KR102297022B1 - Method for regenerating and utilizing heavy-oil desulfurization catalyst - Google Patents

Abstract

The method for regenerating the heavy oil desulfurization catalyst of the present invention comprises a step of extracting a heavy oil desulfurization catalyst charged in one heavy oil desulfurization apparatus and having an allowable metal amount MPr1 of less than 0 represented by the following formula (1); It is characterized by having a step of regenerating the desulfurization catalyst, and a step of charging the regenerated heavy oil desulfurization catalyst into at least one different different heavy oil desulfurization apparatus.
MPr1 = (PV/2Vv)×{8×10 ⁵ ×(PD) ^1.3 }×(Sp/Vp)-(VA1+VA2)
Here, PV is the pore volume at the time of the new catalyst, Vv is the volume when 1 mass % of vanadium is deposited on 1 kg of the new catalyst when it is regarded as vanadium sulfide, and PD is the average pore diameter at the time of the new catalyst where Sp is the average external surface area of one grain in the new catalyst, Vp is the average volume of one grain in the new catalyst, VA1 is the vanadium deposition amount (mass %) accumulated in the original device, and VA2 is the same device It is the amount of vanadium deposition in the case of using the catalyst regenerated in

Description

Method for regenerating heavy oil desulfurization catalyst

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

In petroleum refining, there are many processes for refining various fractions by hydrorefining treatment, and various catalysts for it have been developed. Examples of such catalysts include desulfurization and denitrification catalysts such as naphtha, kerosene and light oil, desulfurization and denitrification catalysts of heavy gas oil, decomposition catalysts, and desulfurization and denitrification catalysts such as resid and heavy oil. Among them, the catalyst used for hydrorefining treatment of naphtha, kerosene, light oil, etc. having a relatively low boiling point and little content of metallic impurities such as vanadium, has little degree of deterioration due to use.

Catalysts used for hydrorefining naphtha, kerosene, gas oil, etc. do not deteriorate due to metallic impurities such as vanadium, and the deterioration of the catalyst is due to accumulation of a small amount of carbonaceous material. Therefore, if carbon was removed from the catalyst by combustion, the catalyst could be reused. Moreover, also with respect to carbonaceous removal, since the amount of carbonaceous material on the catalyst was small, the catalyst could be regenerated without requiring strict combustion control. In addition, some of the catalysts used have a low degree of deterioration, and such catalysts can be reused as they are without being subjected to regeneration treatment.

In recent years, hydrorefining process catalysts, such as heavy gas oil and vacuum gas oil, are also regenerated and reused, and the regeneration method and reuse method of the catalyst have been established. For example, the hydrocracking catalyst used in the heavy gas oil hydrocracking process and the hydrodenitrification catalyst used for its pretreatment are regenerated by hydrogen activation or oxygen activation, and are reused. Since the catalyst used for the hydrorefining treatment of these effluent oils is used for the raw material oil with few metallic impurities, there is little deposition on the catalyst phase of metals, such as vanadium. Also, the amount of carbonaceous deposited on the catalyst is small, and the carbonaceous deposited on the catalyst is liable to burn. For this reason, since the catalyst surface does not become that high at the time of regeneration by combustion, the change in the pore structure of the catalyst and the supported state of the active metal by the regeneration treatment is small, so that it can be used again for the treatment of effluent oil such as heavy gas oil and vacuum gas oil. was possible (see Non-Patent Document 1).

However, heavy oil containing a fraction having a higher boiling point or a fraction that cannot be distilled contains a large amount of components prone to carbonitization such as asphaltene and metal impurities, and contains a large amount of a large amount on the spent catalyst after being used for hydrorefining treatment. Carbonaceous and metallic powders are deposited. Since the carbonaceous material cannot be simply removed from the spent catalyst in which the carbonaceous material and the metal component are accumulated at the same time, the carbonaceous material must be removed at a high combustion temperature. For this reason, the change in the pore structure of the catalyst and the supported state of the active metal by the regeneration treatment increased, and the function of the catalyst after removing the carbonaceous material was remarkably reduced (see Non-Patent Document 2 and Non-Patent Document 3). In this regard, the catalyst used for the hydrorefining treatment of heavy oil was disposed of without being reused.

However, it is very important to regenerate and reuse the catalyst used in the hydrorefining treatment of heavy oil for waste reduction and catalyst cost reduction. As a recycling method of a regeneration catalyst, the regeneration method of the heavy oil hydroprocessing catalyst described in patent document 1, and the hydrodesulfurization method of heavy oil described in patent document 2 are known, for example. According to the regeneration method of the heavy oil hydroprocessing catalyst described in Patent Document 1, the catalyst deactivated by use in the heavy oil hydrorefining treatment process is regenerated and calculated from the pore volume, pore diameter, vanadium deposition amount and external surface area per volume. The regenerative hydroprocessing catalyst in which the allowable metal amount to be used is a specific value can be used again for the hydroprocessing of heavy oil. Moreover, according to the hydrodesulfurization method of heavy oil described in Patent Document 2, a catalyst that has been deactivated due to use in a hydroprocessing process for heavy oil or the like and has not been used can be regenerated and effectively utilized.

Japanese Patent No. 3708381 Japanese Patent No. 3527635

Studies in Surface and Catalysis, vol. 88, P199 (1994) Catal. Today, vol. 17, No. 4, P539 (1993) Catal. Rev. Sci. Eng., 33 (3&4), P281 (1991)

However, in the method for regenerating the heavy oil hydroprocessing catalyst described in Patent Document 1, the physical properties of the spent catalyst serving as the raw material of the regenerated catalyst depend on the raw material and operating conditions, and greatly affect the regeneration. In a device with a high , it was not necessarily usable as a regeneration catalyst. In addition, the hydrodesulfurization method of heavy oil described in Patent Document 2 only proposes a regeneration method limited to one time per device, and is not a continuous and stable regeneration method. Then, an object of this invention is to provide the regeneration utilization method of the heavy oil desulfurization catalyst which can reuse the used catalyst more effectively.

As a result of intensive research, the present inventors have found that even if it is a catalyst that has not been used for regeneration in the past, which has been deactivated by using it in heavy oil hydrorefining treatment, the pore volume, the pore diameter, the vanadium deposition amount, and the allowable metal amount calculated from the external surface area per volume, The present invention has been completed by finding that it is possible to utilize the regenerated catalyst as stably as possible in many apparatuses by determining whether the regenerated catalyst can be used in other apparatuses or not. That is, the present invention is as follows.

[1] A step of extracting a heavy oil desulfurization catalyst charged in one heavy oil desulfurization device and having a metal allowable amount MPr1 of less than 0 represented by the following formula (1), a step of regenerating the extracted heavy oil desulfurization catalyst, and regeneration A method for regenerating and using a heavy oil desulfurization catalyst comprising the step of charging the used heavy oil desulfurization catalyst into at least one different different heavy oil desulfurization apparatus.

MPr1 = (PV/2Vv)×{8×10 ⁵ ×(PD) ^1.3 }×(Sp/Vp)-(VA1+VA2)...(1)

In Formula (1), each symbol represents the following, respectively.

PV: Pore volume at the time of new catalyst (m ³ /kg)

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

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

Sp: Average external surface area of one grain at the time of new catalyst (m ² )

Vp: Average volume of 1 grain at the time of new catalyst (m ³ )

VA1: Vanadium deposition amount (mass %) accumulated in the original device (based on the new catalyst)

VA2: Vanadium deposition amount (mass %) when catalyst regenerated in the same apparatus is used (based on new catalyst)

[2] In the step of charging the regenerated heavy oil desulfurization catalyst into at least one different heavy oil desulfurization device, the regenerated heavy oil desulfurization catalyst is different so that the metal allowable amount MPr2 expressed by the following formula (2) is 0 or more The method for regenerating and using the heavy oil desulfurization catalyst according to the above [1], which is charged in a heavy oil desulfurization apparatus.

MPr2 = (PV/2Vv)×{8×10 ⁵ ×(PD) ^1.3 }×(Sp/Vp)-(VA1+VB1)... (2)

In Formula (2), each symbol represents the following, respectively.

PV: Pore volume at the time of new catalyst (m ³ /kg)

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

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

Sp: Average external surface area of one grain at the time of new catalyst (m ² )

Vp: Average volume of 1 grain at the time of new catalyst (m ³ )

VA1: Vanadium deposition amount (mass %) accumulated in the original device (based on the new catalyst)

VB1: Vanadium deposition amount (mass %) accumulated when a catalyst regenerated in a new device is used (based on the new catalyst)

[3] The method for regenerating the heavy oil desulfurization catalyst according to the above [2], wherein different heavy oil desulfurization apparatuses are charged so that the metal permissible amount MPr2 represented by the formula (2) is 1 or more and 5 or less.

ADVANTAGE OF THE INVENTION According to this invention, the regeneration utilization method of a heavy oil desulfurization catalyst which can reuse a spent catalyst more effectively can be provided.

1 is a schematic diagram for explaining a downflow type fixed bed reactor used in an embodiment of the present invention.

The regeneration utilization method of a heavy oil desulfurization catalyst in this invention has the process of extracting a heavy oil desulfurization catalyst, the process of regenerating a heavy oil desulfurization catalyst, and the process of filling a heavy oil desulfurization apparatus. Hereinafter, a method for regenerating the heavy oil desulfurization catalyst of the present invention will be described in detail.

[Process of extracting heavy oil desulfurization catalyst]

The step of extracting the heavy oil desulfurization catalyst in the present invention is a step of extracting a heavy oil desulfurization catalyst that is charged in one heavy oil desulfurization device and has a metal allowable amount MPr1 represented by the following formula (1) is less than 0.

MPr1 = (PV/2Vv)×{8×10 ⁵ ×(PD) ^1.3 }×(Sp/Vp)-(VA1+VA2)...(1)

In Formula (1), each symbol represents the following, respectively.

PV: Pore volume at the time of new catalyst (m ³ /kg)

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

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

Sp: Average external surface area of one grain at the time of new catalyst (m ² )

Vp: Average volume of 1 grain at the time of new catalyst (m ³ )

VA1: Vanadium deposition amount (mass %) accumulated in the original device (based on the new catalyst)

VA2: Vanadium deposition amount (mass %) when catalyst regenerated in the same apparatus is used (based on new catalyst)

(Heavy Oil Desulfurization Unit)

The heavy oil desulfurization apparatus in the present invention performs desulfurization, denitrification, deoxygenation, and hydrogenation and decomposition of hydrocarbons for heavy oil by hydrorefining treatment. Moreover, the heavy oil desulfurization apparatus can perform not only hydrorefining, such as desulfurization and denitrification, but also demetallation and hydrocracking of asphaltenes. In view of this, the heavy oil desulfurization apparatus is not only used for the purpose of desulfurization of heavy oil, but is also used in combination with resid upgrading processes such as resid fluid catalytic cracking (RFCC), coker, and solvent degassing. The product heavy oil obtained by the heavy oil desulfurization apparatus is used, for example, as an RFCC raw material, a coker raw material, and a low sulfur product heavy oil.

Next, the hydrorefining process performed by the heavy oil desulfurization apparatus is demonstrated. The hydrorefining treatment performed in the heavy oil desulfurization apparatus is not particularly limited as long as it can desulfurize the heavy oil, and the hydrorefining treatment performed in the heavy oil desulfurization apparatus will be described by taking the hydrorefining treatment by a fixed bed reactor as an example. Heavy oil used as a raw material for hydrorefining treatment contains residues such as atmospheric resid and vacuum resid. However, heavy oil does not include those which consist only of effluent oil, such as kerosene, light oil, and vacuum gas oil. For example, heavy oil contains 1 mass % or more of sulfur content, 200 mass ppm or more of nitrogen content, 5 mass % or more of xanthan content, 5 mass % or more of vanadium content, and 0.5 mass % or more of asphaltene content. Examples of the heavy oil include crude oil other than atmospheric residual oil, asphalt oil, pyrolysis oil, tar sand oil, and mixed oils thereof. The heavy oil used as the raw material for the hydrorefining treatment is not particularly limited as long as it is as described above, but atmospheric resid, vacuum resid, vacuum resid, or mixed oil of asphalt oil and cracked light oil, etc. are suitably used as the raw material for hydrorefining treatment.

The reaction temperature of the hydrorefining treatment is preferably 300 to 450°C, more preferably 350 to 420°C, still more preferably 370 to 410°C. The hydrogen partial pressure in the hydrorefining treatment is preferably 7.0 to 25.0 MPa, more preferably 10.0 to 18.0 MPa. The liquid space velocity of the hydrogenation process is purified, preferably 0.01~10h ^-1, and more preferably in the 0.1~5h ^-1, more preferably 0.1~1h ^-1. Hydrogen / feed oil ratio of the hydrogenation process is purified, preferably 500~2,500Nm ³ / kl, and more preferably 700~2,000Nm ³ / kl. In addition, adjustment of the sulfur content and metal content (vanadium, nickel, etc.) content of the product oil obtained by the hydrorefining process can be performed by adjusting suitably the reaction temperature in a hydrorefining process, for example.

(Heavy Oil Desulfurization Catalyst)

The heavy oil desulfurization catalyst in the present invention is a catalyst in which a catalyst normally used for desulfurization of heavy oil (including a catalyst that has been subjected to sulfurization treatment) is used for hydrorefining treatment of heavy oil at least once. Usually, carbon, vanadium, etc. adhere to the catalyst by use. The heavy oil desulfurization catalyst is not particularly limited as long as it is used for hydrorefining treatment of heavy oil. For example, an alumina catalyst in which molybdenum is supported on an alumina carrier is used as a heavy oil desulfurization catalyst. In this case, cobalt or nickel is used as a promoter.

The alumina carrier may contain at least one of phosphorus, silicon, and boron. The content in the heavy oil desulfurization catalyst of at least one of phosphorus, silicon and boron in terms of oxide is preferably 30.0 mass % or less, more preferably 0.1 to 10.0 mass %, still more preferably 0.2 -5.0 mass %. However, the content of at least one of phosphorus, silicon, and boron in the catalyst is oxidized at a temperature of 400° C. or higher, so that weight loss due to heating does not occur, as a reference mass, and at least one of phosphorus, silicon and boron Let content be expressed in mass %.

Content of molybdenum in a heavy oil desulfurization catalyst becomes like this. Preferably it is 0.1-25.0 mass %, More preferably, it is 0.2-8.0 mass %. Moreover, content of cobalt or nickel in a heavy oil desulfurization catalyst becomes like this. Preferably it is 0.1-10.0 mass %, More preferably, it is 0.2-8.0 mass %. On the other hand, the metal content in the heavy oil desulfurization catalyst is defined as the reference mass of the oxidation treatment at a temperature of 400° C. or higher so that weight loss due to heating does not occur, and the mass of the oxide of the metal to be measured is expressed in mass%.

Since heavy oil contains many asphaltenes and vanadium, carbon powder and vanadium are deposited in the heavy oil desulfurization catalyst used for hydrorefining processing of heavy oil. The carbon powder coats the catalyst surface of the heavy oil desulfurization catalyst and reduces the catalytic activity of the heavy oil desulfurization catalyst. However, the carbon powder deposited on the heavy oil desulfurization catalyst can be removed by regeneration treatment such as solvent extraction and oxidative combustion treatment, and the catalytic activity of the heavy oil desulfurization catalyst can be increased. The carbon content in the used heavy oil desulfurization catalyst before the regeneration treatment is preferably 10 to 70 mass%, more preferably 0.2 to 8.0 mass%. If the carbon content in the heavy oil desulfurization catalyst is greater than 70% by mass, the catalyst activity is not sufficiently increased even after regeneration treatment, or because regeneration treatment at a high temperature is necessary to increase the catalyst activity, the strength of the catalyst is reduced. There are cases. On the other hand, the carbon content in the heavy oil desulfurization catalyst is defined as the reference mass of the carbon content in the target catalyst, which has been subjected to oxidation treatment at a temperature of 400° C. or higher so that weight loss due to heating does not occur, and the mass of the carbon content in the target catalyst is expressed in mass%.

The content of vanadium in the used heavy oil desulfurization catalyst before the regeneration treatment is preferably 35 mass% or less, and more preferably 20 mass% or less. If the content of vanadium is greater than 35% by mass, the catalyst activity may not be sufficiently increased even if the regeneration treatment is performed, or the strength of the catalyst may be reduced due to the need for regeneration treatment at a high temperature to increase the catalyst activity. . Vanadium deposited on the heavy oil desulfurization catalyst cannot be usually removed by regeneration treatment.

The content of vanadium in the spent catalyst hardly changes between before and after the regeneration treatment. For this reason, based on the metal allowable amount MPr1 calculated using the content of vanadium in the spent catalyst, it is possible to discriminate between a catalyst that can be regenerated before the regeneration treatment and a catalyst that cannot be used even if it is regenerated. Since it is wasteful to regenerate the catalyst that cannot be used even after being regenerated, it is preferable to select and remove the catalyst that cannot be used even if regenerated from the used catalyst before the regeneration treatment.

Catalysts used for hydrorefining treatment and catalysts subjected to oxidation treatment, particularly combustion treatment for regeneration treatment, change the pore structure of the catalyst and the supported state of the active metal due to heating of the catalyst at the time of treatment, so that the catalytic activity decreases there is As an index for evaluating these, there are specific surface area and pore capacity of the catalyst. The specific surface area and pore capacity of the catalyst are gradually reduced by hydrorefining treatment and adhesion of impurities, and are likely to decrease even by regeneration treatment. It is preferable that the specific surface area and the pore volume of the used heavy oil desulfurization catalyst be 70% or more, respectively, of the specific surface area and the pore volume of the new catalyst. The specific surface area of the used heavy oil desulfurization catalyst is preferably 60 to 220 m ² /g, more preferably 100 to ²⁰⁰ m 2 /g. Moreover, the pore volume of the used heavy oil desulfurization catalyst becomes like this. Preferably it is 0.3-1.2 cc/g, More preferably, it is 0.4-0.8 cc/g.

On the other hand, a new catalyst is a catalyst manufactured as a catalyst and has never been used for a hydrorefining process. In addition, the new catalyst includes a catalyst that was once used for the hydrorefining treatment, but was discontinued for a short period of time due to equipment troubles and the like and used again as it is. That is, even if it is temporarily used, even without special activation treatment or regeneration treatment such as selection, washing and oxidation after being taken out from the reactor, a catalyst that can be used as it is because it still has sufficient hydrogenation activity from the beginning is also included in the new catalyst. Included. A commercially available catalyst may be sufficient as a new catalyst, and the catalyst specially prepared may be sufficient as it. Further, the new catalyst may be a catalyst subjected to a sulfurization treatment as a pretreatment for use in the hydrogenation treatment.

(Metal Allowance)

The allowable metal amount MPr1 in the formula (1) is an index for judging whether or not the catalyst regenerated by the catalyst used in the heavy oil desulfurization apparatus can be used for a predetermined period in the same heavy oil desulfurization apparatus. As the metal allowable amount MPr1 is larger than 0, since a large amount of vanadium can be allowed to be deposited, the catalyst can be used for a predetermined period in the same heavy oil desulfurization apparatus with a margin. On the other hand, when MPr1 is less than 0 (ie, a negative value), the activity of the catalyst regenerated by deposition of vanadium before the service period of the catalyst reaches a predetermined period is insufficient for use in the heavy oil desulfurization device. becomes Therefore, by using the metal allowance MPr1, it is possible to select a heavy oil desulfurization catalyst that does not have an activity tolerant to use in the heavy oil desulfurization device from the heavy oil desulfurization catalyst deactivated by vanadium deposition on the catalyst, A heavy oil desulfurization catalyst that cannot be used in a heavy oil desulfurization apparatus can be specified. And in the present invention, a catalyst having an allowable metal amount MPr1 of less than 0 is judged as a catalyst extracted from the heavy oil desulfurization apparatus. Hereinafter, the above formula (1) will be described in detail.

The metal allowable amount MPr1 in the formula (1) is an index of the vanadium deposition amount that can be further tolerated until the catalyst is deactivated by vanadium deposition and its life is reached. The smaller this value, the more unacceptable vanadium deposition. In the present invention, MPr1 of the catalyst discharged from the heavy oil desulfurization unit is less than zero. On the other hand, the value of MPr1 of the commercially available catalyst is usually 50 or less even when the vanadium deposition amount (VA1 + VA2) is 0% (new catalyst), and is 20 to 35 in the demetallic catalyst and 10 to 25 in the desulfurization catalyst.

The first term of the above formula (1) represents the allowable amount of vanadium deposition in the new catalyst, and is determined by the initial physical properties such as the pore volume of the new catalyst, and is not changed by the use of the catalyst and the regeneration treatment. PV is the pore volume at the time of a new catalyst. Vv is the volume of vanadium when 1 mass % of vanadium is deposited on 1 kg of new catalyst, when the vanadium is regarded as vanadium sulfide, and is a constant 3.8×10 ^-6 (m ³ /% kg). On the other hand, it is thought that vanadium is deposited as vanadium sulfide in a normal hydrorefining process. PD is the average pore diameter at the time of the new catalyst. The constant 8×10 ⁵ ×(PD) ^1.3 is the diffusion depth of vanadium into the pores of the catalyst obtained from the analysis results of various catalysts studied. The diffusion depth is usually proportional to (diffusion coefficient/reaction rate constant) ^-0.5 , and it is considered that the diffusion coefficient is proportional to the catalyst pore diameter (refer to Chapter 27 of the Handbook of Chemical Engineering, 5th Edition). However, according to the study of the present inventors, it was found that in the ^{present catalyst, it is proportional to (catalyst pore diameter PD) 1.3 as above.}

Sp is the outer surface area of one grain at the time of a new catalyst, and is a value as an average value in reality. In addition, Vp is the volume of one grain at the time of a new catalyst, and is an average value similarly to Sp. (Sp/Vp) is the outer surface area per volume of each catalyst as an average, and is specified by the shape at the time of preparation of the new catalyst.

In VA1 of claim 2, the new catalyst is used for a predetermined period in a heavy oil desulfurization device (to be able to distinguish it from at least one different heavy oil desulfurization device described later, this heavy oil desulfurization device is hereinafter referred to as “device A”). It is an actual value or a predicted value of the vanadium deposition amount (based on the new catalyst (mass %)) accumulated at the time. VA2 is an actual or predicted value of the amount of vanadium deposition (based on the new catalyst (mass %)) accumulated when the regeneration catalyst regenerated by the new catalyst used in the A device is used in the A device for a necessary period. When VA1 is less than 0.5 mass %, there is little deposition of vanadium in a catalyst, and even if it does not regenerate, a used catalyst can be reused. Therefore, it is preferable that the used catalyst to be regenerated has VA1 of 1.0 mass% or more. On the other hand, although VA1 and VA2 are expressed as the deposition amounts of vanadium deposited on the catalyst, vanadium contained in the catalyst does not necessarily have to be deposited on the catalyst. For example, the amount of vanadium entering the pores of the catalyst or entering the catalyst or reacting with a catalyst component or the like is also included in the deposition amount of vanadium. The values of VA1 and VA2 of the used catalyst are usually 0 to 70% by mass in many cases. Further, in the upstream part of the reaction zone of the device A, the values of VA1 and VA2 are as high as 30 to 70 mass %.

[Process of regenerating heavy oil desulfurization catalyst]

In the step of regenerating the heavy oil desulfurization catalyst in the present invention, the extracted heavy oil desulfurization catalyst is regenerated. The regeneration treatment performed in the step of regenerating the heavy oil desulfurization catalyst includes, for example, removal of oil content by solvent washing, removal of carbon content, sulfur content, nitrogen content, etc. by oxidation treatment, and agglomerated or fine-grained catalyst. selection of a catalyst of a normal shape by removal and the like. The oxidation treatment is preferably performed outside the reactor.

In a preferred regeneration treatment of the spent catalyst to which a large amount of carbon powder adheres, the spent catalyst is first washed with a solvent. Preferred solvents include, for example, toluene, acetone, alcohol, and petroleum products such as naphtha, kerosene and light oil. In this washing process, for example, while the catalyst is in the hydrorefining reactor, light oil is circulated to wash the catalyst, and then, a gas such as nitrogen gas at about 50 to 300°C is circulated to dry the catalyst. Alternatively, the light oil may be circulated and washed and then taken out as it is, to prevent heat generation or spontaneous ignition, the catalyst may be wetted with light oil and dried when necessary. In addition, there is also a method of removing the pulverization, differentiation catalyst, scale, etc. of a lump from the spent catalyst extracted from the reactor, washing it with light oil, and further washing with naphtha to make the catalyst easier to dry. When the spent catalyst is small, a method of washing the catalyst with toluene is suitable for completely removing the oil content from the catalyst.

In order to recover the catalytic activity of the catalyst from which oil and impurities have been removed by washing, it is necessary to further remove the carbon powder deposited on the catalyst by oxidation treatment. The oxidation treatment is generally performed by a combustion treatment in which the atmospheric temperature and the oxygen concentration are controlled. When the atmospheric temperature is too high or the oxygen concentration is too high, the catalyst surface becomes high temperature, the crystal form and the supported state of the supported metal change, or the pores of the support decrease, thereby reducing the catalytic activity. In addition, when the atmospheric temperature is too low or the oxygen concentration is too low, the removal of carbon by combustion becomes insufficient, and catalyst activity may not fully recover. The atmospheric temperature of the combustion treatment is preferably 200 to 800°C, more preferably 300 to 600°C.

It is preferable to control the oxygen concentration in a combustion process corresponding to the combustion method, especially the contact state of combustion gas and a catalyst. For example, the oxygen concentration in a combustion process becomes like this. Preferably it is 1-21 volume%. In the combustion treatment, the surface temperature of the catalyst is controlled by adjusting the atmospheric temperature, oxygen concentration, and the flow rate of the atmospheric gas, etc., and the crystal structure of a metal such as molybdenum in the catalyst during the combustion treatment and the state in which the crystal grains are supported change It is important to suppress or prevent a decrease in the specific surface area and pore capacity of the catalyst.

It is preferable to remove the differentiated catalyst or the like from the combustion-treated catalyst, and to use only the catalyst having a normal shape as the regeneration catalyst. If the differentiated catalyst remains in the catalyst, clogging and drifting occurs in the catalyst layer in the reactor, or the pressure loss of the fluid in the reactor becomes large, and the normal operation of the reactor may not be continued.

[Process of filling the heavy oil desulfurization device]

In the step of charging the heavy oil desulfurization apparatus in the present invention, the regenerated heavy oil desulfurization catalyst is charged into at least one other different heavy oil desulfurization apparatus. As a result, even a used catalyst that cannot be reused in the heavy oil desulfurization apparatus from which the heavy oil desulfurization catalyst is extracted in the step of extracting the heavy oil desulfurization catalyst can be reused, and the used catalyst can be reused more effectively.

The heavy oil desulfurization apparatus for charging the regenerated heavy oil desulfurization catalyst is not particularly limited as long as it is a different heavy oil desulfurization apparatus from the heavy oil desulfurization apparatus that extracted the heavy oil desulfurization catalyst in the step of extracting the heavy oil desulfurization catalyst. In addition, the number of heavy oil desulfurization apparatuses which fill the regenerated heavy oil desulfurization catalyst may be one, and two or more units may be sufficient as them. Since the heavy oil desulfurization apparatus in the step of filling the heavy oil desulfurization apparatus is the same heavy oil desulfurization apparatus as that described in the step of extracting the heavy oil desulfurization catalyst, the description of the heavy oil desulfurization apparatus is omitted.

In this invention, you may make it fill the regenerated heavy oil desulfurization catalyst in the heavy oil desulfurization apparatus in which the metal allowable amount MPr2 represented by following formula (2) becomes 0 or more. Thereby, it is preferable that another heavy oil desulfurization apparatus capable of reusing the used catalyst can be appropriately selected.

MPr2 = (PV/2Vv)×{8×10 ⁵ ×(PD) ^1.3 }×(Sp/Vp)-(VA1+VB1)... (2)

In Formula (2), each symbol represents the following, respectively.

PV: Pore volume at the time of new catalyst (m ³ /kg)

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

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

Sp: Average external surface area of one grain at the time of new catalyst (m ² )

Vp: Average volume of 1 grain at the time of new catalyst (m ³ )

VA1: Vanadium deposition amount (mass %) accumulated in the original device (based on the new catalyst)

VB1: Vanadium deposition amount (mass %) accumulated when a catalyst regenerated in a new device is used (based on the new catalyst)

The allowable metal amount MPr2 in the formula (2) is a catalyst obtained by regenerating the catalyst used in the heavy oil desulfurization unit (unit A) for a predetermined period in a heavy oil desulfurization unit (hereinafter, unit B) different from the heavy oil desulfurization unit (unit A). It is an indicator for judging whether it is usable or not. As the metal allowable amount MPr2 is larger than 0, the catalyst can be used in the B device for a predetermined period with a margin. On the other hand, when MPr2 is less than 0, the activity of the regenerated catalyst becomes insufficient for use in the device B due to deposition of vanadium before the service period of the catalyst reaches a predetermined period. However, in the case of VA2>VB1, even if it cannot be used in the A device, there is a possibility that it can be used in the B device. It becomes possible to quantitatively judge this by using the parameter|index of metal allowable amount MPr2. Although the metal allowable amount MPr2 in device B is 0 or more, Preferably it is 1 or more and 5 or less, More preferably, it is 3 or more and 5 or less. In addition, since the said Formula (2) is the same as the said (1) except having changed "VA1+VA2" into "VA1+VB1", the description of the said Formula (2) is abbreviate|omitted. In addition, VB1 is an actual value or predicted value of the amount of vanadium deposition (new catalyst reference mass %) accumulated when the new catalyst is used in the device B for a predetermined period.

Since the metal allowable amount MPr1 in the formula (1) is less than 0, the spent catalyst cannot be used in the device A. However, since the metal allowable amount MPr2 in the above formula (2) is 0 or more, the used catalyst can be used in the device B. In this way, an apparatus capable of using the spent catalyst that cannot be used in the apparatus A can be appropriately selected based on the metal permissible amount MPr2 of the catalyst. In addition, VA1 can be defined as the accumulated vanadium accumulation amount after being regenerated and used multiple times, and MPr2 can also be used for determining whether to use the catalyst after being recycled and used multiple times. On the other hand, it is not necessary to use the catalyst extracted and regenerated from the apparatus A in one apparatus B, and it can be divided and used in a plurality of apparatuses if the conditions indicated by MPr2 are satisfied.

Example

Next, although an Example demonstrates this invention in more detail, this invention is not limited at all by these Examples.

[Properties of raw material heavy oil]

The following evaluation was performed about the raw material heavy oil used for each Example and the comparative example. For the raw material heavy oil, atmospheric resid was used.

(density)

Based on JISK2249, the density of the atmospheric residual oil in 15 degreeC was measured.

(Kinematic viscosity)

Based on JIS K 2283, the kinematic viscosity of the atmospheric residual oil in 50 degreeC was measured.

(Content of residual carbon)

In accordance with JIS K2270, the content of residual coal in the atmospheric residual oil was measured.

(Content of asphaltenes)

Based on IP 143, the content of asphaltenes in the atmospheric resid was measured.

(content of sulfur)

In accordance with JIS K 2541, the content of sulfur content in the atmospheric resid was measured.

(Nitrogen content)

In accordance with JIS K2609, the nitrogen content of the atmospheric residual oil was measured.

(content of vanadium)

In accordance with the Petroleum Society Law JPI-5S-10-79, the content of vanadium in the atmospheric resid was measured.

(content of nickel)

According to the Petroleum Society Law JPI-5S-11-79, the nickel content of the atmospheric residual oil was measured.

(distillation properties)

In accordance with JIS K 2254, the distillation properties of the atmospheric resid were measured.

[Characteristics of catalyst]

The following evaluation was performed about the catalyst used for each Example and the comparative example.

For the analysis of elements such as vanadium, after calcination at 650 ° C. for 1 hour, for molybdenum and vanadium, after dissolving ash with an acid, by inductively coupled plasma emission absorption spectrometry, and for cobalt and nickel, ash and lithium tetraborate of the mixture was made into beads by high-frequency superheating, and analyzed by fluorescence X-ray analysis. 15% with respect to the carbon content (the carbon content in the catalyst is expressed as mass% of carbon in the target catalyst based on oxidation treatment of the target catalyst at 400° C. or higher until it is no longer reduced, the same applies hereinafter) or less, preferably 10% or less. The carbon content is often about 10 to 70% in the used stage, but the carbon content can be reduced by removing the carbon from the catalyst bed by regeneration treatment. When the carbon content is too large, it covers the catalyst surface and lowers the catalyst activity, but if the carbon content is reduced by a regeneration treatment, the activity can be restored. On the other hand, for the analysis of carbon and sulfur, the pulverized sample was analyzed with a C-S simultaneous analyzer. The average length of the catalyst was averaged by measuring the length in the direction perpendicular to the cross section of 10 particles randomly extracted with a vernier caliper. The average external surface area and average volume of one grain were calculated by calculation from the shape and average length of the particle cross-sectional area.

[Characteristic of Synthetic Oil]

In each Example and Comparative Example, the product oil obtained from the raw material heavy oil by the hydrorefining process was evaluated in the same manner as in the evaluation of the properties of the raw material heavy oil described above. Since the evaluation method of the properties of the product oil is the same as the evaluation method of the properties of the raw material heavy oil described above, the description of the evaluation method of the properties of the product oil is omitted.

[Preparation of new catalysts used in 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 milliliters of impregnating solution. The water content of this impregnation solution was adjusted to be suitable for the absorption amount of the following carrier, and 4,000 g of a quadrifoliate alumina carrier (specific surface area 230 m ² /g, average pore diameter 120 angstrom, pore volume 0.69 ml/g) was added. This impregnation solution was impregnated for 15 minutes. The alumina carrier impregnated with the impregnation solution was dried at 120°C for 3 hours and calcined at 500°C for 5 hours to obtain a new catalyst 1.

[Preparation of Regenerated Catalysts Used in Examples and Comparative Examples]

(Example 1)

-Hydrorefining treatment by new catalyst-

As shown in FIG. 1, the downflow fixed bed reactor is divided into 4 beds (4 equal parts by volume), and a commercially available demetal catalyst is added to the uppermost bed (referred to as “first bed”, hereinafter the same), and the remaining 3 beds. (2nd to 4th beds) was filled with the new catalyst 1. On the other hand, the physical properties and allowable amount of metal of New Catalyst 1 are shown in Table 1 below. After performing the usual preliminary sulfiding treatment, the reaction temperature is adjusted so that the sulfur content becomes constant (0.3% by mass or less) under the reaction condition 1 shown in Table 3 below using the atmospheric residual oil 1 having the properties shown in Table 2 below. The hydrorefining process was performed for 330 days while being carried out. The reaction temperature on day 330 was 396°C. The properties of the product oil 1 obtained from the atmospheric resid 1 by the hydrorefining treatment are shown in Table 4 below.

-play processing-

After washing Catalyst 1 in the reactor with light oil, drying and cooling while further circulating nitrogen gas, the spent catalyst was taken out from the second to fourth beds of the reactor and mixed well to obtain the used catalyst 1. . On the other hand, the physical properties and allowable metal amount of the used catalyst 1 are shown in Table 1 below. Thereafter, the lumps and the differentiated substances were removed from the used catalyst 1 by quarrying. Using a rotary kiln (rotational speed: 5 revolutions/minute), 100% nitrogen gas was supplied at a flow rate of 100 cc/minute to about 300 g of the used catalyst 1 from which lumps and powders were removed, and a heating temperature of 300 ° C. dried for 1 hour. After that, while supplying a mixed gas of 50% nitrogen gas and 50% air at a flow rate of 100 cc/min, calcining was performed at a calcination temperature of 450° C. for 3 hours, and after cooling the calcined used catalyst 1, the mass was divided by four minutes. And the differentiated product was removed from the used catalyst 1 to obtain a regenerated catalyst 1. The physical properties and allowable amount of metal of Regenerated Catalyst 1 are shown in Table 1 below. In addition, as the value of VA2, the value of V2 of the comparative example 1 mentioned later was used.

-Hydrorefining treatment by regeneration catalyst-

The downflow fixed bed reactor was divided into 4 beds (quarterly divided by volume), and a commercially available demetal catalyst was charged to the first bed, and regenerated catalyst 1 was charged to the second to fourth beds immediately below it. This was subjected to a normal preliminary sulfiding treatment, and then using the atmospheric residual oil 2 of the properties shown in Table 2 below, under the reaction condition 2 shown in Table 3 below, the reaction temperature so that the sulfur content became constant (0.3% by mass or less). The hydrorefining treatment was performed for 330 days while adjusting. The reaction temperature on day 330 was 398°C. The properties of product oil 2A obtained from atmospheric resid 2 by hydrorefining treatment are shown in Table 4 below. On the other hand, the downflow type fixed bed reactor is the same as that used for hydrorefining treatment with a new catalyst, but uses atmospheric resid 2, which has a lower vanadium content than atmospheric resid 1, as the raw material heavy oil, so that this reactor is used as another reactor with less vanadium deposition. can be considered as

-play processing-

In the same manner as in the regeneration treatment of the spent catalyst 1, the used regenerated catalyst 1 was regenerated to obtain a regenerated catalyst 2A. Table 1 below shows the physical properties and the allowable amount of metal of the regenerated catalyst 2A.

(Comparative Example 1)

-Hydrorefining treatment by new catalyst-

In the same manner as in Example 1, using the atmospheric resid 1 and the new catalyst 1 having properties shown in Table 2 below, hydrorefining treatment was performed under the reaction conditions 1 shown in Table 3 below.

-play processing-

In the same manner as in Example 1, the used catalyst 1 was regenerated to obtain a regenerated catalyst 1.

-Hydrorefining treatment by regeneration catalyst-

The downflow fixed bed reactor was divided into 4 beds (quarterly divided by volume), and a commercially available demetal catalyst was charged to the first bed, and regenerated catalyst 1 was charged to the second to fourth beds immediately below it. This was subjected to a normal preliminary sulfiding treatment, and then using the atmospheric residual oil 1 of the properties shown in Table 2 below, under the reaction condition 1 shown in Table 3 below, the reaction temperature so that the sulfur content became constant (0.3% by mass or less). The hydrorefining treatment was performed for 330 days while adjusting. The reaction temperature on day 330 was 408°C. The properties of the product oil 2B obtained from the atmospheric resid 1 by the hydrorefining treatment are shown in Table 4 below.

-play processing-

In the same manner as in the regeneration treatment of the spent catalyst 1, the used regenerated catalyst 1 was regenerated to obtain a regenerated catalyst 2B. The physical properties and allowable amount of metal of the regeneration catalyst 2B are shown in Table 1 below.

From the results of Example 1 and Comparative Example 1, even if it is a used catalyst whose MPr1 value is less than 0, the used catalyst can be used for a predetermined period of time by using it for another device in which the MPr2 value becomes 0 or more. could see that On the other hand, although the ratio of sulfur content in product oil 2A of Example 1 is larger than the ratio of sulfur content in product oil 2B of Comparative Example 1, the target value of sulfur content in the product oil is high in an apparatus with a low load on the catalyst. There is no problem about the use of the used catalyst of 1. On the other hand, in the spent catalyst of Comparative Example 1, a device with a high load applied to the catalyst is assumed, and the target value of sulfur content in the product oil is also low. Therefore, the properties of the product oil 2B of Comparative Example 1 are insufficient.

1: first bed
2: 2nd bed
3: 3rd bed
4: 4th bed

Claims (3)

A step of extracting a heavy oil desulfurization catalyst charged in one heavy oil desulfurization device and having a metal allowable amount MPr1 represented by the following formula (1) is less than 0;
regenerating the extracted heavy oil desulfurization catalyst;
and a step of charging the regenerated heavy oil desulfurization catalyst into at least one different heavy oil desulfurization apparatus.
MPr1 = (PV/2Vv)×{8×10 ⁵ ×(PD) ^1.3 }×(Sp/Vp)-(VA1+VA2)...(1)
In Formula (1), each symbol represents the following, respectively.
PV: Pore volume at the time of new catalyst (m ³ /kg)
Vv: The volume when 1 mass % of vanadium is deposited on 1 kg of new catalyst is regarded as vanadium sulfide = 3.8×10 ^-6 (m ³ /% kg)
PD: average pore diameter at the time of new catalyst (m)
Sp: Average external surface area of one grain at the time of new catalyst (m ² )
Vp: Average volume of 1 grain at the time of new catalyst (m ³ )
VA1: Vanadium deposition amount (mass %) accumulated in the original device (based on the new catalyst)
VA2: Vanadium deposition amount (mass %) when catalyst regenerated in the same apparatus is used (based on new catalyst) The method of claim 1,
In the step of charging the regenerated heavy oil desulfurization catalyst into at least one different heavy oil desulfurization apparatus,
A method for regenerating a heavy oil desulfurization catalyst, wherein the regenerated heavy oil desulfurization catalyst is charged in different heavy oil desulfurization devices such that the metal allowable amount MPr2 expressed by the following formula (2) is 0 or more.
MPr2 = (PV/2Vv)×{8×10 ⁵ ×(PD) ^1.3 }×(Sp/Vp)-(VA1+VB1)... (2)
In Formula (2), each symbol represents the following, respectively.
PV: Pore volume at the time of new catalyst (m ³ /kg)
Vv: The volume when 1 mass % of vanadium is deposited on 1 kg of new catalyst is regarded as vanadium sulfide = 3.8×10 ^-6 (m ³ /% kg)
PD: average pore diameter at the time of new catalyst (m)
Sp: Average external surface area of one grain at the time of new catalyst (m ² )
Vp: Average volume of 1 grain at the time of new catalyst (m ³ )
VA1: Vanadium deposition amount (mass %) accumulated in the original device (based on the new catalyst)
VB1: Vanadium deposition amount (mass %) accumulated when a catalyst regenerated in a new device is used (based on the new catalyst) 3. The method of claim 2,
A method of regenerating a heavy oil desulfurization catalyst in which different heavy oil desulfurization apparatuses are charged so that the metal allowable amount MPr2 represented by the formula (2) is 1 or more and 5 or less.

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