JPS6065714A - Zeolite containing iron-titanium-various kinds of metals, and catalyst containing it as active ingredient - Google Patents

Abstract

PURPOSE:The titled catalyst capable of controlling distribution of number of carbons of reaction product, having high activity, and high ratio of olefin in the reaction product, obtained by subjecting a mixture of an iron source, a Ti source, and sources of various kinds of metals to hydrothermal synthesis. CONSTITUTION:A silica source (e.g., water-glass) is blended with an iron source (e.g., FeSO4), a Ti source (e.g., TiCl4), sources (M) of various kinds of metals such as V, Mn, Zn, Sr, Mo, etc., an alkali metal ion source, and a tetraalkyl ammonium source (R4N<+>) to make molar ratio of Si/Fe of >=2, Ti/Fe of 0.01-3, M/Fe of 0.01-3, H2O/SiO2 of 30-70, R4N<+>/SiO2 of 0.08-0.16, OH<->/SiO2 of 0.07-0.3. The prepared aqueous mixture is subjected to hydrothermal synthesis at normal pressure or pressure of the mixture of its own at 90-200 deg.C for 10- 200hr, to give a catalyst comprising crystalline silicate containing iron-titanium- various kinds of metals as an active ingredient.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel iron-titanium-various metal-containing crystalline silicate and a catalyst for synthesizing hydrocarbons from a mixed gas of carbon monoxide and hydrogen containing the same as an active ingredient. .

Traditionally, the method of producing hydrocarbons by reacting carbon monoxide and hydrogen in the presence of a catalyst is the Fischer
This is known as Tropsch synthesis, and is a catalytic reaction in which co and 142 form a c-c bond, as shown in the following formula.

Co + 2 H2→n + cH2+ n +, H2
0 In this Fischer-Tropsch synthesis, CO
Since it does not undergo hydrogenation, it undergoes polycondensation,
Depending on the type of catalyst and reaction conditions, the value of n in the above formula, i.e.,
The C-C polymerization degree of the products varies, and the types of products include olefins and paraffins, as well as aldehydes and ketones, which are incomplete products of hydrodehydration.

In Fischer-Tropsch synthesis, iron-based catalysts are generally employed, and when a trace amount of alkali metal salt is added, a product with a significantly increased degree of C-C polymerization is obtained.
It has the drawback that it is extremely difficult to control the carbon number distribution of the product, and improving this drawback is the biggest technical challenge in Fischer-Tropsch synthesis.

On the other hand, among the various solid inorganic compounds used in catalysts, in porous materials, the area of the inner walls of the pores is several tens to hundreds of times larger than the outer surface, so most of the active sites of the catalyst are located inside the pores. it is conceivable that. Therefore, if the pore size of the catalyst is appropriate, there will be both molecules that are too large to fit into the pores and molecules that can fit into the pores, and molecules that cannot enter will have a much smaller chance of reacting than molecules that can. Become. As for the product, molecules larger than the pore are not produced within the narrow pore. In this way, the relationship between pore structure and molecular shape determines the selectivity of a catalyst, and zeolite is one such catalyst. Zeolite is generally a crystalline aluminosilicate, and is a porous crystal in which (S'Oz) and (Alo□)- are combined three-dimensionally. They have the same size and are suitable as molecular shape selective catalysts.

From this point of view, it is possible to combine a Fischer-Tropsch synthesis catalyst with zeolite. (p, l), Caesar, J.A.

13rennan, W. E., Qarwood, J.
C1tio, J., Catal.

56, 274 (1979); V, U, S,
Rao, L.J., Qormley Hydrocarb
on Proceeding, NOV, l 39 (
1! l 80) +E, P, 20140.20141
;U, S, I', 4298695.

4269784) However, the previously proposed combinations of Fischer-Tropsch synthesis catalysts and zeolites involve simply mixing the two or simply impregnating and supporting the active components of the Fischer-Tropsch catalyst on the zeolite. In terms of carbon number distribution control, satisfactory results have not yet been achieved. In addition, recently, Fe, Ni, i'i, Ru
, Rh and other crystalline metal silicates have been synthesized and attempts have been made to use them as Fischer-Tropsch synthesis catalysts;
50525 Al: JP-A-56-96720; JP-A-Sho 5
7-183316: JP-A-57-183317; JP-A-57-183320: JP-A-58-74521L In this case, although some improvement can be seen in controlling the carbon number distribution of the product, it is still insufficient. I can't say that.

Furthermore, the proportion of olefin in the product is small, making it insufficient as a catalyst for lower olefin synthesis.

The present inventors have solved the above problems found in the prior art,
As a result of intensive research aimed at developing a catalyst that makes it possible to control the carbon number distribution of the product, has high activity, and has a large proportion of olefins in the product, we have found that iron sources, titanium sources, and various metal sources have been developed. Iron hydrothermally synthesized using a mixture
It was discovered that titanium-various metal-containing crystalline silicates are suitable for this purpose, and the present invention was completed.

The iron-titanium-various metal-containing crystalline silicate of the present invention is formed using a mixture of an iron source, a titanium source, and various metal sources when synthesizing crystalline silicate according to a conventionally known hydrothermal synthesis method. be.

As mentioned above, the crystalline metal silicate itself is well known, but in addition to iron and titanium, it also contains V and Mn as a third component.
, a mixture containing metal compounds such as Sr is used.

The iron-titanium-various metal-containing crystalline silicate of the present invention is
silica source according to conventionally known methods.

It is produced by subjecting an aqueous mixture consisting of iron sludge, a titanium source, various metal sources, and an alkali metal ion source to a hydrothermal synthesis reaction. In this case, the reaction aid may be, for example,
Conventional organic compounds such as various tetraalkylammonium compounds can be used. As a silica source, water glass, silica gel, silica sol or silica is used. Iron sources include ferrous sulfate, ferrous chloride, and ferric sulfate.
Iron, ferric chloride, etc. are used. As the titanium source, titanium oxysulfate, titanium sulfate, titanium tetrachloride, etc. are used. As the alkali metal ion source, sodium oxide in water glass, alumina soda, sodium hydroxide, potassium hydroxide, etc. are used. Various conventionally known organic compounds such as tetraphosphonium compounds, tetraalkyl compounds, ethylenediamine, choline, etc. can be used as reaction aids, but tetraalkylammonium compounds are preferred, and among them, tetraalkylammonium bromide is particularly preferred. preferable.

When producing the iron-titanium-various metal-containing crystalline silicate of the present invention, the raw material reaction mixture generally preferably has the following composition.

Si/re' (molar ratio): 2 or more Ti/Fe (〃 ) 2001~3 M/Fe (p): 0.01~3 H20/5iO2 (〃): 30~7゜11.4N+/5io2 (''): 0.08~0.
160H/Sin□(〃): 0.07 to 0.3 Here, OH- indicates the amount of hydroxide ions in the mixture, and an alkali metal hydroxide, an alkali metal oxide, etc. are used to adjust this value. R4N+ indicates the amount of tetraalkylammonium ion. Also, M is V.

Indicates various metals such as Mn, Zn, Sr, and Mo.

An aqueous gel mixture having such a component composition is maintained under conditions of temperature, pressure, and time under which ordinary crystalline silicate is produced, and hydrothermal synthesis is carried out. In this case, the reaction temperature is 90-200
"C1" is preferably 95 to 170"C, and while the reaction mixture is refluxed under normal pressure, hydrothermal synthesis is carried out by heating and stirring for 10 to 200 hours under autogenous pressure in a closed container. By carrying out this process, iron-titanium-various metal-containing crystalline silicate can be obtained. The reaction product is processed by filtration or centrifugation to separate solids from the aqueous solution.

(I) The solid material obtained is further washed with water to remove excess ionic substances, and then dried to form iron-titanium-various metal-containing crystalline materials containing organic compounds used as reaction aids. Silicates can be obtained. By calcining this material in air at a temperature of 300 to 900°C, preferably 400 to 700°C for 1 to 100 hours, iron-titanium-various metal-containing crystalline materials containing no organic compounds can be obtained. Silicates can be obtained.

The iron-titanium-various metal-containing crystalline silicate of the present invention is usually used as a catalyst in the form in which the organic compound used as a reaction aid has been removed.
Various metal-containing crystalline silicates can also be used by replacing the alkali metal ions contained as cations with other cations. The iron-titanium-various metal-containing crystalline silicate of the present invention is used as a catalyst for synthesizing hydrocarbons using a mixed gas of carbon oxide and hydrogen as a raw material, that is, as a catalyst for Fischer-Tropsch synthesis. In this case, conventionally known conditions are adopted as the Fischer-Tropsch synthesis reaction conditions, for example, the reaction temperature is 2.
00 to 500°C, preferably 300 to 450°C, and the reaction pressure is 1 to 100 atm, preferably 10 to 50 atm. H2/ in raw material mixed gas
The Co molar ratio is 0.2-3, preferably 0.5-1.

The iron-titanium-various metal-containing crystalline silicate of the present invention can be advantageously used as a catalyst for Fischer-Tropsch synthesis reactions, and can also be used in various other reactions using zeolites as catalysts, such as converting hydrocarbons from methanol or dimethyl ether. In addition to synthesis reactions, hydrocarbon decomposition reactions, olefin polymerization reactions, hydrogenation reactions of organic compounds, aromatic alkyl reactions, Putoru.

Next, the present invention will be explained in more detail with reference to Examples.

Examples 1 to 6 Colloidal silica (catalyst chemical synthesis if'l, Cataloi
dS1-30), ferrous sulfate heptahydrate, titanium oxysulfate dihydrate, various metal compounds, potassium hydroxide (pure i8
A homogeneous aqueous gel-like mixture containing tetra-n-propylammonium bromide (5%), tetra-n-propylammonium bromide, and water in the composition shown in Table 1 below was placed in a sealed container and heated under one-sided pressure at 150°C for 40 hours. Stirred. The reaction mixture was centrifuged to separate solids, washed with water until free of ionic substances, dried at 100°C, and then incubated at 500°C for 15 minutes.
After firing for a period of time, a crystalline silicate containing iron, titanium, and various metals was obtained. The X-ray diffraction patterns of all of these were found to be substantially identical to that of Mopil's ZSM-5 zeolite. Also, that +3 E I
l+surface area is approximately 300m/,! ? Met.

Examples 8 to 14 The iron-titanium-various metal-containing crystalline silicate fired bodies obtained in Examples 1 to 7 were compressed into tablets at a pressure of 400 kg/cIn2, and then crushed into 15 to 30 meshes. Fill a reaction tube with an inner diameter of 20 mm with 20 mg of the
7't. Hydrogen treatment was performed at a rate of 10Qml/min at 400 to 500°C for 15 hours, and then the hydrogen was changed to a mixed gas of carbon monoxide and hydrogen (molar ratio 1:1).QH8V-10
The reaction was carried out at 25°C intervals from 300 to 450°C for 00 hr. Analysis of the product was performed using a gas chromatograph using argon as an internal standard. Table 2 shows the reaction results. Note that the conversion rate and selectivity shown below are both based on carbon, and the selectivity was calculated by setting the CO conversion rate excluding the conversion to CO2 (CO2 yield) as 100.

As can be seen by comparing this reaction result with those in Table 2 above, it is clear that iron-titanium-various metal-containing crystalline silicate is superior as a Fischer-Tropune synthesis catalyst, especially as a lower olefin synthesis catalyst. It is.

Claims (1)

[Claims] (1) An iron-titanium-various metal-containing crystal formed by a hydrothermal synthesis reaction using a mixture of an iron source, a titanium source, and various metal (V, Mn, Zn, Sr, MO, etc.) sources (2) A catalyst for synthesizing hydrocarbons from a mixed gas of carbon monoxide and hydrogen, characterized by containing the iron-titanium-various metal-containing crystalline silicate as an active ingredient.