JP2008029944A - Hydrogenation catalyst regeneration method and diolefin purification plant - Google Patents

Abstract

The present invention provides a method for regenerating a hydrogenation catalyst without using an alkane and a diolefin purification plant equipped with simpler equipment than the conventional one used in this method.
In the method for regenerating a hydrogenation catalyst according to the present invention, by supplying nitrogen gas from a nitrogen gas injection line 29, the regeneration composition or raffinate contains nitrogen gas, and an olefin having 4 to 8 carbon atoms is obtained. The diolefin is separated from the regeneration composition containing 50% by mass or more and the inert gas-containing regeneration composition containing nitrogen gas, or the raw material composition containing at least one diolefin having 4 to 8 carbon atoms. The inert gas-containing raffinate containing the raffinate and the nitrogen gas obtained is obtained, and then the inert gas-containing regeneration composition or the inert gas-containing raffinate is brought into contact with the hydrogenation catalyst in the hydrogenation reactor 11. Let The diolefin purification plant of the present invention includes a hydrogenation catalyst regeneration facility 1 that performs the method for regenerating a hydrogenation catalyst of the present invention.
[Selection] Figure 1

Description

  The present invention relates to a hydrogenation catalyst regeneration method and a diolefin purification plant. More specifically, the present invention relates to a method for regenerating a hydrogenation catalyst used for hydrogenation and a diolefin purification plant equipped with a hydrogenation catalyst regeneration device for performing this regeneration.

  It is well known that acetylene must be removed during the diolefin purification process. The removal of acetylene is conventionally performed by selectively hydrogenating acetylene contained in the raw material composition with a hydrogenation catalyst while suppressing the influence on the diolefin.

  In this hydrogenation step, a polymer or the like is by-produced during the hydrogenation of acetylene. The polymer or the like becomes a coating for coating the catalyst, and gradually deactivates the hydrogenation catalyst. However, in industrial production where strict cost control is required, this hydrogenation catalyst must be regenerated and reused.

  Conventionally, a redox method has been used to regenerate the hydrogenation catalyst. In this method, the polymer adhering to the hydrogenation catalyst is burned off at a high temperature (for example, 400 ° C.), and then regenerated by repeatedly performing the reduction of the hydrogenation catalyst at a high temperature (for example, 200 ° C.). is there. However, in this oxidation-reduction method, (1) the problem that the life of the hydrogenation catalyst is shortened, (2) the problem that the energy cost is high due to regeneration at high temperature, and (3) oxidation and reduction at high temperature are performed. Therefore, the regenerative furnace to be used is easily damaged, the life of the furnace is shortened and the cost is increased, (4) the problem that the odor of the exhaust gas discharged from the furnace is bad and environmentally undesirable, and (5) safety. In this respect, there is a problem that is difficult to achieve.

  Techniques disclosed in the following Patent Documents 1 to 3 are known as techniques for greatly improving the above-described conventional techniques. The techniques disclosed in Patent Documents 1 and 2 below are methods for regenerating by contacting a hydrogenation catalyst with an alkane having 4 to 8 carbon atoms and hydrogen, unlike the oxidation-reduction method by high-temperature heating. Moreover, the technique disclosed in the following Patent Document 3 is a method of using an olefin as a regeneration composition and regenerating it by contacting with a hydrogenation catalyst.

JP 2001-58964 A US Pat. No. 6,512,151 International Publication WO2005 / 68078

  However, in the techniques disclosed in Patent Documents 1 and 2, (1) the problem that an expensive alkane must be used, and (2) the alkane is replaced with the raw material composition after regeneration of the hydrogenation catalyst. In this case, there are problems that the raw material composition is mixed into the alkane and it is difficult to separate the raw material composition and that loss is large, and (3) a separation facility for performing this separation is required. Therefore, the techniques disclosed in Patent Documents 1 and 2 have a problem that a relatively large plant facility having this separation facility is required. On the other hand, in the technique disclosed in Patent Document 3, an excellent regeneration effect of the hydrogenation catalyst is recognized, but currently, there is a development of a method that exhibits a regeneration effect that is even better than the technique disclosed in Patent Document 3. It is desired.

  The present invention solves the above problems. An object of the present invention is to provide a method for regenerating a hydrogenation catalyst using an olefin such as raffinate which is easy to use and a diolefin purification plant using the same.

  The present inventors have previously found that olefins can be used as a composition for regeneration, and based on this, the invention disclosed in Patent Document 3 has been completed. As a result of further improvements, the inventors have found that the regeneration efficiency of the hydrogenation catalyst can be further increased by incorporating an inert gas such as nitrogen gas into the regeneration composition, thereby completing the present invention.

That is, the present invention is as follows.
[1] A contact step of bringing a hydrogenation catalyst into contact with a regeneration composition containing 50% by mass or more of an olefin having 4 to 8 carbon atoms and an inert gas-containing regeneration composition containing an inert gas. A method for regenerating a hydrogenated catalyst.
[2] The method for regenerating a hydrogenation catalyst according to [1], wherein the regeneration composition and the inert gas are mixed to obtain the regeneration composition containing the inert gas, and then the contact step is performed.
[3] The method for regenerating a hydrogenated catalyst according to [1] or [2], wherein the content of the inert gas is 0.01 to 10 parts by mass with respect to 100 parts by mass of the regeneration composition.
[4] Contacting a hydrogenation catalyst with a raffinate obtained by separating the diolefin from a raw material composition containing at least one diolefin having 4 to 8 carbon atoms and an inert gas-containing raffinate containing an inert gas A method for regenerating a hydrogenation catalyst, comprising a contacting step.
[5] The method for regenerating a hydrogenation catalyst according to [4], wherein the raffinate and the inert gas are mixed to obtain the inert gas-containing raffinate, and then the contact step is performed.
[6] The method for regenerating a hydrogenation catalyst according to [4] or [5], wherein the content of the inert gas is 0.01 to 10 parts by mass with respect to 100 parts by mass of the raffinate.
[7] The method for regenerating a hydrogenation catalyst according to any one of [1] to [6], wherein the inert gas is one or more of nitrogen gas and rare gas.
[8] A diolefin purification plant comprising a hydrogenation catalyst regeneration facility for performing the hydrogenation catalyst regeneration method according to any one of [1] to [7].

  According to the method for regenerating a hydrogenation catalyst of the first aspect of the present invention, the regeneration efficiency of the hydrogenation catalyst can be further improved by a simple method than in the prior art. Moreover, according to the regeneration method of the hydrogenation catalyst of the first aspect of the present invention, a regeneration composition containing an inexpensive olefin can be used as the regeneration composition. As a result, the cost can be greatly reduced, and in particular, the raffinate produced as the remainder after separation of the diolefin in the purification step can be used as the above-mentioned regeneration composition.

  According to the method for regenerating a hydrogenation catalyst of the second aspect of the present invention, the regeneration efficiency of the hydrogenation catalyst can be further improved by a simple method as compared with the conventional method. Moreover, according to the method for regenerating a hydrogenation catalyst of the second aspect of the present invention, the raffinate produced as the remainder after diolefin separation in the purification step can be used. For this reason, it is not necessary to purchase or manufacture a separate regenerating composition, and the cost can be greatly reduced. Moreover, the raffinate after performing a contact process can be reused, without isolation | separation with the raw material composition mixed. Furthermore, this makes it possible to simplify the hydrogenation catalyst regeneration facility as compared with the conventional case, and to greatly reduce the plant cost.

  According to the diolefin purification plant of the present invention, the efficiency of regeneration of the hydrogenation catalyst can be further improved by a simple method than before. Moreover, according to the diolefin purification plant of this invention, the composition for reproduction | regeneration containing an cheap olefin can be used as a composition for reproduction | regeneration, and cost reduction can be performed. In particular, when the raffinate produced as the remainder after separating the diolefin in the purification step is used, the cost is greatly reduced. Moreover, the olefin of the same carbon number as the carbon number of the diolefin in a raw material composition can be used as a composition for reproduction | regeneration. For this reason, it is excellent in reusability. Further, in this case, separation from the raw material composition is not required, and the hydrogenation catalyst regeneration facility can be simplified as compared with the conventional one, and the plant cost can be reduced.

  The present invention will be described in detail below. In the present specification, “X or more” and “X or less” (“X” is an arbitrary numerical value) means that “X” is included. For example, “10 or more” includes “10”. Further, “10 or less” includes “10”.

[1] Method for Regenerating Hydrogenation Catalyst Using Regeneration Composition The method for regenerating a hydrogenation catalyst according to the first aspect of the present invention includes a regeneration composition containing 50% by mass or more of an olefin having 4 to 8 carbon atoms and an inert gas. It is characterized by comprising a contact step of bringing a hydrogenation catalyst into contact with an inert gas-containing regeneration composition containing a hydrogenated catalyst.

  The “regeneration composition” contains an olefin having 4 to 8 carbon atoms. Examples of the olefin include butene, pentene, hexene, heptene and octene. Moreover, there is no limitation in particular in the structure of the said olefin. The olefin may have a straight chain structure or a structure having a side chain. Furthermore, the position of the double bond of the olefin is not particularly limited. The said olefin may use only 1 type and may use 2 or more types together. For example, as the olefin, only one olefin (for example, only an olefin having 4 carbon atoms or only an olefin having 5 carbon atoms) can be used. Further, as the olefin, a mixture of olefins having different carbon numbers can be used. Furthermore, as each olefin, only one of the isomers may be used, or a mixture of two or more different isomers may be used.

  Examples of the butene include 1-butene and 2-butene. Examples of 1-butene include n-1-butene and iso-1-butene. On the other hand, examples of 2-butene include trans-2-butene and cis-2-butene. The butene may be a butene having a side chain or a linear butene.

  Examples of the pentene include 1-pentene, 2-pentene, and isomers thereof. The pentene may be a pentene having a side chain or a linear pentene.

  Examples of the hexene include 1-hexene, 2-hexene and 3-hexene, and further isomers thereof. The hexene may be a hexene having a side chain or a linear hexene.

  Examples of the heptene include 1-heptene, 2-heptene and 3-heptene, and further isomers thereof. The heptene may be a heptene having a side chain or a linear heptene.

  Examples of the octene include 1-octene, 2-octene, 3-octene and 4-octene, and isomers thereof. The octene may be an octene having a side chain or a linear octene.

  The total content of the olefin having 4 to 8 carbon atoms in the regeneration composition is 50% by mass or more (for example, 50 to 100% by mass), preferably 70% by mass or more with respect to the entire regeneration composition. More preferably, it is 80 mass% or more, More preferably, it is 90 mass% or more. When the total content of the olefins having 4 to 8 carbon atoms is less than 50% by mass, the regeneration effect of the hydrogenation catalyst may not be sufficiently obtained for efficient operation.

  Moreover, when there is much content of the olefin of a certain carbon number in the olefin which has 1 type of carbon number among the said C4-C8, it is easy to reuse and is convenient. Specifically, for example, the content of an olefin having one carbon number (for example, 4 or 5 carbon atoms) out of 4 to 8 carbon atoms is based on the entire olefin having 4 to 8 carbon atoms. Preferably it is 50 mass% or more (for example, 50-100 mass%), More preferably, it is 70 mass% or more, More preferably, it is 80 mass% or more, Most preferably, it is 90 mass% or more, More preferably, it is 100 mass%.

Furthermore, 4-6 are preferable and, as for carbon number of the olefin which has 1 type of carbon number among the said C4-C8, 4 or 5 is more preferable. The olefins having these carbon numbers are excellent in removal performance of a catalyst coating such as a polymer, and the separation of the catalyst coating eluted from the regeneration composition from the regeneration composition is easy. . Furthermore, the recovery composition can be easily recovered and can be operated in a mild environment (for example, 110 ° C., 25 kg / cm ² G, etc.).

  Moreover, the said composition for reproduction | regeneration may contain alkane other than the said olefin. The kind of alkane is not particularly limited. As said alkane, a C2-C10 alkane is mentioned, for example. When isomers are present in each of these, only one of the isomers of each alkane may be contained, or two or more different isomers may be contained.

  The carbon number of the alkane is not related to the carbon number of the olefin in the regeneration composition. That is, the carbon number of the alkane may be the same as or different from the carbon number of the olefin in the regeneration composition. In the present invention, an alkane having the same carbon number as that of the olefin may be contained as a main component in the balance excluding the olefin having one carbon number of 4 to 8 carbon atoms from the regeneration composition. preferable. In this case, since all or most of the contained hydrocarbons are hydrocarbons having the same carbon number, it is easy to use the same carbon number fraction, and the processing is easy because the boiling point is approximate. Furthermore, in the composition for regeneration mainly comprising an olefin having one carbon number of 4 to 8 carbon atoms, hydrocarbons having a carbon number larger than the carbon number of the main component olefin are It is preferable that it is 10 mass% or less (For example, it may be 0.1-10 mass%, More preferably, it may be 5 mass% or less, 0 mass% may be sufficient) with respect to the composition for whole.

  In addition, as described later, when the hydrogenation catalyst is a hydrogenation catalyst used for hydrogenation of an acetylenic compound contained in a raw material composition containing at least one diolefin having 4 to 8 carbon atoms. The regeneration composition preferably contains an olefin having the same carbon number as the diolefin contained in the raw material composition as a main component. When the regeneration composition contains an olefin having the same carbon number as that of the diolefin, the reusability is extremely excellent. In particular, when a raffinate obtained from a raw material composition containing a diolefin is used, the reusability is further excellent.

  For example, when the diolefin in the raw material composition contains only butadiene or the main component thereof, it is preferable that butene is the main component of the olefin in the regeneration composition. Moreover, when the diolefin in the said raw material composition has only isoprene or this as a main component, it is preferable that the olefin in the said composition for a reproduction | regeneration has pentene as a main component. In the regenerating composition, when the diolefin contained in the raw material composition is an olefin having the same carbon number as the main component, the raw material is mixed even if the raw material composition is mixed in the regenerating composition. There is no need to separate the composition, and the reusability of the recycling composition is excellent.

  Further, the regeneration composition is a case where the main component is an olefin having the same carbon number as that of the diolefin contained in the raw material composition, and the diolefin is 1,3-butadiene. In this case, it is particularly preferable that the olefin is mainly composed of at least one of iso-butene and n-butene. Furthermore, when the diolefin is isoprene, the olefin is preferably pentene having a side chain, and more preferably 1-pentene having a side chain.

  The said composition for a reproduction | regeneration should just be content of the said C4-C8 olefin 50 mass% or more (for example, 50-100 mass%). In the regeneration composition, it is preferable that the content of the olefin having 4 to 8 carbon atoms exceeds 50% by mass and the content of the alkane is less than 50% by mass. Therefore, the composition ratio of the regeneration composition is, for example, 60 to 100% by mass (more preferably 80 to 97% by mass) of the olefin having 4 to 8 carbon atoms, and 0 to 40% by mass (more preferably) of the alkane. 3 to 20% by mass), and the diolefin may be 0 to 5% by mass (more preferably 2% by mass or less).

  The acetylene content in the regeneration composition is preferably 10 ppm or less (for example, more than 0 ppm and 10 ppm or less), more preferably 5 ppm or less, still more preferably 1 ppm or less. Furthermore, the sulfur content in the regeneration composition is preferably 5 ppm or less (for example, more than 0 ppm and 5 ppm or less), more preferably 3 ppm or less, still more preferably 1 ppm or less. Therefore, the regeneration composition preferably has a sulfur content of 5 ppm or less, an acetylene content of 10 ppm or less, a sulfur content of 3 ppm or less, and an acetylene content of 5 ppm or less. It is more preferable that the sulfur content is 1 ppm or less and the acetylene content is 1 ppm or less. When the sulfur content and the acetylene content in the regeneration composition are within the above ranges, the hydrogenation catalyst can be reliably regenerated stably over a long period of time, and the quality of the diolefin which is the separation purpose can be improved. Is less affected.

The regenerating composition preferably has a low boiling point as a whole. For example, the maximum peak of boiling point at 1 atm (1.033 kg / cm ² ) of the regeneration composition {maximum peak in the correlation between temperature (horizontal axis) and fraction amount (vertical axis)} is preferably −20 to + 50 ° C. . Furthermore, the boiling point at 1 atm of the regenerating composition is preferably 50 ° C. or lower (usually −50 ° C. or higher. For example, the boiling point can be in the range of −50 to + 50 ° C.), more preferably 40. ° C or lower, more preferably 10 ° C or lower. When the maximum peak of the boiling point at 1 atm of the regeneration composition or the boiling point at 1 atm of the regeneration composition is in the above range, recovery and separation of the inert gas-containing regeneration composition can be facilitated.

  Moreover, the said composition for a reproduction | regeneration contains the 1 type or multiple types of olefin, and the composition for a reproduction | regeneration whose boiling point in 1 atm of the olefin which is the maximum content of this olefin is -20- + 50 degreeC is preferable. . By using such a regenerating composition, an olefin having a lower boiling point than that of conventionally used n-alkanes is used as a main component. Therefore, separation of the catalyst coating such as a polymer and the like from the regeneration composition is facilitated as compared with alkane. Further, the recovery composition can be recovered more easily than alkanes. Furthermore, the hydrogenation catalyst can be efficiently and reliably regenerated and can be operated in a milder environment than alkanes. The above boiling points are values at 1 atm.

  The composition for regeneration may contain a hydrocarbon other than the olefin and the alkane. Examples of the other hydrocarbons include (1) diolefins (particularly diolefins having 4 to 8 carbon atoms), olefins having 3 carbon atoms (propene), olefins having 9 or more carbon atoms, and derivatives thereof, and (2) C4-C8 olefin derivatives and the like. As said derivative | guide_body, a halogen substituted body etc. are mentioned, for example. Although there is no limitation in particular in these content, Usually, it is less than 50 mass% with respect to the said whole composition for reproduction | regeneration.

  The regenerating composition is usually a gas at normal temperature and pressure, but the properties of the regenerating composition are not particularly limited. Any of liquid, gas, and gas-liquid mixing may be sufficient as the said composition for reproduction | regeneration. The regenerating composition is preferably liquid or gas-liquid mixed. The regeneration composition can be brought close to a liquid or gas-liquid mixed state by pressurization.

  Moreover, the said composition for reproduction | regeneration can be circulated and used for using in the said contact process again after passing through the said contact process. Furthermore, the said composition for reproduction | regeneration can be mixed with the composition for reproduction | regeneration already passed through the said contact process, and can be used again in the said contact process. The inert gas-containing regeneration composition may be mixed with the raw material composition. Furthermore, you may take out the said composition for a reproduction | regeneration after passing through the said contact process.

  The inert gas is not particularly limited as long as it has a property that does not react with the regeneration composition. Specific examples of the inert gas include one or more of nitrogen gas and rare gas (such as helium gas, neon gas, and argon gas). The inert gas may be used alone or in combination of two or more. When two or more of the inert gases are used, each of the inert gases may be separately contained in the regeneration composition. Alternatively, a gas mixture containing two or more kinds of the above inert gases may be included in the above regeneration composition.

  There is no restriction | limiting in particular in content of the said inert gas, It can be made into various ranges as needed. The content of the inert gas is usually 0.01 to 10 parts by weight, preferably 0.01 to 8 parts by weight, and more preferably 0.02 to 5 parts by weight with respect to 100 parts by weight of the regeneration composition. More preferably, it is 0.02-3 mass parts, Most preferably, it is 0.05-1 mass part. It is preferable for the content of the inert gas to be in the above range since the regeneration efficiency of the hydrogenation catalyst can be increased.

  The “inert gas-containing regeneration composition” includes the regeneration composition and the inert gas. There is no particular limitation on the properties of the inert gas-containing regeneration composition. The inert gas-containing regeneration composition may be any of liquid, gas, and gas-liquid mixture. The inert gas-containing regeneration composition is preferably liquid or gas-liquid mixed. The inert gas-containing regeneration composition can be brought close to a liquid or gas-liquid mixed state by pressurizing the inert gas-containing regeneration composition.

  There is no limitation in particular in the method of obtaining the said inert gas containing regeneration composition. For example, the inert gas-containing regeneration composition can be obtained by contacting (including mixing) the regeneration composition and the inert gas. More specifically, for example, as shown in FIG. 1, during the transfer of the regeneration composition to the hydrogenation reactor containing the hydrogenation catalyst, the inert gas is introduced into the transfer line of the regeneration composition. In addition, the inert gas-containing regeneration composition can be obtained by mixing the regeneration composition and the inert gas. In addition, as described later, the above-mentioned regeneration composition containing an inert gas can be obtained by mixing the regeneration composition and the inert gas in a suitable reaction vessel.

  When the above-mentioned inert gas-containing regeneration composition is obtained, the ratio of the regeneration composition and the inert gas to be brought into contact with each other is not particularly limited, and can be set in various ranges as necessary. The ratio is usually 0.01 to 10 parts by mass, preferably 0.01 to 8 parts by mass, more preferably 0.02 to 5 parts by mass with respect to 100 parts by mass of the regenerating composition. More preferably, it is 0.02-3 mass parts, Most preferably, it is 0.05-1 mass part.

  Moreover, there is no limitation in particular also about the conditions at the time of obtaining the said inert gas containing reproduction | regeneration composition. For example, in order to increase the content of the inert gas, the inert gas and the regeneration composition are mixed by appropriately mixing the inert gas and the regeneration composition under heating and / or pressurization as necessary. A composition can be obtained. There is no limitation in particular also about the grade of the said heating and pressurization, It can be set as a various range as needed.

  The above-mentioned “hydrogenation catalyst” is a catalyst used for hydrogenation of hydrocarbons having an unsaturated bond (including aromatics, etc., usually hydrocarbons) and derivatives thereof (for example, alkyne derivatives). It is. Therefore, the hydrogenation catalyst is usually coated with a polymer produced as a by-product during the hydrogenation. An object to be hydrogenated by this hydrogenation catalyst is not particularly limited, but usually, an acetylenic compound (for example, acetylene, methylacetylene, etc.), an olefinic compound (C2-C8 olefin, etc., provided that at least one kind is used) The olefin remains). Furthermore, as said target object, the acetylenic compound contained in the said raw material composition is mentioned, for example. When the hydrogenation catalyst is a hydrogenation catalyst used for hydrogenation of the acetylenic compound contained in the raw material composition, the coating (polymer or the like) covering the hydrogenation catalyst contains an inert gas. It can be easily dissolved and removed by the regenerating composition. In addition, the said hydrogenation catalyst can be utilized for purification processes, such as diolefin.

  The hydrogenation catalyst may be a single material or a composite material. A “single substance” is a hydrogenation catalyst composed of only a component having a catalytic function (hereinafter simply referred to as “catalyst component”). The “composite” is a hydrogenation catalyst including a catalyst component and a carrier that supports the catalyst component.

  There is no limitation in particular in the kind of said catalyst component. Examples of the hydrogenation catalyst include various transition metals and compounds thereof. Examples of the various transition metals include copper, platinum, palladium, manganese, cobalt, nickel, chromium and molybdenum, and alloys thereof. Examples of the various transition metal compounds include halides (such as chlorides) of various transition metals. Among the various transition metals and compounds of various transition metals, transition metals containing at least copper and / or compounds thereof are preferable. As the hydrogenation catalyst, only one kind of various transition metals and compounds thereof may be used, or two or more kinds may be used in combination.

  The carrier is not particularly limited as long as it can carry the catalyst component. Examples of the carrier include alumina, zeolite, and silica. Further, the shape (spherical, columnar, tubular, etc.) and form (porous and non-porous, etc.) of the carrier are not particularly limited. Only 1 type may be used for the said support | carrier, and 2 or more types may be used together.

  The “contacting step” is a step of bringing the inert gas-containing regeneration composition into contact with the hydrogenation catalyst. The “contacting step” is distinguished from the step of bringing the inert gas and the regeneration composition into contact with the hydrogenation catalyst. That is, the present invention does not include a method of simply supplying the inert gas and the regeneration composition to the hydrogenation catalyst and bringing them into contact with the hydrogenation catalyst. Unlike the present invention in which the inert gas-containing regeneration composition and the hydrogenation catalyst are brought into contact with each other, the method as described above is not preferable because improvement in the regeneration efficiency of the hydrogenation catalyst is hardly recognized.

There are no particular limitations on the various conditions for the “contact”. The treatment temperature at the time of contact is preferably 50 to 200 ° C, more preferably 80 to 150 ° C, still more preferably 90 to 130 ° C. When the treatment temperature is within this range, the regeneration efficiency of the hydrogenation catalyst can be improved. The treatment pressure at the time of contact is preferably 50 kg / cm ² G or less, more preferably 40 kg / cm ² G or less, and still more preferably 30 kg / cm ² G or less. The treatment pressure is usually 5 kg / cm ² G or more. Therefore, the preferable processing pressure range is 5 to 50 kg / cm ² G. “G” in the processing pressure “kg / cm ² G” means a gauge pressure. The same applies hereinafter.

Furthermore, in the said contact process, the said process temperature and process pressure can be made into each combination. That is, for example, in the contact step, the processing temperature is preferably 50 to 200 ° C., the processing pressure is preferably 50 kg / cm ² G or less (usually 5 to 50 kg / cm ² G), and the processing temperature is 80 to 150. More preferably, the treatment pressure is 40 kg / cm ² G or less, and the treatment temperature is 90 to 130 ° C. and the treatment pressure is 30 kg / cm ² G or less. When the treatment temperature and treatment pressure are within the above ranges, the hydrogenation catalyst can be regenerated efficiently and reliably, and can be operated in a mild environment.

[2] Regeneration method of hydrogenation catalyst using raffinate For regeneration of the hydrogenation catalyst, raffinates containing olefins having 4 to 8 carbon atoms can be widely used. There is no particular limitation on the origin of the raffinate. Examples of the raffinate include raffinate obtained by petrochemical refining and natural gas refining. Especially, the raffinate obtained by isolate | separating a diolefin from the raw material composition containing at least 1 type of C4-C8 diolefin can be used.

  That is, the method for regenerating a hydrogenation catalyst according to the second aspect of the invention contains a raffinate obtained by separating the diolefin from a raw material composition containing at least one diolefin having 4 to 8 carbon atoms and an inert gas. It is characterized by comprising a contact step of bringing an inert gas-containing raffinate into contact with a hydrogenation catalyst.

  The “raw material composition” contains at least one diolefin having 4 to 8 carbon atoms. That is, for example, so-called C4 fraction, C5 fraction, C6 fraction, C7 fraction or C8 fraction. Each of these C4 to C8 fractions usually contains 80% by mass or more of a component having a predetermined carbon number contained in each fraction. That is, for example, the C4 fraction can contain 80% by mass or more of components having 4 carbon atoms (for example, butadiene, butene, butane, etc.) based on the entire C4 fraction. Among these C4 to C8 fractions, C4 to C6 fractions are preferred, and C4 and C5 fractions are particularly preferred. That is, for example, the C4 fraction contains butadiene, and the C5 fraction contains isoprene.

  The content of the diolefin contained in this raw material composition is not particularly limited. Moreover, this raw material composition contains any one diolefin having 4 to 8 carbon atoms. In particular, it is preferable that other diolefins having another carbon number are hardly contained.

  Furthermore, this raw material composition usually contains a hydrocarbon other than a diolefin having the same carbon number as that of the diolefin, or a hydrocarbon other than a diolefin having a carbon number different from that of the diolefin. These hydrocarbons include olefins and alkanes.

  Further, this raw material composition usually contains an acetylenic compound. The “acetylenic compound” is acetylene and / or a derivative thereof. This acetylenic compound is usually inevitably contained in the raw material composition, and is removed by hydrogenation and olefination before the diolefin separation step (including reducing or eliminating the concentration of the acetylenic compound). ) The content of the acetylenic compound is not particularly limited.

  The “raffinate” is a remainder obtained by separating a diolefin having 4 to 8 carbon atoms from the raw material composition. Here, the degree of the “separation” is not particularly limited. That is, the above “separation” is not only the case where the diolefin having 4 to 8 carbon atoms is completely separated from the raw material composition by the separation step, but also the diolefin having 4 to 8 carbon atoms is separated by the separation step. This includes the case where it is partially separated but still remains in the raw material composition.

  The composition of the raffinate is not particularly limited, but it is usually composed mainly of an olefin having 4 to 8 carbon atoms. Although content of this C4-C8 olefin is not specifically limited, It is preferable that it is 50 mass% or more with respect to the whole raffinate. About this olefin (a kind, content, etc.), description of the olefin in 1st this invention is applicable as it is.

  The olefin is preferably an olefin having the same carbon number as that of the diolefin contained in the raw material composition. When the raffinate contains an olefin having the same carbon number as the diolefin, the reusability is extremely excellent. In particular, when a raffinate obtained from a raw material composition containing a diolefin is used, the reusability is further excellent. In the raffinate, this is usually the same. Further, in the raffinate, the olefin having the same carbon number is usually the main component (usually 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, particularly preferably 80% by mass with respect to the entire raffinate. % Or more). This is because the raffinate is the balance of the raw material composition. Therefore, by using the raffinate, no separation is required even when the raw material composition is mixed, and for example, the raw material composition can be returned to the cracking step or the like.

  As this raffinate, for example, a raffinate in which the total content of olefins (for example, butene and the like) exceeds 50% by mass and the alkane is less than 50% by mass can be used. The raffinate has, for example, 60 to 100% by mass (more preferably 80 to 97% by mass) of olefin, 0 to 40% by mass (more preferably 3 to 20% by mass) of alkane, and 0 of diolefin. To 5% by mass (more preferably 2% by mass or less). The alkane is preferably an alkane having the same carbon number as the olefin in the raffinate.

  Furthermore, in the raffinate whose main component is an olefin having one carbon number of 4 to 8 carbon atoms, hydrocarbons having a carbon number larger than the carbon number of the main component olefin is 10 It is preferable that it is below mass% (more preferably below 5 mass%, may be 0 mass%).

  Further, the acetylene content in the raffinate is preferably 10 ppm or less (more preferably 5 ppm or less, still more preferably 1 ppm or less). Furthermore, the sulfur content in the raffinate is preferably 5 ppm or less (more preferably 3 ppm or less, still more preferably 1 ppm or less). Therefore, the sulfur content in the raffinate is preferably 5 ppm or less, the acetylene content is preferably 10 ppm or less, the sulfur content is 3 ppm or less, and the acetylene content is 5 ppm or less. More preferably, the sulfur content is 1 ppm or less, and the acetylene content is particularly preferably 1 ppm or less. When the sulfur content and acetylene content in the raffinate are in the above ranges, the hydrogenation catalyst can be reliably regenerated stably over a long period of time, and the quality of the diolefin that is the separation purpose is also affected. Little effect.

  Furthermore, although the extraction solvent used for extraction of the diolefin in the raffinate varies depending on the purification process, N-methylpyrrolidone (NMP), dimethylformamide (DMF), acetonitrile (ACN), furfural and the like are usually used. The content of these extraction solvents in the raffinate is preferably small.

  The raffinate preferably has a low boiling point as a whole. For example, the maximum peak of boiling point at 1 atm of the raffinate {maximum peak in the correlation between temperature (horizontal axis) and fraction amount (vertical axis)} is preferably -20 to + 50 ° C. Furthermore, the boiling point at 1 atm of the raffinate is preferably 50 ° C. or lower (usually -50 ° C. or higher. For example, the boiling point can be in the range of −50 to + 50 ° C.), more preferably 40 ° C. or lower. More preferably, it is 10 degrees C or less. When the maximum peak of boiling point at 1 atm of the raffinate or the boiling point at 1 atm is in the above range, the raffinate can be more easily recovered and separated.

  Moreover, when the said raffinate contains 1 type or multiple types of olefin (usually multiple types of olefin), the boiling point in 1 atm of the olefin which is the maximum content of this olefin is -20- + 50 degreeC. Is preferred. By using such a raffinate, an olefin having a lower boiling point than that of conventionally used n-alkane is used as a main component. For example, in the raffinate that is the remainder obtained by separating 1,3-butadiene from the C4 fraction, the olefin having the maximum content is usually iso-butene, and the boiling point thereof is −6.5 ° C. Moreover, in the raffinate which is the remainder which isolate | separated isoprene from C5 fraction, the olefin used as the maximum content is usually iso-pentene, and the boiling point thereof is 20.1 to 32 ° C. These are significantly lower than 69 ° C., which is the boiling point of n-hexane, which is a typical alkane disclosed in Patent Documents 1 and 2 above. For this reason, separation of a raffinate from a coating such as a polymer compound (for example, a typical coating has a boiling point of 200 ° C. at 1 atm) is easier than an alkane. In addition, the raffinate can be recovered more easily than the alkane. Furthermore, the hydrogenation catalyst can be efficiently and reliably regenerated and can be operated in a milder environment than alkanes. The above boiling points are values at 1 atm.

  The raffinate may contain a hydrocarbon other than the olefin and the alkane. Examples of the other hydrocarbons include (1) diolefins (particularly diolefins having 4 to 8 carbon atoms), olefins having 3 carbon atoms (propene), olefins having 9 or more carbon atoms, and derivatives thereof, and (2) C4-C8 olefin derivatives and the like. As said derivative | guide_body, a halogen substituted body etc. are mentioned, for example. Although there is no limitation in particular in these content, Usually, it is less than 50 mass% with respect to the said raffinate whole.

  The inert gas is not particularly limited as long as it has a property that does not react with the regeneration composition. Specific examples of the inert gas include one or more of nitrogen gas and rare gas (such as helium gas, neon gas, and argon gas). The inert gas may be used alone or in combination of two or more. When two or more of the inert gases are used, each of the inert gases may be separately contained in the raffinate. The raffinate may contain a mixed gas containing at least one kind of the inert gas.

  There is no restriction | limiting in particular in content of the said inert gas, It can be made into various ranges as needed. The content of the inert gas is usually 0.01 to 10 parts by weight, preferably 0.01 to 8 parts by weight, more preferably 0.02 to 5 parts by weight, more preferably 100 parts by weight of the raffinate. Is 0.02 to 3 parts by mass, particularly preferably 0.05 to 1 part by mass. It is preferable for the content of the inert gas to be in the above range since the regeneration efficiency of the hydrogenation catalyst can be increased.

  There is no particular limitation on the method for incorporating the inert gas into the raffinate. Examples of the method include a method of mixing the inert gas and the raffinate. There is no particular limitation on the conditions for containing the inert gas in the raffinate. In order to increase the content of the inert gas, the inert gas and the raffinate can be mixed as appropriate under heating and / or pressure. There is no limitation in particular also about the grade of the said heating and pressurization, It can be set as a various range as needed.

  The “inert gas-containing raffinate” includes the raffinate and the inert gas. There is no particular limitation on the properties of the inert gas-containing raffinate. The inert gas-containing raffinate may be any of liquid, gas, and gas-liquid mixing. The inert gas-containing raffinate is preferably liquid or gas-liquid mixed. The inert gas-containing raffinate can be brought close to a liquid or gas-liquid mixed state by pressurizing the inert gas-containing raffinate.

  There is no limitation in particular in the method of obtaining the said inert gas containing raffinate. For example, the inert gas-containing raffinate can be obtained by contacting and mixing the raffinate and the inert gas. More specifically, for example, as shown in FIG. 1, during the transfer of the raffinate to a hydrogenation reactor including the hydrogenation catalyst, the raffinate and the above are added to the raffinate transfer line by adding the inert gas. By mixing an inert gas, the inert gas-containing raffinate can be obtained. In addition, as described later, the inert gas-containing raffinate can be obtained by mixing the raffinate and the inert gas in a suitable reaction vessel.

  When the inert gas-containing raffinate is obtained, the ratio of the raffinate and the inert gas to be brought into contact with each other is not particularly limited, and can be set in various ranges as necessary. The ratio is usually 0.01 to 10 parts by mass, preferably 0.01 to 8 parts by mass, more preferably 0.02 to 5 parts by mass, more preferably 100 parts by mass of the raffinate. Is 0.02 to 3 parts by mass, particularly preferably 0.05 to 1 part by mass.

  Moreover, there is no limitation in particular also about the conditions at the time of obtaining the said inert gas containing raffinate. For example, in order to increase the content of the inert gas, the inert gas-containing raffinate can be obtained by mixing the inert gas and the raffinate under appropriate heating and / or pressurization as necessary. it can. There is no limitation in particular also about the grade of the said heating and pressurization, It can be set as a various range as needed.

  The “hydrogenation catalyst” is a catalyst used for hydrogenation of hydrocarbons having an unsaturated bond and derivatives thereof (including aliphatic and aromatic series). Therefore, the hydrogenation catalyst is usually coated with a polymer produced as a by-product during the hydrogenation. An object to be hydrogenated by the hydrogenation catalyst is not particularly limited, and examples thereof include acetylenic compounds. Furthermore, as said target object, the acetylenic compound etc. which are contained in the said raw material composition are mentioned. When the hydrogenation catalyst is a hydrogenation catalyst used for hydrogenation of the acetylenic compound contained in the raw material composition, the coating (polymer or the like) covering the hydrogenation catalyst contains an inert gas. It can be easily dissolved and removed by the regenerating composition. In addition, the said hydrogenation catalyst can be utilized for purification processes, such as diolefin.

  The hydrogenation catalyst may be a single substance composed of only a catalyst component, and the “composite” may be a composite comprising a catalyst component and a carrier supporting the catalyst component.

  There is no limitation in particular in the kind of said catalyst component. Examples of the hydrogenation catalyst include various transition metals and compounds thereof. Examples of the various transition metals include copper, platinum, palladium, manganese, cobalt, nickel, chromium and molybdenum, and alloys thereof. Examples of the various transition metal compounds include halides (such as chlorides) of various transition metals. Among the various transition metals and compounds of various transition metals, transition metals containing at least copper and / or compounds thereof are preferable. As the hydrogenation catalyst, only one kind of various transition metals and compounds thereof may be used, or two or more kinds may be used in combination.

  The carrier is not particularly limited as long as it can carry the catalyst component. Examples of the carrier include alumina, zeolite, and silica. Further, the shape (spherical, columnar, tubular, etc.) and form (porous and non-porous, etc.) of the carrier are not particularly limited. Only 1 type may be used for the said support | carrier, and 2 or more types may be used together.

  In particular, when the hydrogenation catalyst is a hydrogenation catalyst used for hydrogenation of an acetylenic compound contained in the raw material composition, raffinate can be used for regeneration of the hydrogenation catalyst in a diolefin purification plant. . As a result, the plant can be operated extremely efficiently. That is, according to this method, the raffinate that has been conventionally returned to the cracking process, used as fuel, or discarded can be used to regenerate the hydrogenation catalyst in the plant. Furthermore, the raffinate can be recycled for use in the contacting step after the contacting step. The raffinate can be reused after being mixed with the raffinate that has already undergone the contact step. Furthermore, this raffinate can also be mixed with a raw material composition and used as a raw material composition. Moreover, after passing through a contact process, this raffinate is taken out out of the system and may be used as a fuel or discarded as in the conventional case.

  For the “contacting step”, the description of the contacting step in the method for regenerating a hydrogenation catalyst of the first invention can be applied as it is.

  In the present invention, the reason why the regeneration efficiency of the hydrogenation catalyst is improved by using the inert gas-containing regeneration composition and the inert gas-containing raffinate is unknown at present. The inventor considers this reason as follows. The following explanations are all inferences made by the inventors at the present time. Therefore, the following explanation is not an absolutely correct theory, and the following explanation is not intended to define the present invention and is not intended at all.

  In general, the inert gas makes active contact between the regeneration composition or the raffinate and the hydrogenation catalyst, a polymer or the like, and as a result, it is considered that the regeneration efficiency of the hydrogenation catalyst is improved. . For example, if the hydrogenation catalyst has a large number of small holes on the surface, the small amount of clogged polymer or the like decreases the activity of the hydrogenation catalyst. In the present invention, the inert gas contained in the inert gas-containing regeneration composition or the inert gas-containing raffinate enters the small holes. And when a part of said inert gas evaporates, the partial pressure of absorption of a polymer etc. falls, As a result, a polymer etc. become easy to elute from a small hole. When the polymer or the like is eluted from the small pores, the contact between the regeneration composition or the raffinate and the hydrogenation catalyst and the polymer or the like becomes active, thereby improving the removal efficiency of the polymer or the like.

[2] Diolefin purification plant The diolefin purification plant of the present invention includes a hydrogenation catalyst regeneration facility for performing the method of regenerating a hydrogenation catalyst of the present invention.

  For example, as shown in FIG. 2, the diolefin refining plant (2) includes a hydrogenation reaction device (21) and a polymer obtained from a reaction product obtained by hydrogenation reaction in the hydrogenation reaction device (21). A polymer removal device (22) for removing water, a diolefin separation device (23) for separating diolefin from a gas component separated from the polymer removal device (22), and the like. Further, the diolefin purification plant (2) includes a hydrogenation catalyst regeneration facility for regenerating the hydrogenation catalyst charged in the hydrogenation reaction device (21) and coated with a polymer or the like by the hydrogenation reaction. (See FIG. 1).

  The hydrogenation reactor (21) requires a raw material composition containing a predetermined diolefin (for example, a C4 fraction containing butadiene or a C5 fraction containing isoprene, which contains a small amount of acetylene). Is supplied from the raw material composition supply device (24) as required, and further, hydrogen is supplied from the hydrogen supply device (25) as necessary, and is filled with the hydrogenation catalyst. This hydrogenation reactor (21) is usually provided with a plurality of groups, for example, 3 groups or 4 groups. The hydrogenation reaction device (21) is not particularly limited as long as it is a device capable of performing a hydrogenation reaction to remove an acetylenic compound, and various known devices can be used.

  The polymer removal apparatus (22) is connected to the hydrogenation reaction apparatus (21) and a pipe (26). In the polymer removal apparatus (22), the high boiling point polymer is low in hydrocarbon gas / liquid component (usually containing a large amount of desired diolefin through the pipe (27). Olefin, saturated hydrocarbon, etc. are contained.) Are separated from above through the pipe (28). The polymer removal device (22) is not particularly limited as long as it can separate a predetermined polymer to be separated and removed from a low boiling point mixture such as diolefin and monoolefin, and various known devices. Can be used.

  The diolefin separation device (23) is connected to the polymer removal device (22) by a pipe (28) and separates diolefin from a mixed gas / liquid component containing a large amount of diolefin. It is. This apparatus is not particularly limited as long as it can separate diolefins {for example, by solvent extraction (with an extraction solvent such as NMP, DMF, and ACN)}, and various known apparatuses can be used.

  The hydrogenation catalyst regeneration facility is a facility for regenerating a spent hydrogenation catalyst. The hydrogenation catalyst regeneration facility is not particularly limited as long as it is a facility capable of dissolving and removing the polymer covering the hydrogenation catalyst with a predetermined hydrocarbon component, and various known facilities can be used. . For example, as shown in FIG. 1, the hydrogenation catalyst regeneration facility (1) is filled with a used hydrogenation catalyst and the coating is dissolved in a hydrogenation reactor (11, 21 in FIG. 2). ) And a storage device (12) for the composition for regeneration (or raffinate) disposed thereafter through the pipe (16). As the hydrogenation reaction apparatus (11), the hydrogenation reaction apparatus (11) in the diolefin refining plant, which is usually filled with a used hydrogenation catalyst, is used as it is. For example, in the three hydrogenation reactors (21) in FIG. 2, one unit whose piping is indicated by a dotted line is offline. And this hydrogenation reaction apparatus (21) made offline will be used as a part of hydrogenation catalyst reproduction | regeneration equipment.

  The storage device (12) for the regeneration composition (or raffinate) is not particularly limited as long as it is a device that can store the regeneration composition (or raffinate) that dissolves the catalyst coating such as a polymer compound that is a polymer. Absent. The storage device (12) is preferably a device that stores only the regeneration composition (or raffinate) separated from the mixture containing the catalyst coating or the like and the regeneration composition (or raffinate). The storage device (12) may be a device containing both the catalyst coating and the like and the regeneration composition (or raffinate). In this case, a separation means for separating each of the storage device (12) after that. Etc. The storage device (12) may store not only the regeneration composition (or raffinate) but also the inert gas-containing regeneration composition (or inert gas-containing raffinate).

  In the hydrogenation catalyst regeneration device (1) shown in FIG. 1, the nitrogen gas injection line (29) for introducing nitrogen gas as an inert gas is the raffinate transfer line (15) in the vicinity of the hydrogenation reaction device (11). It is connected to the. In the hydrogenation catalyst regeneration device (1) shown in FIG. 1, nitrogen gas is supplied from a nitrogen gas injection line (29), and usually, the separated regeneration composition (or raffinate) contains nitrogen gas. The above inert gas-containing regeneration composition (or inert gas-containing raffinate) is obtained. Next, this inert gas-containing regeneration composition (or inert gas-containing raffinate) is introduced into the hydrogenation reactor (11) in which the catalyst coating is dissolved, and the separated gas and the like are recycled (FIG. 1). reference). Moreover, as shown in FIG. 1, this storage device (12) can be appropriately supplemented with other fresh raffinate gas (same carbon fraction).

  In the hydrogenation catalyst regeneration device (1) shown in FIG. 1, by introducing nitrogen gas through the nitrogen gas injection line (29), the above-mentioned inert gas-containing regeneration composition or inert gas-containing raffinate is obtained, This is introduced into the hydrogenation reactor (11). However, in the hydrogenation catalyst regeneration facility of the present invention, the means for obtaining the inert gas-containing regeneration composition or the inert gas-containing raffinate is not particularly limited, and various means may be adopted as necessary. it can. For example, the inert gas and the regeneration composition or the raffinate can be mixed in a suitable reaction vessel to obtain the inert gas-containing regeneration composition or the inert gas-containing raffinate. In this case, the obtained inert gas-containing regeneration composition or inert gas-containing raffinate is introduced into the hydrogenation reactor (11) through a transfer line provided separately from the raffinate transfer line (15). can do.

  Moreover, as mentioned above, when making the said inert gas contain in the said composition for a reproduction | regeneration or the said raffinate, it can heat or pressurize as needed. Therefore, the means for obtaining the above-mentioned inert gas-containing regeneration composition or inert gas-containing raffinate may have a heating or pressurizing means as necessary. Moreover, in the hydrogenation catalyst regeneration apparatus (1) shown in FIG. 1, as long as the said inert gas containing regeneration composition or an inert gas containing raffinate can be obtained, it will be in the location which provides the said nitrogen gas injection line (29). There is no particular limitation.

Hereinafter, the present invention will be described specifically by way of examples. In addition, this invention is not restrict | limited to this Example at all.
[1] Hydrogenation catalyst regeneration facility FIG. 1 is an explanatory diagram schematically showing a hydrogenation catalyst regeneration facility (1) attached to a butadiene purification plant.

This hydrogenation catalyst regeneration facility (1) has a capacity of 46 m ³ of hydrogenation containing 20 ton hydrogenation catalyst (total mass of catalyst component and carrier on which this catalyst component is supported) for hydrogenating acetylene. A reactor (11) is provided. Further, the hydrogenation catalyst regeneration facility (1) has a storage device (12) for storing raffinate. In this storage device (12), raffinate 20m ³ from which butadiene has been separated from the raw material composition is stored at a pressure of 30 kg / cm ² G. The storage device (12) is connected to the hydrogenation reaction device (11) by a raffinate transfer line (15) via a temperature control device (13) for controlling the temperature of the raffinate. Furthermore, the hydrogenation reactor (11) is connected to the storage device (11) by a raffinate return line (16) for returning the raffinate in contact with the hydrogenation catalyst in the hydrogenation reactor (11) to the storage device (12). 12). Furthermore, each of the hydrogenation reactor (11) is connected to a raw material composition transfer line (14), and the raw material composition can be flowed into the hydrogenation reactor (11) through this line. . A nitrogen gas injection line (29) for introducing nitrogen gas, which is an inert gas, is connected to the raffinate transfer line (15) in the vicinity of the hydrogenation reactor (11).

[2] Composition of raffinate The composition of raffinate stored in the storage device (12) is as follows.
Raffinate composition
iso-butane 3.18% by mass
n-butane 6.44% by mass
n-1-butene 28.12% by mass
iso-1-butene 44.18% by mass
trans-2-butene 9.22% by mass
cis-2-butene 7.46% by mass
Others 1.40% by mass
Further, the sulfur content of raffinate is 1 ppm or less, acetylene is 5 ppm or less, TBC (t-butylcatechol) is 5 ppm or less, carbonyl is 5 ppm or less, and NMP (N-methylpyrrolidone) is 5 ppm or less.

[3] Regeneration of hydrogenation catalyst The hydrogenation reaction is carried out after the raw material composition containing about 1% by mass of acetylene and the butadiene is passed through the hydrogenation reactor (11) for 4 months. The raw material composition transfer line (14) for feeding the raw material composition to the apparatus (11) is stopped. In this way, the hydrogenation catalyst coated with the polymer or the like and having reduced catalytic activity is regenerated according to the following [1] to [5].
[1] The raw material composition remaining in the hydrogenation reactor (11) and the raffinate transferred from the storage device (12) using the raffinate transfer line (15) are replaced by nitrogen pressurization.
[2] Then, using the raffinate transfer line (15) and the raffinate return line (16), the raffinate is circulated between the hydrogenation reactor (11) and the storage device (12) at a flow rate of 40 tons per hour. .
[3] Next, heating is started by the temperature control device (13) so that the temperature of the raffinate transferred to the hydrogenation reaction device (11) becomes 110 ° C. After heating, the raffinate is transferred through the raffinate transfer line (15). Then, nitrogen gas containing raffinate is obtained by introduce | transducing nitrogen gas to the said raffinate transfer line (15) with a nitrogen gas injection line (29). The nitrogen gas content in the nitrogen gas-containing raffinate is 5 parts by mass with respect to 100 parts by mass of the raffinate.
[4] The nitrogen gas-containing raffinate heated to 110 ° C. is circulated between the hydrogenation reactor (11) and the storage device (12) for 20 hours to be covered with the nitrogen gas-containing raffinate and the polymer. Contact with a hydrogenation catalyst. At this time, the treatment temperature in the hydrogenation reactor (11) is 110 ° C., and the treatment pressure is 25 kg / cm ² G.
[5] After the circulation for 20 hours, the temperature of the circulating nitrogen gas-containing raffinate is lowered to 25 ° C. by the temperature control device (13). When the entire nitrogen gas-containing raffinate reaches 25 ° C., the raffinate transfer line (15) is closed and the circulation of the nitrogen gas-containing raffinate is stopped.
[6] Thereafter, the raw material composition transfer line (14) is opened, and the nitrogen gas-containing raffinate in the hydrogenation reactor (11) is discharged using the raffinate return line (16) by nitrogen pressurization. The raw material composition is filled in the reactor (11), and the nitrogen gas-containing raffinate and the raw material composition are replaced.
[7] This reproduction process is completed in 36 hours.

[4] Effects of Examples A process for purifying butadiene from the raw material composition in the hydrogenation reactor (11) filled with the hydrogenation catalyst regenerated in [3] above is performed. As a result, the regenerated hydrogenation catalyst has good catalytic activity and can be used without any problem. That is, it can be seen that the hydrogenation catalyst can be regenerated very efficiently by the nitrogen gas-containing raffinate using the inexpensive raffinate that is the remainder obtained by separating the diolefin from the raw material composition. In the steps [3] and [6], the raw material composition is mixed in the nitrogen gas-containing raffinate. However, the nitrogen gas-containing raffinate does not need to be separated from the raw material composition, and can be used again to regenerate the hydrogenation catalyst coated with the polymer or the like in another hydrogenation reaction apparatus.

  When raffinate was used, the regeneration process was completed for 48 hours (Patent Document 3 [0048]). In contrast, in this example using the nitrogen gas-containing raffinate, the regeneration process was completed in 36 hours. That is, according to the present invention, the reproduction processing time can be reduced by 25%. This shows that the regeneration efficiency of the hydrogenation catalyst can be further improved by using a nitrogen gas-containing raffinate containing nitrogen gas which is an inert gas.

  In addition, this invention is not restricted to what is shown to said specific Example, It can be set as the Example variously changed within the range of this invention according to the objective and the use. Further, the present invention can be variously changed according to the purpose and application. For example, the contact step of the present invention may be used to regenerate a hydrogenation catalyst used in a purification step aimed at purifying a diolefin having 9 or more carbon atoms. Similarly, a hydrogenation catalyst regeneration facility used for this purpose may be provided in the plant.

  The method for regenerating a hydrogenation catalyst of the present invention is widely used for regeneration of a hydrogenation catalyst. The method for regenerating a hydrogenation catalyst of the present invention can be used particularly for regenerating a hydrogenation catalyst of an acetylenic compound. Furthermore, the method for regenerating a hydrogenation catalyst of the present invention can be used in a purification plant for diolefins (butadiene, isoprene, etc.). In the method for regenerating a hydrogenation catalyst of the present invention, when the diolefin is butadiene or isoprene, these industrially useful diolefins can be produced very efficiently and at low cost. Therefore, the method for regenerating a hydrogenation catalyst of the present invention can be suitably used in a butadiene and isoprene purification plant.

It is explanatory drawing which represented typically the hydrogenation catalyst reproduction | regeneration equipment among the diolefin refinement | purification plants of this invention. It is explanatory drawing which represented the diolefin refinement | purification plant of this invention typically.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1; Hydrogenation catalyst reproduction | regeneration equipment, 11; Hydrogenation reaction apparatus, 12; Storage apparatus, 13; Temperature control apparatus, 14; Raw material composition transfer line, 15: Raffinate transfer line, 16; Raffinate return line, 2; Refinement plant, 21; Hydrogenation reactor, 22; Polymer removal device, 23; Diolefin separation device, 24; Hydrogen supply device, 25; Raw material composition supply device, 26, 27, 28; Pipe, 29; Nitrogen gas Injection line.

Claims (8)

  It comprises a contacting step of bringing a hydrogenation catalyst into contact with a regeneration composition containing 50% by mass or more of an olefin having 4 to 8 carbon atoms and an inert gas-containing regeneration composition containing an inert gas. A method for regenerating a hydrogenation catalyst.   The method for regenerating a hydrogenated catalyst according to claim 1, wherein the regeneration composition and the inert gas are mixed to obtain the regeneration composition containing the inert gas, and then the contacting step is performed.   The method for regenerating a hydrogenation catalyst according to claim 1 or 2, wherein the content of the inert gas is 0.01 to 10 parts by mass with respect to 100 parts by mass of the regeneration composition.   Contacting step of contacting a hydrogenation catalyst with a raffinate obtained by separating the diolefin from a raw material composition containing at least one diolefin having 4 to 8 carbon atoms and an inert gas-containing raffinate containing an inert gas A method for regenerating a hydrogenation catalyst, comprising:   The method for regenerating a hydrogenated catalyst according to claim 4, wherein the raffinate and the inert gas are mixed to obtain the inert gas-containing raffinate, and then the contacting step is performed.   The method for regenerating a hydrogenation catalyst according to claim 4 or 5, wherein the content of the inert gas is 0.01 to 10 parts by mass with respect to 100 parts by mass of the raffinate.   The method for regenerating a hydrogenation catalyst according to any one of claims 1 to 6, wherein the inert gas is one or more of nitrogen gas and rare gas.   A diolefin refining plant comprising a hydrogenation catalyst regeneration facility for performing the hydrogenation catalyst regeneration method according to claim 1.

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