JP2020001028A - Processing method for content in reaction tower, extraction method for content in reaction tower, and hydrocarbon oil - Google Patents

Abstract

To provide a processing method for a content in a reaction tower applicable to the reaction towers for the wide range of petroleum fractions or petrochemical fractions and capable of easily preventing fever, firing and occurrence of noxious gas such as a sulfur-containing gas, and to provide a method for safely, efficiently extracting the content in the reaction tower, and a hydrocarbon oil.SOLUTION: There are provided a processing method for a content in a reaction tower, including a wetting process for wetting at least an outermost surface layer of the content in the reaction tower by dispersing a hydrocarbon oil from the upper part in the reaction tower; an extraction method for the content in the reaction tower including a wetting process in the processing method, a process of introducing air in the reaction tower from above to eliminate a structure in the reaction tower, and a process of extracting the content in the reaction tower; and the hydrocarbon oil used in the wetting process of the content having a prescribed aspect.SELECTED DRAWING: None

Description

  The present invention relates to a method for treating the contents of a reaction column, a method for extracting the contents of a reaction column, and a hydrocarbon oil.

  A variety of catalysts are used in a reaction tower in a petroleum refining and chemical plant, and with the decrease in the activity of the catalyst, it is necessary to perform an operation of extracting and filling the catalyst and replacing the catalyst. In the catalyst replacement work, workers enter the reaction tower, temporarily remove structures inside the reaction tower such as scale baskets, manways of distributor trays, etc., and if necessary, remain in the reaction tower. It is necessary to carry out a work for discharging the catalyst and the like, and it is extremely important to secure a safe working environment.

  For example, in a desulfurization reaction tower that performs a catalytic reaction using a catalyst in a desulfurization apparatus for various petroleum fractions, iron sulfide generated by corrosion of the apparatus on a catalyst layer filled in the reaction tower, and various types of petroleum The coke-like substance generated due to the fraction and the like is deposited, and the catalyst, iron sulfide, the coke-like substance, and the like are present. Further, when a sulfide catalyst is used as a catalyst for the desulfurization reaction, when the sulfide catalyst, iron sulfide, coke-like substance, etc. come into contact with air, the apparatus is safely stopped, and after the temperature in the reaction tower is lowered, However, it is easy to generate heat and fire, and it is easy to generate toxic gas such as sulfur-containing gas such as sulfur oxide and hydrogen sulfide. It is not an expensive task.

  Therefore, when performing a replacement operation of the catalyst of the desulfurization reaction tower in the desulfurization apparatus, the inside of the reaction tower is replaced with an inert gas such as nitrogen, and the structure inside the reaction tower is temporarily removed to easily generate heat and ignite. A method in which the contents of the reaction tower such as a catalyst, iron sulfide, and coke-like substances are discharged out of the reaction tower, and then air is introduced (hereinafter sometimes simply referred to as “conventional method”) has been generally adopted. Was. In the above conventional method, an operation such as removal of a structure inside the reaction tower is performed in the reaction tower by wearing an air line mask under a nitrogen atmosphere. However, when the air line mask comes off, an oxygen deficiency accident occurs immediately, and the air leaking from the air line mask may generate heat or ignite the contents of the reaction tower. It has been strongly demanded that safety be avoided as long as possible.

  For the purpose of responding to such a demand, Patent Document 1 discloses that a mixed liquid of a condensed ring aromatic hydrocarbon and light oil is circulated through a reaction column, and a catalyst surface and pores in the reaction column are formed. In addition, a method has been proposed in which the mixed liquid is diffused to form a film and the catalyst is extracted. Also proposed are a catalyst extraction method that circulates water or mineral oil containing lactones to infiltrate the catalyst, and a catalyst extraction method that circulates mineral oil-based hydrocarbons containing specific amines to infiltrate the catalyst. (For example, see Patent Documents 2 and 3).

JP-A-64-15127 JP-A-55-61970 JP-A-52-93677

According to the methods described in Patent Documents 1 to 3, since the used catalyst does not generate heat or ignite even if it comes into contact with air, it becomes possible to introduce air into the reaction tower, and the structure inside the reaction tower There is an advantage that the removal of the material and the removal of the catalyst can be performed safely, and the used catalyst can be easily collected. On the other hand, in these methods, it is necessary to circulate the processing liquid such as the mixed liquid used for the infiltration processing or the like via a plurality of devices, so that preparation for circulation of the processing liquid and circulating work are required. . In addition, for example, in a desulfurization apparatus such as kerosene and naphtha, there is no line for circulating the treatment liquid, so that infiltration treatment or the like cannot be performed. May not be supplied into the reaction tower, and the methods described in Patent Documents 1 to 3 have a problem that they lack versatility. That is, the application of the methods disclosed in Patent Documents 1 to 3 is currently limited to a desulfurization apparatus for a petroleum fraction having a boiling point equal to or higher than a gas oil fraction.
Therefore, the present invention is applicable to a reaction tower for a wide range of petroleum fractions, and also for petrochemical fractions derived from petrochemical production equipment such as ethylene production equipment, and generates heat, ignition, sulfur-containing gas, etc. It is an object of the present invention to provide a method for treating the contents of a reaction tower, a method for safely and efficiently extracting the contents of a reaction tower, and a hydrocarbon oil, which easily suppress generation of toxic gas.

  Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, have found that they can be solved by the following invention. That is, the present invention provides a method for treating the contents of a reaction tower, a method for extracting the contents of a reaction tower, and a hydrocarbon oil having the following constitutions.

1. A method for treating the contents of a reaction tower, comprising a wetting step of spraying hydrocarbon oil from an upper portion inside the reaction tower to wet at least the outermost layer of the contents of the reaction tower.
2. A reaction comprising a wetting step, a step of introducing air from above into the reaction tower, removing the internal structure of the reaction tower, and a step of extracting the contents of the reaction tower in the method for treating the contents of the reaction tower described in 1 above. How to extract the contents of the tower.
3. Flash point 100 ° C. or higher, 40 ° C. kinematic viscosity 2.0 mm ² / s to 60.0 mm ² / s, viscosity index 75 to 120, sulfur content 500 mass ppm or less, aromatic content (% C _A ) 10% or less And a hydrocarbon oil used for wetting the contents of the reaction tower.

  ADVANTAGE OF THE INVENTION According to this invention, it is applicable to the reaction tower of a wide range of petroleum fractions and petrochemical fractions, and a method for treating the contents of the reaction tower that easily suppresses heat generation, ignition, and generation of toxic gas such as sulfur-containing gas. It is possible to provide a safe and efficient method of extracting the contents of the reaction tower, and a hydrocarbon oil.

It is a schematic diagram which shows the cross section inside the desulfurization reaction tower in a naphtha desulfurization apparatus and a kerosene desulfurization apparatus.

(Method of treating contents of reaction tower)
A method for treating the contents of a reaction tower according to an embodiment of the present invention (hereinafter, may be simply referred to as the present embodiment) includes spraying a hydrocarbon oil from an upper portion of the inside of the reaction tower to at least the outermost layer of the contents of the reaction tower. Which has a wetting step of wetting. Hereinafter, the method for treating the contents of the reaction tower according to the present embodiment will be described in detail with reference to the drawings and the like.

  FIG. 1 (1-1) is a cross-sectional view of a desulfurization reaction tower that performs a desulfurization reaction in a naphtha desulfurization device as an example of the structure of the reaction tower in the method for treating the contents of the reaction tower according to the present embodiment. I have. In the desulfurization reaction tower 10 shown in (1-1) of FIG. 1, as a reaction tower internal structure, in order to disperse the raw material oil (mainly in a gaseous state) in the desulfurization reaction tower 10. An inlet distributor 11 is provided, and a scale basket 12 is provided as needed to collect powder such as iron sulfide and coke-like substances and to secure a flow path. In the desulfurization reaction tower 10, ceramic ball, descaling catalyst, guard catalyst, and reaction tower packing of the desulfurization catalyst are sequentially packed in layers from the top as reaction tower contents, and each of the ceramic ball packing layers (upper layer) 16a , A descaling catalyst filling layer 17, a guard catalyst filling layer 18, a desulfurization catalyst filling layer 19, and a ceramic ball filling layer (lower layer) 16b. An outlet collector using a cylindrical wire net, a structure having slits, or the like is provided below the ceramic ball packed layer (lower layer) 16b in order to prevent the reaction tower packing forming these packed layers from flowing down. (Not shown). In addition, a top elbow 13 for supplying the raw material oil to the reaction tower is provided above the desulfurization reaction tower 10, a damping nozzle 14 for extracting the catalyst and the like by its own weight is provided below the desulfurization reaction tower 10, and a desulfurization treatment is provided at the bottom. An outlet 15 for the feedstock is provided.

FIG. 1 (1-2) is a cross-sectional view of a desulfurization reaction tower that performs a desulfurization reaction in a kerosene desulfurization apparatus as an example of the structure of the reaction tower in the method for treating the contents of the reaction tower according to the present embodiment. I have. In the desulfurization reaction tower 20 shown in FIG. 1 (1-2), as a reaction tower internal structure, a raw material oil (which may be liquid or gaseous) is dispersed in the desulfurization reaction tower 20. And a distributor tray 22 provided as needed to further disperse the base oil. Further, the distributor tray 22 is provided with a manway (not shown) for various operations such as maintenance below the distributor tray 22 of the reaction tower, and for filling or extracting the reaction tower packing such as a catalyst. I have.
The desulfurization reaction tower 20 is filled with a ceramic ball, a descaling catalyst, a guard catalyst, and a reaction tower packing of a desulfurization catalyst in order from the top as a reaction tower content, and each of the desulfurization reaction towers 20 has a ceramic ball packed layer (upper layer) 26a. The descaling catalyst filling layer 27, the guard catalyst filling layer 28, the desulfurization catalyst filling layer 29, and the ceramic ball filling layer (lower layer) 26b are sequentially laminated. An outlet collector using a cylindrical wire mesh, a structure having slits, or the like is provided below the ceramic ball packed layer (lower layer) 26b to prevent the reaction tower packing forming these packed layers from flowing down. (Not shown). In addition, a top elbow 23 for supplying a raw material oil to the reaction tower is provided at an upper part of the desulfurization reaction tower 20, and a dumping nozzle 24 for extracting a catalyst or the like by its own weight is provided at a lower part of the desulfurization reaction tower 20, and at a lowermost part. An outlet 25 for the desulfurized raw oil is provided.

  Examples of the contents of the reaction tower to be treated by the method for treating the contents of the reaction tower according to the present embodiment include desulfurization catalysts filled in the reaction tower shown in (1-1) and (1-2) of FIG. Various types of catalysts, such as guard catalysts, ceramic ball, descaled catalysts, etc., reaction tower packings, and iron sulfide, coke-like, which are produced by corrosion of the reaction tower or the equipment upstream thereof and deposited on the catalyst etc. in the reaction tower Substances and the like. In other words, in the present embodiment, the contents of the reaction tower include, in addition to the reaction tower packing such as a catalyst, deposits such as iron sulfide and coke-like substances deposited in the reaction tower due to corrosion of the apparatus. It is. Here, the iron sulfide includes, in addition to the iron sulfide present as a scale (powder, layer, block), the iron sulfide adhering to a reaction tower packing such as a catalyst.

  Examples of the various catalysts include a catalyst used for a contact reaction of a petroleum fraction having a boiling point of −40 ° C. or more and 400 ° C. or less and a petrochemical fraction. For example, an LPG fraction (usually a boiling point of −40 to 10 ° C.) Petroleum fractions such as naphtha (normal boiling point about 10 to 180 ° C), kerosene (normal boiling point about 120 to 280 ° C), gas oil fraction (normal boiling point about 160 to 400 ° C), and petrochemical products such as ethylene production equipment And catalysts used for the contact reaction of petrochemical fractions originating from the production apparatus of the above. Further, as a catalyst used for the contact reaction, for example, a metal sulfide catalyst such as molybdenum sulfide or tungsten sulfide is preferably exemplified. The metal sulfide catalyst may generate toxic gas such as heat, ignition, and sulfur-containing gas by contact with air, and suppress heat generation, ignition, and generation of toxic gas such as sulfur-containing gas. The features of the processing method can be used effectively. That is, as the reaction tower in the treatment method of the present embodiment, a desulfurization reaction tower in the desulfurization apparatus for petroleum fraction is preferably exemplified.

  The method for treating the contents of the reaction tower according to the present embodiment is characterized in that the hydrocarbon oil is sprayed from the upper part of the reaction tower, and there is no need to circulate the hydrocarbon oil in the reaction tower. Therefore, the method for treating the contents of the reaction tower according to the present embodiment includes a wide range of desulfurization apparatuses for kerosene having no line to be circulated, and desulfurization apparatuses for naphtha that cannot be circulated in the reaction tower because the reaction is performed in the gas phase. The present invention can be applied to the treatment of the contents of a reaction tower in a reaction tower of a petroleum fraction or a petrochemical fraction.

  The contents of the reaction tower, such as various catalysts, iron sulfide, and coke-like substances, are likely to generate heat and fire when coming into contact with air, and toxic gases such as sulfur-containing gases such as sulfur oxides and hydrogen sulfide are easily generated. Things. In the method for treating the contents of the reaction tower according to the present embodiment, the hydrocarbon oil is sprayed from the upper part of the reaction tower to wet at least the outermost layer of the contents of the reaction tower, thereby generating heat, ignition, and toxic gas such as a sulfur-containing gas. Can be suppressed. When the hydrocarbon oil is sprayed on the contents of the reaction tower, the hydrocarbons first coat and wet the outermost layer of the contents of the reaction tower, and then flow downward (in the depth direction), Will be used to coat and wet at least a part of the reaction tower contents. The wetting by coating of the hydrocarbon oil on the contents of the reaction column covers at least a part of the surface of the contents of the reaction column while covering and moistening at least a part of the pores of the contents of the reaction column. It is thought that it becomes wet. Therefore, even if air is introduced into the reaction tower from above, the area of the contents of the reaction tower that comes into contact with air can be reduced, and heat generation, ignition, and generation of toxic gases such as sulfur-containing gases can be suppressed. It is considered to be.

In the method for treating the contents of the reaction tower according to the present embodiment, at least the outermost layer of the contents of the reaction tower is wetted with the hydrocarbon oil. The term "wet the outermost layer" is meant to include not only the top surface of the reaction tower contents but also wetting of the reaction tower contents to a depth of at least 3 cm from the top surface. Further, the contents of the reaction tower from the uppermost surface to a depth of 3 cm need only be moistened as a layer unit, and the whole surface may not be moistened by one grain unit of the reaction tower contents. It is preferable that the entire surface be moistened from the viewpoint of suppressing generation of toxic gas such as sulfur-containing gas.
In addition, from the same viewpoint, when a ceramic ball filling layer (upper layer) is provided as shown in FIGS. (1-1) and (1-2), the ceramic ball filling layer (upper layer) is located below the ceramic ball filling layer (upper layer). It is preferable to wet the contents of the reaction tower to a depth of at least 3 cm from the uppermost surface of the catalyst-packed layer (descaled catalyst-packed layer in the case of the reaction tower shown in the figure). Among the contents of the reaction tower, the ceramic ball has almost no pores unlike the catalyst, so that the hydrocarbon oil is hardly consumed for coating the ceramic ball, and most of the hydrocarbon oil is contained in the catalyst filled in the lower layer. This is because it is considered to be consumed for coating. Even if the hydrocarbon oil is not consumed for coating the ceramic ball, the surface of the ceramic ball, the iron sulfide deposited and deposited between the ceramic balls, and the cork-like substance are coated, and the ceramic ball itself is also coated. The resulting heat generation, ignition, and generation of toxic gas such as sulfur-containing gas do not occur, and the effect of suppressing heat generation, ignition, and toxic gas such as sulfur-containing gas is not impaired.

  In the method for treating the contents of the reaction tower according to the present embodiment, the contents of the reaction tower may be wetted or unwetted if the outermost layer of the reaction tower is wetted. From the viewpoint of suppressing heat generation, ignition, and generation of toxic gas such as sulfur-containing gas, it is preferable that at least a part of the contents of the lower reaction tower is moistened. The phrase "wet at least a portion" means, for example, (a) a reaction tower packing such as a ceramic ball, a catalyst, etc., one grain unit of deposits such as iron sulfide scale and a coke-like substance, and (b) a reaction tower packing. Means that a part or the whole of a layer unit formed by filling in a layer is wetted.

In the above (a), only a part of each grain may be partially moistened, only the whole may be moistened, or a part may be moistened. There may be one that has been wetted and one that has been completely wetted. Further, in the above (b), it is assumed that the content of the reaction tower, which is at least partially moistened in units of one grain, has been moistened to the lowest depth. In (b), since deposits such as iron sulfide and coke-like substances are deposited on the packed bed of the reaction tower packing such as ceramic balls and catalysts, at least a part of the packed bed is formed. If it is wet, at least part of it will naturally be wet.
In the present embodiment, in any of the above aspects, since the surface area of the contents of the reaction column in contact with air is reduced, heat generation, ignition, and generation of toxic gases such as sulfur-containing gas can be suppressed. It is.

The depth of wetting cannot be said unconditionally because it depends on the size of the reaction tower.However, from the viewpoint of obtaining a better effect of suppressing generation of toxic gases such as heat generation, ignition, and sulfur-containing gas, for example, It is preferable to wet to a depth of preferably 5 cm or more, more preferably 10 cm or more, even more preferably 15 cm or more from the uppermost surface of the contents of the reaction tower. As the upper limit of the depth, up to the lowermost layer of the contents of the reaction tower, that is, all of the contents of the reaction tower may be wetted, but in consideration of the amount of hydrocarbon oil used, heat is more efficiently generated, From the viewpoint of suppressing ignition and generation of a toxic gas such as a sulfur-containing gas, it is preferably 80 cm or less, more preferably 70 cm or less, and still more preferably 50 cm or less from the uppermost surface of the reactor contents. From the same viewpoint, when a ceramic ball packed layer (upper layer) is provided as shown in FIGS. (1-1) and (1-2), It is preferable to wet from the uppermost surface of the catalyst-packed layer (in the case of the reaction tower shown in the figure, the descaled catalyst-packed layer) to a depth in the above range.
In addition, in the case of a reaction tower having a reaction tower internal structure as shown in (1-1) of FIG. 1, in consideration of removing the reaction tower internal structure (scale basket), the depth from the bottom surface is considered. It is preferable that

The method of spraying the hydrocarbon oil is not particularly limited as long as the hydrocarbon oil can be sprayed on the contents of the reaction tower. For example, a method of spraying using a distributor tray which is an internal structure of the reaction tower, a jig such as a hose or a nozzle. Preferably, a method of spraying with the use of such a method is used. Further, the hydrocarbon oil may be sprayed in a plurality of times, for example, during the operation in the reaction tower such as the operation of removing the internal structure of the reaction tower, when the contents of the reaction tower that is not wetted is exposed. May additionally spray hydrocarbon oil.
Considering the work efficiency such as removal of the internal structure of the reaction tower performed after spraying the hydrocarbon oil, after removing the inlet distributor installed at the inlet of the feedstock, a method of spraying using a jig such as a hose or a nozzle is preferable. In a reaction tower provided with a distributor tray as an internal structure of the reaction tower, a method of spraying using the distributor tray is preferable. When a distributor tray is provided in the reaction tower, iron sulfide, coke-like substances, and the like may be deposited on the tray. Instead, it is also possible to wet iron sulfide, coke-like substances, and the like that accumulate on the tray.

  The spraying of the hydrocarbon oil is preferably performed in an atmosphere of an inert gas such as nitrogen in the reaction tower from the viewpoint of suppressing heat generation, ignition, and generation of toxic gas such as a sulfur-containing gas. In this case, the inert gas such as nitrogen may be supplied to the inside of the reaction tower from a nozzle for purging the inside of the reaction tower at the lower part of the reaction tower, or may be supplied from the upper part of the reaction tower. That is, it is preferable to spray the hydrocarbon oil while supplying an inert gas such as nitrogen into the reaction tower.

  In the present embodiment, the application of the hydrocarbon oil is simply performed by using a simple jig such as a hose from the upper part of the reaction tower or an existing structure inside the reaction tower. Therefore, according to the method for treating the contents of the reaction tower of the present embodiment, the presence or absence of a line for circulating hydrocarbon oil, a wide range of petroleum fractions regardless of the gas-liquid state of the feedstock oil in the reaction tower during operation, The present invention can be applied to a reaction tower of a petrochemical fraction and can easily treat the contents of the reaction tower. Regardless of the method of spraying the hydrocarbon oil, any of the above methods allows the worker to work from outside without entering the reaction tower, so that the inside of the reaction tower is inert gas such as nitrogen. The work is highly safe even in the atmosphere.

  In the present embodiment, from the viewpoint of easier and more efficient generation of heat, ignition, generation of toxic gas such as sulfur-containing gas, at least a part of the surface of the upper layer of the reaction tower packing from the surface in the depth direction. Is preferably wetted. By such wetting, deposits such as iron sulfide and coke-like substances which are likely to be deposited on the upper layer of the reactor packing can also be wetted at the same time, and heat, ignition, sulfur-containing gas, etc. It is possible to more efficiently suppress the generation of toxic gas.

In this embodiment, the capacity of the contents of the reaction column is not particularly limited, but is preferably 0.5 m ³ from the viewpoint of more easily and efficiently suppressing heat generation, ignition, and generation of toxic gas such as a sulfur-containing gas. or more, more preferably 1 m ³ or more. The upper limit of the capacity of the reactor contents, preferably 100 m ³ or less, more preferably 90m ³ or less. In the moistening of the contents of the reaction tower according to the treatment method of the present embodiment, there may be a case where some of the contents are not moistened, and it is necessary to collect the contents of the reaction tower by a drum instead of a simple container such as a flexible container bag. However, if the content of the reaction column is 100 m ³ or less, the load on the reaction tower can be reduced even if the content of the reaction column is recovered using a drum, which is easier. Also, spraying of the hydrocarbon oil becomes easier.

The hydrocarbon oil used in the method for treating the contents of the reaction tower according to the present embodiment may be any of mineral oil and synthetic oil.
For example, a normal pressure residual oil obtained by atmospheric distillation of paraffin-based, naphthenic-based, or intermediate-based crude oil; a distillate obtained by distilling the normal-pressure residual oil under reduced pressure; Mineral oil refined by one or more of solvent dewatering, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, etc., for example, light neutral oil, medium neutral oil, heavy oil And mineral oil obtained by isomerizing wax (GTL wax) produced by the Fischer-Tropsch method or the like.
Examples of the synthetic oil include various ester oils such as polyol ester, dibasic acid ester and phosphoric acid ester; various ethers such as polyphenyl ether; polyglycol.

  In the present embodiment, the hydrocarbon oil may be at least one kind of mineral oil, at least one kind of synthetic oil, or a mixed oil obtained by mixing at least one kind of mineral oil and at least one kind of synthetic oil. In the present embodiment, as the hydrocarbon oil, mineral oil is preferable, and paraffinic mineral oil is particularly preferable. Mineral oil is inexpensive, easy to handle, and can more easily wet the contents of the reaction tower, so that heat generation, ignition, and generation of toxic gases such as sulfur-containing gases can be more easily suppressed. .

As the properties of the hydrocarbon oil used in the treatment method of the present embodiment, it is preferable that at least the flash point, the kinematic viscosity at 40 ° C., the viscosity index, the sulfur content, and the aromatic content are in the following ranges.
The flash point is not particularly limited as long as it is higher than the temperature in the reaction tower at the time of spraying. For example, the flash point is preferably 100 ° C. or higher, more preferably 120 ° C. or higher, and even more preferably 140 ° C. or higher. If the flash point is as high as 100 ° C. or higher, handling is easy and safety is high. Here, the flash point is a value measured in accordance with JIS K 2265-4: 2007 (method of obtaining flash point, Part 4: Cleveland open method).

40 ° C. The kinematic viscosity is preferably 2.0 mm ² / s or more, more preferably 4.0 mm ² / s or more, further preferably 6.0 mm ² / s or more, upper limit is preferably 60.0 mm ² / s Or less, more preferably 50.0 mm ² / s or less, still more preferably 40.0 mm ² / s or less. When the kinematic viscosity at 40 ° C. is 2.0 mm ² / s or more, the wet state of the contents in the reaction tower is more stable. When the kinematic viscosity at 40 ° C. is 60.0 mm ² / s or less, the contents of the reaction tower can be more easily wetted.
The viscosity index is preferably at least 75, more preferably at least 80, and preferably at most 120, more preferably at most 110, as the upper limit. When the viscosity index is within the above range, the property stability of the hydrocarbon oil is high, and wetting can be performed more reliably.
Here, the kinematic viscosity at 40 ° C. and the viscosity index, and the kinematic viscosity at 100 ° C. which will be described later, are values measured according to JIS K 2283: 2000 (crude oil and petroleum products—kinematic viscosity test method and viscosity index calculation method). is there.

  From the viewpoint of further suppressing the contamination inside the reaction tower, the sulfur content is preferably as small as possible, preferably 500 ppm by mass or less, more preferably 300 ppm by mass, and still more preferably 100 ppm by mass or less, and particularly preferably 10% by mass or less. The following (sulfur-free) is preferred. Here, the sulfur content is a value measured in accordance with JIS K2541-6: 2003 (crude oil and petroleum products-sulfur content test method-part 5: ultraviolet fluorescence method).

Aromatic content, as a% C _A of ring analysis (n-d-M method), preferably 10% or less, 5% or more preferably less, more preferably 2% or less, the smaller the lower limit It is preferable that it is not particularly included. % C _A is Within the above range, is improved, especially safety. Here, the ring analysis (ndM method) is a value measured according to ASTM D3238-85.

As described above, the hydrocarbon oil used in the treatment method of the present embodiment has a flash point of 100 ° C. or more, a kinematic viscosity of 40 ° C. of 2.0 mm ² / s to 60.0 mm ² / s, and a viscosity index of 75. Preferably, the sulfur content is at most 120, the sulfur content is at most 500 mass ppm, and the aromatic content (% C _A ) is at most 10%. By using the hydrocarbon oil having such properties, the content of the reaction tower can be more reliably and efficiently moistened, and the state of the moistening of the content of the reaction column can be more stabilized. .
As the hydrocarbon oil used in the treatment method of the present embodiment, in addition to the above properties, those having the following properties, that is, those further having the following kinematic viscosity at 100 ° C, pour point, naphthene component and paraffin component are used. be able to.

The kinematic viscosity at 100 ° C. is preferably 1.0 mm ² / s or more, more preferably 1.5 mm ² / s or more, further preferably 2.0 mm ² / s or more, and preferably 10.0 mm ² / s as an upper limit. Or less, more preferably 9.0 mm ² / s or less, still more preferably 8.0 mm ² / s or less. When the kinematic viscosity at 100 ° C. is 1.0 mm ² / s or more, the wetting state of the contents of the reaction tower is more stable, and when it is 10.0 mm ² / s or less, the wetting of the contents of the reaction tower is more. It can be done easily.
It is preferable that the kinematic viscosity at 40 ° C. and the kinematic viscosity at 100 ° C. of the hydrocarbon oil be within the above ranges at the same time. At the same time, when the content is within the above range, the contents of the reaction column can be more easily wetted under a wider temperature condition.

The pour point is preferably 0.0 ° C. or lower, more preferably −2.5 ° C. or lower, and still more preferably −7.5 ° C. or lower, and the lower limit is preferably −30.0 ° C. or higher, more preferably −25 ° C. or lower. 0.0 ° C or higher, more preferably -20.0 ° C or higher. When the pour point is within the above range, the state of wetting of the contents of the reaction tower is more stable, and the contents of the reaction tower can be more easily wetted.
Here, the pour point is a value measured according to JIS K 2269: 1987 (Pour point of crude oil and petroleum products and cloud point test method of petroleum products).

Naphthene, from the viewpoint of capable of performing wetting of the reaction column contents more easily, as% C _N of ring analysis (n-d-M method), preferably 10% or more, more preferably 20% or more, further It is preferably at least 30%, and as an upper limit, it is preferably at most 50%, more preferably at most 45%. Also from the same viewpoint, the paraffin component, as a% _{C P} of the ring analysis (n-d-M method) is preferably 50% or more, more is preferably 53% or more, preferably 75% or less as the upper limit, and more Preferably it is 70% or less.

The amount of the hydrocarbon oil to be sprayed is not particularly limited, but from the viewpoint of more reliably and efficiently obtaining a better wetting state of the contents of the reaction tower, the filling in which the contents of the reaction tower in the reaction tower are filled. In the part, it is preferably 50 L or more, more preferably 100 L or more, still more preferably 200 L or more, and still more preferably 250 L or more, per 1 m ^{3 of} the volume corresponding to the depth of the filling part to be wetted. Is preferably 1000 L or less, more preferably 800 L or less, still more preferably 500 L or less, and even more preferably 400 L or less.

  The temperature (wetting temperature) in the reaction tower at the time of wetting the contents of the reaction tower is determined by adjusting the viscosity of the hydrocarbon oil to an appropriate range, from the viewpoint of efficiently wetting the contents of the reaction tower. It may be appropriately adjusted depending on the type of oil, but usually the temperature in the reaction tower is preferably 10 ° C. or higher, more preferably 15 ° C. or higher, further preferably 20 ° C. or higher, and preferably 80 ° C. or lower, Preferably it is 70 ° C. or lower, more preferably 60 ° C. or lower. In addition, when the temperature of the hydrocarbon oil is within the above range, the temperature in the reaction tower becomes appropriate, and the efficiency of subsequent operations such as removal of the internal structure of the reaction tower is improved. The temperature at the time of removing the reactor internal structure is preferably 50 ° C. or lower, more preferably 45 ° C. or lower, and further preferably 40 ° C. or lower from the viewpoint of safety.

  The time for which the hydrocarbon oil is sprayed on the contents of the reaction tower and then left (wetting time) is preferably 10 minutes from the viewpoint of more reliably and efficiently obtaining a better wet state of the contents of the reaction tower. The above is more preferably 30 minutes or more, further preferably 1 hour or more, and still more preferably 2 hours or more, and the upper limit is preferably 12 hours or less, more preferably 6 hours or less, and still more preferably 4 hours or less.

  In the method for treating the contents of the reaction tower according to the present embodiment, in addition to the above-mentioned wetting step, for example, as a preparation step of the wetting step, the temperature and pressure in the reaction tower are reduced in order to spray hydrocarbon oil more safely. Condition adjustment step in the reaction tower, inert gas introduction step to introduce an inert gas such as nitrogen into the reaction tower, top elbow connected to the feed oil supply port at the top of the reaction tower, and removal of the inlet distributor if necessary May be provided.

  The method for treating the contents of the reaction tower of the present embodiment is applicable to a wide range of reaction towers for petroleum fractions, petrochemical fractions, etc., and easily suppresses heat generation, ignition, and generation of toxic gases such as sulfur-containing gases. This is a possible processing method. Therefore, the method for treating the contents of the reaction tower of the present embodiment is suitably used, for example, in a reaction tower used for a contact reaction of a petroleum fraction and a petrochemical fraction having a boiling point of −40 ° C. or more and 400 ° C. or less. More specifically, a reaction column used for the contact reaction of petrochemical fractions derived from petrochemical fractions such as LPG fractions, gas oil fractions, petroleum fractions such as naphtha and kerosene, and petrochemical products such as ethylene production equipment. It is preferably used for, among others, a catalyst capable of generating toxic gas such as heat generation, ignition, and sulfur-containing gas by contacting with air as a reaction tower content, for example, a reaction tower equipped with a metal sulfide catalyst, a desulfurization reaction tower. It is preferably used. By employing the treatment method of the present embodiment in such a reaction tower, air can be safely introduced into the reaction tower, and various operations such as maintenance inside the reaction tower, for example, the internal structure of the reaction tower It is possible to more safely perform various operations such as maintenance, removal, etc., the operation of extracting the contents of the reaction tower such as the catalyst, and the operation of filling.

[Method of extracting contents of reaction tower]
The method of extracting the contents of the reaction tower according to the present embodiment is a wetting step in the method for treating the contents of the reaction tower of the present embodiment, a step of introducing air from above into the reaction tower, and removing the internal structure of the reaction tower. And a step of extracting the contents of the reaction tower. Since the method for extracting the contents of the reaction tower according to the present embodiment has a wetting step, it is possible to safely introduce air from above into the reaction tower. , And the step of extracting the contents of the reaction tower can be carried out more safely and efficiently.

In the method of extracting the contents of the reaction tower according to the present embodiment, the wetting step, the internal structure of the reaction tower, and the contents of the reaction tower are the same as those described in the method for treating the contents of the reaction tower of the present embodiment.
A scale basket is an example of the reactor internal structure that is extracted in the step of removing the reactor internal structure. The scale basket is arranged without a support jig in a form where the required number is bound on the packed bed of the reaction tower packing such as the catalyst. If it is withdrawn, it may descend to the vicinity of the inlet of the damping nozzle following the contents of the reaction tower, which may cause blockage. Therefore, in a reaction tower in which a scale basket is arranged, it is preferable to remove the scale basket before extracting the contents of the reaction tower. Further, the inlet distributor, the manway of the distributor tray, and the like may be removed as necessary.

  At the time of the step of removing the internal structure of the reaction tower, the contents of the reaction tower have already been moistened, so even if air is introduced into the reaction tower, heat generation, ignition, and generation of toxic gases such as sulfur-containing gas will occur. Can be suppressed. Therefore, the step of removing the internal structure of the reaction tower can be performed in an air atmosphere in the reaction tower, so that the worker can safely remove the internal structure of the reaction tower. However, it is preferable that the worker wears an air line mask in the step of removing the internal structure of the reaction tower for dust prevention measures and in consideration of safety.

  The content of the reaction tower is preferably easily and efficiently extracted from the dumping nozzle provided at the lower part of the reaction tower by its own weight, and is preferably removed after the internal structure of the reaction tower is removed. When the reaction tower is provided with a reaction tower internal structure such as a scale basket disposed above the reaction tower packing without a support jig, when the content of the reaction tower is extracted by its own weight from a damping nozzle at the lower part of the reaction tower, the inside of the reaction tower is removed. This is because it is possible to prevent the structure from following the contents of the reaction tower and descending to the vicinity of the inlet of the damping nozzle, causing blockage, and preventing the contents of the reaction tower from being quickly removed. The contents of the reaction tower can be extracted by vacuum extraction from the upper part of the reaction tower, and can be appropriately combined.

  When the contents of the reaction tower are withdrawn from the dumping nozzle provided at the lower part of the reaction tower by its own weight as described above, the contents of the reaction tower may remain at the bottom below the lower part of the reaction tower. In this case, after an appropriate amount of hydrocarbon oil is sprayed from the upper portion of the reaction tower, an operator may enter the tank into the reaction tower and perform an extraction operation or vacuum extraction.

  Since the content of the withdrawn reaction tower may include non-wetted content, it is preferable to collect the content in a drum from the viewpoint of safety. If all the contents of the reaction tower are moistened, they may be collected in a simple container such as a flexible container bag.

  The method for extracting the contents of the reaction tower according to the present embodiment includes the wetting step in the method for treating the contents of the reaction tower according to the above-described embodiment, and includes a reaction tower packing such as a catalyst, iron sulfide, and a coke-like substance. Heating, ignition, and the generation of toxic gases such as sulfur-containing gas can be suppressed by wetting the contents of the reaction tower such as sediments, etc., so that the contents of the reaction tower can be safely and efficiently extracted. It becomes possible. Therefore, the method for extracting the contents of the reaction tower of the present embodiment is suitable for, for example, extracting the contents of the reaction tower used for the contact reaction of the petroleum fraction having a boiling point of −40 ° C. or more and 400 ° C. or less, petrochemical fraction. Used for More specifically, a reaction column used for the contact reaction of petrochemical fractions derived from petrochemical fractions such as LPG fractions, gas oil fractions, petroleum fractions such as naphtha and kerosene, and petrochemical products such as ethylene production equipment. It is preferably used for extracting the contents of the reaction tower, among others, a reaction tower equipped with a catalyst capable of generating a toxic gas such as heat, ignition, and sulfur-containing gas by contact with air as the reaction tower contents, for example, a metal sulfide catalyst. It is suitably used for extracting the contents of a desulfurization reaction tower. By employing the extraction method of the present embodiment for extracting the contents of the reaction tower, various operations such as maintenance inside the reaction tower, for example, various operations such as maintenance and removal of the internal structure of the reaction tower, catalyst And the like, it is possible to introduce air into the reaction tower at the time of extracting the contents of the reaction tower, thereby providing a safer working environment for the worker.

(Hydrocarbon oil)
The hydrocarbon oil of the present embodiment has a flash point of 100 ° C. or higher, a kinematic viscosity of 40 ° C. of 2.0 mm ² / s to 60.0 mm ² / s, a viscosity index of 75 to 120, and a sulfur content of 500 mass ppm. Or less, and the aromatic content (% C _A ) is 10% or less, which is used for wetting the contents of the reaction tower. When the hydrocarbon oil has such properties, the contents of the reaction column can be more reliably and efficiently moistened, and the state of the moistening of the contents of the reaction column can be further stabilized.
The type and properties of the hydrocarbon oil are the same as those described as those that can be used in the wetting step in the method for treating the contents of the reaction tower of the present embodiment.

  Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples.

(Measurement of properties of hydrocarbon oil)
The properties of the hydrocarbon oils used in the examples and comparative examples were measured by the following methods.
(1) Flash point: Measured according to JIS K 2265-4: 2007 (Part 4: Cleveland open method).
(2) Kinematic viscosity and viscosity index: Measured according to JIS K 2283: 2000.
(3) Pour point: Measured according to JIS K 2269: 1987.
(4) Sulfur content: Measured according to JIS K2541-6: 2003 (Part 6: Ultraviolet fluorescence method).
(5) aromatics, naphthenes and paraffins content: ring analysis according to ASTM D3238-85 (n-d-M _method)% was measured by C A,% _{C N,} and% _{C P} each aromatic content , Naphthenes and paraffins.

  Table 1 below shows the properties of the hydrocarbon oils (hydrocarbon oils 1 and 2) used in the examples and the comparative examples, which were measured by the above method.

(Example 1)
After stopping the operation of the naphtha desulfurization apparatus, the temperature of the desulfurization reaction tower (see (1-1) in FIG. 1, the capacity of the reaction tower packing (catalyst): 20 m ³ ) in the apparatus is lowered to 40 ° C. After nitrogen was introduced from the lower nozzle, the top elbow and the inlet distributor connected to the upper part of the reaction tower were removed to open the upper part of the reaction tower, and nitrogen was introduced from the upper part of the reaction tower using a hose. Next, hydrocarbon oil 1 (paraffinic mineral oil) having the properties shown in Table 1 was sprayed using a hose. The spraying range is from the top surface of the packed bed of the catalyst (the top surface of the packed bed of descaled catalyst) to a depth of 500 mm in the reaction tower packing, and the spraying amount is the capacity of the 500 mm depth (3.3 m ³ ). the amount of 1 m ³ per 300L, i.e. were sprayed with hydrocarbon oil 990L.
Two hours after the end of the spraying of the hydrocarbon oil, it is assumed that the contents of the reaction tower (ceramic balls, catalyst, iron sulfide and coke-like substances) have been completely wetted, and nitrogen is introduced from the lower nozzle of the reaction tower. The operation was stopped, the introduction line of nitrogen was cut off, and the introduction of nitrogen from the top of the reaction tower was stopped by removing the hose, and the line to the reaction tower for nitrogen was completely shut off. Next, the introduction of air was started using another hose from the upper part of the reaction tower, the oxygen concentration in the upper part of the reaction tower reached 21% by volume, and sulfur oxides such as sulfur dioxide and sulfur trioxide, and sulfuric acid were detected by a gas detector. After confirming that no sulfur-containing gas such as hydrogen and no toxic gas such as carbon monoxide are generated, and that the temperature in the reaction tower is 40 ° C., a worker wearing an air line mask enters the tank, The scale basket installed at the upper part in the reaction tower was removed. Thereafter, the contents of the reaction tower were extracted by its own weight from a dumping nozzle provided at the lower part of the reaction tower, and the used catalyst and the like were extracted and collected in a drum. The contents of the reaction column remaining at the bottom of the reaction column were again sprayed with hydrocarbon oil from the upper portion of the reaction column and wetted, and then collected by an operator in a tank under an air atmosphere. When workers work inside the reaction tower, the inside of the reaction tower is in an air atmosphere, and the workers can work safely and with peace of mind.While wearing an air line mask, safety and efficiency Work was done.

(Example 2)
After stopping the operation of the kerosene desulfurization apparatus, the temperature of the desulfurization reaction tower (see (1-2) in FIG. 1; reaction tower packing (catalyst) capacity: 33 m ³ ) was lowered to 60 ° C. After nitrogen was introduced from the lower nozzle, the top elbow and the inlet distributor connected to the upper part of the reaction tower were removed to open the upper part of the reaction tower, and nitrogen was introduced from the upper part of the reaction tower using a hose. Next, hydrocarbon oil 2 (paraffinic mineral oil) having the properties shown in Table 1 was supplied to a distributor tray using a hose, and was sprayed on the contents of the reaction tower using the distributor tray. The spraying range is from the uppermost surface of the packed bed of the catalyst (the uppermost surface of the descaled catalyst packed bed) to a depth of 500 mm in the packing material of the reaction tower, and the spraying amount is the capacity (3.0 m ³ ) of the depth of 500 mm. the amount of 1 m ³ per 300L (900 L), and were sprayed with hydrocarbon oils 2100L combining the 1200L remaining on the distributor tray (hydrocarbon oil to be sprayed into packed bed of catalyst is substantially 900 L. ).
Two hours after the end of the spraying of the hydrocarbon oil, it is assumed that the contents of the reaction tower (ceramic balls, catalyst, iron sulfide and coke-like substances) have been completely wetted, and nitrogen is introduced from the lower nozzle of the reaction tower. The operation was stopped, the introduction line of nitrogen was cut off, and the introduction of nitrogen from the top of the reaction tower was stopped by removing the hose, and the line to the reaction tower for nitrogen was completely shut off. Then, the introduction of air was started using another hose from the upper part of the reaction tower, the oxygen concentration in the upper part of the reaction tower reached 21% by volume, sulfur oxides such as sulfur dioxide and sulfur trioxide, and hydrogen sulfide were detected by a gas detector. After confirming that no sulfur-containing gas such as sulfur-containing gas and no toxic gas such as carbon monoxide are generated, and that the temperature inside the reaction tower is 40 ° C., a worker wearing an air line mask enters the tank and reacts. After collecting the hydrocarbon oil, iron sulfide, coke-like substance, and the like remaining on the distributor tray installed at the upper part of the tower, the manway of the distributor tray was removed. Thereafter, the contents of the reaction tower were extracted by its own weight from a dumping nozzle provided at the lower part of the reaction tower, and the used catalyst and the like were extracted and collected in a drum. The contents of the reaction column remaining at the bottom of the reaction column were again sprayed with hydrocarbon oil from the upper portion of the reaction column and wetted, and then collected by an operator in a tank under an air atmosphere. When workers work inside the reaction tower, the inside of the reaction tower is in an air atmosphere, and the workers can work safely and with peace of mind.While wearing an air line mask, safety and efficiency Work was done.

(Comparative Example 1)
After the operation of the naphtha desulfurization unit was stopped, the temperature of the desulfurization reaction tower in the unit was lowered to 60 ° C., nitrogen was introduced from the lower nozzle of the reaction tower, and the top elbow and inlet distributor connected to the upper part of the reaction tower were removed. Then, the upper part of the reaction tower was opened, and nitrogen was introduced from the upper part of the reaction tower using a hose. After confirming that the temperature inside the reaction tower was 40 ° C., a worker wearing an air line mask entered the tank and removed the scale basket installed at the top inside the reaction tower. Although the worker wears an air line mask, the reaction tower is in a nitrogen atmosphere, and if there is a problem such as the air line mask coming off during the operation, it becomes oxygen deficient, so it is safe. Work could not be carried out with peace of mind, and work could not be carried out safely and efficiently.

10. 10. Desulfurization reaction tower in naphtha desulfurization unit Inlet distributor 12. Scale basket 13. Top elbow 14. 14. Damping nozzle Outlet 16. Ceramic ball filling layer 16a. Ceramic ball filling layer (upper layer)
16b. Ceramic ball filling layer (lower layer)
17. Descaled catalyst packed bed 18. Guard catalyst packed bed 19. Desulfurization catalyst packed bed 20. 21. Desulfurization reaction tower in kerosene desulfurization unit Inlet distributor 22. Distributor tray 23. Top elbow 24. Damping nozzle 25. Outlet 26. Ceramic ball filling layer 26a. Ceramic ball filling layer (upper layer)
26b. Ceramic ball filling layer (lower layer)
27. Descaled catalyst packed bed 28. Guard catalyst packed layer 29. Desulfurization catalyst packed bed

Claims (13)

  A method for treating the contents of a reaction tower, comprising a wetting step of spraying hydrocarbon oil from an upper portion inside the reaction tower to wet at least the outermost layer of the contents of the reaction tower. The hydrocarbon oil has a flash point of 100 ° C. or higher, a kinematic viscosity of 40 ° C. of 2.0 mm ² / s to 60.0 mm ² / s, a viscosity index of 75 to 120, a sulfur content of 500 mass ppm or less, and an aroma. processing method family fraction (% C _a) is the reaction column contents according to claim 1 is 10% or less.   The method for treating the contents of a reaction tower according to claim 1 or 2, wherein the hydrocarbon oil is sprayed using a distributor tray.   The method for treating the content of a reaction tower according to claim 1 or 2, wherein the hydrocarbon oil is sprayed using at least one jig selected from a hose and a nozzle.   The catalyst in the reaction tower is at least one selected from catalysts, iron sulfides, and coke-like substances used for the contact reaction of petroleum fractions and petrochemical fractions having a boiling point of −40 ° C. or more and 400 ° C. or less. 5. The method for treating the content of the reaction tower according to any one of 4.   The method according to claim 5, wherein the petroleum fraction is at least one selected from an LPG fraction, a gas oil fraction, naphtha and kerosene. The spray amount of the hydrocarbon oil is 50 L or more and 1000 L or less per 1 m ^{3 of} a volume corresponding to the depth of the packed portion to be wetted in the packed portion filled with the contents of the reaction tower. 7. The method for treating the contents of a reaction column according to any one of 6.   The method for treating the contents of a reaction tower according to any one of claims 1 to 7, wherein the temperature in the reaction tower is 10C or more and 80C or less. Processing method of the volume of the reaction column contents are, reactor contents according to any one of claims 1 to 8 is 0.5 m ³ or more 100 m ³ or less.   A wetting step in the method for treating contents of a reaction tower according to any one of claims 1 to 9, a step of introducing air from above into the reaction tower, and removing an internal structure of the reaction tower, and contents of the reaction tower. A method for extracting the contents of the reaction tower, comprising the step of extracting the substance.   The method according to claim 10, wherein the internal structure of the reaction tower is at least one structure selected from an inlet distributor, a scale basket, and a manway of a distributor tray. The flash point is 100 ° C. or more, the kinematic viscosity at 40 ° C. is 2.0 mm ² / s to 60.0 mm ² / s, the viscosity index is 75 to 120, the sulfur content is 500 mass ppm or less, and the aromatic content (% C _A ) a hydrocarbon oil having a content of 10% or less and used for wetting the contents of the reaction column.   The hydrocarbon according to claim 12, wherein the content of the reaction tower is at least one selected from a catalyst used for a contact reaction of a petroleum fraction and a petrochemical fraction having a boiling point of -40C to 400C and iron sulfide. oil.