KR102616015B1 - Catalyst for Methane Chlorination Reaction in Which a Graphtic Carbon Based Material is Highly Dispersed in an Inorganic Matrix - Google Patents

Abstract

The present invention relates to a catalyst for methane chlorination reaction, and more specifically, compared to catalysts for methane chlorination reaction using existing carbon-based materials, it has excellent mechanical properties without the use of a binder and has high activity for methane chlorination reaction, resulting in high yield. It relates to a catalyst for methane chlorination reaction that can produce methane chloride.

Description

Catalyst for Methane Chlorination Reaction in Which a Graphtic Carbon Based Material is Highly Dispersed in an Inorganic Matrix}

The present invention relates to a catalyst for methane chlorination reaction, and more specifically, to a catalyst for methane chlorination reaction in which a crystalline graphical carbon-based material is highly dispersed in an inorganic matrix.

The importance of research on ways to utilize natural gas, which is abundant in reserves around the world, is increasing, and attempts have been made mainly on thermal decomposition reactions using oxygen of methane in natural gas and coupling reactions using catalysts. In particular, in order to utilize methane, the main component of natural gas, chlorine and methane are reacted to produce methyl chloride, and this methyl chloride is converted into commercially useful compounds such as ethylene and/or propylene through the CMTO (chloromethane to olefin) reaction. Research is being actively conducted on methods for producing light olefins.

As a method of chlorinating methane, an oxychlorination reaction process in which the chlorination reaction is carried out in the presence of oxygen is usually performed, but the oxychlorination reaction is generally used for mass production of carbon oxides or dimers. As a result, the selectivity of methane becomes low. In addition, oxychlorination of methane is generally accompanied by the production of unexpected chlorinated methane by-products, and the production process is overly complicated due to the application of reaction conditions that include air.

Meanwhile, chlorine gas produced through the chloralkali process is widely used in building materials, electrical and electronic materials, biotechnology, pharmaceuticals, and aviation materials through various chlorination processes, but excessive chlorine is generated more than necessary. Or, in the case of unreacted chlorine, problems with its disposal arise. Chlorine gas is highly toxic and has the property of easily corroding metals and other materials when in contact with moisture. Although chlorine gas itself does not catch fire, it is a strong oxidizing gas that causes a violent combustion reaction in the event of a fire. In particular, when a leak occurs, it combines with moisture in the air to produce hydrochloric acid, which causes strong corrosion on the surfaces of equipment and pipes. It can cause damage to the human body, such as burns and pulmonary edema, when contacting or inhaling chlorine gas. Therefore, it is necessary to treat the chlorine generated in the process. This is becoming a major challenge in process operation.

Accordingly, the process of producing methane chloride by chlorinating methane has great advantages not only in terms of methane utilization but also in terms of chlorine consumption.

As a conventional technology related to the chlorination of methane, Korean Patent No. 10-0105571 describes a method of converting methane in gas using a catalyst carrying transition metal compounds such as platinum, ruthenium, and rhodium in a carrier such as alumina, zeolite, and silicate. In U.S. Patent No. 10329226, a process for producing chlorinated methane using a support containing alumina, silica, and activated carbon and a catalyst carrying metals, metal oxides, and metal halides on the support has been disclosed.

However, the catalysts not only increase catalyst manufacturing costs by using expensive noble metal compounds, but also have the problem of requiring a separate process to treat the wastewater because wastewater is inevitably generated during the catalyst manufacturing process.

Accordingly, in Korean Patent No. 2223601, the present inventors have disclosed a catalyst for methane chlorination reaction using a carbon-based material that is cheaper than existing catalysts and has high activity in the methane chlorination reaction. The catalyst used has a low surface area and does not aggregate well, so it is difficult to form a high-strength catalyst using general molding methods such as extruding and tableting. In order to obtain a high-strength molded catalyst, it is molded with a carbon-based binder at a high temperature. In the case of doing so, there was still a low surface area compared to the weight of the molded body, making it difficult to actually commercialize and scale up the methane chlorination process.

Therefore, there is a need to develop a catalyst that can not only convert methane into useful substances in the methane chlorination process, but also can be commercialized and scaled up while maximizing the conversion rate of chlorine.

Korean Patent No. 10-0105571 (Announcement Date: 1996.04.25.) U.S. Patent No. 10329226 (Publication date: 2018.09.13.) Korean Patent No. 10-2223601 (Announcement date: 2021.03.05.)

The main purpose of the present invention is to solve the above-mentioned problems. Compared to catalysts for methane chlorination reaction using existing carbon-based materials, no special molding process is required, and it has excellent mechanical properties and has high activity for methane chlorination reaction. The aim is to provide a catalyst for a methane chlorination reaction capable of producing methane chloride in high yield and a method for producing the catalyst for the methane chlorination reaction.

In addition, the purpose of the present invention is to provide a method for producing methane chloride, characterized in that methane chloride is produced by chlorinating a methane-containing reactant with chlorine under oxygen-free conditions using the catalyst for the methane chlorination reaction.

In order to achieve the above object, one embodiment of the present invention is a catalyst for methane chlorination reaction under oxygen-free conditions, wherein the catalyst is a crystalline graphitic carbon-based material evenly dispersed in an inorganic matrix, A catalyst for methane chlorination reaction is provided, wherein the strength is 15 N or more, and the crystalline graphitic carbon-based material in the catalyst is 10% to 40% by weight based on the total weight of the catalyst.

In a preferred embodiment of the present invention, the inorganic matrix may be characterized as being derived from pseudo-boehmite.

In a preferred embodiment of the present invention, the catalyst for methane chlorination reaction may be characterized as having a mesopore volume of 0.2 cm ³ /g to 0.9 cm ³ /g.

Another embodiment of the present invention is a method for producing a catalyst for a methane chlorination reaction that chlorinates methane under oxygen-free conditions, (a) mixing an inorganic matrix precursor and a crystalline graphitic carbon-based material with a solvent to make a paste. Obtaining; (b) forming a catalyst precursor to a predetermined size by applying pressure to the obtained dough; and (c) calcining the catalyst precursor to prepare a catalyst, wherein the crystalline graphitic carbon-based material in the catalyst prepared after the calcining is 10 wt% to 40 wt% based on the total weight of the catalyst. A method for producing a catalyst for methane chlorination reaction is provided.

In another preferred embodiment of the present invention, the solvent in step (a) is mixed in an amount of 30 to 100 parts by weight based on 100 parts by weight of the inorganic matrix precursor and the crystalline graphitic carbon-based material. You can.

In another preferred embodiment of the present invention, step (b) may be characterized in that the catalyst precursor is formed by extruding the dough using an extruder and cutting it into a predetermined size.

In another preferred embodiment of the present invention, the calcination temperature in step (c) may be 450°C to 750°C.

In another preferred embodiment of the present invention, step (a) further comprises 2 to 7 parts by weight of a plasticizer based on 100 parts by weight of the inorganic matrix precursor and the crystalline graphitic carbon-based material. You can do this.

In another preferred embodiment of the present invention, the plasticizer is at least one selected from the group consisting of methyl cellulose, polyvinyl alcohol (PVA), and polyethylene glycol (PEG). can do.

Another embodiment of the present invention provides a method for producing methane chloride, characterized in that methane chloride is produced by chlorinating a methane-containing reactant with chlorine under oxygen-free conditions.

In another preferred embodiment of the present invention, the reaction temperature for the chlorination of methane is 100°C to 600°C, the reaction pressure is 0 barg to 30 barg, and the molar ratio of methane to chlorine is 1/20 to 20/1, The gas hourly space velocity (GHSV) of the reactants may be characterized as 100 cc/g/h or more.

The catalyst for methane chlorination reaction according to the present invention is formed by evenly dispersing a crystalline graphical carbon-based material in an inorganic material matrix with porosity and high strength characteristics, which serves as a matrix, and has excellent mechanical properties, reducing reaction efficiency even after long-term operation. At the same time, it has high activity in the methane chlorination reaction even with a small content of carbon-based materials, making it possible to produce methane chloride in high yield, and the shape of the catalyst can be formed arbitrarily without using a separate molding aid. It can be usefully applied in the actual commercialization and scale up of the methane chlorination process.

Figure 1 is a graph of Cl ₂ conversion rate, CH ₄ conversion rate, and CH ₃ Cl selectivity results measured using catalysts prepared in Examples 1 to 3 and Comparative Examples 1 to 3 of the present invention.
Figure 1 is a graph of Cl ₂ conversion rate, CH ₄ conversion rate, and CH ₃ Cl selectivity results measured using catalysts prepared in Examples 1 and 4 and Comparative Examples 4 to 6 of the present invention.

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various different forms. These embodiments only serve to ensure that the disclosure of the present invention is complete and that common knowledge in the technical field to which the present invention pertains is not limited. It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims.

In describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

When 'includes', 'has', 'consists of', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, the plural is included unless specifically stated otherwise.

Also, in the case of a description of a positional relationship, for example, if the positional relationship between two parts is described as 'on top', 'on the top', 'on the bottom', 'next to', etc., 'right away' Unless ' or 'directly' is used, one or more other parts may be placed between the two parts. In the case of a description of a temporal relationship, for example, if a temporal relationship is described as ‘after’, ‘after’, ‘after’, ‘before’, etc., ‘immediately’ or ‘directly’ Non-consecutive cases may also be included unless ' is used.

Each feature of the various embodiments of the present invention can be combined or combined with each other, partially or entirely, and various technical interconnections and operations are possible, and each embodiment can be implemented independently of each other or together in a related relationship. It may be possible.

The present invention relates to a catalyst for the chlorination reaction of methane, a method of producing the catalyst for the chlorination reaction of methane, and a method of chlorinating a reactant containing methane with chlorine under anoxic conditions using the catalyst.

Generally, the methane chlorination reaction occurs at the interface between the reactant and the catalyst, so it is necessary to increase the area of the interface. However, in the case of crystalline carbon-based materials that are inexpensive and have high activity for the methane chlorination reaction, the specific surface area is small; Because they do not stick together well, it has been difficult to produce high-strength commercial catalysts using general methods. In addition, even when molding at high temperature using a binder to manufacture a high-strength commercial catalyst, the specific surface area compared to the weight of the catalyst molded body is small, making it difficult to manufacture a commercial catalyst showing high activity in the methane chlorination reaction.

Accordingly, in the present invention, a catalyst for the chlorination reaction of methane is manufactured by evenly dispersing a crystalline graphitic carbon-based material at a specific content in a specific inorganic matrix with porosity and high strength characteristics, thereby providing excellent mechanical properties and using a special binder. It was confirmed that a molded catalyst of any shape can be easily formed even with a small amount of carbon-based material, and that methane chloride can be produced in high yield with high activity for the methane chlorination reaction even with a small amount of carbon-based material. led to invention.

The crystalline graphitic carbon-based material is a material that exhibits catalytic activity for methane chlorination reaction, and may be a carbon-based material containing a graphite structure and may include graphite oxide. The graphite oxide means that graphite, which has a layered structure in which carbon atoms bonded by sp2 bonds are oxidized and given an oxygen-containing functional group, is provided by oxidizing graphite ore, carbonizing an organometallic complex in an inert gas, or It can be obtained by oxidizing graphene. At this time, it is preferable that 5% or more of sp2 carbon in the graphite-like carbon body is contained in the structure.

The crystalline graphitic carbon-based material used in the present invention refers to carbon-based materials in the form of graphite and is not particularly limited, and various graphite materials such as general natural graphite, artificial graphite, or pyrolytic graphite can be employed. there is. Additionally, various graphite materials processed into spherical shapes through a general processing process (crushing process, spheroid forming process, etc.) may be used, for example, flaky graphite may be used.

The crystallinity of the crystalline graphitic carbon-based material may vary depending on the type or production method, as cited in previously filed Korean Patent No. 2223601, and the performance as a catalyst may vary due to the difference in crystallinity. You can.

The crystallinity of the crystalline graphitic carbon-based material according to the present invention can be expressed by the Raman peak intensity ratio (I _D / I _G Ratio), and the Raman peak intensity ratio of the crystalline graphitic carbon-based material ( I _D /I _G Ratio) may be 0.05 to 0.130, preferably 0.05 to 0.125. Crystalline graphitic carbon-based materials satisfying the Raman peak intensity ratio in the above range can exhibit particularly high performance in methane chlorination reactions.

In addition, the crystalline graphitic carbon-based material in the present invention has a specific surface area of 10 m ² /g or more, and the crystalline graphitic carbon-based material satisfying the specific surface area in the above range is capable of performing a methane chlorination reaction. The conversion rate of chlorine can be shown to be high.

Meanwhile, the crystalline graphitic carbon-based material can be used as is, but can be used by treating the surface with a functional group or by supporting a transition metal active in the methane chlorination reaction.

The functional group is optionally an arene group, ter-butyl group, cyclohexyl group, hydroxyl group, lactone group, lactam group, ester group, amide group, imine group, amino group, imide group, azide group, nitrile group, nitroxy group, Nitro group, nitroso group, pyridine group, phosphine group, phosphoric acid group, phosphonic acid group, sulfonic group, sulfonic acid group, sulfoxide group, thiol group, sulfate group, sulfide group, carbonyl group, aldehyde group, carboxyl group, carboxylate group, haloformyl group. , ether group, peroxy group, hydroperoxy group, acyl halide group, fluoro group, chloro group, bromo group and iodine group.

There is no particular limitation on the method of functionalizing the crystalline graphitic carbon-based material with the above-mentioned functional group as long as it is within the scope of achieving the purpose of the present invention.

The transition metals may be those known to be active in methane chlorination reaction, and are preferably ruthenium (Ru), platinum (Pt), rhodium (Rh), cobalt (Co), nickel (Ni), and palladium (Pd). It includes, but is not limited to, at least one selected from the group consisting of.

The transition metal content may be 20% by weight or less, preferably 0.5% by weight to 10% by weight, based on the total weight of the crystalline graphic carbon-based material. If the metal content exceeds 20% by weight, it is not preferable because there is a problem in that sufficient chlorination reaction efficiency cannot be obtained compared to the content of the crystalline graphic carbon-based material.

The crystalline graphitic carbon-based material may be evenly dispersed in an inorganic matrix described later at 10% to 40% by weight based on the total weight of the catalyst. If the crystalline graphitic carbon-based material is included in less than 10% by weight based on the total weight of the catalyst, a problem of reduced methane chlorination reaction activity may occur due to a lack of catalytic active material, and 40% by weight If the % is exceeded, the catalyst strength may become very low due to the property of the carbon-based material used as the catalytically active material not to agglomerate well.

The inorganic matrix is a material that supports the crystalline graphitic carbon-based material, strengthens the strength of the catalyst, increases wear resistance, and provides the specific surface area of the catalyst. It is a material with a large specific surface area and excellent mechanical strength. It may be, and preferably may be pseudo-boehmite.

The catalyst according to the present invention in which a crystalline graphitic carbon-based material is dispersed in the inorganic matrix has an apparent density of 0.4 g/cm ³ to 0.7 g/cm ^{3 .} If it exceeds this, a problem may arise in which the catalyst activity may be lowered due to the use of a large amount of an inorganic matrix or an inorganic matrix with small mesopores, and if the apparent density of the catalyst is less than 0.4 g/cm ³ , crystalline graphitic If a large amount of carbon-based material is contained or a large amount of a porous inorganic matrix is used, a problem may occur in which the catalyst strength may be lowered.

In addition, the catalyst according to the present invention may have a mesopore volume of 0.2 cm ³ /g ~ 0.9 cm ³ /g, preferably 0.25 cm ³ /g ~ 0.6 cm ³ /g, and a strength of 15 N. It may be an inorganic substance.

If the mesopore volume of the catalyst is less than 0.2 cm ³ /g, the methane chlorination reaction activity may be reduced due to lack of mesoporosity, and if it exceeds 0.9 cm ³ /g, the methane chlorination reaction activity may decrease. A problem may occur in which catalyst strength is reduced due to excessive pores in the inorganic matrix.

Additionally, if the strength of the catalyst is less than 15 N, the catalyst may be damaged due to the low strength, dust may be generated during this process, and the pressure drop in the reactor may increase.

The catalyst for methane chlorination reaction according to the present invention includes the steps of (a) mixing an inorganic matrix precursor and a crystalline graphitic carbon-based material with a solvent to obtain a paste; (b) forming a catalyst precursor to a predetermined size by applying pressure to the obtained dough; and (c) calcining the formed catalyst precursor to prepare a catalyst.

In the method for producing a catalyst for methane chlorination reaction according to the present invention, a paste is first obtained by mixing an inorganic matrix precursor and a crystalline graphitic carbon-based material with a solvent [step (a)].

The crystalline graphitic carbon-based material may be the graphite-type carbon-based material described above, and the inorganic matrix precursor includes beohmite, pseudo-boehmite, and diaspor. ), gibbsite, bayerite, and nordstrandite, and may preferably be pseudo-boehmite.

At this time, the weight ratio of the crystalline graphic carbon-based material and the inorganic matrix precursor may be 1:1.5 to 10. If the weight ratio of the inorganic matrix precursor to the crystalline graphic carbon-based material is less than 1.5, a problem may occur in which the strength of the catalyst is reduced due to the property of carbon, which is the catalytically active material, not to agglomerate easily. If it is exceeded, the amount of catalytically active material decreases, which may cause a problem in which the methane chlorination reaction activity decreases.

The solvent is prepared into a paste by mixing 30 to 100 parts by weight of the inorganic matrix precursor and 100 parts by weight of the crystalline graphitic carbon-based material. If less than 30 parts by weight of solvent is mixed per 100 parts by weight of the inorganic matrix precursor and crystalline graphitic carbon-based material, the dough becomes hard, so when trying to inject the catalyst before firing into a predetermined shape. Problems may arise in which injection is not performed smoothly, and if the amount exceeds 100 parts by weight, the dough becomes soft, making it difficult to form it into a desired shape.

As the solvent, water (distilled water), alcohols, ether ketones, aromatics, etc. can be used, and water (distilled water), alcohols, or a mixture of water and alcohols are particularly preferable.

In addition, in step (a), a dough can be obtained by additionally adding a plasticizer when mixing the inorganic matrix precursor and the crystalline graphitic carbon-based material with a solvent.

The plasticizer plays a role in increasing the plasticity of dough mixed with an inorganic matrix precursor and a crystalline graphitic carbon-based material, and types include methyl cellulose and polyvinyl alcohol (PVA). and polyethylene glycol (PEG), and preferably methyl cellulose in terms of mechanical properties.

The plasticizer may be included in an amount of 2 to 7 parts by weight, preferably 2 to 6 parts by weight, based on 100 parts by weight of the inorganic matrix precursor and the crystalline graphitic carbon-based material. If the content of the plasticizer is less than 2 parts by weight based on 100 parts by weight of the inorganic matrix precursor and the crystalline graphitic carbon-based material, a problem of reduced plasticity may occur due to lack of elasticity and flexibility. If it exceeds 7 parts by weight, the plasticizer is decomposed during the calcination process. During this process, the plasticizer present between the catalysts is decomposed, which may cause excessive pores to be formed and weaken the strength of the catalyst.

The dough obtained in this way is pressured to form a catalyst precursor of a predetermined size [step (b)].

For the formation of the catalyst precursor, known devices such as tablet presses, extruders, and electric granulators can be used, but it is preferable to use high pressure devices that are relatively inexpensive compared to expensive devices that require high pressure, such as tablet presses or tumbling granulators. You can use an extruder that does not require this.

The extruder includes a screw type and a batch type extruder, and the screw type extruder capable of continuous operation is mainly used. The screw extruder can cut the catalyst precursor discharged while inputting and extruding the dough into a predetermined size to have a constant size. At this time, there are no particular restrictions on the shape or size of the catalyst precursor, but it is usually formed in a spherical shape, columnar shape, cylindrical shape, star shape, etc., and the size of the catalyst precursor can be easily adjusted depending on the scale of the applied device or the concentration of reactants, etc. It can be used effectively.

Afterwards, the catalyst precursor is calcined to prepare a catalyst [step (c)]. The firing can be performed at 450°C to 750°C for 3 to 6 hours.

When the sintering temperature is less than 450°C or less than 3 hours, components such as plasticizers remain without thermal decomposition, and the inorganic matrix precursor is not completely converted to the inorganic phase, so mesopores are not formed, and the sintering temperature is 750°C. If it exceeds or exceeds 6 hours, a problem may occur in which catalytic activity decreases due to a decrease in mesopores and surface area of the inorganic matrix due to excessive heat treatment.

In addition, before the calcination, impurities such as solvents contained in the catalyst precursor may be removed and drying may be performed to smoothly proceed with the calcination described later. The drying can be performed without limitation as long as the temperature and time are sufficient to remove water, and is preferably performed at 110°C to 120°C for 12 to 24 hours.

The present invention provides a methane chlorination method for producing methane chloride through chlorination reaction of methane (CH ₄ )-containing reactant with chlorine (Cl ₂ ) under oxygen-free conditions in the presence of the catalyst for methane chlorination reaction described above.

In the chlorination method of methane, reaction temperature and pressure, molar ratio of methane-containing reactants to chlorine, and gas hourly space velocity (GHSV) of the reactants can be process variables for the reaction.

In the method for chlorination of methane, the reaction temperature may be 100°C to 600°C, preferably 200°C to 500°C, more preferably 250°C to 350°C, and even more preferably 300°C to 350°C.

If the reaction temperature is less than 100°C, the conversion rate of methane may be minimal, and if it is above 600°C, catalyst deactivation may occur as the reaction progresses, which is not desirable.

Additionally, in the chlorination reaction, the molar ratio of methane-containing reactant to chlorine may be 1/20 to 20/1. Preferably, the molar ratio may be 1/10 to 15/1, more preferably 1/5 to 10/1, and most preferably 1/1 to 5/1.

In the chlorination reaction, if the molar ratio of methane-containing reactant to chlorine is less than 1/20 or more than 20/1, reaction efficiency may decrease and the burden of a separate separation process due to unreacted products may greatly increase, which is not preferable.

In the method for chlorination of methane, the gas hourly space velocity (GHSV) of the reactants may be at least 100 cc/g/h, preferably at least 1,000 cc/g/h, and more preferably at least 2,000 cc/g/h. . The upper limit of the gas time space velocity (GHSV) can be determined and used by a person skilled in the art depending on the reactor design and the shape of the catalyst. Without limitation, the upper limit may be 500,000 cc/g/h.

If the gas time space velocity (GHSV) of the reactants is less than 100 cc/g/h, the size of the reactor is too large compared to the throughput of the reactor, which may lead to a problem of low efficiency, which is not desirable.

In the methane chlorination method, the reaction pressure can be varied in the range of 0 barg to 30 barg. Preferably, the reaction pressure may be 0 barg to 20 barg, more preferably 0 barg to 10 barg, and most preferably 0 barg to 5 barg.

If the reaction pressure is less than 0 barg, additional equipment to maintain vacuum is required and the degree of reaction decreases, and even if it exceeds 30 barg, the equipment for maintaining the pressure becomes expensive and operating costs increase excessively. There is.

In the methane chlorination method, the methane-containing reactant and chlorine may be diluted with a diluent to perform the chlorination reaction. The diluent may preferably be at least one selected from the group consisting of helium, argon, and nitrogen, but is not limited thereto. In addition, the diluent may be preferably used in a molar ratio of 2:1 or more with respect to chlorine, that is, the diluent may be used in a molar ratio of 2 or more times that of chlorine, but is not limited to this. In addition, the present invention relates to a method for producing methane chloride, using any one of the catalysts described above, and producing methane chloride through chlorination reaction of methane-containing reactants with chlorine under oxygen-free conditions. provides.

Hereinafter, the present invention will be described in more detail through specific examples. The following examples are merely examples to aid understanding of the present invention, and the scope of the present invention is not limited thereto.

<Example 1>

As shown in Table 1, 171 g of sudo-boehmite, 30 g of graphite, and 4.5 g of methylcellulose (PMB-4OH) were mixed with 100 g of distilled water to obtain a dough, and the obtained dough was put into an extruder to have a diameter of A pellet-shaped catalyst precursor measuring 1.9 mm was formed. The catalyst precursor was dried at 100°C for 12 hours and then calcined at 450°C for 3 hours to prepare a catalyst containing 20 wt% of graphite based on the total weight of the catalyst.

<Example 2>

As shown in Table 1, 109.4 g of sudo-boehmite, 33 g of graphite, and 4.2 g of methylcellulose (PMB-4OH) were mixed with 70 g of distilled water to obtain a dough, and the obtained dough was put into an extruder to have a diameter of A pellet-shaped catalyst precursor measuring 1.9 mm was formed. The catalyst precursor was dried at 100°C for 12 hours and then calcined at 450°C for 4 hours to prepare a catalyst containing 30 wt% of graphite based on the total weight of the catalyst.

<Example 3>

As shown in Table 1, 50 g of sudo-boehmite, 23.4 g of graphite, and 3.9 g of methylcellulose (PMB-4OH) were mixed with 70 g of distilled water to obtain a dough, and the obtained dough was put into an extruder to have a diameter of A pellet-shaped catalyst precursor measuring 1.9 mm was formed. The catalyst precursor was dried at 100°C for 12 hours and then calcined at 450°C for 4 hours to prepare a catalyst containing 40 wt% of graphite based on the total weight of the catalyst.

<Example 4>

As shown in Table 1, 171 g of sudo-boehmite, 30 g of graphite, and 4.5 g of polyvinyl alcohol (PVA) were mixed with 110 g of distilled water to obtain a dough, and the obtained dough was put into an extruder to have a diameter of 1.9. A pellet-shaped catalyst precursor with a diameter of mm was formed. The catalyst precursor was dried at 100°C for 12 hours and then calcined at 450°C for 4 hours to prepare a catalyst containing 20 wt% of graphite based on the total weight of the catalyst.

<Comparative Example 1>

As shown in Table 1, 64.88 g of silica sol (Ludox AS-40), 100 g of graphite, 6.25 g of kaolin, and 6.25 g of methylcellulose (PMB-4OH) were mixed with 90 g of distilled water to obtain a dough. The obtained dough was put into an extruder to form a pellet-shaped catalyst precursor with a diameter of 1.9 mm. The catalyst precursor was dried at 100°C for 12 hours and then calcined at 450°C for 4 hours to prepare a catalyst containing 80 wt% of graphite based on the total weight of the catalyst.

<Comparative Example 2>

As shown in Table 1, 12 g of Alumina Sol (AS-520), 60 g of graphite, 12 g of Kaolin, and 1.8 g of methylcellulose (PMB-4OH) were mixed with 190 g of distilled water to obtain a dough. Then, the obtained dough was put into an extruder to form a pellet-shaped catalyst precursor with a diameter of 1.9 mm. The catalyst precursor was dried at 100°C for 12 hours and then calcined at 450°C for 4 hours to prepare a catalyst containing 80.5 wt% of graphite based on the total weight of the catalyst.

<Comparative Example 3>

As shown in Table 1, 57.1 g of sudo-boehmite, 40 g of graphite, and 5.1 g of methylcellulose (PMB-4OH) were mixed with 75 g of distilled water to obtain a dough, and the obtained dough was put into an extruder to have a diameter of A pellet-shaped catalyst precursor measuring 1.9 mm was formed. The catalyst precursor was dried at 100°C for 12 hours and then calcined at 450°C for 4 hours to prepare a catalyst containing 50 wt% of graphite based on the total weight of the catalyst.

<Comparative Example 4>

As shown in Table 1, 42 g of fumed silica (Aerosil 380), 10 g of graphite, and 1.5 g of methylcellulose (PMB-4OH) were mixed with 130 g of distilled water to obtain a dough, and the obtained dough was placed in an extruder. was added to form a pellet-shaped catalyst precursor with a diameter of 1.9 mm. The catalyst precursor was dried at 100°C for 12 hours and then calcined at 450°C for 4 hours to prepare a catalyst containing 20 wt% of graphite based on the total weight of the catalyst.

<Comparative Example 5>

As shown in Table 1, 80 g of Kaofine, 20 g of graphite, and 3 g of methylcellulose (PMB-4OH) were mixed with 90 g of distilled water to obtain a dough, and the obtained dough was put into an extruder to obtain a diameter. A pellet-shaped catalyst precursor measuring 1.9 mm was formed. The catalyst precursor was dried at 100°C for 12 hours and then calcined at 450°C for 4 hours to prepare a catalyst containing 20 wt% of graphite based on the total weight of the catalyst.

<Comparative Example 6>

As shown in Table 1, 171 g of sudo-boehmite, 30 g of graphite, and 4.5 g of polyethylene glycol (PEG) were mixed with 70 g of distilled water to obtain a dough, and the obtained dough was put into an extruder to have a diameter of 1.9 mm. A catalyst precursor in the shape of a phosphorus pellet was formed. The catalyst precursor was dried at 100°C for 12 hours and then calcined at 450°C for 4 hours to prepare a catalyst containing 20 wt% of graphite based on the total weight of the catalyst.

division crystalline graphic
Carbon-based material (A) Inorganic Matrix Precursor (B) plasticizer type content
(wt%) type content
(wt%) type Parts by weight per 100 parts by weight of A and B Example 1 black smoke 20 Capital - Bohemite 80 PMB-40H 2.2 Example 2 black smoke 30 Capital - Bohemite 70 PMB-40H 3.0 Example 3 black smoke 40 Capital - Bohemite 60 PMB-40H 4.0 Example 4 black smoke 20 Capital - Bohemite 80 PVA 2.2 Comparative Example 1 black smoke 80 Silica sol/kaolin 20 PMB-40H 4.0 Comparative Example 2 black smoke 80.5 Alumina sol/kaolin 19.5 PMB-40H 2.0 Comparative Example 3 black smoke 50 Capital - Bohemite 50 PMB-40H 5.0 Comparative Example 4 black smoke 20 fumed silica 80 PMB-40H 2.8 Comparative Example 5 black smoke 20 Kao Pine 80 PMB-40H 2.9 Comparative Example 6 black smoke 20 Capital - Bohemite 80 PEG 2.2

<Experimental Example 1: Measurement of catalyst properties>

The specific surface area, total pore volume, and mesopore volume of the catalysts prepared in Examples and Comparative Examples were measured using a BET measuring device (TriStar II 3020, Micromeritics, USA), and the results are shown in Table 2. Degassing was performed at 300°C for 5 hours, and nitrogen physical adsorption was performed at -196°C. The surface area was calculated using the BET model, and the pore size was calculated using the BJH model.

Catalyst type Surface area ( ^m2 /g) Total Pore Volume ( ^cm3 /g) Mesopore Volume (cm ³ /g) Example 1 342 0.48 0.38 Example 2 294 0.40 0.31 Comparative Example 1 54 0.18 0.16 Comparative Example 4 285 1.08 0.99 Comparative Example 5 26 0.11 0.10

As shown in Table 2, the catalysts prepared in Examples 1 and 2 had a specific surface area of 294 m ² /g or more, a total pore volume of 0.40 cm ³ /g or more, and a mesopore volume of 0.31 cm ³ /g. ~ 0.38 cm ³ /g, while for the catalysts prepared in Comparative Examples 1, 4 and 5, the specific surface area was 285 m ² /g or less, and the total pore volume was 0.18 cm ³ /g or less or 1.08 cm ³ /g. and the mesopore volume was found to be 0.16 cm ³ /g or less or 0.99 cm ³ /g.

<Experimental Example 2: Measurement of mechanical properties of catalyst>

Bulk density was measured by adding a certain amount of the catalyst prepared in Examples 1 to 4 and Comparative Examples 1 to 6 into a measuring cylinder and measuring its height. In addition, the compressive strength is measured by placing the catalysts prepared in Examples 1 to 4 and Comparative Examples 1 to 6 on a jig using a compressive strength measuring device, and measuring the compressive strength until the plate attached to the measuring device is lowered and the catalyst is compressed and broken. The compressive strength of the catalyst was measured and the results are shown in Table 3.

Catalyst type Bulk density (B.D.) Compressive strength (N) Example 1 0.60 40.2 Example 2 0.55 23.2 Example 3 0.58 18.6 Example 4 0.43 16.5 Comparative Example 1 0.38 1.3 Comparative Example 2 0.38 1.2 Comparative Example 3 0.44 4.2 Comparative Example 4 0.27 10 Comparative Example 5 0.56 14.4 Comparative Example 6 0.45 5.5

As shown in Table 3, for the catalysts prepared in Examples 1 to 4, the compressive strength was 15 N or more, whereas for the catalysts prepared in Comparative Examples 1 to 6, the compressive strength was 14.4 N or less, Comparative Example 1 It was confirmed that the catalysts of Examples 1 to 4 were superior to the catalysts of Examples 1 to 6 in terms of compressive strength.

<Experimental Example 3: Performance measurement for methane chlorination reaction according to the content of crystalline graphic carbon-based material>

The catalysts and γ-alumina prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were pretreated at 400°C under a nitrogen atmosphere, and then 2 g of the pretreated catalyst was placed in a fixed-bed reactor (Inconel tube reactor, length 450 mm). , inner diameter of 11 mm), and the performance of the methane-chlorination reaction was measured while flowing reactants containing methane and chlorine. An atmosphere for methane chlorination reaction was created under oxygen-free conditions, and the reaction was carried out by injecting methane and chlorine gas diluted with helium, a diluent, into the reactor (injected molar ratio: CH ₄ /Cl ₂ /He=1/1/2). did. The path of chlorine gas within the reactor was shielded from light, and the product of the chlorination reaction was analyzed using GC-FID (GC using a HP PLOT-Q capillary column and a flame ionization detector, gas chromatography).

The reaction time for analyzing the conversion rate of chlorine gas and the selectivity of the product (chloride of methane) by the chlorination reaction is generally 1 hour, the molar ratio of CH ₄ /Cl ₂ is 3:1, and the GHSV of the reactant is It is 2,000 cc/g/h, the reaction temperature is 350 ℃, and the reaction pressure is normal pressure. The measured conversion, selectivity and yield are shown in Table 4 and Figure 1.

division Catalyst type CH ₄ conversion rate _Cl2 conversion rate CH ₃ Cl selectivity (%) CH ₃ Cl yield (%) Experimental Example 3-1 Example 1 25.8 100 68.60 17.7 Experimental Example 3-2 Example 2 23.9 96.8 67.60 16.2 Experimental Example 3-3 Example 3 24.2 96.9 69.30 16.8 Comparative Experiment Example 3-1 Comparative Example 1 24.3 100 62.70 15.2 Comparative Experiment Example 3-2 Comparative Example 2 28.2 100 64.00 18.0 Comparative Experiment Example 3-3 Comparative Example 3 25.7 100 66.10 17.0 Comparative Experiment Example 3-4 - 18.1 70.4 73.4 13.3 Comparative Experiment Example 3-5 γ-alumina 19.63 82.09 68.44 13.4

As shown in Table 4 and Figure 1, in the case of Experimental Examples 3-1 to 3-3 using the catalysts of Examples 1 to 3, Comparative Experimental Examples 3-4 without using a catalyst and Comparative Experiments using γ-alumina as a catalyst Compared to Examples 3-5, the conversion rates of CH ₄ and Cl ₂ and the selectivity and yield of CH ₃ Cl were found to be significantly superior. In particular, in the case of the catalysts prepared in Examples 1 and 3, despite the small content of graphite, the catalysts in Comparative Examples It was found that the conversion rates of CH ₄ and Cl ₂ and the selectivity and yield of CH ₃ Cl were excellent compared to the catalyst prepared in .

<Experimental Example 4: Performance measurement for methane chlorination reaction according to plasticizer and inorganic matrix precursor type>

The catalysts prepared in Examples 1 and 4 and Comparative Examples 4 to 6 were pretreated at 400°C under a nitrogen atmosphere, and then 2 g of the pretreated catalyst was placed in a fixed-bed reactor (Inconel tube reactor, length 450 mm, internal diameter 11 mm). ) were filled in each and the performance of the methane-chlorination reaction was measured while flowing reactants containing methane and chlorine. An atmosphere for methane chlorination reaction was created under oxygen-free conditions, and the reaction was carried out by injecting methane and chlorine gas diluted with helium, a diluent, into the reactor (injected molar ratio: CH ₄ /Cl ₂ /He=1/1/2). did. The path of chlorine gas within the reactor was shielded from light, and the product of the chlorination reaction was analyzed using GC-FID (GC using a HP PLOT-Q capillary column and a flame ionization detector, gas chromatography).

The reaction time for analyzing the conversion rate of chlorine gas and the selectivity of the product (chloride of methane) by the chlorination reaction is generally 1 hour, the molar ratio of CH ₄ /Cl ₂ is 3:1, and the GHSV of the reactant is It is 2,000 cc/g/h, the reaction temperature is 350 ℃, and the reaction pressure is normal pressure. The measured conversion, selectivity and yield are shown in Table 5 and Figure 2.

division Catalyst type CH ₄ conversion rate _Cl2 conversion rate CH ₃ Cl selectivity (%) CH ₃ Cl yield (%) Experimental Example 4-1 Example 1 25.8 100 68.60 17.7 Experimental Example 4-2 Example 4 21.65 87.39 69.05 14.9 Comparative Experiment Example 4-1 Comparative Example 4 21.77 93.98 64.19 14.0 Comparative Experiment Example 4-2 Comparative Example 5 21.59 87.28 70.01 15.1 Comparative Experiment Example 4-3 Comparative Example 6 22.29 90.66 68.17 15.2 Comparative Experiment Example 4-4 - 18.1 70.4 73.4 13.3

As shown in Table 5 and Figure 2, in the case of Experimental Examples 4-1 and 4-2 using the catalysts of Examples 1 and 4, Comparative Experimental Examples 4-4 and Comparative Experimental Examples 4-1 to 4 without using a catalyst Compared to -3, the conversion rate of CH ₄ and Cl ₂ and CH ₃ Cl selectivity and yield were found to be higher, and especially in the case of Experiment 4-1 using the catalyst of Example 1, despite the small content of graphite, the Compared to Experimental Examples 4-1 to 4-3 using a catalyst, conversion rates of CH ₄ and Cl ₂ and CH ₃ Cl selectivity and yield were found to be excellent.

Therefore, the catalyst for methane chlorination reaction according to the present invention has excellent mechanical properties, so that reaction efficiency does not decrease even after long-term operation, and at the same time, it has high activity for methane chlorination reaction even with a small content of carbon-based materials, producing methane chloride in high yield. It was confirmed that it could be manufactured.

The present invention has been described above with reference to the accompanying drawings and examples, but these are merely illustrative, and those skilled in the art will recognize that various modifications and other equivalent embodiments are possible therefrom. You will understand. Therefore, the scope of technical protection of the present invention should be determined by the claims below.

Claims (11)

In the catalyst for methane chlorination reaction under oxygen-free conditions,
The catalyst is a crystalline graphitic carbon-based material evenly dispersed in an inorganic matrix, and has a strength of 15 N or more. The crystalline graphitic carbon-based material in the catalyst is 10 N based on the total weight of the catalyst. Catalyst for methane chlorination reaction, characterized in that it is 40% by weight.
According to paragraph 1,
A catalyst for methane chlorination reaction, wherein the inorganic matrix is derived from pseudo-boehmite.
According to paragraph 1,
The catalyst for methane chlorination reaction is characterized in that the mesopore volume is 0.2 cm ³ /g to 0.9 cm ³ /g.
In the method for producing a catalyst for a methane chlorination reaction that chlorinates methane under oxygen-free conditions,
(a) mixing an inorganic matrix precursor and a crystalline graphitic carbon-based material with a solvent to obtain a paste;
(b) forming a catalyst precursor to a predetermined size by applying pressure to the obtained dough; and
(c) calcining the formed catalyst precursor to prepare a catalyst;
A method for producing a catalyst for methane chlorination reaction, characterized in that in the catalyst prepared after the firing, the crystalline graphitic carbon-based material is 10 wt% to 40 wt% based on the total weight of the catalyst.
According to paragraph 4,
A method for producing a catalyst for methane chlorination reaction, characterized in that the solvent in step (a) is mixed in an amount of 30 to 100 parts by weight based on 100 parts by weight of the inorganic matrix precursor and the crystalline graphitic carbon-based material.
According to paragraph 4,
The step (b) is a method of producing a catalyst for methane chlorination reaction, characterized in that the dough is extruded using an extruder and cut to a predetermined size to form a catalyst precursor.
According to paragraph 4,
A method for producing a catalyst for methane chlorination reaction, characterized in that the calcination temperature in step (c) is 450 ℃ ~ 750 ℃.
According to paragraph 4,
The step (a) is a method for producing a catalyst for methane chlorination reaction, characterized in that it further comprises 2 to 7 parts by weight of a plasticizer based on 100 parts by weight of the crystalline graphitic carbon-based material.
According to clause 8,
A method for producing a catalyst for methane chlorination reaction, wherein the plasticizer is at least one selected from the group consisting of methyl cellulose, polyvinyl alcohol (PVA), and polyethylene glycol (PEG). .
Using the catalyst of any one of claims 1 to 3,
A method for producing methane chloride, characterized in that methane chloride is produced by chlorinating a methane-containing reactant with chlorine under oxygen-free conditions.
According to clause 10,
The chlorination reaction temperature of methane is 100 ℃ ~ 600 ℃, the reaction pressure is 0 barg ~ 30 barg, the molar ratio of methane to chlorine is 1/20 ~ 20/1, and the gas time space velocity (GHSV) of the reactants is A method for producing methane chloride, characterized in that is 100 cc/g/h or more.