KR102186052B1 - Catalyst Comprising MgO-Al2O3 Hybrid Support and The Method of Preparing Synthesis Gas from Carbon Dioxide Reforming of Acetone Using the Same - Google Patents

Abstract

The present invention relates to copper on a support comprising magnesium oxide and alumina, transition metals such as nickel, cobalt, iron, manganese, chromium, zirconium, tungsten, lanthanum, such as lanthanum, cerium, gadolinium, and platinum, ruthenium, rhodium, and Acetone and carbon dioxide reforming catalyst carrying a metal active component including at least one element selected from platinum group elements such as palladium, and a method for producing syngas containing carbon monoxide and hydrogen from carbon dioxide reforming reaction of acetone using the same About.

Description

Catalyst Comprising MgO-Al2O3 Hybrid Support and The Method of Preparing Synthesis Gas from Carbon Dioxide Reforming of Acetone Using the Same}

The present invention relates to a catalyst for reforming carbon dioxide in which a metal active ingredient is supported on a support including magnesium oxide and alumina, and a method for producing a synthesis gas from a carbon dioxide reforming reaction of acetone using the same.

Synthetic gas has conventionally been produced by gasification of coal, steam reforming of hydrocarbons using natural gas or the like, or partial oxidation reforming. However, in the gasification method of coal, there is a problem that not only a complex and expensive coal gasification furnace is required, but also a large-scale plant is used. In addition, in the steam reforming method of hydrocarbons, since the reaction involves a large endothermic, a high temperature of about 700 to 1200°C is required for the progress of the reaction, and a special reforming furnace is required, as well as high heat resistance for the catalyst used. There were problems such as this required. In addition, in the partial oxidation and reforming of hydrocarbons, since high temperatures are required, a special partial oxidation furnace is required, and a large amount of soot is generated according to the reaction, so that treatment is not only a problem, but the catalyst is deteriorated. There was a problem such as easy to become.

Meanwhile, amid global warming, greenhouse gas reduction plans are being announced in countries around the world, and the burden on the industry is increasing as the Korean government has set the greenhouse gas reduction target at 30% of the 2020 emission forecast.

The problem is that the energy efficiency level of domestic companies is already the best in the world, so the capacity to reduce greenhouse gases is limited. In addition, if the government regulates as a means of reduction, there are concerns about production disruptions caused by companies moving their factories abroad or rising costs. As an alternative, the present invention focuses not on reducing carbon dioxide emissions, but on the use of carbon dioxide emitted as a resource.

One of the many ways to turn carbon dioxide into a resource is to produce synthetic gas through acetone reforming reaction using carbon dioxide. Such a reforming reaction of acetone using carbon dioxide becomes a means to effectively remove carbon dioxide, which is the cause of global warming, and as a result, it is not only used as a raw material gas for methanol synthesis, oxo synthesis, Fischer Tropsch synthesis, etc., but also ammonia synthesis or various Synthetic gas, which can be widely used as a raw material for chemical products, can be produced.

In addition, since the reforming reaction of acetone using carbon dioxide can produce a synthesis gas having a very high carbon monoxide content (H ₂ : CO = 1: 1.6) according to the following Scheme 1, the generated synthesis gas is oxoacetone (oxoalcohol) and dimethyl ether. (dimethyl ether, DME), polycarbonate (PC), acetic acid, etc. It is widely used as a reactant in the production process of high value-added chemical products, as well as ammonia synthesis or raw materials for various chemical products. .

CH ₃ COCH ₃ + 2CO ₂ → 3H ₂ + 5CO (Scheme 1)

However, in the carbon dioxide reforming reaction of acetone, since catalyst deactivation by carbon deposition occurs severely, an expensive catalyst containing noble metals such as rhodium and ruthenium, which does not cause a significant problem of carbon deposition, can exhibit high activity and long life. However, noble metal catalysts have a higher resistance to carbon deposition than nickel catalysts, have good activity, but are expensive, so they are unsuitable for industrial use.

In order to solve the above problems, development of a catalyst capable of reducing production cost so as to facilitate industrial use while minimizing carbon deposition in the reforming reaction of acetone using carbon dioxide has been continuously attempted.

As an example, Japanese Patent Publication No. 4,398,670 (2009.10.30) discloses that (a) at least one component selected from a ruthenium component, a platinum component, a rhodium component, a palladium component, and an iridium component, and (b) cobalt Component and/or (c) a method of producing hydrogen or synthetic gas by carbon dioxide reforming an oxygen-containing hydrocarbon using a catalyst formed by supporting at least one component selected from an alkali metal component, an alkaline earth metal component and a rare earth metal component As, the composite catalyst system is excellent in durability and exhibits catalytic properties with greatly improved activity (Patent Document 1).

In addition, Korean Laid-Open Patent Publication No. 10-2009-0115709 (2009.11.05) contains copper as an essential element, has at least one element selected from nickel, cobalt, and platinum group elements, and uses a catalyst system that exists as a composite metal oxide. Thus, it relates to a method for efficiently producing hydrogen or synthetic gas from an oxygen-containing hydrocarbon with a high conversion rate, wherein the composite metal oxide has a feature of having high durability by having an active metal including nickel, cobalt or platinum group (Patent Document 2).

However, Patent Document 1 is still unsuitable for industrial use as it essentially contains expensive active metals including noble metals such as rhodium and ruthenium, and in Patent Document 2, using a complex oxide catalyst system that does not contain noble metals. Although an example of producing a syngas from the reforming reaction of carbon dioxide has been disclosed, the reaction yield of the syngas produced from the reforming of carbon dioxide with acetone by using these catalysts is not specifically mentioned.

As mentioned above, it is still necessary to develop a technology for producing syngas with a high conversion rate in the carbon dioxide reforming reaction of acetone using a complex catalyst system that does not contain expensive active metals.

Therefore, by using a catalyst in which a nickel active metal is supported on a magnesium-alumina composite support (MgO-Al ₂ O ₃ ) containing magnesium having a similar atomic radius as nickel, a synthesis gas having a high conversion rate from the carbon dioxide reforming reaction of acetone The present invention was completed by confirming that it can be manufactured.

Japanese Patent Publication No. 4,398,670 (2009.10.30) Korean Patent Publication No. 10-2009-0115709 (2009.11.05)

In order to solve the above problems, the present researchers completed the present invention while researching and developing a catalyst technology for carbon dioxide reforming reaction of acetone.

The purpose of this destruction is to provide a technology for producing syngas with high conversion rate from carbon dioxide reforming reaction of acetone by using a catalyst in which nickel (Ni) is supported on a magnesium-alumina composite support (MgO-Al ₂ O ₃ ). To do.

In order to solve the above problems, the present invention is made of copper, nickel, cobalt, iron, manganese, chromium, zirconium, tungsten, lanthanum, cerium, gadolinium, platinum, ruthenium, rhodium, and palladium on a support comprising magnesium oxide and alumina. Producing a synthetic gas containing carbon monoxide and hydrogen from a reforming reaction of a mixed gas containing acetone and carbon dioxide, characterized in that it comprises a composite composition supported with a metal active ingredient containing at least one element selected from the group consisting of It provides a catalyst for carbon dioxide reforming reaction of acetone for.

In another embodiment of the present invention, the support may contain magnesium oxide in the range of 20 to 50 wt%.

In addition, in the catalyst system, the metal active component may include nickel as an essential element, and the metal active component may be included in the range of 2 to 20 wt% with respect to the support.

In another embodiment of the present invention, the support may be prepared through pretreatment of firing at a predetermined temperature, and the pretreatment of the support is 1 to 10 hours at a temperature of 600 to 900°C in an atmosphere of air or inert gas. Can be carried out during.

In addition, the present invention provides a method of producing a synthesis gas containing carbon monoxide and hydrogen from a reforming reaction of a reactant containing acetone and carbon dioxide.

In this case, a diluent is added to the catalyst for carbon dioxide reforming reaction of acetone, and the diluent may be silicon carbide (SiC).

In addition, in the carbon dioxide reforming reaction of acetone, carbon dioxide may be added in the range of 50 to 200 mol% with respect to acetone, the reaction temperature may be carried out in the range of 650 to 850 °C, and the space velocity of the reactant including acetone and carbon dioxide May range from 6000 to 18000 h ^-1 .

The catalyst according to the present invention has the advantage that the conversion rate of carbon dioxide in the carbon dioxide reforming reaction of acetone is much higher than that of a general catalyst system, so that the utilization of carbon dioxide can be greatly increased, and thus the greenhouse gas reduction effect can be improved.

In particular, by pretreating the support, there is an effect of greatly enhancing catalytic activity even at a relatively low temperature.

1 is a result of the conversion rate of carbon dioxide measured at each temperature of 700°C, 750°C, 800°C, and 850°C in the carbon dioxide reforming reaction of acetone of the complex catalysts prepared according to Examples 1 to 3 and Comparative Examples 1 to 5 .
2 is a result of measuring the x-ray diffraction (XRD) analysis of the composite catalysts prepared according to Examples 1 to 3 and Comparative Examples 1 to 5 after (a) firing and after (b) reduction.
3 is a result of measuring the temperature-reduction (Temperatur-programmed reduction, TPR) of the composite catalyst prepared according to Examples 1 to 3 and Comparative Examples 1 to 5.

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration of the present invention, including a preferred embodiment by which one of ordinary skill in the art can easily implement the present invention. In describing the principles of the preferred embodiments of the present invention in detail, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

The present invention provides a method for producing a synthesis gas containing carbon monoxide and hydrogen from a carbon dioxide reforming reaction of acetone using a carbon dioxide reforming catalyst, wherein the catalyst for carbon dioxide reforming includes copper on a support including magnesium oxide and alumina, Metals containing at least one element selected from transition metals such as nickel, cobalt, iron, manganese, chromium, zirconium, tungsten, lanthanums such as lanthanum, cerium, gadolinium, and platinum group elements such as platinum, ruthenium, rhodium and palladium It is characterized in that it comprises a composite composition loaded with the active ingredient.

The catalyst for carbon dioxide reforming of the present invention includes a composite composition in which at least one metal active ingredient is supported on a magnesium oxide/alumina support, and the acid-base characteristics of the alumina support are improved by including a magnesium oxide component having basic properties in the support. It can be adjusted to enhance the activity in the modification reaction.

At this time, the magnesium oxide/alumina support (MgO/Al ₂ O ₃ ) used as a support in the carbon dioxide reforming catalyst is a mixture of magnesium oxide and alumina, and the magnesium oxide is 20 to 50 wt% of the magnesium oxide/alumina support. It is preferable to be included in the range, and if the magnesium oxide is less than 20 wt%, the effect of increasing the dispersibility of the metal active ingredient on the magnesium oxide/alumina support is not sufficient, and the reaction yield decreases, and the magnesium oxide is When it exceeds 50 wt%, as the pores of the alumina catalyst support are filled with magnesium oxide, the specific surface area and the pore volume decrease, resulting in a problem that the activity of the catalyst decreases.

In addition, the catalyst for carbon dioxide reforming may include copper, nickel, cobalt, iron, manganese, chromium, zirconium, tungsten and other transition metals, lanthanum, cerium, gadolinium, etc. on a magnesium oxide/alumina support (MgO/Al ₂ O ₃ ). It is preferable that a metal active component including at least one element selected from lanthanum and platinum group elements such as platinum, ruthenium, rhodium and palladium is supported.

In addition, the carbon dioxide reforming catalyst preferably contains a metal active component in the range of 2 to 30 wt% with respect to the support, and when the metal active component is less than 2 wt%, sufficient catalytic activity does not appear, and the metal active component is 20 wt%. When it exceeds %, it is uneconomical in terms of increasing the catalytic activity effect according to the catalyst content, and as the particle size of the active metal increases, the activity of the catalyst decreases, which is undesirable.

In addition, the catalyst for reforming carbon dioxide may include nickel as an essential element as a metal active component.

The nickel metal active ingredient may be prepared from a nickel compound, as a nickel compound Ni(NO ₃ ) ₂ , NiSO ₄ , NiCl ₂ , Ni(OH) ₂ , Ni(CH ₃ COO) ₂ , Ni ₃ H ₂ (CO ₃ ) ₄ , NiCO ₃ and the like may be used, but are not limited thereto. These compounds may be used alone or in combination of two or more, preferably Ni(NO ₃ ) ₂ Can be used.

In addition, in preparing the catalyst for carbon dioxide reforming according to the present invention, a method of supporting a metal active ingredient on a magnesium oxide/alumina support (MgO/Al ₂ O ₃ ) is a generally known method, i.e., coprecipitation, precipitation. Deposition method, sol-gel method, melting method, impregnation method, etc. can be used. In particular, it is active to support a metal active component on a magnesium oxide/alumina support (MgO/Al ₂ O ₃ ) using an impregnation method. It is preferable in terms of increasing the.

The nickel precursor solution obtained by dissolving the nickel precursor in deionized water or an alcoholic solvent is impregnated with a magnesium oxide-alumina or alumina support, dried and fired to be prepared from nickel/magnesium oxide-alumina or nickel/alumina whose nickel is modified on the surface. I can.

Specifically, the amount of the solvent used in the impregnation method is not particularly limited, and after measuring the pore volume of alumina, the solution may be loaded by the same volume, and the excess solution may be dried after impregnating an excess solution.

In addition, the composite including the magnesium oxide/alumina support (MgO/Al ₂ O ₃ ) on which the metal compound prepared by the impregnation method is supported is the magnesium oxide on which the metal active component in the oxidized state is supported through a drying process and a firing process. /Alumina support (MgO/Al ₂ O ₃ ) It is possible to prepare a composite containing.

The drying process may be performed at 100 to 130° C. for 10 to 20 hours, and the drying process is not particularly limited, and a rotary evaporator or oven may be used, and the solvent in the composite may be removed through the drying process. Can be removed.

The firing process may be performed at 600 to 900° C. for 3 to 10 hours, and through the firing process, organic substances in the metal compound as a precursor of the metal active component are removed, and a composite containing the metal active component in an oxidized state is formed. Can be manufactured.

In addition, the metal active component can be converted to a reduced state by performing a reduction reaction of the complex including the magnesium oxide/alumina support (MgO/Al ₂ O ₃ ) supported by the metal active component in an atmosphere of hydrogen and argon thereafter, and the reduction The reaction is preferably carried out immediately before the carbon dioxide reforming reaction after charging the catalyst in the reactor.

In addition, the particle size of the metal active ingredient supported on the magnesium oxide/alumina support (MgO/Al ₂ O ₃ ) is preferably 10 nm or less, and the smaller the particle size of the metal active ingredient, the more metal active site is. As it increases, it has excellent performance as a catalyst.

In addition, in supporting the active metal, the support may not be pretreated, but the active metal may be supported, and the active metal may be supported after pretreatment of the support through firing in advance.

In the pretreatment, the support may be calcined at a temperature of 600 to 900°C, preferably 750 to 850°C in an atmosphere such as air or inert gas. At this time, it is appropriate to maintain the temperature increase rate of 1 to 20° C./min, preferably 1 to 5° C./min, and may be baked for 1 to 10 hours, preferably 3 to 6 hours.

Specifically, in the present invention, the carbon dioxide reforming reaction of acetone may use a mixture containing acetone and carbon dioxide as a reactant, and in this case, the carbon dioxide reforming reaction of acetone proceeds as shown in Scheme 1 below. At this time, synthesis gas (H ₂ : CO = 1: 1.6) having a relatively high carbon monoxide content can be prepared from the carbon dioxide reforming reaction of acetone.

CH ₃ COCH ₃ + 2CO ₂ → 3H ₂ + 5CO (Scheme 1)

In the carbon dioxide reforming reaction of acetone, a fixed bed reactor equipped with an external heating system is used as the reactor.

The catalyst for carbon dioxide reforming according to the present invention was molded and pulverized to have a particle size of 250 to 600 µm, and then filled in the reactor together with a diluent in the required amount.

It is preferable to use silicon carbide (SiC) as the diluent, and the diluent serves to disperse high heat generated during the reaction in the reactor.

In addition, a mixture containing acetone and carbon dioxide as a reactant in a molar ratio of 1:0.5 to 2 was injected into the reactor, and nitrogen was added as a diluting gas. At this time, the temperature of the reactor is controlled in the range of 650 ~ 850 ℃ by the control device, the reaction pressure is normal pressure, and the flow rate of the gas is adjusted so that the space velocity is 6000 ~ 18000 h ^-1 by injecting gas to continuously react. By doing so, it is possible to manufacture a syngas.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments. However, these examples are for explaining the present invention in more detail, and it will be apparent to those of ordinary skill in the art that the scope of the present invention is not limited thereto.

Magnesium oxide-modified alumina support used in Examples and Comparative Examples of the present invention MgO-Al ₂ O ₃ (Product made by SASOL) used 30 wt%MgO-70 wt%Al ₂ O ₃ , which was designated as MgO-Al ₂ O ₃ without any other indication. In addition, in the notation of the catalyst, -pre. Addition to cal. indicates that the support was fired at 800° C. for 5 hours at a heating rate of 2° C./min. For example, MgO-Al ₂ O ₃ -pre. Indicated as cal. means that 30 wt%MgO-70 wt%Al ₂ O ₃ was fired at 800° C. for 5 hours at a heating rate of 2° C./min.

An alumina support was used a commercially available alumina (Sasol, tablet, a specific surface area of ^{-210 m 2 / g), SiO} 2 is _{Sigma Aldrich, CeO 2 Alfa Aeser,} ZrO 2 was used for items purchased from Alfa Aeser.

Examples 1 to 3 and Comparative Examples 1 to 5

4.9 g of nickel nitrate salt (Ni(NO ₃ ) ₂ ·6H ₂ O) as a catalyst active ingredient was supported on 10 g of the support as described in the table. In Example 3, a nickel precursor solution was prepared by dissolving in 30 ml of deionized water in Examples 1 and 2 and Comparative Example 1-5, and then supported on the support by an impregnation method. The support impregnated with the nickel precursor solution was dried at 100° C. for 12 hours and calcined at 800° C. for 5 hours in an air atmosphere to prepare a catalyst primary molded body.

At this time, the addition of -pre-cal. means that Ni is supported using a support prepared by firing the support before Ni is supported at 800°C for 5 hours at a heating rate of 2°C/min. In addition, the addition of -WI means that the active metal was prepared by the Incipient Wetness Method in the manufacture of the catalyst, and the addition of -WI means that the catalyst was impregnated with an excessive amount of solvent. The active metal was supported by impregnation.

Subsequently, the prepared catalysts were subjected to reduction treatment in an atmosphere of hydrogen and argon, and then the crystal characteristics and surface area of the catalyst were measured, and are shown in Tables 1 and 2 below.

As a result of XRD analysis of the composite catalysts according to Examples 1 to 3 and Comparative Examples 1 to 5, a characteristic peak of the used support was observed. From this, it can be seen that the crystal structure of the support is maintained even during the manufacturing process of the catalyst.

The catalysts according to Examples 1 to 3 show that the crystal size of nickel (Ni) in a reduced state is smaller than that of the catalysts according to Comparative Examples 1 to 2 that do not contain magnesium in the support, and in particular, it is prepared by firing the support in advance. The catalyst according to Example 2 has the smallest metal size and an average pore size of 15.39 nm, so it is predicted that the flow of reactants and products will proceed efficiently.

In addition, as shown in FIG. 3, in the case of the catalysts according to Examples 1 to 3 and Comparative Examples 1 to 2, reduction occurs actively around 800°C, and in the case of the catalyst according to Comparative Examples 3 to 5, the reduction of bulk NiO The peak by is observed in the 200-450 ^o C region. That is, it can be seen that a difference occurs in the interaction between the active metal and the support according to the type of the support.

Experimental Example 1: Carbon dioxide reforming reaction of acetone

Prepare the catalysts according to Examples 1 to 3 and Comparative Examples 1 to 5 so that the average particle size is 250-600 μm, and 0.5 ml of the catalyst and 0.5 ml of diluent (SiC) are filled using quartz wool I did.

The reactor used for the carbon dioxide reforming reaction of acetone is a fixed bed reactor equipped with an external heating system, and is a quartz tubular reactor with an outer diameter of 1/2 inch. The liquid reducing agent of acetone was injected into the reactor through a vaporizer set to 120 ^° C, and the gas lines before and after the reactor were maintained at a temperature of 120 ^° C.

Before the reaction, the prepared catalyst was reduced with 5% H ₂ -Ar at 850° C. for 1 hour, and the temperature was adjusted at a heating rate of 5 ^° C/min to reach the reduction temperature.

A reaction gas consisting of acetone and carbon dioxide was supplied into the reactor at a space velocity of 200 cm ³ /min (SV=12,000h ^{- 1} ) to perform a catalytic reaction. The gas used in each reaction was supplied in a stoichiometric ratio according to the following reaction equation.

Table 2 and FIG. 1 show the conversion rates of CO ₂ at each reaction temperature in the carbon dioxide reforming reaction of acetone. Conversion of the CO ₂ was calculated after the reaction in the initial CO ₂ concentration divided by the initial concentration of CO ₂ to remove the concentration of CO _2.

The conversion rate of carbon dioxide in the carbon dioxide reforming reaction of acetone using the catalyst according to Examples 1 to 3 was much higher than the conversion rate of carbon dioxide in the carbon dioxide reforming reaction of acetone using the catalyst according to Comparative Examples 1 to 5. Particularly, in the case of Example 2 in which the support was fired in advance, the highest conversion rate was shown, and the conversion rate at 700°C, which is a relatively low reaction temperature, was 76.7%, showing superior activity compared to other catalyst systems.

As described above, the present invention has been described with reference to the accompanying drawings and embodiments, but these are only exemplary, and those of ordinary skill in the field belonging to the art can use various modifications and equivalent other embodiments therefrom. I will understand. Therefore, the technical protection scope of the present invention should be determined by the following claims.

Claims (11)

As a catalyst for carbon dioxide reforming reaction of acetone,
One or more elements selected from the group consisting of nickel, copper, cobalt, iron, manganese, chromium, zirconium, tungsten, lanthanum, cerium, gadolinium, platinum, ruthenium, rhodium and palladium on a support comprising magnesium oxide and alumina Comprising a composite composition on which a metal active ingredient is supported,
The support is characterized in that it is prepared through pretreatment of sintering magnesium oxide and alumina in the oxide state at a predetermined temperature before the metal active component is supported,
A catalyst for reforming carbon dioxide of acetone for producing syngas containing carbon monoxide and hydrogen from a reforming reaction of a mixed gas containing acetone and carbon dioxide.
The method of claim 1,
The support is a catalyst for carbon dioxide reforming reaction of acetone, characterized in that the magnesium oxide is contained in the range of 20 to 50 wt%.
The method of claim 1,
The catalyst is a catalyst for reforming carbon dioxide of acetone, characterized in that the metal active component contains nickel as an essential element.
The method of claim 1,
The catalyst is a catalyst for carbon dioxide reforming reaction of acetone, characterized in that the metal active component is contained in the range of 2 to 20 wt% with respect to the support.
delete The method of claim 1,
The pretreatment of the support is carried out for 1 to 10 hours at a temperature of 600 to 900°C in an atmosphere of air or inert gas.
In the presence of the catalyst according to any one of claims 1 to 4 and 6,
A method of producing a syngas containing carbon monoxide and hydrogen by performing a reforming reaction of a reactant containing acetone and carbon dioxide.
The method of claim 7,
A diluent is added to the catalyst for carbon dioxide reforming reaction of acetone,
The method for producing a syngas, characterized in that the diluent is silicon carbide (SiC).
The method of claim 7,
The carbon dioxide reforming reaction of acetone is a method of producing a synthesis gas, characterized in that the reaction is carried out by adding carbon dioxide in a range of 50 to 200 mol% with respect to acetone.
The method of claim 7,
The temperature of the reforming reaction is a method for producing a synthesis gas, characterized in that the range of 650 ~ 850 ℃.
The method of claim 7,
In the reforming reaction, the space velocity of the reactant including acetone and carbon dioxide is in the range of 6000 to 18000 h ^-1 .

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