JP2006001894A - Method for producing dehydrogenated compound and catalyst filling method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a dehydrogenated compound which can inhibit the lowering of the hydrogen conversion in the oxidation step and can inhibit the formation of carbon dioxide, and a catalyst filling method therefor. <P>SOLUTION: This method for producing a dehydrogenated compound uses a reaction apparatus having both a dehydrogenation catalyst filled layer and an oxidation catalyst filled layer and renders the amount of the dehydrogenation catalyst mixed into the oxidation catalyst filled layer less than 1.0 wt.%. This catalyst filling method comprises settling down the dust of the dehydrogenation catalyst after filling the dehydrogenation catalyst and then filling the oxidation catalyst. Further, the catalyst filling method comprises filling the dehydrogenation catalyst at least after cutting the connection between the oxidation catalyst filling section or the oxidation catalyst filled layer formed and the dehydrogenation catalyst filling section. The method for producing a dehydrogenated compound uses a reaction apparatus in which a dehydrogenation catalyst filled layer and an oxidation catalyst filled layer are formed by these catalyst filling methods. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention comprises a dehydrogenation step in which a raw material hydrocarbon compound is brought into contact with a dehydrogenation catalyst, and a dehydrogenation reaction mixed gas obtained from the step is brought into contact with an oxidation catalyst in the presence of an oxygen-containing gas. And an oxidation process for selectively oxidizing hydrogen in the mixed gas, and a catalyst filling method therefor.

  A process for producing a dehydrogenated compound by dehydrogenating raw material hydrocarbons, for example, a process for producing styrene by dehydrogenating ethylbenzene has been widely practiced industrially. However, in general, the dehydrogenation reaction is strongly constrained by equilibrium, and since the dehydrogenation reaction is an endothermic reaction, the reaction temperature in an adiabatic reactor decreases with the progress of the reaction. Therefore, it has been proposed to combine an oxidation step of selectively oxidizing hydrogen generated by a dehydrogenation reaction with an oxidation catalyst in the dehydrogenation step.

For example, Patent Document 1 proposes a method for producing a dehydrogenated compound in which a plurality of dehydrogenation steps and an oxidation step are combined. In addition, various methods for improving the oxidation catalyst and the oxidation process have been proposed. For example, Patent Document 2 proposes an oxidation catalyst having stable performance for a long time. Further, it is reported in Non-Patent Document 1 that the reaction activity decreases only when there is a small amount of carbon dioxide during the steady-state reaction of the dehydrogenation catalyst, and the reaction activity further decreases as the partial pressure of carbon dioxide increases. In this regard, Patent Document 3 proposes a method for suppressing the generation of carbon dioxide on the oxidation catalyst by removing in advance alkaline substances in the reaction mixture supplied to the oxidation step.
Japanese Patent Publication No. 5-38800. JP 2000-342969. Japanese Patent Application Laid-Open No. 11-80045. Catalyst, 29, (8), 641 (1987).

  However, according to the study by the present inventors, despite the production of dehydrogenated compounds using these oxidation catalysts and methods for improving the oxidation process, it is not always possible to obtain satisfactory reaction results. There was found.

  The present invention has been made in view of the above-mentioned circumstances, and the object thereof is a dehydrogenation process in which a raw material hydrocarbon compound is brought into contact with a dehydrogenation catalyst to perform a dehydrogenation reaction, and a dehydrogenation reaction mixed gas obtained from the process. In a method for producing a dehydrogenated compound comprising contacting an oxygen catalyst with an oxidation catalyst in the presence of an oxygen-containing gas to selectively oxidize hydrogen in the mixed gas, a reduction in hydrogen conversion rate in the oxidation step is suppressed. Another object of the present invention is to provide a method for producing a dehydrogenated compound capable of suppressing the production of carbon dioxide, and a catalyst filling method therefor.

  As a result of intensive studies to solve the above problems, the present inventors have inevitably mixed a dehydrogenation catalyst into the oxidation catalyst charged in the reactor in the oxidation step, which reduces the hydrogen conversion rate, The present inventors have found that the object can be achieved by affecting the production of carbon dioxide and reducing the amount of the dehydrogenation catalyst mixed in the oxidation catalyst. That is, the gist of the present invention is to bring a raw material hydrocarbon compound into contact with a dehydrogenation catalyst to cause a dehydrogenation reaction, thereby generating a dehydrogenation reaction mixture gas containing the dehydrogenation compound, the unreacted raw material hydrocarbon compound, and hydrogen. A dehydrogenation step, and a dehydrogenation step of contacting the dehydrogenation reaction mixed gas obtained from the step with an oxidation catalyst in the presence of an oxygen-containing gas to selectively oxidize hydrogen in the mixed gas. In the method for producing a compound, a reactor having both a dehydrogenation catalyst packed bed and an oxidation catalyst packed bed, wherein the amount of the dehydrogenation catalyst mixed in the oxidation catalyst packed bed is less than 1.0% by weight. A method for producing a dehydrogenated compound to be used.

  Further, the gist of the present invention is to form a dehydrogenation catalyst packed bed by filling a dehydrogenation catalyst when forming a dehydrogenation catalyst packed layer and an oxidation catalyst packed layer in a reactor for producing a dehydrogenated compound. Then, after the dust of the dehydrogenation catalyst has subsided, a catalyst filling method for filling the oxidation catalyst to form an oxidation catalyst packed bed and a dehydrogenation catalyst packed bed in the reactor for producing the dehydrogenated compound When forming the oxidation catalyst packed bed, at least the formation of the dehydrogenation catalyst packed bed by filling the dehydrogenation catalyst is cut off between the oxidation catalyst packed part or the formed oxidation catalyst packed bed and the dehydrogenation catalyst packed part. And a reaction apparatus in which a dehydrogenation catalyst packed bed and an oxidation catalyst packed bed are formed in the reaction apparatus by the catalyst filling method when producing the dehydrogenated compound from the raw material hydrocarbon compound. Use Method for producing hydrogen compounds, consists in.

  According to the present invention, a dehydrogenation step in which a raw material hydrocarbon compound is brought into contact with a dehydrogenation catalyst to perform a dehydrogenation reaction, and a dehydrogenation reaction mixed gas obtained from the step is brought into contact with an oxidation catalyst in the presence of an oxygen-containing gas. In the method for producing a dehydrogenation compound comprising an oxidation step of selectively oxidizing hydrogen in the mixed gas, dehydrogenation capable of suppressing a decrease in hydrogen conversion rate in the oxidation step and suppressing generation of carbon dioxide It is possible to provide a method for producing a compound and a catalyst filling method therefor.

The present invention will be described in detail below, but the description of the constituent elements described below is a representative example of the embodiment of the present invention, and is not specified by these contents.
Although it does not specifically limit as a raw material hydrocarbon compound used for the manufacturing method of the dehydrogenation compound of this invention, It is preferable that it is an aromatic ring compound which has a hydrocarbon chain which can be dehydrogenated, Specifically, for example, Ethylbenzene, diethylbenzene, ethylnaphthalene, diethylnaphthalene and the like, and ethylbenzene and ethylnaphthalene are particularly preferable. These can also use 2 or more types together. Moreover, when these raw material hydrocarbon compounds are solid, they can also be used as a solution dissolved in a solvent or as a melt melted at a temperature higher than the melting point.

  The method for producing a dehydrogenation compound of the present invention comprises a dehydrogenation step in which the raw material hydrocarbon compound is brought into contact with a dehydrogenation catalyst and a dehydrogenation reaction, and a dehydrogenation reaction mixed gas obtained from the step is coexistent with an oxygen-containing gas. And an oxidation step of selectively oxidizing hydrogen in the mixed gas by contacting with an oxidation catalyst below.

  Here, in the dehydrogenation step in which the raw material hydrocarbon compound is brought into contact with a dehydrogenation catalyst to perform a dehydrogenation reaction, the dehydrogenation catalyst is not particularly limited as long as it has its function, and conventionally known iron and In addition, a dehydrogenation catalyst containing a metal of Group 1 or 2 and / or Group 2 of the periodic table, specifically, for example, a metal such as lithium, sodium, potassium, beryllium, magnesium, calcium, etc. as a main active component is used. The latter metal is preferably potassium.

  In addition, the dehydrogenation reaction in the dehydrogenation step is performed at a temperature in the range of 500 to 800 ° C. and an absolute pressure in the range of 0.05 to 10 atm, for example, when styrene is produced using ethylbenzene as a raw material hydrocarbon. By the dehydrogenation reaction, in the dehydrogenation step, a dehydrogenation reaction mixture gas containing a dehydrogenation compound, an unreacted raw material hydrocarbon compound, and hydrogen is generated. In this dehydrogenation reaction, water vapor can also coexist. In that case, in the dehydrogenation process, the raw material hydrocarbon compound is turned into a gaseous form by steam that is heated to the reaction temperature, and the dehydrogenation reaction results in the dehydrogenation compound. Then, a dehydrogenation reaction mixed gas containing unreacted raw material hydrocarbon compound, hydrogen, and water vapor is generated.

  In the oxidation step in which the dehydrogenation reaction mixed gas obtained in the dehydrogenation step is brought into contact with an oxidation catalyst in the presence of an oxygen-containing gas to selectively oxidize hydrogen in the mixed gas, as the oxygen-containing gas, A gas containing 1 to 100% of molecular oxygen is used. Specifically, for example, air, oxygen-enriched air, oxygen, air diluted with an inert gas, oxygen diluted with an inert gas, and the like are preferable. Used. Also, water vapor can be included in the oxygen-containing gas.

  Further, the oxidation catalyst in the oxidation step is not particularly limited as long as it is a catalyst that selectively oxidizes hydrogen with an oxygen-containing gas, but preferably contains a platinum group metal on a heat-resistant inorganic support. It is an oxidation catalyst. Here, as the heat-resistant inorganic carrier, any carrier generally used as a catalyst carrier can be used. For example, metals such as aluminum, silicon, titanium, germanium, niobium, molybdenum, tin, tantalum, tungsten, etc. An inorganic carrier containing atoms is used. Among them, an inorganic carrier containing at least one metal atom selected from the group consisting of tantalum, aluminum, titanium, and niobium is resistant to heat resistance and dehydrogenation reaction (combustion reaction). Is less). These inorganic carriers are generally prepared using aluminum oxide, silicon oxide, titanium oxide, germanium oxide, niobium oxide, molybdenum oxide, tin oxide, tantalum oxide, tungsten oxide, or the like, preferably tantalum oxide, oxide Aluminum, titanium oxide, and niobium oxide are used. Two or more kinds of these heat-resistant inorganic carriers may be prepared. When two or more kinds are used, the existence form of the oxide used for the preparation is a complex oxide. Alternatively, a mixture of the oxides used may be used.

  As the oxidation catalyst, a catalyst having a platinum group metal is preferably used. Here, the platinum group metal is an element of the group consisting of ruthenium, rhodium, palladium, osmium, iridium, and platinum of Groups 8 to 10 of the periodic table, and these may be included alone or 2 More than species may be included. Of these, platinum and / or palladium are preferred.

  As the temperature of the oxidation step, if the temperature is too high, the hydrogen selectivity tends to decrease and the combustion of hydrocarbons tends to increase. If the temperature is too low, the activity of oxidizing hydrogen decreases. there's a possibility that. Therefore, it is preferably performed at a temperature in the range of 300 to 800 ° C, more preferably at a temperature in the range of 400 to 700 ° C.

  In a normal oxidation reaction, a method of supplying excess oxygen and a method of consuming all oxygen are performed. In particular, it is known that coking occurs on the catalyst after all the oxygen is consumed in a reaction in which hydrocarbons and oxygen are introduced into the reactor and reacted to consume all the oxygen. In the oxidation catalyst used in the present invention, when all the oxygen is consumed, coking occurs on the subsequent catalyst. However, the selectivity for selectively oxidizing hydrogen does not deteriorate, and the oxygen concentration is increased by increasing the oxygen concentration. Caulking is also possible. Therefore, it can be performed by either a method of supplying oxygen excessively or a method of consuming all oxygen, but usually a method of consuming all oxygen is preferably used.

  The method for producing a dehydrogenation compound of the present invention is applicable to any process as long as it includes the dehydrogenation step and the oxidation step. Typical processes include the following processes. For example, in the first-stage reaction layer filled with the dehydrogenation catalyst, the raw hydrocarbon compound is brought into contact with the dehydrogenation catalyst and subjected to the dehydrogenation reaction, and then the dehydrogenation compound, unexposed from the first-stage reaction layer is discharged. The raw material hydrocarbon compound of the reaction and the dehydrogenation reaction mixed gas containing hydrogen are sent to the second stage reaction layer filled with an oxidation catalyst for selectively oxidizing hydrogen in the dehydrogenation reaction mixed gas. In the two-stage reaction layer, hydrogen is selectively oxidized by the oxygen-containing gas newly introduced in contact with the oxidation catalyst. As a result, the temperature lowered by the dehydrogenation reaction, which is the first endothermic reaction, is raised by the exothermic reaction, and the hydrogen is consumed to remove the equilibrium limitation of the dehydrogenation reaction. Further, when the gas emitted from the second-stage reaction layer is sent to a third-stage reaction layer filled with a dehydrogenation catalyst similar to the first-stage reaction layer, an unreacted hydrocarbon compound is dehydrogenated. Since the temperature necessary for the reaction has already been recovered in the second stage reaction layer and the equilibrium constraint has been removed, a higher yield can be obtained in the third stage reaction layer. If necessary, the reaction can be carried out by further adding a combination of these selective oxidation reaction and dehydrogenation reaction.

  One specific example of the representative process is an example of producing styrene by an ethylbenzene dehydrogenation process. In this dehydrogenation process, for example, a mixed gas of ethylbenzene and water vapor is sent to the first stage reaction layer filled with a dehydrogenation catalyst containing iron and alkali metal as main active components, and a temperature in the range of 500 to 800 ° C., absolute The dehydrogenation reaction is performed at a pressure in the range of 0.05 to 10 atmospheres. After that, the produced styrene monomer, unreacted ethylbenzene, hydrogen, and steam mixed gas are sent to the second-stage reaction layer filled with the oxidation catalyst to selectively oxidize hydrogen, and then this reaction gas is The styrene monomer is obtained in a high yield by sending it to the third-stage reaction layer filled with the dehydrogenation catalyst and dehydrogenating the unreacted ethylbenzene.

  In the above method for producing a dehydrogenation compound, in the present invention, the dehydrogenation catalyst packed bed and the oxidation catalyst packed bed are combined, and the amount of the dehydrogenation catalyst mixed in the oxidation catalyst packed bed is 1.0. It is characterized by using a reactor having a weight of less than%. If the amount of the dehydrogenation catalyst contained as an impurity in the oxidation catalyst is 1.0% by weight or more, the performance of the oxidation catalyst will deteriorate. The amount of the dehydrogenation catalyst is preferably 0.5% by weight or less.

  The reaction apparatus applied to the method for producing a dehydrogenation compound of the present invention is not particularly limited as long as a dehydrogenation catalyst packed bed and an oxidation catalyst packed bed can be formed. Examples include a reactor in which a dehydrogenation catalyst packed bed and an oxidation catalyst packed bed are separated by a catalyst holding screen.

  In the reactor, the reason why the dehydrogenation catalyst is contained as an impurity in the oxidation catalyst charged in the reaction device is that the present inventors have described catalyst powder when the dehydrogenation catalyst and the oxidation catalyst are filled in the reaction device. It has been found that catalyst dust is produced by the conversion and is mixed into the other catalyst layer. In addition, as one aspect of the solution, after the dehydrogenation catalyst is filled, the dehydrogenation catalyst dust is subsided and then the oxidation catalyst is filled to suppress the dehydrogenation catalyst from being mixed into the oxidation catalyst. It was possible to keep the amount of the dehydrogenation catalyst in the oxidation catalyst within the above range. At that time, the time from the filling of the dehydrogenation catalyst to the start of the filling of the oxidation catalyst varies depending on the capacity of the reactor, but is usually 5 minutes to 15 hours, preferably 5 minutes to 12 hours, more preferably 10 minutes to About 8 hours. In general, the object of the present invention is often achieved within a few hours, but in the actual process, there is a case where the work is not performed at night, and in this case, the time until the start of the filling of the oxidation catalyst may become long. is there. At that time, after forming the dehydrogenation catalyst packed bed, it is also effective to blow the dehydrogenation catalyst packed bed with dry air or nitrogen gas to blow off the adhered powder.

  As another different embodiment of the method for forming the catalyst layer in the reaction apparatus for carrying out the method for producing the dehydrogenated compound of the present invention, the formation of the dehydrogenated catalyst packed layer by at least charging of the dehydrogenated catalyst is performed. It can also be suppressed by cutting between the oxidation catalyst filling portion or the formed oxidation catalyst filling layer and the dehydrogenation catalyst filling portion, and the amount of the dehydrogenation catalyst in the oxidation catalyst is kept within the above range. I was able to. Examples of the edge cutting material at that time include a resin sheet and a metal sheet.

  As a specific example of this latter aspect, for example, after cutting between the oxidation catalyst filling portion and the dehydrogenation catalyst filling portion, the oxidation catalyst is filled to form an oxidation catalyst layer, and then the dehydrogenation catalyst is filled. When the dehydrogenation catalyst layer is formed by cutting the gap between the oxidation catalyst filling portion and the dehydrogenation catalyst filling portion, the dehydrogenation catalyst is filled to form the dehydrogenation catalyst layer, and then the oxidation catalyst is filled. In the case of forming an oxidation catalyst layer, or after forming an oxidation catalyst packed layer by filling the oxidation catalyst, the dehydrogenation catalyst filling portion is cut off, and then the dehydrogenation catalyst is filled and the dehydrogenation catalyst is filled. When forming a packed bed, etc. are mentioned.

  Further, in the latter embodiment, when the dehydrogenation catalyst packed bed and the oxidation catalyst packed bed are formed in the reactor, for example, when only the dehydrogenated catalyst deteriorated by performing the production operation is replaced, By removing the dehydrogenation catalyst from the dehydrogenation catalyst packed bed that has been cut so that dust does not substantially pass through the space between the two, the dehydrogenation catalyst amount in the oxidation catalyst is within the above range by filling the dehydrogenation catalyst. Can be stopped.

  By producing a dehydrogenated compound using a reactor in which a dehydrogenation catalyst packed bed and an oxidation catalyst packed bed are formed by these catalyst filling methods, it is possible to suppress a decrease in hydrogen conversion rate in the oxidation step. , Generation of carbon dioxide can be suppressed.

  The reaction mixture thus obtained contains a dehydrogenated compound, an unreacted raw material hydrocarbon compound, hydrogen, steam, etc., but usually it is subjected to operations such as cooling, gas-liquid separation, oil-water separation, and purification steps by distillation. The dehydrogenated compound is isolated as a product. At that time, the unreacted raw material hydrocarbon may be recycled to the reactor as a raw material.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example, this invention is not limited by a following example, unless the summary is exceeded.

Example 1
<Preparation of oxidation catalyst>
26 g of water was added to 70 g of niobium pentoxide (Nb ₂ O ₅ ) and kneaded. A cylindrical molded product having a diameter of 3 mm formed by extrusion molding this kneaded product was dried at 120 ° C. for 3 hours, and then at 900 ° C. After baking for 3 hours, it was cut into lengths of 1 to 5 mm to form pellets. Subsequently, the pellet was immersed in 21 ml of a chloroplatinic acid (H ₂ PtCl ₆ .6H ₂ O) aqueous solution containing 0.14 g of platinum, and then dried at 60 ° C. under reduced pressure for 1 hour using a rotary evaporator. It dried at 120 degreeC with the dryer for 3 hours, and was baked at 650 degreeC under air for 3 hours after that. Subsequently, after immersing in 21 ml of an aqueous potassium carbonate (K ₂ CO ₃ ) solution containing 0.21 g of potassium, it was dried for 1 hour at 60 ° C. under reduced pressure on a rotary evaporator, and further 3 hours at 120 ° C. in a dryer. The catalyst was dried and then calcined at 650 ° C. for 3 hours in air to prepare an oxidation catalyst of platinum / potassium / niobium oxide composed of 0.2% by weight of platinum, 0.3% by weight of potassium and the other niobium oxide.

<Preparation of dehydrogenation catalyst>
A dehydrogenation catalyst was prepared based on Example 2 of JP-T-2002-509790. That is, 600 g of iron oxide (Fe ₂ O ₃ ), 111 g of potassium carbonate (K ₂ CO ₃ ), 10 g of methyl cellulose, 20 g of corn starch and 180 g of water were added and kneaded. A molded product obtained by extruding the kneaded material into a cylindrical shape having a diameter of 3 mm was dried at 120 ° C. for 3 hours and baked at 600 ° C. for 3 hours. This operation was repeated until a catalyst amount required for the following dropping was obtained. 5,000 g of the dehydrogenation catalyst thus obtained was dropped in a tube of a reactor model having a tube diameter of 38.9 mm and a length of 10 m, and received at the bottom by a SUS316 plate. In the dropped dehydrogenation catalyst, the amount of powder having a diameter of 0.85 mm or less was 0.97% by weight. This is designated as dehydrogenation catalyst A.

  As a model test for catalyst filling, the dehydrogenation catalyst A prepared above was filled from the outside upper part of a mesh tube of 8 cm × 8 cm in size and 20 cm in height formed by a mesh with a mesh spacing of 2 mm and left to stand for 30 minutes. After that, it was visually confirmed that the scattering of dust in the oxidation catalyst filling portion was settled, and the oxidation catalyst prepared above was filled on the outside of the cylinder. The filled oxidation catalyst was extracted and sieved with a sieve having an opening diameter of 0.85 mm. As a result, 0.2% by weight of red powder derived from the dehydrogenation catalyst was mixed.

Example 2
After filling the inside of the mesh tube used in Example 1 with the oxidation catalyst prepared above, a polyethylene sheet was placed on the mesh portion and the dehydrogenation catalyst filling portion was cut off, The prepared dehydrogenation catalyst A was filled, and then the polyethylene sheet was removed. When the filled oxidation catalyst was extracted and the presence of the catalyst derived from the dehydrogenation catalyst mixed therein was confirmed, no contamination was observed.

Comparative Example 1
The oxidation catalyst was filled in the same manner as in Example 1 except that the standing time after filling the dehydrogenation catalyst A was 30 seconds. The charged oxidation catalyst was extracted, and the amount of catalyst derived from the dehydrogenation catalyst mixed therein was measured to be 1.1% by weight.

Comparative Example 2
The dehydrogenation catalyst A was filled in the same manner as in Example 2 except that the polyethylene sheet was not used after filling the oxidation catalyst. The charged oxidation catalyst was extracted, and the amount of the catalyst derived from the dehydrogenation catalyst mixed therein was measured and found to be 1.4% by weight.

Example 3
<Preparation of dehydrogenation catalyst>
A dehydrogenation catalyst having a composition of 11.2% by weight of potassium oxide (K ₂ O) and 88.8% by weight of iron oxide (Fe ₂ O ₃ ) based on Comparative Example 1 of JP-T-2002-509790 A dehydrogenation catalyst B is prepared by mixing potassium carbonate (K ₂ CO ₃ ) and iron oxide (Fe ₂ O ₃ ) in an amount necessary for synthesis while crushing in a mortar and then calcining at 600 ° C. for 3 hours. did.

By mixing 0.5 wt% of the dehydrogenation catalyst B prepared above into the oxidation catalyst prepared above into a quartz reaction tube having an inner diameter of 6.7 mm filled with quartz chips having substantially the same particle size at the top and bottom. After charging 2 ml of the prepared oxidation catalyst, the temperature was raised to 600 ° C. under nitrogen flow, and then a mixed gas of ethylbenzene, styrene monomer, water, hydrogen, oxygen, and nitrogen (molar ratio; ethylbenzene / styrene monomer / water / hydrogen). /Oxygen/nitrogen=1/0.87/17.6/0.65/0.17/1.28) was introduced into the reaction tube with a space velocity in terms of gas supplied to the catalyst of 8448 h ^−1. An oxidation reaction was performed. As a result of gas chromatograph analysis of the gas at the outlet of the reaction tube and the liquid trapped in the liquid receiver, the hydrogen conversion rate was 37.4 mol% and the oxygen conversion rate was 100 mol%. The carbon dioxide production rate was 0.09 mol%.
Carbon dioxide production rate (mol%) = [number of moles of produced carbon dioxide × 8 / (number of moles of supplied ethylbenzene + number of moles of fed styrene monomer)] × 100

Example 4
The oxidation reaction was performed in the same manner as in Example 3 except that the dehydrogenation catalyst B prepared above was not mixed into the oxidation catalyst prepared above. As a result, the hydrogen conversion rate was 37.5 mol%, the oxygen conversion rate was 100 mol%, and the carbon dioxide production rate was 0.08 mol%.

Comparative Example 3
The oxidation reaction was performed in the same manner as in Example 3 except that 1.0% by weight of the dehydrogenation catalyst B prepared above was mixed with the oxidation catalyst prepared above. As a result, the hydrogen conversion rate was 35.2 mol%, the oxygen conversion rate was 100 mol%, and the carbon dioxide production rate was 0.12 mol%.

Comparative Example 4
The oxidation reaction was performed in the same manner as in Example 3 except that 5.0% by weight of the dehydrogenation catalyst B prepared above was mixed with the oxidation catalyst prepared above. As a result, the hydrogen conversion rate was 27.2 mol%, the oxygen conversion rate was 100 mol%, and the carbon dioxide production rate was 0.19 mol%.

  The results of the oxidation reaction in Examples 3 and 4 and Comparative Examples 3 and 4 are summarized in Table 1.

Claims (8)

A dehydrogenation step of bringing a raw material hydrocarbon compound into contact with a dehydrogenation catalyst to cause a dehydrogenation reaction to produce a dehydrogenation compound, an unreacted raw material hydrocarbon compound, and a dehydrogenation reaction mixed gas containing hydrogen; In the method for producing a dehydrogenated compound, the dehydrogenation reaction mixed gas is brought into contact with an oxidation catalyst in the presence of an oxygen-containing gas to selectively oxidize hydrogen in the mixed gas. A dehydrogenation comprising a catalyst packed bed and an oxidation catalyst packed bed, wherein the amount of the dehydrogenation catalyst mixed in the oxidized catalyst packed bed is less than 1.0% by weight. Compound production method. 2. The dehydrogenation catalyst contains at least iron and a metal of Group 1 or / and 2 of the periodic table, and the oxidation catalyst is one in which at least a platinum group metal is supported on a heat-resistant inorganic support. A method for producing the dehydrogenated compound according to 1. The method for producing a dehydrogenated compound according to claim 2, wherein the heat-resistant inorganic carrier of the oxidation catalyst contains at least one metal atom selected from the group consisting of tantalum, aluminum, titanium, and niobium. The method for producing a dehydrogenated compound according to any one of claims 1 to 3, wherein a reaction temperature in the oxidation step is 300 ° C or higher and 800 ° C or lower. The method for producing a dehydrogenated compound according to any one of claims 1 to 4, wherein the raw material hydrocarbon compound is ethylbenzene and / or diethylbenzene. When the dehydrogenation catalyst packed bed and the oxidation catalyst packed bed are formed in the reactor for producing the dehydrogenated compound, the dehydrogenated catalyst packed bed is formed by filling the dehydrogenated catalyst and then the dehydrogenated catalyst dust. A catalyst filling method characterized by forming an oxidation catalyst packed layer by filling an oxidation catalyst after the sedation has subsided. When forming the dehydrogenation catalyst packed bed and the oxidation catalyst packed bed in the reaction apparatus for producing the dehydrogenated compound, at least the formation of the dehydrogenated catalyst packed bed by filling the dehydrogenation catalyst, the formation part of the oxidation catalyst or the formation A catalyst filling method, which is carried out after cutting the gap between the oxidized catalyst packed bed and the dehydrogenated catalyst packed portion. When producing a dehydrogenated compound from a raw material hydrocarbon compound, a reactor in which a dehydrogenated catalyst packed bed and an oxidation catalyst packed bed are formed in the reactor by the catalyst filling method according to claim 6 or 7 is used. The method for producing a dehydrogenated compound according to any one of claims 1 to 5.