TW201601838A - Method for regenerating and utilizing heavy-oil desulfurization catalyst - Google Patents

Abstract

The present invention addresses the problem of providing a method for regenerating and utilizing a heavy-oil desulfurization catalyst, the method making it possible to more effectively reutilize a spent catalyst. This method is a method for regenerating and utilizing a catalyst used in one hydrodesulfurization device in which a feed heavy oil is introduced into the catalyst-packed reaction column from the column top and the hydrodesulfurized feed heavy oil is discharged from the bottom of the reaction column. The method is characterized by comprising: a step in which a heavy-oil desulfurization catalyst is packed into the reaction column so as to be separated and disposed in two or more stages, and the heavy-oil desulfurization catalyst in the m-th stage from the column top in the reaction column (m is an integer of 2 or larger) and the heavy-oil desulfurization catalyst in the n-th stage from the column top in the reaction column (n is an integer satisfying n < m) are withdrawn; a step in which the heavy-oil desulfurization catalyst withdrawn from the m-th stage from the column top in the reaction column is regenerated; and a step in which the regenerated heavy-oil desulfurization catalyst is packed into the n-th stage from the column top in the reaction column, and either a catalyst which was withdrawn from a stage located further apart from the reaction column top than the m-th stage and which has been regenerated or a fresh catalyst is packed into the m-th stage.

Description

Recycling method for heavy oil desulfurization catalyst

The present invention relates to a method for recycling and utilizing a heavy oil desulfurization catalyst used in a hydrodesulfurization treatment of heavy oil.

There are a number of steps for purifying various fractions by hydrodesulfurization treatment during petroleum purification, and various catalysts for this have been developed. The catalyst includes a desulfurization and denitrification catalyst for petroleum brain, kerosene and light oil, a desulfurization and denitrification catalyst for heavy light oil, a decomposition catalyst, and a desulfurization and denitrification catalyst for residual oil and heavy oil. Among them, the catalyst used in the hydrodesulfurization treatment of petroleum brain, kerosene, and gas oil having a low boiling point and almost no metal impurity such as vanadium is less deteriorated by use.

The catalyst used in the hydrodesulfurization treatment of petroleum brain, kerosene, and gas oil does not deteriorate due to metal impurities such as vanadium, and the deterioration of the catalyst is caused by a small amount of carbonaceous accumulation. Therefore, if carbon is removed from the catalyst by combustion, the catalyst can be reused. Further, regarding the removal of carbonaceous material, since the carbon mass on the catalyst is small, it is not necessary to strictly control the combustion, that is, the catalyst can be regenerated. Further, in the catalyst to be used, there is also a degree of deterioration, and such a catalyst can be directly reused without being subjected to regeneration treatment.

Recently, a hydrodesulfurization treatment catalyst for heavy light oil, decompression light oil, and the like has been regenerated and reused, and a regeneration method and a reuse method of the catalyst have been established. For example, the hydrogenation decomposition catalyst used in the heavy light oil hydrogenation decomposition process and the hydrogenation denitrification catalyst used for the pretreatment thereof are regenerated and reused by hydrogen activation or oxygen activation. Since the catalyst used for the hydrodesulfurization treatment of the distillate oil is used in the feedstock oil having less metal impurities, the metal such as vanadium is less deposited on the catalyst. Further, the amount of carbon deposited on the catalyst is also small, and the carbonaceous material deposited on the catalyst is easily burned. Therefore, the surface of the catalyst does not rapidly become a high temperature by combustion regeneration. Therefore, the pore structure of the catalyst and the supporting state of the active metal caused by the regeneration treatment are small, and can be reused for heavy light oil and vacuum oil. In the treatment of the distillate oil (see Non-Patent Document 1).

However, the heavy oil containing a fraction having a high boiling point or a fraction which cannot be distilled contains a large amount of easily carbonizable components such as asphaltene components and metal impurities, and is used in a catalyst used after hydrodesulfurization treatment. Stacked a lot of carbon and metal components. Since it is not possible to simply remove the carbonaceous material from the catalyst which has been used for the simultaneous accumulation of carbonaceous materials and metal components, it is necessary to remove the carbonaceous material at a high combustion temperature. Therefore, the pore structure of the catalyst and the change in the supporting state of the active metal due to the regeneration treatment are large, and the function of the catalyst after removing the carbonaceous material is remarkably lowered (see Non-Patent Document 2 and Non-Patent Document 3). Thereby, the catalyst used in the hydrodesulfurization treatment of heavy oil is disposed of without being reused.

However, in order to reduce waste and reduce catalyst costs, it is very important to regenerate the catalyst used in the hydrodesulfurization of heavy oil. And reuse. For example, a method for regenerating a heavy oil hydrotreating catalyst described in Patent Document 1 and a method for hydrodesulfurizing a heavy oil described in Patent Document 2 are known. According to the method for regenerating the heavy oil hydrotreating catalyst described in Patent Document 1, the catalyst deactivated by use in the hydrogenation purification treatment process of the heavy oil is subjected to regeneration treatment, and the pore volume, pore diameter, and The regenerated hydrotreated catalyst having a vanadium accumulation amount and a metal allowable amount calculated from the surface area per unit volume of a specific value can be reused for hydrogenation treatment of heavy oil. Further, according to the method for hydrodesulfurization of heavy oil described in Patent Document 2, the catalyst which is deactivated by use in a hydrotreating process such as heavy oil and which cannot be used can be regenerated, and can be effectively utilized.

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent No. 3,708,381

Patent Document 2: Japanese Patent No. 3527635

[Non-patent literature]

Non-Patent Document 1: Stadies in Surface and Catalysis, vol. 88, p199 (1994)

Non-Patent Document 2: Catal. Today, vol. 17, No. 4, P539 (1993)

Non-Patent Document 3: Catal. Rev. Sci. Eng., 33(3&4), P281 (1991)

However, in the method for regenerating the heavy oil hydrotreating catalyst described in Patent Document 1, the physical properties of the catalyst used as the raw material of the regenerated catalyst are related to the raw material or the operating conditions, and have a large influence on the regenerability. High equipment must not be used as a regenerative catalyst. Further, the method for hydrodesulfurization of heavy oil described in Patent Document 2 proposes only one regeneration method of one apparatus, and does not continuously and stably regenerate the method. Accordingly, it is an object of the present invention to provide a method for recycling a heavy oil desulfurization catalyst which can more effectively reuse a used catalyst.

As a result of active research by the present inventors, it has been found that even if it is used in the heavy oil hydrodesulfurization treatment and is deactivated and cannot be regenerated in the past, it can be used at a specific stage from the top side of the reaction column. Catalyst, thus completing the present invention. That is, the present invention is as follows.

[1] A method for recycling a heavy oil desulfurization catalyst, which is charged into a raw material heavy oil from a top side of a reaction column packed with a catalyst, and hydrodesulfurized from the bottom side of the reaction column A method for regenerating a catalyst used in a hydrodesulfurization apparatus for discharging heavy oil of a raw material, characterized in that the step of dividing a heavy oil desulfurization catalyst filled in the reaction column into a plurality of stages of 2 or more is carried out from the reaction tower From the top of the tower a step of the heavy oil desulfurization catalyst of the mth stage (m is an integer of 2 or more) and the heavy oil desulfurization catalyst of the nth stage (n satisfies an integer of n < m) from the top side of the reaction column, and the reaction from the reaction The step of regenerating the heavy oil desulfurization catalyst extracted from the m section of the top of the tower, and the re-sulfurized catalyst of the regenerated heavy oil is filled in the nth section from the top side of the reaction tower, and will be more than the mth section The step of filling or regenerating the catalyst or new catalyst away from the top of the aforementioned reaction column to the mth stage.

[2] The method for regenerating a heavy oil desulfurization catalyst according to the above [1], wherein the heavy oil desulfurization catalyst charged in the mth stage is regenerated and used in the nth stage is represented by the following formula (1) The metal tolerance MPr is larger than the metal tolerance MPr when the catalyst filled to the n+1th stage (only n+1<m) is regenerated and used in the same n+1th stage. MPr = (PV / 2Vv) × {8 × 10 ⁵ × (PD) ^1.3 } × (Sp / Vp) - (VA1 + VA2). . . (1)

In the formula (1), each symbol is expressed as follows,

PV: pore volume (m ³ /kg) for new catalyst

Vv: When 1% by mass of the vanadium deposited on the novel catalyst of it as 1kg of vanadium sulfide by volume ^{= 3.8 × 10 -6 (m 3} /% kg)

PD: average pore diameter (m) at the time of new catalyst

Sp: average external surface area (m ² ) of one particle in the case of a new catalyst

Vp: average volume of one particle (m ³ ) at the time of the new catalyst

VA1: Vanadium accumulation amount (% by mass) on the catalyst before re-supply to the hydrogenation desulfurization unit (new catalyst standard)

VA2: Vanadium accumulation amount (% by mass) expected to be accumulated in the same apparatus for reductive desulfurization.

[3] The method for recycling a heavy oil desulfurization catalyst according to the above [1] or [2], wherein each of the stages of the reaction column packed with the regenerated heavy oil desulfurization catalyst is represented by the above formula (1) The total amount of metal tolerance MPr is 0 or more, and the regenerated heavy oil desulfurization catalyst is filled into the reaction column.

[4] The method for recycling a heavy oil desulfurization catalyst according to the above [3], wherein the regenerated heavy oil desulfurization catalyst is filled in the reaction column so that the total amount of the metal allowable amount MPr is 1 or more and 5 or less.

According to the present invention, a method for recycling a heavy oil desulfurization catalyst which further utilizes the used catalyst more efficiently can be provided.

1‧‧‧First bed

2‧‧‧2nd bed

3‧‧‧3rd bed

4‧‧‧4th bed

10‧‧‧Hydrogenation desulfurization unit

12‧‧‧The top side of the tower

14‧‧‧ bottom side of the tower

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing an example of a reactor of the present invention.

Fig. 2 is a schematic view for explaining a downflow type fixed bed reactor used in an embodiment of the present invention.

The present invention relates to a catalyst for use in a hydrogenation desulfurization apparatus which discharges heavy oil from a top side of a reaction column packed with a catalyst and discharges heavy oil from a hydrogenation desulfurization raw material from a bottom side of a reaction tower in a device. Recycling method characterized by having a step of extracting a heavy oil desulfurization catalyst The step of regenerating the extracted heavy oil desulfurization catalyst and the step of filling the heavy oil desulfurization catalyst. Hereinafter, a method for recycling and utilizing the heavy oil desulfurization catalyst of the present invention will be described in detail with reference to Fig. 1 . BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view for explaining an example of a reactor of the present invention. Further, the reactor shown in Fig. 1 is, after all, only an example of the reactor of the present invention, and does not limit the present invention.

[Hydrogenation desulfurization device]

As shown in FIG. 1, the hydrogenation desulfurization apparatus 10 of the present invention is charged with a raw material heavy oil L from the top side 12 of a reaction column packed with a catalyst, and a hydrogenated desulfurized raw material heavy oil L is discharged from the bottom side 14 of the reaction tower. . Further, the catalyst packed in the reaction column is a heavy oil desulfurization catalyst, and the heavy oil desulfurization catalyst is divided into a plurality of stages of 2 or more.

In the hydrodesulfurization apparatus of the present invention, the heavy oil is subjected to desulfurization, denitrification, deoxidation, hydrogenation and decomposition of hydrocarbons by hydrodesulfurization treatment. Further, the hydrodesulfurization apparatus is not only hydrogenated and purified by desulfurization and denitrification, but also dehydrogenation and hydrodecomposition of asphaltenes. In view of this aspect, the hydrodesulfurization apparatus is used not only for the purpose of desulfurization of heavy oil, but also in combination with a residual oil purification process such as residual oil flow contact decomposition (RFCC), coking, and solvent removal. The heavy oil of the product obtained by the hydrodesulfurization apparatus is utilized as, for example, an RFCC raw material, a coking raw material, and a low sulfur product heavy oil.

Next, the hydrodesulfurization treatment by a hydrodesulfurization apparatus will be described. The hydrodesulfurization treatment carried out by the hydrodesulfurization apparatus is not limited as long as the heavy oil can be desulfurized. The hydrodesulfurization treatment by a hydrodesulfurization apparatus will be described by way of an example of a hydrodesulfurization treatment using a fixed bed reactor. Become hydrogenated The heavy oil of the sulfur-treated raw material contains residual components such as atmospheric residual oil and reduced-pressure residual oil. However, heavy oil does not include kerosene, light oil, and decompression light oil, etc., which are formed only from distillate oil. For example, the heavy oil contains 1% by mass or more of the sulfur component, 200 ppm by mass or more of the nitrogen component, 5% by mass or more of the residual carbon component, 5 ppm or more of vanadium, and 0.5% by mass or more of the asphaltene component. The heavy oil is exemplified by crude oil other than atmospheric residual oil, asphalt oil, thermal decomposition oil, tar sands oil, and the like. The heavy oil which is a raw material of the hydrodesulfurization treatment is not particularly limited as long as it is as described above, but it is preferred to use a normal pressure residual oil, a reduced pressure residual oil, a vacuum residue or a mixed oil of asphalt oil and decomposed light oil as hydrogenation. Raw material for desulfurization treatment.

The reaction temperature of the hydrodesulfurization treatment is preferably from 300 to 450 ° C, more preferably from 350 to 420 ° C, and even more preferably from 370 to 410 ° C. The partial pressure of hydrogen in the hydrodesulfurization treatment is preferably 7.0 to 25.0 MPa, more preferably 10.0 to 18.0 MPa. The liquid space velocity of the hydrodesulfurization treatment is preferably from 0.01 to 10 h ^-1 , more preferably from 0.1 to 5 h ^-1 , and even more preferably from 0.1 to 1 h ^-1 . The hydrogen/feedstock ratio of the hydrodesulfurization treatment is preferably from 500 to 2,500 Nm ³ /kl, more preferably from 700 to 2,000 Nm ³ /kl. Further, the adjustment of the sulfur content of the produced oil obtained by the hydrodesulfurization treatment and the content of the metal component (vanadium, nickel, etc.) can be carried out, for example, by appropriately adjusting the reaction temperature in the hydrodesulfurization treatment.

[heavy oil desulfurization catalyst]

The heavy oil desulfurization catalyst in the present invention is a catalyst for use in a hydrodesulfurization treatment of heavy oil at least once for a catalyst (including a sulfurized catalyst) which is usually used in desulfurization of heavy oil. Usually, carbon and vanadium are used Etc. attached to the catalyst. The heavy oil desulfurization catalyst is not particularly limited as long as it is a hydrodesulfurization treatment for heavy oil. For example, an alumina catalyst supporting molybdenum on an alumina support is used as a heavy oil desulfurization catalyst. In this case, cobalt or nickel is used as a co-catalyst.

The alumina support may also contain at least one of phosphorus, bismuth and boron. The content of at least one of phosphorus, bismuth and boron in the conversion to an oxide is preferably 30.0% by mass or less, more preferably 0.1 to 10.0% by mass, still more preferably 0.2 to 5.0% by mass. However, the content of at least one of phosphorus, cerium and boron in the catalyst is oxidized at a temperature of 400 ° C or higher, and the amount of reduction is not caused by heating, and the mass is %, and phosphorus, bismuth and boron are represented by mass%. At least one of the contents.

The molybdenum content in the heavy oil desulfurization catalyst is preferably from 0.1 to 25.0% by mass, more preferably from 0.2 to 8.0% by mass. Further, the content of cobalt or nickel in the heavy oil desulfurization catalyst is preferably from 0.1 to 10.0% by mass, more preferably from 0.2 to 8.0% by mass. In addition, the content of the metal component in the heavy oil desulfurization catalyst is oxidized at a temperature of 400 ° C or higher, and the amount of the oxide of the metal to be measured is expressed by mass% as the reference mass.

Heavy oil contains more asphaltenes and vanadium, so the heavy oil desulfurization catalyst used in the heavy oil desulfurization treatment will accumulate carbon components and vanadium. The carbon component is coated on the surface of the catalyst of the heavy oil desulfurization catalyst, so that the catalytic activity of the heavy oil desulfurization catalyst is lowered. However, the regeneration treatment such as solvent extraction and oxidative combustion treatment can remove the carbon component deposited on the heavy oil desulfurization catalyst and increase the catalytic activity of the heavy oil desulfurization catalyst. The content of carbon component in the used heavy oil desulfurization catalyst before regeneration treatment is preferably 10~70 The mass % is more preferably 0.2 to 8.0% by mass. When the content of the carbon component in the heavy oil desulfurization catalyst is more than 70% by mass, the catalyst activity cannot be sufficiently increased even after the regeneration treatment, and it is necessary to carry out the regeneration treatment at a high temperature in order to increase the catalyst activity, so that the catalyst strength may be lowered. Further, the content of the carbon component in the heavy oil desulfurization catalyst is determined by oxidation treatment at a temperature of 400 ° C or higher, reduction of the amount of carbon which is not caused by heating, and mass of the carbon component in the target catalyst by mass %.

The vanadium content in the heavy oil desulfurization catalyst used before the regeneration treatment is preferably 35 mass% or less, more preferably 20 mass% or less. When the vanadium content is more than 35% by mass, the catalyst activity cannot be sufficiently increased even after the regeneration treatment, and it is necessary to carry out the regeneration treatment at a high temperature in order to increase the catalyst activity, so that the catalyst strength may be lowered. Vanadium deposited on heavy oil desulfurization catalysts is generally not removed by regeneration.

The vanadium content of the used catalyst is almost unchanged before and after the regeneration treatment. Therefore, depending on the vanadium content in the used catalyst, the catalyst which can be used for regeneration and the catalyst which cannot be used even after regeneration can be discriminated before the regeneration treatment. Even if the catalyst which cannot be used for regeneration is wasted by the regeneration treatment, it is preferred to remove the catalyst which is known to be unusable even after regeneration, from the used catalyst before the regeneration treatment.

The catalyst used in the hydrodesulfurization treatment and the catalyst for performing the oxidation treatment for regenerative treatment, especially the combustion treatment, may have a catalyst structure during heating, and the pore structure of the catalyst and the supporting state of the active metal are changed by heating, so that the catalyst activity is lowered. The situation. As an index for evaluating these, there is a specific surface area of the catalyst or a pore volume. The specific surface area and pore volume of the catalyst are gradually reduced by the hydrodesulfurization treatment and the adhesion of impurities, and the regeneration treatment is easily reduced. The specific surface area and pore volume of the used heavy oil desulfurization catalyst are preferably 70% or more of the specific surface area and pore volume of the new catalyst. The heavy oil used the specific surface area of the desulfurization catalyst is preferably 60 ~ 220m ² / g, more preferably 100 ~ 200m ² / g. Further, the pore volume of the used heavy oil desulfurization catalyst is preferably from 0.3 to 1.2 cc/g, more preferably from 0.4 to 0.8 cc/g.

Further, the new catalyst is a catalyst which is produced as a catalyst and which is not used for the hydrodesulfurization treatment at a time. Further, the new catalyst also contains a catalyst which is used in a hydrodesulfurization treatment but is discontinued for a short period of time due to problems in the apparatus, etc., and is used again directly. That is, even if it is used for a short period of time without special revitalization treatment, without being extracted from the reactor and subjected to regeneration treatment such as screening, washing and oxidation, it still has a catalyst which can be directly used with the sufficient hydrogenation activity expected at the beginning. It is included in the new catalyst. The new catalyst may be a commercially available catalyst or a specially prepared catalyst. Further, the new catalyst may be subjected to a sulfurization treatment as a catalyst to be used before the hydrogenation treatment.

[Steps for extracting heavy oil desulfurization catalyst]

The step of extracting the heavy oil desulfurization catalyst of the present invention is to extract the heavy oil desulfurization catalyst from the top side of the reaction tower from the top side of the reaction tower (m is an integer of 2 or more) and the nth stage from the top side of the reaction tower. The step of a heavy oil desulfurization catalyst for satisfying an integer of n < m. The amount of vanadium accumulated in the catalyst in the reaction tower is greatly related to the filling position of the reaction tower, and the closer the catalyst position is to the reaction tower At the top of the tower, the amount of vanadium accumulated in the catalyst in the reaction tower becomes larger. Therefore, the cumulative amount of vanadium in the m-th heavy oil desulfurization catalyst from the top side of the reaction column is smaller than the cumulative amount of vanadium in the n-stage heavy oil desulfurization catalyst from the top side of the reaction column.

[Step of regenerating the extracted heavy oil desulfurization catalyst]

The step of regenerating the extracted heavy oil desulfurization catalyst is to regenerate the heavy oil desulfurization catalyst extracted from the mth stage from the top side of the reaction column. The regeneration treatment carried out in the step of regenerating the heavy oil desulfurization catalyst includes, for example, washing and removing oil by solvent, and removing carbon, sulfur, and nitrogen components by oxidation treatment, and removing the catalyst for blocking or fine granulation. A catalyst of normal shape or the like. The oxidation treatment is preferably carried out outside the reactor.

A preferred regeneration treatment of the used catalyst to which a large amount of carbon component is attached is first washed with a solvent using a solvent. Preferred solvents include, for example, toluene, acetone, alcohol, petroleum oils such as petroleum brain, kerosene, and gas oil. This washing treatment is, for example, a catalyst is passed between the hydrodesulfurization treatment reactors, the light oil is circulated to wash the catalyst, and then a gas such as nitrogen gas of about 50 to 300 ° C is passed to dry the catalyst. Alternatively, the light oil may be circulated and washed, and then directly extracted, and in order to prevent heat generation or natural ignition, the catalyst may be dried in advance in a state where the catalyst is wetted with light oil. Moreover, there is also a method for removing pulverization, pulverization catalyst, scale, etc. of the used catalyst by using the catalyst extracted from the reactor, and washing it with light oil and then washing with petroleum brain to make the catalyst easy to dry. . When the used catalyst is a small amount, the method of washing the catalyst with toluene is suitable for completely removing the oil from the catalyst.

In order to recover the catalytic activity of the catalyst by washing and removing oil and impurities, it is necessary to further remove the carbon component deposited on the catalyst by an oxidation treatment. The oxidation treatment is generally carried out by a combustion treatment which controls the atmosphere temperature and the oxygen concentration. When the ambient temperature is too high, or when the oxygen concentration is too high, the surface of the catalyst becomes high in temperature, and the crystal shape and the supported state of the supported metal are changed, and the pores of the support are reduced to lower the catalytic activity. Further, when the ambient temperature is too low or the oxygen concentration is too low, the removal of the carbon component by combustion may be insufficient, and the catalytic activity may not be sufficiently recovered. The atmosphere temperature for the combustion treatment is preferably 200 to 800 ° C, more preferably 300 to 600 ° C.

The concentration of oxygen in the combustion treatment preferably corresponds to the combustion method, and in particular, the contact state of the combustion gas with the catalyst is controlled. For example, the oxygen concentration in the combustion treatment is preferably from 1 to 21% by volume. It is important to adjust the temperature of the atmosphere, the oxygen concentration, the flow rate of the atmosphere gas, and the like in the combustion treatment, and to control the surface temperature of the catalyst, and to suppress the change in the crystal structure of the metal such as molybdenum and the state of the crystal particles in the catalyst during the combustion treatment. And to prevent the specific surface area of the catalyst and the decrease in the pore volume.

It is desirable to remove the pulverized catalyst or the like from the catalyst subjected to the combustion treatment, and only a catalyst having a normal shape is used as the regenerated catalyst. When the pulverized catalyst remains in the catalyst, the catalyst layer in the reactor is clogged and deflected, and the fluid pressure loss in the reactor is increased to continue the normal operation of the reactor.

[Steps of filling heavy oil desulfurization catalyst]

The step of filling the heavy oil desulfurization catalyst is a heavy oil desulfurization catalyst filled in the nth stage from the top side of the reaction tower, and the new catalyst is filled in the empty section of the reaction tower. As described above, the cumulative amount of vanadium in the heavy oil desulfurization catalyst of the mth stage from the top side of the reaction column is smaller than the cumulative amount of vanadium in the heavy oil desulfurization catalyst of the nth stage from the top side of the reaction column. Therefore, by filling the heavy oil desulfurization catalyst extracted and regenerated in the mth stage from the top side of the reaction column to the nth stage from the top side of the reaction column, the nth side from the top side of the reaction column can be made n The accumulation of vanadium in the heavy oil desulfurization catalyst of the section is reduced, and the ability to desulfurize the heavy oil of the entire reaction tower can be improved. Moreover, even if the accumulation of vanadium in the heavy oil desulfurization catalyst of the mth stage from the top side of the reaction tower is high, the desulfurization of the regenerated heavy oil can be obtained by extracting the mth section from the top side of the reaction tower. The catalyst is filled in the nth stage from the top side of the reaction column, and the amount of vanadium accumulated in the heavy oil desulfurization catalyst of the nth stage from the top side of the reaction column is reduced. Therefore, in the past, the used catalyst which cannot be reused due to the high accumulation amount of vanadium can be reused, and the used catalyst can be reused more effectively.

Since the heavy oil desulfurization catalyst of the mth stage from the top side of the reaction tower is extracted, the portion of the mth section from the top side of the reaction tower becomes empty. The empty section may be filled with a catalyst which is regenerated from the heavy oil desulfurization catalyst of the p-th stage (p>m) which is farther from the top of the reaction column than the mth stage, and may be filled with a new catalyst. Further, when the catalyst to be regenerated is filled, the catalyst which has been introduced into the reaction column may be completely extracted, and the same number of stages may be further divided into the same number from the bottom of the column.

[Metal tolerance MPr]

When the heavy oil desulfurization catalyst filled in the mth stage is regenerated and used in the nth stage, the metal tolerance amount MPr represented by the following formula (1) is preferably filled in the n+1th stage (only n+1<m) The catalyst is regenerated and the metal tolerance MPr is also large when used in the n+1 stage. Thereby, a section for regenerating the regenerated catalyst obtained by regenerating the heavy oil desulfurization catalyst filled in the mth stage can be appropriately selected, and the metal allowable amount MPr can be effectively increased.

. MPr = (PV / 2Vv) × {8 × 10 ⁵ × (PD) ^1.3 } × (Sp / Vp) - (VA1 + VA2). . . (1)

In the formula (1), each symbol is expressed as follows,

PV: pore volume (m ³ /kg) for new catalyst

Vv: When 1% by mass of vanadium is deposited on 1 kg of new catalyst, it is regarded as volume when vanadium sulfide is = 3.8 × 10 ^-6 (m ³ /% kg)

PD: average pore diameter (m) at the time of new catalyst

Sp: average external surface area (m ² ) of one particle in the case of a new catalyst

Vp: average volume of one particle (m ³ ) at the time of the new catalyst

VA1: Vanadium accumulation amount (% by mass) on the catalyst before re-feeding to the hydrogenation desulfurization unit (new catalyst standard)

VA2: Vanadium accumulation amount (% by mass) expected to be accumulated in the same apparatus for reductive desulfurization.

The metal tolerance amount MP of the above formula (1) is an index of the vanadium accumulation amount which can be tolerated in the predetermined period of the regenerated catalyst when the used catalyst is regenerated and reused as a regenerated catalyst. The larger the metal tolerance MPr, the more the amount of vanadium can be allowed to accumulate. When the metal tolerance MPr is less than 0, it means that the regenerated catalyst expires during the predetermined period of use of the regenerated catalyst. Before, the amount of vanadium accumulated has exceeded the allowable amount. Further, the value of the MPr of the commercially available catalyst is usually 50 or less when the vanadium deposition amount (VA1 + VA2) is 0% (new catalyst), the demetallization catalyst is 20 to 35, and the desulfurization catalyst is 10 to 25.

The first term of the above formula (1) indicates the allowable amount of vanadium accumulation in the case of a new catalyst, and is determined by the initial physical properties such as the pore volume of the new catalyst, and does not vary depending on the use of the catalyst and the regeneration treatment. PV is the pore volume of the new catalyst. Vv is a volume of vanadium when vanadium sulfide is deposited on 1 kg of a new catalyst, and is a constant of 3.8 × 10 ^-6 (m ³ /% kg). Further, in the usual hydrodesulfurization treatment, it is considered that vanadium is deposited as vanadium sulfide. The average pore diameter of the PD-based new catalyst. The constant 8 × 10 ⁵ × (PD) ^1.3 is the diffusion depth of vanadium in the pores of the catalyst obtained from the analysis results of various catalysts under review. The diffusion depth is usually proportional to (diffusion coefficient / reaction rate constant) ^-0.5 , and the diffusion coefficient is proportional to the pore diameter of the catalyst (refer to Chapter 27 of the Chemical Engineering Handbook of the revised fifth edition). However, according to studies by the present inventors, it has been found that the catalyst is proportional to (catalyst pore diameter PD) ^1.3 as described above.

When Sp is the new catalyst, the surface area outside the particle is actually the value of the average value. Further, when Vp is a new catalyst, the volume of one particle is the same as that of Sp. (Sp/Vp) is the average surface area per unit volume of each catalyst, and is specified by the shape at the time of manufacture of the new catalyst.

The VA1 of item 2 is the cumulative amount of vanadium accumulated in the use of a new catalyst in a hydrogenation desulfurization unit during a specific period (new catalyst reference mass) %) Actual or predicted value. VA2 is an actual value of the vanadium accumulation amount (new catalyst standard mass%) which is accumulated when the regeneration catalyst obtained by regenerating the new catalyst used in the hydrogenation desulfurization apparatus is used in the hydrodesulfurization apparatus. When VA1 is less than 0.5% by mass, vanadium accumulation in the catalyst is small, and the used catalyst can be reused even if it is not regenerated. Therefore, it is preferred that the catalyst used for the regeneration treatment has a VA1 of 1.0% by mass or more. Further, VA1 and VA2 are expressed by the amount of vanadium deposited on the catalyst, but vanadium contained in the catalyst may not necessarily be deposited on the catalyst. For example, the amount of vanadium which reacts with the catalyst component or the like in the pores of the catalyst or in the catalyst is also included in the above-mentioned accumulation amount of vanadium. The values of VA1 and VA2 of the used catalyst are usually in the range of 0 to 70% by mass. Further, the values of VA1 and VA2 in the upstream portion of the reaction zone of the A device are higher values of 30 to 70% by mass.

The sum of the metal tolerances MPr expressed by the above formula (1) in each stage of the reaction tower to be filled by the regenerated heavy oil desulfurization catalyst is preferably 0 or more, more preferably 1 or more and 5 or less. Further, the regenerated heavy oil desulfurization catalyst is filled in the reaction tower in a manner of preferably 3 or more and 5 or less. Thereby, the heavy oil desulfurization catalyst extracted from the m-th stage from the top side of the reaction column is filled in the n-th stage from the top side of the reaction column, thereby preventing the expiration of the predetermined period in which the regenerated catalyst is used, The accumulation of vanadium exceeds the allowable amount.

Example

Next, the present invention will be described in more detail by way of examples, but the present invention It is not intended to be limited by the embodiments.

[Characteristics of raw oil and heavy oil]

The following evaluations were carried out for the raw material heavy oils used in the respective examples and comparative examples. The heavy oil of the raw material uses atmospheric residual oil.

(density)

The density of the atmospheric residual oil at 15 ° C was measured in accordance with JIS K2249.

(dynamic viscosity)

The dynamic viscosity of the atmospheric residual oil at 50 ° C was measured in accordance with JIS K2283.

(content of residual carbon component)

The content of the residual carbon component of the atmospheric residual oil was measured in accordance with JIS K2270.

(content of asphaltene component)

The content of the asphaltene component of the atmospheric residue is determined according to IP 143.

(content of sulfur component)

The content of the sulfur component of the atmospheric residual oil was measured in accordance with JIS K2541.

(content of nitrogen component)

The content of the nitrogen component of the atmospheric residual oil was measured in accordance with JIS K2609.

(content of vanadium)

The vanadium content of the atmospheric residual oil was determined according to the Petroleum Institute Act JPI-5S-10-79.

(content of nickel)

The nickel content of the atmospheric residual oil was determined according to the Petroleum Institute Act JPI-5S-11-79.

(distillation trait)

The distillation property of the atmospheric residue was measured in accordance with JIS K2254.

[Characteristics of the catalyst]

The following evaluations were performed for the catalysts used in the respective examples and comparative examples.

For elemental analysis of vanadium and other elements, after firing at 650 ° C for 1 hour, the ash is dissolved with molybdenum and vanadium by acid, and then inductively coupled to the plasma luminescence absorption method, and the mixture of ash and lithium tetraborate is used for cobalt and nickel. The beads were prepared by high-frequency superheating and analyzed by fluorescent X-ray analysis. The carbon content is also desirably 15% (the carbon content in the catalyst is based on the acid-treated catalyst at 400 ° C or higher, and is not based on the amount of carbon in the target catalyst, and the following is the same as below). 10% or less. The carbon content is mostly about 10 to 70% in the used stage, but the carbon content can be reduced from the catalyst by the regeneration treatment. When the carbon content is too much, it will cover the surface of the catalyst to reduce the catalytic activity, but as long as the regeneration treatment is reduced The carbon content restores activity. Further, the analysis of carbon and sulfur was carried out by a C-S simultaneous analysis to analyze the pulverized sample. The average length of the catalyst was measured by arbitrarily extracting 10 particles from a vernier caliper and measuring the length perpendicular to the cross section and averaging. The average external surface area and average volume of one particle are calculated from the shape and average length of the cross-sectional area of the particle.

[Production of oil traits]

The produced oil obtained from the raw material heavy oil by hydrodesulfurization treatment in each of the examples and the comparative examples was evaluated in the same manner as the evaluation of the properties of the above-mentioned raw material heavy oil. Since the method for evaluating the properties of the oil to be produced is the same as the method for evaluating the properties of the above-mentioned raw material heavy oil, the description of the method for evaluating the properties of the oil is omitted.

[Manufacture of new catalyst used in each of Examples and Comparative Examples]

630 g of molybdenum oxide and 150 g of basic nickel carbonate in terms of NiO were dissolved in ion-exchanged water using 180 g of malic acid to prepare 2000 ml of an impregnation liquid. The water content of the impregnation liquid was adjusted in such a manner as to match the water absorption amount of the following support to obtain 4,000 g of a four-leaf type alumina support (specific surface area: 230 m ² /g, average pore diameter: 120 Å, pore volume: 0.69 ml/g). ) impregnated in the impregnation solution for 15 minutes. The alumina support impregnated with the impregnation liquid was dried at 120 ° C for 3 hours and calcined at 500 ° C for 5 hours to obtain a new catalyst 1.

[Manufacture of Regenerated Catalyst Used in Each of Examples and Comparative Examples] (Example 1)

- Hydrodesulfurization with a new catalyst -

The downflow fixed-bed reactor shown in Fig. 2 was divided into 4 beds (four equal parts by volume), and the city was filled in the most upstream bed (referred to as "the first bed", the same below). For the demetallization catalyst sold, the remaining 3 beds (2nd to 4th beds) were filled with the new catalyst 1. Further, the physical properties and metal allowable amounts of the new catalyst 1 are shown in Table 1 below. After the normal pre-vulcanization treatment, the atmospheric residual oil 1 having the properties shown in Table 2 below was used, and the sulfur component was adjusted to a constant value (0.3 mass% or less) under the reaction conditions shown in Table 3 below. Hydrodesulfurization treatment was carried out for 330 days at the reaction temperature. The reaction temperature on day 330 was 396 °C. The properties of the produced oil 1 obtained by hydrodesulfurization from normal pressure residual oil are shown in Table 4 below.

- Regeneration -

The catalyst 1 in the above reactor was washed with light oil, dried and cooled while flowing nitrogen gas, and the used catalyst was taken out from the second to fourth beds of the reactor. The used catalyst taken out from the third bed is hereinafter referred to as used catalyst 1, and the used catalyst taken out from the fourth bed is hereinafter referred to as used catalyst 2. The physical properties and metal allowable amounts of the used catalyst 1 and the used catalyst 2 are shown in Table 1 below. Subsequently, the cake and the powder are removed by sieving separation from the used catalyst 1. After removing the cake and the powder, a rotary firing furnace (rotation speed: 5 rpm) was used to supply 100% of nitrogen gas at a flow rate of 100 cc/min, and about 100 g of the used catalyst 1 was passed at 300 ° C. It was dried at the heating temperature for 1 hour. With Thereafter, a mixed gas of 50% nitrogen to 50% air was supplied at a flow rate of 100 cc/min, and calcined at a firing temperature of 450 ° C for 3 hours, and after the calcined used catalyst 1 was cooled, it was sieved. The catalyst 1 was separated from the used catalyst 1 to remove the cake and the powder, and the regenerated catalyst 1 was obtained. Regenerated catalyst 2 was obtained from the used catalyst 2 in the same manner. The physical properties and metal allowable amounts of the regenerated catalyst 1 and the regenerated catalyst 2 are shown in Table 1 below.

- Hydrodesulfurization treatment using regenerated catalyst -

The downflow fixed bed reactor is divided into 4 beds (four equal parts by volume), and the first bed is filled with a commercially available demetallization catalyst, and the second bed is filled with regenerated catalyst 2, the third and The fourth bed was filled with a new catalyst 1. After the normal pre-vulcanization treatment, the atmospheric residual oil having the properties shown in the following Table 2 was used, and the sulfur component was made constant (0.3 mass% or less) under the reaction conditions shown in Table 3 below. Hydrodesulfurization treatment was carried out for 330 days while adjusting the reaction temperature. The reaction temperature on day 330 was 400 °C. The properties of the resulting oil 2A obtained by hydrodesulfurization from normal pressure residual oil are shown in Table 4 below.

- Regeneration -

The regenerated catalyst 2 is regenerated by the same method as the regeneration treatment of the catalyst 1 used as described above to obtain the regenerated catalyst 3A. The physical properties and metal tolerance of the regenerated catalyst 3A are shown in Table 1 below.

(Comparative Example 1)

- Hydrodesulfurization treatment with new catalyst -

As in Example 1, the atmospheric pressure residual oil having the properties shown in Table 2 below and the new catalyst 1 were used, and hydrodesulfurization treatment was carried out under the reaction conditions shown in Table 3 below.

- Regeneration -

As in Example 1, the used catalyst 1 and the used catalyst 2 were regenerated to obtain the regenerated catalyst 1 and the regenerated catalyst 2.

- Hydrodesulfurization treatment using regenerated catalyst -

Dividing the downflow fixed bed reactor into 4 beds (4 aliquots on a volume basis), filling the first bed with a commercially available demetallization catalyst, and filling the second and third beds below with a new catalyst 1 The fourth heavy charge is filled with the regenerated catalyst 2. After the normal pre-vulcanization treatment, the atmospheric residual oil having the properties shown in the following Table 2 was used, and the sulfur component was made constant (0.3 mass% or less) under the reaction conditions shown in Table 3 below. Hydrodesulfurization treatment was carried out for 330 days while adjusting the reaction temperature. The reaction temperature on day 330 was 413 °C. The properties of the produced oil 2B obtained by hydrodesulfurization from normal pressure residual oil are shown in Table 4 below.

- Regeneration -

The regenerated catalyst 2 is regenerated by the same method as the regeneration treatment of the catalyst 1 used as described above to obtain the regenerated catalyst 3B. The physical properties and metal tolerance of the regenerated catalyst 3B are shown in Table 1 below.

From the results of Example 1 and Comparative Example 1, it was found that the catalyst used in the fourth bed was regenerated and compared with the case where the catalyst used in the fourth bed was regenerated and directly filled in the fourth bed. By filling in the second bed, the sulfur component and the asphaltene content of the oil produced by the hydrodesulfurization treatment can be further reduced.

Claims (4)

A method for recycling a heavy oil desulfurization catalyst, which is used in a device for inputting heavy oil of raw materials from the top side of a reaction column packed with a catalyst, and for hydrogenating desulfurization raw materials from the bottom side of the reaction tower A method for regenerating a catalyst for a hydrogenation desulfurization apparatus for discharging heavy oil, comprising the steps of: dividing a heavy oil desulfurization catalyst filled in the reaction column into a plurality of stages of 2 or more, and then extracting a tower from the reaction tower a step of the heavy oil desulfurization catalyst of the m-th stage of the top side (m is an integer of 2 or more) and a heavy oil desulfurization catalyst from the n-stage of the top side of the reaction column (n satisfies an integer of n < m), and a step of regenerating the heavy oil desulfurization catalyst extracted from the m-stage of the top side of the reaction column, and filling the above-mentioned heavy oil desulfurization catalyst regenerated in the nth stage from the top side of the reaction column, and by the aforementioned mth The step of filling the regenerated catalyst or new catalyst from the section of the aforementioned mth section away from the top of the aforementioned reaction column. A method for recycling a heavy oil desulfurization catalyst according to the first aspect of the invention, wherein the metal is allowed to be represented by the following formula (1) when the heavy oil desulfurization catalyst of the mth stage is regenerated and used for the nth stage The amount of MPr is larger than the metal tolerance MPr when the catalyst is regeneratively filled in the n+1th stage (only n+1<m) and used in the same n+1th stage. MPr = (PV / 2Vv) × {8 × 10 ⁵ × (PD) ^1.3 } × (Sp / Vp) - (VA1 + VA2). . . (1) In the formula (1), each symbol indicates the pore volume (m ³ /kg) Vv at the time of PV: new catalyst, respectively: when the vanadium of 1 mass% is deposited on 1 kg of the new catalyst Volume for vulcanization of vanadium = 3.8 × 10 ^-6 (m ³ /% kg) PD: average pore diameter (m) of the new catalyst Sp: average external surface area (m ² ) of one particle at the time of the new catalyst Vp: Average volume of one particle at the time of the new catalyst (m ³ ) VA1: Vanadium accumulation amount (% by mass) on the catalyst before the hydrogenation desulfurization device (new catalyst standard) VA2: Additional hydrogenation desulfurization in the same apparatus It is expected to accumulate vanadium accumulation (% by mass). A method for recycling a heavy oil desulfurization catalyst according to claim 1 or 2, wherein the total amount of the metal capacity MPr represented by the above formula (1) of each of the stages of the reaction tower filled with the regenerated heavy oil desulfurization catalyst is The above-described regenerated heavy oil desulfurization catalyst is charged to the above reaction column in a manner of being synthesized to 0 or more. A method for recycling a heavy oil desulfurization catalyst according to the third aspect of the invention, wherein the total amount of the metal capacity MPr is 1 or more and 5 or less, and the regenerated heavy oil desulfurization catalyst is filled in the reaction column.