JP7220447B2 - Catalyst for producing hydrocarbons from oxygen-containing organic compounds and method for producing hydrocarbons using said catalyst - Google Patents

Description

The present invention relates to a catalyst for producing hydrocarbons from oxygen-containing organic compounds and a method for producing hydrocarbons using the catalyst.

The use of fossil fuels causes massive emissions of carbon dioxide and contributes to global warming. On the other hand, fossil fuels such as petroleum have been used not only as energy sources but also as raw materials for synthesizing various organic substances. Securing raw materials for synthesizing organic substances will become an issue in the future due to global warming countermeasures and depletion of fossil resources. Therefore, it is required to synthesize organic substances from carbon resources that do not rely on fossil resources. Examples of alternative carbon resources include biomass and carbon dioxide, which basically have no danger of depletion and do not cause global warming.

Biomass gas obtained by heat-treating biomass is generally a mixed gas of carbon monoxide, carbon dioxide and hydrogen. Methanol can be produced by contacting this gas with, for example, a copper-based catalyst. Also, carbon dioxide can be reacted with hydrogen to synthesize methanol. In this way, methanol is a useful carbon material that does not rely on fossil resources or fossil fuels. Enables organic matter production as much as possible. Moreover, this methanol can be easily converted to dimethyl ether by a weakly acidic catalyst. On the other hand, the fermentation action of biomass produces ethanol and the like well. Therefore, the production of hydrocarbons, which are currently synthesized from fossil resources such as petroleum, from these oxygen-containing organic compounds, for example, methanol, dimethyl ether, ethanol, etc. It is in a chemical process that is free from risks. As a method for producing hydrocarbons, particularly olefinic hydrocarbons, which are raw materials for synthesizing organic substances from these oxygen-containing organic compounds, there is a reaction using an acid catalyst such as zeolite. This reaction is a dehydration reaction, and the oxygen in the oxygen-containing organic compound is desorbed together with the coexisting hydrogen by the strong acid of the zeolite and converted to hydrocarbons.

Microporous acid catalysts are often used in the production of lower olefin hydrocarbons such as ethylene and propylene from such oxygen-containing organic compounds. On the other hand, in recent years, silicoaluminophosphates such as SAPO are sometimes used. On the other hand, zeolite catalysts represented by H-ZSM-5 are already widely used in chemical processes and preparation methods have been established. be. However, compared with SAPO-34, zeolites have the problem that the yield of olefinic hydrocarbons such as ethylene and propylene is low.

As an attempt to improve the olefin yield by modifying zeolites such as H-ZSM-5 with silicon compounds, there is a method of depositing silicon alkoxide on the zeolite surface by chemical vapor deposition (Non-Patent Document 1). In this method, tetramethoxysilane (TMOS) is used as a silicon source for modification, and the zeolite surface is siliconized by decomposing it to form silicon oxide species, and an attempt is made to improve the olefin yield. However, although the yield of ethylene is about 1.8 times that of unmodified H-ZSM-5, the yield of propylene is only about 1.2 times higher.

Patent Document 1 relates to a catalyst for producing ethylene and propylene from methanol and/or dimethyl ether, and states that silicon modification of the catalyst is effective. silane and tetraethylsilane.

Patent Document 2 relates to a method for producing propylene from methanol or the like, in which a phosphate-based zeolite catalyst is modified with methoxytrimethylsilane or tetramethoxysilane.

US Pat. No. 5,300,003 discloses a method for preparing zeolites surface-modified with silicon alkoxides and then calcined.

On the other hand, Patent Document 4 discloses a catalyst for converting an oxygen-containing organic compound to an olefin, and as the catalyst, an MFI-type zeolite containing H-ZSM-5 is used with an alkyldisilazane, an alkylalkoxysilane, a haloalkylsilane, or the like. It is disclosed to be surface modified and then calcined.

As described above, the silicon compounds used to modify zeolites such as H-ZSM-5 with silicon have been investigated only as compounds with only one silicon atom as a substituent on the zeolite surface. Thus, no silicon compound has been investigated that can react with the zeolite surface at multiple reaction sites and contain multiple silicon atoms as substituents on the zeolite surface.

When modifying the zeolite surface, there are multiple silicon compounds in one molecule, and even after reacting with the zeolite surface, a compound in which multiple silicon compounds are present in one modification group is used. and zeolite (Patent Document 5). Thus, the zeolite is modified with a compound having a plurality of silicon atoms and having a plurality of silicon atoms in the substituents that modify the zeolite surface, and using such zeolites, the oxygen-containing organic compound as described above is There have been no examples of hydrocarbon synthesis of

Special table 2015-506824 JP 2012-020209 special table 2013-523582 special table 2017-507773 JP 2016-117029

M. Niwa, M. Kato, T. Hattori, Y. Murakami, J. Phys. Chem., 90, 6233-6237 (1986)

A main object of the present invention is to provide a technique for improving the synthetic yield of hydrocarbons, particularly olefinic hydrocarbons, from oxygen-containing organic compounds.

H-ZSM-5 etc. using an organic silane compound that contains multiple silicon atoms in one molecule and forms a substituent containing multiple silicon atoms even when the zeolite surface is modified By modifying the zeolite catalyst, it is thought that the pore size can be narrowed and the active sites on the outer surface can be eliminated. A zeolite system that can produce ethylene and propylene from oxygen-containing organic compounds remarkably compared to the same kind of unmodified zeolites by firmly modifying the surface of zeolites with atoms and, if necessary, performing heat treatment or calcination afterward. We succeeded in creating a catalyst and arrived at the present invention.

The present invention provides a catalyst for producing hydrocarbons from the following oxygen-containing organic compounds and a method for producing hydrocarbons using the catalyst.
Section 1. A catalyst for producing hydrocarbons from an oxygen-containing organic compound as a raw material, comprising zeolites modified with an organic polyvalent silane compound.
Section 2. A catalyst for producing hydrocarbons from an oxygen-containing organic compound as a raw material, comprising a zeolite modified with an organic polyvalent silane compound and calcined.
Item 3. The organic polyvalent silane compound has the following formula (I)

(In the formula, R ¹ and R ² are the same or different and represent H, OH, an alkoxy group, a vinyl group or a halogen atom. R ³ to R ⁶ are the same or different and represent an alkyl group or an alkoxy group. Y ¹ represents an organic linking group, and ^{R 1} to R ⁶ may be the same.)
3. The catalyst according to Item 1 or 2, which is a compound represented by:
Section 4. Item 4. The catalyst according to Item 3, wherein Y ¹ is an alkylene group or an arylene group.
Item 5. The organic polyvalent silane compound has the following formula (II)

(In the formula, Z is the same or different and is a vinyl group or a dimethylsiloxy group.)
3. The catalyst according to Item 1 or 2, which is a compound represented by:
Item 6. Item 6. A method for producing hydrocarbons, comprising the step of contacting the zeolites according to any one of items 1 to 5 with an oxygen-containing organic compound.
Item 7. Item 7. The method for producing hydrocarbons according to item 6, wherein the oxygen-containing organic compound is at least one selected from the group consisting of dimethyl ether, methanol and ethanol.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to synthesize hydrocarbons, particularly olefinic hydrocarbons, from oxygen-containing organic compounds in good yields. Examples of oxygen-containing organic compounds include lower alcohols (methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol), ethers (dimethyl ether, methyl ethyl ether, diethyl ether, diisopropyl ether), glycols (ethylene glycol, propylene glycol, glycerin, etc.), preferably methanol, dimethyl ether, ethanol, and the like. Hydrocarbons obtained from oxygen-containing organic compounds using the catalyst of the present invention include various organic compounds consisting of carbon and hydrogen (e.g. straight-chain or branched aliphatic saturated hydrocarbons, straight-chain or branched aliphatic unsaturated hydrocarbons). saturated hydrocarbons, olefinic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, polycyclic aromatic hydrocarbons, etc.), particularly olefinic hydrocarbons. Examples of olefinic hydrocarbons include ethylene, propylene, butylene, and isobutylene. In particular, propylene is an olefinic hydrocarbon that is feared that its supply will not keep up with demand, although it is important as a raw material for various chemical products and plastics.

An example of the relationship between the oxygen-containing organic compound used and the hydrocarbon obtained is shown in Table 1 below.

Zeolites modified with organic polyvalent silane compounds include A-type zeolite, L-type zeolite, X-type zeolite, Y-type zeolite, mordenite, beta-type zeolite, zeolites such as ZSM-5, and iron substituted for aluminum. iron silicate, copper silicate with copper substituted for aluminum, gallosilicate with gallium substituted for aluminum, borosilicate with boron substituted for aluminum, titanium substituted for aluminum Titanosilicates, vanadosilicates with vanadium substituted for aluminum, chromosilicates with chromium substituted for aluminum, zirconosilicates with zirconium substituted for aluminum, porous aluminophosphates with similar properties to zeolites It includes salts (eg SAPO-11 and SAPO-11-34) and the like. In one preferred embodiment, zeolites include aluminosilicates. Protons are most preferable as the cationic species that is the source of acid catalysts of zeolites, but there is no particular limitation as long as they are species capable of converting oxygen-containing organic compounds into hydrocarbons.

An organic polyhydric silane compound is a compound that contains a plurality of silicon atoms in one molecule and can bond with zeolites with a plurality of silicon atoms. The number of silicon atoms is 2 or more, preferably 2-16, more preferably 2-8, especially 2. As an organic polyvalent silane compound having 8 silicon atoms, an organic octasilane compound represented by the following formula (II) (cage-shaped silsesquioxane; POSS) can be exemplified. Examples of Z include a vinyl group and a dimethylsiloxy group. In the organopolysilane compound, each silicon atom preferably has a silicon-carbon bond and a substituent capable of reacting with functional groups on the surface of the zeolite or within the pores of the zeolite.

(wherein Z is as defined above)
R ¹ and R ² are groups capable of covalent bonding with functional groups (eg OH) on the zeolite outer surface or pore surface, such as H, OH, alkoxy groups (methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy , isobutoxy, sec-butoxy, tert-butoxy), vinyl groups, and halogen atoms (F, Cl, Br, I). Preferred substituents that react with the zeolite catalyst surface include hydroxyl groups (Si-OH), hydrogen groups (Si-H), vinyl groups (Si-CH=CH ₂ ), methoxy groups (Si-OMe), ethoxy groups ( Si-OEt) and the like can be exemplified.

Alkyl groups represented by R ³ to R ⁶ include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl.

Organic linking groups represented by Y ¹ include the following:

Silicon-carbon bonding sites include silicon-methyl group, silicon-ethyl group, silicon-propyl group, silicon-butyl group, silicon-phenyl group, silicon-tolyl group, silicon-biphenyl group and the like. Examples include silylbenzene and disilylbiphenyl groups. Preferred organic polyhydric silane compounds include compounds of formula (II) which are 1,4-bis(hydroxydimethylsilyl)benzene, 1,4-bis(dimethylsilyl)benzene, 1,4-bis(vinyldimethylsilyl)benzene and organic octasilane compounds. (For example, 1,3,5,7,9,11,13,15 ^- Okitavinylpentacyclo[ ^{9.5.1.13,9.15,15.17,13} ]octasiloxane) and the like can ^be exemplified.

The method of modifying the zeolite surface (outer surface, pore surface) with an organic polyvalent silane compound is not particularly limited, but the organic polyvalent silane compound is impregnated or adsorbed on the zeolite surface in a liquid or solution state, and then the zeolite surface and the A method of reacting, or a similar method in a solid state may be used. For example, when modifying an organic polyhydric silane compound, first, a solution of the organic polyhydric silane compound dissolved in an appropriate solvent is sufficiently blended with zeolite catalysts at room temperature or in a heated state. Although the time at this time is not particularly limited, it is preferably about 10 minutes to 3 hours, more preferably about 20 minutes to 2 hours. Although the temperature is not particularly limited, it is preferably about 10 to 60°C. Thereafter, the solid obtained by distilling off the solvent under reduced pressure may be heat-treated in that state. This heat treatment may be performed in an open system or in a closed container such as an autoclave. The heat treatment temperature at that time is preferably 80 to 300°C, more preferably 100 to 250°C, still more preferably 120 to 200°C. The heat treatment time is not particularly limited as long as the zeolite surface is sufficiently modified, but is preferably 10 to 200 hours, more preferably 20 to 100 hours. The modification amount of the organic polyvalent silane compound is not particularly limited, either. % by weight, more preferably about 5 to 15% by weight. A cleaning treatment using a solvent or the like may be performed after this modification treatment, but an additional treatment may not be performed. After that, calcination treatment in air may be carried out as required, at a temperature of 400 to 600°C, more preferably 450 to 550°C. The firing time is preferably 0.5 to 10 hours, more preferably 1 to 5 hours.

The conditions for the catalytic reaction using the modified zeolites thus obtained are also not particularly limited, but the conditions employed in many similar synthetic reactions may be followed. For example, the temperature ranges from 200 to 600°C, preferably from 250 to 550°C, more preferably from 300 to 500°C. The reaction pressure may be under pressurized conditions, but may be normal pressure. The method of supplying the raw material gas is also not particularly limited, but it may be an oxygen-containing organic compound alone or a mixture of an oxygen-containing organic compound and an inert gas. The ratio of the oxygen-containing organic compound at that time is also not particularly limited, but about 2 to 50% can be exemplified. In addition, the addition of substances other than inert gas may follow the conditions adopted in many similar synthetic reactions, for example, ethylene may be added.

EXAMPLES The present invention will be specifically described below by way of examples, but the present invention is not limited to these examples.

Example 1 Modification of Organic Disilane Compound to Zeolite HSZ-840HOA (SiO ₂ /Al ₂ O ₃ =40), an H-ZSM-5 catalyst manufactured by Tosoh Corporation, was calcined in the air at 500 ° C. for 2 hours, Surface adsorbed species were removed. Dissolve the prescribed amount of disilane compound [1,4-bis(hydroxydimethylsilyl)benzene] or 1,4-bis(vinyldimethylsilyl)benzene in 150 mL of acetone, and add 10 g of the above H-ZSM-5 catalyst to this solution. After stirring at room temperature for 30 minutes, acetone was distilled off under reduced pressure. The obtained powder was heat-treated at 150° C. for 3 days in a sealed glass flask. After that, the flask was opened and drying treatment was performed at 150° C. for 3 hours. For the 2%, 5%, 10% and 15% modified samples, 0.2 g, 0.5 g, 1.0 g and 1.5 g of organodisilane compound were used per 10 g of H-ZSM-5 catalyst, respectively.

Example 2 Modification of organooctasilane compound to zeolite In the same manner as in Example 1, the organooctasilane compound 1,3,5,7,9,11,13,15- ^{octavinylpentacyclo} [ ^{9.5.13,9.15 , 15.17,13} ]octasiloxane (manufactured by Sigma-Aldrich) was dissolved in 150 mL of acetone, 0.25 g of H-ZSM-5 catalyst used in Example 1 was added, and the mixture was stirred for 30 minutes at room temperature. Acetone was distilled off under reduced pressure. The obtained powder was heat-treated at 150° C. for 3 days in a sealed glass flask. After that, the flask was opened and drying treatment was performed at 150° C. for 3 hours.

Example 3 Calcining Treatment of Organosilane-Modified H-ZSM-5 Zeolite The organosilane-modified H-ZSM-5 zeolites obtained in Examples 1 and 2 were calcined in air using a muffle furnace. The temperature was raised from room temperature to 500°C at a rate of 5°C/min, treated at 500°C for 2 hours, and then allowed to cool naturally.

Example 4 Hydrocarbon production reaction from dimethyl ether using various H-ZSM-5 catalysts. A stainless steel catalyst reaction tube of about 1 cm was filled, nitrogen gas was flowed at a flow rate of 50 mL/min, and the reaction tube temperature was 150°C for 1 hour, 300°C for 1 hour, and 400°C for 3 to 4 hours. After treatment, a nitrogen-based 10% dimethyl ether mixed gas, which is a reaction gas, was flowed under normal pressure at a temperature of 400°C and a flow rate of 50 mL/min, and after a predetermined time had passed, the reaction gas was sampled. , reaction products, etc. were analyzed by on-line gas chromatography. Table 2 shows the evaluation results of catalytic activity.

As shown in Table 2, the zeolite catalysts modified with organodisilane compounds and organooctasilane compounds had higher propylene yield than H-ZSM-5 ( HSZ-840HOA ) that had not been modified, both calcined and non-calcined. rice field. In particular, the 10% modified catalyst more than doubled the propylene yield.

Example 5 Hydrocarbon Production Reaction from Dimethyl Ether Using Zeolite Beta Catalyst In the same manner as in Example 1, 10 g of Tosoh proton-type zeolite beta HSZ-931HOA (SiO ₂ /Al ₂ O ₃ =28) was used. Modified with 1 g of [1,4-bis(hydroxydimethylsilyl)benzene]. Using the catalyst thus obtained, the catalytic properties were evaluated in the same manner as in Example 4, except that the reaction temperature was 300°C. Table 3 shows the evaluation results of catalytic activity.

As shown in Table 3, zeolite beta modified with an organodisilane compound had a higher propylene yield than unmodified zeolite beta (HSZ-931HOA).

By using the modified zeolite catalyst of the present invention, lower olefin hydrocarbons such as ethylene and propylene can be produced in good yield from oxygen-containing organic compounds. Lower olefin hydrocarbons are raw materials for various chemical products and plastics. Oxygen-containing organic compounds such as methanol, dimethyl ether, and ethanol can be produced from carbon monoxide and hydrogen, carbon dioxide and hydrogen, or biomass. Therefore, it is possible to produce various chemical products and carbon-based products such as plastics from these oxygen-containing organic compounds.

Claims (4)

A catalyst for producing hydrocarbons from an oxygen-containing organic compound as a raw material, comprising zeolites modified with an organic polyvalent silane compound,
The organic polyvalent silane compound has the following formula (II)

(In the formula, Z is the same or different and is a vinyl group or a dimethylsiloxy group.)
A catalyst, which is a compound represented by A method for producing a catalyst for producing hydrocarbons using an oxygen-containing organic compound as a raw material, the method comprising the step of calcining a zeolite modified with an organic polyvalent silane compound,
The organic polyvalent silane compound has the following formula (II)

(In the formula, Z is the same or different and is a vinyl group or a dimethylsiloxy group.)
A manufacturing method, which is a compound represented by A method for producing hydrocarbons, comprising the step of contacting the zeolites according to claim 1 with an oxygen-containing organic compound. 4. The method for producing hydrocarbons according to claim 3 , wherein the oxygen-containing organic compound is at least one selected from the group consisting of dimethyl ether, methanol and ethanol.