JPH0987222A - Production of diisopropylether - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply and efficiently obtain diisopropylether especially useful as a gasoline base material in high conversion and high selectivity by dehydrating isopropyl alcohol in the presence of a solid superstrong acid catalyst. SOLUTION: This method for producing the diisopropyl ether comprises dehydrating (B) isopropyl alcohol (preferably having a purity of >=80%) in the presence of (A) a solid superstrong acid catalyst [preferably a catalyst produced by carrying a sulfate radical precursor on the hydroxide or oxide of the group III, IV or VIII metal in the periodic table and subsequently calcining the mixture, and having an acid strength expressed by the Hammett's function (Ho ):Ho <-11.9, especially Ho <-12.7]. The dehydration reaction is preferably performed at a temperature of 50-400 deg.C, especially 150-300 deg.C under the pressure of 1-200kg/cm<2> , especially 1-100kg/cm<2> , further especially 1-50kg/cm<2> .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a simple and efficient process for producing useful diisopropyl ether (hereinafter abbreviated as DIPE) from isopropyl alcohol, which is particularly useful as a high octane gasoline base material.

DIPE has a high calorific value, a low vapor pressure, a high research octane number (RON) of about 110, and a motor octane number (MON) of 99.
It is extremely high, is superior to other gasoline base materials, and has low sensitivity. The term “sensitivity” is commonly used in the art as a term that means the difference between RON and MON, and the smaller the sensitivity, the less likely knocking occurs at high speed. In view of these physical properties, DIPE is extremely useful as an oxygen-containing gasoline base material, and in view of the growing demand for oxygen-containing gasoline base material, it is expected that the demand for DIPE will further increase.

Further, an oxygen-containing organic compound such as DIPE improves the combustibility of hydrocarbon fuels, suppresses exhaust gas pollution such as NOx and the production of particulate matter such as soot, and is an additive for diesel fuel. Is also attracting attention.

[0004]

2. Description of the Related Art Conventionally, three methods of producing DIPE are known. That is, a method of directly hydrating water and propylene in a gas-liquid phase in the presence of a zeolite catalyst such as zeolite β, which is a zeolite catalyst developed by Mobil Co. (JP-A-1-246233), and isopropyl alcohol. A method of reacting with propylene (JP-A-52-131508), using an acidic ion exchange resin as a catalyst (JP-A-49-126607, JP-A-49-1171212, Texaco AG, Germany). , Or with sulfuric acid (US Pat. No. 4,471,471)
No. 142, Exxon), a method of obtaining DIPE produced as a by-product in the process of producing isopropyl alcohol from water and propylene.

However, in the synthesis method using a zeolite catalyst, the liquid space velocity (LHSV) is low because the activity of the catalyst is low.
Therefore, the amount of the raw material must be reduced relative to the amount of the catalyst, resulting in a high operating cost.

In addition, isopropyl alcohol is used to dip
As a method for producing E, a method using a sulfonic acid type acidic ion exchange resin (Journal of Japan Petroleum Institute, vol. 13, vol. 10)
No., p15, 1970) is known.

However, using this sulfonic acid type acidic ion exchange resin catalyst, D
The method for producing IPE not only requires a neutralization step with a basic substance because the sulfonic group of the ion-exchange resin is desorbed by water as a by-product at higher temperatures, but the desorption of the sulfonic group Catalytic activity tends to decrease. Further, there is a problem that coking is caused by the decomposition products of the by-products and the raw materials, which also causes the deactivation of the catalyst, and the DIPE yield is as low as about 5%. For this reason, there was no record of being industrially manufactured by this method.

Further, as mentioned above, water and propylene are often used as raw materials. However, when these are used as raw materials, side reactions such as a propylene polymerization reaction easily occur, or the reaction heat is large, so that it is difficult to control the reaction temperature (removal of reaction heat).

[0009]

Accordingly, the present invention finds that DIPE is useful, especially as a gasoline base stock.
It is an object of the present invention to provide a method capable of efficiently producing a compound by a simplified one-step method.

[0010]

Under such circumstances, the present inventor has studied various catalysts, and as a result, in the method for producing DIPE from isopropyl alcohol, the solid superacid catalyst is superior to other catalysts in comparison with other catalysts. The present invention has been completed based on the finding that DIPE can be easily and efficiently produced by a relatively simplified process by using high dehydration activity and this catalyst.

That is, the present invention provides a method for producing DIPE, which comprises etherifying isopropyl alcohol by a dehydration reaction in the presence of a solid superacid catalyst.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, it is preferable that the isopropyl alcohol used as a raw material does not contain an acidic substance that causes corrosion of the apparatus or a basic substance that becomes a catalyst poison. As the raw material isopropyl alcohol, not only isopropyl alcohol but also an isopropyl alcohol mixture can be used. The isopropyl alcohol mixture refers to a mixture containing normal propyl alcohol, a hydrocarbon having 2 to 4 carbon atoms, or the like in addition to isopropyl alcohol, or an isopropyl alcohol aqueous solution. In this isopropyl alcohol mixture, it is preferable that the isopropyl alcohol concentration is high. Isopropyl alcohol concentration is 50 wt% or more, especially 70 wt% or more,
Further, it is preferable that the amount is 80% by weight or more because the selectivity of DIPE increases. Of course, the method of the present invention can be carried out with an isopropyl alcohol mixture having an isopropyl alcohol concentration of less than 50% by weight if the problems such as selectivity are neglected.

Isopropyl alcohol and a mixture of isopropyl alcohol are prepared from water and propylene as raw materials, using a Texaco method in Germany (Hy
drocarbon Processing, Vol.51, No.11, p113, 1972
Year), Fever method using phosphoric acid catalyst (Hydrocarbon
Processing, Vol.46, No.11, p195, 1967), Tokuyama Soda method using hetropolyacid catalyst (Catalyst, Vol.18, No.6,
The product produced in p180, 1976) or the like can be used, but the production method is not limited in any way.

The solid super strong acid catalyst used in the present invention is obtained by impregnating the following carrier with a sulfate radical precursor. As the carrier, a metal of Group III, preferably Group IIIB of the Periodic Table (for example, aluminum, Examples include gallium, indium, and thallium, with aluminum being particularly preferred), Group IV metals (eg, titanium, zirconium, silicon, tin,
Hafnium and germanium are preferred, with titanium, zirconium, silicon and tin being particularly preferred) or VIII.
One or more metal oxides, metal hydroxides, complex metal hydroxides or complex metal oxides of a group I metal, preferably iron group metals (eg iron, cobalt, nickel are preferred, with iron being particularly preferred). Things can be used. The periodic table of elements used in the present specification was based on the one shown in the front cover of the Chemical Dictionary (1987) published by Morikita Publishing.
In the present invention, it is particularly preferable to use a composite metal hydroxide. The hydroxide impregnated and supported with the sulfate precursor is then converted into an oxide by firing.

Specific examples of such a carrier include alumina (Al ₂ O ₃ ), titanium oxide (TiO ₂ ), zirconium oxide (ZrO ₂ ), zirconia-alumina (ZrO ₂ .Al ₂ O ₃ ), zirconia. Ferric oxide (ZrO ₂ · Fe ₂ O ₃ ), zirconia
Examples thereof include gallium oxide (ZrO ₂ · Ga ₂ O ₃ ), zirconia / titania (ZrO ₂ · TiO ₂ ), zirconia / cobalt oxide (ZrO ₂ · CoO), and the like. The solid superacid is 1 to 10 parts by weight of a sulfate radical precursor (for example, sulfuric acid, based on 1 part by weight of the above-mentioned carrier, that is, the above-mentioned hydroxide or oxide.
Examples thereof include ammonium sulfate, ammonium hydrogensulfate, and sulfuryl chloride, with sulfuric acid, ammonium sulfate, and sulfuryl chloride being particularly preferable. ) And having a concentration of preferably 0.01 to 10 mol / l, particularly preferably 0.1 to 5 mol.
After treating with any suitable method such as immersing the carrier in a solution of 1 / l sulfate radical precursor, or passing the solution through the carrier, the solution is treated at a temperature of 400-
0.5 to 30 at 800 ° C, preferably 450 to 700 ° C
It can be obtained by firing for about an hour. However, the manufacturing method of the solid superacid is arbitrary and the present invention is not restricted by the manufacturing method.

The solid superacid used in the present invention has a surface area of 50 to 200 m ² / g and an acid strength of Hammett function (H
In o), it is preferable that Ho <−11.9, especially Ho ≦ −12.7. The Hammett function representing the acid strength used here is introduced in many books, but here, in particular, the New Experimental Chemistry Lecture, Volume 16, Reactions and Velocity, pages 210-226 of Maruzen Co., Ltd. It was The Hammett function can be measured using a Hammett indicator, a nitroaniline-based indicator, a nitrobenzene-based indicator, and the like, and specific indicators are shown on page 214 of the same book.

To produce DIPE by the method of the present invention,
Although isopropyl alcohol is reacted in the presence of the solid superacid as described above, the reaction system is not particularly limited, and fixed bed flow system, fluidized bed system, moving bed system, batch system, or any other suitable means is adopted. be able to.

When a fixed bed flow system is used, a carrier gas can be used, and an inert gas such as nitrogen, hydrogen, carbon dioxide gas, methane gas or the like can be used.

The reaction temperature is 50 to 400 ° C., especially 100 to
It is preferably 350 ° C., more preferably 150 to 300 ° C. If the reaction temperature is too low, the dehydration reaction of isopropyl alcohol does not proceed and DIPE is not produced. Further, if the reaction temperature is too high, the selectivity of the by-product by the polymerization reaction of propylene produced by the dehydration reaction of isopropyl alcohol becomes high, and not only the production of DIPE is suppressed, but also the produced water prevents the formation of sulfonic acid groups. Desorption will cause deactivation of the catalyst.

The reaction pressure is preferably 1 to 200 kg / cm ² , particularly 1 to 100 kg / cm ² , and more preferably 1 to 50 kg / cm ² . If the reaction pressure is too low, the reaction result is not good, and if the reaction pressure is too high, the wall pressure of the pressure resistant reactor made of an expensive material must be increased, resulting in an increase in cost.

In the case of the fixed bed flow type, the feed rate LH of the raw material
SV (h ^-1 ) 0.01 to 30, preferably 0.02 to 2
DIPE can be efficiently produced under the conditions of 0, more preferably 0.05 to 10. If the LHSV is too small, the amount of raw material with respect to the amount of catalyst must be reduced, resulting in higher operating costs. If the LHSV is too large, the amount of unreacted raw material increases and the recycling cost increases. In the case of a batch system, the amount of the catalyst used with respect to the raw material can be varied over a wide range, but generally speaking, 0.01 to 20 parts by weight, preferably 0.05 to 1 part by weight of the raw material.
The range is from 10 to 10 parts by weight, and more preferably from 0.1 to 5 parts by weight. The reaction time is 1 minute to 48 hours, preferably 10 minutes to 24 hours, and more preferably 1 hour to 12 hours.

There are various methods for recovering the produced DIPE after the reaction is completed, and the method is not particularly limited. Any appropriate method can be adopted depending on the purity and properties desired for the target product, the purpose of use, and the like. For example, the following method can be mentioned.

When the target product is a high-octane gasoline base material, the reaction recovery component flowing out of the isopropyl alcohol reactor is blended with the gasoline fraction in the extractor,
By recovering the obtained oil layer as high-octane gasoline, DIPE can be recovered as a gasoline base material (JP-A-7-188679). When it is desired to use DIPE as a combustibility improver for diesel fuel, the same treatment as described above may be performed using kerosene / light oil fraction instead of gasoline (Japanese Patent Application No. 6-85855).
issue). In the above two methods, the isopropyl alcohol separated from the water layer component by the distillation method or the like can be recycled to the reactor.

[0024]

EXAMPLES The present invention will now be described in more detail with reference to examples, but these are merely examples and do not limit the present invention.

Example 1 2000 g of zirconium oxychloride was dissolved in pure water,
While stirring, ammonia water was gradually added dropwise until the pH reached 10, to prepare zirconium hydroxide.
A catalyst was prepared by adding 7 l of a molar concentration of sulfuric acid at one time for immersion treatment, filtering, drying and calcining at 600 ° C. for 3 hours. The acid strength (Hammett function Ho) of this catalyst was measured with anthraquinone (discoloration point: Ho = -8.2), p-nitrotoluene (discoloration point in the ultraviolet region: Ho = -10.5) and p.
-Nitrochlorobenzene (color change point: Ho = -12.7)
All indicators showed an acidic color or the maximum absorption wavelength (ultraviolet region) on the acidic side as measured by using. Therefore, the acid strength of this catalyst is a Hammett function (Ho) with Ho ≤
It was -12.7.

10 g of the catalyst prepared above and 40 g of isopropyl alcohol were charged into a 200 cc autoclave equipped with a stirrer, reaction temperature was 200 ° C., reaction pressure was 5 kg / c.
The reaction was performed under the condition of m ² and the reaction recovered components 1 hour after the reaction was started were analyzed by gas chromatography (GC).
The conversion rate of isopropyl alcohol was 23.7 mol%, and the concentration of DIPE in the product produced by the reaction was 5
2.6 wt%, propylene concentration 26.7 wt%, other hydrocarbon concentration 0.0 wt%, and water concentration 20.
It was 7% by weight. Selectivity of converted isopropyl alcohol to DIPE (In calculating the selectivity, 1 mol of DIPE is obtained by the reaction of 2 mol of isopropyl alcohol.
Calculated as mol. In other words, this is
It is the selectivity based on the included carbon atoms. The same applies to the following examples. ) Was 61.9 mol%, and the selectivity to propylene was 38.1 mol%.

Example 2 20 g of the catalyst obtained by the same preparation method as in Example 1 and 40 g of isopropyl alcohol were charged into a 200 cc autoclave equipped with a stirrer, the reaction temperature was 200 ° C., the reaction pressure was 6 kg /
reacted in conditions of cm ^2, where the reaction recovering components of 1 hour after the start of the reaction was analyzed by GC, the conversion of isopropyl alcohol is 20.1mol%, DIPE concentration in the product produced by the reaction is 67. 1% by weight, propylene concentration is 14.7% by weight, and other hydrocarbon concentration is 0.1.
0% by weight, and the water concentration was 18.2% by weight. The selectivity from converted isopropyl alcohol to DIPE is 78.9 mol% and the selectivity to propylene is 21.1.
It was mol%.

Example 3 10 g of the catalyst obtained by the same preparation method as in Example 1 and 40 g of isopropyl alcohol were charged into a 200 cc autoclave equipped with a stirrer, the reaction temperature was 200 ° C., the reaction pressure was 6 kg /
The reaction recovered component was reacted under the condition of 3 cm ² for 3 hours after the reaction was started, and the reaction recovered component was analyzed by GC. As a result, the conversion rate of isopropyl alcohol was 22.3 mol%, and the DIPE concentration in the product produced by the reaction was 56. 2% by weight, propylene concentration is 22.4% by weight, and other hydrocarbon concentration is 1.
5% by weight, and the water concentration was 19.9% by weight. The selectivity of converted isopropyl alcohol to DIPE is 66.0 mol% and the selectivity to propylene is 31.9.
mol%, selectivity to other hydrocarbons is 2.1 mol%
Met.

Example 4 10 g of the catalyst obtained by the same preparation method as in Example 1 and 40 g of isopropyl alcohol were charged into a 200 cc autoclave equipped with a stirrer, the reaction temperature was 220 ° C., the reaction pressure was 7 kg /
The reaction was conducted under the condition of cm ² and the reaction recovery component after 1 hour from the reaction start was analyzed by GC. As a result, the conversion rate of isopropyl alcohol was 28.8 mol%, and the DIPE concentration in the product produced by the reaction was 62.2. % By weight, propylene concentration is 18.4% by weight, other hydrocarbon concentration is 0.4
% By weight, and the water concentration was 19.0% by weight. Selectivity from converted isopropyl alcohol to DIPE is 73.1 mol%, selectivity to propylene is 26.4 m.
The selectivity for ol% and other hydrocarbons was 0.5 mol%.

Example 5 10 g of the catalyst obtained by the same preparation method as in Example 1 and 40 g of a 90% isopropyl alcohol aqueous solution were stirred for 200 times with a stirrer.
It was put into a cc autoclave, reacted at a reaction temperature of 200 ° C. and a reaction pressure of 4 kg / cm ² , and 1 from the start of the reaction.
When the reaction-recovered component after time was analyzed by GC, the conversion of isopropyl alcohol was 20.7 mol%, the DIPE concentration in the product produced by the reaction was 19.6 wt%, the propylene concentration was 53.9 wt%, The other hydrocarbon concentration was 0.0% by weight, and the water concentration was 26.5% by weight. Converted isopropyl alcohol to DIPE
The selectivity to propylene was 23.0 mol% and the selectivity to propylene was 77.0 mol%.

Example 6 2000 g of zirconium oxychloride and 290 g of aluminum nitrate were dissolved in pure water, and ammonia water was gradually added dropwise with stirring to a pH of 10 to prepare a zirconium hydroxide / aluminum hydroxide composite metal hydroxide. Was prepared, and 7 l of 0.5 molar sulfuric acid was added at one time for immersion treatment, followed by filtration, drying, and calcination at 700 ° C. for 3 hours to prepare a catalyst. The surface area was 112 m ² / g. When the acid strength of this catalyst was measured using the same indicator as used in Example 1, all indicators showed a color on the acidic side or a maximum absorption wavelength (ultraviolet region). Therefore, the acid strength of this catalyst was Ho≤-12.7 in Hammett function (Ho).

10 g of the catalyst prepared above and 40 g of isopropyl alcohol were charged into a 200 cc autoclave equipped with a stirrer, the reaction temperature was 200 ° C., and the reaction pressure was 4 kg / c.
The reaction recovered component was reacted under the condition of m ² for 1 hour after the reaction was started, and the reaction recovered component was analyzed by GC. As a result, the conversion rate of isopropyl alcohol was 24.7 mol%, and the DIPE concentration in the product produced by the reaction was 68.4. % By weight, the propylene concentration was 13.2% by weight, the other hydrocarbon concentration was 0.5% by weight, and the water concentration was 17.9% by weight. Selectivity from converted isopropyl alcohol to DIPE is 8
0.4 mol%, selectivity to propylene 18.9mo
The selectivity to other hydrocarbons was 0.7%.

Comparative Example 1 10 g of γ-alumina and 40 g of isopropyl alcohol were charged into a 200 cc autoclave equipped with a stirrer, reacted at a reaction temperature of 200 ° C. and a reaction pressure of 3 kg / cm ² , and a reaction recovered component 1 hour after the reaction was started. Was analyzed by GC to find that the conversion of isopropyl alcohol was 13.5 m.
DIPE in the product produced by the reaction
The concentration was 37.2 wt%, the propylene concentration was 30.7 wt%, the other hydrocarbon concentration was 10.2 wt%, and the water concentration was 21.9 wt%. The selectivity from converted isopropyl alcohol to DIPE is 42.9 mol%,
The selectivity to propylene was 42.9 mol% and the selectivity to other hydrocarbons was 14.2 mol%.

[0034]

INDUSTRIAL APPLICABILITY According to the present invention, by using a solid super strong acid as a catalyst, a high conversion rate, a high selectivity and a simplified method can be efficiently used, and it is useful from isopropyl alcohol, particularly useful as a gasoline base material. DIPE can be produced, and this production method is suitable as an industrial production method of DIPE.

Claims (4)

[Claims] 1. A process for producing diisopropyl ether, which comprises etherifying isopropyl alcohol by a dehydration reaction in the presence of a solid superacid catalyst. 2. The solid superacid catalyst is selected from the group consisting of Group III of the periodic table.
2. The process according to claim 1, which is obtained by supporting a sulfate radical precursor on a hydroxide or oxide of a Group IV, Group IV or Group VIII metal and firing it. 3. The acid strength of the solid superacid catalyst is such that the Hammett function (Ho) is Ho <-11.9.
Production method as described. 4. The method according to claim 1, wherein the reaction raw material isopropyl alcohol has a purity of 80% or more.