DE2749065A1 - METHOD FOR PRODUCING AN AMINE - Google Patents

Description

SHELL INTERNATIONAL RESEARCH MAATSCHAPPIJ B.V. The Hague, Netherlands

"Process for the preparation of an amine"

claimed priority:

k. November 1976 - V.St.A. - No. 738 491

The invention relates to a method for producing an amine by reacting an alcohol, aldehyde or ketone with up to 25 carbon atoms with ammonia, a primary or secondary Amine in a reducing atmosphere in the presence of a catalyst.

Many catalysts have been described for the production of amines from alcohols, e.g. in GB-PS 36 ΊΐΊ typical hydrogenation catalysts for the production of amines

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from alcohols. In US-PS 3,128,311 alcohols are with Ammonia in the presence of a catalyst containing nickel, copper and an oxide of chromium, titanium, thorium, zinc or magnesium, implemented. U.S. Patent No. 3,520,933 discloses a number of metals used in combination with one made by pyrolysis Acid or a polyacid are suitable for the conversion of alcohols to amines.

However, there is no indication in the literature that the

/ Molybdenum and / or tungsten

specific combination of copper and / a synergistic effect on higher selectivity and catalyst stability Has.

The invention therefore relates to a method for producing an amine by reacting with an alcohol, aldehyde or ketone up to 25 carbon atoms with ammonia, a primary or secondary amine with 1 to 8 carbon atoms in a reducing Atmosphere which is characterized in that the reaction is carried out in the presence of a catalyst which 0.005 to 50 percent by weight of copper and / or copper oxide and 0.005 to 45 percent by weight of a molybdenum and / or tungsten oxide, each determined as a metal component and based on contains the total catalyst.

The catalyst used in the process according to the invention is located generally on a suitable carrier. The amount of copper, either as metal or copper oxide or theirs Mixture, calculated as percent by weight of metal from the total catalyst

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sator, is preferably 0.05 to 40 percent by weight, in particular 0.1 to 30 percent by weight. The amount of molybdenum oxide, tungsten oxide, or their mixture, also calculated as Percent by weight of metal from the total catalyst is preferably 0.1 to 35 percent by weight, in particular 0.15 to 30 percent by weight. Preferred molybdenum or tungsten oxides are the trioxides.

Conventional porous and heat-resistant materials are used as the support material for the catalyst used in the process according to the invention Carriers, which are opposite both to the starting material and to those in the process according to the invention formed products are resistant. The carriers can be of natural origin or synthetic. Very suitable

ι-

are substances containing silica and / or aluminum oxide,

/ Charcoal e,. e.g. aluminum oxide / pumice stone, magnesium oxide,

Zirconium oxide, diatomaceous earth, puller earth, silicon carbide, porous agglomerates of ^ silica and / or silicon carbide, Clays, artificial and natural zeolites and ceramic products, particularly suitable are heat-resistant products that contain silica and / or aluminum oxide, especially if-alumina-containing materials.

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The catalyst used in the process according to the invention can can be produced in various ways, e.g. by precipitating the metal components together on a carrier in Powder form or in globules or by coprecipitation with the carrier from aqueous solution. Preferably the However, the catalyst is prepared by treating the support material with an aqueous solution of suitable salts impregnated active metals, then dried and calcined the impregnated carrier at temperatures of 100 to 600 ° C. as The preferred solvent is water, but some organic solvents can be used.

Suitable salts for aqueous systems are chlorides, bromides, nitrates, acetates and lactates. Ammonium salts are very suitable.

On the other hand, you can also

Solutions of salts of the active substances and the carrier

spray drying and calcining at temperatures of 100 to 600 ⁰ C.

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Before use, the catalyst used in the process according to the invention is activated by heating in a reducing atmosphere, for example in hydrogen or ammonia. Preferred iet hydrogen. A suitable temperature for this activation is between 250 and 600 ° C. The time it takes to do this depends on the temperature, i.e. the higher the temperature, the shorter the time. Appropriately, this activation takes 6 minutes to 2Ί hours, although times outside these limits are also suitable

• ■ -

are. For economic reasons, however, one will be within the specified limits remain.

As starting material for the process according to the invention are aliphatic, cycloaliphatic, arylaliphatic or aromatic alcohols, ketones or aldehydes with up to 25 », preferably up to 20 carbon atoms, preferred. These compounds can also be unsaturated, e.g. with 1 or 2 olefinic double bonds, and carry substituents which are inert under the given reaction conditions, e.g. alkyl radicals with 1 to <t carbon atoms which are bonded via Xther bridges. Aliphatic or cycloaliphatic are of particular economic importance Alcohols / aldehydes with up to 20 carbon atoms, e.g. Kthanol / al, Propanol / al, isopropanol, butanol / al, isobutanol / al, 2-Xthylhexanol / al, decanol / al, dodecanol / al, hexadccanol / al, cyclopentane !,

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Cyclphexanol, cyclooctanol, cyclododecanol, benzyl alcohol / aldehyde, phenylethyl alcohol / aldehyde, .1 , butanediol / al, 1,6-hexanediol / al, 1,5-pentadiol / al and 1,8-0ctanediol / al.

Examples of suitable ketones are acetone, methyl ethyl ketone, Methyl isobutyl ketone, phenyl methyl ketone, phenyl ethyl ketone, 3 ~ Decanone, 5-dodecanone, cyclopentanone, cyclohexanone, cyclooctanone and cyclododecanone.

Primary or secondary amines, for example alkylamines, cycloalkylamines or arylalkylamines with 1 to 8 carbon atoms, in particular alkylamines having from 1 to I ¹ carbon atoms and 1 amino group in the molecule as the amine for the process of this invention preferred. Specific examples of suitable amines are monomethylamine, dimethylamine, methylethylamine, monoethylamine and diethylamine. Monomethylamine and dimethylamine are preferred.

In the process according to the invention, the alcohols, aldehydes or ketones are expediently used with at least one equivalent Ammonia or amine reacted, whereby the ammonia or the amine can also be used in excess, e.g. up to 50, preferably up to 20 mol of ammonia or amine per hydroxyl or carbony group to be converted.

The reaction is conveniently carried out at a temperature of 160 to 350 ° C., preferably from 180 to 300 ° C., and a reaction

2 2

pressure from 1 to 300 kg / cm, preferably IO to 75 kg / cm, through-

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guided-. The reaction is preferably carried out in the presence of Hydrogen through, expediently with hydrogen partial

2 , 2

pressures from 0.7 to 220 kg / cm, preferably 7 to 75 kg / cm. It is beneficial to have a molar ratio of hydrogen to alcohol, Aldehyde or ketone above 1 to use. The reaction system can also partially with inert gases, such as nitrogen or argon, be applied.

The process according to the invention can be continuous or discontinuous be performed. In the case of a discontinuous e.g.

Working method is / a high pressure autoclave equipped with a stirrer is charged with the alcohol, aldehyde or ketone, the amine or ammonia and the catalyst, charged with hydrogen and heated to the reaction temperature. After the mixture the has reacted for the desired time, the autoclave is cooled down

M. -

excess hydrogen is drained, the products are in worked up conventionally.

e.g.

In a continuous mode of operation, / becomes a vertical high pressure column charged with the catalyst, alcohol and amine at the top of the column. At the same time, hydrogen is in the Feeded cocurrent or countercurrent to the column. Of the

In the cycle, hydrogen is advantageously fed back into the process /. Appropriate temperature and pressure conditions are maintained during the reaction. The product will be at the bottom taken from the column, freed from hydrogen and worked up in a conventional manner.

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• Another continuous way of working is that you allows the reaction mixture / in which the catalyst is dispersed to trickle over packing or damming bodies in a tower.

The examples illustrate the invention.

Example 1 a) Copper / tungsten catalyst

A solution of 9.6 g of copper nitrate in 15 ml of deionized water is mixed with a solution of 3 g of ammonium metatungstate in water. Without delay, this solution is added with good stirring to 48 g of alumina having a surface area of about 260 m / g _U nd a pore volume of about 0.26 cm / g (18x30 mesh Reynolds RA-1). The catalyst is gently stirred for 15 minutes and dried with a stream of warm air. The catalyst is then poured into a heat-resistant glass tube and dried in a stream of air at a rate of 500 ml / minute in 50 ° increments at a temperature of 25 to 500 ° C. The treatment time is 30 minutes at 100 ° C, then 15 minutes at each 50 level. The resulting cooled and calcined catalyst is then reduced with hydrogen diluted with nitrogen, the temperature gradually rising to 500.degree.

b) copper / molybdenum catalyst

9.6 g of copper nitrate are mixed with 40 ml of an aqueous ammonium hydroxide solution (28 to 30% ammonia) heated. In this solution

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2 g of ammonium molybdate are dissolved. About half of the resulting solution is used to impregnate 48 g of aluminum oxide (28x30 mesh Reynolds RA-1). The impregnated carrier is dried in 50 ° steps in air from 100 to 300 ° C., cooled and impregnated with the rest of the solution. The drying is repeated, but this time to 500 ^C C. The catalyst is then reduced in hydrogen at a temperature up to 500 ⁰ C.

Example 2

1. For comparison, a catalyst not according to the invention is prepared by impregnating an aluminum oxide support with a 50 percent strength by weight aqueous copper nitrate solution and reducing the impregnated support in hydrogen at 500.degree. The catalyst contains 10 percent by weight copper. 10 cm of this catalyst are introduced into a reactor with a trickle phase and a volume of about 25 cm. Monomethylamine and 1-dodecanol are fed into the reactor at a liquid hourly space velocity of 1.1 and a molar ratio of amine to alcohol of 3: 1. The reactor is kept at a temperature of 200 ° C. Hydrogen is fed into the reactor at a rate of 100 cm / minute. The pressure is kept at 27 kg / cm. After a reaction time of 5 hours, the dodecanol conversion is 92.7 mol percent, the selectivity to methyldodecylamine is 85.9 mol percent and the selectivity to C ₃₄ and C ₃₅ amines is 14.1 mol percent.

The experiment is repeated. After a reaction time of 3 hours

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the alcohol conversion is 86.8 mole percent, the selectivity to methyldodecylamine is 72.1 mole percent and the selectivity to C ₂₄ and C ₂₅ amines is 21.3 mole percent. The stability of the catalyst is poor.

2. There are 10 cm of a copper-on-aluminum oxide catalyst manufactured and tested according to 1. The catalyst contains 3.9 percent by weight copper. The reactor is in this case with Dimethylamine and 1-dodecanol in a molar ratio of 3: 1 loaded. The liquid hourly space velocity is 1.1 and the reactor temperature is maintained at about 220.degree. hydrogen is fed into the reactor at a speed of 100 cm /

Fed in for 2 minutes. The pressure is kept at 27 kg / cm. After a test duration of 2 hours, the dodecanol conversion is 80.6 mol percent, the selectivity to dimethyldodecylamine 72.2 mol percent, the selectivity to methyldodecylamine 20.4 mol percent and the selectivity to C_r ~ amines 7.4 mol percent. After a reaction time of 3 hours, the alcohol conversion is 81.7 mol percent, the selectivity to dimethyldodecylamine 69.7 mol percent, the selectivity to methyldodecylamine 20.1 mol percent and the selectivity to C ₂ c ~ amines 10.2 mol percent.

3. According to the procedure of Example 1a, but with the difference that no copper is used, a tungsten catalyst on aluminum oxide with a tungsten content of 4.6 percent by weight is produced. A reactor with a trickle phase is charged with 10 cm of this catalyst, dimethylamine and 1-dodecanol at an hourly liquid space velocity

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of 1.1 and a molar ratio of 3: 1 are fed into the reactor. The reactor temperature is about 225 ° C, the pressure about 27 kg / cm. Hydrogen is fed into the reactor at a rate of 100 cm / minute. After a reaction time of 4 hours, the conversion is only 3 mol percent.

4. The service life of a copper / tungsten catalyst according to the invention for alumina is examined. The catalyst is prepared according to Example 1a and contains 3.3 percent by weight Copper and 3.9 weight percent tungsten. A reactor with trickle phase is charged with 25 cm of this catalyst, Monomethylamine and an alcohol mixture, which consists of alcohols with 14 and 15 carbon atoms, are at a molar Amine to alcohol ratio of 3: 1 and a liquid hourly space velocity of 1. The hydrogen is fed into the reactor at a rate of 750 cm / minute. The pressure is kept at 29 kg / cm. the Results are summarized in Table I.

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Table I.

Service life of a copper / tungsten catalyst, test duration, temperature, alcohol selectivity, mol percent

hours ⁰ C UIUWdIlUXUIi ¹ J
Mole percent I.
Mono
me thy 1-
amine
derivative Dirnethyl
amine
Derivative higher
Amines 2 199 93.7 87.8 2.7 9.4 3.6 208 93.1 82.1 3.1 14.9 19.6 208 91, 0 75.2 5.2 19.6 27.9 208 87.4 79.4 4.1 16.5 44.3 208 79.3 82.2 3.2 14.6

5. The service life of a copper / tungsten catalyst according to the invention on aluminum oxide prepared according to the procedure of Example 1a and 3.6 percent by weight copper and contains 3.9 weight percent tungsten is examined. A reactor with a trickle phase is 10 cm of this catalyst charged, dimethylamine and 1-dodecanol are at one hourly liquid space velocity of 1 and a molar ratio of amine to alcohol of 3: 1. Of the Hydrogen enters the reactor at a rate of

3 2

100 cm / minute fed. The pressure is kept at 29 kg / cm. The results are summarized in Table II.

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Table II Life of a Copper / Tungsten Catalyst

Test temperature, alcohol selectivity, mole percent duration, _ conversion-

hours ⁰ C lung,
Mole percent Dimethy1-
dodecyl
amine Methy1-
dodecyl
amine C ₂₄ - and
C ₂₅ amines 2.2 203 95.7 76.2 7.9 15.9 3.7 198 87.4 84.3 8.2 7.5 20.1 203 95.0 82.5 6.4 11.1 28, a 203 94.7 79.7 7.9 12.4 44.5 203 94.5 80.7 6.4 12.9 68.3 203 95.8 80.2 6.9 12.9 94.4 193 92.5 80.9 7.8 11.2 126.0 195 96.3 80.8 6.6 12.6

6. Following the procedure of Example 1a, a Copper / tungsten catalyst on alumina containing 3.3 percent by weight copper and 3.9 percent by weight tungsten, manufactured. A reactor with trickle phase is charged with 10 cm of this catalyst, dimethylamine and n-butanol are in the Reactor with a liquid hourly space velocity of about 1 and an amine to alcohol molar ratio of 3: 1 fed in. The hydrogen is released at a rate of 100 cm / minute and a constant pressure of 27 kg / cm fed in. The reactor temperature is about 214 ° C. After a test duration of 4 hours, the alcohol conversion is 89.3 Mole percent, the selectivity to dimethylbutylamine 80.9 mole percent, the selectivity to methylbutylamine 10.8 mole percent and the

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Selectivity to C _g and C amines 8.3 mol percent.

7. According to the procedure of Example 1a, a copper / Tungsten catalyst made on alumina, which is 5.1 percent by weight Contains copper and 4.2 percent by weight tungsten. A reactor with trickle phase is 10 cm of this catalyst charged, dimethylamine and lauraldehyde are fed into the reactor at a liquid hourly space velocity of about and an amine to aldehyde molar ratio of about 3: 1. The hydrogen is fed into the reactor with a Fed in at a speed of 100 cm / minute. The pressure is kept at 27 kg / cm. The reactor temperature is 183 ° C. After a test duration of 1 hour, an aldehyde conversion of 95.8 mol percent and a selectivity to dimethyldodecylamine of 80.7 mole percent, a selectivity to C -.- and C ^ -amines of 19.3 mole percent and a trace of methyldodecylamine.

After a test duration of 2 hours 45 minutes, the aldehyde conversion is 85.3 mol percent, the selectivity to dimethyldodecylamine 76.8 mol percent, and the selectivity to C ₃₄ and C ₃₅ amines 23.2 mol percent. A trace of methyldodecylamine is also present.

8. According to the procedure of Example 1b, a copper / molybdenum catalyst on aluminum oxide is prepared which contains 4.7 percent by weight copper and 2.0 percent by weight molybdenum. A reactor with a trickle phase is charged with 10 cm of this catalyst , dimethylamine and 1-dodecanol are added to the reactor

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a liquid hourly space velocity of about 1 and a molar ratio of Amiη to alcohol of 3: 1. The hydrogen is fed into the reactor at a speed

3 2

speed of 100 cm / minute. The pressure is set to 27 kg / cm,

the temperature kept at 225 ° C. After a test duration of 1 hour, the alcohol conversion is 93.3 mol percent, the selectivity to dimethyldodecylamine 82.6 mol percent, the selectivity to methyldodecylamine 8.2 mol percent and the selectivity to C _{1 - and C 25} amines 9.2 mol percent.

After a test duration of 3 hours, an alcohol conversion of 73.5 mol percent, a selectivity to dimethyldodecylamine of 87.8 mol percent, a selectivity to methyldodecylamine of 6.1 mol percent and a selectivity to C ₃₄ and 6.1 mol percent are obtained.

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Claims (8)

Claims l _v Process for the preparation of an amine by reacting an alcohol, aldehyde or ketone with up to 25 carbon atoms with ammonia, a primary or secondary amine with 1 to 8 carbon atoms in a reducing atmosphere, characterized in that the reaction is carried out in the presence of a catalyst which contains 0.005 to 50 percent by weight of copper and / or copper oxide and 0.005 to 45 percent by weight of a molybdenum and / or tungsten oxide, each determined as a metal component and based on the total catalyst, 2. The method according to claim 1, characterized in that a catalyst is used which is 0.05 to 40 percent by weight Contains copper and 0.1 to 35 percent by weight of molybdenum and / or tungsten oxide. 3. The method according to claim 1 and 2, characterized in that a catalyst on an alumina support, preferably Jf-alumina was used. 4. The method according to claim 1 to 3 » characterized in that hydrogen is used as the reducing atmosphere. 5. The method according to claim 1 to 4, characterized in that 80 ^ 820/0728 2
the reaction is carried out at a pressure of 1 to 300 kg / cm. 6. The method according to claim 1 to 5 »characterized in that the reaction is carried out at a temperature of from about 160 to about 350.degree performs. 7. The method according to claim 1 to 6, characterized in that the amine used is monomethylamine or dimethylamine. 8. The method according to claim 1 to 7, characterized in that a molar ratio of amine to alcohol of 1: 1 to 50: 1 is used. 809820 / 072S