KR100293530B1 - Trimetallosilicate Catalysts Containing Pt Inside Grids Useful for Aromatic Reactions of Hydrocarbons - Google Patents

Abstract

The present invention relates to a trimetallosilicate catalyst useful for the aromatization reaction of a hydrocarbon containing a metal component including Pt in a lattice and a method for producing an aromatic hydrocarbon using the same. The trimetallosilicate catalyst of the present invention is prepared by simultaneously dropping three metals, including Pt, into the appropriate precursor forms in the silica precursor during the preparation of the zeolite catalyst, so that all metal components including Pt are supported inside the zeolite lattice. In the trimetallosilicate catalyst of the present invention, since Pt is supported inside the zeolite lattice, Pt has a good dispersion of the Pt, excellent stability of catalytic activity, and in addition to Pt, two other metals capable of promoting aromatization of hydrocarbons. At the same time, it shows high catalytic activity. Therefore, when the trimetallosilicate catalyst of the present invention is used for the aromatization of aliphatic hydrocarbons, aromatic hydrocarbons can be produced in high yield.

Description

Trimetallosilicate catalysts containing P t in the lattice useful for aromatization of hydrocarbons

The present invention relates to trimetallosilicate catalysts useful for the aromatization of hydrocarbons. More specifically, the present invention relates to a trimetallosilicate catalyst useful for the aromatization reaction of a hydrocarbon containing a metal component including Pt in a lattice and a method for producing an aromatic hydrocarbon using the same.

Zeolite generally means crystalline aluminosilicate. Among these zeolites, HZSM-5, a kind of zeolite having an MFI structure, is disclosed in US Pat. No. 3,702,886. Also, there have been reported methods for preparing a catalyst useful for aromatization of hydrocarbons by modifying the electric HZSM-5. have. That is, U.S. Patent Nos. 5,456,822, 5,073,672, 4,705,907, and 4,704,494 disclose aromatics by substituting Al components of HZSM-5 with other metals such as Ga or Zn by impregnation, ion exchange or lattice substitution. It is disclosed that the catalytic activity for the oxidation reaction can be increased.

However, since the catalysts thus prepared are known to have faster deactivation than unmodified HZSM-5, there have been attempts to further suppress the deactivation of the electrocatalysts by further supporting Pt of the conventional zeolite catalyst. Most reported zeolite catalysts containing Pt are those in which Pt is impregnated or ion exchanged outside the lattice of the zeolite (see P. Meriaudeau et al., Stud. Surf. Sci. And Catal., 49: 1423). (1989); BS Kwak et al., J. of Catal., 149: 465 (1994)), these catalysts were prepared once a bimetallosilicate catalyst was prepared, and then Pt was supported outside the lattice of the catalyst for catalytic activity. Although the increase and retention of Pt have been made, it has been pointed out as a problem that the dispersion degree of Pt is not uniform.

Meanwhile, Inui et al. Reported the only example in which Pt was supported inside the lattice of MFI zeolite catalyst, but they used a bimetallosilicate catalyst of H-Pt-Zn-Silicate or H-Pt-Ga-Silicate. T. Inui, et al., Appl. Catal. A: General, 106: 83 (1993); T. Inui, et al., Preprints of Petrol. Chem., ACS Annual Meeting, New York, Aug: 705, 25-30 (1991)). Since the electric H-Pt-Zn-Silicate or H-Pt-Ga-Silicate catalysts contain Pt inside the lattice, problems of conventional catalysts have been found in that the catalyst can be deactivated and the dispersion of Pt is improved. To some extent, however, the yield of aromatic hydrocarbons was only 40%, and it was necessary to increase the catalytic activity.

Accordingly, the present inventors have made efforts to develop a silicate catalyst containing Pt in the zeolite lattice to maintain high catalytic activity while improving the dispersion of Pt and the stability of the catalyst. The metal catalyst-supported trimetallosilicate catalyst was prepared, and the aromatic hydrocarbons were produced in high yield from the aromatization of aliphatic hydrocarbons using the electrocatalyst, indicating that the electrocatalyst has excellent catalytic activity and excellent stability. It confirmed and completed this invention.

After all, the main object of the present invention is to provide a trimetallosilicate catalyst comprising three metal components including Pt inside the zeolite lattice, which is useful for aromatization of hydrocarbons.

Another object of the present invention is to provide a process for producing aromatic hydrocarbons using an electric trimetallosilicate catalyst.

FIG. 1 is a graph showing the long-term operation results of the aromatization yield of 1-pentene by H-Pt-Ga-Al-Silicate and H-Ga-Al-Silicate catalysts.

FIG. 2 is a graph showing the long-term operation results of the aromatization yield of 2-pentene by H-Pt-Ga-Al-Silicate and H-Ga-Al-Silicate catalysts.

The trimetallosilicate catalyst of the present invention is prepared by simultaneously dropping three metals, including Pt, into the appropriate precursor forms in the silica precursor during the preparation of the zeolite catalyst, so that all metal components including Pt are supported inside the zeolite lattice. In the trimetallosilicate catalyst of the present invention, since Pt is supported inside the zeolite lattice, Pt has a good dispersion of the Pt, excellent stability of catalytic activity, and in addition to Pt, two other metals capable of promoting aromatization of hydrocarbons. At the same time, it shows high catalytic activity. When the trimetallosilicate catalyst of the present invention is used for the aromatization of aliphatic hydrocarbons, aromatic hydrocarbons can be produced in high yield.

Hereinafter, the present invention will be described in more detail.

The inventors added dropwise an aqueous solution containing both Pt and precursors of two other metals capable of promoting aromatization of hydrocarbons to a gel-type silica precursor in the initial stages of the zeolite catalyst preparation process, until a uniform state was achieved. After mixing well, a trimetallosilicate catalyst having a MFI structure was prepared in which all three metal components including Pt were supported in the zeolite lattice through a process such as templating, crystallization, and calcination. On the other hand, in a preferred embodiment of the present invention, a metal trimetal silicate catalyst comprising Al, Ga and Pt as a metal component was prepared, but two other metal components except Pt is not particularly limited as long as the object of the present invention is not impaired It is not, but is selected from the group consisting of Al, Ga, Ni, Cu, In and Zn. In the case of trimetallosilicate catalysts comprising Al, Ga and Pt, the content ratio of each metal component to Si is a molar ratio, wherein Si / Al is 50 to 1000, preferably 100 to 800; Si / Ga is 10 to 500, preferably 40 to 200; Si / Pt is 100 to 1000, preferably 200 to 400.

The aromatization reaction of 1-pentene and 2-pentene is carried out under the same conditions by using the trimetallosilicate catalyst of the present invention, the conventional monometallosilicate catalyst and the bimetallosilicate catalyst, and the reaction product by gas chromatography. As a result of the analysis, it was observed that the yield of aromatic hydrocarbons increased by 10% or more when the trimetallosilicate catalyst of the present invention was used, compared with the case of using an H-Pt-Ga-Silicate catalyst such as Inui. It was suggested that the catalyst of the present invention has excellent catalytic activity. In addition, the conventional Ga and Al-supported bimetallosilicate catalyst (H-Ga-Al-Silicate) exhibited catalytic activity comparable to that of the trimetallosilicate catalyst of the present invention, As a result of investigating the stability of the catalytic activity, it was confirmed that the stability of the trimetallosilicate catalyst of the present invention is extremely high, and when the trimetallosilicate catalyst of the present invention comprehensively considers catalytic activity and stability, It can be concluded that it has excellent characteristics.

According to the method for producing an aromatic hydrocarbon using the trimetallosilicate catalyst of the present invention, the pressure condition of 1 to 10 atm, preferably 1 to 5 atm, and most preferably 1 atm in a fine reactor using the catalyst of the present invention And under a temperature condition of 600 to 900 K, preferably 700 to 800 K, W / F is 1 to 50 g-cat · h / mol, preferably 5 to 20 g-cat · h / mol, most preferably 10 g-cat Aromatic hydrocarbons are prepared by carrying out the aromatization of aliphatic hydrocarbons using helium as the carrier gas while maintaining the reaction rate to h / mol.

Meanwhile, in a preferred embodiment of the present invention, 1-pentene and 2-pentene are used as the electric aliphatic hydrocarbons, but the type of aliphatic hydrocarbons used in the preparation of the aromatic hydrocarbons using the trimetallosilicate catalyst of the present invention is a is not particularly restricted so long as it does not inhibit the purpose, preferably olefin hydrocarbons and paraffin hydrocarbons, C ₂ to C _6.

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are only for illustrating the present invention in more detail, it will be apparent to those skilled in the art that the scope of the present invention is not limited to these examples.

Example 1 Preparation of H-Pt-Ga-Al-Silicate Catalyst

Ludox HS-20 (DuPont, USA), a silica precursor in gel form, was mixed well with water until uniform, and then Al (NO ₃ ) ₃ · 9H ₂ O gallium, an aluminum precursor, was used as a metal precursor. An aqueous solution containing a precursor of gallium nitrate (Ga (NO ₃ ) ₃ .XH ₂ O), 0 <X <1) and H ₂ PtCl ₆ , a platinum precursor, was added and mixed well until uniform. At this time, the molar ratio of each of the metal precursors in the electric mixture to the silica is as follows.

Si / Al = 100

Si / Ga = 40

Si / Pt = 200

TPABr aqueous solution was added to the electric mixture as a templating agent and mixed well. Then, an aqueous NaOH solution was added and mixed well, followed by stirring for 1 hour. The solution was then crystallized at autogenous pressure at 170 ° C. autoclave for 72 hours at autogenous pressure. The resulting crystals were filtered and washed several times with distilled water and dried at a temperature of 110 ℃. The dried crystals were calcined for 12 hours in an air atmosphere at 550 ° C., so that three metals, such as gallium, aluminum, and platinum, were simultaneously supported in the zeolite lattice, trimetallosilicate catalysts having an MFI structure, that is, H- Pt-Ga-Al-Silicate was prepared.

Example 2 Aromatization of Hydrocarbons with H-Pt-Ga-Al-Silicate Catalyst

Using H-Pt-Ga-Al-Silicate catalyst obtained from Example 1 above, 1-pentene and 2-pentene were reacted, respectively, at 1 atm, 773 K, W / The aromatization reaction was carried out using a helium-derived fine reactor in a condition of F = 10 g-cat.h / mol.

Subsequently, the conversion of 1-pentene and 2-pentene and the yield of aromatic hydrocarbon were measured by gas chromatography. As a result, the conversion of 1-pentene was 97.9%, the yield of aromatic hydrocarbon was 54.2%, the conversion of 2-pentene was 98.9%, and the yield of aromatic hydrocarbon was 55.0%, respectively.

Comparative Example 1 Aromatization of Hydrocarbons with Monometallosilicate Catalysts

An H-Ga-Silicate catalyst was prepared in the same manner as in Example 1, except that only Ga (NO ₃ ) ₃ .XH ₂ O (0 <X <1) was used as the metal precursor. Then, the aromatization reaction of 1-pentene and 2-pentene was carried out in the same manner as in Example 2 using the electric H-Ga-Silicate catalyst, and the conversion of pentene and the yield of aromatic hydrocarbons were measured. As a result, the conversion of 1-pentene was 94.5%, the yield of aromatic hydrocarbon was 44.0%, the conversion of 2-pentene was 93.5%, and the yield of aromatic hydrocarbon was 43.1%, respectively.

Comparative Example 2 Aromatization of Hydrocarbon by Bimetallosilicate Catalyst

[Comparative Example 2-1] Aromatization of Hydrocarbon by H-Ga-Al-Silicate Catalyst

H-Ga in the same manner as in Example 1, except that Al (NO ₃ ) ₃ .9H ₂ O and Ga (NO ₃ ) ₃ .XH ₂ O (0 <X <1) were used as the metal precursors. -Al-Silicate catalyst was prepared. Then, the aromatization reaction of 1-pentene and 2-pentene was carried out in the same manner as in Example 2 using an electric H-Ga-Al-Silicate catalyst, and the conversion of pentene and the yield of aromatic hydrocarbons were measured. As a result, the conversion of 1-pentene was 99.7%, the yield of aromatic hydrocarbon was 53.3%, the conversion of 2-pentene was 98.5%, and the yield of aromatic hydrocarbon was 55.2%, respectively.

[Comparative Example 2-2] Aromatization of Hydrocarbon by H-Ga-Zn-Silicate Catalyst

H in the same manner as in Example 2-1, except that Ga (NO ₃ ) ₃ .XH ₂ O (0 <X <1) and Zn (NO ₃ ) ₂ .6H ₂ O were used as the metal precursors. -Ga-Zn-Silicate catalyst was prepared. Then, the aromatization reaction of 1-pentene and 2-pentene was carried out in the same manner as in Example 2 using an electric H-Ga-Zn-Silicate catalyst, and the conversion of pentene and the yield of aromatic hydrocarbons were measured. As a result, the conversion of 1-pentene was 95.1%, the yield of aromatic hydrocarbon was 41.2%, the conversion of 2-pentene was 96.2%, and the yield of aromatic hydrocarbon was 40.5%, respectively.

Comparative Example 2-3 Aromatization of Hydrocarbon by H-Ga-Ni-Silicate Catalyst

In the same manner as in Example 2-1, except that Ga (NO ₃ ) ₃ .XH ₂ O (0 <X <1) and Ni (NO ₃ ) ₂ .6H ₂ O were used as the metal precursors. -Ga-Ni-Silicate catalyst was prepared. Then, the aromatization reaction of 1-pentene and 2-pentene was carried out in the same manner as in Example 2 using an electric H-Ga-Ni-Silicate catalyst, and the conversion of pentene and the yield of aromatic hydrocarbons were measured. As a result, the conversion of 1-pentene was 96.5%, the yield of aromatic hydrocarbon was 37.2%, the conversion of 2-pentene was 94.9%, and the yield of aromatic hydrocarbon was 36.1%, respectively.

[Comparative Example 2-4] Aromatization of Hydrocarbon by H-Ga-Cu-Silicate Catalyst

As precursors _{Ga (NO 3) 3 · XH} 2 O (0 <X <1) , and _{Cu (NO 3) 2 · XH} 2 O (0 <X <1) and the electric conducted except using Example 2 H-Ga-Cu-Silicate catalyst was prepared in the same manner as -1. Then, the aromatization reaction of 1-pentene and 2-pentene was carried out in the same manner as in Example 2 using an electric H-Ga-Cu-Silicate catalyst, and the conversion of pentene and the yield of aromatic hydrocarbons were measured. As a result, the conversion of 1-pentene was 98.2%, the yield of aromatic hydrocarbon was 35.6%, the conversion of 2-pentene was 95.8%, and the yield of aromatic hydrocarbon was 37.0%, respectively.

Comparative Example 2-5 Aromatization of Hydrocarbons by H-Ga-In-Silicate Catalyst

Example 2 Except for the use of Ga (NO ₃ ) ₃ XH ₂ O (0 <X <1) and In (NO ₃ ) ₃ · 5H ₂ O (0 <X <1) as the metal precursor, H-Ga-In-Silicate catalyst was prepared in the same manner as -1. Then, the aromatization reaction of 1-pentene and 2-pentene was carried out in the same manner as in Example 2 using an electric H-Ga-In-Silicate catalyst, and the conversion of pentene and the yield of aromatic hydrocarbons were measured. As a result, the conversion of 1-pentene was 95.4%, the yield of aromatic hydrocarbon was 38.5%, the conversion of 2-pentene was 97.1%, and the yield of aromatic hydrocarbon was 39.5%, respectively.

[Comparative Example 2-6] Aromatization of Hydrocarbon by H-Pt-Ga-Silicate Catalyst

H-Pt-Ga-Silicate in the same manner as in Example 2-1, except that Ga (NO ₃ ) ₃ .XH ₂ O (0 <X <1) and H ₂ PtCl ₆ were used as the metal precursors. Catalyst was prepared. Then, the aromatization reaction of 1-pentene and 2-pentene was carried out in the same manner as in Example 2 using an electric H-Pt-Ga-Silicate catalyst, and the conversion of pentene and the yield of aromatic hydrocarbons were measured. As a result, the conversion of 1-pentene was 95.2%, the yield of aromatic hydrocarbon was 44.1%, the conversion of 2-pentene was 96.1%, and the yield of aromatic hydrocarbon was 44.1%, respectively.

Table 1 and Table 2 below summarize the results of the above Examples and Comparative Examples.

From the results of Tables 1 and 2, it was confirmed that the catalytic activity for aromatization of hydrocarbons was improved by simultaneously supporting Ga, Al, and Pt on silica.

Example 3 Stability of H-Pt-Ga-Al-Silicate Catalyst Activity

In order to compare and analyze the stability of the H-Pt-Ga-Al-Silicate catalyst of the present invention and the conventional H-Ga-Al-Silicate catalyst which showed a relatively high yield in Comparative Example 2-1, 1-pentene and 2 While the aromatization of each of the pentenes was carried out for a long time, the yield of aromatic hydrocarbons over time was investigated. As a result, as shown in Figures 1 and 2, in the case of using the H-Pt-Ga-Al-Silicate catalyst of the present invention, the catalytic activity remained stable even after a long time reaction, resulting in a decrease in yield with time. It is fairly gentle and maintains a yield of over 40% even after 50 hours, whereas when H-Ga-Al-Silicate catalyst is used, the catalyst destabilizes rapidly with the passage of the reaction time, and the yield is almost 20% after 50 hours. It was confirmed that the level decreases. These results suggest that the H-Pt-Ga-Al-Silicate catalyst of the present invention has very good stability.

As described and demonstrated in detail above, the present invention provides a trimetallosilicate catalyst comprising Pt in a lattice useful for aromatization of hydrocarbons. The trimetallosilicate catalyst of the present invention has an improved dispersibility of Pt, shows excellent catalytic activity and stability against aromatization of hydrocarbons, and thus may be useful for preparing aromatic hydrocarbons from various hydrocarbons.

Claims (2)

In the zeolite lattice includes Al as 1/1000 to 1/50 Al, 1/500 to 1/10 Ga and 1/1000 to 1/100 Pt as molar ratio to Si. Useful trimetallosilicate catalysts (H-Pt-Ga-Al-Silicate). The catalyst of claim 1 is used to convey helium while maintaining the reaction rate such that W / F is 1 to 50 g-cat · h / mol under a pressure condition of 1 to 10 atm and a temperature of 600 to 900 K in a differential reactor. A method for producing a hydrocarbon comprising the step of aromatizing C ₂ to C ₆ olefinic or paraffinic hydrocarbons as a gas.