Catalyst for dry reforming reaction

Abstract

The present invention relates to a dry reforming catalyst, and more particularly to a dry reforming catalyst based on a new concept, which significantly extends catalyst life by significantly suppressing the phenomenon of carbon deposition, the greatest challenge in conventional dry reforming technology, through a new configuration that is the exact opposite of the conventional approach for producing synthesis gas in a reducing gas-based carbon reaction system.

Description

[Technical Field]

[0001] The present invention relates to a reducing gas-based dry reforming catalyst, and more particularly to a new concept reducing gas-based dry reforming catalyst for carbon-carbon reaction systems, which has a new structure that significantly suppresses carbon deposition and thereby significantly extends catalyst life. [Background technology]

[0002] In recent years, on the one hand, energy issues have become a major social challenge, and on the other hand, excessive emissions of greenhouse gases, such as carbon dioxide, have emerged as a serious environmental problem.

[0003] In order to ensure energy security both domestically and internationally, there is a growing awareness that the development and utilization of new renewable energy sources that can achieve sustainable growth is urgently needed. In addition, various technologies related to the capture and utilization of carbon dioxide are being developed to address environmental issues.

[0004] South Korea is recognized as one of the world's major greenhouse gas emitters, and is facing increasing international pressure to reduce its greenhouse gas emissions.

[0005] Hydrogen energy is being utilized as an important clean energy source of the future that can simultaneously solve environmental problems such as global warming and problems related to energy dependency, and securing the technology to utilize carbon dioxide as a circulative carbon resource has become an important research topic.

[0006] Generally, methods for producing synthesis gas consisting of hydrogen and carbon monoxide include methods that use fossil fuels such as natural gas, and methods that produce synthesis gas from biomass such as sewage sludge and food waste. Among these synthesis gas production methods, the use of renewable energy from biomass such as carbon dioxide and methane gas is economically advantageous.

[0007] Conventionally, methods for producing synthesis gas from these biogases, such as dry reforming, wet reforming, and combined reforming, which are summarized by the following reaction formulas, have been known.

[0008] Dry reforming: CO2 + CH4 → 2CO + 2H2O (ΔH = 261 kJ / mol)

[0009] Wet reforming: H2O+CH4→3H2+CO(ΔH=226kJ / mol)

[0010] Complex reforming: CO2 + 3CH4 + 2H2O → 4CO + 8H2 (ΔH = 712 kJ / mol)

[0011] Among the reforming reactions using reducing gases as mentioned above, dry reforming is a synthesis gas production technology that can use the largest amount of CO2 (greenhouse gas) as a raw material among catalytic reforming technologies, and since it is highly effective in reducing greenhouse gases, there is global interest in securing this technology.

[0012] In particular, the dry reforming reaction requires a higher proportion of CO to produce chemical products than other reforming reactions, so if superior reaction technology can be secured, it should have a significant impact on reducing greenhouse gas emissions.

[0013] However, such dry reforming reactions require the use of a catalyst, and dry reforming (DRM) technology, which can reduce greenhouse gas emissions, has a fatal drawback: the short lifespan of the catalyst, making it difficult to commercialize.

[0014] As described above, conventional dry reforming catalysts have been continuously developed for the past 100 years because they can use CO2 as a raw material. However, they still have the problem of extremely limited lifespan due to inactivation of the catalyst surface and breakdown of the catalyst formulation.

[0015] Therefore, when using a dry reforming catalyst, the catalyst's operating life is rarely longer than 1,500 to 2,000 hours. Therefore, although various ideas have been proposed to extend the catalyst's operating life in dry reforming reactions, there are currently no technical approaches available other than extending the catalyst's operating life by using a specific catalyst composition.

[0016] As an existing catalyst for dry reforming reactions, Korean Patent No. 10-2194440 proposes a catalyst for dry reforming of biogas that contains a metal oxide support containing hydroxyl groups on the surface of the catalyst and at least one active material selected from nickel (Ni), cobalt (Co), ruthenium (Ru), palladium (Pd), iridium (Ir), platinum (Pt), and rhodium (Rh), and that has excellent catalytic activity and long-term stability.

[0017] Furthermore, Korean Patent Publication No. 10-2022-0034712 proposes a catalyst for dry reforming of methane prepared by coprecipitation using a nickel precursor, a magnesium precursor, and an aluminum precursor, and Korean Patent Registration No. 10-2053978 proposes a catalyst for dry reforming using a catalyst of Sr1-yYyTi1-xRuxO3-δ (where x is greater than 0 and less than 1, y is greater than 0 and less than 0.1, and δ is greater than 0 and less than 1).

[0018] In addition, Korean Patent No. 10-2958429 proposes a catalyst for dry reforming of biogas in which the Cr site of LaCrO3 is doped with a transition metal such as ruthenium (Ru) or iridium (Ir), resulting in a catalyst with excellent resistance to carbon deposition and high activity. Korean Patent No. 10-1457098 proposes a homogenous catalyst in which yttrium and ruthenium are doped into the perovskite lattice of SrTiO3 to form a single phase.

[0019] However, although some of these existing catalysts for dry reforming of biogas are being pursued for long-term use, the maximum reported catalyst life is less than 1,000 hours, and no technology has yet been presented that guarantees sufficient catalyst life.

[0020] In fact, even the catalysts proposed for dry reforming reactions that extend the life of existing catalysts have a limit of use of only 500 to 1,000 hours, with a maximum of 1,000 hours. Therefore, solving this problem is still considered an urgent issue, but no technology that can overcome this problem has yet been proposed worldwide. [Prior art documents] [Patent documents]

[0021] [Patent Document 1] Korean Patent Registration No. 10-2194440 [Patent Document 2] Korean Patent Publication No. 10-2022-0034712 [Patent Document 3] Korean Patent No. 10-2053978 [Patent Document 4] Korean Patent No. 10-2958429 [Patent Document 5] Korean Patent Registration No. 10-1457098 Summary of the Invention [Problem to be solved by the invention]

[0022] The present invention aims to solve the above-mentioned conventional problems in the configuration of a catalyst for a dry reforming reaction in a carbon reaction system for reforming carbon dioxide and the like, and to provide a catalyst for a dry reforming reaction that can significantly extend the catalyst life.

[0023] SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a catalyst having excellent physical properties applicable to a carbon reaction-based dry reforming reaction using a reducing gas.

[0024] Another object of the present invention is to provide a new concept catalyst for dry reforming reactions, which causes almost no carbon deposition and has a semi-permanently extended catalyst life.

[0025] Another object of the present invention is to provide a method for producing a catalyst for dry reforming reaction based on a new concept, which extends the catalyst life so that it can be used semi-permanently.

[0026] In addition to the above-mentioned objects, the present invention can also include various technical results that are not disclosed herein but are attributable to the operational effects achieved by the configuration of the present invention. [Means for solving the problem]

[0027] In order to achieve the above object of the present invention, the present invention provides a catalyst for a dry reforming reaction of a reducing gas-based carbon reaction system, which satisfies the following Equations 1 and 2, and in which a metal oxide catalyst is dispersed on a support at a concentration of catalytically active components such that the value A in Equation 2 is within a range of values ​​that maintain a minimum value under reaction equilibrium conditions that maintain a catalytic reaction: [Formula 1] r=k·C [Formula 2] k=A·exp(Ea / RT) In the above formulas 1 and 2, r represents the reaction rate, k represents the reaction rate constant, and C represents the concentration of the reactant. A is the reaction frequency factor, Ea is the activation energy, R is the gas constant, and T is the temperature.

[0028] According to a preferred embodiment of the present invention, the metal oxide may be contained in an amount of 4% by weight or less relative to the support.

[0029] According to a preferred embodiment of the present invention, the dispersion of the metal oxide may include a form in which an adhesive for fixing an active ingredient is dispersed in the support, and the metal oxide active ingredient is fixed and dispersed on the adhesive.

[0030] According to a preferred embodiment of the present invention, at least one of alumina sol, silica sol, and zirconia sol can be preferably used at a low concentration, preferably about 1 to 15% by weight, more preferably about 5 to 10% by weight, as an adhesive for fixing catalytically active components.

[0031] According to a preferred embodiment of the present invention, the metal oxide is at least one selected from the group consisting of oxides of nickel, cobalt, iron, copper, vanadium, molybdenum, platinum-based metals, cerium, ruthenium, rhodium, palladium, and zirconium.

[0032] In another embodiment, the present invention provides a catalyst for dry reforming reactions of a reducing gas-based carbon reaction system, the catalyst comprising a support on which an adhesive for fixing an active component is dispersed, and a metal oxide active component fixed in a dispersed state on the adhesive.

[0033] The present invention also provides a method for preparing a catalyst for dry reforming reactions in a reducing gas-based carbon reaction system, the method comprising the steps of coating metal oxide particles on the surface of a support, supporting and drying the active metal oxide, and calcining and stabilizing the active component. [Effects of the Invention]

[0034] As described above, the dry reforming catalyst according to the present invention has an effect of being usable for a long period of time, almost semi-permanently, since the catalyst has a life of more than tens of thousands of hours while using a much smaller amount of metal oxide than conventional catalysts.

[0035] The present invention uses a differentiated technology that applies an approach that is the exact opposite of the conventional catalyst preparation method of supporting an excessive amount of catalyst to enhance catalytic performance, thereby achieving a completely different concept of the invention, saving materials used, and at the same time achieving a surprising effect of extending the catalyst life. [Brief explanation of the drawings]

[0036] [Figure 1] 1 is a graph showing the characteristics of the reaction equilibrium during the catalytic reaction process and the tendency of carbon deposition in a dry reforming reaction of a reducing gas-based carbon reaction system. [Figure 2] FIG. 1 is a diagram illustrating the chemical reaction concept showing the occurrence of carbon deposition due to the reaction mechanism of the dry reforming reaction of a reducing gas-based carbon reaction system, and an effective application concept for the use of a catalyst for the dry reforming reaction. [Figure 3] FIG. 1 is a simplified cross-sectional view illustrating a comparison between a conventional catalyst structure in which the active components of the catalyst are directly attached to the support (Structure A) and a new concept catalyst structure according to the present invention in which the active components of the catalyst are attached to the adhesive and then dispersed and fixed on top of it (Structure B). [Figure 4] FIG. 10 is a graph showing the results of measuring catalyst life when a dry reforming reaction is performed using carbon dioxide and methane gases using a reducing gas-based dry reforming reaction catalyst prepared according to one embodiment of the present invention, compared with the results when a conventional catalyst is used. [Figure 5] 1 is a photograph comparing the catalyst state after a dry reforming reaction was carried out for 800 hours using the catalyst of the present invention and a conventional catalyst. [Figure 6] FIG. 10 is a graph showing the results of measuring catalyst life when a dry reforming reaction is carried out using carbon dioxide and methane gases using a reducing gas-based dry reforming reaction catalyst prepared by a method according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0037] The present invention will be described in more detail below with reference to an embodiment.

[0038] The present invention relates to a new concept catalyst for dry reforming reactions that significantly extends catalyst life by using a minimum amount of catalytically active components in constructing a catalyst for a reducing gas-based dry reforming reaction.

[0039] In the present invention, the term "reducing gas" is defined as a reducing agent used in a carbon reaction system, such as reducing CO to produce synthesis gas, and generally refers to a gaseous substance. Examples of reducing gases include hydrocarbons such as methane, ethane, and propane, mixtures of these, and compounds containing these compounds. Reducing gases can also include mixtures of CH, CO, H, O, and N. Reducing gases typically include carbonaceous biogas, industrial by-product gases produced during industrial activities, carbonaceous mixed gases, greenhouse gases such as methane and carbon dioxide, unreacted materials, by-products, and volatile organic compounds generated in factories.

[0040] In the present invention, the term "for dry reforming reactions" refers to applications including not only pure dry reforming reactions but also reactions to which a part of dry reforming is applied or included, such as composite reforming reactions.

[0041] Accordingly, the present invention features a novel configuration of catalyst for use in reforming reactions, such as dry reforming reactions to produce synthesis gas based on gases such as carbon dioxide and methane.

[0042] In the present invention, as a result of extensive research into extending the service life of catalysts in dry reforming reactions, we have overcome the current situation where there are insufficient technical approaches other than extending the service life by using a specific catalyst composition, and have come to propose a catalyst configuration based on a new concept.

[0043] In particular, the present invention has confirmed that in the case of dry reforming catalysts, the cause of catalyst surface deactivation and formulation damage is due to coking, and the present invention is characterized by being able to extend the catalyst life by solving the problem of coking.

[0044] In conventional wet reforming, the water used as a feedstock is a stronger oxidant than carbon dioxide, the feedstock in dry reforming. Therefore, it easily reacts with deposited carbon and suppresses carbon deposition. Therefore, the amount of active metal in the catalyst is typically added in excess, such as 5% by weight or more or 10% by weight or more. This is because, as the amount of active metal in a catalyst increases, the number of reaction active sites generally increases, allowing for more rapid and extensive contact with reactants, thereby increasing the reaction conversion rate. To achieve this, existing processes have produced catalysts containing excess metals. Therefore, dry reforming catalysts developed to date have retained the concept of using excess active metals from existing wet reforming processes, but have utilized methods that utilize the properties of the metal, promoter, and support in the catalyst for improvement, making it difficult to resolve the issue of carbon deposition.

[0045] Breaking away from this conventional notion, the present invention started from the premise that in order to reduce carbon deposition, the generation of solid carbon generated during the dry reforming reaction must be suppressed. As a result of studying the characteristics of the reaction process, the surprising result was obtained that it is necessary to adjust the reaction frequency factor in the dry reforming reaction using a catalyst.

[0046] According to a preferred embodiment of the present invention, it has been confirmed that the probability of carbon deposition cannot be reduced by using only the amount of catalytically active components that reaches reaction equilibrium, based on the relationship between Equation 1 and Equation 2. This is a completely new conclusion that is the complete opposite of the conventional idea that catalyst development requires the use of a large amount of catalyst to only improve the performance of the reforming reaction.

[0047] Therefore, according to a preferred embodiment of the present invention, in order to realize the concept of the present invention, it is necessary to take a development approach that is the exact opposite of the current development approach, unlike the catalyst configuration methods currently proposed for dry reforming reactions.

[0048] As described above, the present invention has found and solved the problem that the use of a catalyst in a dry reforming reaction using a reducing gas causes carbon deposition on the catalyst surface due to coking, which leads to catalyst deactivation and damage, resulting in a rapid shortening of catalyst life.

[0049] According to the present invention, it can be confirmed from the following reaction formula that carbon generated when a reforming reaction is carried out using a dry reforming catalyst with a reducing gas-based carbon reaction system is generated and removed by carbon deposition on the surface of the catalyst.

[0050] [Reaction scheme] Decomposition of CH4: CH4 ⇔ C(s) + 2H2 Dissociation of CO: 2CO⇔C(s)+CO2 CO2 gasification: C + CO2 ⇔ 2CO

[0051] Therefore, the present invention has been completed based on the fact that the life of the catalyst can be extended by solving the problem of carbon deposition on the catalyst for dry reforming reaction.

[0052] According to a preferred embodiment of the present invention, the dry reforming catalyst of the present invention reaches reaction equilibrium, but the new catalyst configuration results in new physicochemical properties of the catalyst, which virtually eliminates carbon deposition that occurs during the forward reaction, thereby significantly extending the catalyst life and enabling it to be used almost semi-permanently.

[0053] According to a preferred embodiment of the present invention, the reforming reaction on the dry reforming catalyst is highly equilibrium, for example at 1 bar, and therefore, the generation of a pressure difference adversely affects the reaction and carbon deposition.

[0054] According to the present invention, the rate at which carbon deposition occurs on a catalyst during a dry reforming reaction can accelerate as the temperature decreases, so maintaining temperature can be an important factor. Furthermore, since the rate of carbon deposition accelerates as the pressure increases even at the same temperature, it is necessary to prevent the occurrence of a pressure difference.

[0055] According to a preferred embodiment of the present invention, the catalytic reaction for dry reforming indicates the conversion rate by the equilibrium between the forward and reverse reactions. Therefore, in order to effectively advance the catalytic reaction, it is necessary to consider each of the forward and reverse reactions. For example, the main reaction that produces carbon (C) is CO dissociation, which occurs in the low temperature region. However, it has been found that the temperature drop during endothermic reaction in this reaction can be the main cause of carbon deposition.

[0056] Therefore, in the existing dry reforming reaction based on reducing gas using a catalyst, carbon deposition occurs on the catalyst used in the reforming reaction, and in order to prevent this carbon deposition, the dissociation of CO must be suppressed. In other words, we have gained new insight that optimal control of the forward reaction that causes carbon deposition is necessary while maintaining reaction equilibrium.

[0057] As mentioned above, the characteristics of the catalytic reaction for dry reforming can be seen in the graph in Figure 1, which shows the characteristics of the reaction equilibrium and the tendency for carbon deposition, which indicates a serious problem of shortened lifespan.

[0058] The present invention aims to solve these problems by thoroughly examining the existing catalytic reactions for dry reforming and finding a new application concept for the catalyst, which can be said to be an important feature of the present invention.

[0059] Furthermore, according to a preferred embodiment of the present invention, since the catalyst temperature and reactant supply concentration are the same during the dry reforming reaction, if these are made constant, the variable becomes a pre-exponential factor, which is related to the collision frequency of the reactants. Therefore, it has been surprisingly discovered that by adjusting the number of active components of the catalyst that induces the catalytic reaction, it is possible to control the reaction rate, and by maintaining reaction equilibrium and minimizing the forward reaction rate, carbon deposition can be resolved.

[0060] According to a preferred embodiment of the present invention, the technical features of the present invention are diagrammed in terms of a chemical reaction concept as shown in FIG.

[0061] FIG. 2 is a simplified schematic diagram of the chemical reaction concept illustrating the generation of carbon deposition due to the reaction mechanism of the reducing gas-based dry reforming reaction, and the effective application concept for the use of catalysts for the dry reforming reaction.

[0062] Therefore, based on such factual considerations, the correlations between the process conditions of the dry reforming reaction, temperature, constants, variables, and reaction rate control can be set as in the following equations 1 and 2 to prevent carbon deposition.

[0063] [Formula 1] r=k·C

[0064] [Formula 2] k=A·exp(Ea / RT)

[0065] In the above formula, the elements r, k, C, A, Ea, R, and T are the same as those defined above.

[0066] In particular, the present invention is characterized in that the metal oxide catalyst is dispersed on a support at a concentration of catalytically active components at a level that satisfies the above-mentioned formula 1 and formula 2, and the value A in formula 2 is in a range of values ​​that maintain a minimum value under reaction equilibrium conditions that maintain the catalytic reaction.

[0067] According to a preferred embodiment of the present invention, in relation to extending the catalyst life, it is preferable to maintain the value of the rate constant according to temperature in the above-mentioned relationship between Equation 1 and Equation 2 only at the equilibrium reaction level, and for this purpose, it is preferable to adjust the number of active components of the catalyst in order to adjust the reaction frequency factor A, which can be adjusted within the equilibrium constant.

[0068] According to a preferred embodiment of the present invention, in order to adjust the number of active components in these catalysts, it is necessary to support a minimum amount of active components. To this end, it has been concluded that the metal oxide used as the catalytically active component in the dry reforming reaction should preferably be contained in an amount of 4 wt % or less, more preferably 3 wt % or less, relative to the support.

[0069] According to a preferred embodiment of the present invention, when the above formulas 1 and 2 are satisfied, the metal oxide, which is the active component attached to the support constituting the catalyst, can be contained in an amount of 4 wt% or less, preferably 3 wt% or less, and more preferably 2 wt% or less per unit mass of the support. For example, it is possible to load the metal oxide in an amount of 0.1 to 3 wt%, more preferably 0.5 to 3 wt%, and most preferably 0.5 to 2 wt%.

[0070] According to a preferred embodiment of the present invention, the metal compound is preferably at least one of nickel, cobalt, iron, copper, vanadium, molybdenum, platinum-based metals, cerium, and zirconium.

[0071] According to a preferred embodiment of the present invention, the catalyst used in the dry reforming catalytic reaction can be configured to have a shape with an extremely low specific surface area and low pressure drop, for example, by using a precursor solution of an ionized catalytically active component.

[0072] According to a preferred embodiment of the present invention, the catalyst used in the dry reforming catalytic reaction preferably has an active component supported on a support that exhibits high heat resistance even at high temperatures.

[0073] In the present invention, both of these cases are referred to as a support.

[0074] According to a preferred embodiment of the present invention, the present invention does not require the use of a porous support or a support with a high specific surface area. The excellent effects of the catalyst supported with a small amount of active component, as desired by the present invention, can be achieved without the use of a porous or high specific surface area support. In this case, ceramic or metal supports such as cordierite or silicon carbide can be used as the support. These supports preferably have a channel structure or a low-pressure differential packing structure that facilitates the flow of reactants. Specific examples of support materials that can be used include Al, Zr, Si, Ti, Mg, Ce, and La. These supports can be used in the form of oxides such as SiO2, Al2O3, MgO, ZrO2, SeO2, and TiO2.

[0075] As described above, in the past, in order to support a large amount of catalytically active components, a support with a high specific surface area was used or a large amount of catalyst was formed and applied. However, the present invention is characterized by using a very limited concentration of catalytically active components to minimize it.

[0076] Therefore, according to a preferred embodiment of the present invention, the catalyst for dry reforming reactions of the present invention can disperse and adhere active components to a conventional support in a smaller amount than conventionally, for example, within 4 wt % per unit mass of the support.

[0077] According to a preferred embodiment of the present invention, the catalyst structure is such that the number of catalytically active components is very limited to satisfy the reaction equilibrium. This means that the catalyst can be manufactured in a form completely different from, or with the opposite technical concept to, the conventional reforming catalyst development, which has been used to improve performance by using a carrier with a high specific surface area to support a large amount of catalytically active components or by molding a large amount of catalyst.

[0078] According to a preferred embodiment of the present invention, such a dry reforming catalyst can be prepared by, for example, washing the surface of a support or coating active metal oxide particles on the surface of a support, supporting and drying the active metal oxide, and calcining and stabilizing the active metal oxide component.

[0079] Meanwhile, as another example of the catalyst configuration of the present invention, the catalyst for a dry reforming reaction of a reducing gas-based carbon reaction system according to the present invention may be configured in a dispersed and fixed form by attaching an adhesive for fixing an active component to a support to improve the durability of the catalytic active component at high temperatures, and then attaching the active component thereon.

[0080] According to a preferred embodiment of the present invention, in such a case, the above-mentioned formulas 1 and 2 can be applied, or the desired purpose can be achieved by such a catalyst configuration without applying them. However, if the above-mentioned adhesive for fixing the active ingredient is used while satisfying the formulas 1 and 2, better catalytic properties can be obtained and the catalyst life can be further extended.

[0081] Therefore, according to a preferred embodiment of the present invention, the active ingredient is not directly attached to a support, but is first dispersed and attached to an adhesive, and then the active ingredient is attached to the adhesive. This means that the catalyst can be produced in a manner completely different from the conventional method of attaching an active ingredient to a support. Such a preferred structure of the present invention can be produced in a novel form, for example, as shown in Figure 3.

[0082] 3 is a simplified cross-sectional view comparing a conventional catalyst structure in which the active ingredients of the catalyst are directly attached to the support (Structure A) with a novel catalyst structure according to the present invention in which the active ingredients of the catalyst are attached and dispersed and fixed on the adhesive (Structure B). The present invention can use either of these two structures, but Structure B is more advantageous.

[0083] According to a preferred embodiment of the present invention, the long-term usable dry reforming catalyst of the present invention can be used for an extremely long period of time by dispersing the active component in a small amount sufficient to reach reaction equilibrium, preferably within 4% by weight, more preferably 0.1 to 3% by weight per unit mass of the support, but the performance of the catalyst may gradually deteriorate after several thousand hours. However, even this small deterioration can provide far superior effects compared to conventional catalysts.

[0084] According to a preferred embodiment of the present invention, in order to prevent the performance of the catalyst from deteriorating over a long period of use as described above, stabilization of the catalytically active components is required.

[0085] According to the present invention, in order to stabilize the catalytically active component, the catalytically active component is not immediately fixed to the support, but rather the adhesive is applied, and then the active component is firmly fixed onto the adhesive, thereby making it possible to prevent the catalytic activity from decreasing even when the catalyst is used for an extremely long period of time.

[0086] According to a preferred embodiment of the present invention, at least one of low-concentration alumina sol, silica sol, and zirconia sol can be used as an adhesive for fixing the active ingredient, and these adhesives are used by dispersing them on the surface of the support for fixing the active ingredient. For example, such adhesives can be used at a ratio of 10% by weight per unit area of ​​the support, preferably 5% by weight or less. For example, they can be used at 5 to 10% by weight.

[0087] According to a preferred embodiment of the present invention, the preparation of a catalyst for adhering an active component to an adhesive agent can include the steps of cleaning the surface of a support or coating the surface of a support with active metal oxide particles, supporting and drying the active metal oxide, and calcining and stabilizing the active metal oxide component. In this case, however, it is necessary to disperse the active metal oxide component at a concentration of catalytically active component that satisfies the above formulas 1 and 2 and that the A value in formula 2 is within a range that maintains a minimum value under reaction equilibrium conditions that maintain the catalytic reaction. For example, the catalyst can be prepared by cleaning the surface of the support, supporting alumina sol on the support, drying and calcining, supporting a precursor of the active component, and drying and calcining.

[0088] As described above, according to the present invention, unlike the conventional technology, the catalyst life can be extended by at least several tens of times based on a technology that uses a much smaller amount of catalytically active components than conventional catalysts for dry reforming reactions in reducing gas-based carbon reaction systems.

[0089] For example, the dry reforming reaction catalyst of the present invention can be used for at least 1,500 hours, or at least 2,000 hours, 3,000 hours, or 5,000 hours or more, based on a conversion rate of 50% to 60%, preferably 70% or more, and typically can be used for at least 10,000 hours, preferably 20,000 hours or more.

[0090] The catalyst of the present invention has maintained its catalytic activity well since the present invention, and it is recognized that it can be used substantially semi-permanently.

[0091] Therefore, the present invention simplifies the operation of the process by using a small amount of active ingredient, which is economical and allows for an extremely long catalyst replacement period.

[0092] The following are the results of comparative experiments on catalysts conducted to demonstrate the functions and effects of the present invention. The following examples are merely illustrative of the present invention, and the present invention should not be construed as being limited by the following examples.

[0093] [Example 1] The weight of the catalytic active components (active components: Co, Ni) that determine the A factor in the above equations (1) and (2) proposed in the present invention was adjusted to 0.5 to 3 wt % (1.5 wt %). Using this reducing gas-based dry reforming catalyst, a dry reforming reaction was carried out using carbon dioxide and methane gas under the conditions of a reaction temperature of 900°C, a feed CO2 / CH4 ratio of 1, and a space velocity of 4,200 h-1. These conditions were maintained while the dry reforming reaction was continued, and the catalyst life, which is the usable time, was measured.

[0094] The results are shown in Figure 4.

[0095] FIG. 4 shows the results of measuring catalyst life when a dry reforming reaction using carbon dioxide and methane gas is performed using a catalyst for a dry reforming reaction of a reducing gas-based carbon reaction system prepared according to one embodiment of the present invention, in comparison with a conventional catalyst.

[0096] As a result of this experiment, it was confirmed that the catalyst has a lifespan of at least 1,500 hours, preferably 2,000 hours or more, or 10,000 hours or more, which is approximately 2 to 4 times longer than the conventional 500 to 1,000 hours.

[0097] In addition, the dry reforming reaction was carried out for 800 hours using the catalyst of the present invention and a conventional catalyst, and the catalyst state was confirmed. The results are shown in Figure 5.

[0098] Referring to FIG. 5, it can be seen that the conventional catalyst is damaged and unusable, whereas the catalyst of the present invention maintains its shape and can be used for a long period of time.

[0099] [Example 2] A catalyst for dry reforming reaction was prepared by adjusting the weight of catalytically active components (active components: Co, Ni) to 0.5-3 wt% (2 wt%) on a support (SiO2) to which a small amount (within 2 wt%) of adhesive (alumina sol) had been attached. Using carbon dioxide and methane gas, a continuous dry reforming reaction was carried out under the same conditions as in Example 1, and the usable life of the catalyst was measured.

[0100] The results are shown in Figure 6.

[0101] According to the experimental results shown in Figure 6, the catalyst used was confirmed to have a durable life of at least 10,000 hours, which is 10 to 20 times longer than the maximum life of conventional catalysts.

[0102] From the results of these examples, it has been experimentally confirmed that the novel dry reforming catalyst of the present invention can be used for a long period of time, almost indefinitely, while using a small amount of active components, which was hitherto unimaginable. Such an extension of catalyst life can bring about a significant technological leap in terms of economical efficiency and process reduction compared to the use of conventional catalysts.

[0103] It is expected that the development of such a semi-permanent catalyst in the present invention will make an innovative contribution to solving the problem of carbon neutrality.

Claims

1. A catalyst for a dry reforming reaction of a reducing gas-based carbon reaction system, the catalyst comprising a metal oxide catalyst dispersed on a support at a concentration of catalytically active components that satisfies the following formulas 1 and 2, and in which the value A in formula 2 is within a range of values ​​that maintain a minimum value under reaction equilibrium conditions that maintain a catalytic reaction: [Formula 1] r = k C [Formula 2] k=A・exp(Ea / RT) (In the above formula 1 and formula 2, where r is the reaction rate, k is the reaction rate constant, and C is the concentration of the reactant. A is the reaction frequency factor, Ea is the activation energy, R is the gas constant, and T is the temperature.

2. 2. The catalyst for dry reforming reactions according to claim 1, wherein the dispersion of the metal oxide includes a form in which an adhesive for fixing the active component is dispersed in the support, and the metal oxide active component is fixed and dispersed on the adhesive.

3. 2. The catalyst for dry reforming reactions according to claim 1, wherein the metal oxide active component is dispersed and fixed on the support, an adhesive for fixing the active component is dispersed on the support, and the metal oxide active component is fixed and dispersed on the adhesive.

4. 2. The dry reforming catalyst according to claim 1, wherein the metal oxide is contained in an amount of 4% by weight or less based on the weight of the support.

5. 2. The dry reforming reaction catalyst according to claim 1, wherein the metal oxide comprises at least one selected from the group consisting of oxides of nickel, cobalt, iron, copper, vanadium, molybdenum, platinum-based metals, cerium, ruthenium, rhodium, palladium, and zirconium.

6. 4. The catalyst for dry reforming reactions according to claim 3, wherein the adhesive for fixing the active component includes at least one of alumina sol, silica sol, and zirconia sol.

7. 2. The dry reforming catalyst according to claim 1, wherein the catalyst has a life of 1,500 hours or more based on the time of the reforming reaction using the catalyst.

8. 2. The dry reforming catalyst according to claim 1, wherein the catalyst has a life of 2,000 hours or more based on the time of the reforming reaction using the catalyst.

9. coating particles of an active metal oxide on the surface of a support; supporting and drying the active metal oxide; and calcining and stabilizing the active metal oxide component; In a reducing gas-based carbon reaction system, the following formulas 1 and 2 are satisfied under dry reforming reaction conditions: a step of dispersing particles of the active metal oxide on the support at a concentration of the catalytically active component such that the value A in Equation 2 is within a range of values ​​that maintain a minimum value under reaction equilibrium conditions that maintain the catalytic reaction. [Formula 1] r = k C [Formula 2] k=A・exp(Ea / RT) (In the above formula 1 and formula 2, where r is the reaction rate, k is the reaction rate constant, and C is the concentration of the reactant. A is the reaction frequency factor, Ea is the activation energy, R is the gas constant, and T is the temperature.

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