JPH0310676B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing aromatic hydrocarbon mixtures from lower alcohols. More specifically, in a method for producing an aromatic hydrocarbon mixture from an alcohol having 4 or less carbon atoms per alkyl group, the aromatic hydrocarbon mixture is produced by contacting the alcohol with a special crystalline transition metal organosilicate. It is characterized by producing a mixture. Mixtures of aromatic hydrocarbons are widely used as gasoline. Generally it can be obtained by distillation of petroleum or conversion of heavier petroleum fractions, such as catalytic cracking, thermal cracking and hydrocracking. In order to improve the octane number of the hydrocarbon mixtures obtained in this way, the aromatic content is often increased by catalytic reforming. However, due to the recent rise in oil prices and oil shortages, there is an urgent need to develop technology for producing liquid fuels such as gasoline from resources other than oil. In this regard, the following new processes have recently been published: The process of gasifying natural gas, coal, etc. into a mixed gas of hydrogen and carbon monoxide, and then synthesizing methanol from this gas is a well-known technology, but a revolutionary process for synthesizing gasoline from this methanol has been patented in the US. 3894103 to 3894107. The feature of this process is that, unlike conventional zeolites, it uses a zeolite catalyst with a SiO ₂ /Al ₂ O ₃ ratio of 12 or more. There is a problem that several percent or more of ℃) is produced as a by-product. However, certain crystalline transition metal organosilicates, recently synthesized for the first time by the present invention, are suitable for use as catalysts for the production of aromatic hydrocarbon mixtures from lower alcohols, and are suitable for use as catalysts for the production of aromatic hydrocarbon mixtures from lower alcohols, and are suitable for use as catalysts for the production of aromatic hydrocarbon mixtures from lower alcohols, and are suitable for use as catalysts for the production of aromatic hydrocarbon mixtures from lower alcohols, and are suitable for use as catalysts for the production of aromatic hydrocarbon mixtures from lower _alcohols. The above-mentioned aromatic hydrocarbons were not produced, and as a result, an epoch-making result was obtained in which carbon production was suppressed and the catalyst life was extended. The method of the present invention is for producing an aromatic hydrocarbon mixture from an alcohol having 4 or less carbon atoms per alkyl group, at a reaction temperature of 300 to 600°C,
Expressed as molar ratio of oxide (dehydrated form) under reaction pressure of 100 atm or less and LHSV of 0.1 to 20 hr ^-1 , (0.1 to 2.0) R ₂ /nO・[aM ₂ O ₃・bAl ₂ O ₃ ]・ySiO ₂ {In the above formula, R: alkali metal ion, alkaline earth metal ion, organic ammonium ion and/
or hydrogen ion, M: one or more cations from the group consisting of iron, cobalt, rhodium, ruthenium, lanthanum, neodymium, titanium, vanadium, chromium, and antimony, a+b=1, a>0, b
0, y12}, and further contains an organic amine, an alcohol having 10 or less carbon atoms, an ether, a ketone, an ester, and/or an organic sulfur compound having 10 or less carbon atoms as an organic compound. It is characterized in that it is brought into contact with the crystalline transition metal organosilicate (hereinafter referred to as crystalline silicate) contained therein. Here, alcohols having 4 or less carbon atoms per alkyl group include methanol, ethanol, n-propanol, iso-propanol,
Examples include n-butanol, secondary butanol, isobutanol, and tertiary butanol, and one or more of these can be used as a mixture. The reason for limiting the reaction conditions is as follows. The reason why the reaction temperature is limited to 300 to 600℃ is because at a reaction temperature of 300℃ or lower, almost no alcohol reacts, and at a reaction temperature of 600℃ or higher, the rate of alcohol coking reaction and decomposition reaction into carbon monoxide and hydrogen increases. This is because the catalyst life is shortened. The reason why the reaction pressure is limited to 100 atm or less is that under a pressure of 100 atm or _more , the alkylation reaction of aromatic hydrocarbons proceeds too much, which causes problems when using it as gasoline as mentioned above. This is because the ratio of aromatic hydrocarbons increases rapidly, and even if the pressure is increased above the above-mentioned pressure, the conversion rate of the reaction does not increase and there is no advantage of increasing the pressure. The reason why the LHSV (liquid hourly space velocity) is limited to 0.1 to 20 hr ^-1 is because if the LHSV is less than 0.1 hr ^-1 , the throughput per catalyst capacity is too low and the efficiency is poor, and the proportion of aromatic hydrocarbons becomes large. This is because there is a problem that the contact time is too short, and when the LHSV is 20 hr ^-1 or more, the contact time is short and the methanol conversion rate is decreased. The crystalline silicate used in the present invention is synthesized from the following starting materials through a hydrothermal synthesis reaction. In this specification, the monovalent or divalent cation (R) refers to an alkali metal ion such as sodium or potassium, an alkaline earth metal ion such as calcium, or an organic ammonium ion. These are used as starting materials in the form of hydroxides, acids less strong than carbonic acid (eg aluminic acid, silicic acid, etc.), or halides. Also, iron, cobalt, rhodium, ruthenium,
The starting materials for transition metals such as lanthanum, neodymium, titanium, vanadium, chromium, and antimony are used in the form of sulfates, nitrates, chlorides, and the like. The silica source may be any silica source commonly considered for use in zeolite synthesis, such as solid silica powder, colloidal silica, or silicates such as water glass. The alumina source is most suitably sodium aluminate, but may also include aluminum salts such as chlorides, nitrates, or sulfates or alumina itself, preferably hydrated in the case of alumina. or in a form that can be hydrated, e.g. colloidal alumina,
boehmite, gamma alumina or alpha or beta trihydrate. Part or all of the alumina may be provided by the aluminosilicate compounds mentioned above with respect to the silica source. Starting materials for hydrothermal synthesis also include salts of lithium, sodium, and potassium with strong acids (e.g. chlorides,
A mineralizing agent (nitrate or sulfate) may be included, the cation of which should be chosen in harmony with the cation of the "alkaline component". As the organic compound added during synthesis, which is one of the characteristics of the crystalline silicate used in the present invention, the following can be used. (1) Alcohols alone or mixtures with ammonia Monoalcohols such as methanol, ethanol, t-butanol, etc. Diols such as ethylene glycol Triols such as glycerin, or mixtures of the above alcohols and ammonia, etc. (2) Organic amines n-propylamine, Primary amines such as monoethanolamine Secondary amines such as dipropylamine and diethanolamine, or tertiary amines such as tripropylamine and triethanolamine (3) Ether Ethyl ether, di-n-butyl ether, etc. (4 ) Ketones Diethyl ketone, diisobutyl ketone, etc. (5) Esters Ethyl acetate, isoamyl acetate, ethyl acrylate, etc. (6) Organic sulfur compounds (a) Thiols: methanethiol, 1-propanethiol, 1-butanethiol, etc. (b) Sulfide: Methyl sulfide, ethyl sulfide, etc. (3) Alkyl sulfone: Methylsulfon (d) Thiophene: Thiofene, tetrahydrothiophene, etc. (v) Sulfoxide: Methyl sulfoxide, ethyl sulfoxide, etc. (These various organic compounds are examples and are not included in this book. (The invention is not limited to these in any way.) The catalyst used in the present invention has a conventional zeolite structure in which part or all of Al is replaced with a transition metal, and also has a structure of SiO ₂ /( M ₂ O ₃ + Al ₂ O ₃ )
It is characterized by a ratio of 12 or more and is produced starting from an aqueous reaction mixture with the following molar composition. _SiO2 /( _M2O3 + _Al2O3 ) 12 _{~ 3000} (preferably 20~
200) _R2 /nO/ _SiO2 0.02~1.0 (preferably 0.05~
0.2) _H2O / _R2 /nO 10~1000 (preferably 50~
500 ₎ Organic compound/( _{M2O3 + Al2O3} 1-100 (preferably 5-50) _{M2O3 /} ( _{M2O3 + Al2O3 0.01-1} (preferably 0.05-1)
0.5) The crystalline silicate used in the present invention is synthesized by heating the raw material mixture at a temperature and time sufficient to generate crystalline silicate.
Hydrothermal synthesis temperature is 80~300℃ preferably 130~200℃
The hydrothermal synthesis time is from 0.5 to 14 days, preferably from 1 to 10 days. Although the pressure is not particularly limited, it is preferable to carry out the test under its own pressure. The hydrothermal synthesis reaction is continued by heating the raw material mixture to the desired temperature, with stirring if necessary, until crystalline silicate is formed. After crystals have thus formed, the reaction mixture is cooled to room temperature, filtered, washed with water, and the crystals are separated. Furthermore, it is usually 100℃
Drying is then carried out for about 5 to 24 hours. The crystalline silicate produced by the method described above can be used as a catalyst by well-known techniques, either as it is or by mixing it with a binder etc. that has been conventionally used for catalyst molding and molding it into an appropriate size. sell. Preferably, the crystalline silicate is activated by heating in air at a temperature ranging from 400 to 700°C for 2 to 48 hours before use as a catalyst. The alkali metal present in the crystalline silicate may be exchanged with one or more other cations by conventional methods to give the crystalline silicate in the H form or other metal cation form. Furthermore, this crystalline silicate is used for catalyst use.
It can be impregnated with compounds of more than one metal. Suitable metals include copper, zinc, chromium, lead, antimony, bismuth, titanium, vanadium, manganese, iron, cobalt, nickel, ruthenium, rhodium, palladium, platinum, lanthanum, or cerium. The impregnated silicate preferably contains 0.1 to 5.0 weight percent metal. The metal compounds used are suitably those which decompose on application of heat to give the corresponding oxides and which are soluble in water, such as nitrates or chlorides. The crystalline silicate is then impregnated with an aqueous solution of the compound of the desired metal and, by dry calcination, produces a metal oxide deposited in situ into the interstices of the crystalline silicate structure. As shown in the examples below, the catalyst obtained as described above can be used in conventional reactions for producing aromatic hydrocarbon mixtures from alcohols having 4 or less carbon atoms per alkyl group, such as methanol. It exhibits high catalytic activity not found in other catalysts. The present invention will be specifically explained below using Examples. Example 1 As an example of the crystalline silicate used in the present invention, synthesis was carried out by the method shown below. 112.5g of water glass (Na ₂ O・
Solution A was prepared by dissolving 3.4SiO ₂ .24H ₂ O). Then in a mixture of 192g water and 9.4g sulfuric acid 3.7
g of aluminum sulfate Al ₂ (SO ₄ ) ₃・16H ₂ O and
Solution B was prepared by dissolving 0.17 g of ferric sulfate Fe ₂ (SO ₄ ) _{3.9H 2} O. The above acids reduce the reaction mixture composition to the required level by neutralizing any excess alkali present.
It is in the Na ₂ O/SiO ₂ range. Finally, solution B was stirred and mixed into solution A (for 10 minutes), and 9.7 g of ethanol was added.
Inside a Teflon-lined stainless steel autoclave
The reaction was carried out at 180°C for 2 days with vigorous stirring. After cooling, the solid content is separated and the electrical conductivity of the cleaning solution is determined.
Wash until it becomes less than 100μ/cm, and then heat it at 110℃.
Dry for 12 hours. The crystal grain size of this product is about 1μ, and the composition excluding organic compounds is 0.7Na ₂ O・0.05Fe ₂ O ₃・0.95Al ₂ O ₃・75SiO ₂・
It was _19H2O . 1N crystalline silicate synthesized as above
It was immersed in hydrochloric acid and treated at 80°C for 7 days. this,
After washing and filtering, the product was compression molded and baked at 600°C for 3 hours, and then brought into contact with methanol under the reaction conditions shown below, and the following results were obtained.

[Table] As shown above, methanol can fully react under the above reaction conditions. Note that the higher the reaction temperature, the lower the LHSV, and the higher the reaction pressure, the more the proportion of aromatic hydrocarbons tends to increase. Example 2 The operation of Example 1 was repeated except that the following alcohol, organic amine, ether, ketone, ester, or organic sulfur compound was added in the same molar amount as the ethanol instead of the ethanol in Example 1. Prepare the silicate catalyst and store it at normal pressure 370℃, LH
The following results were obtained by contacting with methanol under the reaction conditions of SV1hr ^-1 .

[Table] Example 3 Example 1 except that instead of the ferric sulfate in Example 1, the following transition metal sulfate or chloride was added in the same molar amount as the ferric sulfate during hydrothermal synthesis. However, when adding a transition metal chloride, add hydrochloric acid instead of sulfuric acid to prepare a crystalline silicate catalyst ^.
The following results were obtained by contacting with methanol under the following reaction conditions.

[Table] Example 4 The crystalline silicate catalyst prepared in Example 1 was
Under the reaction conditions of normal pressure, 370℃: LHSV1hr ^-1 ,
When brought into contact with the alcohol shown below, the following results were obtained.

[Table] As shown in the examples above, by using the crystalline silicate of the present invention, aromatic carbonization that can be used as gasoline as is from alcohols having 4 or less carbon atoms per alkyl group, such as methanol. Hydrogen mixtures are obtained with very high selectivity. Furthermore, although the examples describe cases in which crystalline silicate is used alone, it goes without saying that it may be used in combination with a binder or the like conventionally used for catalyst molding.

Claims (1)

[Claims] 1. In producing an aromatic hydrocarbon mixture from an alcohol having 4 or less carbon atoms per alkyl group, the reaction temperature is 300 to 600°C and the reaction pressure is
Under conditions of 100 atm or less, expressed as the molar ratio of oxide (dehydrated form): (0.1 to 2.0) R ₂ /nO・[aM ₂ O ₃・bAl ₂ O ₃ ]・ySiO ₂ {In the above formula, R: Alkali metal ions, alkaline earth metal ions, organic ammonium ions and/or
or hydrogen ion, M: one or more cations from the group consisting of iron, cobalt, rhodium, ruthenium, lanthanum, neosium, titanium, vanadium, chromium, and antimony, a+b=1, a>0, b
0, y12}, and further contains an organic amine, an alcohol having 10 or less carbon atoms, an ether, a ketone, an ester, and/or an organic sulfur compound having 10 or less carbon atoms as an organic compound. 1. A method for producing an aromatic hydrocarbon, which comprises bringing it into contact with a crystalline transition metal organosilicate contained therein.