KR101862683B1

KR101862683B1 - Preparation of Metal Oxide Catalyst Supported on Microporous and Mesoporous HZSM-5 for Co-aromatization of Methane and Propane, and Production Method of BTX Using Said Catalyst

Info

Publication number: KR101862683B1
Application number: KR1020160171251A
Authority: KR
Inventors: 송인규; 김민영; 한승주; 송창열; 김도희; 이관영
Original assignee: 서울대학교산학협력단
Priority date: 2016-12-15
Filing date: 2016-12-15
Publication date: 2018-07-04

Abstract

The present invention relates to a metal oxide catalyst supported on microporous and mesoporous zeolite for a dehydrogenation aromatization reaction of mixed gas of methane and propane, and a method for manufacturing benzene, toluene, and xylene (BTX) using the same. More specifically, the present invention relates to a method for manufacturing a metal oxide catalyst supported on microporous and mesoporous HZSM-5, and a method for manufacturing BTX from a dehydrogenation aromatization reaction of methane and propane by using the catalyst.

Description

METHOD FOR MANUFACTURING METAL OXIDE CATALYST SUPPORTED ON HZSM-5 AND METHOD FOR MANUFACTURING BTX USING THE SAME, AND METHOD FOR MANUFACTURING METHOD FOR USING METHOD AND METHOD FOR HYDROXY- 5 for Co-aromatization of Methane and Propane, and Production Method of BTX Using Said Catalyst}

The present invention relates to a process for producing a catalyst capable of increasing the BTX feed rate in a dehydrogenating aromatization reaction of a methane-propane mixture gas and a process for producing BTX through a dehydrogenation reaction of a methane-propane mixture gas using the catalyst .

Methane and propane are basic alkanes composed of one and three carbons, one of the materials that are currently mostly used as energy sources due to their low reactivity despite their industrial value. However, as the supply of methane and propane is expected to increase due to the development of shale gas and the development of various natural gas sources in North America, attempts have been made to produce high value-added products using methane and propane as low- . Representative examples of the production include BTX (benzene, toluene and xylene).

BTX is used in the manufacture of synthetic resins, detergents and rubbers, and most of the existing commercial processes for making BTX are naphtha reforming-based processes. Until now, there have been very few successful commercialization of methane or propane using alkane as a direct raw material due to rapid catalyst deactivation.

However, the development of high value-added processes for hard paraffins such as methane and propane has shown great potential with the development of new approaches to manufacturing high value-added products using hard paraffin over the last 10 years.

In the United States, Chevron Research Company has conducted a study on a method for producing hydrocarbons from a methane mixture gas containing C2 to C4 hydrocarbons through a continuous catalytic process (Patent Document 1). In the National Chemical Laboratory of India, A study on a process for producing aromatic compounds or heavy hydrocarbons from a light alkene mixture was conducted using a pentasil zeolite bifunctional catalyst having strong active dehydrogenation reaction sites or strong acid sites (Patent Document 2).

Also, Saudi Basic Industries Corporation Inc. conducted a study on the aromatization of C1 to C4 alkanes using a Cycler process process under Pt / ZSM-5 (Patent Document 3).

Representative examples of commercial processes include the BP-UOP CYCLAR process for the production of aromatics from propane and butane as reactants. This commercial process uses a gallium-doped zeolite catalyst and includes a Continuous Catalyst Regeneration (CCR) process to remove coke and byproducts. However, since there is no commercially available process for producing aromatics using methane as the main reactant, the dehydrogenation technology of methane in which propane is introduced as a co-reactant is worth research and development.

Since the reaction for producing BTX from methane is a thermodynamically endothermic reaction and requires a high temperature reaction at 600 ° C or higher, there is a limit point that is difficult to commercialize due to a decrease in reaction efficiency due to a high reaction temperature and a rapid catalyst deactivation due to coke deposition Document 1).

In order to solve the above problems, many studies have been conducted recently. As a representative example, the dehydrogenation reaction of methane with a high carbon number of alkane and alkene introduced on an H-Galloaluminosilicate zeolite catalyst was carried out at a low temperature reaction at 400 to 600 ° C (Non-patent Document 2), and a Zn / HZSM-11 catalyst The dehydrogenation reaction of methane in which n-pentane was introduced as a co-reactant was carried out in a low-temperature reaction at 500 ° C (Non-Patent Document 3).

The introduction of propane as a co-reactant has the advantage of thermodynamically activating methane and propane at low temperatures, thereby solving the problem of the existing methane to high carbon number hydrocarbons (Non-Patent Document 4).

As a typical catalyst system, there is HZSM-5 containing gallium and zinc, and in the case of the dehydrogenation reaction of methane in which propane is introduced as a co-reactant, the dehydrogenation reaction of methane and propane is more preferable than the dehydrogenation reaction Exhibits excellent activity (Non-Patent Document 5).

In the dehydrogenation of methane and propane, methane and propane are activated by gallium and zinc oxides, and the oligomerization reaction proceeds by the acid sites of HZSM-5 to produce BTX.

In the case of the conventional commercial HZSM-5, it is composed of only a microcavity, which is disadvantage in that large molecular substances such as BTX can not easily escape from the catalyst layer in terms of mass transfer. However, when HZSM-5 is synthesized by using a carbon template, and then the carbon template is removed through the combustion process, the mesopores are formed. HZSM-5, in which the micropores and the mesopores are mixed, The advantages of HZSM-5, which is a mixture of micropores and mesopores, are not only high BTX selectivity due to the nature of shape selectivity due to micropores, but also advantageous in terms of mass transfer due to the formation of mesopores. The accessibility of reactants can be improved and the diffusibility of the product can be improved, so that the reaction activity can be improved as compared with the case of using conventional commercial HZSM-5 (Non-Patent Document 6). However, if the mesopore size is too large, the effect of the shape selectivity of the mesopore is reduced. If the mesopore size is too small, the mass transfer efficiency of the mesopore can not be improved.

Also, in the above non-patent document 6, as a result of the aromaticization reaction using only methane, it is considered that the proper volume of the mesopores is also different because methane and propane mixed gas are different from the methane-only mechanism of forming dehydrogenation aromatics .

In the formation of the mesopores and the volume control, the template material is preliminarily mixed at the time of preparing the catalyst such as zeolite to place the template material inside the zeolite, and subsequently the template material is removed by baking or the like, The volume of the mesopores can be controlled by the mixing amount of the template material.

The present inventors have found that when introducing mesopores into a catalyst using a conventional commercial HZSM-5 in the dehydrogenation reaction of methane in which propane is introduced as a co-reactant, BTX can be produced more efficiently by increasing the mass transfer rate And to optimize the volume ratio of the mesopores of the mesopores, by preparing a catalyst carrying metal oxide on HZSM-5 having mesopores introduced therein. However, unlike the expectation, it has been confirmed that the yield of BTX is influenced by the amount of the template material introduced for the production of the mesopores rather than the volume of the mesopores in the dehydrogenation reaction of the mixture gas of methane and propane to complete the present invention .

(Patent Document 1) U.S. Patent No. 04814534 (Daphne Lewis, Riason P. Al.) 1989.03.21. (Patent Document 2) U.S. Pat. No. 5,936,135 (Chowood Haribasan al., Kinaji Anil K., Chowdhary Torsar V.) 1999.08.10. (Patent Document 3) European Patent Registration No. 04815970.1 (Mitchell Scott F., Jutu Kofa Lakrishnan, Smith Robert Scott) 2006.09.13.

(Non-Patent Document 1) J.J. Spivey, G. Hutchings, Chem. Soc. Rev. 43, 792 (2014) (Non-Patent Document 2) V.R. Choudhary, A.K. Kinage, T.V. Choudhary, Science 275, 1286 (1997) (Non-Patent Document 3) O.A. Anunziata, G.A. Eimer, L.B. Pierella, Catal. Lett. 87, 167 (2003) (Non-Patent Document 4) J. Guo, H. Lou, X. Zheng, J. Nat. Gas Chem. 18, 260 (2009) (Non-Patent Document 5) H.T. Zheng, H. Lou, X.M. Zheng, Chin. J. Catal. 25, 255 (2004) (Non-Patent Document 6) H. Liu, S. Yang, J. Hu, F. Shang, Z. Li, C. Xu, J. Guan, Q. Kan, Fuel Process. Technol. 96, 195 (2012)

SUMMARY OF THE INVENTION The present invention provides a process for producing a catalyst capable of further increasing the yield of BTX in the production of BTX (benzene, toluene and xylene) by a dehydrogenation reaction of a mixed gas of methane and propane.

Another object of the present invention is to provide a method for efficiently producing BTX from a dehydrogenation reaction of a methane-propane mixed gas using a supported catalyst composed of a metal oxide supported on HZSM-5 in which the micropores and the mesopores are mixed .

According to an aspect of the present invention, there is provided a method for preparing a metal oxide catalyst supported on HZSM-5, wherein a micropores and mesopores for a dehydrogenation reaction catalyst of a mixed gas of methane and propane are mixed, comprising the steps of do.

In one embodiment of the present invention, the catalyst for the dehydrogenation reaction of a methane-propane mixed gas comprises (a) dissolving sodium hydroxide, a silicon precursor, an aluminum precursor, tetrapropylammonium bromide, and a carbon template material in a first solvent Preparing a mixed precursor solution; (b) hydrothermally synthesizing the mixed precursor solution prepared in step (a) in a hydrothermal synthesis reactor; (c) firing the solid material obtained in the step (b) in an air atmosphere to remove the carbon template material; (d) synthesizing HZSM-5 in which the solid material obtained in the step (c) is mixed with an aqueous ammonium salt solution and the micropores and the mesopores are mixed through an ion exchange and a sintering process; (e) dispersing the solid material obtained in step (d) in a second solvent in which gallium or zinc precursor is dissolved to carry gallium or zinc precursor; (f) removing the solvent after the step (e) and firing the obtained product to obtain a HZSM-5 catalyst carrying gallium oxide or zinc oxide; Wherein the content of the carbon-based template material in step (a) is 0.25 to 1% by weight based on the total weight of Si and Al.

In one preferred embodiment of the present invention, the silicon precursor used in the step (a) is at least one selected from the group consisting of colloidal silica, tetraethylorthosilicate, tetrapropyl orthosilicate and tetrabutyl orthosilicate, Is at least one selected from aluminum sulfate, aluminum nitrate, aluminum hydroxide, aluminum oxide, aluminum carbonate, aluminum acetate, aluminum chloride and sodium aluminate, and the carbon template material is BP-2000.

In one preferred embodiment of the present invention, the first solvent used in the step (a) is at least one selected from the group consisting of water, methanol, ethanol, 1-propanol, 2-propanol, butanol, 1-heptanol, , 4-methyl-1-heptanol, benzyl alcohol, 1,2-ethanediol, diethylene glycol and trimethylene glycol.

In a preferred embodiment of the present invention, the hydrothermal synthesis of the step (b) is performed at a temperature of 150 to 180 ° C and 3 to 5 bar for 60 to 80 hours.

In a preferred embodiment of the present invention, the calcination in step (c) is performed at 500 to 600 ° C for 8 to 12 hours.

In a preferred embodiment of the present invention, the ion exchange in step (d) is performed at 80 to 130 ° C for 3 to 6 hours, and the calcination is performed at 500 to 600 ° C for 3 to 6 hours.

In a preferred embodiment of the present invention, the BTX production method using a dehydrogenation reaction of a methane-propane mixture gas is carried out at a temperature of 450 to 600 ° C under a gas hourly space (GHSV) condition in the presence of the catalyst prepared by the above- Velocity) of 100 to 20000 ml / g-catalyst · h. 20 to 50 vol% of methane, 2 to 5 vol% of propane, and 45 to 78 vol% of nitrogen in the mixed gas.

According to the present invention, it is possible to produce BTX (benzene, toluene and xylene) from a mixed gas of methane and propane, whose demand and value are gradually increasing globally. In addition, it is possible to obtain economical benefits by directly producing BTX from methane and propane, which are competitive in price, by breaking away from dependence on crude oil as a process different from the conventional naphtha reforming process, and it is advantageous to actively cope with market changes in the future .

The catalyst developed by the present invention is a supported catalyst composed of gallium or zinc oxide supported on HZSM-5 in which micropores and mesopores are mixed, and supported on gallium or zinc oxide supported on commercial HZSM-5 having only micropores BTX can be obtained at a higher yield than the supported catalyst.

1 shows the nitrogen adsorption / desorption isotherms of X-HZSM-5 (X is the weight% of the carbon matrix material relative to the total weight of Si and Al) and micro-HZSM-5 according to the present invention.
FIG. 2 is a graph showing the X-ray diffraction analysis results of X-HZSM-5 (X is weight% of carbon matrix material relative to the total weight of Si and Al) and micro-HZSM-5 according to the present invention.
Figure 3 (a) is a graph showing the results of an X-HZSM-5 (X is weight percent of the carbon matrix material relative to the total weight of Si and Al) and a mixture of methane and propane on a gallium oxide catalyst supported on micro-HZSM- (B) is a graph comparing the results of the BTX selectivity and the yield.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In general, the nomenclature used herein is well known and commonly used in the art.

Throughout this specification, when an element is referred to as " including " an element, it is understood that the element may include other elements as well, without departing from the other elements unless specifically stated otherwise.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail to avoid obscuring the subject matter of the present invention.

In addition, since the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention, It is to be understood that equivalents and modifications are possible.

Hereinafter, a metal oxide catalyst supported on a zeolite containing micropores and mesopores for a dehydrogenation reaction of a mixed gas of methane and propane according to the present invention and a method for producing BTX using the same will be described in detail with reference to the accompanying drawings.

The catalyst for the dehydrogenation reaction of a methane-propane mixed gas of the present invention comprises: (a) dissolving sodium hydroxide, a silicon precursor, an aluminum precursor, tetrapropylammonium bromide, and a carbon template in a first solvent to prepare a mixed precursor solution ; (b) hydrothermally synthesizing the mixed precursor solution prepared in step (a) in a hydrothermal synthesis reactor; (c) firing the solid material obtained in the step (b) in an air atmosphere to remove the carbon template material; (d) synthesizing HZSM-5 in which the solid material obtained in the step (c) is mixed with an aqueous ammonium salt solution and the micropores and the mesopores are mixed through an ion exchange and a sintering process; (e) dispersing the solid material obtained in step (d) in a second solvent in which gallium or zinc precursor is dissolved to carry gallium or zinc precursor; (f) removing the solvent after the step (e) and firing the obtained product to obtain a HZSM-5 catalyst carrying gallium oxide or zinc oxide; .

The sodium hydroxide used in step (a) is used to form a basic condition, and tetrapropylammonium bromide is used as a template material to form micropores.

The silicon precursor used in step (a) may be any of the commonly used precursors. Generally, silicon precursors include colloidal silica, tetraethylorthosilicate, tetrapropyl orthosilicate, tetrabutyl orthosilicate, It is preferable to use at least one selected from the same compounds, and it is particularly preferable to use tetraethylorthosilicate.

The aluminum precursor used in step (a) may be any of the commonly used precursors. Generally, aluminum precursors include aluminum sulfate, aluminum nitrate, aluminum hydroxide, aluminum oxide, aluminum carbonate, aluminum acetate, It is preferable to use at least one selected from compounds such as aluminum chloride and sodium aluminate, and it is particularly preferable to use sodium aluminate.

The carbon matrix material used in the step (a) is BP-2000 sold by Cabot.

The first solvent used in step (a) may be water or an alcohol such as methanol, ethanol, 1-propanol, 2-propanol, butanol, 1-heptanol, -Heptanol, benzyl alcohol, 1,2-ethanediol, diethylene glycol and trimethylene glycol, and it is preferable to use at least one selected from the group consisting of water, and it is particularly preferable to use water.

In the hydrothermal synthesis using the batch reactor in the step (b), the temperature is 140 to 200 ° C., preferably 150 to 180 ° C., the hydrothermal synthesis time is 50 to 100 hours, preferably 60 to 80 hours, bar, preferably 3 to 5 bar.

The purpose of firing the solid material in the air atmosphere in the step (c) is to form the mesopores by burning the carbon mold material. The firing conditions for synthesizing the general HZSM-5 and the firing conditions for the carbon mold material, The firing temperature may be set to 450 to 650 ° C, preferably 500 to 600 ° C, and the firing process time may be set to 6 to 15 hours, preferably 8 to 12 hours.

In the step (d), a solid material is mixed with an aqueous ammonium salt solution to replace the sodium ion present in the solid material with ammonium ions through ion exchange, and the ammonium ion is replaced with a hydrogen ion form through a sintering process do. The ion exchange process is preferably carried out at a temperature of 70 to 150 ° C, preferably 80 to 130 ° C for 2 to 8 hours, preferably 3 to 6 hours.

In the step (d), in order to replace the substituted ammonium ion with the hydrogen ion, the calcination temperature is 450 to 650 ° C, preferably 500 to 600 ° C, and the calcination process time is 2 to 8 hours Can be set to 3 to 6 hours, and finally HZSM-5 is synthesized.

In the step (e), HZSM-5 is mixed with a gallium or zinc precursor, dispersed and dissolved in a second solvent, and wet impregnation is carried out for the purpose of obtaining a catalyst for dehydrogenating a dehydrogenation reaction gas mixture of methane and propane do.

In the step (e), the gallium or zinc precursor may be any of commonly used precursors. Generally, at least one selected from nitrate, chloride, carbonate, acetate, and ammonium salts is used And it is particularly preferable to use a nitrate or ammonium salt.

The second solvent used in the step (e) is the same as the first solvent, and is water or an alcohol such as methanol, ethanol, 1-propanol, 2-propanol, butanol, Hexanol, 4-methyl-1-heptanol, benzyl alcohol, 1,2-ethanediol, diethylene glycol and trimethylene glycol, and it is preferable to use at least one selected from them. Is particularly preferable.

The wet impregnation is carried out at a temperature of 70 to 110 ° C., preferably 80 to 100 ° C., and the stirring speed is 100 to 400 revolutions per minute, preferably 200 to 300 .

The present invention also relates to a process for the preparation of BTX (benzene, toluene and xylene) from a dehydrogenation reaction of methane and propane on a gallium oxide or zinc oxide catalyst supported on HZSM-5 mixed with micropores and mesopores, And a method for manufacturing the same.

The reaction temperature for promoting the dehydrogenation reaction of methane and propane is preferably 450 to 600 ° C, more preferably 500 to 600 ° C. When the reaction temperature is lower than 450 ° C, methane and propane are not activated, which is undesirable. When the reaction temperature is higher than 600 ° C, it is not preferable because of the decomposition reaction of propane and the production of light hydrocarbon.

The reactant composition ratio for promoting the dehydrogenation reaction of methane and propane is preferably 20 to 50 vol% of methane, 2 to 5 vol% of propane and 45 to 78 vol% of nitrogen, more preferably 30 to 40 vol% vol%, propane 3 to 4 vol%, and nitrogen 56 to 67 vol%.

When the reactants are supplied to the reactor in the dehydrogenation reaction of methane and propane, the amount of the reactant to be injected can be controlled by using a mass flow controller. The amount of the reactant to be injected is in the range of 100 to 20000 gass hourly space velocity (GHSV) / g-catalyst · h, more preferably 2000 to 8000 ml / g-catalyst · h. When the space velocity is less than 100 ml / g-catalyst · h, a large amount of coking may occur while the reaction of the catalyst occurs in a limited region, and the deactivation is accelerated by hot spots due to heat released during the reaction It is not desirable because it can happen. Also, a space velocity above 20,000 ml / g-catalyst · h is not desirable because the catalyst may not sufficiently catalyze while the reactants pass through the catalyst bed.

Hereinafter, the present invention will be described with reference to Production Examples, Examples and Comparative Examples.

Manufacturing example 1: X-ray diffraction (XRD) HZSM -5 ( X is Si And Al < RTI ID = 0.0 > Of the template material Weight%)

1.30 g of sodium hydroxide, 1.36 g of tetrapropylammonium bromide, 38.2 ml of tetraethylorthosilicate and 0.47 g of sodium aluminate were dissolved in 108 ml of distilled water to prepare a precursor solution, and the mixture was stirred at 40 ° C for 3 hours.

To the stirred solution was added BP-2000 as a carbon matrix material to the precursor solution to be 0.25, 0.5, 1, 3 and 5 wt%, respectively, relative to the total weight of Si and Al, and further stirred at 40 ° C for 3 hours Respectively.

Then, the mixture was injected into a batch reactor and crystallization was carried out at a temperature of 160 ° C for 72 hours. NaZSM-5 was prepared through the hydrothermal synthesis.

Thereafter, a washing process using 1000 ml of distilled water and a drying process at 110 ° C for 8 hours were performed.

The dried NaZSM-5 was heated to 5 ° C / min under an air atmosphere, and calcined at 550 ° C for 10 hours to burn the carbon mold material.

Then, 8.01 g of ammonium nitrate was dissolved in 100 ml of distilled water, and the mixture was ion-exchanged for 6 hours at a temperature of 85 ° C., washed with 1000 ml of distilled water, NH ₄ ZSM-5 was prepared by drying at 110 ° C for 8 hours.

The ion exchange process was performed twice in total.

The prepared NH ₄ ZSM-5 was put into a firing furnace under an air atmosphere, heated to 5 ° C./minute and maintained at 550 ° C. for 5 hours and finally fired to produce HZSM-5. The catalyst thus prepared was named X-HZSM-5, where X is the weight percent of the carbon matrix material relative to the total weight of Si and Al. For example, if the weight of the carbon-based mold material is 0.25 wt% of the total weight of Si and Al, it is designated as 0.25-HZSM-5. If the weight of the carbon mold material is 5 wt% Lt; / RTI >

compare Manufacturing example 1: only micropores exist HZSM Production of -5

The ion exchange process was performed twice in total.

The prepared NH ₄ ZSM-5 was put into a firing furnace under an air atmosphere, heated to 5 ° C./minute and maintained at 550 ° C. for 5 hours and finally fired to produce HZSM-5.

The catalyst thus prepared is different from Comparative Example 1 only in that a carbon template is not used. The catalyst was named micro-HZSM-5.

Manufacturing example 2: X-ray diffraction (X-ray diffraction) HZSM -5 ( X is Si And Al < RTI ID = 0.0 > Of the template material Weight%) and micro-pores only in micro- HZSM To -5 Supported gallium Oxide or Zinc Oxide Preparation of Catalyst

Preparation of a gallium oxide or zinc oxide catalyst, respectively supported on micro-HZSM-5 (where X is the weight percent of the carbon-based material relative to the total weight of Si and Al) and micro-HZSM-5 alone having micropores, .

0.09 g of the gallium nitrate precursor and 0.091 g of the zinc nitrate precursor were respectively added to 10 ml of distilled water to prepare a metal oxide precursor solution, and X-HZSM-5 (X is Si And micro-HZSM-5 were added to the prepared metal oxide precursor solution in an amount of 1 g each, until the water completely evaporated at a rate of 300 revolutions per minute at 85 캜. Lt; / RTI >

Thereafter, the resultant was dried at 100 ° C. for 8 hours, heated to 500 ° C. at a rate of 5 ° C. per minute, and maintained for 4 hours. It was named the prepared catalyst _{MO y / X-HZSM-5} (X is Si and Al wt% of the total, based on the weight of the carbon molding material) and _{MO y / micro-HZSM-5} . Where MO denotes a supported metal oxide such as gallium oxide or zinc oxide, and the subscript y denotes the number of oxygen bonded to the metal, which is a real number of 3 or less.

Analysis example 1: X-ray diffraction (XRD) HZSM -5 < / RTI > and micro- HZSM -5 Characteristic Analysis and Comparison

The X-HZSM-5 catalyst according to Production Example 1 of the present invention exhibits hysteresis in the nitrogen adsorption / desorption analysis, indicating that mesopores exist. On the other hand, the micro-HZSM-5 with only micropores showed a Langmuir-type adsorption / desorption isotherm, indicating that no mesopores existed.

Table 1 summarizes the results of nitrogen adsorption and desorption experiments of X-HZSM-5 and micro-HZSM-5 according to Production Example 1 and Comparative Production Example 1 above.

As can be seen from the results in Table 1, the specific surface area of the prepared catalyst is not greatly affected by the X value, that is, the weight percentage of the carbon matrix material relative to the total weight of Si and Al. However, when the carbon matrix material exists, The specific surface area tends to slightly increase as compared with micro-HZSM-5 having no pores.

FIG. 2 is a graph showing X-ray diffraction analysis results of X-HZSM-5 and micro-HZSM-5 according to Preparation Example 1 and Comparative Preparation Example 1 described above. All of the above catalysts showed characteristic peaks of HZSM-5 crystal phase, and it was confirmed that all of the catalysts formed thereby well formed HZSM-5 crystals.

Example 1: BTX production by dehydrogenation reaction of methane-propane mixture gas

BTX formation reaction by dehydrogenation reaction of methane and propane was carried out at 500 to 800 ° C using X-HZSM-5 catalyst supported on gallium oxide prepared in Preparation Example 2.

The ratio of the gas used in this embodiment was constituted by the volume ratio of methane: propane: nitrogen = 5: 7.5: 0.5. The injected amount of the reactant was 3900 ml / g-catalyst · h in terms of the gas hourly space velocity (GHSV) of methane, propane and nitrogen.

0.2 g of the X-HZSM-5 catalyst was filled in a quartz reactor prior to the dehydrogenation reaction of the mixed gas of methane and propane, and then the temperature was elevated at a rate of 5 ° C / min to the reaction temperature under a nitrogen atmosphere. Then, the dehydrogenation reaction of methane and propane was carried out by passing a mixed gas of methane and propane through the catalyst layer.

In this example, the conversion of reactants, the selectivity and the yield of BTX were calculated by the following equations (1), (2) and (3), respectively.

(1)

(2)

(3)

Table 2 shows the activity changes of the gallium oxide catalyst supported on GaO _y / 5-HZSM-5 prepared according to Production Example 2 of the present invention according to the reaction temperature after 1 hour reaction.

As the reaction temperature increased, the conversion of methane decreased to 650 ° C and then increased to 800 ° C. The conversion of propane tended to increase with increasing reaction temperature.

This is because the propane decomposition reaction occurs at a temperature after 600 ° C and the amount of light hydrocarbon which is a side reaction increases. The reaction amount of methane increases more than the amount of methane generated by the propane decomposition reaction at a temperature after 700 ° C, It shows a tendency to increase again.

That is, it can be concluded that a part of the propane conversion after 600 ° C is used for the propane cracking reaction.

BTX selectivity and yield increased up to 600 ℃ and decreased. This tendency is also related to propane decomposition reaction.

Example 2: a mixture of micropores and mesopores 5- HZSM To -5 Supported metal Oxide On the catalyst Dehydrogenation of Methane and Propane Depending on Metal Activation Point BTX production

The metal oxide catalyst supported on 5-HZSM-5 prepared in Preparation Example 2 was used to change the metal active sites and to conduct BTX production by dehydrogenation reaction of methane and propane.

The reaction temperature was set to 550 ℃ to search for metal active sites involved in the activation of methane and propane.

Table 3 shows the activity of the metal oxide catalyst supported on 5-HZSM-5 prepared according to Production Example 2 of the present invention according to the metal active site after 1 hour reaction. There was no significant difference in methane conversion between the five metal active species, but propane conversion was found to be high in gallium oxide and zinc oxide catalysts.

Catalysts with other metal active phases except gallium and zinc oxide showed higher than 20% propane conversion, but BTX selectivity was so low that the BTX yield was less than 2%.

Based on these results, it was concluded that gallium and zinc oxide were the metal species with excellent reaction activity in the dehydrogenation reaction of methane and propane mixed gas.

Example 3: X-ray diffraction (XRD) HZSM -5 ( X is Si And Al < RTI ID = 0.0 > Of the template material weight% ) And micro-pore-only micro- HZSM To -5 Supported gallium Oxide BTX production by methane and propane dehydrogenation over catalyst

Based on the results of Example 2, the type of metal supported on the HZSM-5 zeolite was changed to gallium, and in order to confirm the influence of the medium porosity, the X-HZSM- 5 was carried out on a gallium oxide catalyst supported on micro-HZSM-5, wherein X is the weight percentage of the carbon-based material relative to the total weight of Si and Al, and BTX was produced by methane and propane dehydrogenation.

The above-mentioned reaction temperature was set at 550 占 폚.

The ratio of the raw material gas was constituted by the volume ratio of methane: propane: nitrogen = 5: 7.5: 0.5. The injected amount of the reactant was 3900 ml / g-catalyst · h in terms of the gas hourly space velocity (GHSV) of methane, propane and nitrogen.

0.2 g of the catalyst X-HZSM-5 (X is the weight percentage of the carbon-based material relative to the total weight of Si and Al) catalyst was filled in the quartz reactor before the dehydrogenation reaction of the mixed gas of methane and propane, At a rate of 5 ° C / min. After reaching the reaction temperature, the dehydrogenation reaction of methane and propane was carried out by passing a mixed gas of methane and propane through the catalyst layer.

Fig. 3 is a graph showing the results of the X-HZSM-5 (X is the weight% of the carbon matrix material with respect to the total weight of Si and Al) and the micro-HZSM-5 prepared according to Comparative Production Examples 1 and 2 of the present invention And BTX selectivity and yield of methane and propane dehydrogenation aromatization over gallium oxide catalysts.

Table 4 shows conversion rates of methane and propane for each catalyst by initial, middle, and late stages. Table 5 shows the yield of BTX for each catalyst.

The methane conversion and the propane conversion of the gallium oxide supported on X-HZSM-5 prepared with the carbon matrix were higher than those of the gallium oxide supported on micro-HZSM-5 over the entire reaction time. The yields of the catalysts showed the same tendency.

The comparison of the gallium oxide catalysts supported on the X-HZSM-5 prepared with the carbon-based template material shows different degrees depending on the initial and late reaction times, and the weight percent of the carbon template material relative to the total weight of Si and Al As a result, it was confirmed that not only the catalytic activity but also the stability were affected.

For the initial methane conversion, the highest methane conversion was obtained on a 1 wt.% Catalyst based on the total weight of Si and Al and the highest methane conversion on a 0.5 wt.% Catalyst for the latter methane conversion. The conversion of methane to propane was consistent with that of methane conversion. This tendency was similar in BTX yield.

This is different from the case where the dehydrogenation aromatization reaction is carried out using only methane as the raw material gas. It has been reported that the presence of mesoporous material improves the accessibility of the reactants to the active sites in terms of mass transfer due to the presence of the mesoporous pores and allows rapid diffusion of the product, As well as the presence of the disease.

However, when a dehydrogenation reaction is carried out using a mixed gas of methane and propane as a raw material, it can not be explained that the BTX yield is simply changed by the presence of the medium pores.

As can be seen in Table 1, in the case of 5-HZSM-5 and 3-HZSM-5 containing 5 wt% or 3 wt% of the carbon matrix material relative to the total weight of Si and Al, The mass pore volume of 0.5-HZSM-5 and 0.25-HZSM-5 to which 0.5% by weight or 0.25% by weight of the carbon template material was added at 0.093 and 0.106, respectively, relative to the total weight of Si and Al was greater than 0.083 or 0.079 Able to know.

However, the yield of BTX through dehydrogenation reaction using a mixed gas of carbon and propane was lower than that of 0.5-HZSM-5, 0.25-HZSM-5, 3-HZSM-5 and 5-HZSM- It can be seen that it is bigger than 5.

The same tendency is observed in terms of the activity stability of the catalyst. That is, the yield of BTX in the latter half of the reaction was highest when the weight percentage of the carbon-based material was 0.5% by weight based on the total weight of Si and Al, followed by 0.25% by weight> 1% by weight> 3% by weight> 5% .

Generally, the activity of the catalyst is lowered toward the later stage of the reaction because the carbon is deposited on the active site as the reaction progresses, thereby blocking the active sites or preventing pores. Therefore, in terms of catalyst stability, many of the mesopores are expected to be advantageous. However, this was also the highest at 0.5 wt% of the carbon-based material compared to the total weight of Si and Al, the volume of the medium pores being relatively low.

Therefore, the precise cause is unknown, but the dehydrogenation reaction using methane-propane mixture gas as a raw material shows a specific tendency different from the dehydrogenation reaction using methane as a raw material. .

In the present invention, in the production of BTX by the dehydrogenation reaction using a mixed gas of methane and propane as raw materials, the production of the catalyst prepared so that the yield of BTX is remarkably high and the production of BTX using the same It is suggested that the method.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, I will understand. Accordingly, the technical scope of the present invention should be defined by the following claims.

Claims

A method for producing a catalyst for aromatic dehydrogenation reaction of methane-propane mixed gas,
(a) preparing a mixed precursor solution by dissolving sodium hydroxide, a silicon precursor, an aluminum precursor, tetrapropylammonium bromide, and a carbon template material in a first solvent;
(b) hydrothermally synthesizing the mixed precursor solution prepared in step (a) in a hydrothermal synthesis reactor;
(c) firing the solid material obtained in the step (b) in an air atmosphere to remove the carbon template material;
(d) synthesizing HZSM-5 in which the solid material obtained in the step (c) is mixed with an aqueous ammonium salt solution, and the micropores and the mesopores are mixed through ion exchange and sintering;
(e) dispersing the solid material obtained in step (d) in a second solvent in which gallium or zinc precursor is dissolved to carry gallium or zinc precursor;
(f) removing the solvent after the step (e) and firing the obtained product to obtain a HZSM-5 catalyst carrying gallium oxide or zinc oxide; , Wherein the content of the carbon-based mold material in step (a) is in a range of 0.25 to 1 wt% based on the total weight of Si and Al. The method for producing a catalyst for dehydro-

The method of claim 1, wherein the silicon precursor used in step (a) is at least one selected from the group consisting of colloidal silica, tetraethylorthosilicate, tetrapropyl orthosilicate, and tetrabutyl orthosilicate,
The aluminum precursor is at least one selected from aluminum sulfate, aluminum nitrate, aluminum hydroxide, aluminum oxide, aluminum carbonate, aluminum acetate, aluminum chloride and sodium aluminate,
And the carbon template material is BP-2000. The method for producing a catalyst for dehydrogenating aromatization reaction of a mixed gas of methane and propane.

The method according to claim 1,
The first solvent used in step (a) may be at least one selected from the group consisting of water, methanol, ethanol, 1-propanol, 2-propanol, butanol, 1-heptanol, Benzene alcohol, 1,2-ethanediol, diethylene glycol, and trimethylene glycol, in the presence of a catalyst.

The process according to claim 1, wherein the hydrothermal synthesis in step (b) is carried out at a temperature of 150 to 180 ° C and 3 to 5 bar for 60 to 80 hours. .

The method according to claim 1,
Wherein the calcination in step (c) is carried out at 500 to 600 ° C for 8 to 12 hours.

The method according to claim 1,
Wherein the ion exchange in step (d) is carried out at 80 to 130 ° C. for 3 to 6 hours, and the calcination is carried out at 500 to 600 ° C. for 3 to 6 hours. Gt;

A method for producing BTX through dehydrogenation reaction of methane-propane mixture gas,
A process for producing a catalyst having a gas hourly space velocity (GHSV) of 100 to 20000 ml / g at a temperature of 450 to 600 ° C in the presence of a catalyst prepared by the process of any one of claims 1 to 6, Wherein the reaction is carried out in the presence of a catalyst.

8. The method of claim 7,
The method for producing BTX by dehydrogenating a mixture gas of methane and propane in a dehydrogenation reaction is characterized in that the methane and propane mixed gas comprises 20 to 50 vol% of methane, 2 to 5 vol% of propane and 45 to 78 vol% of nitrogen. Process for the preparation of BTX by dehydrogenation.