KR20140068598A - Nano-sized crystal zeolite catalyst supported zinc and lanthanum, and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a zeolite catalyst which is a nano-sized crystal in which zinc and lanthanum are dipped and a method for producing same. More specifically, the zeolite catalyst includes a first particle having a size of 10 to 100 nm and a second particle having a size of 1 to 10 μm. Each of the second particles includes the first particles. The zeolite catalyst comprises: zeolite having a silica and alumina mole ratio (SiO2/Al2O3) of 50 to 80; and zinc and lanthanum that are dipped therein. The zeolite catalyst includes zinc and lantan that are co-precipitated therein as active ingredients of the catalyst in order to increase the selectivity of an aromatic compound, especially BTX. The selectivity of an aromatic compound and BTX can be remarkably increased when the aromatic compound is produced from ethanol using a fixed layer catalyst reactor by means of the co-precipitation and appropriate acid site of nano-sized crystal particles, zinc, and lanthanum.

Description

[0001] The present invention relates to a zeolite catalyst which is impregnated with zinc and lanthanum, and a method of producing the same. [0002] Nano-sized crystal zeolite catalysts supported by Zinc and Lanthanum,

The present invention relates to a zeolite catalyst, which is a nano-scale crystal impregnated with zinc and lanthanum, and a method for producing the same, and more particularly, to a zeolite catalyst composed of nano-sized crystals used as a catalyst material for producing an aromatic compound from ethanol, Impregnated zeolite catalysts and their preparation.

Benzene, toluene, and xylene, which are known as BTX, are the most widely used aromatic compounds for the production of various organic compounds and polymers. . Commercial processes for making such aromatics are known as petrochemical processes such as refolding and cracking of crude oil. However, globally, crude oil is expected to be depleted in decades if used at current consumption rates, based on previously discovered oilfields. In other words, the demand for petroleum has increased rapidly from 71.5 million barrels / day in 1996 to 86.4 million barrels / day in 2007, while crude oil discovery has been below the average of 10 Gbbl for the past three years, The number and average size of the finds are also significantly decreasing. In addition, due to the increase in demand for crude oil and the drop in discovery volume, international oil prices have been steadily rising to $ 60 (end 2006), $ 150 (July 20808), $ 79 (2009) and $ 110 (May 2011) Respectively.

On the other hand, as the price of crude oil increases, it is required to develop a new process for producing aromatics, especially BTX, which can replace the existing petrochemical process. In particular, bioethanol The aromatics manufacturing process used has the advantage of using ethanol, which is a raw material that can be easily obtained from alternative oil sources. Furthermore, bioethanol is the first commercialized product of bio-raw materials, and has already been used for transportation in Brazil and the like. In recent years, researches for producing bio-ethanol from natural gas, coal or non-edible biomass have been actively conducted worldwide, And a process for recycling the carbon dioxide generated in the manufacturing process is known, and a lot of research for producing a high-value compound using the process has been carried out.

BACKGROUND OF THE INVENTION [0002] Prior art for the production of aromatic compounds, which are currently known, is mainly directed to the production of aromatics using raw materials derived from petrochemical processes.

For example, prior patents such as US Patent 6423879B1, US Patent 20030004383A1, US7279608B2, USP 7323430B2, USPatent 7049260B2, and prior art publications (Journal of the Institute of Chemical Engineers 42 (2011) pp 860867 and Applied Catalysis A: General 316 (2007) pp. 3246) discloses a process for selectively producing para-xylene as a kind of aromatic compound by methylation using toluene and methanol as intermediates of petrochemicals as raw materials as reaction raw materials At this time, HZSM-5 is mainly used as a catalyst. In addition, a method has been employed in which a suitable acid point is added to the catalyst, or a surface treatment or the like is carried out using phosphoric acid, or a method in which palladium (Pd) is impregnated with a metal.

On the other hand, a method for producing aromatic compounds using ethanol as a raw material that can replace the petrochemical process has been mainly disclosed in the literature. Herein, in the preparation of an aromatic compound using ethanol as described above, a method of preparing a catalyst is described in Catalysis Letters Vol. 110, Nos. 12 (2006) pp. 85, a catalyst prepared by using ethanol as a raw material and impregnating Mo ₂ C with SiO ₂ or ZSM-5 (Si / Al = 40) as a catalyst was used. In this case, the selectivity of the aromatic compound was 24.8% Have been disclosed.

In addition, Chemical Engineering Journal 154 pp. 396400 discloses a catalyst in which Ga ₂ O ₃ or Fe ₂ O ₃ is impregnated with a catalyst, and in this case, the selectivity of the aromatic compound is about 20%.

Further, Catalysis in Industry, 2010, Vol. 2, No. 4, pp. 402420 discloses that the catalyst of 3% ZnO / 27% Al ₂ O ₃ / Fe-TaKE-50 (Si / Fe = 550) was used. In this case, the selectivity of the aromatic compound was about 20%

React. kinet. Catal. Lett. As a result of analyzing the selectivity of aromatic compounds using a catalyst impregnated with various metals into HZSM-5 (Si / Al ₂ = 29) (WHSV) of the reactant, ethanol, was about 0.0795, which is very low.

As described above, in the conventional method, a catalyst is prepared by impregnating a conventional zeolite with a metal to produce an aromatic compound from ethanol. However, since the zeolite has a single crystal form or an amorphous form, Are too large or small in size to limit the selectivity of the aromatic compound. Thus, the selectivity of the aromatic compound and BTX is as low as 50% or less.

On the other hand, in CN 101564696 A, zeolite having a molar ratio of SiO ₂ / Al ₂ O _{3 of} about 25 to 300 is used as a catalyst, and zeolite is impregnated with zinc, lanthanum, iron and zirconium alone to use as a catalyst. It has been disclosed that the zeolite can include a mixed sol of silica / alumina to increase the selectivity of aromatics from ethanol. However, in the method disclosed in the Chinese patent, the SiO ₂ / Al ₂ O ₃ molar ratio is applied so that the selectivity of the aromatic compound can not be imparted. When the silica / alumina sol is further included, the sol has pores in the zeolite There is a problem that there is a limit in giving the selectivity due to the reaction in the pores.

The present inventors have conducted studies on a specific type of zeolite catalyst differentiated from conventional zeolites capable of producing aromatic compounds with high selectivity from ethanol. The particles are composed of micro-sized particles, (Zn) and lanthanum (La) were used as the zeolite so that the respective crystals constituting the particles of the zeolite exhibited nano-size and the range of SiO ₂ / Al ₂ O ₃ ratio could exhibit better selectivity. ) At the same time to increase the selectivity of the aromatic compound, thereby completing the present invention.

An object of the present invention is to provide a zeolite catalyst, which is a nano-scale crystal impregnated with zinc and lanthanum, and a process for producing the same, and more particularly, to a process for producing a zeolite catalyst comprising nanoscale crystals used as a catalyst material for producing an aromatic compound from ethanol, Zeolite catalyst impregnated with zinc and lanthanum, and a process for producing the same.

In order to achieve the above object,

Wherein the secondary particles comprise a plurality of primary particles and have a silica to alumina mole ratio (SiO ₂ / Al (Al ₂ O _{3) 2} O ₃ ) of 50 to 80; And

And a zeolite catalyst containing zinc and lanthanum impregnated in the zeolite.

In addition,

Preparing a zeolite having a silica to alumina molar ratio (SiO ₂ / Al ₂ O ₃ ) of 50 to 80 (step 1); And

A step of impregnating the zinc precursor and the lanthanum precursor with the zeolite prepared in the step 1, followed by drying and calcining the zeolite (step 2).

The zeolite catalyst according to the present invention is a zeolite catalyst prepared by coprecipitating zinc and lanthanum as an active material of a catalyst to increase the selectivity of an aromatic compound, particularly BTX, It is possible to greatly increase the selectivity of an aromatic compound and BTX when an aromatic compound is prepared from ethanol.

1 is a flowchart sequentially showing an example of a process for producing a zeolite in a process for producing a zeolite catalyst according to the present invention;
2 is a photograph of the catalyst of Example 1 and Comparative Example 1 according to the present invention observed with a scanning electron microscope;
3 is a graph showing the X-ray diffraction analysis of the catalyst of Example 1 according to the present invention.

The present invention

Wherein the secondary particles comprise a plurality of primary particles and have a silica to alumina mole ratio (SiO ₂ / Al (Al ₂ O _{3) 2} O ₃ ) of 50 to 80; And

And a zeolite catalyst containing zinc and lanthanum impregnated in the zeolite.

Hereinafter, the zeolite catalyst according to the present invention will be described in detail.

The zeolite catalyst according to the present invention comprises zeolite consisting of primary particles having a size of 10 to 100 nm, that is, nano-sized primary particles and secondary particles having a size of 1 to 10 탆 composed of a plurality of the primary particles , And the molar ratio of silica to alumina (SiO ₂ / Al ₂ O ₃ ) of the zeolite is 50 to 80. Also, the zeolite catalyst according to the present invention comprises zinc and lanthanum impregnated in the zeolite.

The zeolite catalyst according to the present invention is a particularly preferable material to be used as a catalyst material for producing an aromatic compound from ethanol. The zeolite catalyst according to the present invention has a higher selectivity for aromatics than a catalyst used in the production of aromatic compounds from conventional ethanol Can be further improved.

Zeolite catalysts which have been used as catalytic materials in the production of aromatic compounds through conventional petrochemical processes such as zeolite catalysts, particularly refolding and cracking of crude oil, may be provided with appropriate acid sites or modified by surface treatment Has been used. In some cases, a zeolite catalyst impregnated with a metal such as palladium (Pd) has been used.

In addition, processes for producing aromatic compounds from ethanol for the reasons such as crude oil depletion and the like have been actively studied. Currently, catalysts used in the production of aromatic compounds from ethanol are produced by simply impregnating zeolite with metal to prepare catalysts. There is a problem that it is difficult to impart the selectivity of an aromatic compound because each crystal constituting the particle is too large or small in size and thus the selectivity of the aromatic compound and BTX is 50% or less There was a low problem.

Meanwhile, the zeolite catalyst according to the present invention includes zeolite composed of a plurality of primary particles having a size of 10 to 100 nm and secondary particles having a size of 1 to 10 μm. This is because the micro-sized particles show a nanocrystal structure composed of a plurality of nanosized particles, and the specific surface area of the zeolite increases due to the nanocrystal structure, and ultimately the zeolite Can be improved.

One of the characteristics of the zeolite that can act as a reaction in the particles is the distribution of acid sites. In the case of the zeolite composed of nanoparticles like the zeolite catalyst according to the present invention, since the particles are small and the external surface area is increased, But also on the outer surface. Accordingly, the zeolite particles of the present invention have a particle size of micro-size, and since the crystals constituting the micro-sized particles are nanoparticles, the reactivity of the surface of the catalyst is reduced, thereby being able to exhibit more favorable characteristics in terms of selectivity of the reaction.

At this time, the shape of the cross section of the primary particles constituting the zeolite is rectangular. This is because the shape of the primary particle section is a quadrangle, and the edges of each surface may contain a relatively large number of acid sites favorable to the reaction.

Meanwhile, the zeolite catalyst according to the present invention includes zinc and lanthanum impregnated with zeolite. The zinc and lanthanum are impregnated as an active material of zeolite, and when zinc and lanthanum are impregnated, the selectivity of an aromatic compound can be further improved when an aromatic compound is produced from ethanol of zeolite. At this time, the zinc and lanthanum are each impregnated at a ratio of 0.5 to 2.0 wt% with respect to the zeolite.

If the zinc and lanthanum are impregnated with the above-mentioned ratio, there is a problem that the selectivity of the aromatic compound is lowered when the aromatic compound is produced from ethanol.

Further, even when zinc or lanthanum is not impregnated at the same time and zinc or lanthanum is impregnated separately, there is a problem that the selectivity of an aromatic compound is lowered when an aromatic compound is produced from ethanol.

In the zeolite catalyst according to the present invention, the zeolite preferably has Si / Al of 25 to 40 and Si / Al ₂ of 50 to 80. This is related to the acid sites and acid strengths of zeolites. Generally, the zeolite has weak acidity and acid sites as the Si / Al ratio increases. However, when it is lower than the above range, There is a problem that the selectivity of the aromatic compound is lowered. When the concentration is higher than the above range, there is a problem that the conversion point from the ethanol to the aromatic compound is lowered because the acid point is hardly represented

The zeolite catalyst according to the present invention is a zeolite having a nanocrystal structure composed of a plurality of particles having micro-sized particles,

Zinc and lanthanum impregnated into the zeolite as an active material can improve the catalytic activity and improve the selectivity of aromatic compounds in the production of aromatic compounds from ethanol. Therefore, As the selectivity is improved, the yield of the aromatic compound production process can be improved.

In addition,

Preparing a zeolite having a silica to alumina molar ratio (SiO ₂ / Al ₂ O ₃ ) of 50 to 80 (step 1); And

A step of impregnating the zinc precursor and the lanthanum precursor with the zeolite prepared in the step 1, followed by drying and calcining the zeolite (step 2).

Hereinafter, the method for producing the zeolite catalyst according to the present invention will be described in detail for each step.

In the method for producing a zeolite catalyst according to the present invention, step 1 is a step of producing a zeolite having a silica to alumina molar ratio (SiO ₂ / Al ₂ O ₃ ) of 50 to 80.

Zeolite is composed of components of silica and alumina. The zeolite having a high Si / Al molar ratio and a high silica content is known as high silica zeolite. The zeolite has a low polarity point and is hydrophobic and has high hydrothermal stability. In this case, most zeolites have a Si / Al molar ratio of 5 or less. Therefore, when the Si / Al molar ratio is 5 or more, it is called high silica zeolite stable for hydrothermal treatment. At this time, in step 1, high silica silica zeolite having a high silica content is prepared, and zeolite suitable for increasing the selectivity of aromatic compounds from ethanol is prepared.

At this time, the zeolite produced through the step 1 exhibits a silica and alumina molar ratio (SiO ₂ / Al ₂ O ₃ ) of 50 to 80 in order to exhibit high aromatic selectivity when producing an aromatic compound from ethanol. This is related to the acid sites and acid strengths of zeolites. Generally, the zeolite has weak acidity and acid sites as the Si / Al ratio increases. However, when it is lower than the above range, There is a problem in that the selectivity of the aromatic compound is lowered. When the concentration is higher than the above range, there is a problem that the conversion point from the ethanol to the aromatic compound is lowered because the acid sites are hardly represented, 1, a zeolite having a silica to alumina molar ratio (SiO ₂ / Al ₂ O ₃ ) of 50 to 80 is prepared.

On the other hand, the zeolite of the step 1 can be produced by a process including the following steps in detail, as shown in the flowchart of FIG.

The zeolite of step 1

Mixing a template and distilled water, adding and mixing a silica precursor, an aluminum precursor, sodium hydroxide, and distilled water, followed by gelation (step a);

Crystallizing the gel of step a) to form a zeolite crystal (step b);

Washing the zeolite crystals formed in step b, followed by drying and calcining to prepare a zeolite (step c);

(Step d) of ion exchanging the zeolite prepared in step c).

In the step (a), a silica precursor, an aluminum precursor, sodium hydroxide and distilled water are added to a mixture of the preform and distilled water used as a mold in the production of zeolite, and then the mixture is mixed. Of a silica-aluminum mixed gel is formed.

At this time, tetramethylammonium bromide (TPABr), tetrapropylammonium hydroxide (TPAOH), hexamethyleneimine (HMI) and the like can be used as the template in the step a)

As the silica precursor, tetraethylorthosilicate (TEOS), silica sol, fumed silica, etc. may be used.

As the aluminum precursor, aluminum nitrate (Al (NO ₃ ) ₃ 9H ₂ O), aluminum alkoxide and the like can be used.

On the other hand, the distilled water used in step a is preferably contained in a molar ratio of 5 to 20 based on the silica precursor. When distilled water is used at a molar ratio outside the above range, there is a problem that the selectivity of the zeolite to be produced is lowered, and thus the selectivity of aromatic compounds can not be exhibited even when the zeolite catalyst is applied to the aromatic compound from ethanol.

Wherein step b) crystallizes the gel of step a) to form zeolite crystals, wherein the crystallization of step b) can be performed by heating the amorphous silica aluminum mixed gel prepared in step a) into a high-pressure reactor and heating, The crystallization may be performed at a temperature of 150 to 200 DEG C for 12 to 48 hours.

However, the crystallization is not limited thereto, and can be performed through an appropriate process capable of crystallizing the amorphous silica aluminum mixed gel.

The step c is a step of washing zeolite crystals formed in step b and drying and calcining the zeolite crystals to prepare zeolite crystals. The zeolite crystals formed in step b are repeatedly washed with distilled water several times until the pH is neutral , Followed by drying and calcining the zeolite.

At this time, it is preferable that the drying is performed at a temperature of 100 to 150 ° C. for 10 to 20 hours to completely remove residual moisture,

The calcination may be carried out in an air atmosphere at a temperature of 500 to 600 DEG C for 3 to 6 hours, but the drying and calcination are not limited to the above conditions.

The step (d) is a step of ion-exchanging the zeolite prepared in step (c), wherein a sodium group (Na) is attached to the end group of the zeolite prepared in step (c) The sodium group of the terminal group is replaced with hydrogen by ion exchange of a zeolite having a sodium group attached thereto.

At this time, the ion exchange can be carried out using 1N NH ₄ Cl at a temperature of 80 ° C for about 3 hours, but the ion exchange is not limited thereto, and an appropriate process for replacing the terminal group of zeolite with hydrogen Lt; / RTI >

After the ion exchange of step (d) is performed, the crystal is washed several times until the pH of the zeolite is neutral, and the drying and calcination steps are repeated to finally produce the crystalline zeolite.

Meanwhile, the zeolite of step 1 having a silica to alumina molar ratio (SiO ₂ / Al ₂ O ₃ ) of 50 to 80 may be prepared through the above-described processes, but the zeolite manufacturing process of step 1 is not limited thereto, A zeolite can be prepared by appropriately selecting a process capable of producing a zeolite having a silica to alumina molar ratio (SiO ₂ / Al ₂ O ₃ ) of 50 to 80.

In the method for preparing a zeolite catalyst according to the present invention, the step 2 is a step of impregnating the zinc precursor and the lanthanum precursor with the zeolite prepared in the step 1, followed by drying and calcining.

In step 2, the zinc precursor and the lanthanum precursor are impregnated with the zeolite prepared in step 1 to impregnate the zeolite produced in step 1 with zinc and lanthanum, which are active materials, and the zeolite impregnated with zinc and lanthanum is dried and calcined, Can be manufactured.

At this time, Zn (NO ₃ ) ₂ .6H ₂ O, ZnCl ₂ and the like can be used as the zinc precursor in the step 2,

As the lanthanum precursor, La (NO ₃ ) ₃ .6H ₂ O, LaCl ₃ .7H ₂ O and the like may be used, but the precursor materials are not limited thereto.

It is preferable that the zinc precursor and the lanthanum precursor are impregnated with zeolite so that the impregnation amounts of zinc and lanthanum are respectively 0.5 to 2.0 wt%. This is because the characteristics of the zeolite catalyst prepared according to the impregnation amount of the zinc and lanthanum impregnated into the zeolite may be deteriorated.

That is, when the aromatic compound is produced from ethanol, when the amount of the impregnated zeolite impregnated with zeolite is in the range of 0.5 to 2.0 wt% based on the zeolite, high selectivity may be exhibited. However, The zinc precursor and the lanthanum precursor are preferably impregnated with zeolite so that the impregnation amounts of zinc and lanthanum in the zeolite are respectively 0.5 to 2.0 wt%.

In addition, the zinc precursor and the lanthanum precursor may be impregnated at the same time, or the zinc precursor and the lanthanum precursor may be sequentially impregnated, but it is more preferable that the zinc precursor and the lanthanum precursor are simultaneously impregnated. This is because when the zinc precursor and the lanthanum precursor are simultaneously impregnated, the aromatic compound selectivity can be further improved.

The drying of step 2 is preferably carried out at a temperature of 100 to 150 ° C. for 10 to 20 hours to completely remove residual moisture,

The calcination may be carried out in an air atmosphere at a temperature of 500 to 600 DEG C for 3 to 6 hours, but the drying and calcination are not limited to the above conditions.

The zeolite catalyst prepared through the above-described method comprises a zeolite having zeolite particles having micro-sized particles, the zeolite having a nanocrystal structure composed of a plurality of particles having nanosized particles as micro-sized particles, Zinc and lanthanum, and the molar ratio of silica to alumina (SiO ₂ / Al ₂ O ₃ ) is 50 to 80.

Since the zeolite produced by the production process according to the present invention exhibits the above-described characteristics, it is possible to improve the selectivity of aromatic compounds by applying it in the production of aromatic compounds from ethanol, As the selectivity is improved, the yield of the aromatic compound production process can be improved.

Further, the present invention provides a method for producing an aromatic compound from ethanol using the zeolite catalyst as a catalyst material,

According to the above production method, an aromatic compound prepared from ethanol is provided using a zeolite catalyst as a catalyst material.

As described above, the zeolite catalyst according to the present invention is characterized in that it comprises a zeolite consisting of micro-sized particles, the zeolite exhibiting a nanocrystal structure composed of a plurality of particles having micro-sized particles of nano- Zinc and lanthanum are impregnated with the material, and the molar ratio of silica and alumina (SiO ₂ / Al ₂ O ₃ ) is 50 to 80.

Accordingly, the present invention provides a process for producing an aromatic compound from ethanol using the zeolite catalyst as a catalytic material, and by applying the zeolite exhibiting the above characteristics to a process for producing an aromatic compound from ethanol, There is an effect that the degree of freedom can be improved.

At this time, the above production method of producing an aromatic compound from ethanol can be carried out using a fixed bed catalytic reaction system,

For example, a zeolite catalyst is filled in a tubular reactor, and hydrogen gas is flowed at a constant flow rate to reduce the catalyst. The temperature of the reactor is kept constant at the reaction temperature, and the raw material ethanol is continuously supplied . At this time, the fixed bed catalytic reaction system may be performed using a known catalytic reaction system, and the method for producing an aromatic compound from ethanol according to the present invention is not limited thereto.

In addition, the present invention provides an aromatic compound produced by the above process.

Since the aromatic compound is preferably selected from benzene, toluene, and xylene, and can be prepared at a high selectivity from the ethanol produced using the zeolite catalyst, the aromatic compound according to the present invention can be produced with high yield and high purity. have.

Hereinafter, the present invention will be described more specifically by way of examples. However, the following examples are intended to illustrate the present invention, but the scope of the present invention is not limited by the following examples.

≪ Preparation Example 1 &

Tetrapropylammonium bromide (TPABr) was used as a template, and the template and distilled water were placed in a teflon container and stirred at room temperature for 2 hours.

Then, tetraethyl orthosilicate (TEOS) was added thereto, and the mixture was further stirred for 2 hours. After adding aluminum nitrate (Al (NO ₃ ) ₃ .9H ₂ O), sodium hydroxide (NaOH) and distilled water , And the mixture was stirred at a temperature of 55 DEG C for 24 hours. After the stirring was completed, the mixed solution was gelated with an amorphous silica aluminum mixed gel having a lucid color.

The composition of the mixed solution was 0.5 TPABr: 1.25 SiO ₂ : 0.05 Al (NO ₃ ) ₃ .9H ₂ O: 0.5 NaOH: 3 H ₂ O (molar ratio).

Further, in order to crystallize the amorphous silica-aluminum mixed gel, the gel was injected into a high-pressure reactor and heated at 180 ° C. for 24 hours to form zeolite crystals. The prepared zeolite crystals were cooled to room temperature and then centrifuged to separate into an aqueous solution layer and a solid matter layer. The separated zeolite crystals were washed with distilled water until the pH of the separated zeolite crystals became neutral.

The washed zeolite was then placed in a dryer and dried at a temperature of 120 ° C for 12 hours, and the dried zeolite was calcined in an air atmosphere at a temperature of 550 ° C for 5 hours.

The calcined zeolite is in the form of Na-ZSM-5 with sodium (Na) attached at the terminal end and the zeolite is ion exchanged with 1N NH ₄ Cl to produce zeolite in the form of H-ZSM-5. The ion exchange was carried out by immersing the zeolite with 1N NH ₄ Cl at a temperature of 80 ° C and stirring for 3 hours. The zeolite subjected to the ion exchange was thoroughly washed until the pH became neutral, At room temperature for 12 hours, and calcined in an air atmosphere at 550 DEG C for 5 hours to prepare a zeolite.

≪ Production Examples 2 to 11 &

Zeolite was prepared in the same manner as in Preparation Example 1, except that the molar ratio of alumina contained in the mixed solution and the molar ratio of distilled water were changed as shown in Table 1 below.

Table 1 also shows the average particle sizes (secondary particles) and crystal sizes (primary particles) of the zeolite prepared in Production Examples 1 to 11.

division Type of mold Alumina mole ratio Si / Al
Mole ratio Distilled water mole ratio
Average particle size
(μm) Crystal size
(nm) Production Example 1 TPABr 0.05 25 3 5 400 Production Example 2 TPABr 0.05 25 9 5 20 Production Example 3 TPABr 0.05 25 18 5 20 Production Example 4 TPABr 0.05 25 120 5 250 Production Example 5 TPABr 0.016 80 9 5 20 Production Example 6 TPABr 0.00446 280 9 25 150 Production Example 7 TPABr 0.0025 500 9 25 250 Production Example 8 TPABr 0.01 25 32 5 20 Production Example 9 TPABr 0.01 25 80 5 15 Production Example 10 TPAOH 0.05 25 120 0.9 200 Production Example 11 TPAOH 0.05 25 240 0.5 200

As shown in Table 1, it can be seen that the crystal size varies depending on the molar ratio of the distilled water in the preparation examples. Particularly, when the molar ratios of distilled water in Preparation Examples 1 and 4 were 3 and 120, the crystal sizes were 400 and 250 nm .

In addition, when TPAOH was used as a template in Production Examples 10 and 11, the average particle size was small and the crystal size was increased to 200 nm when the molar ratio of distilled water was large.

Furthermore, it can be seen that as the molar ratio of Si / Al increases, the average particle size and crystal size increase,

It can be seen from the characteristic results in Table 1 that the zeolite having nano-sized crystals can be prepared by controlling the molar ratio of Si / Al and the molar ratio of distilled water in the production method according to the present invention.

Example 1 Preparation of zeolite catalyst impregnated with zinc and lanthanum 1

Zn (NO ₃ ) ₂ .6H ₂ O and lanthanum precursor La (NO ₃ ) ₃ .6H ₂ O were impregnated with the zeolite prepared in Preparation Example 2 as a zinc precursor together and dried at 100 ° C. for 12 hours And calcined in an air atmosphere at a temperature of 550 ° C for 5 hours to prepare a zeolite catalyst impregnated with zinc and lanthanum.

At this time, the amount of the zinc precursor was controlled so that 0.8 weight% of zinc was impregnated into the prepared zeolite catalyst,

At this time, the amount of the lanthanum precursor was adjusted so that 0.6 wt% of lanthanum was impregnated into the prepared zeolite catalyst.

Examples 2 to 5 Preparation of zeolite catalyst impregnated with zinc and lanthanum 2 to 5

Zeolite catalyst impregnated with zinc and lanthanum was prepared in the same manner as in Example 1 except that zeolite prepared in Production Examples 3, 5, 8, and 9 was impregnated with zinc and lanthanum in Example 1, respectively. Respectively.

Example 6: Preparation of zeolite catalyst impregnated with zinc and lanthanum 6

The zeolite catalyst impregnated with zinc and lanthanum was prepared in the same manner as in Example 1 except that the zinc precursor and the lanthanum precursor were sequentially impregnated with the zeolite in Example 1.

Example 7: Preparation of zeolite catalyst impregnated with zinc and lanthanum 7

A zeolite catalyst impregnated with zinc and lanthanum was prepared in the same manner as in Example 1 except that the lanthanum precursor and the zinc precursor were sequentially impregnated with zeolite in Example 1.

Example 8: Preparation of zeolite catalyst impregnated with zinc and lanthanum 8

In Example 1, the zinc precursor was adjusted so that 1.2 wt% of zinc could be impregnated into the prepared zeolite catalyst,

The zeolite catalyst impregnated with zinc and lanthanum was prepared in the same manner as in Example 1, except that the amount of lanthanum precursor used was adjusted so that 0.6 wt% of lanthanum could be impregnated into the prepared zeolite catalyst.

Example 9 Preparation of zeolite catalyst impregnated with zinc and lanthanum 9

The amount of zinc precursor used in Example 1 was adjusted so that 2.0 wt% of zinc could be impregnated into the prepared zeolite catalyst,

The zeolite catalyst impregnated with zinc and lanthanum was prepared in the same manner as in Example 1, except that the amount of lanthanum precursor used was adjusted so that 0.6 wt% of lanthanum could be impregnated into the prepared zeolite catalyst.

Example 10 Preparation of zeolite catalyst impregnated with zinc and lanthanum 10

The amount of zinc precursor used in Example 1 was adjusted so that 0.8 wt% of zinc could be impregnated into the prepared zeolite catalyst,

The zeolite catalyst impregnated with zinc and lanthanum was prepared in the same manner as in Example 1 except that the amount of lanthanum precursor used was adjusted so that 1.0 wt% of lanthanum could be impregnated into the prepared zeolite catalyst.

≪ Comparative Examples 1 to 6 >

Zeolite impregnated with zinc and lanthanum was prepared in the same manner as in Example 1 except that zeolite prepared in Production Examples 1, 4, 6, 7, 10 and 11 was impregnated with zinc and lanthanum in Example 1, Catalyst.

≪ Comparative Example 7 &

Zeolite catalyst impregnated with zinc was prepared in the same manner as in Example 1, except that the zeolite catalyst prepared in Example 1 was impregnated with zeolite catalyst so that 0.8 wt% of zinc could be impregnated into the zeolite catalyst. .

≪ Comparative Example 8 >

The lanthanum-impregnated zeolite catalyst was prepared in the same manner as in Example 1 except that the lanthanum precursor alone was impregnated with 0.6 wt% .

≪ Comparative Example 9 &

In Example 1, the amount of zinc precursor was adjusted so that 0.4 wt% of zinc could be impregnated into the prepared zeolite catalyst,

The zeolite catalyst impregnated with zinc and lanthanum was prepared in the same manner as in Example 1, except that the amount of lanthanum precursor used was adjusted so that 0.6 wt% of lanthanum could be impregnated into the prepared zeolite catalyst.

≪ Comparative Example 10 &

The amount of gallium used as the gallium precursor in Example 1 was adjusted so that 0.8 wt% of gallium could be impregnated into the zeolite catalyst prepared using Ga (NO ₃ ) ₂ .xH ₂ O,

The lanthanum precursor was prepared in the same manner as in Example 1 except that the amount of the lanthanum precursor used was adjusted so that 0.6 wt% of lanthanum could be impregnated into the prepared zeolite catalyst to prepare gallium and lanthanum-impregnated zeolite catalysts.

≪ Comparative Example 11 &

The use amount of the zeolite catalyst prepared by using Cu (NO ₃ ) ₂ .2.5H ₂ O as a copper precursor in Example 1 was adjusted so that 0.8 wt% of copper could be impregnated,

The zeolite catalyst impregnated with copper and lanthanum was prepared in the same manner as in Example 1 except that the amount of lanthanum precursor used was adjusted so that 0.6 wt% of lanthanum could be impregnated into the prepared zeolite catalyst.

≪ Comparative Example 12 >

The amount of zinc precursor used in Example 1 was adjusted so that 7 wt% of zinc could be impregnated into the prepared zeolite catalyst,

The zeolite catalyst impregnated with zinc and lanthanum was prepared in the same manner as in Example 1, except that the amount of lanthanum precursor used was adjusted so that 0.6 wt% of lanthanum could be impregnated into the prepared zeolite catalyst.

≪ Comparative Example 13 &

The amount of the copper precursor was adjusted so that 8 wt% of copper could be impregnated into the zeolite catalyst prepared in Example 1,

The zeolite catalyst impregnated with copper and lanthanum was prepared in the same manner as in Example 1 except that the amount of lanthanum precursor used was adjusted so that 0.6 wt% of lanthanum could be impregnated into the prepared zeolite catalyst.

Experimental Example 1 Analysis of Catalytic Reaction in Preparation of Aromatic Compound from Ethanol

The catalytic reactions in the case where the zeolite catalyst prepared in Examples 1 to 10 and the zeolite catalysts prepared in Comparative Examples 1 to 13 according to the present invention were used as catalyst materials in the production of aromatic compounds from ethanol were analyzed.

At this time, the analysis was carried out using a fixed bed catalytic reaction system. That is, 0.65 g of the zeolite catalyst was filled in the tubular reactor, hydrogen gas was supplied at a constant rate of 10 cc / min, and the temperature was maintained at 550 ° C. for 3 hours to reduce the catalyst. Then, the temperature of the reactor was kept constant at a catalytic reaction temperature of 437 ° C. (710 K), and the reaction pressure was adjusted to normal pressure. Then, the raw material ethanol was continuously supplied to the reactor at a flow rate of 0.011 cc / min using a HPLC pump, and the weight hour space velocity (WHSV) was 0.8 cc / gcat · min Respectively. The product passed through the reactor was analyzed by gas chromatography (GC) in the condition that the temperature of the lower part of the reactor was maintained at 150 ° C. At this time, nitrogen gas not participating in the reaction was used as an internal standard, min, and the components of the product were quantitatively analyzed by GC based on the nitrogen component. The conversion of ethanol to aromatics and the selectivity of each product were calculated.

On the other hand, the column used for the gas chromatography analysis was Porapak-Q (2 m) as a GC column on the TCD side and DB-5 (30 m) and HP-Innowax (60 m) The analysis was carried out while raising the initial temperature from 40 占 폚 to 250 占 폚.

(1) Analysis of catalytic reactions according to applied zeolite

The catalytic reaction analysis was carried out using the zeolite catalysts prepared in Examples 1 to 5 and the zeolite catalysts of Comparative Examples 1 to 6, and the results are shown in Table 2 below.

division Of the catalyst used
Kinds Ethanol conversion rate
(%) Aromatic compound selectivity
(%) BTX
Selectivity
(%) 0 hr 30 hr 0 hr 30 hr 0 hr 30 hr Example 1 0.8% Zn + 0.6% La / Production example 2 100 100 62.8 56.7 54.8 47.2 Example 2 0.8% Zn + 0.6% La / Production Example 3 100 100 65.3 59.4 60.1 52.1 Example 3 0.8% Zn + 0.6% La / Production Example 5 100 99 61.6 56.7 54.8 47.2 Example 4 0.8% Zn + 0.6% La / Production Example 8 100 99.3 69.4 58.7 58.8 46.2 Example 5 0.8% Zn + 0.6% La / Production Example 9 100 100 62.1 56.1 55.2 47.7 Comparative Example 1 0.8% Zn + 0.6% La / Production Example 1 100 98.2 28.3 13.5 18.7 6.7 Comparative Example 2 0.8% Zn + 0.6% La / Production example 4 100 99.1 32.4 25.4 19.4 7.4 Comparative Example 3 0.8% Zn + 0.6% La / Production Example 6 100 99.4 27.7 31.3 21.4 20.2 Comparative Example 4 0.8% Zn + 0.6% La / Production Example 7 100 98.7 13.2 14.9 7.9 5.6 Comparative Example 5 0.8% Zn + 0.6% La / Production Example 10 99.8 98.5 18.3 4.7 13.5 1.4 Comparative Example 6 0.8% Zn + 0.6% La / Production example 11 99.5 97.7 18.6 5.6 12.5 2.3

As shown in Table 2, even if the same amounts of zinc and lanthanum are impregnated, it is understood that the selectivity of the aromatic compound and the selectivity of the BTX differ depending on the zeolite used. That is, when zeolite having nanocrystals such as zeolite of Production Examples 2, 3, 5, 8 and 9 is used, it is found that the selectivity of aromatic compound and the selectivity of BTX are also excellent. On the other hand, it can be seen that the selectivity is low when the zeolite having crystals of a size large enough not to be a nanocrystal is used in Production Examples 1, 4, 6, 7, 10, and 11.

From the above results, it was confirmed that the zeolite catalyst according to the present invention is composed of secondary particles having a nanocrystal structure, and thus it is possible to exhibit high selectivity when an aromatic compound is produced from ethanol.

(2) Analysis of catalytic reaction according to impregnation amount of zinc and lanthanum

The catalytic reaction analysis was performed using the zeolite catalysts prepared in Examples 6 to 10 and the zeolite catalysts in Comparative Examples 7 to 13, and the results are shown in Table 3 below.

division Of the catalyst used
Kinds Ethanol conversion rate
(%) Aromatic compound selectivity
(%) BTX
Selectivity
(%) 0 hr 30 hr 0 hr 30 hr 0 hr 30 hr Example 6 0.8% Zn / 0.6% La / Production Example 2 100 100 65.3 54.1 53.1 46.3 Example 7 0.6% La / 0.8% Zn / Production example 2 100 100 66.2 58.2 62.1 50.1 Example 8 1.2% Zn + 0.6% La / Production Example 2 100 100 62.6 57.5 56.2 46.2 Example 9 2.0% Zn + 0.6% La / Production Example 2 100 99.7 66.4 58.2 58.1 45.2 Example 10 0.8% Zn + 1.0% La / Production Example 2 100 100 60.1 55.1 53.7 48.2 Comparative Example 7 0.8% Zn / Production Example 2 100 98.2 28.3 13.5 18.7 6.7 Comparative Example 8 0.6% La / Production Example 2 100 99.1 32.4 25.4 19.4 7.4 Comparative Example 9 0.4% Zn + 0.6% La / Production Example 2 99.6 99.1 29.1 22.3 16.5 11.1 Comparative Example 10 0.8% Ga + 0.6% La / Production Example 2 100 99.4 27.7 31.3 21.4 20.2 Comparative Example 11 0.8% Cu + 0.6% La / Production example 2 100 98.7 13.2 14.9 7.9 5.6 Comparative Example 12 7% Zn + 0.6% La / Production Example 2 99.8 98.5 18.3 4.7 13.5 1.4 Comparative Example 13 8% Cu + 0.6% La / Production example 2 99.5 97.7 18.6 5.6 12.5 2.3

As shown in Table 3, the selectivity of the aromatic compound and the selectivity of the BTX are different depending on the impregnation amount of zinc and lanthanum. That is, even if the same zeolite is used, it can be seen that the zeolite catalysts of Examples 6 to 10 impregnated with 0.5 to 2.0 wt% of zinc and lanthanum exhibit high selectivity.

On the other hand, it can be seen that the selectivity of Comparative Examples 7 and 8 impregnated with zeolite alone or with lanthanum alone is lowered, and the selectivity of Comparative Example 9 containing less than 0.5% by weight of zinc is also lowered .

Further, it can be seen that the selectivity is lowered also in Comparative Examples 10 and 11 in which gallium or copper other than zinc is impregnated with lanthanum,

It can be seen that Comparative Examples 12 and 13 in which excess zinc or copper is impregnated exhibit much lower selectivity than the examples according to the present invention.

As a result of the above analysis, it was confirmed that the zeolite catalyst according to the present invention exhibits a very high selectivity when an aromatic compound is produced from ethanol according to the impregnation of an appropriate amount of zinc and lanthanum.

<Experimental Example 2> Scanning electron microscopic observation

The zeolite catalysts of Example 1 and Comparative Example 1 were observed through a scanning electron microscope and the results are shown in FIG.

As shown in Fig. 2, the zeolite catalyst of Example 1 was observed to be composed of a plurality of nanocrystals (secondary particles) having a square cross section. On the other hand, in the zeolite catalyst of Comparative Example 1, only particles having a polygonal structure were observed, and no nanocrystals were observed. As a result, it was confirmed that the zeolite catalyst according to the present invention formed particles composed of nanocrystals having a square cross section.

Experimental Example 3 X-ray diffraction analysis

The zeolite catalyst of Example 1 was analyzed by X-ray diffraction and the results are shown in FIG.

As shown in FIG. 3, the zeolite catalyst of Example 1 has a crystal structure of typical ZSM-5 having peaks at 2? = 5 - 10 and 2? = 20 - 30, Was found to have a typical ZSM-5 crystal structure.

Claims (10)

Wherein the secondary particles comprise a plurality of primary particles and have a silica to alumina mole ratio (SiO ₂ / Al (Al ₂ O _{3) 2} O ₃ ) of 50 to 80; And
Zeolite catalyst comprising zinc and lanthanum impregnated in said zeolite.
The zeolite catalyst according to claim 1, wherein the cross-section of the primary particles is rectangular.
The zeolite catalyst according to claim 1, wherein the zinc and lanthanum are each impregnated in a ratio of 0.5 to 2.0 wt% based on the zeolite.
The zeolite catalyst according to claim 1, wherein the zeolite catalyst is used as a catalyst for producing an aromatic compound from ethanol.
Preparing a zeolite having a silica to alumina molar ratio (SiO ₂ / Al ₂ O ₃ ) of 50 to 80 (step 1); And
A process for preparing a zeolite catalyst according to claim 1, comprising the step of impregnating the zinc precursor and the lanthanum precursor with the zeolite prepared in step 1, followed by drying and calcining (step 2).
The method of claim 5, wherein the zeolite of step 1
Mixing a template and distilled water, adding and mixing a silica precursor, an aluminum precursor, sodium hydroxide, and distilled water, followed by gelation (step a);
Crystallizing the gel of step a) to form a zeolite crystal (step b);
Washing the zeolite crystals formed in step b, followed by drying and calcining to prepare a zeolite (step c);
(Step d) of ion exchanging the zeolite prepared in step c). &Lt; RTI ID = 0.0 &gt; 11. &lt; / RTI &gt;
7. The method of claim 6, wherein the distilled water used in step (a) is contained in a molar ratio of 5 to 20 based on the silica precursor.
6. The zeolite catalyst according to claim 5, wherein the zinc precursor and the lanthanum precursor of step 2 are simultaneously impregnated so that the impregnation amounts of zinc and lanthanum in the zeolite of step 1 are respectively 0.5 to 2.0 wt% Way.
A process for producing an aromatic compound from ethanol using the zeolite catalyst of claim 1 as a catalytic material.
An aromatic compound prepared from ethanol by using the zeolite catalyst of claim 1 as a catalytic material according to the production method of claim 9.

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