CN109705898B

CN109705898B - Process for hydrotreating residua feedstocks

Info

Publication number: CN109705898B
Application number: CN201711012504.5A
Authority: CN
Inventors: 邵志才; 施瑢; 邓中活; 胡大为; 戴立顺; 聂红; 杨清河; 刘涛; 孙淑玲; 聂鑫鹏; 任亮; 赵宁
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2017-10-26
Filing date: 2017-10-26
Publication date: 2021-03-12
Anticipated expiration: 2037-10-26
Also published as: CN109705898A

Abstract

The invention relates to the field of residual oil hydrogenation, and discloses a residual oil raw material hydrotreating method, which is carried out in a hydrogenation device comprising a protection reaction zone and a fixed bed hydrogenation reaction zone, wherein the protection reaction zone at least comprises two protection reactors, the fixed bed hydrogenation reaction zone at least comprises a fixed bed reactor, a reactor A and a reactor B are connected in parallel or in series, the reactor A and the reactor B which are connected in parallel or in series are connected in series with other reactors optionally existing in the protection reaction zone and the fixed bed reactor in the fixed bed hydrogenation reaction zone, a first material containing raw material residual oil is sequentially introduced into a rotation type reactor A and/or a reactor B and a subsequent fixed bed reactor for hydrogenation reaction, and one of the rotation type reactor A or the reactor B is cleaned. The method of the invention can eliminate the carbon deposit on the catalyst of the protective reactor on line, prolong the continuous operation period of the device and realize easy agent discharge.

Description

Process for hydrotreating residua feedstocks

Technical Field

The invention relates to the field of residual oil hydrogenation, in particular to a hydrotreatment method of a residual oil raw material.

Background

Along with the increasing weight change of crude oil, the variety of crude oil is increasing, and the requirement on the weight change of heavy oil products is also increasing.

"heavy oil" refers to hydrocarbons of high asphaltene content derived from topped crude oil, petroleum residuum, oil sands, bitumen, shale oil, liquefied coal, or reclaimed oil.

The hydrogenation process of heavy oil is a heavy oil deep processing technology, and is characterized by that in the presence of hydrogen gas and catalyst the heavy oils of residual oil, etc. are undergone the processes of hydrodesulfurization, hydrodenitrogenation, hydrodemetallization, residual carbon conversion and hydrocracking reaction, so that the obtained hydrogenated residual oil can be used as feed material for high-quality catalytic cracking to produce light oil product so as to attain the goal of maximally lightening residual oil and implement non-residual oil refinery.

To date, four process types have been developed for residuum hydrogenation: fixed beds, ebullated beds, slurry beds, and moving beds. Among the four process types, the fixed bed process is mature and easy to operate, and the equipment investment is relatively low; the product hydrogen content is increased more and the unconverted residue can be used as RFCC feed, which is the most industrially applicable of the four processes.

In the prior art, generally, a plurality of hydrogenation reactors are arranged to realize the hydrogenation treatment of heavy oil products.

The deactivation of the catalyst for hydrotreating residual oil is mainly due to two reasons: the metal deposition and the carbon deposition of the catalyst are deactivated. The deposition of sulfides of metals Ni and V can cause deactivation of the residuum hydrogenation catalyst when processing the residuum feedstock. Meanwhile, the same as the deactivation of the distillate oil hydrogenation catalyst, the carbon deposit on the catalyst is also an important factor for the deactivation of the catalyst. Polycyclic aromatic hydrocarbon substances including colloids and asphaltenes in the residual oil raw material are adsorbed on the surface of the catalyst and then condensed and coked to form carbon deposit, so that the catalyst is inactivated. Therefore, when processing residual oil raw materials with high asphaltene and colloid contents, carbon deposition on the catalyst is an important reason for catalyst deactivation.

In the residual oil hydrogenation process, in order to inhibit the precipitation of asphaltene on a catalyst and carbon deposition, high-aromaticity raw materials are mostly adopted in the prior art, and the precipitation of asphaltene in a residual oil raw material is inhibited by utilizing the physical principle of similarity and intermiscibility.

CN102876373A discloses a method for prolonging the operation period of a hydrotreatment device, in the steady-state deactivation stage of a hydrotreatment catalyst, the method cools a reactor, switches raw oil into cleaning oil, maintains a lower hydrogen-oil ratio, and flushes a catalyst bed layer with the maximum oil inlet amount; raising the temperature of a catalyst bed layer, injecting a certain proportion of scale inhibitor into the cleaning oil, and performing circulation operation until no solid coke particles exist in the oil generated at the bottom of the fractionating tower; and adjusting the temperature, and injecting a vulcanizing agent into the cleaning oil to carry out supplementary vulcanization on the catalyst, thereby improving the activity of the catalyst. By adopting the method, physical decoking is also taken as a main part, soft coke and polymers adsorbed on the catalyst are dissolved, the temperature of the device needs to be reduced, the time for cleaning and sulfur supplement is longer, and the device can not carry out normal production.

CN102816598A discloses a method for reducing carbon deposition of a carbon residue removing catalyst of a residual oil hydrotreater, which is characterized in that a feed inlet is added in front of a carbon residue removing agent bed layer of the residual oil hydrotreater, high-aromaticity catalytic cracking recycle oil with 1-30% of the weight of raw residual oil is introduced through the feed inlet, and the dissolving capacity of asphaltene gradually separated out from the raw oil is increased, so that the carbon deposition on the catalyst is reduced.

CN102816595A A combined process of hydrotreatment and catalytic cracking of catalytic cracking recycle oil on residual oil, which is characterized in that a feed inlet is respectively added before a demetallization bed layer, a desulfurizer bed layer and a carbon residue removing agent bed layer of a device, the recycle oil is introduced into one or more feed inlets, and the carbon deposition speed of a catalyst is delayed. However, the method mixes the recycle oil into the residual oil raw material and the reactant thereof, and residual oil hydrogenation inevitably generates carbon deposit, so that the carbon deposit effect on the catalyst of the elimination protection reactor is not obvious.

CN101037618A discloses a coking inhibitor, a preparation method and an application thereof, wherein the coking inhibitor is a hydro-upgrading product of one or more hydrocarbon mixtures selected from coal tar, ethylene tar, catalytic cracking cycle oil, catalytic cracking slurry oil, catalytic cracking heavy oil, catalytic cracking extract oil and coking wax oil, and is used for preventing, delaying and eliminating coking in relevant equipment and pipelines in petroleum refining and petrochemical processes. The inhibitor needs to be added into the working fluid, and has limited effect on eliminating carbon deposit.

Disclosure of Invention

The invention aims to overcome the defects of the prior art in methods for eliminating or inhibiting carbon deposition and provides a method for hydrotreating a residual oil raw material, which can eliminate carbon deposition on a protective reactor catalyst on line.

The research of the inventor of the invention finds that when oil with high aromaticity is introduced into a hydrogenation device together with residual oil raw materials under the pressure of residual oil hydrogenation reaction, although the method can dissolve asphaltene to remove the asphaltene, the method has a poor cleaning effect on carbon deposit on the catalyst in a protection reactor under serious carbon deposit conditions; however, the inventor of the present invention found in the research that when a highly aromatic oil product is fed alone (without the residual oil feedstock) and hydrogen gas are fed into a reactor containing a residual oil hydrogenation old catalyst for hydrogenation, the hard carbon on the old catalyst undergoes hydrogenation reaction, and due to the large molecular structure of the hard carbon, activated hydrogen cannot be directly obtained from the active center of the catalyst due to steric hindrance effect, but the hydrogen donor compound in the highly aromatic oil product can provide or transfer the activated hydrogen to the hard carbon in the absence of the residual oil feedstock, so as to promote the conversion of the hard carbon into soft carbon, and the soft carbon can be dissolved in the highly aromatic oil product and converted into the oil product through hydrogenation reaction. Based on this finding, the inventors have completed the technical solution of the present invention.

In order to achieve the above object, the present invention provides a method for hydrotreating a residual oil feedstock, which is performed in a hydrogenation apparatus comprising a guard reaction zone and a fixed-bed hydrogenation reaction zone, wherein the guard reaction zone comprises at least two guard reactors, namely a reactor a and a reactor B, and the fixed-bed hydrogenation reaction zone comprises at least one fixed-bed reactor, wherein the reactor a and the reactor B are connected in parallel or in series, and the reactor a and the reactor B connected in parallel or in series are connected in series with other reactors optionally present in the guard reaction zone and the fixed-bed reactor in the fixed-bed hydrogenation reaction zone, the method comprising:

(a) the reactor A and the reactor B are connected in parallel,

under the condition of hydrogenation reaction, a first material containing raw material residual oil is sequentially introduced into a protection reaction zone and a fixed bed hydrogenation reaction zone for hydrogenation reaction, and the flow direction of the first material is controlled so that the first material only enters any one of a reactor A and a reactor B which are connected in parallel;

cutting out a reactor, into which a material from upstream of the parallel-connected reactors is introduced, of the parallel-connected reactors of the guard reaction zone when the hydrogenation apparatus reaches any one of the following conditions, and introducing a second material containing hydrogen and a purge oil into the cut-out reactor to perform a hydro-purge treatment therein, and switching the material from upstream of the parallel-connected reactors so that the material, when entering the parallel-connected reactors of the guard reaction zone, enters another reactor, which is not cut out, of the parallel-connected reactors to perform a hydrogenation reaction; the reaction effluent from the reactor cut out enters a subsequent reactor together with the reaction effluent from another reactor not cut out; or

(b) The reactor A and the reactor B are connected in series,

under the condition of hydrogenation reaction, a first material containing raw material residual oil is sequentially introduced into a protection reaction zone and a fixed bed hydrogenation reaction zone for hydrogenation reaction, and the flow direction of the first material is controlled so that the first material sequentially enters a reactor A and a reactor B;

cutting out any one of the reactor A and the reactor B of the guard reaction zone when the hydrogenation apparatus reaches any one of the following conditions, and introducing a second material containing hydrogen and a cleaning oil into the cut-out reactor to perform a hydrocleaning process therein; and switching the material from the upstream of the reactor A to be introduced into the unswitched reactor of the reactor A and the reactor B together with the reaction effluent from the switched-out reactor for hydrogenation reaction and then to enter the subsequent reactor together;

the conditions to be achieved by the hydrogenation unit include any one of the following conditions:

(1) the hydrogenation device continuously operates for more than 15 days;

(2) the pressure drop in the reactor a or the reactor B reaches an upper pressure drop limit;

(3) hot spots appear on the catalyst in the reactor A or the reactor B, so that the radial temperature difference of the reactor is more than or equal to 5 ℃;

optionally, repeating said step (a) or said step (B) by alternately switching said reactor a and said reactor B in and out for said hydrogenation reaction and said hydroprocessmg treatment until said hydrogenation unit reaches a shutdown condition;

wherein the total aromatic hydrocarbon content in the cleaning oil is 50-95 wt%.

The method provided by the invention can eliminate the carbon deposit on the catalyst of the protective reactor on line and obviously prolong the continuous operation time of the residual oil hydrogenation device.

Drawings

FIG. 1 is a process flow diagram for processing a residuum feedstock in accordance with a preferred embodiment of the present invention;

figure 2 is a process flow diagram for processing a residuum feedstock in accordance with another preferred embodiment of the present invention.

Description of the reference numerals

11. Reactor A

12. Reactor B

2. First fixed bed reactor

3. Second fixed bed reactor

4. Third fixed bed reactor

5. Fourth fixed bed reactor

6. First material

7. The second material

01. 02, 03, 04, 05 and 06 are valves.

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.

As described above, the present invention provides a method for hydrotreating a residual oil feedstock, which is carried out in a hydrogenation apparatus comprising a guard reaction zone and a fixed-bed hydrogenation reaction zone, wherein the guard reaction zone comprises at least two guard reactors, namely a reactor a and a reactor B, and the fixed-bed hydrogenation reaction zone comprises at least one fixed-bed reactor, wherein the reactor a and the reactor B are connected in parallel or in series, and the reactor a and the reactor B connected in parallel or in series are connected in series with other reactors optionally present in the guard reaction zone and the fixed-bed reactor in the fixed-bed hydrogenation reaction zone, the method comprising:

(a) the reactor A and the reactor B are connected in parallel,

(b) The reactor A and the reactor B are connected in series,

(1) the hydrogenation device continuously operates for more than 15 days;

Preferably, the reactor a and the reactor B according to the present invention have the same dimensions and catalyst loading.

According to a preferred embodiment, the reactor A and the reactor B are connected in series, when the pressure drop in any one of the reactor A and the reactor B of the hydrogenation device reaches the upper pressure drop limit or a hot spot occurs in the catalyst in the reactor, so that the radial temperature difference of the reactor is more than or equal to 5 ℃, the reactor is cut out, and a second material containing hydrogen and cleaning oil is introduced into the cut-out reactor to carry out the hydrogenation cleaning treatment in the reactor; and the material from the upstream of the reactor A is switched to be introduced into the unswitched reactor of the reactor A and the reactor B together with the reaction effluent from the switched-out reactor for hydrogenation reaction, and then the material enters the subsequent reactor together.

Preferably, in the above preferred embodiment, when the cut-out reactor is subjected to the hydrotreating process, when the pressure drop in the cut-out reactor and the radial temperature difference in the reactor return to within preset values, the introduction of the second material into the cut-out reactor is stopped, and the reaction effluent in the uncut reactor is introduced into the cut-out reactor to undergo the hydrotreating reaction and then enters the subsequent reactor. When the cut-out reactor is subjected to the hydro-cleaning treatment, the reaction effluent in the uncut reactor is introduced into the cut-out reactor to perform the hydro-reaction, which means that the cut-out reactor is cut into the process flow of the hydrogenation device again.

In the present invention, no matter the connection mode of the reactor a and the reactor B is in series or in parallel, when any one of the reactors has a pressure drop reaching the upper limit of the pressure drop or a catalyst therein has a hot spot so that the radial temperature difference of the reactor is not less than 5 ℃, the reactor is preferably cut out to perform the aforementioned hydrocleaning treatment of the present invention.

According to another preferred embodiment, said reactor a is connected in parallel with said reactor B, and when the pressure drop in the cut-out reactor and the radial temperature difference in the reactor return to within preset values during the hydro-cleaning treatment of the cut-out reactor, the introduction of said second material into the cut-out reactor is stopped, and the cut-out reactor is optionally subjected to a discharge treatment or a change treatment.

The restoration of the radial temperature difference to the preset value within the preset value range according to the present invention can be confirmed by those skilled in the art according to the working condition, and there is no particular limitation thereto.

Preferably, in the process of the invention, the cut-out reactor a or reactor B is shut down on-line with the reactors of other normally process-produced hydrogenation units.

Preferably, the total aromatic hydrocarbon content in the cleaning oil is 80-90 wt%.

Preferably, the content of the bicyclic aromatic hydrocarbon in the cleaning oil is 30-80 wt%; more preferably 50 to 70 wt%.

Preferably, the cleaning oil is at least one selected from straight-run diesel oil, catalytic cracking cycle oil and catalytic cracking slurry oil, and more preferably the catalytic cracking slurry oil of the invention is catalytic cracking slurry oil with solid particles removed.

The catalytic cracking diesel oil can be used for diesel oil of various catalytic cracking processes, such as DCC, MIP, HSCC and the like.

The aforementioned second materials may be identical or different cleaning oils may be selected to form the second material within the scope of the selectable cleaning oils provided by the present invention.

Preferably, the upper pressure drop limit is 40-80% of the maximum design pressure drop of the corresponding reactor in the guard reaction zone; more preferably still, the first and second liquid crystal compositions are,

the upper pressure drop limit is 45-75% of the maximum design pressure drop of the corresponding reactor in the guard reaction zone.

Preferably, the radial temperature difference of the reactor is 15-40 ℃; more preferably 20 to 35 ℃.

Preferably, in order to further prolong the operation period of the device, the continuous operation time of the hydrogenation reaction before the reactor A and the reactor B are cut out for hydrogenation cleaning treatment is 1/8-1/2, preferably 1/4-1/3 of the continuous operation period of the hydrogenation device.

Preferably, in order to prolong the operation period of the device and facilitate the agent discharge or the agent change, the time of the reactor A and the reactor B which are cut out each time for carrying out the hydro-cleaning treatment is 1/16-1/4, and more preferably 1/8-1/6 of the continuous operation period of the hydrogenation device.

Preferably, the dosage weight ratio of the raw material residual oil in the first material to the cleaning oil in the second material is 10: (1-4.5).

According to a preferred embodiment, the first material further comprises a cleaning oil, and the cleaning oil in the first material is cut out to be introduced into the cut-out reactor for a hydro-cleaning process when the step (a) or the step (b) is performed.

According to the aforementioned preferred embodiment, preferably, when the pressure drop in the cut-out reactor and the radial temperature difference in the reactor are restored within the preset value ranges at the time of the hydro-cleaning treatment of the cut-out reactor, the introduction of the second material into the cut-out reactor is stopped, and the cleaning oil in the second material is switched back to the first material.

Preferably, the hydrogenation units before and after cutting out the reactor a or the reactor B in the protection reaction zone are residual oil hydrogenation process conditions, and the residual oil hydrogenation process conditions comprise: the hydrogen partial pressure is 5.0-22.0 MPa, the reaction temperature is 330-450 ℃, and the volume space velocity is0.1～3.0h^-1The volume ratio of hydrogen to oil is 350-2000.

Preferably, the conditions of the hydro-cleaning treatment in the reactor a or the reactor B in the protection reaction zone cut out include: the hydrogen partial pressure is 5.0-22.0 MPa, the reaction temperature is 300-400 ℃, the hydrogen-oil volume ratio is 50-300, and the volume space velocity is 1.0-3.0 times of the volume space velocity of the residual oil hydrogenation process conditions.

Preferably, the number of the fixed bed reactors connected in series is 1-6. For example, the number of the fixed bed reactors connected in series is 2 to 6. In the present invention, when two or more fixed bed reactors are provided, the type of catalyst loading in each fixed bed reactor is not particularly limited, and the catalyst loading may be performed according to a conventional catalyst loading scheme in the art for residue hydrogenation, and a scheme of catalyst loading is exemplified in the example section of the present invention, and those skilled in the art should not be construed as limiting the present invention.

According to a preferred embodiment, the cut-out condition of the hydro-cleaning treatment in the reactor A or the reactor B in the protection reaction zone is controlled so that the density reduction value of the cleaning oil after the hydro-cleaning treatment is 1 to 10kg/m³More preferably 3 to 8kg/m³。

Preferably, the hydrogenation device is filled with a hydrogenation protection catalyst, a hydrodemetallization catalyst, a hydrodesulfurization catalyst and a carbon residue hydroconversion catalyst. The carrier in the hydrogenation protection catalyst, the hydrogenation demetallization catalyst, the hydrogenation desulfurization catalyst and the carbon residue hydrogenation conversion catalyst is respectively and independently selected from at least one of alumina, silica and titania. More preferably, the support is a modified support obtained after modification with an element selected from the group consisting of boron, germanium, zirconium, phosphorus, chlorine, and fluorine.

Preferably, the active metal components in the hydrogenation protection catalyst, the hydrodemetallization catalyst, the hydrodesulfurization catalyst and the carbon residue hydroconversion catalyst are each independently at least one of non-noble metal elements selected from groups VIB and VIII; more preferably, the active metal components in the hydrogenation protection catalyst, the hydrodemetallization catalyst, the hydrodesulfurization catalyst and the carbon residue hydroconversion catalyst are each independently at least one combination of nickel-tungsten, nickel-tungsten-cobalt, nickel-molybdenum and cobalt-molybdenum.

The aforementioned catalysts of the present invention may be selected from commercial catalysts conventional in the art or prepared by conventional methods of the prior art.

The packing volume ratio of each kind of catalyst in the process of the present invention is not particularly limited, and may be a packing volume ratio of a catalyst conventionally used in hydrotreating residual oil in the art. One loading volume ratio for each catalyst is exemplified in the examples of the present invention, and those skilled in the art should not be construed as limiting the present invention.

Preferably, the feedstock residue is a vacuum residue and/or an atmospheric residue. More preferably, the total content of Fe and Ca elements in the raw residue is not higher than 10 ug/g.

Preferably, the colloidal stability factor of the first material is not greater than 2.0. The polymerization of asphaltenes in the raw residue was characterized by the change in conductivity in mass fraction of the raw residue during the addition of n-heptane, and the (n-heptane/residue) ratio at which asphaltene polymerization occurred was defined as the colloid stability factor.

Preferably, the guard reactor in the hydrogenation apparatus of the present invention comprises at least one of an upflow fixed bed reactor, a downflow fixed bed reactor and a countercurrent fixed bed reactor. The downflow type fixed bed reactor refers to a fixed bed reactor with material flow flowing from top to bottom; the upflow fixed bed reactor refers to a fixed bed reactor with material flow flowing from bottom to top; the counter-flow fixed bed reactor refers to a fixed bed reactor with liquid and gas flow directions opposite.

In the method of the present invention, the step of performing the hydrotreating process using the cleaning oil and the step of the hydrogenation reaction may be repeated a plurality of times. Further, when the hydrogen washing treatment and the hydrogenation reaction are repeatedly performed, the conditions of each washing treatment and each hydrogenation reaction and the kind of the used washing oil are not particularly limited, and are not always required to be the same for each time, and it is possible to extend the operation period of the apparatus and to easily remove the agent within the range defined in the present invention.

A preferred embodiment of the present invention for hydrotreating a residua feedstock (process flow) is described below in conjunction with FIG. 1:

reactor a11 was connected in parallel with the reactor B12,

when the device is started, the valve 01 and the valve 02 are opened, the valve 03 and the valve 04 are closed, the first material 6 enters the reactor A11, and then enters the first fixed bed reactor 2, the second fixed bed reactor 3, the third fixed bed reactor 4 and the fourth fixed bed reactor 5 in sequence. After the device runs for a period of time, switching treatment is carried out, the valve 03 and the valve 04 are opened, the valve 01 is closed, the first material 6 enters the reactor B12, and then enters the first fixed bed reactor 2, the second fixed bed reactor 3, the third fixed bed reactor 4 and the fourth fixed bed reactor 5 in sequence; the second feed 7 enters reactor a11 and the stream exiting reactor a11 enters the first fixed bed reactor 2. After a period of operation in reactor B12, the above operation was repeated, with reactor A11 and reactor B12 alternately introducing the first or second feed.

Another preferred embodiment is provided below in conjunction with FIG. 2 to illustrate the present invention resid feed hydrotreating process (process flow):

reactor a11 was connected in series with the reactor B12,

when the device is started, the valve 01, the valve 05 and the valve 04 are opened, the valve 03, the valve 06 and the valve 02 are closed, the first material 6 sequentially enters the reactor A11 and the reactor B12, and then sequentially enters the first fixed bed reactor 2, the second fixed bed reactor 3, the third fixed bed reactor 4 and the fourth fixed bed reactor 5. After the device runs for a period of time, switching treatment is carried out, the valve 03 is opened, the valve 01 is closed, the other valves are kept in the original state, the first material 6 enters the reactor B12 and then sequentially enters the first fixed bed reactor 2, the second fixed bed reactor 3, the third fixed bed reactor 4 and the fourth fixed bed reactor 5; second feed 7 entered reactor a11 and the stream exiting reactor a11 entered reactor B12 for a hydro-cleaning treatment. After the reactor A11 is operated for a period of time, the valve 06 and the valve 02 are opened, the valve 05 and the valve 04 are closed, and the material flow at the outlet of the reactor B12 enters the reactor A11 and then sequentially enters the first fixed bed reactor 2, the second fixed bed reactor 3, the third fixed bed reactor 4 and the fourth fixed bed reactor 5.

The operations are repeated, and the reactor A11 and the reactor B12 alternately introduce the first material and the second material into the technological process of the hydrogenation device after the first material and the second material are operated for a period of time.

The precondition for performing the switching operation process is one of the aforementioned conditions of the present invention, and the time standard for switching out and switching in is based on the aforementioned standard of the present invention.

In particular, the process (process flow) and system for hydrotreating a residual oil feedstock of the present invention are not limited to the forms shown in fig. 1 and 2, but should be in all ways encompassed by the foregoing technical solutions of the present invention, and those skilled in the art should not be construed as limiting the present invention.

The method provided by the invention also has the following specific advantages:

(1) after one of the protective reactors is cut off, the high aromatic oil product and a small amount of hydrogen are introduced into the protective reactor, and residual oil raw materials in the protective reactor can be replaced.

(2) After the catalyst in the protective reactor operates for a period of time, the carbon deposition amount is higher, a certain metal deposition amount is also provided, the activity is lower, and the reaction temperature rise is not too high even if high aromatic oil products are introduced.

(3) The method of the invention has no influence on the treatment capacity of the hydrogenation unit in the process flow.

(4) Because the device is still in operation after the protective reactor is cut out, the high-aromaticity oil product can be subjected to a carbon elimination reaction with carbon deposit on the catalyst after being introduced into the cut-out protective reactor, the carbon deposit on the catalyst is eliminated, the activity of the catalyst can be recovered, or the agent is easier to unload if the protective reactor needs to unload the agent.

The present invention will be described in detail below by way of examples. In the following examples, various raw materials used are commercially available without specific description.

The catalysts used below were all the catalysts of the residual oil hydrotreating series developed by the institute of petrochemical science and technology of petrochemical industry in China and produced by catalyst ChangLing division. Wherein RG series is hydrogenation protection catalyst, RDM series is hydrogenation demetalization catalyst, RMS series is hydrogenation desulfurization catalyst, and RCS is catalyst for hydrogenation conversion of carbon residue.

The properties of the feedstock residue, the cleaning oil and the mixed oil in examples 1 to 6 and comparative examples 1 to 4 are shown in table 1; the properties of the feedstock residue, the cleaning oil and the mixed oil in examples 7 to 9 and comparative examples 5 to 6 are shown in table 5.

Examples 1-3 and comparative examples 1-2 were both conducted on a pilot plant as shown in FIG. 1 (maximum design pressure drop of the reactor is 0.8MPa), and the type and amount of catalyst loading in the hydrogenation unit are shown in Table 2.

Examples 4 to 6 and comparative examples 3 to 4 were both carried out on a pilot plant as shown in FIG. 2 (maximum design pressure drop of the reactor is 0.8MPa), and the type of loading and the amount of loading of the catalyst in the hydrogenation unit are shown in Table 4.

Examples 7 to 9 and comparative examples 5 to 6 were each conducted on a pilot plant as shown in FIG. 1 (maximum design pressure drop of the reactor is 0.8MPa), and the kind of loading and the amount of loading of the catalyst in the hydrogenation apparatus are shown in Table 6.

Example 10 was conducted on a pilot plant as shown in fig. 1, with the type and amount of catalyst loading in the hydrogenation unit shown in table 2.

Example 11 was conducted on a pilot plant as shown in fig. 2, with the type and amount of catalyst loading in the hydrogenation unit shown in table 6.

In tables 2, 4 and 6, R1A represents the catalyst in reactor a11, R1B represents the catalyst in reactor B12, R2 represents the catalyst in the first fixed bed reactor, R3 represents the catalyst in the second fixed bed reactor, R4 represents the catalyst in the third fixed bed reactor, and R5 represents the catalyst in the fourth fixed bed reactor.

Example 1

The raw material residual oil and hydrogen sequentially enter a reactor A11 and a first fixed bed reactor 2-a fourth fixed bed reactor 5 for hydrogenation reaction, and the hydrogenation reaction conditions comprise: volume space velocity of 0.22h^-1The volume ratio of hydrogen to oil is 700:1, and the hydrogen partial pressure is 15.0 MPa.

The product properties after residual oil hydrotreatment are kept as follows by adjusting the reaction temperature in the whole operation period: the sulfur content is 0.25 wt%, the nitrogen content is 0.16 wt%, the carbon residue value is 3.28 wt%, and the heavy metal (Ni + V) is 10 mu g/g, so that the requirement of RFCC feeding is met.

After the device is continuously operated for 3 months, introducing a residual oil raw material into a reactor B12, introducing cleaning oil and a small amount of hydrogen into a reactor A11, and sequentially introducing reaction effluents of the reactor B12 and the reactor A11 into a subsequent first fixed bed reactor 2-a subsequent fourth fixed bed reactor 5. The reactor A11 was operated with cleaning oil for 3 months, and then the unloading agent was stopped, at which time the average reaction temperature of the reactor B12 and the first, second, third and fourth fixed

bed reactors

2, 3, 4 and 5 was 383 ℃, indicating that the catalysts were still active.

The weight ratio of the cleaning oil to the raw material residual oil is 28:78, the reaction conditions in reactor a11 when the purge oil was introduced were: the hydrogen partial pressure is 15.0MPa, the volume ratio of hydrogen to oil is 60, and the volume space velocity is 0.575h^-1The density reduction value of the cleaning oil is controlled to be 3kg/m by controlling the reaction temperature³。

Example 2

The raw material residual oil and hydrogen sequentially enter a reactor A11 and a first fixed bed reactor 2-a fourth fixed bed reactor 5 for hydrogenation reaction, and the hydrogenation reaction conditions comprise: volume space velocity of 0.25h^-1The volume ratio of hydrogen to oil is 700:1, and the hydrogen partial pressure is 15.0 MPa.

After the device is continuously operated for 4 months, introducing a residual oil raw material into a reactor B12, introducing cleaning oil and a small amount of hydrogen into a reactor A11, and sequentially introducing reaction effluents of the reactor B12 and the reactor A11 into a subsequent first fixed bed reactor 2-a subsequent fourth fixed bed reactor 5. The reactor A11 was operated with cleaning oil for 4 months, and then the unloading agent was stopped, at which time the average reaction temperature of the reactor B12 and the first fixed bed reactor 2, the second fixed bed reactor 3, the third fixed bed reactor 4, and the fourth fixed bed reactor 5 was 387 deg.C, indicating that the catalysts were still active.

The weight ratio of the purge oil to the feedstock residue was 28:78, and when the purge oil was introduced, the reaction conditions in reactor a11 were: the hydrogen partial pressure is 15.0MPa, the volume ratio of hydrogen to oil is 180, and the volume space velocity is 0.654h^-1The washing oil density reduction value is controlled to be 8kg/m by controlling the reaction temperature³。

Comparative example 1

After the device continuously operates for 3 months, the residual oil raw material is sequentially introduced into the reactor B12 and the subsequent first fixed bed reactors 2-fourth fixed bed reactors 5, and a small amount of hydrogen enters the reactor A11 to be purged for 400 hours, and then the agent is stopped and removed.

Example 3

The mixed oil and hydrogen sequentially enter a reactor A11 and a first fixed bed reactor 2-a fourth fixed bed reactor 5 for hydrogenation reaction, and the hydrogenation reaction conditions comprise: volume space velocity of 0.253h^-1The volume ratio of hydrogen to oil is 700:1, and the hydrogen partial pressure is 15.0 MPa.

The product properties after residual oil hydrotreatment are kept as follows by adjusting the reaction temperature in the whole operation period: the sulfur content is 0.22 wt%, the nitrogen content is 0.14 wt%, the carbon residue value is 3.00 wt%, and the heavy metal (Ni + V) is 7 mu g/g, so that the requirement of RFCC feeding is met.

After the device is continuously operated for 3 months, introducing residual oil raw materials in the mixed oil into a reactor B12, introducing a small amount of hydrogen and cleaning oil in the mixed oil into a reactor A11, and sequentially introducing reaction effluents of the reactor B12 and the reactor A11 into a subsequent first fixed bed reactor 2-a subsequent fourth fixed bed reactor 5. The reactor A11 was operated with cleaning oil for 3 months, and then the unloading agent was stopped, at which time the average reaction temperature of the reactor B12 and the first, second, third and fourth fixed

bed reactors

2, 3, 4 and 5 was 381 deg.C, indicating that the catalysts were still active.

When the purge oil was introduced, the reaction conditions in reactor a11 were: hydrogen partial pressure of 15.0MPa, hydrogen-oil volume ratio of 60, and volume space velocity of 0.240h^-1The density reduction value of the cleaning oil is controlled to be 3kg/m by controlling the reaction temperature³。

Comparative example 2

After the device is continuously operated for 3 months, the mixed oil is sequentially introduced into the reactor B12 and the subsequent first fixed bed reactors 2-fourth fixed bed reactors 5, and after a small amount of hydrogen enters the reactor A11 and is purged for 300 hours, the reactor is stopped and the agent is replaced.

Discussion of the results: the carbon deposit on the catalyst packed in the reactor A11 was analyzed after the shutdown of examples 1 to 3 and comparative examples 1 to 2, respectively, and the results of the analysis are shown in Table 3. As can be seen from Table 3, the carbon deposition in examples 1-3 is greatly reduced compared to the corresponding comparative ratio, which is favorable for the activity recovery of the catalyst in the reactor.

Example 4

The residual oil raw material and hydrogen sequentially enter a reactor A11, a reactor B12, a first fixed bed reactor 2, a second fixed bed reactor 3, a third fixed bed reactor 4 and a fourth fixed bed reactor 5 for hydrogenation reaction, and the hydrogenation reaction conditions comprise: volume space velocity of 0.195h^-1The volume ratio of hydrogen to oil is 700:1, and the hydrogen partial pressure is 15.0 MPa.

After the device continuously operates for 4 months, introducing a residual oil raw material and hydrogen into a reactor B12, and sequentially introducing the reaction effluent of the reactor B12 into a first fixed bed reactor 2, a second fixed bed reactor 3, a third fixed bed reactor 4 and a fourth fixed bed reactor 5; cleaning oil and a small amount of hydrogen enter a reactor A11, and reaction effluent enters a reactor B12 and subsequent reactors; and after the reactor A11 is pumped with cleaning oil and runs for 1 month, the cleaning oil is stopped to be fed in, the effluent of the reactor B12 is introduced into the reactor A1 and then sequentially fed into the first fixed bed reactor 2, the second fixed bed reactor 3, the third fixed bed reactor 4 and the fourth fixed bed reactor 5. At this time, the average reaction temperatures of the reactor a11 and the reactor B12 and the first fixed bed reactor 2, the second fixed bed reactor 3, the third fixed bed reactor 4, and the fourth fixed bed reactor 5 were 376 ℃.

The weight ratio of purge oil to resid feedstock was 28:78, and the reaction conditions in reactor a11 were: hydrogen partial pressure of 15.0MPa, hydrogen-oil volume ratio of 60, and volume space velocity of 0.399h^-1The density reduction value of the cleaning oil is controlled to be 3kg/m by controlling the reaction temperature³。

Example 5

The residual oil raw material and hydrogen sequentially enter a reactor A11, a reactor B12, a first fixed bed reactor 2, a second fixed bed reactor 3, a third fixed bed reactor 4 and a fourth fixed bed reactor 5 for hydrogenation reaction, and the hydrogenation reaction conditions comprise: volume spaceThe speed is 0.195h^-1The volume ratio of hydrogen to oil is 700:1, and the hydrogen partial pressure is 15.0 MPa.

After the device continuously operates for 6 months, introducing a residual oil raw material and hydrogen into a reactor B12, and sequentially introducing reaction effluents in a reactor B12 into a first fixed bed reactor 2, a second fixed bed reactor 3, a third fixed bed reactor 4 and a fourth fixed bed reactor 5; cleaning oil and a small amount of hydrogen enter a reactor A11, and the reaction effluent of the reactor A11 enters a reactor B12 and a subsequent reactor; and after the cleaning oil is introduced into the reactor A11 and the operation is carried out for 1.5 months, the cleaning oil is stopped to be fed in, the effluent of the reactor B12 is introduced into the reactor A1 and then enters the first fixed bed reactor 2, the second fixed bed reactor 3, the third fixed bed reactor 4 and the fourth fixed bed reactor 5. At this time, the average reaction temperatures of the reactor a11 and the reactor B12, and the first fixed bed reactor 2, the second fixed bed reactor 3, the third fixed bed reactor 4, and the fourth fixed bed reactor 5 were 378 ℃.

The weight ratio of purge oil to resid feedstock was 28:78, and the reaction conditions in reactor a11 were: hydrogen partial pressure of 15.0MPa, hydrogen-oil volume ratio of 180, and volume space velocity of 0.399h^-1The washing oil density reduction value is controlled to be 8kg/m by controlling the reaction temperature³。

Comparative example 3

The residual oil raw material and hydrogen sequentially enter a reactor A11, a reactor B12, a first fixed bed reactor 2, a second fixed bed reactor 3, a third fixed bed reactor 4 and a fourth fixed bed reactor 5. The hydrogenation unit operating conditions include: volume space velocity of 0.195h^-1The volume ratio of hydrogen to oil is 700:1, and the hydrogen partial pressure is 15.0 MPa.

After the apparatus was continuously operated for 5 months, the average reaction temperature of the reactor a11 and the reactor B12 and the first fixed bed reactor 2, the second fixed bed reactor 3, the third fixed bed reactor 4, and the fourth fixed bed reactor 5 at this time was 383 ℃.

Example 6

The mixed oil and hydrogen sequentially enter a reactor A11, a reactor B12, a first fixed bed reactor 2, a second fixed bed reactor 3, a third fixed bed reactor 4 and a fourth fixed bed reactor 5 for hydrogenation reaction, and the hydrogenation reaction conditions comprise: volume space velocity of 0.224h^-1The volume ratio of hydrogen to oil is 700:1, and the hydrogen partial pressure is 15.0 MPa.

After the device continuously operates for 4 months, introducing a residual oil raw material in the mixed oil into a reactor B12, and sequentially introducing a reaction effluent of the reactor B12 into a first fixed bed reactor 2, a second fixed bed reactor 3, a third fixed bed reactor 4 and a fourth fixed bed reactor 5; a small amount of hydrogen and cleaning oil in the mixed oil enter a reactor A11, and the reaction effluent of the reactor A11 enters a reactor B12; and after the reactor A11 is pumped with cleaning oil and runs for 1 month, the cleaning oil is stopped to be fed, the cleaning oil and the residual oil raw material are introduced into the reactor B12, the effluent of the reactor B12 enters the reactor A11, and then enters the first fixed bed reactor 2, the second fixed bed reactor 3, the third fixed bed reactor 4 and the fourth fixed bed reactor 5. At this time, the average reaction temperatures of the reactor a11 and the reactor B12 and the first fixed bed reactor 2, the second fixed bed reactor 3, the third fixed bed reactor 4, and the fourth fixed bed reactor 5 were 375 ℃.

When the purge oil was introduced, the reaction conditions in reactor a11 were: the hydrogen partial pressure is 15.0MPa, the volume ratio of hydrogen to oil is 60, and the volume space velocity is 0.166h^-1The density reduction value of the cleaning oil is controlled to be 3kg/m by controlling the reaction temperature³。

Comparative example 4

After the apparatus was continuously operated for 5 months, the average reaction temperature of the reactor a11 and the reactor B12 and the first fixed bed reactor 2, the second fixed bed reactor 3, the third fixed bed reactor 4, and the fourth fixed bed reactor 5 at this time was 381 ℃.

Discussion of the results: it can be seen from examples 4-6 that the average reaction temperature of the catalyst was lower by the method of the present invention compared to comparative examples 3-4, indicating that the carbon deposit on the catalyst in the protective reactor is subjected to a decarburizing reaction and the catalytic activity of the catalyst in the protective reactor is restored.

Example 7

The residual oil raw material and hydrogen sequentially enter a reactor A11 and a first fixed bed reactor 2-a fourth fixed bed reactor 5, and the operation conditions of the hydrogenation device comprise: volume space velocity of 0.22h^-1The volume ratio of hydrogen to oil is 700:1, and the hydrogen partial pressure is 15.0 MPa. When the apparatus was started, the pressure drop in reactor A11 was 0.12 MPa.

The product properties after residual oil hydrotreatment are kept as follows by adjusting the reaction temperature in the whole operation period: the sulfur content is 0.12 wt%, the nitrogen content is 0.35 wt%, the carbon residue value is 5.8 wt%, and the heavy metal (Ni + V) is 15 mu g/g, so that the requirement of RFCC feeding is met.

After the device continuously runs for 6000h, the pressure drop of the reactor A11 is increased to 0.7MPa, the residual oil raw material is introduced into the reactor B12, the cleaning oil and a small amount of hydrogen enter the reactor A11, and the reaction effluents of the reactor B12 and the reactor A11 enter the subsequent first fixed bed reactors 2-5. After 400 hours of operation with the purge oil in reactor A11, the purge oil was removed and reactor A11 was shut down.

The weight ratio of the cleaning oil to the residual oil raw material is 28:78, the reaction conditions in reactor a11 when the purge oil was introduced were: hydrogen partial pressure of 15.0MPa, hydrogen-oil volume ratio of 60, and volume space velocity of 0.599h^-1The density reduction value of the cleaning oil is controlled to be 3kg/m by controlling the reaction temperature³。

Example 8

After the device continuously runs for 6000h, the pressure drop of the reactor A11 is increased to 0.7MPa, the residual oil raw material is introduced into the reactor B12, the cleaning oil and a small amount of hydrogen enter the reactor A11, and the reaction effluents of the reactor B12 and the reactor A11 enter the subsequent first fixed bed reactors 2-5. After the reactor A11 was run for 800 hours with purge oil, the purge oil was removed and the reactor A11 was shut down and replaced with a reagent.

The weight ratio of purge oil to resid feedstock was 8:92, and when purge oil was introduced, the reaction conditions in reactor a11 were: hydrogen partial pressure of 15.0MPa, hydrogen-oil volume ratio of 180, and volume space velocity of 0.146h^-1The washing oil density reduction value is controlled to be 8kg/m by controlling the reaction temperature³。

Comparative example 5

After the device continuously runs for 6000h, the pressure drop of the reactor A11 is increased to 0.7MPa, the residual oil raw material is introduced into the reactor B12, a small amount of hydrogen enters the reactor A11 and is purged for 400 hours, and then the agent is stopped and replaced.

Example 9

The mixed oil and hydrogen sequentially enter a reactor A11 and first to fourth fixed bed reactors 2 to 5, and the operation conditions of the hydrogenation device comprise: volume space velocity of 0.253h^-1The volume ratio of hydrogen to oil is 700:1, and the hydrogen partial pressure is 15.0 MPa. When the apparatus was started, the pressure drop in reactor A11 was 0.12 MPa.

The product properties after residual oil hydrotreatment are kept as follows by adjusting the reaction temperature in the whole operation period: the sulfur content is 0.11 weight percent, the nitrogen content is 0.34 weight percent, the carbon residue value is 5.6 weight percent, and the heavy metal (Ni + V) is 14 mu g/g, so that the requirement of RFCC feeding is met.

After the device continuously operates for 6000h, the pressure drop of the reactor A11 is increased to 0.7MPa, the residual oil raw material in the mixed oil is introduced into the reactor B12, a small amount of hydrogen and the cleaning oil in the mixed oil enter the reactor A11, and the reaction effluent of the reactor B12 and the reaction effluent of the reactor A11 enter the subsequent first fixed bed reactors 2 to the fourth fixed bed reactor 5. After running reactor a11 for 300 hours with purge oil, the purge oil was cut off and introduced into reactor B12 along with the residuum feedstock, and reactor a11 was shut down for agent changes.

When the purge oil was introduced, the reaction conditions in reactor a11 were: hydrogen partial pressure 15.0, hydrogen-oil volume ratio 60, volume space velocity 0.384h^-1The density reduction value of the cleaning oil is controlled to be 3kg/m by controlling the reaction temperature³。

Comparative example 6

The mixed oil and hydrogen sequentially enter a reactor A11 and first to fourth fixed bed reactors 2 to 5, and the operation conditions of the hydrogenation device comprise: volume space velocity of 0.253h^-1Hydrogen oil bodyThe volume ratio is 700:1, and the hydrogen partial pressure is 15.0 MPa. When the apparatus was started, the pressure drop in reactor A11 was 0.12 MPa.

After the device is continuously operated for 6000h, the pressure drop of the reactor A11 is increased to 0.7MPa, the mixed oil is introduced into the reactor B12, a small amount of hydrogen enters the reactor A11 and is purged for 300 hours, and the reactor A11 is shut down and the agent is replaced.

Discussion of the results: the carbon deposits on the catalyst packed in reactor A11 were analyzed after the shutdowns of examples 7-9 and comparative examples 5-6, respectively, and the results of the analyses are shown in Table 7. It can be seen from Table 7 that the carbon deposition in examples 7-9 is greatly reduced compared to the corresponding comparative examples, facilitating the removal of the catalyst from the reactor.

Example 10

Residual oil raw materials with the properties shown in the table 1 and hydrogen sequentially enter a reactor A11 and a first fixed bed reactor 2-a fourth fixed bed reactor 5 for hydrogenation reaction, and the hydrogenation reaction conditions comprise: the volume space velocity is 0.20h^-1The volume ratio of hydrogen to oil is 700:1, the hydrogen partial pressure is 15.0 MPa.

The product properties after residual oil hydrotreatment are kept as follows by adjusting the reaction temperature in the whole operation period: the sulfur content is 0.20 wt%, the nitrogen content is 0.10 wt%, the carbon residue value is 2.95 wt%, and the heavy metal (Ni + V) content is 5 mug/g, so that the requirement of subsequent RFCC feeding is met.

(1) After the hydrogenation device continuously operates for 4 months, introducing hydrogen and the residual oil raw material into a reactor B12, then sequentially entering a first fixed bed reactor 2-a fourth fixed bed reactor 5, and continuously processing the residual oil raw material for 4 months;

(2) simultaneously introducing a small amount of hydrogen and cleaning oil with the properties shown in the table 1 into a reactor A11, and sequentially feeding the material flow obtained in the reactor A11 into a first fixed bed reactor 2-a fourth fixed bed reactor 5 and operating for 4 months;

(3) then introducing the residual oil raw material into a reactor A11, then sequentially entering a first fixed bed reactor 2-a fourth fixed bed reactor 5, and continuously processing the residual oil raw material for 4 months;

(4) simultaneously introducing a small amount of hydrogen and cleaning oil with the properties shown in the table 1 into a reactor B12, and enabling the material flow obtained in the reactor B12 to enter a first fixed bed reactor 2-a fourth fixed bed reactor 5 and also to run for 4 months;

and (3) repeating the steps (1) to (4) for 5 times, wherein the device is operated for 24 months, the average temperature of the catalyst reaches 425 ℃, and the device is shut down.

The dosage weight ratio of the cleaning oil to the residual oil raw material is 28:78, the reaction conditions in reactor a11 or reactor B12 when introducing the purge oil are: the hydrogen partial pressure is 15.0MPa, and the volume ratio of hydrogen to oil is 60: 1, the volume space velocity is 0.523h^-1The washing oil density reduction value is controlled to be 4kg/m by controlling the reaction temperature³。

Example 11

The mixed oil and hydrogen with the properties shown in table 1 sequentially enter a reactor A11, a reactor B12, a first fixed bed reactor 2, a second fixed bed reactor 3, a third fixed bed reactor 4 and a fourth fixed bed reactor 5 for hydrogenation reaction, and the hydrogenation reaction conditions comprise: the volume space velocity is 0.23h^-1The volume ratio of hydrogen to oil is 700:1, the hydrogen partial pressure is 15.0 MPa.

The product properties after residual oil hydrotreatment are kept as follows by adjusting the reaction temperature in the whole operation period: the sulfur content is 0.22 wt%, the nitrogen content is 0.13 wt%, the carbon residue value is 3.15 wt%, and the heavy metal (Ni + V) content is 8 mug/g, so that the requirement of subsequent RFCC feeding is met.

(1) After the hydrogenation device continuously operates for 4 months, directly introducing residual oil raw materials and hydrogen in the mixed oil into a reactor B12, and then sequentially entering a first fixed bed reactor 2-a fourth fixed bed reactor 5;

(2) simultaneously introducing cleaning oil and a small amount of hydrogen in the mixed oil into a reactor A11, and sequentially introducing material flow obtained in a reactor A11 into a reactor B12 and first to fourth fixed bed reactors 2 to 5, and operating for 1 month in the way;

(3) introducing the material flow at the outlet of the reactor B12 into a reactor A11, sequentially introducing the material flow obtained in the reactor A11 into a first fixed bed reactor 2-a fourth fixed bed reactor 5, simultaneously cutting back the cleaning oil to enter a reactor B12 together with the residual oil raw material, and continuously processing the mixed oil for 3 months;

(4) then introducing hydrogen and residual oil raw materials in the mixed oil into a reactor A11 together, and sequentially feeding material flows obtained in the reactor A11 into a first fixed bed reactor 2-a fourth fixed bed reactor 5;

(5) simultaneously introducing cleaning oil in the mixed oil and a small amount of hydrogen into a reactor B12, and sequentially introducing material flow obtained in a reactor B12 into a reactor A11 and a first fixed bed reactor 2-a fourth fixed bed reactor 5, and operating for 1 month in the way;

(6) and introducing the outlet material flow of the reactor A11 into a reactor B12, sequentially introducing the material flow obtained in the reactor B12 into a first fixed bed reactor 2-a fourth fixed bed reactor 5, simultaneously cutting back the cleaning oil to enter a reactor A11 together with the residual oil raw material, and continuously processing the mixed oil for 3 months.

And (3) repeating the steps (1) to (6) for 5 times, wherein the device is operated for 24 months, the average temperature of the catalyst reaches 425 ℃, and the device is shut down.

The reaction conditions in reactor a11 or reactor B12 when the purge oil was introduced were: the hydrogen partial pressure is 15.0MPa, and the volume ratio of hydrogen to oil is 100: 1, volume space velocity of 0.246h^-1The washing oil density reduction value is controlled to be 5kg/m by controlling the reaction temperature³。

It is demonstrated from examples 10 and 11 that the process provided by the present invention allows the catalyst in the shift or displaceable guard reactor to be replaced without significant increase in the run length of the residuum hydrotreater.

TABLE 1

Raw oil	Raw residue oil	Cleaning oil	Mixing oil: m (residual oil): 87:13
				Density (20 ℃ C.)/(kg/m)³)	943.6	992.3	949.9
Viscosity (100 ℃ C.)/(mm)²/s)	39.9	-	23
				Carbon residue value/weight%	8.2	-	7.15
Sulfur content/weight%	1.73	1.25	1.67
				Nitrogen content/weight%	0.26	0.0644	0.24
Hydrogen content/weight%	11.31	9.20	11.04
				Metal (Ni + V) content/(μ g/g)	28.0	-	25.0
Metal (Fe + Ca) content/(μ g/g)	8.0	-	7.0
				Cetane index/(μ g/g)	-	17	-
Monocyclic aromatic content/weight%	-	7.5	-
				Bicyclic aromatic hydrocarbon content/weight%	-	63.0	-
Tricyclic aromatic content/weight%	-	14.9	-
				Total aromatic content/weight%	-	85.4	-

TABLE 2

Catalyst and process for preparing same	R1A/R1B	R2	R3	R4	R5
						RG-30B/ml	30	10
RDM-32/ml	30	90
						RDM-33B/ml			20
RMS-30/ml			80
						RCS-30/ml				100
RCS-31/ml					100

Table 3: average content of char on catalyst in reactor A11 (g/100g fresh catalyst)

Catalyst and process for preparing same	Example 1	Example 2	Example 3	Comparative example 1	Comparative example 2
						RG-30B	6	5	5	20	18
RDM-32	3	2	2	13	12

TABLE 4

Catalyst and process for preparing same	R1A/R1B	R2	R3	R4	R5
						RG-30B/ml	40
RDM-32/ml	60	100
						RDM-33B/ml		20
RMS-30/ml			80
						RCS-30/ml			100
RCS-31/ml					100

TABLE 5

TABLE 6

Catalyst and process for preparing same	R1A/R1B	R2	R3	R4	R5
						RG-30B/ml	30
RDM-32/ml	30	100
						RDM-33B/ml		20
RMS-30/ml			80
						RCS-30/ml			100
RCS-31/ml					100

Table 7: average content of char on catalyst in reactor A11 (g/100g fresh catalyst)

Catalyst and process for preparing same	Example 7	Example 8	Example 9	Comparative example 5	Comparative example 6
						RG-30	14	12	8	36	32
RDM-32	8	6	3	25	21

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. A process for hydrotreating a residual oil feedstock, which is carried out in a hydrogenation apparatus comprising a guard reaction zone and a fixed-bed hydrogenation reaction zone, wherein the guard reaction zone comprises at least two guard reactors, namely a reactor a and a reactor B, and the fixed-bed hydrogenation reaction zone comprises at least one fixed-bed reactor, wherein the reactor a and the reactor B are connected in parallel or in series, and the reactor a and the reactor B connected in parallel or in series are connected in series with other reactors optionally present in the guard reaction zone and the fixed-bed reactor in the fixed-bed hydrogenation reaction zone, the process comprising:

(a) the reactor A and the reactor B are connected in parallel,

(b) The reactor A and the reactor B are connected in series,

(1) the hydrogenation device continuously operates for more than 15 days;

2. The method according to claim 1, wherein the reactor A and the reactor B are connected in series, when the pressure drop in any one of the reactor A and the reactor B of the hydrogenation device reaches the upper pressure drop limit or a hot spot occurs in a catalyst in the reactor, so that the radial temperature difference of the reactor is more than or equal to 5 ℃, the reactor is cut out, and a second material containing hydrogen and cleaning oil is introduced into the cut-out reactor to carry out the hydrogenation cleaning treatment in the reactor; and the material from the upstream of the reactor A is switched to be introduced into the unswitched reactor of the reactor A and the reactor B together with the reaction effluent from the switched-out reactor for hydrogenation reaction, and then the material enters the subsequent reactor together.

3. The method according to claim 2, wherein, when the pressure drop in the cut-out reactor and the radial temperature difference in the reactor are restored within the preset value range in the hydro-cleaning process of the cut-out reactor, the introduction of the second material into the cut-out reactor is stopped, and the reaction effluent in the uncut reactor is introduced into the cut-out reactor to perform the hydrogenation reaction and then enters the subsequent reactor.

4. The method of claim 1, wherein reactor a is connected in parallel with reactor B, and wherein the introduction of the second material into the cut-out reactor is stopped when the pressure drop in the cut-out reactor and the radial temperature difference in the reactor return to within preset values during the hydro-cleaning of the cut-out reactor, and the cut-out reactor is optionally subjected to a discharge treatment or a change treatment.

5. A process according to any one of claims 1 to 4, wherein the total aromatics content in the wash oil is from 80 to 90 wt%.

6. A process according to any one of claims 1 to 4, wherein the cleaning oil has a bicyclic aromatic content of 30 to 80 wt%.

7. A process as claimed in claim 6, wherein the bicyclic aromatic content of the wash oil is from 50 to 70 wt%.

8. The method of claim 1, wherein the wash oil is selected from at least one of straight-run diesel, catalytic cracking cycle oil, and catalytic cracking slurry oil.

9. The process of any of claims 1-4, wherein the upper pressure drop limit is 40 to 80% of the maximum design pressure drop of the corresponding reactor in the guard reaction zone.

10. The process of claim 9, wherein the upper pressure drop limit is 45-75% of the maximum design pressure drop for the corresponding reactor in the guard reaction zone.

11. The process according to any one of claims 1 to 4, wherein the radial temperature difference of the reactor is 15 to 40 ℃.

12. The process of claim 11, wherein the radial temperature difference of the reactor is 20 to 35 ℃.

13. The method of any one of claims 1 to 4, wherein the continuous operating time of the hydrogenation reaction before each cut-out of the reactor A and the reactor B for the hydrocleaning treatment is 1/8 to 1/2 of the continuous operating cycle of the hydrogenation apparatus.

14. The method of claim 13, wherein the continuous run time of the hydroprocessing reaction before each cut-out of reactor a and reactor B for hydrocleaning is 1/4-1/3 of the continuous run cycle of the hydroprocessing unit.

15. The method according to any one of claims 1 to 4, wherein the ratio of the amount by weight of the raw residue in the first material to the amount by weight of the wash oil in the second material is 10: (1-4.5).

16. The method according to claim 15, wherein the first material further contains a cleaning oil, and the cleaning oil in the first material is cut out to be introduced into the cut-out reactor for a hydro-cleaning process when the step (a) or the step (b) is performed.

17. The method of claim 16, wherein, when the pressure drop in the cut-out reactor and the radial temperature difference in the reactor return to within the preset values while the cut-out reactor is being subjected to the hydro-cleaning process, the introduction of the second material into the cut-out reactor is stopped and the cleaning oil in the second material is switched back into the first material.

18. The method of any of claims 1-4, wherein hydrogenation units both before and after cutting out reactor A or reactor B in the guard reaction zone are subjected to residuum hydrogenation process conditions comprising: the hydrogen partial pressure is 5.0-22.0 MPa, the reaction temperature is 330-450 ℃, and the volume space velocity is 0.1-3.0 h^-1The volume ratio of hydrogen to oil is 350-2000.

19. The method of claim 18, wherein the conditions of the cut-out hydro-cleaning process in reactor a or reactor B in the guard reaction zone comprise: the hydrogen partial pressure is 5.0-22.0 MPa, the reaction temperature is 300-400 ℃, the hydrogen-oil volume ratio is 50-300, and the volume space velocity is 1.0-3.0 times of the volume space velocity of the residual oil hydrogenation process conditions.

20. The method according to claim 19, wherein the conditions of the hydro-cleaning treatment in the reactor A or the reactor B in the cut-out protection reaction zone are controlled so that the density reduction value of the cleaning oil after the hydro-cleaning treatment is 1 to 10kg/m³。

21. The method according to claim 20, wherein the conditions of the hydro-cleaning treatment in the reactor a or reactor B in the cut-out protection reaction zone are controlled so that the density reduction value of the cleaning oil after the hydro-cleaning treatment is 3 to 8kg/m³。

22. The method of claim 1, wherein the hydrogenation apparatus is loaded with a hydrogenation protection catalyst, a hydrodemetallization catalyst, a hydrodesulfurization catalyst, and a carbon residue hydroconversion catalyst, and the support of each of the hydrogenation protection catalyst, the hydrodemetallization catalyst, the hydrodesulfurization catalyst, and the carbon residue hydroconversion catalyst is independently selected from at least one of alumina, silica, and titania.

23. The method according to claim 22, wherein the support is a modified support obtained after modification with an element selected from boron, germanium, zirconium, phosphorus, chlorine, and fluorine.

24. The process of claim 22, wherein the active metal component of the hydro-protective catalyst, hydrodemetallization catalyst, hydrodesulfurization catalyst, and carbon residue hydroconversion catalyst is each independently at least one of a non-noble metal element selected from group VIB and group VIII.

25. The process of claim 24, wherein the active metal components in the hydro-protective catalyst, hydrodemetallization catalyst, hydrodesulfurization catalyst, and carbon residue hydroconversion catalyst are each independently at least one combination of nickel-tungsten, nickel-tungsten-cobalt, nickel-molybdenum, and cobalt-molybdenum.

26. A process according to claim 1 in which the feed resid is a vacuum resid and/or an atmospheric resid.

27. The method of claim 1, wherein the first material has a colloidal stability factor of no greater than 2.0.