JPH0380137B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD OF THE INVENTION The present invention relates to a method for producing secondary alcohols. More specifically, the present invention relates to a method for producing a secondary alcohol using a di-secondary alkyl ether as a raw material. Conventional technology The technology related to the decomposition of alkyl ether is
Conventionally, research has been carried out as a method for producing isobutylene by decomposing methyl tertiary butyl ether, particularly methyl tertiary butyl ether. Although this is attracting attention as an advantageous industrial process for separating tertiary olefins and replacing the sulfuric acid extraction method, there is no mention of a method for producing secondary alcohols by decomposing secondary ethers. Decomposition of tertiary ethers can be carried out using a method using an activated carbon catalyst in the gas phase (Japanese Patent Publication No. 54-41564), a method using silica
A gas phase decomposition method using a catalyst obtained by calcining alumina at 700 to 1100°C (Japanese Patent Publication No. 60-21971), a method using an aluminum-containing silica catalyst (Japanese Patent Publication No. 1986-21971),
-85323), a method using a strong acid type ion exchange resin, etc., and the target products are a tertiary olefin and a primary alcohol. Problems to be Solved by the Invention It is known that di-secondary alkyl ethers are produced by dehydration condensation of secondary alcohols, reaction of di-secondary alkyl sulfates and secondary alcohols, and the like. When the decomposition of secondary ether is shown for di-secondary butyl ether (SBE), it is thought that it proceeds as shown in the following formula. SBE→SBA+C ₌₄ ...(1) SBA→C ₌₄ +H ₂ O ...(2) In order to obtain SBA (secondary butyl alcohol) with high selectivity, the reaction of the above formula (2) is preferable. do not have. In general, secondary ethers are more
Because of their low reactivity, high-temperature reactions are required with ordinary solid acid catalysts such as alumina, silica-alumina, magnesia, and activated clay. coking of the catalyst is likely to occur. On the other hand, ion exchange resins have high activity for ether decomposition reactions and can be used at temperatures below the resin's heat resistance temperature, but since the reaction of formula (2) above cannot be ignored, they are not necessarily suitable for highly selective production of SBA. Means for solving the problem Summary of the invention By decomposition of di-secondary alkyl ether, secondary
As a result of various studies on methods for producing high-grade alcohols with high selectivity, the present invention was completed by discovering that high-silica zeolite catalysts exhibit excellent activity. That is, the present invention provides a di-secondary alkyl ether, which is characterized by using a high-silica zeolite catalyst having a silica/alumina ratio of 10 or more when producing a secondary alcohol using a di-secondary alkyl ether as a raw material. Concerning the method of decomposing ether. High-silica zeolite catalyst The catalyst used in the present invention is a zeolite catalyst having a silica/alumina (molar ratio) of 10 or more. Particularly preferably silica/alumina (molar ratio) 20 to 500
mordenite, zeolite Y, and synthetic aluminosilicate. Mordenite Mordenite forms a 12-membered oxygen ring at the entrance of the main cavity, and in addition to existing naturally, it can be synthesized, and its silica/alumina (molar ratio) is 10, as shown by the following formula. 0.5-3.0M2 _{/o O.Al2O3.10SiO2.0-50H2O} [In the formula, _M is _an alkali metal or alkaline _earth metal, and n is the valence of the metal M. ] By treating such mordenite with an appropriate combination of dealkalization, acid extraction, and steam treatment, the silica/alumina (molar ratio) can be reduced to 20~20.
500 in the hydrogen form is preferably used. Dealkalization here means replacing some or all of the alkali metals or alkaline earth metals contained in mordenite with hydrogen ions, resulting in so-called hydrogen-type mordenite. Dealkalization is usually carried out by treating natural mordenite or synthetic mordenite with an aqueous solution of a water-soluble ammonium salt, such as ammonium chloride, ammonium nitrate, ammonium sulfate, ammonium acetate, etc. to convert the metal cations in mordenite into ammonium ions, and then calcination. This can be achieved by converting into the hydrogen form or by treating natural mordenite or synthetic mordenite with an acid, such as an aqueous solution of hydrochloric acid, sulfuric acid, nitric acid, etc., to exchange the metal cations in mordenite into hydrogen ions. However, hydrogen-type mordenite is commercially available and can be synthesized, so dealkalization is not necessarily necessary. The acid extraction treatment involves bringing the mordenite into contact with a mineral acid such as hydrochloric acid, sulfuric acid, nitric acid, or phosphoric acid, or an organic acid such as acetic acid or formic acid to extract alumina in mordenite.
Contact with the above acid is preferably carried out at 20 to 120°C for 1 to 100 hours. The acid extraction treatment may be performed two or more times. Note that this acid extraction treatment can also serve as the above-mentioned dealkalization treatment. It is desirable to reduce the alkali metal or alkaline earth metal in mordenite to 0.4% by weight or less as a metal oxide by dealkalization and acid extraction treatment. Steam treatment, which can be combined with acid extraction treatment, extracts mordenite from 150 to 150% in the presence of steam.
800℃, preferably 300-700℃, 0.5-50 hours,
The heat treatment is desirably performed for 1 to 30 hours. By the above method, the silica/alumina ratio can be adjusted to 20~
Setting the value to 500 produces a great effect in the present invention. The mordenite used in the present invention exhibits the X-ray diffraction pattern shown in Table 1 below.

[Table] As a preparation method for this catalyst, Journal of
Physical Chemistry Volume 80 (1976) Nos. 60-64
Page, JP 44-31948, JP 46-37166, JP 56-160316, JP 57-
Publication No. 108023, Japanese Patent Publication No. 164523, Japanese Patent Publication No. 1983-164523, Japanese Patent Publication No.
59-222431 to 222432, etc. Zeolite Y Zeolite Y is a phaujasite-based synthetic zeolite and forms a 12-membered oxygen ring. The catalyst used in the present invention is prepared by extracting and removing alkali metals or alkaline earth metals and aluminum contained therein from this zeolite Y to obtain the silica/alumina ratio described above. Dealalization and dealumination are accomplished, for example, by contacting silicon tetrachloride.
Specifically, zeolite Y is dehydrated at 300 to 500℃,
After drying, it is brought into contact with silicon tetrachloride vapor while raising the temperature from around room temperature. The final temperature is preferably 400-600°C. By doing this, dealkalization and the silica/alumina ratio can be increased, but in order to further increase the silica/alumina ratio, the acid extraction treatment described above may be combined with a steam treatment if necessary. The amount of alkali metals or alkaline earth metals in zeolite Y is desirably 0.4% by weight or less, and the use of silica/alumina ratios of 20 to 500 is particularly desirable as it is highly effective. The hydrogen type zeolite Y used in the present invention exhibits an X-ray diffraction pattern shown in Table 2 below. The zeolite is also called ultra-stable Y zeolite, and its preparation method is described, for example, in Journal of Catalysis, Vol. 46, pp. 100-106 (1977);
Vol. 285-288 (1978), etc.

【table】

[Table] Synthetic aluminosilicate (a) Synthetic aluminosilicate (a) has the general formula 0.7~1.1M _2/o O・Al ₂ O ₃・5~300SiO ₂・0~
40H ₂ O [However, M represents a metal cation, and n represents the valence of the cation. ], and the entrance of the main cavity forms a 10-membered oxygen ring or a 12-membered oxygen ring. Such crystalline aluminosilicates are known and can be prepared using, for example, aluminum compounds such as aluminum sulfate, silicon compounds such as sodium silicate, mineral acids such as sulfuric acid, and metal cations such as sodium chloride. It is obtained by heating and contacting a reaction mixture containing a salt, a cationic organic nitrogen compound such as tetrapropylammonium bromide, water, etc. Examples of such synthetic aluminosilicate (a) include ZBM-5, ZSM-11, which has a 10-membered oxygen ring at the main cavity entrance developed by Mobil Oil, and
ZSM-12, ZSM-23, ZSM-35, ZSM-38 and ZSM-4 whose main cavity entrance is a 12-membered oxygen ring,
Examples include ZSM-10, ZSM-20, ZSM-43, etc.
For example, ZSM-5 has an X-ray diffraction pattern shown in Table 3. Regarding these ZSM type aluminosilicates, the following United States patent (US) specifications,
Described in the British patent (GB) specification or published patent publication. ZSM-5 (US 3702886), ZSM-8 (GB
1334243), ZSM-11 (US 3709979), ZSM-12
(US 3832449), ZSM-23 (US 4076842), ZSM
−35 (US 4016245), ZSM−38 (US 4046859),
ZSM-4 (GB 1297256), ZSM-10 (US
3692470), ZSM-20 (US 3972983), ZSM-43
(Japanese Patent Publication No. 54-68800).

[Table] Each of the above synthetic aluminosilicate (a) is usually silica/alumina (molar ratio) as shown in the general formula above.
However, by changing the ratio of each reagent used during synthesis, it is possible to make the ratio even higher. Further, converting the synthetic aluminosilicate (a) into a hydrogen form can be easily achieved by dealkalization treatment and acid extraction treatment, as in the case of mordenite. Synthetic aluminosilicate (b) Synthetic aluminosilicate (b) has the general formula 0.8~1.5M _2/o O・Al ₂ O ₃・10~100SiO ₂・0~
40H ₂ O [However, M represents a metal cation, and n represents the valence of the cation. ], the entrance of the main cavity forms a 10-membered oxygen ring, and the X-ray diffraction pattern shown in Table 4 is shown.

【table】

[Table] This synthetic aluminosilicate (b) consists essentially of inorganic reactive materials and has the following composition expressed in the following molar ratio: SiO ₂ /Al ₂ O ₃ = 10-130, M _{2 /o} O /
_SiO2 =0.03~0.5, _H2O /M2 _/oO =100~1000,
X ⁻ /SiO ₂ =0.01 to 20 [However, M and n have the same meanings as above, and X ⁻ is an anion of the salt as a mineralizing agent. ) and heating and maintaining this reaction mixture at the crystallization temperature until crystals form (Japanese Patent Application Laid-Open No. 1983-1993).
It is specifically described in Publication No. 45111. ). By changing the ratio of each reagent used during preparation, the silica/alumina (molar ratio) of the general formula described above can be obtained arbitrarily, but to further increase the ratio, the same method as for mordenite can be used. Then, it may be subjected to acid extraction treatment or brought into contact with silicon tetrachloride as in the case of zeolite Y. Furthermore, it can be easily converted into a hydrogen form by dealkalization treatment and acid extraction treatment, as in the case of mordenite. Raw Material The raw material used in the present invention is di-secondary alkyl ether, but the concentration composition is not particularly limited as long as it is a fraction containing di-secondary alkyl ether. Di-secondary ethers, such as dibutyl ether, are produced as a by-product during the process of producing methyl ethyl ketone (MEK) from n-butene using the sulfuric acid method or the hydration method, and are released outside the system together with other by-products (dimers, etc.). present in the fraction that is purged. That is, in addition to the ether, an inert gas, paraffin, olefin, alcohol, aromatic compound, etc. may be contained. Note that it is preferable not to contain hydrocarbons such as dienes and acetylenes, bases, carbonyl compounds, and the like. Di-secondary alkyl ether is

[Formula] R ¹ , R ² , R ³ , and R ⁴ may be the same or different, and if the alcohol formed from an alkyl group having 1 to 6 carbon atoms is a secondary alcohol, it is branched. It's okay. Representative examples of the secondary ethers represented by the above general formula and secondary alcohols and olefins obtained from them are shown below. In general, ethers with a larger number of carbon atoms have higher decomposition properties. Reaction Conditions The present invention can be carried out in either a gas phase or a liquid phase, and can be carried out either continuously or batchwise. When the present invention is carried out in the gas phase, the temperature of the decomposition reaction is 50
-300°C, preferably 80-150°C. The reaction pressure may be as long as the secondary ether is a gas, but it is usually 0~
It is 50Kg/cm ² G. During the gas phase decomposition reaction, water vapor may or may not be present, and can be selected depending on the situation, but it is generally expected to be more effective in maintaining activity when the reaction is carried out in the presence of water vapor. That is, water is used in a H ₂ O/secondary ether (mol/mol) ratio of 0 to 50. The reaction time varies depending on the catalyst, reaction temperature, etc., but in the case of a continuous method, the secondary ether supply rate LHSV (hr ^-1 ) per volume of catalyst is 0.1 to 20, preferably 0.5 to 5. In addition, when carrying out in liquid phase, the decomposition reaction temperature is 50~
The temperature is 300°C, preferably 80-150°C. The reaction pressure may be any pressure that can maintain the liquid phase, and is usually 0 to 50
Kg/cm ² G. The reaction time (LHSV, hr ^-1 ) is
It is 0.1-20, preferably 0.5-5. Further, during the liquid phase reaction, an appropriate solvent can be selected and used, and water may be present. As a solvent, oxyacid or its derivative (γ-
butyrolactone, γ-oxybutyric acid, etc.), sulfone derivatives (sulfolane, 2-methylsulfolane), etc. are used. One preferred solvent is γ-butyrolactone. When γ-butyrolactone is used as a 30 to 90% by weight aqueous solution, selectivity for secondary alcohols is particularly improved. When carrying out the present invention continuously, a known fixed bed reactor is usually used, and adiabatic type, heat exchange type, multi-tubular external heating type, etc. can be used. The present invention is based on secondary alkyl ethers.
It is suitable for producing alcohols with high selectivity, but the olefins produced at the same time are also useful chemical raw materials. Therefore, if olefin is required as well as secondary alcohol, the ratio of produced alcohol to olefin can be adjusted as appropriate. For example, increasing the reaction temperature will improve the yield of olefin. However, if it is increased further, the polymerization of olefin,
The conditions are chosen in each case, since coking etc. on the catalyst occur. The reaction product can be separated and recovered by a known method described in Japanese Patent Publication No. 60-21971. Effects of the Invention By decomposing di-secondary alkyl ether in the presence of a high-silica zeolite catalyst, secondary alcohol can be obtained with higher selectivity than known catalysts for decomposing tertiary ethers. Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto. In the text, the conversion rate of di-secondary alkyl ether,
and the selectivity of secondary alcohol are defined as follows. Di-secondary ether conversion rate (%) = (1-di-secondary ether (mol) in product/di-secondary ether (mol) in feed) x 100 Secondary alcohol selectivity (mol%) = (Secondary alcohol in the product (mol) - Secondary alcohol in the feed (mol) / Secondary ether in the feed (mol) - Di-secondary ether in the product (mol)) x 100 The catalysts used in the examples and comparative examples will be explained below. Catalysts A to D and F are 1/16 inch Extrudate, Catalyst E is a spherical product, Catalyst G
In ~J, the powder was compression molded and the powder had a particle size of 20 to 40 mesh after pulverization. Catalyst A: Synthetic mordenite (manufactured by Norton, USA)
Add 10% by weight ammonium chloride aqueous solution to 1g of mordenite (trade name: Zeolon 900Na),
15 c.c. was added and stirred at 80°C for 1.5 hours to separate the aqueous solution. Repeat this operation 3 times, thoroughly wash the mordenite with water, dry it at 120℃, and then dry it in air at 500℃ for 3 times.
Time-calcined Na ₂ O content 0.4% by weight, silica/
Hydrogen type mordenite (catalyst A) with an alumina molar ratio of 10 was prepared. Catalyst B: Add 1g of 12N hydrochloric acid to the above catalyst A.
Add 15c.c. per bottle, treat at 90℃ for 20 hours, remove the aqueous solution, wash thoroughly with water, dry at 120℃, and leave in the air.
A hydrogen-type mordenite (catalyst B) having a Na ₂ O content of 0.1% by weight and a silica/alumina molar ratio of 31 was prepared by firing at 700° C. for 3 hours. Catalyst C: The above catalyst A was treated with air containing 10% by weight of water vapor at 700°C for 3 hours (steam treatment), and then
Treat with sufficient 12N hydrochloric acid at 90℃ for 10 hours, remove the aqueous solution, wash with water, and dry at 120℃.
A hydrogen-type mordenite (catalyst C) having a Na ₂ O content of 0.08% by weight and a silica/alumina molar ratio of 104 was prepared by firing at 700°C. Catalyst D: Using the above catalyst C, the same steam treatment and 12N hydrochloric acid treatment as above were repeated three times.
A hydrogen-type mordenite (catalyst D) with a Na ₂ O content of 0.03% by weight and a silica/alumina (mole ratio) of 201 was prepared. Catalysts A to D prepared in this manner show the same X-ray diffraction pattern and no change in mordenite structure. Catalyst E: As a macroporous cation exchange resin (catalyst E), Amberlyst 15 (trade name, manufactured by Rohm and Haas) was used. Catalyst F: Silica-alumina manufactured by JGC Chemical under the trade name N632-HN was used. The silica/alumina (mole ratio) is 5. Catalyst G: TSZ-351 (trade name, manufactured by Toyo Soda Kogyo Co., Ltd.) (silica/alumina (molar ratio) = 6) was used as the ultra-stabilized Y-zeolite. Catalyst H: Add 1N hydrochloric acid to catalyst G at 5% per 1g of catalyst.
cc was added and treated at 80℃ for 3 hours, the aqueous solution was separated, washed with water, dried at 120℃, and prepared in air at 600℃ for 3 hours.Na ₂ O content 0.3% by weight, silica/alumina (molar ratio) = 33. An ultra-stabilized Y zeolite (catalyst H) was prepared. Catalyst I: Catalyst H except that 2N hydrochloric acid was used for catalyst G
An ultra-stabilized Y zeolite (Catalyst I) with a Na ₂ O content of 0.2% by weight and a silica/alumina (molar ratio) of 73 was prepared using the same method as in Example 1. Catalyst J: ZSM-5 zeolite was prepared according to the method described in US Pat. No. 3,965,207. That is, an aluminum sulfate solution was prepared by adding 7.4 parts by weight of sulfuric acid, 17.8 parts by weight of tetrapropyl aluminum bromide, and 86 parts by weight of sodium chloride to 195 parts by weight of pure water. This aluminum sulfate solution was mixed with 142 parts by weight of water and 281 parts by weight of No. 3 water glass (Na ₂ O
9.5%, SiO ₂ 28.6%) and mixed with stirring. The resulting mixture was transferred to a stainless steel autoclave and heated and maintained at 160° C. for 20 hours while stirring. The crystallized solid product was washed with water, dried at 120°C, and then calcined in air at 600°C for 3 hours. The X-ray diffraction pattern of the obtained solid showed a ZSM-5 crystal structure. This ZSM-5 was treated with a 1N ammonium chloride solution, ion exchanged, and fired to reduce the Na ₂ O content to 0.1.
%, hydrogen type with silica/alumina molar ratio 111
ZSM-5 (Catalyst J) was prepared. Examples 1 to 7, Comparative Examples 1 to 3 A tubular reactor was charged with 6 c.c. of catalyst, and a di-sec-butyl ether fraction [86% by weight of di-sec-butyl ether (SBE), sec-butanol ( SBA)1
% by weight, 13% by weight of octene] and brought into contact with each other under normal pressure and under the conditions shown in Table 1.

[Table] A known cation exchange resin catalyst (Catalyst E) has a high conversion rate, but the selectivity to SBA is extremely low. Furthermore, when the silica/alumina ratio is low (less than 10) like Catalyst F and Catalyst G, both the conversion rate and selectivity are insufficient. Examples 8 to 10 The same catalysts C and 6 c.c. as in Example 3 were charged into a tubular reactor, and a di-sec-butyl ether fraction (di-sec-butyl ether 88% by weight, sec-butanol 1% by weight) , 11% by weight of octene) was fed, and the amount of water added was varied, and contact was made under normal pressure. The results are shown in Table 2.

[Table] Example 11 Using the same catalyst C and 6c.c. as in Example-3, the purity was 98.
A similar test was conducted using % diisopropyl ether (IPE) as feed. The results are shown in Table 3.

[Table] Examples 12-20 Add 50 ml of di-secondary butyl ether fraction (88% by weight of SBE, 1% by weight of SBA, 11% by weight of octene) and 150ml of γ-butyrolactone (GBL) aqueous solution to an autoclave filled with 5g of catalyst at 150°C. The liquid phase reaction was carried out at autogenous pressure for 5 hours. The results are shown in Table 4.

[Table] Example 21 A di-secondary butyl ether fraction (86% by weight of SBE, 1% by weight of SBA, 13% of octene) and an aqueous solution of γ-butyrolactone at a concentration of 80% by weight were continuously added to a tubular reaction tube filled with 5 g of catalyst C. Supply 150℃, 45
The contact was carried out under the following conditions: Kg/cm ² G, LHSV = 4 (hr ^-1 ), and H ₂ O/SBM molar ratio = 4.5. 50 hours after the start of the reaction, the SBE conversion rate was 48.9% and the SBA selectivity was 81.3 mol%.

Claims (1)

[Claims] 1 Using di-secondary alkyl ether as a raw material,
When producing grade alcohol, the silica/alumina ratio
A method for decomposing di-secondary alkyl ether, characterized by using a high silica zeolite catalyst of 10 or more.