalyst D2 was carried out in accordance with the procedure in preparation example 1, except that no organic acid was added in the preparation of the active component solution, and the remainder was the same.

Comparative preparation example 3

This comparative example is illustrative of an existing hydrofinishing catalyst and method of making the same.

The preparation of hydrorefining catalyst D3 was carried out according to the method of preparation example 1, except that only white carbon black was replaced with pseudo boehmite powder, and the rest was the same.

Comparative preparation example 4

This comparative example is illustrative of an existing hydrofinishing catalyst and method of making the same.

The preparation of a hydrorefining catalyst D4 was carried out in accordance with the procedure of preparation example 1, except that the group VIII metal element was not introduced in step (1), and the group VIII metal element was completely introduced in step (2), and the rest was the same.

Examples and comparative examples

The specific hydrocarbon composition properties of the ebullated-bed hydrogenated naphtha used in the following examples are shown in table 1, and the properties of the mixture of ebullated-bed naphtha and straight-run naphtha are shown in table 2.

TABLE 1 Hydrocarbon family composition of ebullated bed hydrogenated naphtha

wt％	N-alkanes	Isoalkanes	Cycloalkanes	Aromatic hydrocarbons	Olefins
						C4		0	0
C5	10.62	4.05	1.33		0.53
						C6	7.02	4.31	4.76	0.17	0.53
C7	5.94	3.73	4.41	1.83	0.35
						C8	4.5	5.55	4.5	1.24	0.09
C9	3.87	5.55	5.58	4.2
						C10+	0.54	10.33	3.42	1.05
Total up to	32.49	33.52	24	8.49	1.5

Table 2 summary of properties of the blended feedstocks

Catalyst sulfidation

Each catalyst prepared as above employs a temperature programmed sulfiding process to convert an oxidized catalyst to a sulfided catalyst. The vulcanization conditions are as follows: the vulcanization pressure is 6.4MPa, and the vulcanized oil contains CS₂2% by weight of kerosene, the volume space velocity being 2h^-1And the hydrogen-oil ratio is 300v/v, the constant temperature is kept for 6h at 230 ℃/h, then the temperature is increased to 320 ℃ for vulcanization for 8h, and the temperature increase rate of each stage is 10 ℃/h.

Example 1