JPH0558918A - Bimetalosilicate catalyst for selective conversion of methanol to aromatic compound - Google Patents

Abstract

PURPOSE:To obtain an excellent catalyst for selectively synthesizing an aromatic hydrocarbon from methanol, consisting of an H-Fe-Zn-bimetalosilicate, especially H-Fe-Zn-bimetalosilicate modified with Pt or Pd. CONSTITUTION:An aqueous solution containing a metal salt having a composition shown in the table expressed by atom % (R is a quaternary alkylammonium cation, alkali metal is Na or K and Me is Fe or Zn), nitrogen-containing organic cation and inorganic acid, an aqueous solution of silicic acid salt and an aqueous solution of ion controlling agent are prepared, and then from these aqueous solutions by a quick crystallization method, an H-Fe-Zn-bimetalosilicate, especially, modified with Pt or Pd useful for selectively synthesizing an aromatic hydrocarbon from methanol is provided. When the catalyst is used, the ratios of oligomerization and aromatization of olefin produced are increased and the ratio of lower paraffins in the product is suppressed, and the product is relatively rich in a higher paraffin content and aromatic content, thereby occurrence of cokes is suppressed.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a catalyst for selectively synthesizing aromatic hydrocarbons from methanol.

[0002]

2. Description of the Related Art The subject of selectively synthesizing high octane gasoline or aromatic hydrocarbons from methanol is considered to be of ever increasing importance. Currently Mobile MTG
The process is operating with H-ZSM-5, but in this process it has to be operated under severe conditions of high temperature and medium pressure. It has the drawback that it needs to be recycled. Therefore, in order to overcome these problems, the present inventor has developed H, which has a high ability to convert paraffins to aromatics.
The -Ga-silicate catalyst was applied to the conversion of methanol to give a high octane gasoline rich in aromatics in a single pass at atmospheric pressure (T. Inui, H. Matsuda, et.a.
l. , Proc. 2nd Japan-Korea C
atal. , Symp. 19 (1989)). But,
There is a drawback that the deterioration due to the precipitation of coke is relatively fast due to the large amount of aromatics formed.

[0003]

[Purpose] The object of the present invention is to solve the above-mentioned drawbacks and to provide a catalyst having a high oligomerization of the produced olefin, almost no precipitation of coke, and a high aromatization ability.

[0004]

The present invention is based on H-Fe-Zn-bimetallosilicate or H-Fe-Z modified with Pt or Pd.
The present invention relates to a bimetallosilicate catalyst for selectively converting methanol into aromatics, which is composed of n-bimetallosilicate. The conversion reaction of the present invention is carried out by bringing the catalyst into contact with methanol gas or methanol gas diluted with an inert gas. If the device can control the exothermic reaction, it can be carried out without a diluting gas, but if the diluting gas is present, the reaction can be easily controlled. The catalyst of the present invention can be produced according to the rapid crystallization method previously proposed by the present inventor (JP-A-59-62349). The outline is as follows. Following general formula ^{(mol%) Si / Me 15~3500 OH -} / SiO 2 0.3~1.0 H 2 O / SiO 2 30~100 R / R + alkali metal 0.05 to 0.15 NaCl / H ₂ O 0.01 to 0.06 (wherein R is a quaternary alkylammonium cation, the alkali metal is sodium or potassium ion, and Me is Fe or Zn); When an aqueous solution containing a nitrogen-containing organic cation and an inorganic acid is A solution, an aqueous silicate solution is B solution, an ion adjustor aqueous solution is C solution, and when A solution and B solution are added to C solution at a constant rate, respectively, Ion modifier is added to solution A, and nitrogen-containing organic cation, inorganic acid and alkali hydroxide are added to solution C to reduce the concentration change of each solution composition. The first to integer 1
Crush the step and the gel mixture obtained from the first step,
The second step of subdividing, and the gel mixture obtained from the second step are heated from room temperature to 150 ° C. to 190 ° C. at a constant rate, and then further heated to 220 ° C. at a constant rate or an exponential function rate, and water is added. It comprises a third step of carrying out a thermosynthesis reaction. The atomic ratio of Fe to Zn in the catalyst of the present invention is 0.00
4 to 250, preferably 0.006 to 150, and S
The atomic ratio of Fe to i is 20 to 3500, preferably 25 to 3200, and the atomic ratio of Zn to Si is 15 to 3
It is 200, preferably 15 to 800. Further, the modification amount of Pt or Pd is 0.005 to 1.5, preferably 0.01 in terms of weight% with respect to the dry bimetallosilicate.
Is about 1.0.

[0005]

EXAMPLES Various metallosilicate catalysts were prepared by the rapid crystallization method described above. The Si / Fe and Si / Zn atomic ratios were all set to 400, and Fe-silicate (Comparative Example 1), Zn-silicate (Comparative Example 2) and Fe-Zn-bimetallosilicate (Example 1, corresponding to claim 1). ) 3
Different types were prepared. After washing, dry overnight at 120 ° C for 5
It was baked at 40 ° C. for 3.5 hours. It was ion-exchanged twice with a 1N aqueous solution of ammonium nitrate and baked to obtain an H-type. Pt
For modification, tetraamine dichloroplatinum was used to
After t ion exchange, Pt / H-Fe-silicate (Comparative Example 3), Pt / H-Zn-silicate (Comparative Example 4),
Pt / H-Fe-Zn-silicate (corresponding to Example 2 and Claim 2) was obtained. The obtained silicates were washed, dried, pyrolyzed, and then treated at 400 ° C. for 30 minutes in a 10 mol% hydrogen stream. Mold and crush, 8 to 1
The mixture was sieved to 5 mesh and used for the reaction. In the reaction, 20% methanol diluted with N ₂ was circulated at 350 ° C. and SV 2000 h ⁻¹ at atmospheric pressure by using a normal flow reactor. H
A comparison of the reaction products for the -Fe-Zn-bimetallosilicate catalyst (Example 1) is shown in Fig. 1. Pt
A comparison of reaction products for the / H-Fe-Zn-bimetallosilicate catalyst (Example 2) is shown in FIG. A comparison of reaction products of Pt / H-Fe-silicate catalyst (Comparative Example 3) is shown in FIG. In the figure, C ₂
= Represents ethylene, C ₃ = represents propylene, C ₄ = represents butylene, and C ₅ + represents paraffin having 5 or more carbon atoms. In Examples 1 and 2 of the present invention, oligomerization of lower olefins and aromatization of oligomers are advanced as compared with those of all Comparative Examples including Comparative Examples 1, 2 and 4 not shown, Moreover, the production of lower paraffin is significantly suppressed. In addition, H-Fe-Z
For the n-bimetallosilicate catalyst (Example 1),
In the case of Example 2 modified with Pt, the aromatic content gradually decreased as the distribution time increased, but the distribution time was about 5
Over time, almost consistent results were obtained.

[0006]

[Effect] The catalyst of the present invention has a higher ratio of oligomerization and aromatization of the produced olefin as compared with the Fe or Zn unit system, and the ratio of lower paraffins in the product is suppressed to be low. Was relatively high in paraffin and aromatics, and the generation of coke could be suppressed to a low level.

[Brief description of drawings]

FIG. 1 is a bar graph showing the product ratio for an H—Fe—Zn-bimetallosilicate-based catalyst (corresponding to claim 1).

FIG. 2 is a bar graph showing the relationship between the ratio of the Pt / H—Fe—Zn-bimetallosilicate-based catalyst (corresponding to claim 2) and the product with time.

FIG. 3 is a bar graph showing product ratios for conventional Pt-modified H-Fe-silicate based catalysts.

Claims (2)

[Claims] 1. A bimetallosilicate catalyst for the selective conversion of methanol to aromatics, which consists of H-Fe-Zn-bimetallosilicate. 2. H-Fe- modified with Pt or Pd
A bimetallosilicate catalyst for the selective conversion of methanol to aromatics, characterized in that it consists of Zn-bimetallosilicate.