TW201542512A - Process for producing an unsaturated hydrocarbon - Google Patents

Abstract

To provide a process for producing an unsaturated hydrocarbon by dehydrogenating a hydrocarbon with the use of a dehydrogenation catalyst, the process effectively suppressing the volatilization of zinc from the dehydrogenation catalyst and thereby producing an unsaturated hydrocarbon, i.e., an olefin and/or a diene with stability over a long period of time. [Solution Means] A process for producing an unsaturated hydrocarbon comprising a step of allowing a raw material-containing gas (1) containing a hydrocarbon to contact with metal zinc, a zinc compound or both thereof and then to contact with a dehydrogenation catalyst, which comprises zinc as an active component, for dehydrogenation of the hydrocarbon to produce the unsaturated hydrocarbon.

Description

Method for producing unsaturated hydrocarbon

The present invention relates to a process for producing an unsaturated hydrocarbon by performing a dehydrogenation reaction of a hydrocarbon.

Unsaturated hydrocarbons, especially olefins and dienes, are very useful as base materials for various derivatives in the petrochemical industry. Typical examples of the lower olefin and the diene include propylene, 1-butene, 2-butene, isobutylene, and 1,3-butadiene. It is known that these lower olefins and dienes are also produced by dehydrogenating corresponding alkanes and/or olefins, and it is known, for example, to support a catalyst for chromic oxide on an alumina support, such as an alumina carrier. A catalyst in which platinum is supported on a spinel carrier such as zinc aluminate is suitable for the production thereof (Non-Patent Document 1). Further, in Patent Documents 1 to 9, it is disclosed that a catalyst in which platinum and zinc are supported on a zeolite carrier exhibits a high activity for a long period of time as compared with other catalyst systems.

On the other hand, since the metal zinc has a low melting point of about 420 ° C and a high vapor pressure, in the case of a dehydrogenation catalyst containing metallic zinc as an active component, it is a typical high temperature and low pressure. Under the dehydrogenation reaction conditions, the metal zinc continuously volatilizes from the catalyst, and as a result, the catalyst is irreversibly deteriorated.

As a method of suppressing volatilization on the zinc self-catalyst, for example, it is described in the text of Patent Document 7 that it is effective to add a Group IVB element such as zirconium. Further, in Patent Document 10, an aromatic catalyst which is a propane is disclosed as a zeolite supporting zinc. In the method of adding gallium, Patent Document 11 discloses a method in which a zeolite containing zinc is used as an aromatic catalyst for a lower hydrocarbon, and carbon dioxide, steam, thiophene or the like is supplied together with a material gas. Further, Patent Document 12 discloses that the formation of zinc aluminate by the reaction of the zinc component contained in the aromatic catalyst with alumina contributes greatly to the stabilization of zinc.

[Previous Technical Literature] [Patent Literature]

Patent Document 1: US Patent No. 4,962,266

Patent Document 2: U.S. Patent No. 5,126,502

Patent Document 3: U.S. Patent No. 5,208,201

Patent Document 4: US Patent No. 5,324,702

Patent Document 5: US Patent No. 5,453,558

Patent Document 6: U.S. Patent No. 6,197,717

Patent Document 7: U.S. Patent No. 6,555,724

Patent Document 8: International Publication No. 2012/020743

Patent Document 9: Japanese Patent Laid-Open Publication No. 2012-026197

Patent Document 10: U.S. Patent No. 4,490,569

Patent Document 11: U.S. Patent No. 4,849,568

Patent Document 12: Japanese Patent Laid-Open No. Hei 10-52646

[Non-patent literature]

Non-Patent Document 1: Industrial Organic Chemicals, Third Edition, Wiley, page 214

However, the inventors of the present invention applied the zinc volatilization suppressing technique found in the development of such aromatic catalysts to a dehydrogenation catalyst, and as a result, the effects obtained were small, or the activity was greatly reduced. Therefore, it is understood that the above zinc volatilization suppression technique is absolutely difficult to meet the requirements. Therefore, it is expected to establish an effective method for stabilizing zinc which can be applied to a dehydrogenation catalyst.

Accordingly, an object of the present invention is to provide a method for dehydrogenating a hydrocarbon to produce an unsaturated hydrocarbon using a dehydrogenation catalyst, and to stably inhibit the volatilization of zinc from the dehydrogenation catalyst for a long period of time. An unsaturated hydrocarbon, i.e., an olefin or a diene, is produced.

The inventors of the present invention conducted intensive studies to solve the above problems, and found that by contacting the raw material gas with the metal zinc and/or the zinc compound, it is contacted with the catalyst, or by containing the raw material gas containing the zinc vapor. Contact with the catalyst can effectively suppress the volatilization of the zinc self-catalyst, and as a result, the unsaturated hydrocarbons, that is, the olefins and the dienes can be stably produced for a long period of time.

That is, one aspect of the present invention is a method for producing an unsaturated hydrocarbon (hereinafter also referred to as "manufacturing method (1)"), which comprises the steps of: causing a hydrocarbon-containing raw material gas (1) and a metal zinc or zinc compound The two or the like are contacted, and then contacted with a dehydrogenation catalyst containing zinc as one of the active ingredients to carry out a dehydrogenation reaction of the hydrocarbon to produce an unsaturated hydrocarbon.

Further, another aspect of the present invention is a method for producing an unsaturated hydrocarbon (hereinafter also referred to as "manufacturing method (2)"), which comprises the steps of: containing a raw material gas (2) containing hydrocarbons and zinc vapor and containing Zinc is contacted as a dehydrogenation catalyst which is one of the active components, and the hydrocarbon is dehydrogenated to produce an unsaturated hydrocarbon.

The above-mentioned raw material-containing gas (2) can be obtained by making the above-mentioned raw material-containing gas (1) and metallic zinc or zinc Obtained by contacting the compound or both.

Preferably, the reaction temperature of the above dehydrogenation reaction is 300 to 800 ° C, and the reaction pressure is 0.01 to 1 MPa.

The partial pressure of the zinc vapor contained in the raw material-containing gas (2) is equal to or lower than the vapor pressure of zinc at the reaction temperature of the above-described dehydrogenation reaction. As a supply source of zinc vapor, metal zinc or zinc oxide or both are preferable.

The hydrocarbon as a raw material is preferably at least one selected from the group consisting of propane, n-butane and isobutane, or n-butene.

In the above production method (1), the raw material-containing gas (1) preferably further contains water vapor and/or hydrogen.

In the above production method (2), the raw material-containing gas (2) preferably further contains water vapor and/or hydrogen.

Further, a preferred embodiment of the dehydrogenation catalyst is a catalyst in which zeolite is used as a carrier and zinc and a Group VIIIA metal are supported as an active component. The amount of zinc contained in such a catalyst is preferably 0.01 to 15% by weight based on 100% by weight of the total amount of the catalyst, and the amount of the Group VIIIA metal is such a catalyst. The weight of the whole is set to 100% by weight, preferably 0.01 to 5% by weight. Further, as the Group VIIIA metal, platinum is preferred.

As the above zeolite, a porphyrite or a borosilicate is preferable, and a structure having an MFI structure is more preferable. Further preferably, the zeolite carrier is a bismuth salt obtained by removing at least a part of boron atoms from the MFI type borosilicate, and particularly preferably a boron atom residual ratio in the bismuth citrate is a total of boron atoms in the MFI type borosilicate. 80% or less of the amount.

According to the present invention, zinc can be effectively suppressed by a very simple method Volatilization on the dehydrogenation catalyst results in a relatively high activity of the dehydrogenation catalyst for a long period of time, so that it is economically advantageous to produce unsaturated hydrocarbons, i.e., olefins or dienes.

Fig. 1 shows a case where zinc oxide is filled on the upstream side of the gas flow path in the reaction tube with respect to the catalyst layer (Example 1, plotted by ○) and unfilled with zinc oxide (Comparative Example 1, plotted by ●) A plot of the difference in the change in propylene yield over time.

Hereinafter, the details of the present invention will be described.

The method for producing an unsaturated hydrocarbon of the present invention (manufacturing method (1)) comprises the steps of contacting a hydrocarbon-containing raw material gas (1) with a metal zinc or zinc compound or both, and then containing zinc as an active ingredient. A dehydrogenation catalyst is contacted to carry out a dehydrogenation reaction of the hydrocarbon to produce an unsaturated hydrocarbon.

In another aspect of the invention, the manufacturer of the unsaturated hydrocarbon of the invention The method (manufacturing method (2)) includes the steps of: contacting a raw material gas (2) containing hydrocarbons and zinc vapor with a dehydrogenation catalyst containing zinc as one of active ingredients, and performing a dehydrogenation reaction of the hydrocarbon to produce no Saturated hydrocarbons.

In addition, the following description is applicable to both the manufacturing method (1) and the above-mentioned manufacturing method (2) unless otherwise specified.

The reaction temperature in the above dehydrogenation reaction is preferably in the range of 300 to 800 °C, further preferably 400 to 700 ° C, particularly preferably 450 to 650 ° C. When the reaction temperature is at least the above lower limit value, the hydrocarbon as a raw material is converted into an unsaturated hydrocarbon at a relatively high equilibrium conversion ratio, so that an unsaturated hydrocarbon can be produced in a single yield at a higher yield. In addition, when the reaction temperature is at most the above upper limit value, the caulking speed does not become large, and deterioration of the activity of the catalyst can be suppressed.

The reaction pressure is preferably in the range of 0.01 to 1 MPa, and more preferably 0.01~0.5MPa. The lower the reaction pressure, the higher the equilibrium conversion rate of the hydrocarbon as a raw material, and the higher the yield of the unsaturated hydrocarbon in one pass.

Since the production method of the present invention is carried out in a gas phase, it is preferred to carry out the reaction in a continuous reaction apparatus. At this time, it is more convenient to use the amount of the catalyst in terms of the weight space velocity WHSV (Weight Hourly Space Velocity, the supply weight of the hydrocarbon per unit weight of the catalyst and the unit time). In the present invention, the range of the WHSV is not particularly limited, but is preferably 0.01 to 50 h ^-1 , more preferably 0.1 to 20 h ^-1 .

The present invention is characterized in that in the above production method (2), zinc is contained The raw material gas containing the vapor is in contact with a catalyst containing zinc as one of the active ingredients. By causing the zinc vapor to contact the catalyst, the volatilization of the zinc from the catalyst is suppressed, and as a result, the catalyst can exhibit stable performance for a long period of time. The partial pressure of the zinc vapor contained in the raw material gas in contact with the catalyst is lower than the vapor pressure of the zinc at the reaction temperature, and the concentration (volume basis) of the zinc vapor contained in the raw material gas is a concentration exceeding 0%. It is preferably 0.01% or more, and more preferably 0.05% or more.

Examples of the supply source of the zinc vapor include metal zinc, zinc oxide, and the like. Zinc nitrate, zinc chloride, zinc acetate, zinc aluminate or the like is preferably zinc metal or zinc oxide or both.

The source of the zinc vapor is heated to generate a specific partial pressure of zinc vapor, and the temperature thereof is preferably 300 ° C or more and the reaction temperature or lower, more preferably 400 ° C or higher and the reaction temperature or lower, and particularly preferably 450 ° C or higher. And the reaction temperature is below.

The method of supplying the zinc vapor to the raw material-containing gas is not particularly limited, and for example, the metal may be contained in another chamber other than the reactor (that is, the vessel for performing the dehydrogenation reaction of the hydrocarbon). The zinc and/or the zinc compound is heated to a specific temperature to pass a mixed gas of a gas containing a hydrocarbon as a raw material and an inert gas of any use, thereby maximizing a gas mixture of a gas containing a hydrocarbon as a raw material and an inert gas. The ground contains zinc vapor of vapor pressure. Further, a catalyst layer containing the catalyst may be formed in the reaction tube, and a layer of zinc oxide or zinc aluminate may be provided on the upstream side of the gas flow path in the reaction tube with respect to the catalyst layer, by reducing property. The layer is heated in the presence of a gas (for example, hydrogen) to generate zinc vapor from the layer, and a mixed gas of a gas containing a hydrocarbon as a raw material, an inert gas of any use, and any unreacted reducing gas is about to The mixed gas is maximally contained with a vapor pressure of zinc vapor before being contacted with the catalyst layer.

The supply of the zinc vapor may be carried out continuously or intermittently, and in the case of intermittent supply, it is necessary to provide another chamber than the reactor.

In the present invention, a hydrocarbon converted to an unsaturated hydrocarbon by a dehydrogenation reaction is supplied to the reactor. From the viewpoint of industrial usefulness, the unsaturated hydrocarbon produced by the present invention is preferably an olefin (an unsaturated hydrocarbon having one double bond in one molecule) and a diene (two in one molecule) Double bond unsaturated hydrocarbon). That is, the method for producing an unsaturated hydrocarbon of the present invention is preferably a method for producing an olefin or a diene.

The compound which is particularly preferred as a raw material, that is, a hydrocarbon, is propane, n-butane, isobutane, 1-butene, 2-butene, and the like, and a compound which is particularly preferable as the above unsaturated hydrocarbon is propylene or 1-butene. , 2-butene, isobutylene, 1,3-butadiene, and mixtures thereof. A mixture of 1-butene and 2-butene is commonly referred to as n-butene.

The gas of the hydrocarbon as a raw material may be supplied to the reactor together with other gases which do not inhibit the effects of the present invention. Examples of the other gas include steam, nitrogen, carbon dioxide gas, hydrogen gas, methane gas and the like. Among them, water vapor is preferred in terms of extending the life of the dehydrogenation catalyst. Also, as other gas The body may also supply a residual portion of hydrogen gas used to generate zinc vapor from zinc oxide. There is no particular limitation on the mixing method and mixing ratio of the hydrocarbon gas and the above other gases.

The reaction form used in the present invention is not particularly limited, and a known method can be employed, and examples thereof include a fixed bed, a moving bed, and a fluid bed. In terms of the ease of design of the process, it is particularly preferred to be in the form of a fixed bed.

In the present invention, a dehydrogenation catalyst containing zinc as one of the active ingredients is used, and a catalyst containing zeolite as a carrier and supporting zinc and a Group VIIIA metal as an active ingredient is preferably used.

The zinc and the Group VIIIA metal can be supported on the zeolite, for example, by using a metal compound such as a corresponding metal nitrate, metal chloride or metal complex. The support to the zeolite can be carried out by a known method such as an ion exchange method or an impregnation method, and the supported sequence is also not particularly limited.

Examples of the zinc compound include zinc nitrate, zinc chloride, and zinc acetate. Examples of the Group VIIIA metal compound include chloroplatinic acid, tetraammineplatinum chloride, tetraammineplatinum hydroxide, and tetraammineplatinum nitrate.

The amount of zinc contained in the dehydrogenation catalyst is preferably 0.01 to 15% by weight, and more preferably 0.05%, based on the ratio of the weight of the zinc metal atom to the total weight of the catalyst (100% by weight). 5 wt%, particularly preferably 0.1 to 3 wt%.

The amount of the Group VIIIA metal contained in the above dehydrogenation catalyst is preferably 0.01 to 5% by weight based on the weight of the Group VIIIA metal atom relative to the total weight of the catalyst (100% by weight). It is preferably 0.05 to 3% by weight, particularly preferably 0.1 to 1.5% by weight.

The ratio of zinc to the Group VIIIA metal is usually 0.5 or more, preferably 0.5 to 50, in terms of molar ratio (mol of Zn / mole of metal of Group VIIIA). More preferably, it is 1 to 30, and further preferably 1 to 20.

The above-mentioned Group VIIIA metal is the old international purification and application According to the IUPAC (International Union of Pure and Applide Chemistry) method, if it is based on the IUPAC method, it is a metal of Groups 8-10. Examples of the metal of Group VIIIA include platinum, palladium, rhodium, ruthenium, osmium, nickel, and the like. Among these, from the viewpoint of catalyst activity, platinum is preferred.

In one example of the method for producing the above dehydrogenation catalyst, the above zinc compound is used And optionally, the Group VIIIA metal compound is supported on the zeolite, and then dried and calcined. The drying conditions are not particularly limited, and drying is usually carried out at 80 to 150 ° C for a specific period of time. The calcination conditions are also not particularly limited, and the calcination is usually carried out at 400 to 600 ° C for a specific period of time. The environment at the time of baking is also not particularly limited, and drying and baking are usually carried out under air circulation.

The above-mentioned zeolite is used as a total of crystalline porous aluminosilicates. The names used and referred to are classified according to the structure coding according to the topology. Information on construction, composition, and crystallographic data is known for each structural code (e.g., Atlas of Zeolite Structure Types, 4th Ed., Elsevier 1996, and Collection of Simulated XRD Powder Patterns for Zeolites, Elsevier 1996). Further, as a compound other than the aluminosilicate having the same crystal structure, an enamel containing no aluminum or a metal silicate containing iron, gallium or titanium instead of aluminum is also contained in the zeolite (for example, the science of zeolite) And engineering, Kodansha Scientific).

In the present invention, it is preferred to replace the enamel-free rock or contain boron. Aluminium metal ruthenate, borosilicate, is used as a catalyst carrier.

The aluminum content in the enamel or borosilicate used in the present invention is not particularly limited, and the cerium oxide/alumina molar ratio (the molar number of SiO ₂ / Al ₂ O _{3 in} the zeolite) The molar number is preferably 100 or more, more preferably 500 or more, particularly preferably 1,000 or more, and most preferably 2,000 or more. When the cerium oxide/alumina molar ratio is 100 or more, side reactions such as oligomerization at the acid sites due to aluminum are suppressed. If the cerium oxide/alumina molar ratio is 2,000 or more, such side reaction can be further effectively suppressed.

The boron content in the borosilicate is not particularly limited, and is preferably 100~. 30000ppm, more preferably 500~10000ppm, especially preferably 1000~80000ppm.

Content of alkali metal and alkaline earth metal in enamel or borosilicate It is not particularly limited, and it is preferred that the metals are substantially absent. The term "substantially non-existent" means that the content of alkali metals and alkaline earth metals in the chert or borosilicate is 300 ppm or less.

Further, it is preferred that the enamel rock and the borax silicate have MFI structure.

A borosilicate having an MFI structure (hereinafter also referred to as "MFI type boron borate") may be directly used as a carrier, but it is preferred to remove at least a part of boron atoms from the above MFI type borosilicate. The obtained decanoate was used as a carrier.

After removing at least a portion of the boron atoms from the above MFI type borosilicate The residual ratio of boron atoms in the bismuth citrate is preferably 80% or less, more preferably 50% or less, particularly preferably 30% or less, and most preferably 20% or less of the total amount of boron atoms in the borosilicate.

The residual ratio of boron atoms is in the boron borate before removing the boron atom. The content of the boron atom is calculated by comparison with the content of the boron atom in the citrate after removal of the boron atom. The method of removing at least a part of the boron atom from the above borosilicate is not limited, and a known method such as a treatment with an aqueous solution of a mineral acid or an organic acid can be employed.

The catalyst filled in the reactor may be in the form of a powder or a molded body. The molding method is not limited, and a known method such as extrusion molding, tablet molding, or coating molding may be employed.

It can also be used after the catalyst is filled in the reactor and before the reaction starts. In the pretreatment for activating the catalyst, in the pretreatment, the above catalyst is usually brought into contact with a reducing gas such as hydrogen or carbon monoxide. These reducing gases may be used without being diluted, or may be appropriately diluted with the inert gas described above.

After a certain period of time after the start of the reaction, it was confirmed that the activity of the catalyst was lowered. In the case of low, the reaction can also be stopped, and the catalyst can be reactivated by a method called regeneration treatment. The method is not particularly limited, and a method is generally employed in which a heavy substance called a coke hydrocarbon attached to a surface of a catalyst is burned and removed by bringing a gas containing oxygen into contact with a catalyst at a specific temperature.

[Examples]

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

(catalyst preparation 1)

10 g of MFI-type borosilicate containing 3,200 ppm of boron atoms was stirred in 200 ml of a 1N aqueous solution of nitric acid at 80 ° C for 2 hours, and then filtered to separate into a cake and a filtrate. Further, the filter cake separated by filtration was stirred at 200 ° C for 2 hours in 200 ml of a 1N aqueous solution of nitric acid, and then filtered to separate into a cake and a filtrate. The above operation was repeated twice, and then separated by filtration with distilled water. The filter cake is washed until the cleaning solution used is neutral. The washed filter cake was dried in a static electric furnace maintained in air at 120 ° C for 3 hours, and then calcined at 500 ° C for 4 hours to obtain at least a part of the boron atom removed from the MFI type borosilicate. Citrate. Obtained The amount of boron atoms in the citrate was 260 ppm, and the residual ratio of boron atoms at this time was 8%.

(catalyst preparation 2)

To 6 g of the phthalate obtained by the catalyst preparation 1, 0.66 g of an aqueous solution containing 0.058 g of zinc nitrate hexahydrate was added, and zinc ions were impregnated by an incipient-wetness method. The ceric acid salt impregnated with zinc ions was dried in a static electric furnace maintained at 120 ° C for 3 hours, and then calcined at 500 ° C for 4 hours to prepare a zinc silicate supported thereon.

(catalyst preparation 3)

1.5 g of zinc ruthenium hydride supported by the catalyst preparation 2 was added to an aqueous solution containing 0.3127 g of chloroplatinic acid hexahydrate, and the platinum ion was impregnated by the incipient wetness method. The ceric acid salt impregnated with platinum ions was dried in a static electric furnace which was circulated in air and kept at 120 ° C for 3 hours, and then calcined at 500 ° C for 4 hours to obtain a citrate contact carrying platinum and zinc. Medium powder. The ruthenium catalyst had a platinum loading of 0.32% by weight and a zinc loading of 0.64% by weight.

[Example 1]

The SUS tube in which the inner tube of the alumina having an inner diameter of 6 mm is mounted is filled with 0.2 g of a platinum and zinc citrate catalyst obtained by the catalyst preparation 3, and then, the quartz cotton is touched. The upstream side of the medium was filled with 0.1 g of zinc oxide (manufactured by Sigma-Aldrich), and before and after the filling, alumina balls were filled to fix the catalyst and zinc oxide, thereby producing a reaction tube. At 600 ° C and atmospheric pressure, the reaction tube was circulated for 2 hours and contained a mixed gas of 20 sccm of hydrogen and 0.064 g/min of water vapor. After pretreatment of the catalyst, hydrogen was supplied 2.1. The dehydrogenation reaction of propane was started with sccm, propane 13.55 sccm, and water vapor of 0.022 g/min. Further, the reaction temperature was raised to 650 ° C at the same time as the start of the reaction.

The catalyst exhibits a stable activity for a long period of time and exhibits a 60% propylene yield for about 120 hours.

[Comparative Example 1]

A reaction tube was produced in the same manner as in Example 1 except that zinc oxide was not filled, and the dehydrogenation reaction of propane was started under the same pretreatment conditions and reaction conditions as in Example 1. The catalyst exhibited a 60% propylene yield for about 60 hours.

[Comparative Example 2]

A reaction tube was produced in the same manner as in Example 1 except that the citrate catalyst was not filled. In the same manner as in Example 1, the reaction tube was passed through a reaction tube at 600 ° C for 2 hours, and contained hydrogen gas of 20 sccm and water vapor of 0.064. After a mixed gas of g/min, hydrogen gas was supplied at 2.1 cc, propane at 13.55 sccm, and water vapor at 0.022 g/min. Zinc oxide does not exhibit catalyst activity in the dehydrogenation of propane at all.

From the above results, it is understood that zinc oxide which is filled upstream of the catalyst has no catalytic activity per se, but on the other hand, the catalyst exhibits high activity for a long period of time due to the presence of zinc oxide.

[Reference example]

A reaction tube was produced in the same manner as in Comparative Example 2 except that a SUS tube to which an alumina intercalation tube was attached was used instead of a SUS tube to which an alumina interposer was attached, and the alumina ball was not filled. In the same manner as in Comparative Example 2, the reaction tube was passed through a reaction tube at 600 ° C for 2 hours, and a mixture of hydrogen gas of 20 sccm and water vapor of 0.064 g/min was used. After the gas, hydrogen gas (2.1 sccm, propane 13.55 sccm, and water vapor of 0.022 g/min) were supplied at 650 °C. In the same manner as in Comparative Example 2, zinc oxide did not exhibit catalyst activity in the dehydrogenation reaction of propane at all, but a silvery and band-shaped film was formed in the lower portion of the quartz tube after the reaction. The solution obtained by dissolving the film with dilute nitric acid was analyzed by inductively coupled plasma (ICP), and it was confirmed that the silvery and strip-shaped film was zinc.

From the above results, it is known that at least a portion of the zinc oxide is in the pretreatment and In the reaction, it is reduced to become metallic zinc, and further, zinc vapor is generated from the place to move in the gas phase. Further, it is also known that the partial pressure of zinc vapor at this time is equal to or lower than the vapor pressure of zinc at 650 ° C as the reaction temperature.

Claims (19)

A method for producing an unsaturated hydrocarbon, comprising the steps of contacting a hydrocarbon-containing raw material gas (1) with a metal zinc or zinc compound or both, and then contacting a dehydrogenation catalyst containing zinc as one of active ingredients The dehydrogenation reaction of the hydrocarbon is carried out to produce an unsaturated hydrocarbon. The method for producing an unsaturated hydrocarbon according to claim 1, wherein the raw material-containing gas (1) further contains water vapor. The method for producing an unsaturated hydrocarbon according to claim 1 or 2, wherein the raw material-containing gas (1) further contains hydrogen. The method for producing an unsaturated hydrocarbon according to claim 1, wherein the method comprises the steps of: contacting a hydrocarbon-containing raw material gas (1) with a metal zinc or zinc compound or both to obtain a hydrocarbon-containing and zinc vapor. The raw material gas (2) is contained, and the raw material-containing gas (2) is brought into contact with a dehydrogenation catalyst containing zinc as one of the active components, and the hydrocarbon is dehydrogenated to produce an unsaturated hydrocarbon. The method for producing an unsaturated hydrocarbon according to the fourth aspect of the invention, wherein the partial pressure of the zinc vapor contained in the raw material-containing gas (2) is equal to or less than the vapor pressure of zinc at the reaction temperature of the dehydrogenation reaction. The method for producing an unsaturated hydrocarbon according to claim 4 or 5, wherein the raw material-containing gas (2) further contains water vapor. The method for producing an unsaturated hydrocarbon according to any one of claims 4 to 6, wherein the raw material-containing gas (2) further contains hydrogen. The method for producing an unsaturated hydrocarbon according to any one of claims 1 to 7, wherein the reaction temperature in the dehydrogenation reaction is 300 to 800 ° C, and the reaction pressure is in the range of 0.01 to 1 MPa. The method for producing an unsaturated hydrocarbon according to any one of claims 1 to 8, wherein the zinc compound is zinc oxide. The method for producing an unsaturated hydrocarbon according to any one of claims 1 to 9, wherein the hydrocarbon is at least one selected from the group consisting of propane, n-butane and isobutane. The method for producing an unsaturated hydrocarbon according to any one of claims 1 to 9, wherein the hydrocarbon is n-butene. The method for producing an unsaturated hydrocarbon according to any one of claims 1 to 11, wherein the dehydrogenation catalyst is a catalyst containing zeolite as a carrier and supporting zinc and a Group VIIIA metal as an active component. The method for producing an unsaturated hydrocarbon according to claim 12, wherein the amount of zinc contained in the dehydrogenation catalyst is 0.01 to 15% by weight when the total weight of the catalyst is 100% by weight. . The method for producing an unsaturated hydrocarbon according to claim 12 or 13, wherein the amount of the Group VIIIA metal contained in the dehydrogenation catalyst is 0.01 when the weight of the entire catalyst is 100% by weight. ~5 wt%. The method for producing an unsaturated hydrocarbon according to any one of claims 12 to 14, wherein the Group VIIIA metal is platinum. The method for producing an unsaturated hydrocarbon according to any one of claims 12 to 15, wherein the zeolite is a sorghum rock or a borosilicate. The method for producing an unsaturated hydrocarbon according to claim 16, wherein the porphyrite or/and the borosilicate has an MFI structure. The method for producing an unsaturated hydrocarbon according to any one of claims 12 to 15, wherein the zeolite is a cerate obtained by removing at least a part of a boron atom from an MFI-type borosilicate. The method for producing an unsaturated hydrocarbon according to claim 18, wherein the residual boron atom in the bismuth citrate is 80% or less of the total amount of boron atoms in the MFI-type borosilicate.