JP2019189585A - Production method of unsaturated hydrocarbon - Google Patents

Abstract

To provide a production method of unsaturated hydrocarbons capable of efficiently converting hydrocarbons by a dehydrogenation reaction with less catalyst degradation, as a novel production method of unsaturated hydrocarbons.SOLUTION: A production method of unsaturated hydrocarbons includes a step of dehydrogenating at least a part of hydrocarbons by flowing a raw material gas containing hydrocarbons having 4 to 9 carbons to a reactor having a catalyst layer in which a dehydrogenation catalyst is filled, in which the dehydrogenation catalyst has a carrier containing aluminum and a carrier metal carried by the carrier, the carrier metal contains tin and platinum, and at an inlet of the catalyst layer, the pressure is 101 kPa or larger and a partial pressure of the hydrocarbon is 17 kPa or lower.SELECTED DRAWING: None

Description

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

  Unsaturated hydrocarbons are required in large quantities in various fields, for example as starting materials for industrial products. For example, unsaturated hydrocarbons are used for manufacturing detergents, high-octane gasoline, chemicals, etc., and also for manufacturing plastics. In particular, butene is widely used as a starting material for methyl ethyl ketone, alkylate gasoline, etc., and as its production method, for example, a method of directly dehydrogenating n-butane using a heterogeneous dehydrogenation catalyst is known. (For example, Patent Documents 1 to 4).

JP 2014-205135 A Japanese Patent Laying-Open No. 2015-027669 US Patent Application Publication No. 2014/0309470 US Pat. No. 6,433,241

  With the increase in demand for unsaturated hydrocarbons, development of various methods for producing unsaturated hydrocarbons having different characteristics such as required characteristics, operating costs, reaction efficiency, etc. of production equipment is required.

  An object of the present invention is to provide a method for producing an unsaturated hydrocarbon, which is a novel method for producing an unsaturated hydrocarbon, which has little catalyst deterioration and can efficiently convert hydrocarbons by a dehydrogenation reaction.

  The present inventors have found that a high dehydrogenation activity is maintained for a long time under a specific dehydrogenation catalyst and a specific reaction condition, and have completed the present invention. In general, since the dehydrogenation reaction is a reaction in which the number of molecules increases, the reaction proceeds more easily as the reaction pressure and the hydrocarbon partial pressure are lower. However, when using a specific dehydrogenation catalyst, the inventors set the reaction pressure and the partial pressure of hydrocarbons to a predetermined value or more to suppress catalyst deterioration, and as a result, efficiently perform the dehydrogenation reaction. I found out that it can be advanced.

  In one aspect of the present invention, a raw material gas containing a hydrocarbon having 4 to 9 carbon atoms is passed through a reactor having a catalyst layer filled with a dehydrogenation catalyst to dehydrogenate at least a part of the hydrocarbon. The present invention relates to a method for producing an unsaturated hydrocarbon, comprising a step. In this production method, the dehydrogenation catalyst has a carrier containing aluminum and a supported metal supported on the carrier, and the supported metal contains tin and platinum. The pressure at the inlet of the catalyst layer is 101 kPa or more, and the partial pressure of the hydrocarbon is 17 kPa or more.

  In one embodiment, the pressure at the inlet of the catalyst layer may be 130 kPa or higher, and the partial pressure of the hydrocarbon at the inlet of the catalyst layer may be 30 kPa or higher. In this case, catalyst deterioration is more significantly suppressed.

  In one embodiment, the atomic ratio (Sn / Pt) of tin and platinum in the dehydrogenation catalyst may be 3.0 or more and 6.0 or less, and the platinum content in the dehydrogenation catalyst is the dehydrogenation catalyst. It may be 0.6 mass% or more and 3.0 mass% or less on the basis of the total amount. In this case, the above-described effect is more remarkably exhibited.

  In one embodiment, the dehydrogenation catalyst may be a catalyst in which tin and platinum are supported on the support using a metal source containing no chlorine atom.

  In one embodiment, the temperature at the inlet of the catalyst layer may be 500 ° C. or higher.

  According to the present invention, as a novel method for producing an unsaturated hydrocarbon, there is provided a method for producing an unsaturated hydrocarbon in which catalyst deterioration is small and the hydrocarbon can be efficiently converted by a dehydrogenation reaction.

  Hereinafter, a preferred embodiment of the present invention will be described.

  In the method for producing an unsaturated hydrocarbon according to the present invention, a raw material gas containing a hydrocarbon having 4 to 9 carbon atoms is circulated through a reactor having a catalyst layer filled with a dehydrogenation catalyst, so that at least one of the hydrocarbons. And dehydrogenating a portion to obtain an unsaturated hydrocarbon.

  In this embodiment, the dehydrogenation catalyst has a support containing aluminum (Al) and a supported metal supported on the support. The supported metal contains tin (Sn) and platinum (Pt).

  In this embodiment, the pressure at the inlet of the catalyst layer (hereinafter also referred to as reaction pressure) is 101 kPa or more, and the partial pressure of hydrocarbon at the inlet of the catalyst layer (hereinafter also referred to as raw material partial pressure). 17 kPa or more.

  According to the production method according to the present embodiment, the catalyst is less deteriorated and the hydrocarbon can be efficiently converted by the dehydrogenation reaction. In general, since the dehydrogenation reaction is a reaction in which the number of molecules increases, the reaction proceeds more easily as the reaction pressure and the hydrocarbon partial pressure are lower. However, when using a specific dehydrogenation catalyst, the present inventors set the reaction pressure and the partial pressure of hydrocarbons to a predetermined value or more to suppress catalyst deterioration, and as a result, efficiently perform the dehydrogenation reaction. I found out that it can be advanced.

  The dehydrogenation catalyst used in the present embodiment is a solid catalyst that catalyzes a hydrocarbon dehydrogenation reaction, and is a catalyst in which a supported metal including Sn and Pt is supported on a support including Al.

The support is preferably an inorganic oxide support containing at least Al. The support may be, for example, a support containing alumina (Al ₂ O ₃ ) or a support containing a composite oxide of Al and another metal. More specifically, for example, the metal oxide support includes alumina, a composite oxide of Al and Mg, a composite oxide of Al and Sn, a composite oxide of Al and Pb, Al and Zn, Se, and Fe. It may be a carrier containing a metal oxide such as a composite oxide with In or the like. The content of Al in the support may be 25% by mass or more based on the total mass of the support, and is preferably 50% by mass or more. Examples of the inorganic oxide carrier containing Al include a carrier containing an inorganic oxide such as alumina, alumina magnesia, silica alumina, zirconia alumina, and spinel structure (magnesium spinel).

  The method for preparing the carrier is not particularly limited, and examples thereof include a sol-gel method, a coprecipitation method, and a hydrothermal synthesis method.

The specific surface area of the carrier may be, for example, 30 m ² / g or more, and preferably 50 m ² / g or more. Thereby, there exists a tendency for the conversion rate of a hydrocarbon to improve further. The specific surface area of the carrier may be, for example, 1000 m ² / g or less, and preferably 500 m ² / g or less. Thereby, it can be set as the support | carrier which has sufficient intensity | strength which can be utilized industrially suitably.

  In the dehydrogenation catalyst, each of the supported metals including tin and platinum may exist as a single oxide, or may exist as a composite oxide with other metals, as a metal salt or a metal simple substance. May be present.

  The dehydrogenation catalyst may be one in which a supported metal is supported on a carrier using a metal source (a compound containing a supported metal). Examples of the metal source include a supported metal precursor described below.

  Examples of the platinum source include tetraammineplatinum (II) acid, tetraammineplatinum (II) acid salt (eg, nitrate), tetraammineplatinum (II) acid hydroxide solution, dinitrodiammine platinum (II) nitric acid solution, hexahydroxo Examples thereof include a platinum (IV) acid nitric acid solution and a hexahydroxoplatinum (IV) acid ethanolamine solution. The platinum source is preferably a compound having platinum (platinum) and not having a chlorine atom.

  The supported amount of platinum (Pt) in the dehydrogenation catalyst may be, for example, 0.6% by mass or more, and preferably 0.9% by mass or more, based on the total amount of the dehydrogenation catalyst. The amount of Pt supported may be, for example, 5.0% by mass or less, preferably 3.0% by mass or less, based on the total amount of the dehydrogenation catalyst. With such a loading amount, the Pt particles formed on the catalyst have a suitable size due to the dehydrogenation reaction, and the platinum surface area per unit platinum weight increases, so a more efficient reaction system can be realized.

  Examples of the tin source include sodium stannate and potassium stannate. The tin source is preferably a compound having tin (Sn) and not having a chlorine atom.

  The atomic ratio (Sn / Pt) of tin (Sn) and platinum (Pt) in the dehydrogenation catalyst may be, for example, 1.0 or more, preferably 3.0 or more, for example, 15.0 or less. It is preferably 6.0 or less. When the atomic ratio of Sn and Pt is in the above range, not only the conversion rate of hydrocarbons is further improved, but also catalyst deterioration is more significantly suppressed, and high activity tends to be maintained for a longer time. .

  The dehydrogenation catalyst may further contain a metal element other than the Group 14 metal element and platinum. Examples of other metal elements include Li, Na, K, Mg, Ca, Zn, Fe, In, Se, Sb, Ni, and Ga.

  The supporting method of the supporting metal is not particularly limited, and examples thereof include an impregnation method, a deposition method, a coprecipitation method, a kneading method, an ion exchange method, and a pore filling method.

  One aspect of the loading method is shown below. First, a carrier is added to a solution containing a precursor of a supported metal (metal source), and the carrier containing the solution is kneaded. Thereafter, the solvent is removed by drying, and the obtained solid is fired, whereby the supported metal can be supported on the support.

  In the above supporting method, the supporting metal precursor may be, for example, a metal salt or a complex. The metal salt of the supported metal may be, for example, an inorganic salt, an organic acid salt, or a hydrate thereof. Inorganic salts may be, for example, sulfates, nitrates, chlorides, phosphates, carbonates and the like. The organic acid salt may be, for example, acetate, oxalate and the like. The supported metal complex may be, for example, an alkoxide complex or an ammine complex.

  The precursor of the supported metal is preferably a metal source containing no chlorine atom. By using a metal source that does not contain chlorine atoms as a precursor, corrosion of the apparatus during catalyst preparation can be prevented.

  Firing can be performed, for example, in an air atmosphere or an oxygen atmosphere. Firing may be performed in one stage, or may be performed in two or more stages. The firing temperature may be any temperature as long as the precursor of the supported metal can be decomposed, and may be, for example, 200 to 1000 ° C or 400 to 800 ° C. In addition, when performing multi-stage baking, at least one step should just be the said baking temperature. The firing temperature at the other stage may be in the same range as described above, for example, and may be 100 to 200 ° C.

  The dehydrogenation catalyst may further contain a molding aid from the viewpoint of improving moldability. The molding aid may be, for example, a thickener, a surfactant, a water retention material, a plasticizer, a binder material, or the like.

  The shape of the dehydrogenation catalyst is not particularly limited, and may be, for example, a pellet shape, a granule shape, a honeycomb shape, a sponge shape, or the like.

  A dehydrogenation catalyst that has been subjected to a reduction treatment as a pretreatment may be used. The reduction treatment can be performed, for example, by holding the dehydrogenation catalyst at 40 to 600 ° C. in a reducing gas atmosphere. The holding time may be, for example, 0.05 to 24 hours. The reducing gas may contain hydrogen, carbon monoxide, etc., for example. By using the dehydrogenation catalyst subjected to the reduction treatment, the initial induction period of the dehydrogenation reaction can be shortened. The initial induction period means a state in which the supported metal in the dehydrogenation catalyst is reduced and is in an active state, and the activity of the catalyst is low.

  Next, the dehydrogenation process in this embodiment will be described in detail.

  The dehydrogenation step is a step of obtaining unsaturated hydrocarbons by contacting hydrocarbons having 4 to 9 carbon atoms with a dehydrogenation catalyst and performing hydrocarbon dehydrogenation. In the present embodiment, a raw material gas containing a hydrocarbon having 4 to 9 carbon atoms is passed through a reactor having a catalyst layer filled with a dehydrogenation catalyst to convert at least a part of the hydrocarbon into an unsaturated hydrocarbon. To do.

  The raw material hydrocarbon is not particularly limited as long as it is a hydrocarbon having a portion that can be dehydrogenated in the molecule. The raw material hydrocarbon may be a saturated hydrocarbon or an unsaturated hydrocarbon. That is, the production method according to the present embodiment may be a method for obtaining an unsaturated hydrocarbon that is a dehydrogenated product of the saturated hydrocarbon from the saturated hydrocarbon, and from the first unsaturated hydrocarbon, the first The method of obtaining the 2nd unsaturated hydrocarbon which is a dehydrogenation thing of this unsaturated hydrocarbon may be sufficient.

  Among the hydrocarbons of the raw material, the saturated hydrocarbon may be, for example, a chain (straight or branched), or may be cyclic. Examples of the saturated hydrocarbon include butane, pentane, hexane, cyclohexane, heptane, methylcyclohexane, octane, octahydroindene and the like. These may be any isomer or a mixture of a plurality of isomers.

  Among the hydrocarbons of the raw material, the unsaturated hydrocarbon may be, for example, a chain (straight or branched), or may be cyclic. Examples of the unsaturated hydrocarbon include butene, pentene, hexene, cyclohexene, heptene, octene, nonene, tetrahydroindene, hexahydroindene, indane and the like. These may be any isomer or a mixture of a plurality of isomers.

  The source gas may contain one kind of hydrocarbon, or may contain two or more kinds.

  The source gas may further contain an inert gas such as nitrogen or argon in addition to the hydrocarbon. The source gas may further contain steam. By coexisting steam, the catalyst activity tends to be more significantly suppressed.

  When the raw material gas contains steam, the steam content is preferably 0.1 times mole or more, more preferably 1.0 times mole or more with respect to the hydrocarbon. Further, the steam content may be, for example, 10 times mol or less, preferably 4 times mol or less.

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

  In the dehydrogenation reaction, the reaction temperature, that is, the temperature at the inlet of the catalyst layer is preferably 500 ° C. or higher. Thereby, reaction activity improves and it can convert a hydrocarbon more efficiently. The upper limit of the reaction temperature is not particularly limited, but it is preferably 800 ° C. or lower, more preferably 700 ° C. or lower, from the viewpoint that catalyst deterioration is more significantly suppressed and high activity can be maintained over a longer period.

  In the dehydrogenation reaction, the reaction pressure, that is, the pressure at the inlet of the catalyst layer is 101 kPa or more, preferably 130 kPa or more. Thereby, catalyst deterioration is suppressed notably and high activity is maintained over a long period of time. The upper limit of the reaction pressure is not particularly limited, but is preferably 1000 kPa or less, more preferably 500 kPa or less, and even more preferably 300 kPa or less, from the viewpoint that the above-described effects can be obtained more remarkably.

  In the dehydrogenation reaction, the raw material partial pressure, that is, the hydrocarbon partial pressure at the inlet of the catalyst layer is 17 kPa or more, preferably 30 kPa or more. Thereby, catalyst deterioration is suppressed more significantly and high activity is maintained over a longer period. The upper limit of the partial pressure of hydrocarbon is not particularly limited, but is preferably 200 kPa or less, more preferably 100 kPa or less, from the viewpoint that the above-described effects can be obtained more remarkably.

When the dehydrogenation step is performed in a continuous reaction mode in which the raw material gas is continuously supplied, the weight space velocity (hereinafter referred to as “WHSV”) may be 0.1 h ⁻¹ or more, and 0.5 h it may also be ^-1 or more, may be at ^{50h -1} or less, may be ^{20h -1} or less. Here, WHSV is the ratio (supply rate / catalyst mass) of the supply rate (supply amount / time) of hydrocarbons in the raw material gas to the catalyst mass in a continuous reactor. In addition, the usage amount of the raw material gas and the catalyst may be appropriately selected in a more preferable range according to the reaction conditions, the activity of the catalyst, etc., and WHSV is not limited to the above range.

  In the dehydrogenation step, a product containing the unsaturated hydrocarbon is obtained by converting at least a part of the hydrocarbon into the unsaturated hydrocarbon. The product may contain one kind of unsaturated hydrocarbon and may contain two or more kinds of unsaturated hydrocarbons.

  Examples of unsaturated hydrocarbons produced by hydrocarbon dehydrogenation include butene, pentene, hexene, cyclohexene, heptene, octene, nonene, tetrahydroindene, hexahydroindene, indane, indene, butadiene, pentadiene, isoprene, hexadiene, heptadiene. , Octadiene, nonadiene and the like.

  As the reactor used in the dehydrogenation step, various reactors used for a gas phase reaction using a solid catalyst can be used. Examples of the reactor include a fixed bed reactor, a radial flow reactor, and 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 from the viewpoint of equipment cost.

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

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

[Catalyst Synthesis Example 1]
<Preparation of dehydrogenation catalyst A>
And commercial γ- alumina (Nikki manufactured by Shokubai Kasei) 20.0 g, magnesium nitrate hexahydrate (manufactured by Wako Pure Chemical _{Industries, Mg (NO 3) 2 ·} 6H 2 O) and 25.1g of water (approximately 150ml) The dissolved aqueous solution was mixed, and water was removed at about 50 ° C. with an evaporator. Thereafter, the film was dried at 130 ° C. overnight, baked at 550 ° C. for 3 hours, and then baked at 800 ° C. for 3 hours. The obtained calcined product and an aqueous solution in which 25.1 g of magnesium nitrate hexahydrate (manufactured by Wako Pure Chemical Industries, Mg (NO ₃ ) ₂ .6H ₂ O) is dissolved in water (about 150 ml) are mixed, and an evaporator is mixed. The water was removed at about 50 ° C. Thereafter, the film was dried at 130 ° C. overnight, baked at 550 ° C. for 3 hours, and then baked at 800 ° C. for 3 hours. Thereby, an alumina-magnesia carrier having a spinel structure was obtained. The obtained alumina-magnesia carrier was confirmed to have diffraction peaks derived from Mg spinel at 2θ = 36.9, 44.8, 59.4, and 65.3 deg by X-ray diffraction measurement.

The alumina - to magnesia carrier 5.0 g, pre sodium stannate (Kishida Chemical _{Ltd., Na 2 SnO 3 · 3H 2} O) and 0.37g mixed aqueous solution prepared by dissolving in water of 10 ml, the dehydrogenation catalyst is prepared After that, tin was impregnated and supported so that the final amount of tin supported was 2.7% by mass. Thereafter, the film was dried at 130 ° C. overnight, calcined at 550 ° C. for 3 hours, and then repeatedly washed with water. Next, using a dinitrodiammine platinum (II) nitric acid solution (Tanaka Kikinzoku Kogyo, [Pt (NH ₃ ) ₂ (NO ₂ ) ₂ ] / HNO ₃ ), the supported amount of platinum is 1.0 mass%. Platinum was impregnated and supported, dried at 130 ° C. overnight, and calcined at 550 ° C. for 3 hours to obtain a dehydrogenation catalyst A.

(Example 1)
1.0 g of catalyst A was charged into a tubular reactor, and the reaction tube was connected to a fixed bed flow reactor. Next, while flowing a mixed gas of hydrogen and N ₂ (hydrogen: N ₂ = 1: 1 (mol ratio)) at 100 mL / min, the temperature of the reaction tube was increased to 550 ° C. and held at that temperature for 2 hours. . Subsequently, while maintaining the reaction tube at 550 ° C., a mixed gas of N ₂ and steam (water) (N ₂ : steam = 3.0: 1.0 (molar ratio)) was circulated at 138 mL / min for 30 minutes. . Thereafter, a mixed gas (raw material gas) of n-butane and steam (water) was supplied to the reactor, and n-butane in the raw material gas was dehydrogenated. Here, the molar ratio of n-butane and steam in the raw material gas was adjusted to 1.0: 3.2. The feed rate of the raw material gas to the tubular reactor was adjusted to 27 mL / min. The WHSV with respect to the total amount of the catalyst was adjusted to 1.0 h- ¹ . The pressure at the catalyst layer inlet was adjusted to 101 kPa (atmospheric pressure), and the temperature was adjusted to 550 ° C.

  When 60 minutes passed from the start of the reaction, the product (product gas) of the dehydrogenation reaction was collected from the tubular reactor. Further, when 360 minutes passed from the reaction start time, the product (product gas) of the dehydrogenation reaction was collected from the tubular reactor. The reaction start time is the time when the supply of the source gas is started. The product gas collected at each time point was analyzed using a gas chromatograph (TCD-GC) equipped with a thermal conductivity detector. As a result of analysis, it was confirmed that the product gas contained butene and 1,3-butadiene. Based on the gas chromatograph, the butane concentration (unit: mass%) in the product gas collected at each time point was quantified.

From the butane concentration in the product gas, the butane conversion rate at the time of 60 minutes and at the time of 360 minutes was calculated. In addition, the butane conversion rate at the time of 60 minutes and the time of 360 minutes is defined by the following formulas (1) and (2), respectively.
R ₁ = (1−M ₁ / M ₀ ) × 100 (1)
R ₂ = (1-M ₂ / M ₀ ) × 100 (2)
R ₁ in the formula (1) is the butane conversion rate after 60 minutes, M ₀ is the number of moles of n-butane in the raw material gas, and M ₁ is in the product gas after 60 minutes. The number of moles of n-butane. R ₂ in Formula (2) is the butane conversion rate at the time when 360 minutes have elapsed, M ₀ is the number of moles of n-butane in the raw material gas, and M ₂ is the product gas at the time when 360 minutes have elapsed. The number of moles of n-butane.

As a result, the butane conversion was 68.5% after 60 minutes from the start of the reaction and 62.7% after 360 minutes, and the latter was divided by the former (R _2). / R ₁ ) was 0.91.

(Example 2)
Except that the pressure at the catalyst layer inlet was adjusted to 150 kPa, n-butane dehydrogenation reaction and product gas analysis were performed in the same manner as in Example 1. The butane conversion rate was 53.7% after 60 minutes from the start of the reaction, and 57.3% when 360 minutes had elapsed. The latter was divided by the former (R ₂ / R _1). ) Was 1.07.

(Comparative Example 1)
Except that the pressure at the catalyst layer inlet was adjusted to 50 kPa (reduced pressure), n-butane dehydrogenation reaction and analysis of the generated gas were performed in the same manner as in Example 1. The butane conversion was 63.1% after 60 minutes from the start of the reaction, and 45.6% after 360 minutes. The latter was divided by the former (R ₂ / R _1). ) Was 0.72.

(Comparative Example 2)
1.0 g of catalyst A was charged into a tubular reactor, and the reaction tube was connected to a fixed bed flow reactor. Next, while flowing a mixed gas of hydrogen and N ₂ (hydrogen: N ₂ = 1: 1 (mol ratio)) at 100 mL / min, the temperature of the reaction tube was increased to 550 ° C. and held at that temperature for 2 hours. . Subsequently, while maintaining the reaction tube at 550 ° C., a mixed gas of N ₂ and steam (water) (N ₂ : steam = 3.0: 1.0 (molar ratio)) was circulated at 138 mL / min for 30 minutes. . Thereafter, a mixed gas (raw material gas) of n-butane, N ₂ and steam (water) was supplied to the reactor, and n-butane in the raw material gas was dehydrogenated. Here, the molar ratio of n-butane, N ₂ and steam in the raw material gas was adjusted to 1.0: 5.3: 3.2. The feed rate of the raw material gas to the tubular reactor was adjusted to 61 mL / min. The WHSV with respect to the total amount of the catalyst was adjusted to 1.0 h- ¹ . The pressure at the catalyst layer inlet was adjusted to 101 kPa (atmospheric pressure), and the temperature was adjusted to 550 ° C.

As a result, the butane conversion rate was 72.7% after 60 minutes from the start of the reaction, and 57.7% after 360 minutes. The latter was divided by the former (R _2). / R ₁ ) was 0.79.

  Table 1 shows the results of Examples 1-2 and Comparative Examples 1-2.

Claims (5)

Comprising a step of dehydrogenating at least a part of the hydrocarbon by flowing a raw material gas containing a hydrocarbon having 4 to 9 carbon atoms through a reactor having a catalyst layer filled with a dehydrogenation catalyst,
The dehydrogenation catalyst has a carrier containing aluminum and a supported metal supported on the carrier;
The supported metal includes tin and platinum;
At the inlet of the catalyst layer, the pressure is 101 kPa or more, and the partial pressure of the hydrocarbon is 17 kPa or more.
A method for producing unsaturated hydrocarbons.   The production method according to claim 1, wherein at the inlet of the catalyst layer, the pressure is 130 kPa or more and the partial pressure of the hydrocarbon is 30 kPa or more. The atomic ratio (Sn / Pt) of tin and platinum in the dehydrogenation catalyst is 3.0 or more and 6.0 or less,
The production method according to claim 1 or 2, wherein the platinum content in the dehydrogenation catalyst is 0.6 mass% or more and 3.0 mass% or less based on the total amount of the dehydrogenation catalyst.   The production method according to any one of claims 1 to 3, wherein the dehydrogenation catalyst is a catalyst in which tin and platinum are supported on the support using a metal source not containing a chlorine atom. The manufacturing method as described in any one of Claims 1-4 whose temperature in the inlet_port | entrance of the said catalyst layer is 500 degreeC or more.