FR2463114A1 - PROCESS FOR THE PRODUCTION OF SATURATED ALIPHATIC MONOCARBOXYLIC ACIDS - Google Patents

Abstract

THE PRESENT INVENTION CONCERNS A PROCESS FOR THE PRODUCTION OF SATURATED ALIPHATIC MONOCARBOXYLIC ACIDS. ACCORDING TO THE INVENTION, THIS PROCESS FOR THE PRODUCTION OF ALIPHATIC MONOCARBOXYLIC ACIDS HAVING FROM 6 TO 9 ATOMS OF CARBON BY OXIDATION OF THEIR CORRESPONDING ALDEHYDES IS CHARACTERIZED IN THAT IT CONSISTS OF USING AS A CATALYST THE COOKING COMPOUNDS AND SOLUBE COMBINATION COMPOUNDS. IN THIS ACID, THE MOLAR RATIO OF MANGANESE TO COPPER IS BETWEEN 0.5 AND 5. THE INVENTION APPLIES IN PARTICULAR TO THE PRODUCTION OF SATURATED ALIPHATIC MONOCARBOXYLIC ACIDS.

Description

The present invention relates to an improved production process

  saturated aliphatic monocarboxylic acids having from 6 to 9 carbon atoms by oxidation of their corresponding aldehydes using a combination of copper and manganese catalysts which are soluble in the acids produced. The acids produced by the process according to the invention are generally used in the production of esters useful in the field of

  tinctures, artificial flavors, perfumes and the like.

  Recently, a very specific interest has developed in the production of heptanol and nonanol esters which are used as raw materials for blending.

  synthetic lubricating oils.

  The acids produced according to the invention which have an even number of carbon atoms are frequently found in nature in substantial amounts whereas the acids having an odd number of carbon atoms are not generally found in nature in significant amounts. . In general, it is not easy to produce monocarboxylic acids having from 6 to 9 carbon atoms from natural materials and this is in any case very expensive. It is therefore desirable to use petrochemical means giving good yields in the production of these acids from starting materials

  hydrocarbon readily available.

  For the production of the saturated aliphatic monoxarboxylic acids according to the invention, the starting materials may be olefins having from 5 to 8 carbon atoms which, by formylation, are converted into aldehydes having from 6 to 9 carbon atoms; these last are

  then catalytically oxidized to their respective acids.

  Formylation and oxidation processes for producing acids are well known in the prior art. What is sought in these processes are improved catalysts for obtaining good yields of acids and

  high efficiency of transformation into acids.

  In the oxidation of aldehydes to acids, many catalysts are known including catalysts

  nitric acid oxidation and metal catalysts

  such as manganous acetate, cobalt acetate and cupric acetate, among others. For example, manganous acetate is known to be used on an industrial scale in the production of acetic acid from acetaldehyde. Japanese Patent No. 5233614,

  published on 14 March 1977, describes the use of a combination

  its acetate of manganous acetate and cupric acetate as catalysts in the oxidation of acetaldehyde to acetic acid. The reason for using a combination of manganese and copper catalysts is to

  reduce the amount of impurities produced, especially

  formic acid. It has been found that manganous acetate alone as a catalyst for the production of acetic acid from acetaldehyde is as effective in the conversion of the aldehyde to the desired acid and the acid yield as the combination of of manganous acetate and cupric acetate. It is also avoided using the manganous acetate only certain disadvantages of such combinations, for example increased corrosion and pump sealing defects due to copper deposits. Comparative tests have shown that manganous acetate alone does not lead to a greater loss of efficiency by formation of formic acid in the oxidation of acetaldehyde to acetic acid than the combination of manganous acetate and acetate cupric. In addition, the use of manganous acetate as a catalyst makes it possible to obtain results substantially similar to those obtained when a combination of manganous acetate and cupric acetate is used as catalyst in the oxidation of propionic aldehyde. propionic acid

  and valeraldehyde to valeric acid.

  However, the production of acetic acid from acetaldehyde is different from the production of acids having at least 6 carbon atoms from their corresponding aldehydes in that the oxidized atom in the oxidation of acetaldehyde is the atom of carbon related to

  the oxygen atom which is further bound to a methyl group.

  The presence of the methyl group results in more stable reaction intermediates than with aldehydes having 4 or more methylen groups between the carbon atom bonded to the oxygen atom and the methyl group. Products, among others, that can be produced by oxidation of acetaldehyde include acetic acid, methyl acetate, formaldehyde, methyl formate, formic acid, carbon dioxide, carbon monoxide , methane and water. On the other hand, the products that can be produced in the oxidation of heptanal, for example, include most products produced by oxidation of acetaldehyde plus heptanoic, hexane, hexene, hexanal, hexanol, hexanoic acid, valeric acid, butyric acid, propionic acid, and many

  esters, aldols and lactones, among others.

  Cupric acetate alone is an oxidation catalyst

  acetaldehyde to acetic acid, but the efficiency of the conversion of aldehyde to acid with this catalyst is significantly lower than that of manganous acetate. Contrary to what has been observed in the oxidation of acetaldehyde and of propionaldehyde, the use of manganous acetate alone in the oxidation of aldehydes having a higher number of carbon atoms, such as heptanol, provides aldehyde conversion rates (70-75%) too low to achieve a transformation efficiency of the aldehyde into sufficient acid, which requires recovery of the aldehyde which has not not reacted by distillation for recycling in the case where this process is commercially feasible. In addition, significant losses of aldehyde occur by condensation at high boiling point products between 150 and 2000C in the recycle column.

aldehyde.

  An improved catalytic process for the production of aliphatic monocarbocylic acids having 6 to 9 carbon atoms has been discovered by oxidation of their corresponding aldehydes. This process uses as a catalyst a combination of manganese and copper compounds which are soluble in the acids produced. The manganese and copper compounds can be used in amounts such that the mole ratio of manganese to copper is between 0.5 and 5. The aliphatic monocarboxylic acids having from 6 to 9 carbon atoms which can be produced by the process according to the invention comprises hexanoic produced from hexanal, heptanoic from heptanal, octanoic from octanal

  and nonanoic from nonanal.

  The process according to the invention makes it possible to achieve a transformation efficiency of aldehyde into a high and commercially attractive acid at a high aldehyde conversion rate (80-90%). Since the efficiency of the aldehyde conversion to the acid and the conversion rate of the aldehyde are high, a single-stage liquid phase reactor can be used satisfactorily. The process according to the invention also allows the use of a two-stage liquid phase reactor in which the mixture containing unreacted aldehyde in the first stage of the catalytic reaction can pass into a second stage of catalytic reaction, which achieves conversion rates of

  the aldehyde of 97% or more with a conversion efficiency of

  addition of the aldehyde to 90% or more acid. With a two-stage liquid phase reactor, the unreacted aldehyde recycle operation is generally not

not necessary.

  In the single-stage liquid phase reactor and in each stage of the two-stage liquid phase reactor, the reaction may be conducted at a pressure of between 1.4 and 10.5 kg / cm 2, preferably between 6 and 6, 4 kg / cm2, with air at a temperature included

between 500C and 800C.

  Air is commonly used as a source of oxygen,

  although pure oxygen can also be used.

  Oxygen must be supplied in at least stoichiometric

  metric to convert the material to be oxidized to carboxylic acid and compensate losses by producing derived products such as carbon dioxide. The ratio of the total amount of oxygen supplied to the total amount of starting organic material is a very variable number which depends on the specific composition of the starting materials provided, the desired products, and other factors inherent in the process. Typically, the oxygen-containing gas is packaged through the liquid reaction mixture in an amount sufficient to prevent the lack of oxygen that may be indicated by low oxygen concentration or a high ratio of carbon monoxide. carbon with respect to carbon dioxide, or both, in the exhaust gas. The oxidation reaction can be conducted in liquid phase, i.e. the aldehyde to be oxidized is in liquid form. Typically, the aldehyde serves as the solvent in which the reaction takes place. The problem of the separation of water in oxidation reactors arises when the nonanal is oxidized but not during the oxidation of the heptanal. Water can extract and precipitate

  the catalyst by reducing its efficiency by about 2%.

  The phase separation does not occur when acetic acid is added to the nonanal so that there is in the reaction liquid about 2% by weight of acetic acid. The residence times in the reactor may be between 0.1 and 5 hours, preferably between 0.3 and 1 hour. The residence time is calculated as follows: volume of laslton in the residence time = the solution of the aldehyde addition rate The catalyst can be formed by combining any copper and manganese compounds which are soluble in the acids of which they allow production. The preferred compounds are manganous and cupric soluble salts, more particularly manganous acetate and cupric acetate. Each of these compounds can be present in catalytic amounts during the oxidation, amounts of between 10 and 2,000 parts per million of manganese and copper, preferably between 200 and 600 parts per million based on the weight of the liquid reaction medium. The molar ratio of manganese to copper may be between 0.5 and 5, preferably

between 1 and 3.

  The carboxylic acid can be recovered from the oxygenated reaction mixture by various means known in the art.

  occupation, and typically by distillation.

  The main difficulty of the process of the invention lies in the presence of copper compounds in the product obtained. When purifying the acid, copper can precipitate and cause mechanical problems such as corrosion of the reboiler and pump wheels, and pump sealing defects among other problems. Copper and manganese can precipitate in the organic acid produced in their oxalates by the addition of oxalic acid. The oxalates can then be filtered from the organic acid produced prior to purification and recovery. Copper and manganese can also be separated from saturated aliphatic organic acids having from 6 to 9 carbon atoms by precipitating them to their oxalates by the addition of aqueous oxalic acid. The oxalates of manganese and copper are precipitated in the aqueous phase which can be easily separated from the organic acid produced. The organic acid can then

  be decanted from the aqueous phase and then purified by distillation.

  tion. This process is described in the US application

  NI 065240 filed August 9, 1979 by Frank Wood JR.

  The following examples illustrate the present invention in more detail in order to better clarify its practical embodiment, but they should in no way be considered as limiting the scope of the present invention, because many variations and modifications are

tions are possible.

Examples 1-4

  These liquid phase oxidations of acetaldehyde to acetic acid using cupric acetate as the sole oxidation catalyst are conducted in a tubular glass reactor (inner diameter: 3.8 cm, length 122 cm) with external recirculation by a heat exchanger at 3.5 kg / cm2 and 801C. A mixture of oxygen and nitrogen (molar ratio of 9 to 1) is used instead of air to facilitate measurements on the evacuated gases and

  reduce acetaldehyde losses due to inflammation.

  These tests are conducted under conditions such that the conversion rates (concentration of acetaldehyde in continuous state) are controlled by the oxygen level supplied to the reactor. After each reaction is complete, the products are batch distilled to obtain the desired products. The reaction conditions used and the conversion efficiencies obtained are indicated in

Table I.

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  ## EQU1 ## Some of the results in Table I are calculated using the following formulas: Solution Volume in Resistance Time Reactor, ml Acetaldehyde Supply Rate, ml / hr Conversion rate = oxygen Recovery rate of acetaldehyde moles 02 supplied-moles 02 evacuated x 100 moles 2 provided moles of acetaldehyde and = equivalent in the product X 100 moles of acetaldehyde supplied Conversion rate% = moles of acetaldehyde transfozDoX 100 of acetaldehyde moles of acetaldehyde provided Efficiency of% = conversion to product moles of product produced X 100

moles of acetaldehyde supplied -

moles of unreacted acetaldehyde

Examples 5-8

  These examples are carried out using conditions identical to those of Examples 1 to 4, with the exception that a combination of manganous acetate and cupric acetate is used. The results obtained are indicated

in Table II.

Table II

  OXIDATION OF ACETALDEHYDE TO ACETIC ACID USING AS CATALYST

  A MIXTURE OF MANGANE ACETATE AND COPPER ACETATE

  Example 6 8 Catalyst concentration, ppm Cu 120 120 110 123 Mn 150 150 130 116 Duration of the test, h 2.62 2.73 3.53 2.20 Feeding speed, g / l 842, 2844, 7 844.2 900.0 Oxygen supply, mol / h 14.3 13.0 11.5 11.7 Volume of the solution in the reactor, ml 500 520 550 550 o Residence time, h 0.47 0, 49 0.52 0.49 Oxygen conversion rate,% 90.2 89.1 91.1 Acetaldehyde recovery rate,% 98.5 97.4 98.4 96.2 Conversion rate of oxygen Acetaldehyde,% 98.8 98.4 97.0 92.3 * Transformation Efficiency: Acetic Acid 88.4 90.6 94.2 96.0 Methyl Acetate 1.5 1.5 1.6 0.8 Formic acid 0.3 0.2 0.2 0.2 Carbon dioxide 8.5 6.6 3.8 1.7 ra * In addition to the products listed, small amounts of formaldehyde, methyl formate, monoxide of carbon, methane and hylidene diacetate

are obtained. -

Examples 9-14

  These examples are carried out using conditions identical to those of Examples 1 to 8 with the exception that the manganous acetate (114 parts per million of Mn 2 + on average) alone is used as a catalyst. The results obtained are indicated in the

Table III.

Table III

  OXIDATION OF ACETALDEHYDE IN ACETIC ACID USING

  ACETATE MANGANEUX (114 Dpm average Mn2 +)

AS CATALYST

Example

  Recycling rate, 1 / h Test duration, h Feed rate, g / l Oxygen supply, moles / h Solution volume in the reactor, ml Residence time, h Oxygen conversion rate ,% Recovery rate of acetaldehyde,% Conversion rate of acetaldehyde,%

Transformation efficiency

  Acetate: Acetic acid Methyl acetate Formic acid Carbon dioxide 3.45, 1 0.48 86.2 98.1 97.1 92.8 1.0 0.3 4.7 3.53 9.2 0.44 91, 6 98.0 93.0, 4 0.8 0.2 2.7> 300 3.0 9.9 0.46 84.6 101.4 91.4 94.7 0.9 0.3 3 , 3> 300 3.50 14.9 0.45 76.6 99.0 99.3, 6 1.0 0.7 11.0> 300 3.50 12.3 0, 48, 0 98.8 98 , 3 87.9 1.1 0.5 8.6 4.0, 6 0.49 91.4 98.5 97.8 91.9 1.2 0.4, 1 * In addition to the products indicated, small amounts of formaldehyde, formate

  methyl, carbon monoxide, methane and ethylidene diacetate are obtained.

N _JL or- & M

Examples 15-20

  These examples are carried out using conditions identical to those of Examples 1 to 8, and the same calculations, with the exception that the manganous acetate (600 parts per million of Mn 2 + on average) alone is used as a catalyst. The results obtained are

shown in Table IV.

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(examples 5-8)

  (3) manganous acetate alone (Examples 9-20).

  Comparing the use of cupric acetate alone with the combination of cupric acetate and manganous acetate under identical conditions, it is noted that the effectiveness of the oxidation of acetaldehyde to acetic acid using the combination cupric acetate and manganous acetate is slightly better than the effectiveness of the oxidation of acetaldehyde to acid

  acetic when using cupric acetate alone.

  On the other hand, by comparing the combination of cupric acetate and manganous acetate with manganous acetate alone under identical conditions, the oxidation efficiencies of acetaldehyde to acetic acid are very similar. This result is confirmed by a 3-day test using a combination of cupric acetate and manganous acetate as a catalyst and manganous acetate alone at concentrations of 300 parts per million of copper and manganese in the reactors and, by comparison 300 parts per million manganese alone. The difference that is observed is that the unit, using the combination of manganese and copper salts, when compared to the unit using the manganese salt alone,

  shows an increased rate of corrosion and defects in

  rapid loss of pumps due to copper deposits.

Examples 21-28

  The propionic acid production by oxidation of propionaldehyde is conducted in a one-stage liquid phase reaction system. The reactor is a vertical steel pipe 153 cm long and 5.1 cm in diameter with a flanged plate attached to the bottom with

  attachment means for supplying air and aldehyde.

  There are numerous takeoff points of the product on the side of the reactor so that the height of the agitated liquid above the air bubbler can be controlled by selecting the takeoff point. The reaction liquid is continuously pumped by a centrifugal pump from the bottom of the reactor by a heat exchanger and discharged just above the surface of the liquid in the reactor. The flow rate of the pump is approximately 125 liters per hour.-The reaction temperature is controlled by controlling the flow of cooling water in the exchanger

  of heat compared to the flow of the pump.

  The product (both liquid and gas) exits through a pipe (0.6 cm) on the side of the reactor and enters a

  gas-liquid separator cooled with cold water (100C).

  The gases pass from a cold water condenser through an automatic pressure regulating valve, then a dry test counter. Liquid products are collected,

  weighed and analyzed by gas chromatography.

  The evacuated gas is continuously analyzed for oxygen by a polarographic detector and is analyzed periodically (approximately every 15 minutes) for carbon monoxide, carbon dioxide, nitrogen and oxygen by gas chromatography. . The concentrations of propionic aldehyde and propionic acid in the outgoing gases are calculated from the composition of the liquid phase having an ideal behavior. The liquid supply consists of a

  solution of 90% by weight of propionic aldehyde and 10% -

  by weight of propionic acid in which the desired amount of manganous acetate or manganous acetate in combination with the cupric acetate was dissolved. The actual weight of the liquid supplied to the reaction system is measured. The air is supplied to the reactor through a Hasting flow meter. The Hasting flow meter and the dry test counter on the evacuated stream are recalibrated each

  day with a soap bubble flow meter.

  Tables V and VI illustrate the conversion rates and efficiencies obtained in the tests in which the propionaldehyde is oxidized to propionic acid in a one-stage reactor. The pressure is 6.7 kg / cm2 and the oxidant is air. The height above the bubbler is about 60 cm. Conversion rates are controlled by the rate at which oxygen is supplied

to the reactor.

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Examples 29-36

  The production of valeric acid by oxidation of n-valeraldehyde is conducted in the same one-stage liquid phase reaction system as that described in

  Examples 21 to 28 under identical conditions.

  Tables VII and VIII illustrate the conversion rates and the efficiencies obtained. The pressure is 6.7 kg / cm2, the oxidant is the air and the height of

  liquid above the bubbler is about 50 cm.

Table VII

  OXIDATION OF N-VALERALDEHYDE TO VALERIC ACID USING A

  COMBINATION OF ACETATE MANGANEUX E + ACETATE CUIVRIQR

  (300 mm of Mn and 300 ppm of Cu Example 29 30 31 32 Temperature, C 60 60 60 60 02 evacuated, mol% 3,72 3,72 3,51 2,85 Conversion ratio of 02,% 85,16 85,15 85 , 88 88.75 Air supply rate, moles / h 24.56 21, 37 28.49 19.95 Carbon recovery rate,% 99.43 99.01 100.68 96.83 Conversion rate of valeraldehyde,% 91,13 86,16 95,15 82,54 * Efficacy,% Valeric acid 94,872 94,726 92,415 95,424 2-methylbutyric acid 0,431 0,437 0,411 0,432 Butyric acid 2,494 2,489 3,589 2.190

C02 0.927 0.931 1.594 0.681

CO 0.027 0.032 0.065

  Air supply speed, l / min 10.01 8.71 11.61 8.13 Liquid feed rate, ml / min 17.47 17.58 17.43 17.6 Reactor volume, l 1.083 1,083 1,083 1,083 N * In addition to the indicated products, small amounts of propionic acid, acetic acetic acid, levulic acid, O (C-valerolactone, methyl ethyl ketone, butanol, butyl valerate, pentanone and butyraldehyde are obtained. efficiencies are based on the.

  total of aldehyde having 5 carbon atoms.

Table VIII

  OXIDATION OF N-VALERALDEHYDE IN VALERIC ACID WITH

  MANGANE ACETATE AS CATALYST (300 ppm Mn 2+) Example 33 4 35 6 Temperature, C 60 60 60 60 02 Evacuated, Molar% 2,79 2,82 2.80 3.05 Conversion Rate 2% 88.77 88 , 76 88.87 87.78 Air supply rate, moles / hr air, moles / h 17.18 15.12 19.88 16.78 Carbon recovery rate,% 97.36 98.69 97 , 97.20 Validation rate of valeraldehyde,% 94.49 87.14 82.24 90.40 * Efficacy,% Valeric acid 90.933 93.266 94.556 92.834 2-Methylbutyric acid 0.222 0.232 0.280 0.216 Butyric acid 0.029 2.754 1.975 2.914

CO 2 1,838 1,093 0.961 1,258

CO 0.217 0.258 0.253 0.249

  Air supply rate,! / Min 7.00 6.16 8.10 6.84 Liquid feed rate, ml / min 11.75 11.57 16.80 11.57 Reactor volume, 1.083 1,061 1,061 1,061 * In addition to the indicated products, small amounts of propionic acid, acetic acetic acid, levulic acid, C-valerolactone, methyl ethyl ketone, butanol, butyl valerate, pentanone and butyraldehyde are obtained. The efficiencies are based on the. content -

  total of aldehyde having 5 carbon atoms.

  Comparing the combination of cupric acetate and manganous acetate with manganous acetate alone under the same oxidation conditions, it is noted that the acetaldehyde oxidation efficiencies in acetic acid, from propionic aldehyde to propionic acid. and nvaleraldehyde to valeric acid are very similar. The essential difference between the two catalysts lies in the fact that when using a combination of copper and manganese, the presence of copper deposits can cause corrosion problems as well as rapid leakage in the different pumps. used. These problems do not exist

  when using manganese catalysts alone.

  In the presence of copper, extensive separation techniques are required to remove copper from

  reaction system after the reaction is complete.

  Examples 37-41 These examples illustrate heptanoic production from heptanal in a one-stage process where the oxidation reactor is a glass pipe 91.5 cm long and 5.1 cm in diameter with a flanged plate attached to the bottom with attachment means for supply and product lines and a condenser at

  Mountain peak. The reaction temperature is controlled in -

  controlling the flow of water supplied to the heat exchanger with respect to the pump stream. The reaction liquid is continuously pumped by an Eastern centrifugal pump from the bottom of the reactor through the heat exchanger and discharged just above the surface of the liquid in the reactor. The flow of the pump is about 125 liters per hour which is equivalent to pump 1.6 times the

reactor volume per minute.

  The product (both liquid and gas) is discharged through a pipe 57.2 cm long and 0.6 cm in diameter

  which brings the volume of the reactor "agitated" to about 1.3 liters.

  The product (liquid and gas) passes through an automatic pressure regulating valve and into a cold water cooled gas-liquid separator. The gases pass from a condenser to cooled water in a wet test meter. Recovered liquid products are distilled

  in batches to recover the reaction products.

  Table IX indicates the reaction conditions and results obtained from these examples conducted as described above using a manganese salt alone (330 parts per million manganese on average) as a 6.3 kg catalyst. / cm2 and 50% oxygen in nitrogen as oxidant. The heptanal used is obtained by the "oxo" reaction of hexene and carbon monoxide, the heptanal containing 6% by weight of 2-methylbexanal. The catalyst solution added to the reactor contains 5% by weight of manganous acetate (or 1.12% by weight of manganese), the remainder being acetic acid

(81.6%) and water.

Table IX

  OXIDATION OF HEPTANAL IN HEPTANOIC EN

  AS CATALYST ACETATE MANGANEUX (300) nm

USING

Mn2 + in movenne)

37 38 39 40

  Temperatures, C Medium Background Feed Rates: Aldehyde C7, cm3 / min Catalyst Solution, cm3 / min Oxidant, moles / .I / h ppm Mn2 + in liquid product% by weight of water in liquid product% by weight of acetic acid in the liquid product Feed rate in 02, moles / l / h Oxygen conversion rate,% Oxygen consumed, moles / l / h Liquid residence time, mn Conversion rate of the aldehyde C7,%

* Transaction efficiencies

  formation in: Heptanolque 2-methylhexanoic Total acids C7 CO C02 Hexane Hexanal Hexanol Hexanolque Esters

80 80 80

82 81 83 83

, 00 16.30 21.80

0.50, 44 0.42 0.58 0.54 11.46

24.90 29.90

0.62 12.34

325 330 330 330

0.75 13.62

39 0.39 0.39 0.39 0.41

2.37 2.40 2.40 2.40 2.51

, 22 4.79 5.73 6.17 6.81

89.7 90.7 92.8 90.2 86.8

4.88 4.34 5.32 5.61

91

49 60 45 39 33

, 8 92.2 88.2 87.4 80.6

  76.36 3.34 79.70 0.60 2.75 4.93 2.43 1.72 3.42 2.38, 96 3.47 79.43 0.55 2.69 4.43 2.42 1.72 3.84 2.55 74.04 3.93 77.97 0.68 2.53 6.30 2.40 1.62 3, 19 2.20 74.37 4.03 78.40 0, 69 2.48 6.43 2.47 1.75 3.24 2.24 76.81 4.13, 94 0.70 2.37, 95 1.03 1.70 2.96 2.02

Example

Note: Table IX -

  * In addition to the indicated products, small

  quantities of products with high boiling points,

  lactone, ketoacid, succinic acid and propionic acid are obtained. The efficiencies are

  based on the total content of aldehyde C7.

Examples 42-47

  Table X illustrates the conversion rates and efficiencies obtained for another series of assays in which heptanal is oxidized to heptanol in a single stage reactor as indicated above in Examples 37-41 using acetate. manganous alone (300 parts per million manganese on average) as a catalyst at 6.3 kg / cm 2 and with 50% oxygen in nitrogen as oxidant. The catalyst solution added to the reactor contains 5.39% by weight of manganous acetate

  (1.21% by weight of manganese) dissolved in heptanal.

Paintings

  OXIDATION OF HEPTANAL IN HEPTANOIC EN

  USING A MANGANE ACETATE AS A CATALYST

Example

  Temperature, C Medium Background Branched aldehyde,%

Feeding speed

  tation: Aldehyde C7, cm3 / min Catalyst solution, cm3 / min Oxidant, moles / l / h ppm Mn2 + in the liquid product

42 43 44 45 46 47

67 60 63 71 62 69

62 61 65 70 66 73

3.75 3.75 5.71

21.50 18.30 16.70

0.47 0.40 0.36

4.63 4.63 4.63

6.76 5.70 7.76

, 05 15.80 14.20

0.33 0.36 0.32

4.63 4.47 4.58

280 270 265 270 290 280

Feed speed

at 02, moles / i / h 2.27

2.27 2.27

  Conversion rate of 02% 98.8 97.4 96.6 Oxygen consumed, moles / 1 / h 2, 24 2.21 2.19 Estimated residence time of the liquid, min 46 54 59

2.27 2.17 2.17

7 97.3 96.9

2.37

2.11 2.11

62 69

  Conversion rate of aldehyde C7,% * Efficiency of conversion to: Heptanoic acid 2-methylhexanoic Total acids C7 CO CO2 Hexane Hexanal Hexanol Hexanoic rstrS,% r h t Pol% ts, tgbulYion

63.8 70.6 75.9 83.3 82.5 87.8

  87.61 2.80, 40 0.24 0.55 3.28 1.24 0.44 0.96 1.18 1.18 88.00 2.80, 80.0, 24 0.63 86.84 3 , 66, 50 0.34 0.78, 89, 11, 99 0.50 1.01

3.36 2.72 4.03

1.19 1.37 1.59

0.52 0.51 0.78

* 1.13 1.20 2.93

1.16 0.91 1.10

0.34 0.96 0.80

  82.33 3.44, 77 0.36 0.97 3.92 1.05 1.03 1.50 2.85 0.04 77.37, 92 83.29 0, 63 1.15, 38 1, 95 1.85 2.41 1.65 0.00 * In addition to the specified products, small amounts of high-boiling products, lactone, ketoacid,

  succinic acid and propionic acid are also obtained.

  The efficiencies are based on the total content

of aldehyde C7.

Examples 48-49

  In a single stage reactor as described in Examples 37-41, the oxidation reaction of heptanal to heptanoic is conducted using an average of 600 parts per million manganese alone (in the form of manganous acetate) as a catalyst. In the glass reactor 5.1 cm in diameter, a stirred liquid depth of 61 cm is maintained, corresponding to a stirred liquid volume of 1.24 liter. The pressure is maintained at 6.3 kg / cm 2 and 50% oxygen in the nitrogen is used as oxidant distributed by a sintered stainless steel bubbler 316. The catalyst is supplied to the reactor in the form of a 10% solution. by weight of manganous acetate (2.24% by weight of manganese) dissolved in heptanoic acid. Table XI shows the rates of

  conversion and efficiencies for this series of tests.

Table XI

OXIDATION OF HEPTANAL IN HEPTANOIC

  BY USING THE ACETAE MANGANEUX ALONE

  (600 p2m Mn2 + on average) Example 48 49 Temperatures, C: 12.7 cm from the bottom 65 65, 6 cm from the bottom 62 62 Feed rate in catalyst solution, cm3 / min 0.31 0.25 Mn2 + ppm 600 560 feed rate of the oxidant moles / l / h 4.20 3.84 02 in the exhaust gas, mole% 4.4 4.5 Oxygen conversion rate,% 94.1 94.0 Oxygen consumed, moles / l / h 1, 88 1.72

Conversion rate of the

  dehyde C7,% 89.0 91.1 * Efficiency of conversion to: Heptanol 82, 78 81.47 2-methylhexanoic 5.09 5.03 Total acids C7 87.87 86.50

CO 0.33 0.30

C02 1.00 1.15

  Hexane plus Hexene 2.48 2.33 Hexanal 1.24 0.61 Hexanol 0.60 0.72 Hexanoic 2.21 2.99 Esters 2.69 2.66 * In addition to the products listed above, small amounts of High boiling point, lactone, keto acid, succinic acid, glutaric acid, aldol are also. obtained. The efficiencies are based

  on the total content of C7 aldehyde.

Examples 50-56

  Using the same single-stage reactor and the same conditions as those used in Examples 37-41, a series of heptanal oxidation tests in heptanoic is conducted using as catalyst a combination of copper salts and of manganese with a molar ratio of 1: 1. The catalyst solution contains 3.74% by weight of cupric acetate (1.19% by weight of copper) and 5.31% by weight of acetate

  manganous (1.19% by weight of manganese) in heptanoic acid.

  The 5.1 cm diameter glass reactor is maintained at 6.3 kg / cm 2 and 50% oxygen in nitrogen is used as the oxidizer. Table XII shows the conversion rates

  and the efficiencies obtained for these tests.

Table XII

  OXIDATION OF HEPTANAL INTO HEPTANOIC IN A REACTOR ON A SINGLE FLOOR

  USING AS A CATALYST A COMBINATION OF COPPER ACETATES

AND MANGANES

  Example 50 51 52 53 54 55 56 Agitated liquid, Height, cm 63.5 63.5 61 61 61 61 61 Agitated liquid, Volume, liters 1.30 1.30 1.14 1.24 1.24 1.24 1 , 24 Temperature, C 12.7 cm from the bottom 63 66 62 62 67 75 76, 6 cm from the bottom 67 70 66 66 70 71 80% 2-methylhexanal in the aldehyde 7.8 7.8 5,7 6.3 6.3 6.3 6.3 Catalyst feed rate, cm / min 0.35 0.33 0.30 0.22 0.17 0.17 0.17 ppm Mn and Cu 290 260 260 270 255 250 280 Oxidant feed rate, moles / l1 / h of N2 evacuated 4.43 4.72 4.13 3.61 3.62 4.22 4.40 Oxygen evacuated, mol% 3.0 3.3 3, 8 4,4 3,0 3,0 2,3 n 18'ú 8qlç6'Z 8Z'úç 61'Z 8ú'l 1 úZ 'II00 1 onb or'exGH f 00'0 00'0 6' 0 91 ' 0 úL60 00'0 91'0 IouexeH you Z7t 'I'L 1UL 460 1940 56'0ú6'0 IeuexeH 19'0 The 0990 L5'0 / 0S'O 99'1 L9'4auexeq SNLD had "XEH

  úZ'Z Z6 '1 9' 1'0 69'0 95'0 99'0 OD

  6ú'0 9Z'0 9Z'0 5Z'0 9Z'0 Lú'0 0ú'0 0O

  06'Ze 8ZO'5 99 '99U' L16 99'Z6 LS'Z6 9ú'Z6 sepToU the 40% o 06'9t L6 '0U' S LU 'ZS 5 5 88 9 90 L-Z onblouededqXlqgm 00'89L 0'08 9c'9 9S '1 9L5L9 69' 9 Zu '58 enblouBdeH: ap uoTemaossueal ap s9% ToeoT $ H * 0'96 4'96 0'ú6 1'06 0'189 The 9'Z%' 40 epXgqPpltl ap uolsaGAuoo op xnvl q 'epTnbTt' Z S'Z S'Z O'1, ZL 8 'I. ú'l 1 np', amfi ^ se cm eouepTsga ap sdmel L0 Z ú6'1 99 'I 9' '' II'Z Zl Z gnosA9 ZN years gssq q / I / salom gumosuoo euqs xo 9'96 6'56 1'96 '96 Z'56 Z'96 9'96.gnoeAg ZEN ns gseq% 'eut2xoI ap UOTsaeAU00 op xnel 55 '5 ú5 z5 15 05 eldmxz xISvM-O mm' nOlAImIno smmvmIv, NOSIYvNIENo MM undxSIVIVO 'M "oo mNvSIzInii NZ ZoVIS nIS nn v ENSovE Nf SNYr SMIONMSH N21 7 VNvdaHi N ozmvsxo 4eUns) IIX nealqv Note Table XII

  * In addition to the products listed below

  above, small amounts of high-boiling products, esters, lactone, ketoacid, succinic acid, glutaric acid, aldols are also obtained. The efficiencies are based on the total content

  of the aldehyde having 7 carbon atoms.

  In Examples 37-56, there is a direct comparison between the oxidation of heptanal to heptanoic using a manganese salt alone as a catalyst and a combination of manganese salts and copper as a catalyst. The use of manganese salts alone as an oxidation catalyst for the production of acetic acid from acetaldehyde, propionic acid from propionaldehyde and valeric acid from n-valeraldehyde provides efficiencies. high aldehyde to acid conversion for high aldehyde conversion rates. However, it has been found that when the carbon content of the aldehyde increases,

  the efficiency of the transformation into acid decreases rapidly

  for high aldehyde conversion rates. For example, the conversion efficiency of heptanal to acid containing 7 carbon atoms is 90-91% for an aldehyde conversion rate of about 75% and drops rapidly to 86% for a conversion rate. 82% aldehyde. The low conversion rate of heptanal for high acid conversion efficiencies (70-75%) with recovery of unreacted aldehyde (by distillation), requires a recycling procedure to obtain better yields . The use of a combination of manganese and copper salts for the oxidation of heptanal to heptanoic makes it possible to achieve an efficiency of conversion to an acid having 7 carbon atoms of between 90 and 93% at a conversion rate of the aldehyde of between 80 and 90%. The results of the combination of manganese and copper salts in the oxidation of heptanal are significantly better than the results obtained when using a manganese salt alone. The use of a combination of manganese salts and copper allows the use of a second stage reactor to convert the small amount of unreacted aldehyde into

  the desired heptanoic without using a recovery system

  and recycling of aldehyde. This is demonstrated in the following examples

Examples 57-59

  In these examples, it is demonstrated that heptanal can be oxidized to heptanic acid at aldehyde conversion rates between 94 and 98% with high acid conversion efficiencies, using as a catalyst a combination of manganese salts. and copper in a two-stage reactor. This process uses two reactors in the form of glass pipes 244 cm long and 5.1 cm in diameter in sequence where the first stage converts the heptanal in the proportion of 80 to 86% for a reactor height of 117 cm. (2.37 liters), and the second stage has a reactor height of 76 cm (1.54 liter) receives the first stage reaction product for subsequent conversion of the unreacted aldehyde to that an aldehyde conversion rate of 95 to 98% is obtained. The reaction conditions for the two stages are: a pressure of 6.3 kg / cm 2, the oxidant consisting of 50% oxygen in the nitrogen distributed in the first stage by a capillary bubbler of 0.43 mm diameter and in the second stage by a capillary bubbler 0.18 mm in diameter. The catalyst solution contains 4.45% by weight of manganous acetate (1% by weight of manganese) and 3.14% by weight of cupric acetate (1% by weight of copper) dissolved in heptanoic acid (density 0.918) and is added to the first stage of the reactor only. The flow

  of the pump is 1.98 liters per minute.

  Using this method, high efficiencies of heptanoic transformation are achieved without using a recycle operation as shown in Table XIII which indicates the conversion rates and efficiencies obtained in these examples. The results for the conversion rates in the first stage are estimated on the basis of the content of aldehyde having

7 carbon atoms.

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  ú5 'Z (Z5) (Z) (15G) (ú) (ú5) (ú5) (05) (ú5) SMlIHAIlo ZVtsovaG & XfiNVDNV & VavIsa NOSIVYNINOD MM INVSI'Ilfi NZ xOVIZ XaSCI V Uf aatDVY Nfl SNVYC MLOIONVIH NM' IVNVtdgHs NOIVGXAXO IIIX neelqu Table XIII (continued)

  OXIDATION OF HEPTANAL IN HEPTANOIC IN A REACTOR WITH TWO FLOORS IN

  USING A COMBINATION OF MANGANE ACETATE AND COPPER ACETATE

  Example 57 8 9 * Processing efficiencies,% of: Total acids C7 88, 06 87.01 87.12

CO 0.07 0.10 0.07

C02 0.52 0.70 0.76

  Hexane, hexene 0.78 0.67 0.71 Hexanal 1.11 1.09 1.11 Hexanol 0.20 0.20 0, 22 Hexanolque 2.16 2.54 2.81 Total C7 acid yield 83.8 83.6 84.3 from heptanal * In addition to the products listed above, small amounts of esters and light products are obtained. The efficiencies are based on the total content of aldehyde

having 7 carbon atoms.

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Table XIV

  OXIDATION OF HEPTANAL IN HEPTANOIC IN A REACTOR WITH TWO FLOORS IN

  USING A COMBINATION OF ACETATES OF

MANGANESE AND COPPER

  1st 2nd floor floor Temperatures, C 12.7 cm from the bottom, 6 cm from the bottom Feed rate of the aldehyde C7, cm3 / Jn Feed rate in catalyst cm3 / min ppm Mn and Cu feed speed Oxidizer, mole / I / h based on N2 evacuated Oxygen evacuated, mol% Oxygen conversion rate,%, based on N2 evacuated Oxygen consumes, molest / h based on N2 evacuated Estimated residence time, h combined

66 65

65

11.80 ---

0.29 ---

--- 290

3.44

7.6 13.1

, 5 ---

1.48 ---

4.61 82.3 1.81

1.7 1.8

1st 2nd En-

floor floor sefbf

66 65 ---

65 ---

13.40 ---

0.33 ---

--- 285 ---

  3.87 7.4 91.8 4.75 3.9 94.8 1.76 2.25

1.4 1.6

1st floor 2nd floor

66 66

65

13.50 ---

0.34 ---

--- 295

3.82 ---

6.8 5

92.0 ---

1.78 ---

--- 1.4

1.3

Example

  Total 4.81 93.7 2.25 4 - Table XIV (cont'd)

  OXIDATION OF HEPTANAL IN HEPTANOIC IN A REACTOR WITH TWO FLOORS

  USING A COMBINATION OF MANGANESE AND COPPER ACETATES

Example 60 61 62

  1st 2nd En- 1st 2nd En- 1st 2nd En-

  floor floor seems floor floor seems floor floor seems Conversion rate of aldehyde C7 89.1 9.0 98.7 84.7 13.0 97.7 84.7 12.7 97.0 * Processing efficiencies,% of Heptanol 84,59 --- 83,29 85,94 - 82,58 86,22 --- 85,68 * 2-Methylhexanoic 5,52 --- 5,15 5,87 --- 5,57 5, 72 --- 6.39 o Total acids C7 90.11 72.2 88.44 91.81 63.6 88.15 91.94 84.9 91.07

  CO 0.33 --- 0.32 0.32 --- 0.29 0.39 --- 0.37

  C02 0.55 --- 0.97 0.36 --- 0.77 0.38 --- 0.70

  Hexane plus hexene 1.13 - 0.83 1.76 --- 0.95 1.84 --- 1.02 Hexanal 1.03 - 1.00 0.91 --- 0.91 1.00 - - 1.00 Hexanol 0.24 ---. 0.22 0.24 --- 0.22 0.00 0.09 Hexanol 1.86 --- 1.91 1.24 --- 2.50 1.29 --- 1.40 * in addition to the products indicated above, small amounts of products àhauts boiling points of light products, esters, pentanolque acid, butyric acid, propionic acid, acetic acid, lactone, keto acid, succinic acid, glutaric acid and aldols are obtained. The efficiencies are based on the content of

  the aldehyde having 7 carbon atoms.

tW w mb

Examples 63-68

  In these examples, it is shown that nonanal can be oxidized to nonanoic very efficiently at aldehyde conversion rates between 91 and 97% with high acid conversion efficiencies, using as a catalyst a combination of manganese and copper in a two-stage reactor

  The two-stage reactor used is identical to the

  used in Examples 57-59 for the oxidation of heptanal to heptanol. It comprises two 5.1 cm diameter glass tube reactors sequentially in which the reaction medium in the first reactor stage is maintained at a height of 117 cm (2.37 liters) and the reaction medium in the reactor. The second reactor stage is maintained at a height of 76 cm (1.54 liter) The pump flow rate is 1.98 liters per minute The catalyst solution used contains 2.81% by weight of manganous acetate ( 0.36% by weight of manganese) and 1.98% by weight

  of cupric acetate (0.36% by weight of copper) in one.

  mixture of 43% by weight of acetic acid and 52.2% by weight of nonanol. Acetic acid is used to facilitate the solubilization of manganese and copper salts. Both stages are maintained under a pressure of 6.3 kg / cm2 and 50% oxygen in the nitrogen is used

as an oxidizing gas.

  The results of these examples are shown in Table XV. The results of the first stage conversion rates are estimated on the basis of the content in

  aldehyde having 9 carbon atoms.

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(ú5) (Z5)

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(17) (ú)

(ú5) (1g)

(ú) (ú5)

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(ú9) (09)

(09) (9) (9) (Z9)

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  (a2ea.9 Z) (ea2e.9 Ja e) puo $ np mo 9'Q0 (e9B1.9 qZ) (ee (9 aa e)

puo; np mo The Z-

  : 00 'eJnelapdmwe eIdmexz W. M 9'96 li8 ú' G6 ú'Z8 '1 8' 06 9L 8'98 1'96 f8 The 0'178 0'i7 Z'5 9'9Z '6'8 86' G - 9'5Z 1.1. ' g8 1. 9 'GZ (ú5) (1) (ú5) (kg) 9'8eZ

(U)) (Z5)

89 L9

  aflOIHAIflo aSVIZDYS. the XFLMKNUO SIVSLaDVaU NOSIYNIEO: D Mf LNVSIIIf N: SODVIS xnMa CV UflUSDVEU Ni SNVIa SlOIONYON N. 'IVNVNON Ef NOIIVCIXXO AX' V nBaiq ú'Z Table XV (continued)

  OXIDATION OF NONANAL TO NONANOIC IN A REACTOR WITH TWO

  USING A COMBINATION OF MANGANE ACETATE AND ACETATE

STAGES IN

COPPER

Example

63 64

  * Transformation efficiencies,% of: Nonanoic 82.83 83.15 82.80 84.03 83.07 2-.methyloctanoic 3.48 3.52 3.55 3919 4.06 Total acids C9 86.31 86.67 86.35 86.21 87.13

CO 0.08 0.07 0.00 0.00 0.00

C02 0.76 0.67 0.57 0.75 0.70

  Octane and Octane 1.31 1.49 1.90 1.46 1.50 Octanal 1.60 1.69 1.64 1.66 1.74 Octanol 0.53 0.62 0.70 0.59 0.50 Octanoic 2,53 2,49 2,21 2,37 2,52 * In addition to the products mentioned above, small amounts of light products, esters and aldols are obtained. The efficiencies are based on the total content

  of the aldehyde having 9 carbon atoms.

  6 ..., 42 3,10 88,52 0,00 0,63 0,65 1,36 0,20 2,01 N o% tg 4b Of course, the invention is in no way limited to the embodiments described which have been given only as an example. In particular, it includes all the means constituting technical equivalents of the means described, as well as their combinations if they are executed according to its spirit and implemented in

  the framework of the claimed protection.

Claims (4)

R E V E N D I C A T I 0 NS   1. A catalytic process for producing aliphatic monocarboxylic acids having from 6 to 9 carbon atoms by oxidation of their corresponding aldehydes, characterized in that it consists in using as catalyst a combination of soluble manganese and copper compounds in said acid, the molar ratio   copper manganese being between 0.5 and 5.   2. Process according to claim 1, characterized   in that heptanoic acid is produced from heptanal.   3. Process according to claim 1, characterized   in that the nonanoic is produced from nonanal.   4.- Method according to one of the claims   characterized in that the copper and manganese catalyst consists of a combination of cupric acetate and manganous acetate and in that the ratio   The molar ratio of manganese to copper is between 1 and 3.