阅读说明：本技术 一种重油加氢处理方法 (Heavy oil hydrotreating method ) 是由 聂鑫鹏 刘涛 邵志才 戴立顺 邓中活 施瑢 任亮 赵宁 贾燕子 胡大为 孙淑玲 于 2018-08-01 设计创作，主要内容包括：本发明涉及重油加氢处理领域,公开了一种重油加氢处理方法,该方法包括：在氢气存在下,(1)将重油原料与加氢保护催化剂接触,得到第一物料；(2)将所述第一物料与第一加氢脱金属催化剂接触,得到第二物料；(3)将所述第二物料与加氢脱硫催化剂接触,得到第三物料；该方法还包括向第一物料和/或第二物料中混入油溶性催化剂。采用该方法能够有效提高重油加氢处理方法的加氢脱硫脱氮脱残炭活性,提高沥青质的转化,防止沥青质析出,且能够转化积碳前驱物,减少催化剂积碳,装置运转周期长。(The invention relates to the field of heavy oil hydrotreatment, and discloses a heavy oil hydrotreatment method, which comprises the following steps: in the presence of hydrogen, (1) contacting a heavy oil raw material with a hydrogenation protection catalyst to obtain a first material; (2) contacting the first material with a first hydrodemetallization catalyst to obtain a second material; (3) contacting the second material with a hydrodesulfurization catalyst to obtain a third material; the method further includes mixing an oil soluble catalyst into the first material and/or the second material. By adopting the method, the hydrodesulfurization, denitrification and carbon residue removal activity of the heavy oil hydrotreating method can be effectively improved, the conversion of asphaltene is improved, the precipitation of asphaltene is prevented, carbon deposition precursors can be converted, the carbon deposition of a catalyst is reduced, and the device has long operation period.)

1. A process for the hydroprocessing of heavy oils, the process comprising: in the presence of hydrogen, the reaction mixture is,

(1) contacting a heavy oil raw material with a hydrogenation protection catalyst to obtain a first material;

(2) contacting the first material with a first hydrodemetallization catalyst to obtain a second material;

(3) contacting the second material with a hydrodesulfurization catalyst to obtain a third material;

the method further includes mixing an oil soluble catalyst into the first material and/or the second material.

2. The method according to claim 1, wherein the oil-soluble catalyst is added in an amount of 10 to 200 μ g/g, preferably 20 to 100 μ g/g, and more preferably 30 to 70 μ g/g, based on the total weight of the first material when the oil-soluble catalyst is mixed into the first material; when the oil-soluble catalyst is mixed into the second material, the amount of the oil-soluble catalyst added is 10 to 150. mu.g/g, preferably 20 to 80. mu.g/g, and more preferably 20 to 60. mu.g/g, based on the total weight of the second material.

3. The process according to claim 1 or 2, wherein the oil-soluble catalyst is selected from at least one of a polycarbonyl compound containing a group VIB and/or group VIII metal, a naphthenate compound, an isooctanoate compound, and a porphyrin-based chelate; preferably, the group VIB metal is at least one of Fe, Co and Ni, and the group VIII metal is Mo; further preferably, the oil-soluble catalyst is selected from at least one of molybdenum naphthenate, iron naphthenate, molybdenum isooctanoate, molybdenum hexacarbonyl, vanadium naphthenate, iron pentacarbonyl, and nickel tetraphenylporphyrin.

4. The method of any one of claims 1 to 3, wherein the method is carried out in a heavy oil hydrogenation apparatus, wherein the heavy oil hydrogenation apparatus is sequentially filled with the hydrogenation protection catalyst, the first hydrodemetallization catalyst and the hydrodesulfurization catalyst in the direction of the material flow, and the loading amount of the hydrogenation protection catalyst is 1 to 20 vol%, the loading amount of the first hydrodemetallization catalyst is 10 to 70 vol% and the loading amount of the hydrodesulfurization catalyst is 10 to 70 vol%, based on the total volume of the filled catalysts;

preferably, the loading amount of the hydrogenation protection catalyst is 2-15 vol%, the loading amount of the first hydrodemetallization catalyst is 30-70 vol%, and the loading amount of the hydrodesulfurization catalyst is 20-60 vol%, based on the total volume of the loaded catalyst.

5. The process of any of claims 1-4, wherein each of the hydro-protective catalyst, first hydrodemetallization catalyst, and hydrodesulfurization catalyst independently comprises a support and an active metal component supported on the support, the active metal component being selected from at least one of group VIB and/or group VIII metal elements;

preferably, in the hydrogenation protection catalyst, the content of the active metal component is 1-12 wt% in terms of oxide based on the total amount of the hydrogenation protection catalyst;

preferably, the content of the active metal component in the first hydrodemetallization catalyst is 6-15 wt% calculated by oxide based on the total amount of the first hydrodemetallization catalyst;

preferably, the hydrodesulfurization catalyst has an active metal component content of 8 to 25 wt.% in terms of oxide, based on the total amount of the hydrodesulfurization catalyst.

6. The method of any one of claims 1-5,

the average pore diameter of the hydrogenation protection catalyst is 18-30nm, and the average particle size is 1.3-50 mm;

preferably, the average pore diameter of the first hydrodemetallization catalyst is 10-20nm, and the average particle size is 0.8-5 mm;

preferably, the hydrodesulfurization catalyst has an average pore diameter of 8 to 15nm and an average particle diameter of 0.6 to 2 mm.

7. The process of any one of claims 1-6, wherein the process is carried out under hydrotreating conditions comprising: the temperature is 320-450 ℃, the reaction pressure is 6-25MPa, and the liquid hourly space velocity is 0.1-1h^-1The volume ratio of hydrogen to oil is 250-1500;

preferably, the hydrotreating conditions include: the temperature is 350-420 ℃, the reaction pressure is 12-20MPa, and the liquid hourly space velocity is 0.2-0.4h^-1The volume ratio of hydrogen to oil is 300-1000.

8. The process of any of claims 1-3, further comprising contacting the third material with a second hydrodemetallization catalyst;

preferably, the method is carried out in a heavy oil hydrogenation device, wherein a hydrogenation protection catalyst, a first hydrogenation demetallization catalyst, a hydrodesulfurization catalyst and a second hydrogenation demetallization catalyst are sequentially filled in the heavy oil hydrogenation device along the material flow direction, and the filling amount of the hydrogenation protection catalyst is 1-20 vol%, the filling amount of the first hydrogenation demetallization catalyst is 5-60 vol%, the filling amount of the hydrodesulfurization catalyst is 5-60 vol%, and the filling amount of the second hydrogenation demetallization catalyst is 2-20 vol% based on the total volume of the filled catalysts;

preferably, the loading amount of the hydrogenation protection catalyst is 2-15 vol%, the loading amount of the first hydrodemetallization catalyst is 25-60 vol%, the loading amount of the hydrodesulfurization catalyst is 15-50 vol%, and the loading amount of the second hydrodemetallization catalyst is 5-10 vol% based on the total volume of the loaded catalyst.

9. The process of claim 8, wherein the second hydrodemetallization catalyst comprises a carrier and an active metal component loaded on the carrier, wherein the active metal component is at least one element selected from group VIB and/or group VIII metals, and the content of the active metal component is 6-18 wt% in terms of oxide based on the total amount of the second hydrodemetallization catalyst;

preferably, the second hydrodemetallization catalyst has an average pore diameter of 10-15nm and an average particle size of 0.8-4 mm.

10. The method of any of claims 1-9, wherein the heavy oil feedstock is a paraffinic heavy oil.

Technical Field

The invention relates to the field of heavy oil hydrotreating, in particular to a heavy oil hydrotreating method.

Background

The residual oil hydrotreating technology is to make residual oil and hydrogen gas produce chemical reaction under the conditions of high temperature, high pressure and catalyst existence, remove harmful impurities such as sulfur, nitrogen, heavy metal and the like in the residual oil, convert part of the residual oil into gasoline and diesel oil, and provide raw materials for catalytic cracking and other technologies to produce products with high added value.

The fixed bed residual oil hydrogenation technology has the advantages of mature process, simple operation, good product quality and the like, and is the most common residual oil hydrogenation technology in the industry at present. However, the fixed bed residual oil hydrogenation device has a short operation period, which is about 12-18 months generally at present. Reactor pressure drop is an important factor that limits the operating cycle of a fixed bed residue hydrogenation unit.

The paraffin-based crude oil is characterized by small relative density, high wax content, high condensation point, less sulfur and colloid content and more than 12.1 of characteristic factor of the paraffin-based crude oil. The gasoline produced by the crude oil has low octane number, and the diesel oil obtained by the crude oil has high cetane number and high viscosity index, and is suitable for production with high quality, high viscosity, poor colloid stability and the like. In a residual oil hydrogenation reaction device, as the paraffin-based heavy oil has large molecular weight and large viscosity, the liquid flow distribution is uneven, and the reaction effect is influenced; meanwhile, the gas circuit circulation is not smooth, so that the surge of the circulating compressor is easily caused. If the temperature of a reactor filled with the desulfurization and carbon residue removal catalyst is high, components such as colloid are converted excessively, asphaltene is easily separated out, pore channels of the rear desulfurization and carbon residue removal catalyst are blocked, the pressure drop of the reactor is increased, and the operation period of a residual oil hydrogenation device is greatly reduced.

The analysis result of the molecular structure of the paraffin-based heavy oil shows that the paraffin-based heavy oil has large molecular mass, more and longer aromatic hydrocarbon side chains and more aromatic hydrocarbon side chains which are easy to form steric hindrance, so that paraffin-based heavy oil molecules are difficult to enter a catalyst pore passage and are combined with an active site of a catalyst. In order to accelerate the hydro-conversion of paraffin-based heavy oil molecules, the temperature needs to be raised quickly, so that the catalyst deactivation rate is high.

In order to adapt to the molecular size of paraffin-based heavy oil, the pore channels of the catalyst are properly enlarged, and when the pore channels of the catalyst are too large, the specific surface area is greatly reduced, the active center of the loaded metal is reduced, and the activity of the catalyst is reduced. Therefore, the pore structure of the modified catalyst cannot solve the hydrogenation reaction problem of the paraffin-based heavy oil. In the prior art, a molecular catalyst is selected to enter the interior of residual oil macromolecules to directly react with the residual oil macromolecules.

CA2564359C discloses a residual oil hydrogenation method, in which a molecular catalyst is mixed with residual oil and then sequentially passed through a fixed bed reactor filled with the catalyst and a slurry bed reactor or an ebullating bed reactor, by which the residual oil conversion can be suitably increased, the pressure drop can be reduced, and the operation period can be prolonged. However, the process of the method disclosed by the method is complex, and a fixed bed reactor and a boiling bed reactor or a slurry bed reactor are required to be connected in series; in addition, the molecular catalyst has a large addition amount and high cost.

CN104650976A discloses a method for treating inferior heavy oil, which comprises the following steps: a. uniformly mixing an oil-soluble catalyst and a heavy oil raw material, and then sending the mixture into a hydrogenation reactor to carry out hydrogenation reaction in the presence of hydrogen; hydrogen is a two-stage hydrogenation process, the first stage oil-soluble catalyst is a naphthenic acid compound containing one or more metals of Mo, Ni and Co, and also contains an auxiliary agent of rare earth metal and alkali metal, wherein the auxiliary agent accounts for 0.1-5 wt% of the catalyst; then entering a second-stage hydrogenation process, wherein the hydrogenation catalyst is active metals Pt and Ni loaded on a porous silicon oxide carrier, the porous carrier presents bimodal distribution, the pore size is 1-5nm and 10-30nm, the content of Pt is 5-8 wt%, the content of Ni is 15-20 wt%, and the content of vanadium serving as an auxiliary agent is 10 wt% of the catalyst; the total adding amount of the oil-soluble catalyst is controlled to be 150-800 mu g/g; b. cutting the liquid product after hydrogenation reaction into light distillate oil and tail oil by a distillation device; c. b, performing conventional cyclone separation on the tail oil obtained in the step b to separate the tail oil into deslagged tail oil and tailings; d. c, feeding the deslag tail oil in the step c into a delayed coking device, and performing thermal cracking to obtain light distillate oil, dry gas and coke; the delayed coking conditions were: the temperature of the material entering the coke tower is 450-550 ℃, the pressure at the top of the coke tower is controlled to be 0.5-1.5 MPa, and the water injection amount is 1.0-4.0 m%; the roasting conditions of the tailings in the step e are as follows: the roasting temperature is 500-700 ℃, and the roasting time is 90-130 min; e. and c, roasting the tailings in the step c, and recovering the metal in the oil-soluble catalyst. The method disclosed by the method is not applied to a fixed bed reaction system, the operation is complex, and the adding amount of the oil-soluble catalyst is large.

Therefore, it is highly desirable to provide a heavy oil hydrotreating method with simple operation, good desulfurization, denitrification and carbon residue removal performance and long operation cycle.

Disclosure of Invention

The invention aims to overcome the defects that in the heavy oil hydrotreating process in the prior art, the desulfurization, denitrification and carbon residue removal performance of a catalyst is poor and the operation period of a device is short due to the fact that heavy oil molecules cannot enter a catalyst pore channel.

The invention provides a heavy oil hydrotreating method, which comprises the following steps: in the presence of hydrogen, the reaction mixture is,

(1) contacting a heavy oil raw material with a hydrogenation protection catalyst to obtain a first material;

(2) contacting the first material with a first hydrodemetallization catalyst to obtain a second material;

(3) contacting the second material with a hydrodesulfurization catalyst to obtain a third material;

the method further includes mixing an oil soluble catalyst into the first material and/or the second material.

Preferably, the second material is admixed with an oil-soluble catalyst in an amount of from 10 to 150. mu.g/g, preferably from 20 to 80. mu.g/g, more preferably from 20 to 60. mu.g/g, based on the total weight of the second material.

According to the method provided by the invention, the heavy oil raw material sequentially reacts with the hydrogenation protection catalyst, the first hydrogenation demetalization catalyst and the hydrodesulfurization catalyst, and the oil-soluble catalyst is mixed into the first material obtained by reacting the heavy oil raw material with the hydrogenation protection catalyst and/or the second material obtained by reacting the heavy oil raw material with the first hydrogenation demetalization catalyst. In addition, the method provided by the invention can achieve the effects by using a small amount of oil-soluble catalyst, and the production cost is reduced. In addition, the method provided by the invention is simple and convenient to operate and easy to implement.

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.

The invention provides a heavy oil hydrotreating method, which comprises the following steps: in the presence of hydrogen, the reaction mixture is,

(1) contacting a heavy oil raw material with a hydrogenation protection catalyst to obtain a first material;

(2) contacting the first material with a first hydrodemetallization catalyst to obtain a second material;

(3) contacting the second material with a hydrodesulfurization catalyst to obtain a third material;

the method further includes mixing an oil soluble catalyst into the first material and/or the second material.

The method provided by the invention can mix the oil-soluble catalyst into the first material, can mix the oil-soluble catalyst into the second material, and can mix the oil-soluble catalyst into the first material and/or the second material simultaneously. According to the method, the oil-soluble catalyst is mixed into the first material and/or the second material instead of being introduced into the heavy oil raw material, and by adopting the method, the using amount of the oil-soluble catalyst is small, the hydrodesulfurization, denitrification and carbon residue removal activity of the heavy oil hydrotreating method is higher, and the running period of the device is longer.

According to a preferred embodiment of the present invention, when the oil-soluble catalyst is mixed into the first material, the oil-soluble catalyst is added in an amount of 10 to 200. mu.g/g, preferably 20 to 100. mu.g/g, and more preferably 30 to 70. mu.g/g, based on the total weight of the first material; when the oil-soluble catalyst is mixed into the second material, the amount of the oil-soluble catalyst added is 10 to 150. mu.g/g, preferably 20 to 80. mu.g/g, and more preferably 20 to 60. mu.g/g, based on the total weight of the second material.

According to the method provided by the invention, when the oil-soluble catalyst is mixed into the first material and the oil-soluble catalyst is mixed into the second material, the total amount of the oil-soluble catalyst is preferably 10-200 mug/g, preferably 20-100 mug/g, and more preferably 30-70 mug/g based on the total weight of the first material. The present invention is not particularly limited in the amount of the oil-soluble catalyst added to the first material and the oil-soluble catalyst added to the second material as long as the total amount added is within the above range, and preferably, the amount of the oil-soluble catalyst added to the second material is larger than the amount of the oil-soluble catalyst added to the first material.

According to a preferred embodiment of the invention, an oil-soluble catalyst is mixed into the second material. In the research process, the inventor of the invention finds that the amount of the oil-soluble catalyst used can be smaller and the obtained effect is better when the oil-soluble catalyst is mixed into the second material than when the oil-soluble catalyst is mixed into the first material.

In the present invention, the oil-soluble catalyst is preferably at least one selected from the group consisting of a group VIB and/or group VIII metal-containing polycarbonyl compound, a naphthenate compound, an isooctoate compound, and a porphyrin-based chelate, and more preferably at least one selected from the group consisting of a group VIB and/or group VIII metal-containing polycarbonyl compound, a naphthenate compound, and an isooctanoate compound. The polycarbonyl compound may be a pentahydroxy compound or a hexahydroxy compound. The group VIB metal may be at least one of Fe, Co, and Ni, and the group VIII metal may be Mo.

According to a preferred embodiment of the present invention, the oil-soluble catalyst is selected from at least one of molybdenum naphthenate, iron naphthenate, molybdenum isooctanoate, molybdenum hexacarbonyl, vanadium naphthenate, iron pentacarbonyl and nickel tetraphenylporphyrin, further preferably is molybdenum isooctanoate and/or iron naphthenate, and most preferably is molybdenum isooctanoate.

According to a preferred embodiment of the present invention, the group VIB and/or group VIII metals are present in an amount of 8 to 40 wt.%, preferably 10 to 35 wt.%, calculated as metallic elements, based on the total amount of the oil-soluble catalyst.

In the present invention, the oil-soluble catalyst may be obtained commercially or by self-preparation, and the present invention is not particularly limited thereto.

The method provided by the invention can be carried out in a heavy oil hydrogenation device, and a hydrogenation protection catalyst, a first hydrogenation demetalization catalyst and a hydrogenation desulfurization catalyst are sequentially filled in the heavy oil hydrogenation device along the material flow direction. The heavy oil hydrogenation unit is preferably a fixed bed hydrogenation unit. The catalyst of the present invention may be loaded in the same fixed bed hydrogenation apparatus, or may be loaded in a plurality of different fixed bed hydrogenation apparatuses connected in series, and the number of the fixed bed hydrogenation apparatuses is not particularly limited as long as the catalyst is loaded in a manner required by the present invention. Preferably, the hydrogenation protection catalyst and the first hydrodemetallization catalyst are packed in the same fixed bed hydrogenation unit, and the hydrodesulfurization catalyst is packed in another fixed bed hydrogenation unit connected in series with the fixed bed hydrogenation unit.

According to a preferred embodiment, the loading of the hydrogenation protection catalyst is from 1 to 20% by volume, the loading of the first hydrodemetallization catalyst is from 10 to 70% by volume and the loading of the hydrodesulfurization catalyst is from 10 to 70% by volume, based on the total volume of the loaded catalyst;

according to another preferred embodiment, the loading of the hydrogenation protection catalyst is from 2 to 15% by volume, the loading of the first hydrodemetallization catalyst is from 30 to 70% by volume and the loading of the hydrodesulfurization catalyst is from 20 to 60% by volume, based on the total volume of the loaded catalyst. The inventors of the present invention have found that when the catalyst is packed in the packing volume of the preferred embodiment, the heavy oil hydrotreating method of the present invention can optimize the mass transfer of the heavy oil feedstock and convert more of the macromolecular asphaltenes and other substances therein when used for the hydrogenation of the heavy oil feedstock, thereby extending the operation cycle of the apparatus.

Preferably, the hydrogenation protection catalyst, the first hydrodemetallization catalyst and the hydrodesulfurization catalyst each independently comprise a carrier and an active metal component loaded on the carrier, wherein the active metal component is at least one of group VIB and/or group VIII metal elements. More preferably, the active metal component is any one or more of nickel-tungsten, nickel-tungsten-cobalt, nickel-molybdenum and cobalt-molybdenum combinations.

The carrier in the hydrogenation protection catalyst, the first hydrogenation demetallization catalyst and the hydrogenation desulfurization catalyst can be respectively and independently selected from at least one of alumina, silica and titania. At least one element such as boron, germanium, zirconium, phosphorus, chlorine or fluorine can be added into the carrier for modification.

The bulk density of the hydrogenation protection catalyst, the first hydrogenation demetalization catalyst and the hydrogenation desulfurization catalyst can be 0.3-1.2 g/cm³The average pore diameter can be 6-30 nm, and the specific surface area can be 50-400 m²/g。

The hydrogenation protection catalyst of the present invention may not contain an active metal component, and preferably, the hydrogenation protection catalyst contains a metal element selected from a group VIB and/or a group VIII as an active metal component, and the content of the active metal component is 1 to 12 wt% in terms of oxide based on the total amount of the hydrogenation protection catalyst. Preferably, the hydrogenation protection catalyst has an average pore diameter of 18 to 30nm and an average particle diameter of 1.3 to 50 mm.

In the present invention, the hydrogenation protection catalyst may be at least one of RG-series catalysts developed by the institute of petrochemical engineering science, china, for example.

According to the present invention, it is preferable that the content of the active metal component in the first hydrodemetallization catalyst is 6 to 15 wt% in terms of oxide, based on the total amount of the first hydrodemetallization catalyst. Preferably, the first hydrodemetallization catalyst has an average pore diameter of 10 to 20nm and an average particle diameter of 1.3 to 50 mm.

In the present invention, the first hydrodemetallization catalyst may be, for example, at least one of RDM-series catalysts and RUF-series catalysts developed by the chinese petrochemical science research institute.

According to the present invention, it is preferable that the active metal component is contained in the hydrodesulfurization catalyst in an amount of 8 to 25% by weight in terms of oxide based on the total amount of the hydrodesulfurization catalyst. Preferably, the hydrodesulfurization catalyst has an average pore diameter of 8 to 15nm and an average particle diameter of 0.6 to 2 mm.

In the present invention, the hydrodesulfurization catalyst may be, for example, at least one of an RMS series catalyst, an RCS series catalyst, and an RSN series catalyst developed by the chinese petrochemical science research institute.

In the present invention, the average particle diameter refers to an average maximum straight-line distance between two different points on the cross section of the particle, and when the particles of the hydrogenation protection catalyst, the first hydrodemetallization catalyst or the hydrodesulfurization catalyst are spherical, the average particle diameter refers to the diameter of the catalyst particles.

According to the invention, the process may be carried out under hydrotreating conditions, preferably comprising: the temperature is 320-450 ℃, the reaction pressure is 6-25MPa, and the liquid hourly space velocity is 0.1-1h^-1The volume ratio of hydrogen to oil is 250-1500; further preferably, the hydrotreating conditions include: the temperature is 350-420 ℃, the reaction pressure is 12-20MPa, and the liquid hourly space velocity is 0.2-0.4h^-1The volume ratio of hydrogen to oil is 300-1000.

According to a preferred embodiment of the invention, the process further comprises contacting said third material with a second hydrodemetallization catalyst. The inventors of the present invention have found that the use of such a preferred embodiment is more advantageous in increasing the operating cycle of a heavy oil hydrogenation apparatus.

According to the present invention, preferably, the method is carried out in a heavy oil hydrogenation device, wherein a hydrogenation protection catalyst, a first hydrogenation demetallization catalyst, a hydrodesulfurization catalyst and a second hydrogenation demetallization catalyst are sequentially loaded in the heavy oil hydrogenation device along the material flow direction, preferably, the loading amount of the hydrogenation protection catalyst is 1-20 vol%, the loading amount of the first hydrogenation demetallization catalyst is 5-60 vol%, the loading amount of the hydrodesulfurization catalyst is 5-60 vol%, and the loading amount of the second hydrogenation demetallization catalyst is 2-20 vol% based on the total volume of the loaded catalysts; further preferably, the loading amount of the hydrogenation protection catalyst is 2-15 vol%, the loading amount of the first hydrodemetallization catalyst is 25-60 vol%, the loading amount of the hydrodesulfurization catalyst is 15-50 vol%, and the loading amount of the second hydrodemetallization catalyst is 5-10 vol% based on the total volume of the loaded catalyst.

According to the method provided by the invention, the second hydrodemetallization catalyst and other catalysts can be filled in the same fixed bed hydrogenation device, or can be respectively filled in a plurality of different fixed bed hydrogenation devices which are connected in series. Preferably, the hydrogenation protection catalyst and the first hydrodemetallization catalyst are loaded in the same fixed bed hydrogenation unit, and the hydrodesulfurization catalyst and the second hydrodemetallization catalyst are loaded in another fixed bed hydrogenation unit connected in series with the fixed bed hydrogenation unit.

According to the invention, the second hydrodemetallization catalyst comprises a carrier and an active metal component loaded on the carrier, wherein the active metal component can be at least one selected from VIB group and/or VIII group metal elements, and the content of the active metal component can be 6-18 wt% in terms of oxide based on the total amount of the second hydrodemetallization catalyst.

According to a preferred embodiment of the invention, the second hydrodemetallization catalyst has an average pore diameter of 10 to 15nm and an average particle size of 0.8 to 4 mm.

The second hydrodemetallization catalyst may be the same as or different from the first hydrodemetallization catalyst. In the present invention, the "first" and "second" do not limit the hydrodemetallization catalyst, but are only for distinguishing the upstream and downstream of the hydrodesulfurization catalyst.

According to the invention, preferably, the loading of the second hydrodemetallization catalyst is smaller than the loading of the first hydrodemetallization catalyst. When the filling mode is adopted, the product obtained by the method has lower contents of carbon residue, sulfur and nitrogen and longer running period.

The method provided by the invention is suitable for processing various heavy raw oil, in particular for paraffin-based heavy oil, and preferably, the heavy oil raw material is paraffin-based heavy oil.

In the invention, the density of the paraffin-based heavy oil (components at the temperature of not less than 530 ℃) is lower, and is generally 970kg/m in the temperature of 900-³(ii) a The carbon residue content is below 12 wt%; a sulfur content of 1.5 wt% or less, and a sulfur content of 1.0 wt% or less in most cases; the nitrogen content is higher and is more than 0.2 weight percent; the saturated hydrocarbon content in the four component analysis was greater than 40 wt%.

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

In the following examples, various raw materials used were commercially available unless otherwise specified.

The catalysts used in the following are all industrial agents developed by China petrochemical engineering scientific research institute.

For theThe density, carbon residue content, S content and N content of the effluent were determined as described in table 1 below. Asphaltenes (C)₇Insolubles) conversion was determined as described in table 1 below.

TABLE 1

Analysis item	Analytical method	Standard of merit
			Density of	U-shaped vibration tube method	SH/T 0604-2000
Carbon residue number	Micro method	GB/T 17144-1997
			Residual oil asphaltenes	N-heptane-column chromatography	RIPP 10-1990
Content of S element	X-ray fluorescence spectrometry	GB/T 17040-2008
			Content of N element	Boat sample introduction chemiluminescence method	SH/T 0704-2010