JP2017210461A - Process for producing unsaturated hydrocarbons - Google Patents

Abstract

The present invention provides a method for producing unsaturated hydrocarbons that can suppress deterioration of a dehydrogenation catalyst used for producing unsaturated hydrocarbons. [Solution] A method for producing an unsaturated hydrocarbon includes a step of obtaining an unsaturated hydrocarbon by dehydrogenating at least one of an alkane and an olefin using a dehydrogenation catalyst, the dehydrogenation catalyst comprising: When the active metal is defined as at least one selected from the group consisting of platinum, ruthenium, and iridium, the total content of active metals in the dehydrogenation catalyst includes a carrier and tin supported on the carrier. is 0.0% by mass or more and less than 0.1% by mass with respect to the mass of the entire dehydrogenation catalyst. [Selection diagram] None

Description

  The present invention relates to a method for producing an unsaturated hydrocarbon.

  With recent motorization in Asia and the like, there is an increasing demand for synthetic rubber, which is a raw material for automobile parts such as tires. For example, conjugated dienes are a raw material for synthetic rubber. Therefore, an increase in demand for conjugated dienes (for example, butadiene) or unsaturated hydrocarbons (for example, n-butene) that are raw materials thereof is expected. Patent Document 1 below discloses a method for producing a conjugated diene by a direct dehydrogenation reaction of n-butane using a dehydrogenation catalyst as a method for producing a conjugated diene. Patent Documents 2 to 4 below disclose methods for producing conjugated dienes by oxidative dehydrogenation of n-butene using a dehydrogenation catalyst.

JP 2014-205135 A JP-A-57-140730 JP 60-1139 A JP 2003-220335 A

  An object of this invention is to provide the manufacturing method of the unsaturated hydrocarbon which can suppress deterioration of the dehydrogenation catalyst used for manufacture of unsaturated hydrocarbon.

  The method for producing an unsaturated hydrocarbon according to one aspect of the present invention includes a step of obtaining an unsaturated hydrocarbon by dehydrogenating at least one of an alkane and an olefin using a dehydrogenation catalyst. When the catalyst includes a support and tin supported on the support, and the active metal is defined as at least one selected from the group consisting of platinum, ruthenium and iridium, the content of the active metal in the dehydrogenation catalyst Is 0.0 mass% or more and less than 0.1 mass% with respect to the mass of the whole dehydrogenation catalyst.

  In the method for producing an unsaturated hydrocarbon according to one aspect of the present invention, a conjugated diene may be obtained as an unsaturated hydrocarbon by dehydrogenating an olefin using a dehydrogenation catalyst.

  In one aspect of the present invention, the tin content may be 5% by mass or more and 25% by mass or less based on the mass of the entire dehydrogenation catalyst.

  In one aspect of the present invention, the chlorine content may be 0.00 mass% or more and 0.01 mass% or less with respect to the mass of the entire dehydrogenation catalyst.

In one aspect of the present invention, the method for producing a dehydrogenation catalyst may include a step of impregnating a support with a first solution in which a tin source is dissolved and supporting the support with tin (Sn). The tin source may be at least one selected from the group consisting of sodium stannate (Na ₂ SnO ₃ ) and potassium stannate (K ₂ SnO ₃ ).

  In one aspect of the present invention, the first solution may be an aqueous solution.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the unsaturated hydrocarbon which can suppress deterioration of the dehydrogenation catalyst used for manufacture of unsaturated hydrocarbon is provided.

  Hereinafter, preferred embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments.

(Dehydrogenation catalyst and method for producing dehydrogenation catalyst)
The dehydrogenation catalyst according to the present embodiment includes a support and tin supported on the support. When the active metal is defined as at least one selected from the group consisting of platinum, ruthenium and iridium, the total content of the active metal in the dehydrogenation catalyst is the mass of the entire dehydrogenation catalyst in terms of element (unit). On the other hand, it is 0.0 mass% or more and less than 0.1 mass%. The dehydrogenation catalyst may not contain an active metal.

  The method for producing an unsaturated hydrocarbon according to this embodiment includes a step of obtaining an unsaturated hydrocarbon by dehydrogenating at least one of alkane and olefin using the dehydrogenation catalyst according to this embodiment. . A conjugated diene may be obtained as an unsaturated hydrocarbon by dehydrogenating an olefin using the hydrogen catalyst according to the present embodiment.

  The dehydrogenation catalyst which concerns on this embodiment is excellent in the activity which dehydrogenates each of alkane and olefin, and is especially excellent in the activity which dehydrogenates an olefin. In addition, the dehydrogenation activity of the dehydrogenation catalyst according to the present embodiment hardly deteriorates in the dehydrogenation reaction of each of alkane and olefin, and particularly hardly deteriorates in the dehydrogenation reaction of olefin. For example, the dehydrogenation catalyst according to the present embodiment is excellent in activity for producing butadiene by dehydrogenation of n-butene. And the dehydrogenation activity of the dehydrogenation catalyst which concerns on this embodiment does not deteriorate easily in the dehydrogenation reaction of n-butene.

  The method for producing a dehydrogenation catalyst according to this embodiment may include a tin supporting step. In the tin supporting step, the support may be impregnated with the first solution in which the tin source is dissolved, and the support may be supported with tin. The tin source may be at least one selected from the group consisting of sodium stannate and potassium stannate. By using sodium stannate or potassium stannate as a tin source, tin is easily dispersed in the carrier, and a large number of spaced active sites are easily formed. Therefore, the activity of the dehydrogenation catalyst is likely to be improved, and the activity of the dehydrogenation catalyst is hardly deteriorated.

  The solvent used for the first solution may be any solvent that can dissolve the tin source. The first solution may be an aqueous solution. Both sodium stannate and potassium stannate are water-soluble. Therefore, by using water as the solvent of the first solution, the tin source is easily dissolved and dispersed in the first solution. By impregnating the carrier with such a first solution, tin is easily dispersed on the surface and inside of the carrier. Moreover, by using water as a solvent, compared with the case where an organic solvent is used, the burden on the environment is reduced, and the cost is easily suppressed.

  The pH of the first solution may be 8-14 or 10-13. In the first solution having a pH within these ranges, sodium stannate or potassium stannate can be stably present in a dissolved state. In addition, by dissolving sodium stannate or potassium stannate in a predetermined amount of water, the pH of the first solution can be freely adjusted within the above range. Therefore, addition of an acid or a base is unnecessary for adjusting the pH of the first solution.

  The compounding amount of the tin source in the first solution may be appropriately adjusted according to the amount of tin supported on the carrier, the method of loading, and the like. For example, the content of tin atoms in the first solution may be 0.01% by mass or more, or 0.1% by mass or more. Moreover, 20 mass% or less or 10 mass% or less may be sufficient as content of the tin atom in a 1st solution. The supported amount of tin in the dehydrogenation catalyst may be controlled by adjusting the content of the tin source in the first solution. The supported amount of tin may be controlled by adjusting the amount (volume or mass) of the first solution impregnated in the support.

  In the tin supporting step, for example, the support may be impregnated with the first solution while removing the solvent of the first solution with an evaporator or the like.

  The carrier impregnated with the first solution may be dried or calcined. What is necessary is just to adjust the conditions of drying suitably according to the solvent of a 1st solution. A calcination temperature may be 300-900 degreeC or 400-800 degreeC, for example. The firing time may be, for example, 1 to 10 hours, or 2 to 5 hours.

  The support may be an inorganic oxide. The inorganic oxide may be at least one selected from the group consisting of alumina, alumina magnesia, magnesia, titania, silica, silica alumina, silica magnesia, ferrite, and spinel structure. The spinel structure may be at least one selected from the group consisting of, for example, magnesium spinel, iron spinel, zinc spinel, and manganese spinel.

  It is relatively preferable that the support contains aluminum (Al). In other words, it is relatively preferable that the support contains alumina. The content of Al (aluminum atom) in the support may be 25% by mass or more, or 50% by mass or more with respect to the mass of the entire support.

The support may include magnesium spinel (MgAl ₂ O ₄ ), which is a spinel structure. Since the acidity of the support containing magnesium spinel is relatively small, the deposition of coke (carbon) associated with the dehydrogenation reaction is easily suppressed.

  In this embodiment, after the tin is supported on the support in the tin supporting step, the following active metal supporting step may be performed. That is, the method for producing a dehydrogenation catalyst according to this embodiment may further include an active metal supporting step. After the active metal is supported on the support in the following active metal supporting step, the above tin supporting step may be performed.

  In the active metal loading step, the support may be loaded with the active metal by impregnating the carrier with the second solution in which the active metal source is dissolved. However, in the active metal supporting step, the amount of active metal supported is adjusted so that the total content of active metals in the dehydrogenation catalyst is less than 0.1% by mass with respect to the total mass of the dehydrogenation catalyst. . The active metal source has at least one active metal selected from the group consisting of platinum, ruthenium and iridium.

  The method for producing a dehydrogenation catalyst according to the present embodiment may not further include an active metal supporting step. When not performing an active metal carrying | support process, the sum total of content of the active metal in a dehydrogenation catalyst may be 0.0 mass% with respect to the mass of the whole dehydrogenation catalyst.

  The active metal source may be at least one selected from the group consisting of a platinum source, a ruthenium source, and an iridium source.

  The platinum source may be a compound containing platinum and not containing a chlorine atom. Platinum sources include, for example, tetraammineplatinum (II) acid, tetraammineplatinum (II) acid salt (eg, nitrate), tetraammineplatinum (II) acid hydroxide solution, dinitrodiammineplatinum (II) nitric acid solution, hexahydroxoplatinum It may be at least one selected from the group consisting of (IV) acid nitric acid solution and hexahydroxoplatinum (IV) acid ethanolamine solution.

  The ruthenium source may be a compound containing ruthenium and not containing a chlorine atom. The ruthenium source may be at least one selected from the group consisting of ruthenium (III) nitrate, sodium ruthenium (IV) acid, and potassium ruthenium (IV) acid, for example.

  The iridium source may be a compound containing iridium and not containing a chlorine atom. The iridium source may be at least one selected from the group consisting of, for example, iridium (IV) nitrate and hexaneammineiridium (III) hydroxide solution.

  The solvent used for the second solution may be any solvent that can dissolve the active metal source. The solvent in the second solution may be water or ethanol, for example.

  The compounding amount of the active metal source in the second solution may be appropriately adjusted according to the amount of the active metal supported on the carrier, the supporting method, and the like. For example, the content of the active metal in the second solution may be 0.01% by mass or more, or 0.1% by mass or more. Moreover, 10 mass% or less or 5 mass% or less may be sufficient as content of the active metal in a 2nd solution. The amount of active metal supported in the dehydrogenation catalyst may be controlled by adjusting the content of the active metal source in the second solution. The amount of the active metal supported may be controlled by adjusting the amount (volume or mass) of the second solution impregnated on the support.

  In the active metal supporting step, for example, the support may be impregnated with the second solution while removing the solvent of the second solution with an evaporator or the like.

  The carrier impregnated with the second solution may be dried or calcined. What is necessary is just to adjust the conditions of drying suitably according to the solvent of a 2nd solution. A calcination temperature may be 200-700 degreeC or 300-600 degreeC, for example. The firing time may be, for example, 1 to 10 hours, or 2 to 5 hours. When the active metal source contains ruthenium, it is preferable that the carrier impregnated with the second solution is fired under a nitrogen flow.

  The tin source used in the tin loading process should not contain chlorine. The active metal source used in the active metal loading step should also contain no chlorine. In other words, the platinum source, ruthenium source and iridium source should all have no chlorine atom. None of the specific examples of the tin source, the platinum source, the ruthenium source, and the iridium source contain a chlorine atom. When both the tin source and the active metal source do not contain a chlorine atom, a dehydrogenation catalyst having a remarkably low chlorine (chlorine atom) content or a chlorine-free dehydrogenation catalyst is obtained. When the dehydrogenation catalyst contains chlorine, hydrochloric acid is easily generated in the dehydrogenation reaction of alkane or olefin in the presence of water. This hydrochloric acid corrodes the reactor (especially a metallic reactor). On the other hand, when a dehydrogenation catalyst with extremely low chlorine (chlorine atom) content or a dehydrogenation catalyst that does not contain chlorine is used, the formation of hydrochloric acid in the dehydrogenation reaction is suppressed, and the reactor is sufficiently corroded by hydrochloric acid. It is suppressed. The chlorine content in the dehydrogenation catalyst may be 0.00 mass% or more and 0.01 mass% or less with respect to the mass of the entire dehydrogenation catalyst in terms of elements. When the chlorine content is 0.01% by mass or less, the formation of hydrochloric acid is easily suppressed, and the corrosion of the reactor by hydrochloric acid is also easily suppressed.

(Method for producing unsaturated hydrocarbons using dehydrogenation catalyst)
As described above, in the method for producing an unsaturated hydrocarbon according to the present embodiment, at least one of the alkane and the olefin is dehydrogenated using the dehydrogenation catalyst according to the present embodiment. By this dehydrogenation step, an unsaturated hydrocarbon that is at least one selected from the group consisting of olefins and conjugated dienes is obtained.

  When alkane is used as a raw material, the content (supported amount) of tin in the dehydrogenation catalyst is, for example, 1% by mass or more and 1.3% by mass in terms of element (unit) with respect to the total mass of the dehydrogenation catalyst. As mentioned above, it may be 9 mass% or less, or 7 mass% or less. When the content of tin is within the above range, the dehydrogenation ability of the dehydrogenation catalyst with respect to alkane is easily improved. In addition, when the tin content is within the above range, coke deposition due to alkane dehydrogenation is easily suppressed, and deterioration of the dehydrogenation catalyst is easily suppressed. That is, the life of the dehydrogenation catalyst tends to be extended.

  When olefin is used as a raw material, the content of tin in the dehydrogenation catalyst is, for example, 5% by mass or more and 25% by mass or less, or 7% by mass or more and 18% by mass or less with respect to the total mass of the dehydrogenation catalyst. Good. When the content of tin is within the above range, the dehydrogenation ability of the dehydrogenation catalyst with respect to olefin is easily improved. Moreover, when content of tin exists in said range, precipitation of the coke accompanying olefin dehydrogenation is easy to be suppressed, and deterioration of a dehydrogenation catalyst is easy to be suppressed. That is, the life of the dehydrogenation catalyst is likely to be extended. In particular, when the tin content is 25% by mass or less with respect to the total mass of the dehydrogenation catalyst, tin is easily supported on the support, and coke precipitation due to olefin dehydrogenation is easily suppressed. Degradation of the dehydrogenation catalyst is easily suppressed.

  As above-mentioned, the sum total of content of the active metal in a dehydrogenation catalyst is 0.0 to 0.1 mass% with respect to the mass of the whole dehydrogenation catalyst. The dehydrogenation catalyst may not contain an active metal. Since the content of the active metal in the dehydrogenation catalyst according to this embodiment is less than 0.1% by mass, the dehydrogenation activity of the dehydrogenation catalyst according to this embodiment is compared with the activity of the conventional dehydrogenation catalyst. , Hard to deteriorate. The present inventors consider that the reason why the dehydrogenation activity of the dehydrogenation catalyst is less likely to deteriorate as the content of the active metal is smaller is as follows. As the content of the active metal in the dehydrogenation catalyst is smaller, the deposition of coke accompanying the dehydrogenation reaction is suppressed, and the active metal is also prevented from being coated with the coke. As a result, rapid deterioration of activity due to coke hardly occurs. However, the mechanism by which the degradation of the dehydrogenation activity is suppressed is not limited to the above. In the dehydrogenation catalyst, the active metal and tin may interact, for example, may form an alloy.

  The contents (supported amounts) of tin and active metals in the dehydrogenation catalyst may be measured, for example, by high frequency inductively coupled plasma (ICP) emission spectroscopy. In the measurement, for example, a sample solution is sprayed and introduced into Ar plasma, and when the element excited in Ar plasma returns to the ground state, the light emitted from the element is dispersed, and the element is identified from the wavelength of the emitted light. The element is quantified from the intensity of the emitted light.

  After the dehydrogenation catalyst is subjected to a reduction treatment, the dehydrogenation catalyst may be used for the dehydrogenation reaction. In the reduction treatment, for example, the dehydrogenation catalyst may be held in a reducing gas at 40 to 600 ° C. The holding time may be, for example, 0.05 to 24 hours. The reducing gas may be, for example, hydrogen or carbon monoxide.

[Dehydrogenation of alkane]
In the dehydrogenation step, for example, a raw material gas containing alkane may be brought into contact with a dehydrogenation catalyst to obtain a product gas containing unsaturated hydrocarbons.

  The carbon number of the alkane may be the same as the carbon number of the target unsaturated hydrocarbon. That is, the alkane may be a saturated hydrocarbon obtained when a double bond existing in the target unsaturated hydrocarbon is hydrogenated. The carbon number of the alkane may be, for example, 3 to 10 or 3 to 6.

  The alkane may be, for example, a chain or a ring. The chain alkane may be at least one selected from the group consisting of propane, butane, pentane, hexane, heptane, octane, and decane, for example. The chain alkane may be linear or branched. The linear alkane may be at least one selected from the group consisting of n-butane, n-pentane, n-hexane, n-heptane, n-octane, and n-decane, for example. The branched alkane may be at least one selected from the group consisting of isobutane, isopentane, 2-methylpentane, 3-methylpentane, 2,3-dimethylpentane, isoheptane, isooctane, and isodecane, for example. The cyclic alkane may be at least one selected from the group consisting of cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, and methylcyclohexane, for example. The source gas may contain one kind of alkane or two or more kinds of alkane.

  The partial pressure of alkane in the source gas may be, for example, 1.0 MPa or less, 0.1 MPa or less, or 0.01 MPa or less. By reducing the partial pressure of the alkane in the raw material gas, the deterioration of the dehydrogenation catalyst is easily suppressed, and the alkane is easily converted to an unsaturated hydrocarbon.

  Further, the partial pressure of alkane in the raw material gas may be 0.001 MPa or more, or 0.005 MPa or more from the viewpoint of reducing the ratio of the capacity of the reactor to the flow rate of the raw material gas.

  The source gas may further contain an inert gas such as nitrogen or argon.

  The source gas may further contain steam (water). When the source gas contains steam, deterioration of the activity of the dehydrogenation catalyst may be suppressed. The number of moles of steam contained in the source gas may be, for example, 1.0 times or more, or 1.5 times or more of the number of moles of alkane. The number of moles of steam contained in the source gas may be, for example, 50 times or less, or 10 times or less the number of moles of alkane.

  The source gas may further contain other components such as hydrogen, oxygen, carbon monoxide, carbon dioxide gas, olefins and dienes in addition to the above components.

  The product gas obtained by hydrogenation of the raw material gas contains at least one unsaturated hydrocarbon selected from the group consisting of olefins and conjugated dienes. The number of carbon atoms of the olefin and conjugated diene may be the same as the carbon number of the alkane, for example, 4 to 10 or 4 to 6.

  The olefin may be at least one selected from the group consisting of butene, pentene, hexene, heptene, octene, nonene, and decene, for example. The unsaturated hydrocarbon may be an isomer of any of these olefins. Conjugated dienes are, for example, 1,3-butadiene, 1,3-pentadiene, isoprene, 1,3-hexadiene, 1,3-heptadiene, 1,3-octadiene, 1,3-nonadiene, and 1,3-decadiene. It may be at least one selected from the group consisting of The product gas may contain one type of unsaturated hydrocarbon, and may contain two or more types of unsaturated hydrocarbons. For example, the product gas may include olefins and conjugated dienes.

  In the dehydrogenation step, for example, the raw material gas may be circulated in the reactor filled with the dehydrogenation catalyst. The reactor may be a variety of reactors used for gas phase reactions with solid catalysts. The reactor may be, for example, a fixed bed reactor, a radial flow reactor, or a tubular reactor.

  The reaction type of the dehydrogenation reaction may be, for example, a fixed bed type, a moving bed type, or a fluidized bed type. Among these, the fixed bed type is preferable in terms of low equipment cost.

  The reaction temperature of the dehydrogenation reaction may be 300 to 800 ° C or 500 to 700 ° C from the viewpoint of reaction efficiency. If reaction temperature is 500 degreeC or more, the production amount of unsaturated hydrocarbon will increase easily. If reaction temperature is 700 degrees C or less, since the speed of coking does not become large too much, the high activity of a dehydrogenation catalyst is easy to be maintained over a long period of time. The reaction temperature may be rephrased as the temperature in the reactor or the temperature of the dehydrogenation catalyst.

  The reaction pressure (that is, the atmospheric pressure in the reactor) may be 0.01 to 1 MPa, 0.05 to 0.8 MPa, or 0.1 to 0.5 MPa. When the reaction pressure is in the above range, the dehydrogenation reaction is likely to proceed, and further excellent reaction efficiency is easily obtained.

In the dehydrogenation process, when supplying the raw material gas into the reactor continuously, a weight hourly space velocity (WHSV) is, 0.1 h ^-1 or more, 1.0 h ^-1 or more, 100h ^-1 or less, or ^{30h -1} The mass of the dehydrogenation catalyst charged in the continuous reactor, which may be the following, is W, and the mass (feed amount / hour) of the raw material gas fed into the reactor per hour is F. At some point, WHSV is expressed in F / W. In addition, the usage-amount of each of source gas and a dehydrogenation catalyst may be suitably adjusted according to reaction conditions or the activity of a dehydrogenation catalyst. WHSV is not limited to the above range.

[Dehydrogenation of olefins]
In the dehydrogenation step, for example, a raw material gas containing olefin may be brought into contact with a dehydrogenation catalyst to obtain a product gas containing unsaturated hydrocarbons. For example, a product gas containing a conjugated diene may be obtained as an unsaturated hydrocarbon by bringing a raw material gas containing an olefin into contact with a dehydrogenation catalyst.

  The carbon number of the olefin may be the same as the carbon number of the target conjugated diene. That is, the olefin may be a hydrocarbon compound obtained when one of the double bonds present in the target conjugated diene is hydrogenated. The number of carbon atoms of the olefin may be, for example, 4 to 10 or 4 to 6.

  The olefin may be, for example, linear or cyclic. The chain olefin may be at least one selected from the group consisting of butene, pentene, hexene, heptene, octene, nonene and decene, for example. The chain olefin may be linear or branched. The linear olefin may be at least one selected from the group consisting of n-butene, n-pentene, n-hexene, n-heptene, n-octene, n-nonene and n-decene, for example. The branched olefin may be at least one selected from the group consisting of isopentene, 2-methylpentene, 3-methylpentene, 2,3-dimethylpentene, isoheptene, isooctene, isononene, and isodecene, for example. The raw material gas may contain one kind of olefin, and may contain two or more kinds of olefins.

  The partial pressure of the olefin in the raw material gas may be, for example, 1.0 MPa or less, 0.1 MPa or less, or 0.01 MPa or less. By reducing the partial pressure of the olefin in the raw material gas, the deterioration of the dehydrogenation catalyst is easily suppressed, and the olefin is easily converted to an unsaturated hydrocarbon.

  Further, the partial pressure of olefin in the raw material gas may be 0.001 MPa or more, or 0.005 MPa or more from the viewpoint of reducing the ratio of the reactor capacity to the flow rate of the raw material gas.

  The source gas may further contain an inert gas such as nitrogen or argon.

  The source gas may further contain steam. When the source gas contains steam, deterioration of the activity of the dehydrogenation catalyst may be suppressed. The number of moles of steam contained in the source gas may be, for example, 1.0 times or more, or 1.5 times or more of the number of moles of olefin. The number of moles of steam contained in the raw material gas may be, for example, 50 times or less, or 10 times or less the number of moles of olefin.

  The source gas may further contain other components such as hydrogen, oxygen, carbon monoxide, carbon dioxide gas, alkanes and dienes in addition to the above components.

  Conjugated dienes obtained in the dehydrogenation step are, for example, butadiene (1,3-butadiene), 1,3-pentadiene, isoprene, 1,3-hexadiene, 1,3-heptadiene, 1,3-octadiene, 1,3. -It may be at least one selected from the group consisting of nonadiene and 1,3-decadiene. The product gas may contain one kind of conjugated diene or two or more kinds of conjugated dienes.

  In the dehydrogenation step, for example, the raw material gas may be circulated in the reactor filled with the dehydrogenation catalyst. The reactor may be a variety of reactors used for gas phase reactions with solid catalysts. The reactor may be, for example, a fixed bed reactor, a radial flow reactor, or a tubular reactor.

  The reaction type of the dehydrogenation reaction may be, for example, a fixed bed type, a moving bed type, or a fluidized bed type. Among these, the fixed bed type is preferable in terms of low equipment cost.

  The reaction temperature of the dehydrogenation reaction may be 300 to 800 ° C, 400 to 700 ° C, or 500 to 650 ° C from the viewpoint of reaction efficiency. If reaction temperature is 300 degreeC or more, since the equilibrium conversion rate of an olefin is not too low, the yield of a conjugated diene is easy to improve further. If reaction temperature is 800 degrees C or less, since the coking speed | rate is not too large, the high activity of a dehydrogenation catalyst is easy to be maintained over a long period of time. The reaction temperature may be rephrased as the temperature in the reactor or the temperature of the dehydrogenation catalyst.

  The reaction pressure (that is, the atmospheric pressure in the reactor) may be 0.01 to 1 MPa, 0.05 to 0.8 MPa, or 0.1 to 0.5 MPa. When the reaction pressure is in the above range, the dehydrogenation reaction is likely to proceed, and further excellent reaction efficiency is easily obtained.

In the dehydrogenation process, when supplying the raw material gas into the reactor continuously, a weight hourly space velocity (WHSV), for example 0.1 h ^-1 or more, 0.5h ^-1 or more, ^{20h -1} or less, or 10h ^- It may be ¹ or less. When the WHSV is 0.1 h ⁻¹ or more, the capacity of the reactor is easily suppressed. When the WHSV is 20 h ⁻¹ or less, the olefin conversion rate tends to increase. In addition, the usage-amount of each of source gas and a dehydrogenation catalyst may be suitably adjusted according to reaction conditions or the activity of a dehydrogenation catalyst. WHSV is not limited to the above range.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment.

  In the dehydrogenation step, two types of dehydrogenation catalysts may be used. For example, the first dehydrogenation catalyst may be filled in the front stage (upstream side) of the reactor, and the second dehydrogenation catalyst may be further filled in the rear stage (downstream side) of the reactor. The first dehydrogenation catalyst may be superior to the second dehydrogenation catalyst in activity of generating an olefin by dehydrogenation of alkane. The second dehydrogenation catalyst may be superior to the first dehydrogenation catalyst in activity of generating a conjugated diene by olefin dehydrogenation. By using these two types of dehydrogenation catalysts in combination, the proportion of the conjugated diene in the final product gas can be increased. The first dehydrogenation catalyst may be the dehydrogenation catalyst according to the present embodiment, and the second dehydrogenation catalyst may be the dehydrogenation catalyst according to the present embodiment. Since the dehydrogenation catalyst which concerns on this embodiment is excellent in the activity which produces | generates a conjugated diene by hydrogenation of an olefin especially, it is suitable for a 2nd dehydrogenation catalyst. Neither the first dehydrogenation catalyst nor the second dehydrogenation catalyst should contain chlorine atoms.

  When the dehydrogenation catalyst according to this embodiment is used as the second dehydrogenation catalyst, the first dehydrogenation catalyst is also selected from the group consisting of a support, tin supported on the support, platinum, ruthenium, and iridium. And at least one active metal. When using the dehydrogenation catalyst which concerns on this embodiment as a 2nd dehydrogenation catalyst, the sum total of content of the active metal in a 1st dehydrogenation catalyst is 0 with respect to the mass of the whole 1st dehydrogenation catalyst. It may be 1% by mass or more and 5% by mass or less, or 0.5% by mass or more and 2% by mass or less.

  When the dehydrogenation catalyst according to this embodiment is used as the second dehydrogenation catalyst, the first dehydrogenation catalyst is a chromic acid / alumina catalyst, a nickel calcium phosphate catalyst, an iron chromium catalyst, a chromium alumina magnesia catalyst, a noble metal. It may be at least one selected from the group consisting of a catalyst, a catalyst containing iron and potassium, and a catalyst containing molybdenum.

  You may perform a 1st dehydrogenation process and the following 2nd dehydrogenation process. In the first dehydrogenation step, the first product gas containing olefin is obtained by hydrogenating the alkane in the raw material gas using the first dehydrogenation catalyst charged in the first reactor. Good. In the second dehydrogenation step, the second product containing conjugated diene is obtained by dehydrogenating the olefin in the first product gas using the second dehydrogenation catalyst charged in the second reactor. You may get gas. According to such a production method, a second product gas having a high conjugated diene content can be obtained.

  The dehydrogenation catalyst according to this embodiment may be used for dehydrogenation of oxygen-containing compounds such as alcohols, aldehydes, ketones, and carboxylic acids. A catalyst having the same composition as the dehydrogenation catalyst according to this embodiment may be used for hydrogenation of unsaturated hydrocarbons, which is the reverse reaction of the dehydrogenation reaction.

  EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited to an Example.

Example 1
5.9 g of sodium stannate trihydrate was dissolved in about 120 ml of water to obtain a first solution. As sodium stannate, sodium stannate trihydrate (Na ₂ SnO ₃ .3H ₂ O) manufactured by Showa Kako Co., Ltd. was used. The first solution and 10.0 g of γ-alumina were mixed to prepare a mixture. As γ-alumina, Neo Bead GB-13 manufactured by Mizusawa Chemical Industry was used. Water was removed from the mixture by heating the mixture at about 50 ° C. using an evaporator. Subsequently, the mixture was dried at 130 ° C. overnight, and the mixture was further calcined at 550 ° C. for 3 hours. The dehydrogenation catalyst A-1 of Example 1 was obtained by the above procedure.

  Based on the ICP emission spectroscopic analysis, the content of tin (element) in the dehydrogenation catalyst A-1 was measured. In the same manner, the content of chlorine (element) in the dehydrogenation catalyst A-1 was measured. The contents of tin and chlorine in the dehydrogenation catalyst A-1 are shown in Table 1 below. “<0.01” in Table 1 means that the chlorine content did not reach 0.01% by mass of the detection limit value. By the same analysis method, it was confirmed that the dehydrogenation catalyst A-1 does not contain any of platinum, ruthenium and iridium.

4.00 g of dehydrogenation catalyst A-1 was charged into a flow reactor. The inner diameter of the flow reactor was 10 mmφ. The dehydrogenation catalyst in the reactor was reduced with hydrogen by heating at 550 ° C. for 3 hours in the presence of hydrogen gas. Subsequently, the raw material gas was supplied to the dehydrogenation catalyst in the reactor, and the raw material gas was dehydrogenated. As the source gas, 2-butene, that is, a mixture of trans-2-butene and cis-2-butene was used. The atmospheric pressure in the reactor was maintained at normal pressure. The reaction temperature was maintained at 620 ° C. The source gas contained nitrogen and water (water vapor) in addition to 2-butene. The molar ratio of 2-butene: nitrogen: water in the raw material gas was adjusted to 1.5: 5.3: 3.2. WHSV was adjusted to 0.25 h ⁻¹ .

  The time T (1, 2, 4, 14) shown in Table 2 below is the elapsed time from the start of the dehydrogenation reaction. At each time point 1 hour, 2 hours, 4 hours, and 14 hours after the start of the dehydrogenation reaction, the product gas of the dehydrogenation reaction was collected. The product gas at each time point was analyzed using a gas chromatograph equipped with a flame ionization detector (FID) and a thermal conductivity detector (TCD). The analyzer was an Agilent GC-6850.

The concentration of 2-butene and the concentration of butadiene in the product gas were quantified by an absolute calibration curve method based on the gas chromatograph. Next, based on the quantified 2-butene concentration and butadiene concentration, the conversion of 2-butene, the selectivity of butadiene, and the yield of butadiene were calculated. Table 2 shows the conversion of 2-butene and the yield of butadiene at each time point. The conversion rate of 2-butene is defined by the following formula 1. The selectivity for butadiene is defined by Equation 2 below. The yield of butadiene is defined by Equation 3 below.
R _C (%) = (M ₀ −M ₁ ) / M ₀ × 100 (1)
_RC is the conversion of 2-butene, M ₀ is the concentration (mass%) of 2-butene in the raw material gas, and M ₁ is the concentration (mass%) of 2-butene in the product gas.
R _S (%) = (M _P / M _b ) × 100 (2)
R _S is the selectivity of butadiene, the M _P is the concentration of butadiene in the product gas (mass%). _Mb is the concentration (% by mass) of the carbon compound (excluding 2-butene) in the product gas.
R _Y (%) = R _C × R _S ÷ 100 (3)
_RY is the yield of butadiene.

Furthermore, the deterioration degree of the conversion rate of 2-butene defined by the following formula 4 was calculated. Table 2 shows the degree of deterioration of the conversion rate of 2-butene in the examples.
Dc (% / hour) = (R _C0 -R _CF ) / (T _F -T ₀ ) (4)
Dc is the degree of deterioration of the conversion rate of 2-butene. R _C0 is the conversion of 2-butene at the time when the product gas is first collected (T ₀ hours after the start of the reaction). R _CF is the conversion rate of 2-butene at the time when the product gas is finally collected (time _TF after the start of the reaction). The deterioration degree Dc of the conversion rate of 2-butene is so small that deterioration of the dehydrogenation activity of a dehydrogenation catalyst is suppressed. In Example 1, T ₀ was 1 hour and T _F was 14 hours.

Furthermore, the deterioration degree of the yield of butadiene defined by the following formula 5 was calculated. The degree of deterioration of the butadiene yield in the examples is shown in Table 2 below.
_{D Y (% / hour) =} (R Y0 -R YF) / (T F -T 0) (5)
_DY is the degree of deterioration of the yield of butadiene. R _Y0 is the yield of butadiene at the time when the product gas is first collected (T ₀ hours after the start of the reaction). R _YF is the yield of butadiene at the time when the product gas is finally collected (time _TF after the start of the reaction). As deterioration of the dehydrogenation activity of the dehydrogenation catalyst is suppressed, the deterioration degree D _Y butadiene yield is small.

(Example 2)
Magnesium nitrate hexahydrate (25.1 g) was dissolved in about 150 ml of water to obtain a third aqueous solution. The magnesium nitrate was used manufactured by Wako Pure Chemical Industries, Ltd. of magnesium nitrate hexahydrate _{(Mg (NO 3) 2 ·} 6H 2 O). A first mixture was prepared by mixing 20.0 g of γ-alumina and the third aqueous solution. As γ-alumina, Neo Bead GB-13 manufactured by Mizusawa Chemical Industry Co., Ltd. was used. Water was removed from the first mixture by heating the first mixture at about 50 ° C. using an evaporator. Subsequently, the first mixture was dried at 130 ° C. overnight. The dried mixture was baked at 550 ° C. for 3 hours and then baked at 800 ° C. for 3 hours to obtain a baked product.

  The same magnesium nitrate hexahydrate 25.1 g as above was dissolved in about 150 ml of water to obtain a third aqueous solution again. The fired product and the third aqueous solution were mixed to prepare a second mixture. Water was removed from the second mixture by heating the second mixture at about 50 ° C. using an evaporator. Subsequently, the second mixture was dried at 130 ° C. overnight. The dried second mixture was calcined at 550 ° C. for 3 hours, and then calcined at 800 ° C. for 3 hours. By the above procedure, an alumina-magnesia carrier having a spinel structure was obtained.

  The obtained alumina-magnesia support was analyzed by X-ray diffraction. The X-ray diffraction pattern of the alumina-magnesia support had a plurality of diffraction peaks with diffraction angles 2θ of 36.9 °, 44.8 °, 59.4 ° and 65.3 °. All of these diffraction peaks were confirmed to be derived from a magnesia spinel structure.

  3.7 g of sodium stannate hydrate was dissolved in about 100 ml of water to obtain a first solution. The same sodium stannate as in Example 1 was used. A first mixture and 10.0 g of alumina-magnesia support were mixed to prepare a third mixture. Water was removed from the third mixture by heating the third mixture at about 50 ° C. using an evaporator. Subsequently, the third mixture was dried at 130 ° C. overnight, and further the third mixture was calcined at 550 ° C. for 3 hours. The dehydrogenation catalyst A-2 of Example 2 was obtained by the above procedure.

  Based on the ICP emission spectroscopic analysis, the content of tin (element) in the dehydrogenation catalyst A-2 was measured. In the same manner, the content of chlorine (element) in the dehydrogenation catalyst A-2 was measured. The contents of tin and chlorine in the dehydrogenation catalyst A-2 are shown in Table 1 below. By the same analysis method, it was confirmed that the dehydrogenation catalyst A-2 does not contain any of platinum, ruthenium and iridium.

  The dehydrogenation reaction of Example 2 was performed in the same manner as in Example 1 except that the dehydrogenation catalyst A-2 was used instead of the dehydrogenation catalyst A-1. In the same manner as in Example 1, the product gas of the dehydrogenation reaction in Example 2 was collected and analyzed. Based on the analysis, the conversion of 2-butene and the yield of butadiene at each time point of the dehydrogenation reaction of Example 2 were calculated. In the same manner as in Example 1, the degree of deterioration of the 2-butene conversion rate in Example 2 was calculated. In the same manner as in Example 1, the degree of deterioration of the butadiene yield in Example 2 was calculated. The results of the dehydrogenation reaction of Example 2 are shown in Table 2 below.

(Example 3)
A first solution was obtained by dissolving 5.0 g of tin sulfate in about 120 ml of water. As the tin sulfate, tin sulfate (SnSO ₄ ) manufactured by Kishida Chemical Co., Ltd. was used. The first solution and 10.0 g of silica were mixed to prepare a mixture. As silica, carry act Q6 manufactured by Fuji Silysia Chemical Ltd. was used. Water was removed from the mixture by heating the mixture at about 50 ° C. using an evaporator. Subsequently, the mixture was dried at 130 ° C. overnight, and the mixture was further calcined at 550 ° C. for 3 hours. The dehydrogenation catalyst A-3 of Example 3 was obtained by the above procedure.

  Based on the ICP emission spectroscopic analysis, the content of tin (element) in the dehydrogenation catalyst A-3 was measured. In the same manner, the content of chlorine (element) in the dehydrogenation catalyst A-3 was measured. The contents of tin and chlorine in the dehydrogenation catalyst A-3 are shown in Table 1 below. By the same method, it was confirmed that the dehydrogenation catalyst A-3 does not contain any of platinum, ruthenium and iridium.

  The dehydrogenation reaction of Example 3 was performed in the same manner as in Example 1 except that the dehydrogenation catalyst A-3 was used instead of the dehydrogenation catalyst A-1. In the same manner as in Example 1, the product gas of the dehydrogenation reaction in Example 3 was collected and analyzed. Based on the analysis, the conversion of 2-butene and the yield of butadiene at each time point of the dehydrogenation reaction of Example 3 were calculated. In the same manner as in Example 1, the degree of deterioration of the conversion rate of 2-butene in Example 3 was calculated. In the same manner as in Example 1, the degree of deterioration of the butadiene yield in Example 3 was calculated. The results of Example 3 are shown in Table 2 below.

(Comparative Example 1)
5.9 g of sodium stannate trihydrate was dissolved in about 120 ml of water to obtain a first solution. The same sodium stannate as in Example 1 was used. A mixture was prepared by mixing 10.0 g of γ-alumina and the first solution. As γ-alumina, the same one as in Example 1 was used. Water was removed from the mixture by heating the mixture at about 50 ° C. using an evaporator. Subsequently, the mixture was dried at 130 ° C. overnight. The dried mixture was baked at 550 ° C. for 3 hours to obtain a baked product. The fired product is alumina on which tin is supported.

As a second solution, an aqueous solution of tetraammineplatinum (II) nitrate ([Pt (NH ₃ ) ₄ ] (NO ₃ ) ₂ ) manufactured by Tanaka Kikinzoku Kogyo Co., Ltd. was prepared. After impregnating the fired product with the second solution, the fired product was dried at 130 ° C. overnight. The fired product after drying was further fired at 550 ° C. for 3 hours. By the above procedure, dehydrogenation catalyst B-1 of Comparative Example 1 was obtained. The platinum (element) content in the dehydrogenation catalyst B-1 was adjusted to about 1% by mass.

  Based on the ICP emission spectroscopic analysis, the contents of tin, chlorine and platinum in the dehydrogenation catalyst B-1 were measured. The content of each element in the dehydrogenation catalyst B-1 is shown in Table 1 below.

Using the dehydrogenation catalyst B-1 of Comparative Example 1, the following two dehydrogenation reactions were performed individually. In one dehydrogenation reaction (first dehydrogenation reaction), WHSV was adjusted to 1.00 h ⁻¹ . In the other dehydrogenation reaction (second dehydrogenation reaction), WHSV was adjusted to 0.25 h ⁻¹ .

[First dehydrogenation reaction]
In the first dehydrogenation reaction in which WHSV is 1.00 h ⁻¹ , 1.00 g of dehydrogenation catalyst B-1 was used instead of 4.00 g of dehydrogenation catalyst A-1. That is, the first dehydrogenation reaction of Comparative Example 1 was performed in the same manner as in Example 1 except for the composition of the catalyst and its mass. In the same manner as in Example 1, the product gas of the first dehydrogenation reaction in Comparative Example 1 was collected and analyzed. Based on the analysis, the conversion of 2-butene and the yield of butadiene at each time point of the first dehydrogenation reaction of Comparative Example 1 were calculated. In the same manner as in Example 1, the degree of deterioration of the conversion rate of 2-butene in the first dehydrogenation reaction of Comparative Example 1 was calculated. In the same manner as in Example 1, the degree of deterioration of the butadiene yield in the first dehydrogenation reaction of Comparative Example 1 was calculated. The results of the first dehydrogenation reaction of Comparative Example 1 are shown in Table 2 below.

[Second dehydrogenation reaction]
In the second dehydrogenation reaction in which WHSV was 0.25 h ⁻¹ , dehydrogenation catalyst B-1 was used instead of dehydrogenation catalyst A-1. The second dehydrogenation reaction of Comparative Example 1 was performed in the same manner as in Example 1 except for the composition of the dehydrogenation catalyst. In the same manner as in Example 1, the product gas of the second dehydrogenation reaction in Comparative Example 1 was collected and analyzed. Based on the analysis, the conversion of 2-butene and the yield of butadiene at each time point of the second dehydrogenation reaction of Comparative Example 1 were calculated. In the same manner as in Example 1, the degree of deterioration of the conversion rate of 2-butene in the second dehydrogenation reaction of Comparative Example 1 was calculated. In the same manner as in Example 1, the degree of deterioration of the butadiene yield in the second dehydrogenation reaction of Comparative Example 1 was calculated. The results of the second dehydrogenation reaction of Comparative Example 1 are shown in Table 2 below.

(Comparative Example 2)
In Comparative Example 2, an aqueous solution of iridium nitrate (Ir (NO ₃ ) ₄ ) was used as the second solution instead of the aqueous solution of tetraammineplatinum (II) nitrate. As an aqueous solution of iridium nitrate, an aqueous solution of iridium nitrate manufactured by Furuya Metal Co., Ltd. was used. The content of Ir (element) in the aqueous solution of iridium nitrate was 8.4% by mass. A dehydrogenation catalyst B-2 of Comparative Example 2 was produced in the same manner as Comparative Example 1 except for the composition of the second solution. The content of iridium (element) in the dehydrogenation catalyst B-2 was adjusted to about 1% by mass.

  Based on ICP emission spectroscopic analysis, the contents of tin, chlorine and iridium in the dehydrogenation catalyst B-2 were measured. The content of each element in the dehydrogenation catalyst B-2 is shown in Table 1 below.

  The dehydrogenation reaction of Comparative Example 2 was performed in the same manner as the first dehydrogenation reaction of Comparative Example 1 except that the dehydrogenation catalyst B-2 was used instead of the dehydrogenation catalyst B-1. In the same manner as in Example 1, the product gas of the dehydrogenation reaction of Comparative Example 2 was collected and analyzed. Based on the analysis, the conversion of 2-butene and the yield of butadiene at each time point of the dehydrogenation reaction of Comparative Example 2 were calculated. In the same manner as in Example 1, the degree of deterioration of the 2-butene conversion rate in Comparative Example 2 was calculated. In the same manner as in Example 1, the degree of deterioration of the butadiene yield in Comparative Example 2 was calculated. The results of the dehydrogenation reaction of Comparative Example 2 are shown in Table 2 below.

(Comparative Example 3)
In Comparative Example 3, an aqueous solution of ruthenium nitrate (Ru (NO ₃ ) ₃ ) was used as the second solution instead of the aqueous solution of tetraammineplatinum (II) nitrate. As an aqueous solution of ruthenium nitrate, an aqueous solution of ruthenium nitrate manufactured by Furuya Metal Co., Ltd. was used. The content of ruthenium (element) in the aqueous solution of ruthenium nitrate was 4.5% by mass. A dehydrogenation catalyst B-3 of Comparative Example 3 was produced in the same manner as Comparative Example 1 except for the composition of the second solution. The content of ruthenium (element) in the dehydrogenation catalyst B-3 was adjusted to about 1% by mass.

  Based on the ICP emission spectroscopic analysis, the contents of tin, chlorine and ruthenium in the dehydrogenation catalyst B-3 were measured. The content of each element in the dehydrogenation catalyst B-3 is shown in Table 1 below.

  The dehydrogenation reaction of Comparative Example 3 was performed in the same manner as the first dehydrogenation reaction of Comparative Example 1 except that the dehydrogenation catalyst B-3 was used instead of the dehydrogenation catalyst B-1. In the same manner as in Example 1, the product gas of the dehydrogenation reaction of Comparative Example 3 was collected and analyzed. Based on the analysis, the conversion of 2-butene and the yield of butadiene at each time point of the dehydrogenation reaction of Comparative Example 3 were calculated. In the same manner as in Example 1, the degree of deterioration of the conversion rate of 2-butene in Comparative Example 3 was calculated. In the same manner as in Example 1, the degree of deterioration of the butadiene yield in Comparative Example 3 was calculated. The results of the dehydrogenation reaction of Comparative Example 3 are shown in Table 2 below.

  According to the present invention, for example, butadiene can be produced by dehydrogenation of n-butene while suppressing deterioration of the dehydrogenation catalyst.

Claims (6)

A step of obtaining an unsaturated hydrocarbon by dehydrogenating at least one of alkane and olefin using a dehydrogenation catalyst,
The dehydrogenation catalyst comprises a support and tin supported on the support;
When the active metal is defined as at least one selected from the group consisting of platinum, ruthenium and iridium, the total content of the active metal in the dehydrogenation catalyst is based on the total mass of the dehydrogenation catalyst. 0.0 mass% or more and less than 0.1 mass%,
A method for producing unsaturated hydrocarbons. By using the dehydrogenation catalyst to dehydrogenate the olefin, a conjugated diene is obtained as the unsaturated hydrocarbon.
The method for producing an unsaturated hydrocarbon according to claim 1. The tin content is 5% by mass or more and 25% by mass or less with respect to the mass of the entire dehydrogenation catalyst.
The manufacturing method of the unsaturated hydrocarbon of Claim 1 or 2. The chlorine content is 0.00 mass% or more and 0.01 mass% or less with respect to the mass of the entire dehydrogenation catalyst.
The manufacturing method of the unsaturated hydrocarbon as described in any one of Claims 1-3. A method for producing the dehydrogenation catalyst comprises:
Impregnating a carrier with a first solution in which a tin source is dissolved, and supporting the tin on the carrier;
The tin source is at least one selected from the group consisting of sodium stannate and potassium stannate;
The manufacturing method of the unsaturated hydrocarbon as described in any one of Claims 1-4. The first solution is an aqueous solution;
The method for producing an unsaturated hydrocarbon according to claim 5.