Catalyst for producing high calorific value fuel gas, method for producing the same, and method for producing high calorific value fuel gas

Abstract

To ensure sufficient economic viability as a carbon-neutral city gas production process, we provide a catalyst that exhibits a high conversion rate to hydrocarbons at lower temperatures and can be easily prepared using inexpensive constituent materials. [Solution] The catalyst for producing high-calorific value fuel gas contains cobalt supported on an inorganic oxide carrier mainly composed of activated alumina, and lanthanum or manganese, wherein the amount of cobalt supported is 5.0 parts by mass or more and 20 parts by mass or less per 100 parts by mass of the inorganic oxide carrier, if lanthanum is supported, the amount of lanthanum supported is 1.0 part by mass or more and 10 parts by mass or less per 100 parts by mass of the inorganic oxide carrier, and if manganese is supported, the amount of manganese supported is 1.0 part by mass or more and 10 parts by mass or less per 100 parts by mass of the inorganic oxide carrier.

Description

[Technical Field]

[0001] The present invention relates to a technology for producing a high-calorific value fuel gas having a higher calorific value per unit volume than methane from a mixed gas containing at least one of carbon monoxide or carbon dioxide and hydrogen, and more specifically, to a technology for producing a fuel gas mainly composed of methane, and also containing ethane, propane, and butane. [Background technology]

[0002] In recent years, carbon-neutral fuels, which do not substantially increase the concentration of carbon dioxide in the atmosphere when burned, have been attracting attention from the perspective of combating global warming.

[0003] Methane can be obtained by recovering carbon dioxide from exhaust gases generated in industrial processes and thermal power plants, and then reacting the resulting hydrogen, obtained through electrolysis using electricity from renewable energy sources such as solar and wind power, on a methane catalyst. Alternatively, electrolysis of a mixed gas consisting of carbon dioxide and water vapor using a solid oxide electrolytic cell (SOEC) yields a gas (synthesis gas) mainly composed of hydrogen and carbon monoxide, which can then be reacted on a methane catalyst to produce methane. Since methane obtained by these methods does not generate additional carbon dioxide when burned, it can be considered a carbon-neutral fuel that does not contribute to global warming.

[0004] The methane reaction (Equation 1) that produces methane by reacting carbon monoxide with hydrogen, and the methane reaction (Equation 2) that produces methane by reacting carbon dioxide with hydrogen, are both well known. CO+3H2→ CH4+H2O (Formula 1) CO2+4H2→ CH4+2H2O (Formula 2)

[0005] The methanation reaction has long been used to remove carbon monoxide and carbon dioxide from hydrogen used for ammonia synthesis, and catalysts supported with materials such as Ni and Ru are known to exhibit high activity.

[0006] The methane reaction, which produces methane by reacting carbon monoxide or carbon dioxide with hydrogen, is an industrially established technology, but there are still challenges in obtaining fuel gas of a quality suitable for use as a raw material for city gas.

[0007] Natural gas is commonly used as a raw material for city gas, and its main component is methane, with small amounts of ethane, propane, and butane. The composition of natural gas varies depending on the gas field, and its calorific value is not constant. When the calorific value fluctuates, the flammability of the gas changes, which may cause the performance of gas-consuming equipment to become unstable. Therefore, in gas production in Japan's city gas industry, liquefied petroleum gas (LPG), which mainly consists of propane or butane, is added to the raw material natural gas (mostly vaporized liquefied natural gas) to adjust the calorific value to keep it within a certain range. In Japan, the volume of 1 m³ at standard conditions (0°C, 101.325 kPa) is... 3 In many cases, city gas with a higher heating value (calorific value) of 45 MJ is manufactured and supplied.

[0008] Under normal reaction conditions, the only hydrocarbon produced by the methanation reaction is methane; hydrocarbons with two or more carbon atoms, such as ethane and propane, are not included. The calorific value of methane is 39.7 MJ / m³. 3 Therefore, the typical city gas concentration is 45 MJ / m³. 3 To adjust the calorific value, it is necessary to add a large amount of LPG, which is economically disadvantageous. Furthermore, LPG, which can be considered carbon neutral, has limited availability and is difficult to obtain.

[0009] Various technologies have been investigated for producing high-calorific value fuel gases, primarily composed of methane and containing other saturated hydrocarbons as byproducts, through the reaction of carbon oxides (carbon monoxide and carbon dioxide) with hydrogen.

[0010] Patent Document 1 discloses a catalyst for producing high-calorie gas, which is characterized in that a carrier made of silica or alumina supports a combination of manganese oxide and a platinum group metal on an iron group metal as a catalyst substrate. Although it is described that cobalt and iron are particularly preferred as the iron group metal, the disclosure of experimental results is limited to a catalyst supporting three components of ruthenium, cobalt and manganese on a silica or alumina carrier. In the preparation of the catalyst described in Patent Document 1, in the step of supporting ruthenium, a treatment of exposing to a high-concentration ammonia-containing gas is adopted, and there remains a concern about the economy of the catalyst preparation process.

[0011] Patent Document 2 discloses a method for producing a hydrocarbon mixed gas having a high calorie from a mixed gas containing carbon monoxide and hydrogen in the presence of a catalyst. As the catalyst, [A] a first catalyst containing an active component composed of an iron group metal and manganese oxide, or an iron group metal, manganese oxide and a platinum group metal, and a metal oxide as a carrier, and [B] a second catalyst composed of a pentasil-type zeolite ion-exchanged with hydrogen and / or a Group VIII metal are used. A method for producing high-calorie gas characterized by using a mixed catalyst is disclosed. According to the catalyst described in Patent Document 2, it is shown that C2-C4 hydrocarbons can be obtained in a high yield. However, since the synthesis reaction of hydrocarbons by hydrogenation of carbon monoxide and carbon dioxide involves the generation of water vapor, the catalyst will be exposed to a high-concentration water vapor atmosphere, and there remains a concern about the stability over time of the second catalyst composed of pentasil-type zeolite under such conditions.

[0012] Patent Document 3 discloses a catalyst for producing high-calorie gas in which ruthenium and an iron group element are supported on a metal oxide carrier and the ruthenium dispersion degree is 20% or more. When this catalyst is used, due to the cooperative action of ruthenium and the iron group element, at a relatively low temperature and under conditions with a high carbon monoxide conversion rate, the calorific value of 45 MJ / m 3 It has been shown that the above fuel gas mainly composed of methane and containing C2-C4 hydrocarbons can be obtained.

[0013] However, in order to ensure sufficient economic viability as a carbon-neutral city gas production process, there is a need for a catalyst that exhibits a high conversion rate to hydrocarbons at lower temperatures and can be easily prepared using inexpensive constituent materials. [Prior art documents] [Patent Documents]

[0014] [Patent Document 1] Japanese Patent Application Publication No. 59-46133 [Patent Document 2] Japanese Patent Application Publication No. 63-241099 [Patent Document 3] Japanese Patent Publication No. 2010-149109 [Overview of the project] [Problems that the invention aims to solve]

[0015] The problem that the present invention aims to solve, in view of the above problems, is to provide a catalyst for producing high-calorific value fuel gas that uses an inexpensive metal and produces a fuel gas mainly composed of methane, and also containing ethane, propane, and butane, from a mixed gas containing at least one of carbon monoxide or carbon dioxide and hydrogen at a relatively low temperature, with a high conversion rate, and to provide an energy-saving and highly efficient method for producing high-calorific value fuel gas using such a catalyst. [Means for solving the problem]

[0016] The characteristic configuration of the catalyst for producing high calorific value fuel gas according to the present invention is that it contains cobalt supported on an inorganic oxide carrier mainly composed of activated alumina, and lanthanum or manganese, wherein the amount of cobalt supported is 5.0 parts by mass or more and 20 parts by mass or less per 100 parts by mass of the inorganic oxide carrier, if lanthanum is supported, the amount of lanthanum supported is 1.0 part by mass or more and 10 parts by mass or less per 100 parts by mass of the inorganic oxide carrier, and if manganese is supported, the amount of manganese supported is 1.0 part by mass or more and 10 parts by mass or less per 100 parts by mass of the inorganic oxide carrier.

[0017] This characteristic configuration allows for the production of fuel gas from a mixed gas containing at least one of carbon monoxide or carbon dioxide and hydrogen, without using expensive constituent materials such as precious metals like platinum and ruthenium. This enables the production of fuel gas with a high conversion rate to hydrocarbons and a high calorific value, even at relatively low temperatures.

[0018] A further characteristic feature of the catalyst for producing high-calorific value fuel gas according to the present invention is that it contains 1.0 part by mass to 3.0 parts by mass of rhenium per 100 parts by mass of the inorganic oxide carrier.

[0019] In the catalyst for producing high-calorific value fuel gas of the present invention, rhenium functions as a co-catalyst, allowing the reduction reactions of carbon monoxide and carbon dioxide to proceed sufficiently.

[0020] A further characteristic feature of the catalyst for producing high-calorific value fuel gas according to the present invention is that the inorganic oxide support is a molded body with a particle size of 1.0 mm or more and 20 mm or less.

[0021] According to this characteristic configuration, the catalyst for producing high-calorific value fuel gas is highly active and has sufficient strength for industrial use, thus enabling the production of high-calorific value fuel gas using carbon monoxide and carbon dioxide as raw materials in an economically advantageous manner.

[0022] The characteristic configuration of the method for producing a catalyst for producing a high calorific value fuel gas according to the present invention is a method for producing a catalyst for producing a high calorific value fuel gas containing cobalt and lanthanum or manganese supported on an inorganic oxide carrier mainly composed of activated alumina, comprising: an impregnation step of impregnating the inorganic oxide carrier with an aqueous solution in which a water-soluble compound of cobalt and lanthanum or manganese is dissolved to obtain an impregnated body; a drying step of drying the impregnated body to obtain a dried body; and a calcination step of calcining the dried body at 350°C to 500°C.

[0023] The characteristic configuration of the method for producing a catalyst for producing high calorific value fuel gas according to the present invention is a method for producing a catalyst for producing high calorific value fuel gas containing cobalt, rhenium, and lanthanum or manganese supported on an inorganic oxide carrier mainly composed of activated alumina, comprising: an impregnation step of impregnating the inorganic oxide carrier with an aqueous solution in which a water-soluble compound of cobalt, rhenium, and lanthanum or manganese is dissolved to obtain an impregnated body; a drying step of drying the impregnated body to obtain a dried body; and a calcination step of calcining the dried body at 350°C to 500°C.

[0024] This characteristic configuration makes it possible to manufacture a catalyst for producing high-calorific value fuel gas that has a high conversion rate to hydrocarbons and can produce fuel gas with a high calorific value, even at relatively low temperatures, using relatively inexpensive constituent materials.

[0025] The characteristic configuration of the method for producing high-calorific value fuel gas according to the present invention is that a mixed gas containing at least one of carbon monoxide or carbon dioxide and hydrogen is brought into contact with a catalyst consisting of activated alumina supported with cobalt and lanthanum or manganese at a temperature of 225°C to 325°C to obtain a gas mainly composed of methane, and also containing ethane, propane, and butane.

[0026] The characteristic configuration of the method for producing high-calorific value fuel gas according to the present invention is that a mixed gas containing at least one of carbon monoxide or carbon dioxide and hydrogen is brought into contact with a catalyst consisting of activated alumina supported with cobalt, rhenium, and lanthanum or manganese at a temperature of 225°C to 325°C to obtain a gas mainly composed of methane, and also containing ethane, propane, and butane.

[0027] According to this characteristic configuration, a catalyst using relatively inexpensive constituent materials can produce a fuel gas with a high conversion rate and high calorific value from a mixed gas containing at least one of carbon monoxide or carbon dioxide and hydrogen, even at low temperatures. This makes it economically advantageous to produce high calorific value fuel gases. [Brief explanation of the drawing]

[0028] [Figure 1] This is a block flow diagram of the method for producing a carbon dioxide methane catalyst. [Modes for carrying out the invention]

[0029] The following describes embodiments of the catalyst for producing high-calorific value fuel gas, the method for producing the same, and the method for producing high-calorific value fuel gas according to the present invention.

[0030] The main component of the catalyst for producing high calorific value fuel gas of the present invention is activated alumina, more preferably transition alumina represented by γ-type and κ-type. Activated alumina undergoes a phase transition to α-type by methods such as calcination at a high temperature of 1100°C or higher. However, α-type alumina has a small specific surface area and cannot support the active metal in a highly dispersed manner, making it unsuitable as a support for the catalyst molded body of the present invention. In the catalyst for producing high calorific value fuel gas of the present invention, it is preferable that the activated alumina does not contain α-type alumina, or if it does, that its mass ratio to the total alumina is 30% or less, and more preferably 5% or less.

[0031] Furthermore, the activated alumina molded bodies used in this invention are not limited in size or shape, but are usually molded into spherical or cylindrical shapes with a diameter of 1 mm to 20 mm. In this invention, however, a diameter of 3 mm to 5 mm is preferable. Such molded bodies can be obtained by rolling granulation or tableting.

[0032] The catalyst for producing high-calorific value fuel gas of the present invention is a molded body with a particle size of 1 to 20 mm, although its shape is not limited. Here, a particle size of 1 to 20 mm means that if the molded body is spherical, its diameter is in the range of 1 to 20 mm; if the molded body is cylindrical, its diameter and length are in the range of 1 to 20 mm; and if it is of any other shape, its hydrodynamic equivalent diameter is in the range of 1 to 20 mm.

[0033] If the particle size of the molded body is smaller than 1 mm, the pressure loss when the reaction gas is passed through the reaction vessel filled with the catalyst molded body will increase, potentially worsening the economic efficiency of the high-calorific value fuel gas production process. On the other hand, if the particle size is larger than 20 mm, the geometric surface area of ​​the molded body will be relatively small, which may reduce the catalytic activity.

[0034] The catalyst for producing high-calorific value fuel gas of the present invention comprises cobalt supported on activated alumina and lanthanum or manganese.

[0035] In the catalyst for producing high-calorific value fuel gas of the present invention, cobalt acts as the main active metal responsible for the function of hydrocarbon synthesis through the hydrogenation reaction of carbon monoxide and carbon dioxide.

[0036] If the amount of cobalt supported is less than 5.0 parts by mass per 100 parts by mass of activated alumina molded body, sufficient catalytic activity cannot be obtained, resulting in a low conversion rate of carbon monoxide or carbon dioxide. The resulting gas will contain large amounts of carbon monoxide, carbon dioxide, and hydrogen, and the cost of separating them will be high, potentially reducing the economic viability of fuel gas production. Conversely, if the amount of cobalt is greater than 20 parts by mass per 100 parts by mass of activated alumina molded body, the methane activity for carbon dioxide commensurate with the supported amount cannot be obtained, leading to a decrease in economic viability.

[0037] In the catalyst for producing high-calorific value fuel gas of the present invention, lanthanum and manganese promote the growth of carbon chains on the catalyst surface and act as co-catalysts to enhance the function of high-calorific value hydrocarbon synthesis.

[0038] If the amount of lanthanum and manganese supported is less than 1.0 part by mass per 100 parts by mass of the activated alumina molded body, the co-catalyst function will not be sufficiently obtained, and the majority of the generated gas composition will be methane, resulting in a gas with low calorific value and potentially failing to achieve the full effect of the addition. Conversely, if the amount of lanthanum and manganese supported is greater than 10 parts by mass per 100 parts by mass of the activated alumina molded body, the effect will not be commensurate with the amount supported, potentially leading to an economic disadvantage.

[0039] In the catalyst for producing high calorific value fuel gas of the present invention, rhenium functions as a promoter and contributes to improving the reducibility of cobalt. When the supported amount of rhenium is less than 1.0 part by mass with respect to 100 parts by mass of the activated alumina molded body, cobalt exists in the catalyst as an oxide, and the reduction reactions of carbon monoxide and carbon dioxide do not proceed sufficiently. On the other hand, the effect of rhenium as a promoter can be sufficiently obtained if the supported amount thereof is 1.0 part by mass or more with respect to 100 parts by mass of the activated alumina molded body. On the other hand, when the supported amount of rhenium is more than 3.0 parts by mass with respect to 100 parts by mass of the activated alumina molded body, an effect commensurate with the supported amount cannot be obtained, and there is a risk of being economically disadvantageous.

[0040] Also, when the total supported amount of cobalt, rhenium, lanthanum and manganese is more than 25 parts by mass with respect to 100 parts by mass of the activated alumina molded body, the dispersibility of the supported cobalt, rhenium, lanthanum and manganese becomes low, and in addition, the gas diffusibility in the activated alumina support decreases, and there is a possibility that the activity commensurate with the supported amount cannot be obtained. From the above viewpoints, the supported amount of cobalt is 5.0 parts by mass or more and 20 parts by mass or less, more preferably 10 parts by mass or more and 15 parts by mass or less, with respect to 100 parts by mass of the activated alumina molded body, the supported amount of rhenium is 1.0 to 3.0 parts by mass, when lanthanum is supported, the supported amount of lanthanum is 1.0 part by mass or more and 10.0 parts by mass or less, more preferably 3.0 parts by mass or more and 10.0 parts by mass or less, still more preferably 5.0 parts by mass or more and 10.0 parts by mass or less, with respect to 100 parts by mass of the activated alumina molded body, and when manganese is supported, the supported amount of manganese is preferably 1.0 part by mass or more and 10.0 parts by mass or less with respect to 100 parts by mass of the activated alumina molded body.

[0041] The BET specific surface area of the methanation catalyst of the present invention is usually in the range of 50 m 2 / g to 200 m 2 / g, and it is preferable that it is 50 m 2 / g to 80 m 2 / g because the low-temperature activity is improved, and 65 m 2 / g to 80 m 2A concentration of / g is preferable because it further improves low-temperature activity. When the catalyst is prepared using activated alumina calcined in air at 800°C to 1050°C, the BET specific surface area is 50 m². 2 / g~80m 2 A methanation catalyst of / g is easily obtained.

[0042] <Method for manufacturing catalysts for high-calorific value fuel gas production> The present invention provides a method for producing a catalyst for high calorific value fuel gas, comprising: an impregnation step S100 in which an inorganic oxide support mainly composed of activated alumina is impregnated with an aqueous solution in which a water-soluble compound of cobalt and lanthanum or manganese is dissolved to obtain an impregnated body; a drying step S101 in which the impregnated body is dried to obtain a dried body; and a calcination step S102 in which the dried body is calcined at 350°C to 500°C to obtain a support on which cobalt and lanthanum or manganese are dispersed and supported. A block flow diagram of the present invention provides a method for producing a catalyst for high calorific value fuel gas, as shown in Figure 1.

[0043] <Impregnation process> First, an impregnation step S100 is performed in which an inorganic oxide support, mainly composed of activated alumina, is impregnated with an aqueous solution containing a water-soluble compound of cobalt and lanthanum or manganese to obtain an impregnated body. As a result, an impregnated body is obtained, which consists of an inorganic oxide support containing cobalt and lanthanum or manganese. Cobalt and lanthanum or manganese can be simultaneously impregnated into an inorganic oxide support mainly composed of activated alumina using an aqueous solution that dissolves both a water-soluble cobalt compound and a water-soluble lanthanum or manganese compound. The impregnation process S100 can be carried out in multiple steps as needed, but in the catalyst for producing high-heat fuel gas of the present invention, the required amount of cobalt and lanthanum or manganese can usually be supported in a single impregnation process.

[0044] There are no particular restrictions on the amount of cobalt contained in the aqueous solution, but it is preferable that the amount of cobalt contained in the aqueous solution be 5.0 parts by mass or more and 20 parts by mass or less per 100 parts by mass of the inorganic oxide support mainly composed of activated alumina, and more preferably 10 parts by mass or more and 15 parts by mass or less per 100 parts by mass of the inorganic oxide support. If the amount of cobalt contained in the aqueous solution is less than 5.0 parts by mass per 100 parts by mass of the inorganic oxide support, the methane activity of carbon dioxide will be low, and in order to carry out the methane reaction, it will be necessary to use a large amount of catalyst for the production of high-heat fuel gas or to raise the reaction temperature, which will reduce economic efficiency. If the amount of cobalt contained in the aqueous solution is greater than 20 parts by mass per 100 parts by mass of the support, the methane activity of carbon dioxide commensurate with the amount supported will not be obtained, which will reduce economic efficiency.

[0045] There are no particular restrictions on the amount of lanthanum contained in the aqueous solution, but it is preferable that the amount of lanthanum contained in the aqueous solution be between 1.0 part by mass and 10 parts by mass per 100 parts by mass of the inorganic oxide support mainly composed of activated alumina. If the amount of lanthanum contained in the aqueous solution is less than 1.0 part by mass per 100 parts by mass of the support, the function as a co-catalyst cannot be sufficiently obtained, and the majority of the generated gas composition will be methane, resulting in a gas with low calorific value that cannot be obtained, and thus the effect of the addition may not be sufficiently obtained. On the other hand, if the amount of lanthanum supported is greater than 10 parts by mass per 100 parts by mass of the activated alumina molded body, the effect commensurate with the amount supported may not be obtained, which may be economically disadvantageous.

[0046] There are no particular restrictions on the amount of manganese contained in the aqueous solution, but it is preferable that the amount of manganese in the aqueous solution be between 1.0 part by mass and 10 parts by mass per 100 parts by mass of the inorganic oxide support mainly composed of activated alumina. If the amount of manganese contained in the aqueous solution is less than 1.0 part by mass per 100 parts by mass of the support, the function as a co-catalyst cannot be sufficiently obtained, and the majority of the generated gas composition will be methane, resulting in a gas with low calorific value that cannot be obtained, and thus the effect of the addition may not be sufficiently obtained. On the other hand, if the amount of manganese supported is greater than 10 parts by mass per 100 parts by mass of the activated alumina molded body, the effect commensurate with the amount supported may not be obtained, which may be economically disadvantageous.

[0047] When the impregnation process is carried out in multiple stages, there is no particular need to change the concentration ratio of cobalt to lanthanum or manganese, but the concentration ratio of cobalt to lanthanum or manganese may be changed between the first and second loading stages if necessary.

[0048] Examples of water-soluble cobalt compounds that can be used include cobalt nitrate (Co(NO3)2) and cobalt acetate (Co(CH3COO)2).

[0049] As a water-soluble compound of lanthanum, for example, lanthanum nitrate (La(NO3)3) can be used.

[0050] Manganese nitrate (Mn(NO3)2) can be used as a water-soluble compound of manganese.

[0051] There are no particular restrictions on the temperature or duration of the cobalt-lanthanum-manganese impregnation process, but it can be carried out at room temperature for approximately 1 to 20 hours.

[0052] <Drying process> A drying step S101 is performed to dry the impregnated body containing cobalt and lanthanum or manganese obtained in the impregnation step S100. As a result, a dried body is obtained that contains cobalt and lanthanum or manganese and is composed of an inorganic oxide support mainly composed of activated alumina. There are no particular restrictions on the drying method performed in the drying step S101, but it can be done by removing the impregnated body from the water-soluble compound of cobalt and lanthanum or manganese, or by placing the impregnated body in a dryer with an aqueous solution of the water-soluble compound of cobalt and lanthanum or manganese and drying it at a predetermined temperature for a predetermined time, or by heating the impregnated body with an aqueous solution of the water-soluble compound of cobalt and lanthanum or manganese and evaporating it to dryness. There are no particular restrictions on the temperature or time of the drying step S101, but for example, it can be performed at 80°C to 200°C for about 1 to 20 hours.

[0053] <Firing Process> Finally, a firing step S102 is performed in which the dried material obtained in the drying step S101 is fired at a predetermined temperature for a predetermined time. As a result, a catalyst for producing high-heat fuel gas is obtained, which consists of cobalt and lanthanum or manganese dispersed and supported on a carrier mainly composed of activated alumina. There are no particular restrictions on the firing method performed in the firing step S102, but it can be done by placing the dried material obtained in the drying step S101 into an electric furnace and firing it.

[0054] If the firing temperature is too low, the decomposition of cobalt, lanthanum, or manganese compounds may be insufficient. If it is too high, the sintering of activated alumina may proceed, reducing its specific surface area. Therefore, it is best to set the temperature between 350°C and 500°C.

[0055] The firing process time should preferably be between 1 hour and 20 hours, as too short a time may result in insufficient decomposition of cobalt, lanthanum, or manganese compounds, while too long a time may be economically disadvantageous and may reduce the specific surface area of ​​activated alumina.

[0056] Air is acceptable as the gas used in the firing process, but oxygen or nitrogen may be added as needed to adjust the oxygen concentration.

[0057] In the impregnation process described above, an aqueous solution containing a water-soluble compound of rhenium, in addition to a water-soluble compound of cobalt and lanthanum or manganese, is impregnated into an inorganic oxide support mainly composed of activated alumina. After the completion of the drying and calcination processes, a catalyst for producing high-heat fuel gas can be obtained, in which cobalt, rhenium, and lanthanum or manganese are dispersed and supported.

[0058] Examples of water-soluble rhenium compounds that can be used include perrhenic acid (HReO4) and ammonium perrhenate (NH4ReO4).

[0059] When rhenium is supported on an inorganic oxide support, it is preferable that the amount of rhenium in the aqueous solution is between 1.0 part by mass and 3.0 parts by mass per 100 parts by mass of the inorganic oxide support. If the amount of rhenium supported is less than 1.0 part by mass per 100 parts by mass of the inorganic oxide support, the reduction reactions of carbon monoxide and carbon dioxide will not proceed sufficiently due to the presence of cobalt as an oxide in the catalyst. If the amount of rhenium supported is greater than 3.0 parts by mass per 100 parts by mass of the inorganic oxide support, the effect commensurate with the amount supported may not be obtained, which may be economically disadvantageous.

[0060] When the impregnation process is carried out in multiple stages, there is no particular need to change the concentration ratio of cobalt, rhenium, and lanthanum or manganese. However, if necessary, the concentration ratio of cobalt, rhenium, and lanthanum or manganese may be changed between the first, second, and third loading stages.

[0061] Furthermore, there are no particular restrictions on the temperature or duration of the cobalt-rhenium-lanthanum-manganese impregnation process, but it can be carried out, for example, at room temperature for about 1 to 20 hours.

[0062] In a catalyst for producing high-heat fuel gas obtained through the above impregnation, drying, and calcination processes, cobalt, rhenium, and lanthanum or manganese are dispersed and supported on the catalyst. The cobalt and rhenium are uniformly supported on the catalyst and are in close proximity to each other. As a result, the rhenium enhances the reducing properties of the cobalt, and the cobalt functions effectively as an active site for the hydrogenation reaction of carbon monoxide or carbon dioxide.

[0063] <Method for producing high-calorific fuel gas using carbon monoxide or carbon dioxide as a raw material> The method for producing high-heat fuel gas according to the present invention is carried out by passing a mixed gas containing at least one of carbon monoxide or carbon dioxide and hydrogen through a reactor on which the catalyst for producing high-heat fuel gas according to the present invention is placed.

[0064] The carbon monoxide, carbon dioxide, and hydrogen used in the mixed gas can be produced by any method, as long as they have sufficient purity and properties to be used in the production of high-heat fuel gas in the presence of a catalyst for high-heat fuel gas production.

[0065] Hydrogen may be, for example, electrolyzed hydrogen obtained by electrolyzing water. Carbon monoxide and carbon dioxide may be recovered from combustion exhaust gas by known carbon oxide recovery methods such as the amine absorption method, or they may be contained in biogas obtained by methane fermentation of organic matter. Biogas is usually obtained as a mixed gas of methane and carbon dioxide, but carbon dioxide may be separated from this mixed gas and used in the methanation reaction, or it may be used to produce high-heat fuel gas without separating the methane.

[0066] If carbon monoxide, carbon dioxide, and hydrogen contain sulfur, halogen compounds, siloxane compounds, heavy hydrocarbons, etc., these can cause degradation of the catalyst for producing high-heat fuel gases. Therefore, it is preferable to remove these components as needed before using them to produce high-heat fuel gases.

[0067] In the production of high-calorific value fuel gases, the ratio of carbon monoxide or carbon dioxide to hydrogen in a mixed gas containing at least one of carbon monoxide or carbon dioxide and hydrogen should be 2.5 to 3 in the hydrogen / carbon monoxide molar ratio if only carbon monoxide is present as a carbon oxide, approximately 3.5 to 4 in the hydrogen / carbon monoxide molar ratio if only carbon dioxide is present as a carbon oxide, and appropriately selected within the range of 2.5 to 4 in the hydrogen / (carbon monoxide + carbon dioxide) molar ratio depending on the proportion of carbon monoxide and carbon dioxide present. If the hydrogen / carbon monoxide (or carbon dioxide) molar ratio is higher than the above, a large amount of hydrogen will remain in the produced fuel gas, which may be economically disadvantageous, and the calorific value of the fuel gas may decrease because C2-C4 hydrocarbons will not be easily generated. On the other hand, if the hydrogen / carbon monoxide (or carbon dioxide) molar ratio is lower than the above, a large amount of carbon monoxide and carbon dioxide will remain in the produced fuel gas, which may be economically disadvantageous.

[0068] The catalyst for producing high-calorific value fuel gas of the present invention exhibits high activity in hydrocarbon synthesis from carbon monoxide and carbon dioxide, but its activity is insufficient at temperatures below 225°C. Furthermore, at temperatures above 325°C, the rate of methane production becomes extremely fast compared to the production of C2-C4 hydrocarbons, which may increase the proportion of methane in the fuel gas and reduce its calorific value.

[0069] Therefore, the temperature at which a mixed gas containing at least one of carbon monoxide or carbon dioxide and hydrogen is brought into contact with a catalyst for producing high-calorific value fuel gases shall be between 225°C and 325°C.

[0070] The reaction of carbon monoxide and carbon dioxide with hydrogen to produce hydrocarbons generates a relatively large amount of heat, so if the reaction is carried out adiabatically, the temperature of the catalyst layer may rise to around 200°C to 400°C. When the temperature of the catalyst layer rises, the supported cobalt, rhenium, lanthanum, or manganese aggregates, reducing the catalytic activity. Furthermore, there is a concern that the activated alumina may sinter and undergo a phase change, reducing the strength of the catalyst. In addition, the decomposition of the generated C2-C4 hydrocarbons on the catalyst may reduce the calorific value of the fuel gas.

[0071] The method for producing high-calorific value fuel gas according to the present invention is preferably carried out using a heat exchange reactor to remove reaction heat while maintaining the catalyst temperature in the range of 225°C to 325°C. It is preferable that the entire catalyst layer be maintained in the range of 225°C to 325°C, but it is not a major problem if a part of the catalyst layer falls outside this range. However, if the catalyst layer temperature falls below 225°C, it does not contribute to the progress of the reaction, which may be economically disadvantageous, and if the catalyst layer temperature falls significantly above 325°C, the decomposition of the C2-C4 hydrocarbons may proceed.

[0072] The shape of the heat exchange reactor may be either a shell-and-tube type or a plate-type reactor, and if a shell-and-tube type is used, the catalyst may be packed into either the shell side or the tube side.

[0073] In the method for producing high-calorific value fuel gas of the present invention, a portion of the reactor outlet gas may be recycled to the reactor inlet, the gas obtained after condensing and separating hydrocarbons having 5 or more carbon atoms from the generated fuel gas may be recycled to the reactor inlet, or hydrogen and / or carbon dioxide may be separated from the generated fuel gas by membrane separation and recycled to the reactor inlet. The reaction pressure in the method for producing high-calorific value fuel gas of the present invention is not particularly restricted, but it is carried out under a pressure of atmospheric pressure to 5 MPa. [Examples]

[0074] The present invention will be described more specifically below based on examples and comparative examples, but the present invention is not limited to the following examples.

[0075] (Example 1) 29.6 g of cobalt nitrate hexahydrate (Co(NO3)2·6H2O) and 6.23 g of lanthanum nitrate hexahydrate (La(NO3)3·6H2O) were dissolved in pure water to obtain aqueous solutions that dissolve the cobalt compound and the lanthanum compound. Activated alumina (Sumitomo Chemical, KHA-24, 2.0-4.0 mm spherical molded body, BET specific surface area 162 m²) was used. 2 40.0 g of the material was immersed in the aforementioned aqueous solution for 1.0 hour to impregnate it, then evaporated to dryness on a hot plate, and dried in a drying oven maintained at 110°C for 3.0 hours to obtain a dried body. This dried body was loaded into an electric furnace and heated from room temperature to 360°C over 3.0 hours while air was passed through it, and then fired at 360°C for 6 hours. After that, it was allowed to cool to room temperature over 3.0 hours to obtain catalyst A, in which 15 parts by mass of cobalt and 5.0 parts by mass of lanthanum were supported per 100 parts by mass of activated alumina. The BET specific surface area of ​​catalyst A was 122 m². 2 It was / g.

[0076] (Example 2) 29.6 g of cobalt nitrate hexahydrate (Co(NO3)2·6H2O), 6.23 g of lanthanum nitrate hexahydrate (La(NO3)3·6H2O), and 1.73 g of ammonium perrhenate (NH4ReO4) were dissolved in pure water to obtain an aqueous solution that dissolves the cobalt compound, the lanthanum compound, and the rhenium compound. Activated alumina (Sumitomo Chemical, KHA-24, 2.0-4.0 mm spherical molded body, BET specific surface area 162 m²) was used. 240.0 g of the material was immersed in the aforementioned aqueous solution for 1.0 hour to impregnate it, then evaporated to dryness on a hot plate, and dried in a drying oven maintained at 110°C for 3.0 hours to obtain a dried body. This dried body was loaded into an electric furnace and heated from room temperature to 360°C over 3.0 hours while air was passed through it, and then fired at 360°C for 6.0 hours. After that, it was allowed to cool to room temperature over 3.0 hours to obtain catalyst B, which supported 15 parts by mass of cobalt, 5.0 parts by mass of lanthanum, and 3.0 parts by mass of rhenium per 100 parts by mass of activated alumina. The BET specific surface area of ​​catalyst B was 125 m². 2 It was / g.

[0077] (Example 3) 29.6 g of cobalt nitrate hexahydrate (Co(NO3)2·6H2O), 12.5 g of lanthanum nitrate hexahydrate (La(NO3)3·6H2O), and 1.73 g of ammonium perrhenate (NH4ReO4) were dissolved in pure water to obtain an aqueous solution that dissolves the cobalt compound, the lanthanum compound, and the rhenium compound. Activated alumina (Sumitomo Chemical, KHA-24, 2.0-4.0 mm spherical molded body, BET specific surface area 162 m²) was used. 2 40.0 g of the material was immersed in the aforementioned aqueous solution for 1.0 hour to impregnate it, then evaporated to dryness on a hot plate, and dried in a drying oven maintained at 110°C for 1.0 hour to obtain a dried body. This dried body was loaded into an electric furnace and heated from room temperature to 360°C over 3.0 hours while air was passed through it, and then fired at 360°C for 6.0 hours. After that, it was allowed to cool to room temperature over 3.0 hours to obtain catalyst C, which supported 15 parts by mass of cobalt, 10 parts by mass of lanthanum, and 3.0 parts by mass of rhenium per 100 parts by mass of activated alumina. The BET specific surface area of ​​catalyst C was 118 m². 2 It was / g.

[0078] (Example 4) 19.8 g of cobalt nitrate hexahydrate (Co(NO3)2·6H2O), 12.5 g of manganese nitrate hexahydrate (Mn(NO3)2·6H2O), and 1.15 g of ammonium perrhenate (NH4ReO4) were dissolved in pure water to obtain an aqueous solution that dissolves the cobalt, manganese, and rhenium compounds. Activated alumina (Sumitomo Chemical, KHA-24, 2.0-4.0 mm spherical molded body, BET specific surface area 162 m²) was also used. 2 40.0 g of the material was immersed in the aforementioned aqueous solution for 1.0 hour to impregnate it, then evaporated to dryness on a hot plate, and dried in a drying oven maintained at 110°C for 3.0 hours to obtain a dried body. This dried body was loaded into an electric furnace and, while passing air through it, the temperature was raised from room temperature to 360°C over 3.0 hours, and then held at 360°C for 6.0 hours to calcinate it. After that, it was allowed to cool to room temperature over 3.0 hours to obtain catalyst D, which supported 10 parts by mass of cobalt, 6.0 parts by mass of manganese, and 2.0 parts by mass of rhenium per 100 parts by mass of activated alumina. The BET specific surface area of ​​catalyst D was 125 m². 2 It was / g.

[0079] (Comparative Example 1) 19.8 g of cobalt nitrate hexahydrate (Co(NO3)2·6H2O) was dissolved in pure water to obtain an aqueous solution that dissolves cobalt compounds. Activated alumina (Sumitomo Chemical, KHA-24, 2.0-4.0 mm spherical molded body, BET specific surface area 162 m²) was used. 2 40.0 g of the material was immersed in the aforementioned aqueous solution for 1.0 hour to impregnate it, then evaporated to dryness on a hot plate, and dried in a drying oven maintained at 110°C for 3.0 hours to obtain a dried body. This dried body was loaded into an electric furnace and heated from room temperature to 360°C over 3.0 hours while air was passed through it, and then fired at 360°C for 6 hours. After that, it was allowed to cool to room temperature over 3 hours to obtain catalyst E, in which 10 parts by mass of cobalt were supported per 100 parts by mass of activated alumina. The BET specific surface area of ​​catalyst E was 146 m². 2 It was / g.

[0080] (Comparative Example 2) 19.8 g of cobalt nitrate hexahydrate (Co(NO3)2·6H2O) and 1.15 g of ammonium perrhenate (NH4ReO4) were dissolved in pure water to obtain an aqueous solution that dissolves both the cobalt compound and the rhenium compound. Activated alumina (Sumitomo Chemical, KHA-24, 2.0-4.0 mm spherical molded body, BET specific surface area 162 m²) was used. 2 40.0 g of the material was immersed in the aforementioned aqueous solution for 1.0 hour to impregnate it, then evaporated to dryness on a hot plate, and dried in a drying oven maintained at 110°C for 1.0 hour to obtain a dried body. This dried body was loaded into an electric furnace and heated from room temperature to 360°C over 3.0 hours while air was passed through it, and then fired at 360°C for 6.0 hours. After that, it was allowed to cool to room temperature over 3.0 hours to obtain catalyst F, which had 15 parts by mass of cobalt and 2.0 parts by mass of rhenium supported on 100 parts by mass of activated alumina. The BET specific surface area of ​​catalyst F was 143 m². 2 It was / g.

[0081] (Catalyst analysis results) The BET specific surface area was measured for each of the catalysts A, B, C, D, E, and F. The results are shown in Table 1.

[0082] [Table 1]

[0083] 《Method for measuring BET specific surface area》 For each sample before and after high-temperature firing, the BET specific surface area was measured using the BET single-point method, which utilizes the amount of nitrogen adsorbed under the condition of relative pressure (P / P0) = 0.3 at liquid nitrogen temperature.

[0084] (Evaluation results of hydrocarbon synthesis activity) The hydrocarbon synthesis activity of each catalyst, A, B, C, D, E, and F, was evaluated. The results are shown in Table 2.

[0085] [Table 2]

[0086] Methods for evaluating hydrocarbon synthesis activity A catalyst layer was formed by filling a stainless steel reaction tube (16 mm inner diameter) with 5 mL of catalyst. While heating the catalyst layer to maintain its temperature at 400°C, a reducing gas (a mixture of nitrogen gas and 10% hydrogen gas by volume) was circulated at a rate of 12.0 liters per hour (volume at standard conditions of 0°C and 101.325 kPa; the same applies below) for 1 hour of reduction treatment. After the reduction treatment described above, the catalyst layer temperature was changed to 200°C, and a gas with a volume ratio of carbon monoxide:carbon dioxide:hydrogen:nitrogen = 9.4:3.1:40.6:46.9 was flowed through the catalyst layer at a flow rate of 20 liters per hour. The concentrations of carbon monoxide, carbon dioxide, hydrogen, nitrogen, and hydrocarbons with 1 to 6 carbon atoms (methane to hexane) in the catalyst layer outlet gas were analyzed using a gas chromatograph (Shimadzu GC-2014B, with TCD and FID detectors). Subsequently, while the test gas was still flowing, the catalyst layer temperature was sequentially changed in 25°C increments up to 325°C, and the catalyst layer outlet gas was similarly analyzed using a gas chromatograph. The reaction pressure was set to 0.7 MPa (absolute pressure). Note that nitrogen is not essential for carrying out this reaction; it was added to mitigate the temperature rise and facilitate control of the catalyst layer temperature. Based on the analysis results of the catalyst layer outlet gas, the hydrocarbon yield, C1-C4 hydrocarbon yield, and calorific value (C1-C4 hydrocarbon calorific value) were calculated using the following formula. The C1-C4 hydrocarbon yield represents the proportion of carbon monoxide and carbon dioxide supplied to the catalyst layer that were converted to C1-C4 hydrocarbons. The C1-C4 hydrocarbon calorific value was calculated assuming that hydrocarbons above C5 are separated by condensation from the generated gas, and hydrogen, carbon monoxide, and carbon dioxide are separated by methods such as membrane separation, and that the calorific value of the C1-C4 hydrocarbon components that can be used as a raw material for city gas was calculated. In addition, C2-C4 hydrocarbons may contain very small amounts of unsaturated hydrocarbons (such as ethylene), but these can be easily converted to saturated hydrocarbons (such as ethane) by passing them through a hydrogenation catalyst and hydrogenating them with unreacted hydrogen as needed. Therefore, the calorific value of unsaturated hydrocarbons (e.g., ethylene) was calculated using the calorific value of the corresponding saturated hydrocarbon (e.g., ethane) using the following formula.

[0087] Hydrocarbon yield (%) = (Carbon content of hydrocarbons in the catalyst outlet gas) / (Carbon content of all gases in the catalyst outlet gas) C1-C4 hydrocarbon yield (%) = (carbon content of C1-C4 hydrocarbons in the catalyst outlet gas) / (carbon content of all gases in the catalyst outlet gas) C1~C4 hydrocarbon calorific value (MJ / Nm 3 ) = (39.8m + 69.7e + 99.1p + 128.5b) / (m + e + p + b) where m, e, p, and b are the volume-based content of methane, ethane, propane, and butane in the catalyst layer outlet gas, respectively.

[0088] Evaluation of the Examples and Comparative Examples In Catalyst A of Example 1, the C1-C4 hydrocarbon yield was 12.8% at a catalyst layer temperature of 225°C, but increased to 68.3% at 250°C, 67.4% at 275°C, and 42.9% at 300°C. The C1-C4 hydrocarbon calorific value was 57.1 MJ / Nm³ at a catalyst layer temperature of 225°C. 3 , 46.2 MJ / Nm at 250℃ 3 46.0 MJ / Nm at 275℃ 3 51.9 MJ / Nm at 300℃ 3The results were as follows: When catalyst A from Example 1 is used to react carbon monoxide, carbon dioxide, and hydrogen at 250°C to 275°C, C1-C4 hydrocarbons are obtained in a yield of 50% or more, and the calorific value is 45 MJ / Nm³. 3 It is clear that a high-calorific value fuel gas, more suitable for use as city gas, can be obtained. In Catalyst B of Example 2, the C1-C4 hydrocarbon yield was 84.1% at a catalyst layer temperature of 225°C, but increased to 87.4% at 250°C, 88.2% at 275°C, and 88.6% at 300°C. The calorific value of C1-C4 hydrocarbons was 41.1 MJ / Nm³ at a catalyst layer temperature of 225°C. 3 , 40.5 MJ / Nm at 250℃ 3 , 40.5 MJ / Nm at 275℃ 3 40.7 MJ / Nm at 300℃ 3 The results were as follows. From these results, when catalyst B of Example 2 was used to react carbon monoxide, carbon dioxide, and hydrogen at 225°C to 300°C, the amount of hydrocarbon heat for C1-C4 decreased compared to when catalyst A of Example 1 was used, while the hydrocarbon yield for C1-C4 improved compared to Example 1. This trend is presumed to be due to the addition of rhenium, which promoted the reduction of cobalt and improved the hydrogenation activity of the catalyst, thereby improving the methane yield. In Catalyst C of Example 3, the C1-C4 hydrocarbon yield was 79.7% at a catalyst layer temperature of 225°C, but increased to 81.9% at 250°C, 79.7% at 275°C, and 68.3% at 300°C. The C1-C4 hydrocarbon calorific value was 42.3 MJ / Nm³ at a catalyst layer temperature of 225°C. 3 , 41.7 MJ / Nm at 250℃ 3 , 43.6 MJ / Nm at 275℃ 3 48.3 MJ / Nm at 300℃ 3 The results were as follows: When catalyst C from Example 3, in which the amount of lanthanum supported was adjusted, was used to react carbon monoxide, carbon dioxide, and hydrogen at 225°C to 300°C, a relatively high C1-C4 hydrocarbon yield of 41.0 MJ / Nm³ was obtained compared to when catalyst A from Example 1 and catalyst B from Example 2 were used. 3 This makes it possible to synthesize gases with the above-mentioned high calorific value. In Catalyst D of Example 4, the C1-C4 hydrocarbon yield was 78.0% at a catalyst layer temperature of 225°C, but increased to 80.7% at 250°C, 80.7% at 275°C, and 75.1% at 300°C. The C1-C4 hydrocarbon calorific value was 41.9 MJ / Nm³ at a catalyst layer temperature of 225°C. 3 , 41.3 MJ / Nm at 250℃ 3 , 41.6 MJ / Nm at 275℃ 3 42.4 MJ / Nm at 300℃ 3 The results were as follows. From these results, it was found that when catalyst D containing cobalt-rhenium-manganese, with manganese added as a supported component, is used to react carbon monoxide, carbon dioxide, and hydrogen at 225°C to 300°C, the hydrocarbon yield of C1-C4 is 75% or more, and the hydrocarbon heat of C1-C4 is 41 MJ / Nm³. 3 The gas can be synthesized. Compared to catalyst F in Comparative Example 2, the hydrocarbon calorific value of C1-C4 increased, suggesting that manganese support improved the carbon chain growth reaction on the catalyst surface, which may have increased the yields of ethane, propane, and butane.

[0089] From the above results, it is clear that when the catalyst for producing high-calorific value fuel gas of the present invention is used, a high-calorific value fuel gas consisting of C1-C4 hydrocarbons exhibiting a high calorific value and high yield can be obtained from a mixed gas containing at least one of carbon monoxide or carbon dioxide and hydrogen at a relatively low temperature of 225°C to 325°C.

[0090] <Evaluation of durability tests> Examples 2 and 3 (catalysts B and C) and Comparative Example 2 (catalyst F) were evaluated through a 24-hour endurance test.

[0091] 《Evaluation Method for Durability Tests》 A catalyst layer was formed by filling a stainless steel reaction tube (16 mm inner diameter) with 5 mL of catalyst. While heating the catalyst layer to maintain its temperature at 400°C, a gas (reducing gas) with a volume ratio of nitrogen:hydrogen = 9:1 was flowed through it at a rate of 20.0 liters per hour (volume at standard conditions of 0°C and 101.325 kPa; the same applies below) and the reduction treatment was carried out for 1 hour. After the reduction treatment described above, the temperature of the catalyst layer was changed to 225°C or 250°C (Examples 2 and 3: 250°C, Comparative Example 2: 225°C). Gas with a volume ratio of carbon monoxide:carbon dioxide:hydrogen:nitrogen = 9.4:3.1:40.6:46.9 was flowed into the catalyst layer at a flow rate of 20 liters per hour. The concentrations of carbon monoxide, carbon dioxide, hydrogen, nitrogen, and hydrocarbons with 1 to 6 carbon atoms (methane to hexane) in the catalyst layer outlet gas were analyzed every hour using a gas chromatograph (Shimadzu GC-2014B, with TCD and FID detectors). The reaction pressure was 0.7 MPa (absolute pressure). Note that nitrogen is not essential for carrying out this reaction, but was added to mitigate the temperature rise and facilitate control of the catalyst layer temperature.

[0092] Based on the analysis results of the catalyst layer outlet gas, the hydrocarbon yield, C1-C4 hydrocarbon yield, and calorific value (C1-C4 hydrocarbon calorific value) were calculated using the formula described above. The C1-C4 hydrocarbon yield represents the proportion of carbon monoxide and carbon dioxide supplied to the catalyst layer that were converted to C1-C4 hydrocarbons. The C1-C4 hydrocarbon calorific value was calculated assuming that hydrocarbons above C5 are separated by condensation from the generated gas, and hydrogen, carbon monoxide, and carbon dioxide are separated by methods such as membrane separation. This calculation represents the calorific value of the C1-C4 hydrocarbon components that can be used as raw materials for city gas. Although C2-C4 hydrocarbons may contain very small amounts of unsaturated hydrocarbons (such as ethylene), these can be easily converted to saturated hydrocarbons (such as ethane) by passing them through a hydrogenation catalyst and hydrogenating them with unreacted hydrogen as needed. Therefore, the calorific value of unsaturated hydrocarbons (e.g., ethylene) was used for calculations based on the calorific value of the corresponding saturated hydrocarbon (e.g., ethane).

[0093] For Examples 2 and 3 (catalysts B and C) and Comparative Example 2 (catalyst F), analysis was performed by gas chromatography for 1 to 24 hours as described above, and the hydrocarbon yield, C1-C4 hydrocarbon yield, and calorific value (C1-C4 hydrocarbon calorific value) were calculated. The results are shown in Table 3.

[0094] [Table 3]

[0095] • Example 2 (Catalyst B) As shown in Table 3, the hydrocarbon yield after 24 hours (79.9%) decreased by 6.8% compared to the hydrocarbon yield after 1 hour (86.7%), and the C1-C4 hydrocarbon yield after 24 hours (77.7%) decreased by 8.9% compared to the C1-C4 hydrocarbon yield after 1 hour (86.6%). The calorific value of C1-C4 hydrocarbons after 1 hour was 40.2 MJ / Nm³. 3 ) and the C1-C4 hydrocarbon heat output after 24 hours (43.1 MJ / Nm³) 3 ) is 2.9 MJ / Nm 3 It increased.

[0096] Example 3 (Catalyst C) As shown in Table 3, the hydrocarbon yield after 24 hours (74.9%) decreased by 8.0% compared to the hydrocarbon yield after 1 hour (82.9%), and the C1-C4 hydrocarbon yield after 24 hours (71.8%) decreased by 10.9% compared to the C1-C4 hydrocarbon yield after 1 hour (82.7%). The calorific value of C1-C4 hydrocarbons after 1 hour was 41.1 MJ / Nm³. 3 ) and the C1-C4 hydrocarbon heat output after 24 hours (44.5 MJ / Nm³) 3 ) is 3.4 MJ / Nm 3 It increased.

[0097] ·Comparative example 2 (catalyst F) As shown in Table 3, the hydrocarbon yield after 24 hours (81.8%) decreased by 5.1% compared to the hydrocarbon yield after 1 hour (86.9%), and the C1-C4 hydrocarbon yield after 24 hours (80.9%) decreased by 6.0% compared to the C1-C4 hydrocarbon yield after 1 hour (86.9%). The calorific value of C1-C4 hydrocarbons after 1 hour was 40.2 MJ / Nm³. 3 ) and the C1-C4 hydrocarbon heat output after 24 hours (41.4 MJ / Nm³) 3 ) is 1.2 MJ / Nm 3 It increased.

[0098] From the above, it was found that in Examples 2 and 3 (catalysts B and C), a hydrocarbon yield of approximately 75-80% and a C1-C4 hydrocarbon yield of approximately 72-78% were obtained even after 24 hours. Therefore, the catalyst for producing high-calorific value fuel gas of the present invention was found to have excellent durability.

[0099] Examples 2 and 3 (catalysts B and C) both had lanthanum added (5.0 to 10 parts by mass), while Comparative Example 2 (catalyst F) did not contain lanthanum. Therefore, it was observed that the addition of lanthanum increased the calorific value of C1-C4 hydrocarbons.

[0100] Furthermore, the configurations disclosed in the above embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with configurations disclosed in other embodiments, as long as no inconsistencies arise. Moreover, the embodiments disclosed herein are illustrative, and the embodiments of the present invention are not limited thereto, and can be modified as appropriate without departing from the object of the present invention. [Industrial applicability]

[0101] The present invention can be used in a process to produce a high-calorific value fuel gas, which has a higher calorific value per unit volume than methane, from a mixed gas containing at least one of carbon monoxide or carbon dioxide and hydrogen, and which can be used as a raw material for city gas.

Claims

1. A catalyst for producing high-calorific value fuel gas, comprising cobalt supported on an inorganic oxide carrier mainly composed of activated alumina, and lanthanum or manganese, wherein the amount of cobalt supported is 5.0 parts by mass or more and 20 parts by mass or less per 100 parts by mass of the inorganic oxide carrier, if lanthanum is supported, the amount of lanthanum supported is 1.0 part by mass or more and 10 parts by mass or less per 100 parts by mass of the inorganic oxide carrier, and if manganese is supported, the amount of manganese supported is 1.0 part by mass or more and 10 parts by mass or less per 100 parts by mass of the inorganic oxide carrier.

2. The catalyst for producing high-calorific-value fuel gas according to claim 1, comprising 1.0 part by mass or more and 3.0 parts by mass or less of rhenium per 100 parts by mass of the inorganic oxide carrier.

3. The catalyst for producing high calorific value fuel gas according to claim 1 or 2, wherein the inorganic oxide support is a molded body with a particle size of 1.0 mm or more and 20 mm or less.

4. A method for producing a catalyst for high calorific value fuel gas, comprising cobalt supported on an inorganic oxide support mainly composed of activated alumina, and lanthanum or manganese, An impregnation step to obtain an impregnated body by impregnating the inorganic oxide support with an aqueous solution in which cobalt and a water-soluble compound of lanthanum or manganese are dissolved, A drying step of drying the impregnated body to obtain a dried body, A firing step in which the dried body is fired at a temperature of 350°C or higher and 500°C or lower, A method for producing a catalyst for manufacturing high-calorific value fuel gases, including the catalyst mentioned above.

5. A method for producing a catalyst for producing high-calorific value fuel gas, comprising cobalt supported on an inorganic oxide support mainly composed of activated alumina, rhenium, and lanthanum or manganese, An impregnation step to obtain an impregnated body by impregnating the inorganic oxide support with an aqueous solution in which cobalt, rhenium, and a water-soluble compound of lanthanum or manganese are dissolved, A drying step of drying the impregnated body to obtain a dried body, A firing step in which the dried body is fired at a temperature of 350°C or higher and 500°C or lower, A method for producing a catalyst for manufacturing high-calorific value fuel gases, including the catalyst mentioned above.

6. A method for producing a high calorific value fuel gas, comprising contacting a mixed gas containing at least one of carbon monoxide or carbon dioxide and hydrogen with a catalyst comprising cobalt and lanthanum or manganese supported on activated alumina at a temperature of 225°C to 325°C, to obtain a gas mainly composed of methane, and containing ethane, propane, and butane.

7. A method for producing a high calorific value fuel gas, comprising contacting a mixed gas containing at least one of carbon monoxide or carbon dioxide and hydrogen with a catalyst comprising activated alumina supported with cobalt, rhenium, and lanthanum or manganese at 225°C to 325°C, to obtain a gas mainly composed of methane, and containing ethane, propane, and butane.

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