KR100553701B1 - High active catalyst for synthetic gas generation, preparing method thereof and the process for preparing synthetic gas using the same - Google Patents

Abstract

The present invention relates to a high-efficiency catalyst for syngas production, a method for preparing the same, and a process for preparing the syngas using the same. The catalyst of the present invention is a first group catalyst and a porous support simultaneously supporting noble metals and alkaline earth metals on a porous support having heat resistance. It comprises a second group catalyst carrying a precious metal having excellent low-temperature synthesis gas generating power, and is prepared by uniformly grinding the first group catalyst and the second group catalyst. In the case of using the catalyst according to the present invention, since the reaction start temperature is lowered and a separate activation process is not required, the configuration simplification and start-up time of the syngas production process can be significantly reduced.

Syngas, Mixed Catalysts, Hydrocarbons, Precious Metal Catalysts

Description

High active catalyst for synthetic gas generation, preparing method etc. and the process for preparing synthetic gas using the same}             

1 shows a conventional syngas production process diagram using a separate reforming reactor.

2 shows a conventional syngas production process diagram using an integrated reforming reactor.

3 is a graph comparing catalyst performance according to Examples 1 and 2 and Comparative Example 1. FIG.

4 is a graph comparing catalyst performance according to Example 3 and Comparative Example 2. FIG.

5 is a graph of catalytic performance according to Example 4.

6 is a graph of catalytic performance according to Example 5.

7 is a graph of catalyst performance according to Examples 6-7.

8 is a graph of catalyst performance according to Example 8 and Comparative Example 3.

9 is a graph of catalyst performance according to Example 1 and Comparative Example 4.

10 is a graph of catalytic performance according to Example 9.

The present invention relates to a high activity catalyst for syngas production, a method for producing the same, and a process for producing a syngas using the same, and more particularly, a syngas suitable for a small and medium scale syngas production apparatus requiring frequent operation and shutdown. It relates to a high activity catalyst for production, a method for producing the same, and a process for preparing a synthesis gas using the same.

Steam reforming and partial oxidation reactions of hydrocarbons are mainly used in the synthesis gas production process. In view of the high concentration of hydrogen, steam reforming, which proceeds as in Scheme (1), is preferred, and in processes requiring frequent shutdown and simplification / miniaturization, the partial oxidation reaction represented by the general scheme (2) is used.

Scheme 1

CH ₄ + H ₂ O → CO + 3H ₂ , ΔH ⁰ ₂₉₈ = +206 kJ / mol

Scheme 2

CH ₄ + 1 / 2O ₂ → CO + 2H ₂ , ΔH ⁰ ₂₉₈ = -36kJ / mol

There are two paths of partial oxidation reaction: direct partial oxidation reaction that generates syngas in a single reaction path as in reaction equation (2) and indirect partial oxidation reaction which proceeds sequentially through reaction equations (3) to (5). Although it is impossible to determine whether the reforming reaction proceeds on the surface of each catalyst directly or simultaneously with the indirect partial oxidation reaction, the contribution of the synthesis gas to the formation of the synthesis gas, but the reactor temperature is easier to control than the conventional steam reforming reaction. Research is ongoing. In particular, compatibility is expected in systems requiring frequent small and medium start and stop (Fig. 2).

Scheme 3

CH ₄ + 2O ₂ → CO ₂ + 2H ₂ O, ΔH ⁰ ₂₉₈ = -801 kJ / mol

Scheme 4

CH ₄ + CO ₂ → 2CO + 2H ₂ , ΔH ⁰ ₂₉₈ = +247 kJ / mol

Scheme 5

CH ₄ + H ₂ O → CO + 3H ₂ , ΔH ⁰ ₂₉₈ = +206 kJ / mol

As shown in FIG. 1, combustion heat, carbon dioxide, and steam generated by a hydrocarbon oxidation reaction are generated in the oxidation catalyst layer as shown in FIG. Processes for carrying out carbon dioxide reforming and steam reforming are known as in (5) (Korean Patent Laid-Open Publication Nos. 1999-0049702, and 1999-0046013). Meanwhile, for the purpose of simplifying the process, a process of simultaneously reforming a hydrocarbon and simultaneously reforming a hydrocarbon in a single reactor has been announced (KH Hofstad et al., "Partial oxidation of methane to synthesis gas over a Pt / 10%). Rh gauze ", Catal. Lett., 45, 97-105 (1997)).

At this time, the catalyst used in the reforming reactor as the main catalyst is a noble metal or nickel, a catalyst containing a transition metal, alkali metal or a catalyst of the noble metal has been published, the main concern is the part to obtain the resistance to coke (Hengyong Xu et al., "A study on the reforming of natural gas with steam, oxygen and carbon dioxide to produce syngas for methanol feed stock", J. Molecular Catalysis A: Chemical, 147, 41--46 ( 1999).

A study by AM O'Connor and JRH Ross found that coke resistance was superior when using a noble metal catalyst of Pt / ZrO ₂ in carbon dioxide reforming with methane (Aisling M. O'Connor, Julian RH Ross). , "The effect of O ₂ addition on the carbon dioxide reforming of methane over Pt / ZrO ₂ catalysts", Catalysis Today, 46, 203--210 (1998)).

According to F.Frusteri et al., Studies on the potassium-modified nickel-supported catalyst (Ni-K / MgO) in the carbon dioxide reforming reaction with methane can provide resistance to coke and thermal stability of nickel depending on the addition of potassium. (F.Frusteri et al., "Potassium-enhanced stability of Ni / MgO catalysts in the dry reforming of methane", Catalysis Communications, 2, 49--56 (2001)).

U.S. Patent 6,312,669 B1 discloses that catalysts containing alkali metals in the support have excellent durability against coke to have an electronegativity of 13 or less as a support for precious metals when producing synthesis gas from hydrocarbons and carbon dioxide.

US Pat. No. 6,293,979 B1 discloses that durability by coke and heat can be ensured when syngas is produced from hydrocarbons using a catalyst carrying an active metal group 8A after supporting an alkali metal on a support. Meanwhile, US Pat. No. 6,293,979 B1 discloses an outer surface of an inert support for catalytic autothermal reforming (hereinafter referred to as “CATR”), which proceeds in the form of supplying oxygen, hydrocarbons, and water to generate heat of reaction. A catalyst in which an alkali metal is supported and then co-precipitated with nickel and cobalt is disclosed.

The catalysts described above have the property of initiating the reaction when the reduction of hydrogen or the reaction gas is heated to a high temperature of 650 ° C. or more for the purpose of activating the catalyst in the reaction initiation step while ensuring resistance to coke.

 However, in the small and medium-sized syngas production system in which frequent start-ups and stops are repeated, it is necessary to start the reactor operation quickly and to minimize the pretreatment device and the heating device of the catalyst in order to simplify / miniaturize. Therefore, there is a need for development of a catalyst for low temperature startup that enables the activity of the catalyst to be exerted at a low temperature to allow a temperature rise by the heat of reaction.

The present inventors have therefore been able to lower the onset temperature for Catalytic Regeneration (CATR) of hydrocarbons and / or alcohols, in particular providing catalysts which do not require an activation step of the catalyst during initial startup.

Accordingly, an object of the present invention is to provide a high activity for a synthesis gas production process in which a first group catalyst having excellent direct partial oxidation power and a second group catalyst having excellent low temperature syngas generation ability are mixed and mixed for hydrocarbon and / or alcohol catalytic reaction. To provide a catalyst.

Another object of the present invention is to provide a method for producing a high activity catalyst for syngas production.                         

Still another object of the present invention is to provide a process for preparing syngas using the catalyst prepared according to the present invention.

Accordingly, the present invention

At least one precious metal selected from the group consisting of Rh, Ru, Pd and Pt and at least one alkaline earth metal selected from Group 2A on the periodic table are Al, Si, Zr, Ti, Ba, Ce, Co, Mg, La, Y And a first group catalyst prepared by supporting a porous support composed of at least one material selected from the group consisting of oxides or oxides thereof. And

At least one or more porous supports selected from the group consisting of Al, Si, Zr, Ti, Ba, Ce, Co, Mg, La, Y and oxides thereof, at least one precious metal selected from the group consisting of Rh, Ru, Pd and Pt Group 2 catalyst supported on

Provided is a high activity catalyst for syngas production comprising a.

In addition, the present invention

Uniformly grinding and mixing the Group 1 catalyst and the Group 2 catalyst; And

Providing the mixed catalyst in a granular or monolithic form or coating it on a metal plate, metal mesh or metal web

It provides a method for producing a high activity catalyst for syngas production, characterized in that it is prepared to include.

Furthermore, the present invention provides a process for producing a synthesis gas, characterized in that the reactants comprising hydrocarbons and / or alcohols, water and air or oxygen are reformed by passing through a catalyst layer comprising the mixed catalyst of the present invention.

Hereinafter, the present invention will be described in detail.

The catalyst for producing highly active syngas according to the present invention is composed of a mixture of two or more kinds of catalysts. The first group catalyst is a catalyst that is prepared to have excellent reforming activity for hydrocarbons, and is a catalyst prepared by simultaneously supporting a noble metal and an alkaline earth metal on a porous support. It is prepared by being supported on a porous support. According to the present invention, the catalyst for preparing a highly active synthesis gas prepared by mixing the first group catalyst and the second group catalyst significantly reduces the configuration and initial startup time of the process because a separate catalyst activation step (reduction) is unnecessary. In addition, the reaction is started at a low temperature is characterized by high reforming performance.

In an embodiment of the present invention, the catalyst of the first group includes at least one noble metal main catalyst selected from the group consisting of Rh, Ru, Pd and Pt and at least one alkaline earth metal promoter selected from group 2A on the periodic table of Al, Si, Zr , Ti, Ba, Ce, Co, Mg, La, Y and at least one material selected from the group consisting of oxides or a catalyst for hydrocarbon reforming prepared by supporting on a porous support composed of oxides thereof. At this time, the alkaline earth metal mixed with the noble metal main catalyst is preferably magnesium or barium.

In addition, the content of the noble metal in the first group catalyst is 0.01 to 5.0% by weight based on the weight of the first group catalyst support, preferably 1.0% by weight or less, more preferably 0.3% by weight or less. In addition, the content of the alkaline earth metal co-precipitated with the noble metal is 0.01 to 15% by weight based on the weight of the first group catalyst support.

In an embodiment of the invention, the second group of catalysts comprises at least one precious metal selected from the group consisting of Rh, Ru, Pd and Pt, Al, Si, Zr, Ti, Ba, Ce, Co, Mg, La, Y and It is a catalyst prepared by being supported on at least one porous support selected from the group consisting of oxides thereof.

The noble metal content in the second group catalyst is 0.01 to 10.0% by weight based on the weight of the second group catalyst support. Preferably 1 to 5% by weight is appropriate, more preferably excellent performance can be obtained when holding 2 to 5% by weight.

The first group catalyst of the present invention can further increase the activity by coprecipitating alkaline earth metals with noble metals on a heat resistant support. For example, as shown in FIG. 4, in the case of the Rh / Mg-Al ₂ O ₃ catalyst disclosed in US Pat. No. 6,293,979 B1, the conversion rate at the reaction temperature of 900 ° C is only 40%, while simultaneously supporting the precious metal and the alkaline earth metal. In case of using the prepared Rh-Mg / Mg-Al ₂ O ₃ catalyst of the present invention, a conversion rate of 99% or more can be obtained at 600 ° C.

On the other hand, in the case of using only the first group catalyst of the present invention, since the overall self-heat of reaction (see Scheme 2) is low, heating up to at least 500 ~ 600 ℃ in the reaction start step is inevitable. However, it can be seen that when the second group catalyst is mixed with the first group catalyst, the reaction temperature can be significantly lowered as shown in FIG. 3 even under the condition of O / C = 1.0.

Comparing the oxidation catalysts of the second group and the first group used in the present invention, the oxidation catalyst according to the first group emphasizes the perfect oxidation power and high temperature durability against hydrocarbons, whereas the catalyst of the second group according to the present invention has a low temperature. Needs to be able to produce syngas (hydrogen, carbon monoxide). The synthesis gas generated thereby activates the first group of reforming catalysts to induce a reforming reaction.

Therefore, the catalyst prepared by mixing the Group 1 catalyst and the Group 2 catalyst can be used in a small system during the synthesis gas production in which the system stops repeatedly. In particular, the initial activation (reduction) process of the catalyst is unnecessary. Has the advantage. When the reaction proceeds to the first group single catalyst of the present invention without a separate activation process (pretreatment), as shown in FIG. 5, different performances are shown in the heating process and the cooling process. That is, when the reduction of the catalyst proceeds by the synthesis gas generated when the reaction proceeds at a high temperature, the reforming activity for hydrocarbons is present up to 400 ℃ when cooled to low temperatures. On the other hand, according to the experimental result of mixing the catalyst of the first group and the second group (Fig. 6) it can be obtained the same activity in the heating and cooling process. That is, according to the use of the mixed catalyst according to the present invention, since a separate catalyst activation step (reduction) is not required, the configuration and initial start-up time of the process can be significantly reduced.

The content of the second group catalyst in the mixed catalyst may be used by mixing 0.1 to 49% of the total weight of the catalyst. However, the content of the noble metal added to the second group catalyst can be maximized price competitiveness by adding or subtracting the added amount depending on the application. In other words, sufficient activity can be obtained even by minimizing the mixing of the second group (less than 5% by weight of the total catalyst content) in the use facility equipped with supplementary facilities to supply the reducing gas separately without frequent start-up stops. As such, when the amount of the second group having a high content of precious metal is lowered, price competitiveness can be doubled.

In addition, it is possible to achieve the object by physically mixing the catalyst belonging to the single group of the first group or the second group. That is, when using a mixture of the same group of composition catalyst than using a single catalyst belonging to the first group or the second group, it is somewhat lower than the catalyst mixed with the catalyst of the first group and the second group, High activity can be obtained as compared to using a single catalyst of the group or the second group. However, when the same group of catalysts are used, the content control of the precious metal is further required. That is, in the catalyst for the purpose of reforming, it is preferable to maintain the content of the noble metal to 0.3% by weight or less so as to have a high dispersion degree, and in the catalyst for obtaining the low temperature reforming role of the hydrocarbon, the content of the noble metal is at least 1% by weight based on the support. In this way, high activity can be obtained when the crystal phase is largely produced.

It would also be possible to prepare by coprecipitation of a noble metal onto the same support without using two supports as in the present invention. However, in the case of a catalyst which is not prepared using a separate support as shown in FIG. 9, the catalyst activity of the present invention shows a big difference. That is, even if the same precious metal is used, different results are shown depending on the support thereof, and in order to obtain reforming activity for hydrocarbons from low temperature, one or more precious metals must be independently present on the separated support.

Experimental results for this catalyst combination are also shown in Examples 6-8 (FIG. 7) when Rh-Mg / when mixing Rh-Mg / Al ₂ O ₃ and Pt-Mg / YSZ, the same first group of catalysts. It is possible to lower the temperature to obtain the same conversion rate than Al ₂ O ₃ or Pt-Mg / YSZ single catalyst 80 ~ 100 ℃. In addition, the catalyst mixed with the second group can also obtain a difference of 170 ° C. based on the temperature indicating a conversion rate of 50% of methane compared to the single component (FIG. 8).

Preferably, however, when hydrocarbons of the first and second groups are mixed, high hydrocarbon conversion can be obtained at lower temperatures.

The catalyst of the present invention is characterized in that it is prepared by uniformly grinding and mixing the Group 1 catalyst and the Group 2 catalyst, and then processing into a granular or monolithic material or coating a metal plate, a metal mesh or a metal web.

The catalyst according to the present invention can be prepared by any method practiced in the art, for example, a method of preparing a first group catalyst and a second group catalyst in a particulate form and physically mixing them, or a ceramic. A method of coating and coating a support having a large external surface area and / or excellent heat transfer at the same time, such as a monolith, a metal plate, a metal mesh, or a metal web, may be used. Most preferably, the first and second group catalysts are mixed The catalyst prepared by the method of processing into a granular or monolithic material which is uniformly ground to 10 μm or less and maintains a higher mixing degree exhibits excellent activity.

In the synthesis gas production of the present invention, the first group of catalyst components prepared by simultaneously carrying a reactant consisting of a hydrocarbon and / or alcohol and oxygen and supporting a precious metal and alkaline earth metal (Group 2A, in particular Mg) on a porous heat-resistant support and There is provided a process for producing a synthesis gas by reforming the catalyst by passing through a catalyst layer comprising a second group of catalyst components having low temperature oxidation and synthesis gas generating power.

The catalyst layer comprises at least one material selected from the group 2A on the periodic table, which is at least one precious metal and an alkaline earth metal selected from the group consisting of Rh, Ru, Pd and Pt, Al, Si, Zr, Ti, Ba, Ce, Co, Mg, La At least one material selected from the group consisting of Y, and oxides thereof, or at least one precious metal selected from the group consisting of Rh, Ru, Pd, and Pt supported on a porous support composed of oxides thereof and Al, Si And uniformly pulverizing the formed catalyst to 10 μm or less including a second catalyst supported on at least one porous support selected from the group consisting of Zr, Ti, Ba, Ce, Co, Mg, La, Y and oxides thereof. They can be mixed and processed into granules or monoliths or coated on metal plates, metal nets or metal webs.

The catalyst according to the invention has a corresponding force according to non-idealities at various operating conditions or at the same time. As shown in FIG. 10, when the dispersion of hydrocarbons, oxygen, and water, which are supplied reactants, is not even or the initial temperature of the reactor, a partial oxidation reaction is performed without supplying water for the purpose of heating the reactor. A method of supplying water or steam after raising to 500-1000 ° C. may also be used. When water was added, the equilibrium conversion was shown, and the hydrocarbon was reformed by steam reforming even after the supply of air or oxygen was stopped after heating to 500 ~ 1000 ° C. This shows the ability of the catalysts according to the invention to various reactor operating conditions and non-idealities.

Hydrocarbons usable in the present invention are selected from the group consisting of aliphatic hydrocarbons, aromatic hydrocarbons, and olefins having 1 to 32 carbon atoms, preferably natural gas (LNG) mainly containing methane, ethane, propane, and 2 to 7 carbon atoms. Liquefied petroleum gas (LPG) with dogs, gasoline, white kerosene, and hydrocarbons vaporized with light oil.

Alcohols usable in the present invention are preferably methanol and / or ethanol.

In addition, the catalyst bed temperature in the catalytic reactor according to the present invention is 400 ~ 900 ℃, the gas space velocity (GHSV) of the reactants is 2,000 ~ 400,000hr ^-1 .

The composition ratio of the reactants consisting of hydrocarbons, alcohols, water and oxygen may vary depending on the operating method of the system, and preferably 0.01 to 4.5 times the molar ratio of the constituent carbon in the hydrocarbon and the molar ratio of the constituent carbon in the hydrocarbon. It consists of 0.01 to 3.5 times the steam.

The present invention can be more clearly understood through the following examples, which are only intended to illustrate the present invention and are not intended to limit the scope of the present invention.

Example

Preparation Example 1; Rh-Mg / Al ₂ O ₃ Catalyst

The metal precursors (KOJIMA CHEMICAL CO., LTD, Rhodium (III) chloride) and precursors were added so that the content of rhodium was 0.1% by weight of the activated alumina as the support, and the content of magnesium was 3% by weight of the activated alumina as the support. JUNSEI, Magnesium nitrate hexahydrate) was prepared by simultaneously dissolving in distilled water. The prepared solution was supported on activated alumina (Aldrich 19996-6, hereinafter Al ₂ O ₃ ) _three times by the incipient wetness method. In order to obtain the uniformity of the active metal, a solution corresponding to the alumina pore volume as a support was added and mixed so that the remaining solution was not absorbed. After mixing the solution, the stirred alumina was dried in a 60 ° C. dryer for 30 minutes, and the impregnation of the precursor was repeated in the same manner as described above. After repeating three times, dried for 24 hours and completed by firing for 4 hours at 500 ℃ kiln. The completed catalyst was designated Rh-Mg / Al ₂ O ₃ .

Preparation Example 2; Rh / Al ₂ O ₃ Catalyst

It prepared as in Preparation Example 1. However, rhodium alone was supported without adding a magnesium precursor. The prepared catalyst was designated as Rh / Al ₂ O ₃ .

Preparation Example 3; Rh-Mg / Mg-Al ₂ O ₃ Catalyst

The catalyst was prepared as in Preparation Example 1. However, the activated alumina was supported by 10% by weight of magnesium, dried and baked at 1000 degrees for 10 hours. Magnesium alone was first supported, and the preparation process of the calcined support was also supported by the initial wetting method, which is the same method as in Preparation Example 1 above. At this time, two kinds of rhodium content of 0.1 wt% and 0.2 wt% were prepared. The completed catalyst was designated as Rh [0.1] -Mg / Mg-Al ₂ O ₃ and Rh [0.2] -Mg / Mg-Al ₂ O ₃ , respectively.

Preparation Example 4; Rh / Mg-Al ₂ O ₃ Catalyst

The catalyst was prepared as in Preparation Example 3. However, the rhodium sole component was supported, and the content of the precursor was adjusted to 0.1 wt% of the support. The completed catalyst was designated Rh / Mg-Al ₂ O ₃ .

Preparation Example 5; Pt-Mg / YSZ Catalyst

It prepared as in Preparation Example 1. However, the active metal was used as a platinum precursor (Hesung Engelhard, H ₂ PtCl ₆ x H ₂ O) and the content was 2% by weight of the support. In addition, YSZ (Aldrich, 464228), a zirconium oxide modified with yttria, was used as a support. The finished catalyst was designated Pt-Mg / YSZ.

Preparation Example 6; Pt / YSZ Catalyst

It prepared in the same manner as in Preparation Example 5. However, no magnesium precursor as a promoter component was added. The finished catalyst is designated Pt / YSZ.

Preparation Example 7; Pt-Rh-Mg / Al ₂ O ₃ Catalyst

It prepared in the same manner as in Preparation Example 1. However, a supported solution was prepared by including a precursor thereof such that the content of platinum was 1 wt% based on the weight of the support as a precious metal. The completed catalyst was designated Pt-Rh-Mg / Al ₂ O ₃ .

The methane reforming activity of the catalysts prepared in Preparation Examples 1-7 and their mixed catalysts was measured.

Examples 1-2

The reforming activity of methane was measured by mixing 0.025 g of the catalyst Rh-Mg / Al ₂ O ₃ of the first group according to Preparation Example 1 and 0.025 g of the catalyst Pt / YSZ of the second group according to Preparation Example 6. The reaction was carried out in a quartz fixed bed reactor with an internal diameter of 8 mm, and the reactants were 0.5 volume% of methane, 0.25 volume% of oxygen (O / C = 1.0), 1.9 volume% of water (S / C = 2.8), and nitrogen was used as the balance gas. It was. The volume of the reaction gas was supplied at 50 ml / min. At this time, the catalyst layer was diluted with 1 g of alpha alumina 100/120 mesh to ensure temperature uniformity of the catalyst layer. In addition, the concentration of methane was kept very low (0.5% by volume) to eliminate temperature nonuniformity due to the heat of reaction. The charged catalyst was cooled to the reaction temperature after reduction pretreatment with 10% H ₂ / N ₂ gas at 600 ° C. for 1 hour, and then proceeded with the reaction. The conversion of methane was measured 3 hours after the reaction feed to reach steady state. Methane conversion was determined using Equation 1 below. The conversion of oxygen was also determined in the same way as methane.

[Equation 1]

The concentrations of hydrogen and carbon monoxide in the catalyst bed exhaust gas were quantified using 1 vol% of standard gas. They were analyzed using Hewlett-Packard's HP-6890 gas chromatography equipped with a thermal conductivity detector (TCD) detector and a flame ionization detector (FID). Hydrogen, oxygen, and carbon monoxide were separated into a molecular sieve 13X, and methane was separated into an HP-1 capillary column (30 m, ID 250 μm), and gaseous chromatography used helium. The activity of the catalyst was measured at 400 ° C to 700 ° C.

As a result of the activity measurement, the methane conversion rate is summarized in FIG. 3, and the concentrations of hydrogen, carbon monoxide and oxygen conversion rates generated are summarized in Table 1.

Single catalyst activity according to Preparation Example 1 was measured under the same conditions as in Example 1. However, the catalyst was used by diluting 0.1g single component of Rh-Mg / Al ₂ O ₃ to 1g of alpha alumina (Aldrich, 34,265-3).

TABLE 1

Reactant Conversion and Product Concentration According to Examples 1 and 2

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As a result of the experiment, the conversion rate of methane is as shown in FIG. 3, and the conversion rate of oxygen, the production concentrations of hydrogen and carbon monoxide are summarized in Table 1 above. The single catalyst showed somewhat lower activity than the mixed catalyst. However, it was found that the high temperature activity was high while the low temperature activity below 500 ° C. was lower than that of the second catalyst alone (Pt / YSZ) activity according to Comparative Example 1.

Example 3

The activity of Rh [0.1] -Mg / Mg-Al ₂ O ₃ catalyst according to Preparation Example 3 was measured under the same conditions as in Example 1.

Experimental results are summarized in Figure 4 and Table 2. Compared with the Rh / Mg-Al ₂ O ₃ catalyst of Comparative Example 2 prepared not to include an alkaline earth metal, superior activity could be obtained.

TABLE 2

Reactant Conversion and Product Concentration According to Example 3

 Item  catalyst  Reaction temperature (℃) Reactant                                          product                                           Etc   Example 3 Single Catalyst (Rh [0.1] -Mg / Mg-Al ₂ O ₃ 0.05g) CH ₄ % Conversion O ₂ conversion rate (%) H ₂ concentration (%) CO concentration (%) 400 0.3 0.8 0 0 Pretreatment 10% H ₂ / N ₂ . 1 hours 500 2.9 12.2 0 0 600 100 100 1.58 0.11 650 99.6 100 1.55 0.13

Example 4

The methane conversion rate of the catalyst prepared in Preparation Example 1 was measured in the same manner as in Example 1 without any pretreatment. However, after the catalyst was heated at a rate of 1 ° C./min from 400 ° C. to 600 ° C. without pretreatment with hydrogen, the conversion rate of methane and the concentration of the generated gas were measured along the cooling process at a rate of −1 ° C./min.

Experimental results, as shown in FIG. 5, Table 3 showed a large difference in the methane conversion rate in the heating and cooling of the catalyst bed. The methane conversion rate shown in the cooling process is similar to that of Example 1 (FIG. 3, A), which is reduced by using hydrogen, and is activated in the high temperature portion and is determined to be maintained until the low temperature portion. In this respect, it can be seen that the pretreatment of the catalyst has a great effect on the activity.

TABLE 3 Reactant conversion and product concentration according to Example 4

Example 5

The activity of the catalyst was measured in the same manner as in Example 4 with respect to the mixed catalyst according to Example 1.

Experimental results As shown in FIG. 6 and Table 4, the same results were obtained in the heating process and the cooling process despite the condition that the separate pretreatment was not performed. In this regard, it can be seen that a high conversion rate can be obtained from a low temperature without pretreatment of the catalyst when the second group of Pt / YSZ catalysts are mixed and used. Therefore, it is evaluated as a catalyst composition which can minimize the process simplification and the reactor volume.

TABLE 4

Reactant Conversion and Product Concentration According to Example 5

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Example 6

As a mixed catalyst according to the first group, 0.025 g of the Rh-Mg / Al ₂ O ₃ catalyst according to Preparation Example 1 and 0.025 g of the Pt-Mg / YSZ catalyst according to Preparation Example 5 were mixed, and in the same manner as in Example 1 The activity of the catalyst was measured.

As a result of the experiment, as shown in FIG. 7 and Table 5, the activity of the catalyst according to Example 6, in which the catalysts of the first group and the second group were mixed, was compared with the respective catalysts. Could.

TABLE 5

Reactant Conversion and Product Concentration According to Example 6

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Example 7

As a catalyst according to the first group, activity against 0.05 g of the Pt-Mg / YSZ catalyst prepared in Preparation Example 5 was measured in the same manner as in Example 1.

As a result of the experiment, as shown in FIG. 7 and Table 6, the activity of the catalyst according to Example 6 in which the catalysts of the first group and the second group were mixed was compared to the respective catalysts. Could.

TABLE 6

Reactant Conversion and Product Concentration According to Example 7

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Example 8

The activity of the mixed catalyst of the second group was measured. 0.025 g of Rh / Al ₂ O ₃ according to Preparation Example 2 and 0.025 g of Pt / YSZ according to Preparation Example 6 were mixed and used in the same manner as in Example 1.

As a result, as shown in FIG. 8 and Table 7, it was shown that the same conversion rate can be obtained at a low temperature of 150 ° C. compared with Comparative Example 3 using the Rh / Al ₂ O ₃ single catalyst. Compared to the second group homocatalyst, the reactivity was weak at low temperatures (400-425 ° C.) compared to the first and second group mixed catalysts.

TABLE 7

Reactant Conversion and Product Concentration According to Example 8

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Example 9

Reaction temperature for a mixed catalyst of 0.025 g of catalyst Rh [0.2] -Mg [3] / Al ₂ O ₃ according to Preparation Example 1 and Pt / YSZ 0.025 g according to Preparation Example 6 as catalyst of Group 2 Experiments were carried out at the following four conditions at 700 ℃ to measure the methane conversion, carbon monoxide, hydrogen production stability of each reaction condition. At this time, the reaction was analyzed as in Example 1.

1 (Section A): Maintain 30 vol% of methane, 15 vol% of oxygen (O / C = 1.0), nitrogen balance gas and no water supply (S / C = 0.0) for 6 hours.

2 (section B): supply water to the reactants of the condition 1 S / C = 1.8, the air supply was stopped to change to O / C = 0.0 to maintain for 10 hours.

3 (Section C): Add an air supply in the reactant of the condition 2, and maintained for 3 hours by changing to O / C = 0.0, S / C = 2.5 conditions.

4 (section D): Changed to condition 1 above. At this time, reduce the air supply and maintain O / C = 0.7.

As a result of activity measurement, as shown in FIG. 10, the methane conversion rate and the concentration of hydrogen and carbon monoxide were constant during the reaction. The highest methane conversion was obtained under reaction condition 3, in which both air and moisture were supplied. From these results, the method of operating the catalytic reactor in the form of supplying only hydrocarbons and air for the purpose of initial start-up of the reactor is also evaluated as a usable catalyst. In addition, it is evaluated as a catalyst system that is resistant to coke generation even if the supply conditions of water and air supplied to the reactor are uneven. In particular, it is evaluated as a catalyst system that ensures stability even if O / C, S / C ratio nonuniformity occurs depending on the operating state of the reactor or the dispersion state of the reactants.

Comparative Example 1

As a catalyst according to Preparation Example 6, the activity of Pt / YSZ catalyst, which is known as a catalyst for partial oxidation reaction, was measured.

The experiment was conducted in the same manner as in Example 2. However, the catalyst was replaced with Pt / YSZ.

As a result of the experiment, as shown in FIG. 3 and Table 8, the conversion to methane at low temperature was high, but the reaction temperature had to be raised to 600 ° C. in order to obtain a high conversion of more than 95%. That is, it is evaluated as a result demonstrating that the configuration of the mixed catalyst according to the present invention is very effective.

TABLE 8

Reactant Conversion and Product Concentration According to Comparative Example 1

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Comparative Example 2

The experiment was conducted in the same manner as in Comparative Example 1. However, the catalyst was replaced with Rh / Mg-Al ₂ O ₃ according to Preparation Example 4.

As shown in FIG. 4 and Table 9, the conversion rate of methane was very low over the entire temperature range. In particular, it exhibited very poor activity compared to catalysts prepared to contain alkaline earth metals (Example 3). That is, the alkaline earth metal as the first group catalyst component according to the present invention is evaluated as a result demonstrating that it is very important to co-precipitate with the precious metal at the same time.

TABLE 9

Reactant Conversion and Product Concentration According to Comparative Example 2

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Comparative Example 3

The experiment was conducted in the same manner as in Comparative Example 1. However, the catalyst was replaced with Rh / Al ₂ O ₃ according to Preparation Example 2.

As a result of the experiment, as shown in FIG. 8 and Table 10, compared to the catalyst mixed with Pt / YSZ, the temperature at which the same conversion rate can be obtained is increased by 180 degrees. From these results, it can be seen that it is very effective when constructing the mixed catalyst according to the present invention.

TABLE 10

Reactant Conversion and Product Concentration According to Comparative Example 3

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Comparative Example 4

The activity of the catalyst supporting the precious metal on the same support as the catalyst supported on the catalyst of the first and second groups, respectively, was compared. The activity of the Pt-Rh-Mg / Al ₂ O ₃ catalyst according to Preparation Example 7 was measured as in Example 1. It was used without the catalyst pretreatment.

As shown in FIG. 9 and Table 11, the low temperature activity was lower than that of the mixed catalyst according to Example 1. Accordingly, it can be seen that even in the case of a catalyst using the same precious metal, it is possible to improve the low temperature activity when using the separated mixed catalyst according to the present invention rather than a catalyst simultaneously supported on the same support.

TABLE 11

Reactant Conversion and Product Concentration According to Comparative Example 4

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In the case of using the catalyst of the present invention, the reaction start temperature is lowered and at the same time, a separate activation process is not required, and the configuration simplification and start-up time of the syngas production process can be significantly reduced.

Claims (15)

0.01-15% by weight of at least one precious metal selected from the group consisting of Rh, Ru, Pd and Pt and 0.1-15% by weight of at least one alkaline earth metal selected from Group 2A on the periodic table, based on the weight of the first group catalyst support Is a first group catalyst prepared by supporting a porous support composed of at least one material selected from the group consisting of Al, Si, Zr, Ti, Ba, Ce, Co, Mg, La, Y and their oxides or oxides thereof ; And 0.01 to 10.0 wt% of at least one precious metal selected from the group consisting of Rh, Ru, Pd, and Pt based on the weight of the Group 2 catalyst support: Al, Si, Zr, Ti, Ba, Ce, Co, Mg, La And a second group catalyst prepared by supporting at least one porous support selected from the group consisting of Y and oxides thereof, wherein the second group catalyst is 0.1 to 49% of the total weight of the catalyst. A high activity catalyst for syngas production. delete delete At least one precious metal selected from the group consisting of Rh, Ru, Pd and Pt and at least one alkaline earth metal selected from Group 2A on the periodic table are Al, Si, Zr, Ti, Ba, Ce, Co, Mg, La, Y And a first group catalyst prepared by supporting a porous support composed of at least one material selected from the group consisting of oxides or oxides thereof. And at least one porous metal selected from the group consisting of Al, Si, Zr, Ti, Ba, Ce, Co, Mg, La, Y, and oxides thereof, and at least one precious metal selected from the group consisting of Rh, Ru, Pd and Pt. Uniformly pulverizing and mixing the second group catalyst prepared on the support so that the content of the second group catalyst is 0.1 to 49% of the total weight of the catalyst; And Processing the mixed catalyst into a granular or monolithic material or coating it onto a metal plate, metal mesh or metal web Method for producing a high activity catalyst for syngas production, characterized in that it comprises a. The method of claim 4, wherein the first group catalyst and the second group catalyst are uniformly ground and mixed to 10 µm or less. delete delete A process for producing a syngas comprising reforming a reactant comprising at least one of hydrocarbons and alcohols, water and air by passing through a catalyst bed according to claim 1. The process of claim 8, wherein the hydrocarbon is selected from the group consisting of aliphatic hydrocarbons having 1 to 32 carbons, aromatic hydrocarbons, and olefins. 10. The process according to claim 9, wherein the hydrocarbon is selected from the group consisting of methane, ethane, propane, butane gas phase and petroleum, gasoline, and gaseous hydrocarbons. The process of claim 8, wherein the alcohol is methanol, ethanol or a mixture thereof. The process of claim 8, wherein the temperature of the catalyst layer is 400-900 ° C., and the gas space velocity (GHSV) of the reactants is 2,000-400,000 ^{hr −1} . 9. The process of claim 8, wherein the reactant comprises 0.01 to 4.5 times the oxygen relative to the molar ratio of the carbon in the hydrocarbon and 0.01 to 3.5 times the steam in the molar ratio of the carbon in the hydrocarbon. The process of claim 8, wherein steam is supplied after heating the temperature of the reactor to a range of 500 ° C. to 1000 ° C. using hydrocarbon combustion heat when the reactor is started. The process of claim 8, wherein the heating of the reactor is heated to a range of 500 to 1000 ° C. by using combustion heat of hydrocarbons when starting the reactor, and then the supply of air is stopped and steam is supplied.

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