DE1160426B - Process for the preparation of alcohols by hydrolysis of aluminum alkoxides - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Boarding school Class: C 07 c

German class: 12 ο -5/02

Number: 1160 426

File number: C 25440IV b / 12 ο

Filing date: November 4, 1961

Opened on: January 2, 1964

The invention relates to the hydrolysis of aluminum alkoxides. In one way it concerns a process according to which aluminum alkoxides are hydrolyzed in countercurrent in several stages will.

The hydrolysis of aluminum alkoxides presents a number of problems in that it is difficult to obtain one To achieve complete conversion of the alkoxides into alcohols, and also often difficulties in the Separation of the products of hydrolysis occur. It was z. B. found that mixing must be provided during hydrolysis in order for the reaction to proceed efficiently; is the However, if the reaction is too violent, an emulsion of the alcohols formed is formed in the product of the hydrolysis. Various methods of carrying out the hydrolysis have been proposed; so became the Hydrolysis carried out e.g. in nozzles, in centrifugal pumps, outflow mixers and similar devices.

The method according to the invention is carried out by the aluminum alkoxides with a hydrolyzing agent under conditions that require vigorous mixing and countercurrent occurs in a series of contact zones that are vertical with respect to one another are arranged. The alcoholic product is accumulated at one end of the series of zones, and the product of aluminum hydrolysis collects at the opposite end of the row of zones.

The alkoxides used in the practice of the invention contain aluminum alkoxy compounds, in which the alkoxy groups contain 1 to 30 carbon atoms or more. While single Alkoxides can be used, alkoxides are usually mixtures of compounds, in which various alkoxy groups are present. The alkoxides can in a known manner be obtained by oxidation of an aluminum trialkyl addition product. This addition product is produced by oxidation with oxygen (air) in a known manner, usually at temperatures converted to alkoxides between about 20 and 50 ° C and pressures between about 1.4 and 4.2 atmospheres, wherein the alkyl groups are converted to alkoxides. Those formed according to this procedure Alkoxides have a composition with Poisson's distribution of the alkyl groups. A distinctive one Composition of the alcoholic prepared according to the process described above Product is the following:

Process for the production of alcohols
by hydrolysis of aluminum alkoxides

Applicant:

Continental Oil Company, Ponca
(V St A) V ^^ £? ^}

ity, OkIa.

Named as inventor:

Charles O. P. Albert, Bellaire, Tex. (V. St. A.)

Claimed priority:

V. St. v. America 7 November 1960

(No. 67 633)

Weight percent

C ₂ OH 1.80

C ₄ OH 8.12

C ₈ OH 17.85

C ₈ OH 22.75

C ₁₀ OH 20.64

C ₁₂ OH 14.58

C ₁₄ OH 8.39

C ₁₆ OH 4.11

C ₁₈ OH 1.76

All or any proportion of the alkoxides formed can be obtained by means of the process are hydrolyzed according to the invention.

Specific examples of individual alkoxides that can be used include named: aluminum ethoxide, aluminum isopropoxide, aluminum butoxide, aluminum hexoxide, aluminum decoxide, Aluminum tetradecoxide, aluminum octadecoxide and aluminum eicosoxide.

The aluminum alkoxides are hydrolyzed by using a common hydrolyzing agent brought into contact, e.g. a mineral acid, ζ. Β. Sulfuric or hydrochloric acid, water, steam, or different bases, such as. B. sodium hydroxide, potassium hydroxide and the like. Alcohols and aluminum salts or aluminum hydroxide form the reaction product of the hydrolysis, depending on the particular case chosen hydrolyzing agent. As such, an acid is usually preferred which forms an aluminum salt, since the salt is easier to separate from the alcohols than aluminum hydroxide.

309 777/396

The hydrolysis is carried out within a temperature range that is determined by the individual hydrolyzing Agent and the hydrolyzed alkoxides and is, for example, between about 25 and 150 ° C. As a rule, the hydrolysis is carried out at atmospheric pressure, but higher pressures can also be used Application. The agent used for hydrolysis is at least in a stoichiometric amount used and usually in such a medium, caused by the propellers 6 Movement to be dispersed. The arrangement of the propellers between the floors 4 of the hydrolysis column causes intimate contact of the reactants in each of the areas between the Floors. A settling and separation zone is provided at each end of the hydrolysis column in which the separation of the products of the hydrolysis takes place. The collected in the upper separation zone 11

sufficient to produce an excess of alcohol over the stoichiometric io melting product from this

to deliver, namely, based on the alkoxides, of about 2 to 200%. The preferred amount of hydrolyzing agent is different when used an acid such as sulfuric acid, for example, an excess of about 2 to 20% over the stoichiometric amount used addition. When using a base such as sodium hydroxide, such an amount of hydrolyzing agent is used that an excess is over the stoichiometric amount is from 10 to about 50%. With water, on the other hand, there is an excess over the stoichiometric amount used is between about 50 and 200%. The reaction takes place at reaction times between about 2 and 30 minutes.

The hydrolysis is advantageously carried out with the aqueous phase forming the dispersant, the alkoxides being dispersed therein by vigorous agitation such as stirring. It can one of the common methods and apparatus for grounding line 10 is derived. This product, which is in the Usually a crude mixture of alcohols containing some aluminum salts and hydrolyzing agent contains can further treated with a neutralizing agent, then washed and later fractionated to separate the various alcohols in the product.

The aluminum salt solution collects in the lower separation and settling zone 13 and is through the line 12 withdrawn therefrom.

As indicated above, the hydrolysis is exothermic and the reaction temperature is controlled by introducing a cooling liquid into the cooling jacket 18. The cooling liquid is supplied through the line 20 and removed through the line 20. Any liquid customary for heat exchange, for example water, can be used for this purpose.
In place of the described device for off

The hydrolysis can be carried out using an inclined or horizontal device, eg stirrer, rotating disks, atomizer device instead of the preferred lowering nozzles, and the like
be strong enough to disperse the alcohols,

but not so strong that an emulsion is formed in the aqueous phase.

The hydrolysis is an exothermic reaction and means for removing the heat are in the process provided to easily control the temperature of the hydrolysis. It can be any usual right can be used. When using a horizontal device, the deposition of the Phases are carried out after each stage.

example 1

18.14 kg of aluminum triethyl, diluted with 18.14 kg of inert paraffin, were in a high pressure vessel

Heat exchange system can be used for this purpose at 40 at 105.5 atü and 105 to 120 ^c C with ethylene in; z. B. a simple cooling jacket can be brought to the touch. The reaction was stopped and the reaction zone was used. as one for obtaining maximum yield

The invention is described below using the C ₁₀ -C ₁₂ aluminum alkyls in a sufficient amount

Drawing described in more detail. "'"

The drawing is a schematic representation of a cross section of an induction device the intimate touch that b

tion of a preferred embodiment of the invention is used.

Ethylene had reacted with the aluminum triethyl. The addition product became the reaction vessel removed and oxidized with air at 20 to 30 ° C. The resulting aluminum alkoxides were then vacuum stripped or cleaned to remove the solvent and unwanted during the

The column 2 used for hydrolysis consists of 50 oxidation to remove by-products formed.

an elongated vertical vessel with a series of vertically spaced horizontal ones Baffles 4, which are open in the middle, and a series of extending through the openings, vertically spaced propellers 6 from one with a Motor 7 connected shaft are driven. The hydrolysis column is perpendicular to one another surrounding cooling jacket 18 extending.

A hydrolyzing agent, in this case aqueous sulfuric acid, is placed over the top tray introduced through line 14 into the hydrolyzing column. Aluminum alkoxides are in the lower Part of the column between the second and third tray, counting from the bottom, introduced. That hydrolyzing agent and the alkoxides pass through the hydrolyzing column in countercurrent, the Alkoxides in the aqueous phase, the dispersion-Then the aluminum alkoxides were in countercurrent in a multi-stage hydrolysis reactor of 76.2 mm diameter containing 14 zones Brought into contact with sulfuric acid. The aluminum alkoxides were in the thirteenth zone, dated The upper part of the reaction vessel is inserted into this. An aqueous solution of sulfuric acid was above the uppermost zone in an amount of 1.52 moles of sulfuric acid per mole of alkoxide in the Reactor introduced. In each stage, turbine-type stirrers were set at a speed of 1300 rpm used to achieve intimate contact between reactants. The reaction temperature was along the length of the reaction vessel different and was between 58 and 94 ° C. The pressure in the reaction vessel was the air pressure. the The residence time in the reaction zones was 14.1 minutes when calculated from the inflow volume.

Claims (1)

5 6 the reactant and the volume of the actuator introduced, in an amount of away from reaction zones. 1.53 MoJ sulfuric acid per mole of alkoxide. The alum From the lower settling zone was continuous and the alcohol was continuously down on an alum solution containing 8.03% Al ₂ O ₃ drawn off the reactor and placed in an outer container pulled. Allow the 5 accumulated in the upper settling zone to settle. Alcohols were also drawn off continuously and, as in Example 2, turbine-type stirrers with a dilute sodium hydroxide solution were used again at a speed of 1400 rpm, and neutralized. The neutralized alcohols were then the pressure was that of the air. The temperature washed twice with water and distilled. along the reactor was 50 to 84 ° C. It was found that the alcohols of the pro-io time in the reaction zones was 14.2 minutes, product in the molecular weight range from C ₂ to C ₁₈ Under these conditions of operation in the same way Composition had: current was found to be achieving a W'cht or ze t complete hydrolysis of the aluminum alkoxides impossible was. 0.35 _l5 ^ _us above examples it is apparent that in an ₄ 2.32 essentially complete hydrolysis of the alkoxides C ₆ OH 6.83 when using the method according to the invention, C ₈ OH 14.99 ie operation in countercurrent, can be achieved in C ₁₀ OH 18.78 in contrast to incomplete hydrolysis during operation C ₁₂ OH 18.86 3 ° in cocurrent. 18 50 ^ ' ^e cited data show that even with 11 55 a high degree of dispersion is difficult to achieve a strong one On 782 conversion of aluminum alkoxides can be achieved quickly ¹⁸ 'bar. The reason for this is obviously that Example 2 ²⁵ ^ ^As P ^rocm kt the hydrolysis tends to affect the Outside of not yet reacted Aluminum alkoxides, which form in a manner similar to alkoxide particles and thereby form another Prepared according to Example 1, were to prevent hydrolysis. The procedure according to the a multi-stage hydro-invention containing nine zones offers the advantage of immediate loading Lysing reactor of 76.2 mm diameter for stirring 30 partially hydrolyzed particles with high action brought. The aluminum alkoxides were in concentrations of hydrolyzing agents and the eighth zone, calculated from above, in the reac- delivers complete hydrolysis of the introduction space. An aqueous solution of alkoxides.
Sulfuric acid was in one over the top zone Amount of 1.57MoI sulfuric acid per mole of alkoxide 35 claims:
introduced into the reaction vessel. Turbine-like Stirrers with a speed of 1400 rpm became 1. Process for the production of alcohols used in each stage to ensure intimate contact by hydrolysis of aluminum alkoxides, to achieve between the respondents. Which indicates that the hydro-reaction temperature was along the reaction space 40 lysis in countercurrent in a number of changes and was between 50 and 84 ° C. The settlement zones under mixing and pressure the air pressure was in the reaction vessel. The separation of the phases is carried out, whereby The residence time in the reaction zones was the alcohols as one phase and the AIu-13.6 Minutes. Build up minium hydroxide as the second phase. Under the conditions given above, 45 2. Method according to claim 1, characterized in that a completely hydrolyzed alcohol stream indicates that the reaction zones lower broken off at the top of the column are arranged right in relation to each other, and processed as in example 1. 3. The method according to claim 1 and 2, there- . . characterized in that the hydrolyzing Example 3 _5o agent is sulfuric acid. The aluminum alkoxides used in Example 2 4. Process according to Claims 1 to 3, characterized were characterized in cocurrent with sulfuric acid in that the hydrolysis at a same multistage hydrolysis reactor with a temperature between 25 and 150 ° C takes place. 9 zones and 76.2 mm diameter for reaction brought. The aluminum alkoxides and the aqueous 55 publications considered: Sulfuric acid solution were both described above in the Re-Annalen der Chemie, 629 E, p. 247. 1 sheet of drawings 309 777/396 12.63 © Bundesdruckerei Berlin