DE3217429A1 - Process for the preparation of alcohols by the catalytic hydrogenation of esters of organic acids - Google Patents

Description

* DR. GERHARD RATZEL ^: ·. ^:: ·. ^: " ^: ·· ^: - ^ oVmanVhε.μ ι, 7.r.ai 19«?

PATENT Attorney JJ Seckenhelmer Strasse 36 a · Τ? ' (0621) 406315

Poatachack: Frankfurt / M. No. 8293-603

Bank: Deutioht Bank Mannhalm (BLZ 67070010) No. 72OCOOO

Talaer.-Coda: Oarpal Telex 463670 Par. D

Institut Prancais du Petrole ή-, Avenue de Bois-Preau
92502 Rueil-Malmaison
France

Process for the production of alcohols by the catalytic hydrogenation of Organic acid esters

ZI / k L Ό

The production of higher alcohols or fatty alcohols today is essentially based on synthetic methods Secured away from olefins, in particular through the OXO and Ziegler processes. Avenge in adoration of the tensions surrounding the procurement of hydrocarbons, it is desirable to to turn to sources other than raw materials that are as recyclable as possible should * The fatty alcohols, whose areas of use are very different, fit into this new production scheme by converting fatty acid esters, extracts from vegetable or animal origin Oils into the corresponding fatty alcohols.

The production of fatty alcohols from fatty acid esters can be effected by reduction by chemical means, such as the double hydride of lithium and aluminum (compare Finholt et all., J. Am. Chem. Soc, Volume 69, page 1199, (19 * 7)), Diborane (BoHg) or sodium (compare French Patent No. 388,895 and USA Patent 863,352). Another type of reduction process is used catalytically activated hydrogen.

The catalysts known for this reaction essentially consist of the mixed oxides of copper and chromium, which may be deposited on a support: GDR Patent No. 122 067, DBP No. 2,613,226 and 2,800,384, USA Patent No. A 072 726, Belgian patent No. 864 567 and French patent No. 1 420 720 and 1 572 167. By seeding with the oxides of alkali metals (Na ₂ O, K _g O) or alkaline earth metals (MgO, Ca O , Ba O) one can choose the selectivity and

improve the stability of the catalysts: GDR Patent No. 71 544-, DBP No. 2 511 377 and 2,613,226 U.S. Patent Nos. 1,512,414 and 2,285,448, British Patent 1,151,939 and French Patent Nos. 1,426,720 and 1,572,167. Catalysts based on transition metals are also the subject of patents: DBP No. 2800 384 and french patent 2 021 633

The number of patents relating to the direct hydrogenation of esters in the presence of supported catalysts metal-based is relatively limited. In contrast, the hydrogenation is the corresponding Acids (the subject of a much larger number of works that have led to patents: GDR patent No. 2133 768, U.S. Patent No. 2 6o7 8o5, 2 6o7 8o7 and 4 o14 478, French Patent No. 1 293 723 and 2 34o 922. This is explained by the greater reactivity of organic acids in comparison to the corresponding methyl or ethyl esters, as HS Broadbent et al. in Annals of New York Academy of Science 172, 194 (197o) have shown. However, special materials are required for the direct hydrogenation of acids, which the corrosive effect of these acids during the various stages of the feed, the reaction and possibly withstand the circuit during the operation of the device, whereby the investment costs increase considerably. In contrast, the methyl or ethyl esters of fatty acids are very little aggressive compounds.

Furthermore, the following disadvantages, which are related to the type of catalytic converter, must be taken into account:

- for catalysts based on mixed oxides of copper and chromium (if necessary inoculated) one must under high pressure (in practice

all cases higher than 2 atmospheres) and a temperature of 250 to 35O ⁰ C because these catalysts are only slightly effective under less stringent temperature and pressure conditions.

- with catalysts based on transition metals, which are deposited on a support, we must at a less high temperature work (25O ⁰ C, preferably below 200 ⁰ C), in order to keep the reduction of the formed alcohol to a hydrocarbon in limits; as a result, reaction pressures of more than 100 bar are required in order to obtain good selectivities with an acceptable degree of conversion.

The thermodynamic analysis of the conversion of esters to alcohols shows, however, that the reaction is possible at low pressure, provided that that a sufficiently active and selective catalyst is used.

It has now surprisingly been found that it is possible to hydrogenate an ester an alcohol according to the following scheme:

R ^ ₁ -C + 2 Ho -> R "CH ₀ OH + R ₀ OH

¹ ^ O - R _p ^{2 1 2 2} where R ,. = Alkyl with 2o carbon atoms and R ₀ = alkyl with 1-4 carbon atoms, preferably 1 or 2Ko in a continuous or discontinuous I sto reactor under a total pressure of 10 to 100 bar, * - preferably 30 to 80 bar (but you can without too

Disadvantage e.g. go up to 300 bar) and a temperature of 150 to 300 ° C, preferably 180 to 250 ° C., with a hydrogen / ester molar ratio of 2 to 10, preferably 2 to 5. This reaction can be realized under the conditions mentioned above if a supported catalyst is used used, which contains the following elements: Rhenium in an amount of 0.5 to 5 wt. #, preferably 0.5 to 3 wt .- #, and at least a metal from group VIII, preferably a noble metal from group VIII, in particular from the group Iridium, palladium, platinum, rhodium and ruthenium in an amount of 0.01 to 3 wt .- #, in particular 0.1 to 1 wt%; the carrier can be selected from the group Silicon dioxide, the various types of aluminum oxide, silicon dioxide-aluminum oxide, Coal, and preferably from the group of the various types of aluminum oxide.

The catalyst can be prepared by various methods of carrier impregnation and the invention is not limited to any particular method. The impregnation consists e.g. in that the preformed support with an aqueous solution of a compound of the chosen Brings noble metal into contact, the volume of the solution being an excess in relation to the Retention volume of the carrier is or equal to this volume. After getting the vehicle and the solution left in contact with each other for several hours, the impregnated carrier is filtered off,

washed with distilled water and then ge. dries. Then you impregnate with the Preimpregnated and dried precious metal compound

Carrier with a soluble compound of rhenium Another procedure is that the preformed support with a common aqueous solution of a noble metal compound and a rhenium compound, the Volume of the solution is equal to or greater than the retention volume of the carrier.

Another method is that the moist carrier powder with the precursors of the Catalyst mixed and then brings it into shape and dries. (Precursor = »preliminary stage)

Examples of metallic precursors useful in making the catalyst are the following:

As noble metal one can use compounds like the chlorides, nitrates or soluble salts of organic Use acids that are in the impregnation solvent are soluble, e.g. palladium, rhodium or ruthenium chloride, hexachloroplatinic acid or Hexachloroiridic acid, palladium or rhodium nitrate, soluble salts of organic acids, such as palladium acetate, but also palladium tetrammine chloride or nitrate, platinum tetrammine, rhodium hexammine, Ruthenium hexammine. You can also use organometallic compounds of noble metals, which are dissolved in a hydrocarbon, e.g. in a saturated paraffinic hydrocarbon, whose hydrocarbon chain contains 6 to 12 carbon atoms (hexane, heptane, octane, Nonane, decane, undecane, dodecane), or in a naphthenic hydrocarbon with 6 to 12 Carbon atoms (cyclohexane, methylcyclohexane, Ethylcyclohexane, decahydronaphthalene) or in one

aromatic hydrocarbons with 6 to 11 carbon atoms (benzene, toluene, ethylbenzene, om- and y-xylene, 1,2,3,4-tetramethylbenzene or pentylbenzene): the acetylacetonates of palladium, rhodium, ruthenium, platinum and are preferably used / or iridiums. In this case, after impregnation with the organic solution, the catalyst is expediently ^{heated to up to 500 °} C., preferably 110 to 400 ^° C., in air.

Then the impregnation with rhenium is carried out, as in the case of the impregnation in aqueous solution.

The rhenium compound must be soluble in the impregnation solvent: e.g. are rhenium heptoxide and ammonium perrhenate, among other things, compounds that fix the rhenium on the catalyst from an aqueous impregnation solution are useful.

The carrier can be of various types, as already mentioned above. A particularly suitable carrier possesses specific properties, such as a specific surface area, which is determined using the B E T method,

ρ ρ

from 10 to 500 m / g, preferably 50 to 500 m / g, and a total porous volume of 50 to 130 cnr per Ί00 g carrier, preferably 80 to 110 cnr per 100 g carrier. It should be noted that the use of a carrier whose specific upper

area is less than 50 m / g, simply use a less active catalyst to produce this catalyst delivers, but the selectivity of the conversion remains at least equivalent. If you use on the other hand, the finished catalyst has a carrier with a porous volume smaller than 50 cm * per 100 g with the same specific surface a

equivalent activity, but the selectivity is considerably lower

As soon as the two metals are fixed on the support, the catalyst is preferably subjected to an activating treatment with hydrogen at a high temperature, for example 500 to 550 ^° C., in order to obtain an active metal phase. The method of hydrogen treatment consists, for example, that is allowed to rise slowly under a stream of hydrogen up to the maximum temperature of the reduction temperature which is 300, after which holds up to 55O ⁰ C, preferably 350 is up to 450 ⁰ C one to six hours at this temperature * If the reduction is above 55O ⁰ C and below 3

15 catalyst less active »

half 55O ⁰ C and below 300 ⁰ C is performed, is the

In certain cases, it is useful prior to activation with hydrogen has a calcination carried out in air at 350 to 55O ⁰ C. The invention is explained in more detail in the following examples without any intention that it be restricted thereto.

example 1

It should be produced from ethyl acetate in a dynamic reactor with ethyl alcohol fixed bed in the presence of a catalyst containing 0.1 wt .- # palladium and 1.8 wt .- ^ rhenium contains a silicon dioxide carrier, which has a specific surface area of 300 m / g and a pe Total volume of 90 cm *, per 100ghat.

The catalyst is produced using the so-called dry impregnation method, the volume of the impregnation solution being equal to the retention volume of the carrier; using an aqueous solution of palladium chloride and dried subsequently in an oven at 11O ⁰ C. The impregnation with rhenium is then performed by the same method of dry impregnation on the carrier, which is already impregnated with palladium chloride, and is dried; an aqueous solution of ammonium perrhenate is used. The silicon dioxide carrier, which has been impregnated with the two metallic precursors in this way, is then dried in a drying cabinet at 110 ° C. for 24 hours.

A precisely known amount of the catalyst is then introduced into the central zone of the tubular reactor, in which the hydrogenation of ethyl acetate is to take place, and before the catalytic attempt at hydrogenation with Hydrogen through progressive increase in temperature up to

Subjected to 2o to 45o ° C.

The device for the catalytic experiment is equipped with all the necessary regulating equipment and control of temperature, pressure, quantity of the batch (in this exact case: ethyl acetate) and hydrogen Mistake.

The liquid and gaseous products obtained are determined and analyzed by gas phases, chromatography.

These determinations are made 4 hours after the batch addition, so that any phenomena associated with the start-up of the catalytic converter are avoided.

β β ο * »

The reaction conditions chosen are as follows

• Hydrogen / hydrocarbon substrate ratio «5

(Mole / minor

• Spatial flow rate = 0.753j / l / hour

• Temperature «23 © to 29o ° C · Total pressure «50 bar

The results are shown in Table I zusammengestelltj The conversions and yields are in wt -.% Expressed relative to the amount of the introduced Ithylazetats and the selectivities in wt .- ^ based on the amount of the converted Äthylazetats "

The increase in temperature leads to an increase in the Activity and a decrease in selectivity, which is expressed in the increased formation of acetaldehyde.

Comparing the first and last lines of Table I. (All tests were carried out with the same catalyst sample), it is found that the performances this catalyst are stable between the first and the last line of Table I are 30 hours of functional

2o duration expired.

- Table I -

Hydrogenation of ethyl acetate - catalyst contains 0.1 ff palladium and 1.8 # rhenium

temperature
(° c) Total pressure
(Bar) conversion
(Gew, - #) selectivity
of ethanol
OO yield
Ethanol selectivity
of acetalde-
hyd (#) yield
of acetal
dehydration (#) selectivity
of hydrocarbons
fabrics (JIi) 250 5o 65, o 85, o 55.2 8.5 5.5 6.5 23O 5o 48.0 92, o 44.2 5, o 2.4 3, o 270 5o 74, o 77, o 57, o 12, o 8.9 11, o 25O 5o 66.0 86.0 56.8 9.0 6.0 5, o

ÜC ^:

example Zx

Ethyl alcohol is said to be produced from ethyl acetate, and indeed in the presence of a catalyst that is 2 wt .- # Palladium and 1.8 wt .- ^ rhenium contains · The manufacture and the use of the catalyst are identical to that in Example 1.

In this Pail one works in a temperature interval from 23o "to 29o ° 0 and a pressure range from 1o to 5o bar ·

The results are compiled in Table II. The following is found!

The increase in temperature also increases the activity, but reduces the selectivity in the same way as in Example 1.

The increase in pressure has a beneficial effect on activity and selectivity.

The increase in the palladium content reduces the selectivity.

Example 5t

TJm to show that it is absolutely necessary to use a catalyst which is a noble metal and at the same time Contains rhenium, one compares the three following catalysts, which are made according to the method described in Example 1 made with the same Silijsiumd ^ oxide support became.

- Table II -

Hydrogenation of Ethyl Acetate Catalyst contains 2 # palladium and 1.8 ff bhenium

Temperature Total pressure
(Bar) conversion
(Wt .- #) selectivity
of ethanol yield
Ethanol selectivity
of acetalde-
hyd (#) yield
of acetal
dehydration (#) Selectivity
Hydrocarbon egg
(#) 290 5o 85, o 45.9 39.0 2o, o 17, o 34.1 27o
25o 5o
5o 77, o
58, o 66.0
7o, o 50.8
4o, 6 14.5
8.5 11.2
4.9 19.5
21.5 230 5o 45, o 80.0 36, o 7.3 3.3 12.7 27o 3o 55.2 56.2 31, o 3.5 1.9 4o, 3 27o 1o 3o, o 5o, o 15, o 5, o 1.5 45, o

- Catalyst A: content of palladium 0.1% by weight and of rhenium 1.8 wt .- #

- Catalyst B: rhenium content 2, ο #

- Catalyst C: palladium content Λ%.

In this way the total number of metal atoms in the catalyst is constant.

The three catalysts were tested under the following conditions: 23o ° C - pressure ■ 50 bar - spatial flow rate «0.75 1 ethyl acetate per 1 catalyst 1ο and per hour ·

The results are summarized in Table III %

It can be seen that both palladium alone and aucriRhenium alone do not lead to higher yields of alcohol to lead? only through the association of rhenium and noble metal (in this case palladium) one can get good ones Yields obtained.

Example 4-;

Ethyl alcohol is to be produced from ethyl acetate according to the method described in Example 1, but palladium is replaced by iridium, platinum, rhodium and ruthenium. The content of the second metal associated with rhenium is 0.1 # for rhodium and ruthenium, 0.2 $ for platinum and iridium, so » that one has the same atomic number of noble metal on the carrier. The impregnation of the platinum is carried out by a Solution of hexachloroplatinic acid carried out, that of iridium with a solution of hexachloridium acid, that of rhodium with a solution of rhodium trichloride and that of ruthenium with a

Solution of ruthenium trichloride · Die in the hydrogenation Results obtained from ethyl acetate are shown in Table IV. The test conditions are identical to example 3: temperature 23o ° C, pressure β 5o bar and spatial flow rate (WH) a 0.75 1 ethyl acetate per liter of catalyst and per hour

- Table III -

Hydrogenation of ethyl acetate in the presence of
the following catalysts:

A: 0.1 # Pd and 1.8 % Ee on silica
B: 1.8 # Re on silica
C: 1 # Pd on silica

!Catalyst conversion
(Wt .- #) selectivity
of ethanol
(*) yield
Ethanol
*) selectivity
of acetalde-
hyd Oi) yield
of acetal
dehydration (#) Selectivity
Hydrocarbons A. 48 92 44.2 5 2.4 3 B. 5 8o 4th - - 2o C. 15th 7o
! 1o, 5 8th 1.2 22nd

3217423

All catalysts resulting from an association of rhenium with a transition metal from the group Platinum, iridium, rhodium and ruthenium show activity similar to that of the Association Palladium-rhenium is equivalent · It should be pointed out that the associations with which the best selectivities can be obtained in the following series: palladium-rhenium, platinum-rhenium and Rhodium-rhenium

Io Table IV

Hydrogenation of Ethyl Acetate in the Presence of Catalysts with _which Rh _A Irr Ru or Pt is associated.

metal conversion
(Wt .- ^) yield
Ethanol
(Wt .- #) yield
Acetaldehyde
hyd selectivity
of hydrocarbons
substances (wt .- #) Rh 45 4o, 5 1.3 7th Ru 42 36 o, 6 13th Ir
(o, 2) 46 4o 1.0 11th Pt (o, 2) 47 42 1.8 6.8

Example 5

Ethyl alcohol is to be produced by hydrogenating j & thyl acetate under the test conditions of Example 3 in the presence of a catalyst according to the invention which contains 0.1 % palladium and 5 % rhenium

54 # ethyl acetate are converted; be against it Hydrocarbons in the amount of 22 JIi of the formed Reaction products recovered · The increase in conversion due to a higher metal content thus leads to a reduction in selectivity due to the breakdown of the alcohol formed into the hydrocarbon

Example 6

It is said to be ethyl alcohol made from ethyl acetate among the same Conditions as in Example 3 can be established. The catalyst has a palladium content of 0.1 Wt .- # and a rhenium content of 1.8 wt .- #. Man uses silica as a carrier with various properties. The results are in Table V compiled.

The increase in the support surface does not lead to an increased activity but to a reduced one Selectivity.

The use of a carrier with a smaller surface area does not harm the selectivity, but leads to one decreased activity.

- Table V -

Activity and selectivity of catalysts that o, 1 % Palladium and Contains 1,8 # rhenium on various silicon dioxide carriers

carrier Porous
volume
(cm3 / g) conversion
(Wt .- #) selectivity
of ethanol
OO yield
Ethanol
W. selectivity
of acetalde-
hyd (Jf) yield
to Aze-:
taldehyde
(*) Selectivity
Hydrocarbon
fabrics (#) Specific
surface
(Flat) o, 45
0.80
o, 9o 45
25th
48 80
92
92 36
23
44.2 7th
8th
5 3.15
2
2.4 13th
<o, 1
3 45o
4o
3oo

Example 7

Ethyl alcohol is said to be produced from ethyl acetate in the presence of a catalyst based on palladium and rhenium, which are based on an aluminum oxide with the following properties

The following are deposited: specific surface area equal to 150 m / g and porous volume equal to 9o cnr per loo g of support. Prior to the reduction at 4-5o C. ₉ conducted in the reactor prior to the catalytic test "Io is one-half of the catalyst is subjected to a calcination in air at 5oo ° C.

The reaction conditions are as follows!

- Temperature s 23o ° S

- Pressure ϊ 50 bar

- V V H! 0.75 1/1 catalyst / hour

- Table VI -

sample conversion
(Wt .- #) selectivity
of ethanol
CO yield
Ethanol
CO selectivity
of acetalde-
hyd (#) yield
To acetone
aldehyde Selectivity
Hydrocarbon
fabrics OO Calci
ned
and At
close
eating
redu
adorns 52 91 47.3 7th 3.6 2 Redu
adorns
without
Calci
nier
ung 12th 7 ^ 8.9 12th 14th

By using alumina you can get slightly better performance than using silica used as a carrier. However, one must calcine the catalyst in order for it to be a satisfactory one Has activity.

Example β

It is said to be decanol-1 from ifchyl deeanoate or oaprate be prepared, in the presence of the same catalyst as in Example 2 and below the reaction conditions of Example 3

The weight distribution of the various products obtained after the reaction is as follows:

-Ethyl decanoate: 4 ο #

-Decanol-1: 38.5 % 15 -Decanal: 6 #

- Ethanol: 11.5 %

- Hydrocarbon: 4 %

Example 9

The same reaction as in Example δ can be carried out in a Grignard-type reactor or an autoclave 23 ° 0 can be carried out under a hydrogen pressure of 50 bar.

After a 250 ml autoclave has been charged with 5 g of catalyst (palladium and 1.8 % rhenium), the reactor is flushed through with hydrogen.

After a hydrogen pressure of 5 atmospheres has been set in the reactor, the mixture is heated 25o ° C: The temperature is maintained for 2 hours.

After cooling down and lowering the reactor pressure to normal pressure, ethyl caprate is injected into the Injected into the reactor. A hydrogen pressure of 5 bar is then set in the reaction medium The reactor temperature is then set to a3o ° C and the The reactor pressure is then set to 5> o bar:

After 6 hours of testing, the conversion is 80 % and the selectivity of alcohol (decanol + ethanol)

° A %. The yield of 1-decanol is 76 #

Claims (9)

Expectations Process for the preparation of an alcohol, wherein one comprises an ester of an organic carboxylic acid treated with hydrogen in the presence of a catalyst, characterized, that the catalyst contains rhenium and at least one noble metal of group VIII on a support. 2. The method according to claim 1, 1o characterized in that that the rhenium content 0.5 to 5 wt .- ^ and the content of a noble metal of Group VIIX is 0.01 to 3 wt .- ^. 3 · The method according to claim 1, 15, characterized in that that the rhenium content is 0.5 his 3 wt .- ^ and the Group VIII noble metal content is 0.1 to 1 wt .- ^. 4 ·. Process according to claims 1 to 3 »2o characterized in that that palladium is chosen as the noble metal of group VIII 5 · Process according to claims 1 to 4 ·, characterized, that the support has a surface area of 10 to 500 m ² / g and a porous volume of 0.5 to 1.3 cm ^ / g. 6. The method according to claims 1 to 4, characterized in that that the support has a surface area of 50 to 500 m / g and a porous volume of 0.8 to 1.1 cnP / g bat * 7. Process according to Claims 1 to 6, characterized in that aluminum oxide is selected as the carrier. 8. Process according to Claims 1 to 7 * characterized, 1o that the pressure is 10 to 100 bar and the temperature 150 to 30O ⁰ C. 9. The method according to claims 1 to 7 » characterized, that the pressure is 30 to 80 bar and the temperature 15 180 to 25O ⁰ C. 1o. Process according to claims 1 to 9 »characterized in that that the hydrogen / ester molar ratio is 2: 1 to 10: 1.