DE2643971A1 - PROCESS FOR THE PRODUCTION OF ALKANE POLYOLS - Google Patents

Description

concerning

Process for the manufacture of alkanepole voles

The invention relates to the production of alkane polyols, in particular of ethylene glycol in the further development of the Process according to US Pat. No. 3,833,634 and an earlier one Registration (USSN 462 109 of April 18, 1974).

These older processes relate to the reaction of hydrogen with carbon oxides in the presence of rhodium carbonyl complexes as catalysts for the production of the alkane polyols mentioned. In another older application (USSN 537 885 of 2.1.1975) the production of alkane polyols with the help of rhodium carbonyl complexes takes place in one homogeneous liquid phase using tetramethylene sulfon as the main solvent. The main advantage of the

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use of a solvent in this older process
the reduction of catalyst losses. According to an older proposal, tetraglyme has also been used as a solvent in a process in a homogeneous liquid phase (tetraglyme is the dimethyl ether of tetraethylene glycol). It was surprisingly found that
by using a mixture of tetraglyme and sulfolane, higher degrees of conversion to alkane polyol can be obtained and, if appropriate, under more favorable process conditions
and higher temperatures can work if this is the case
if you only use tetraglyme or sulfolane as solvents.

The use of this solvent mixture in the reaction in a homogeneous liquid phase under any working conditions results in higher yields of ethylene glycol than with the
same working conditions using only one
this solvent _{ while all other ingredients including promoters are the same. It is also advantageous in the process according to the invention that the rate constant increases with increasing reaction temperature
the formation of alkane polyols increases. Another advantage is
that this mixture reduces possible adverse effects which can occur when only sulfolane is used at these temperatures as the only solvent in terms of instability which affects the catalyst activity
adversely affected.

The inventive method is carried out mperaturen T _e and printing in accordance with the aforementioned patents
and registrations, namely at about 100 to 375 ⁰ C and pressures of 35 to 3 515 ata. The ratio of tetraglyme to sulfolane is determined by the reaction conditions. Basically
it can be said that such a solvent ratio
is sought in which the formation of alkane polyol is greater than with the individual solvents under the same conditions. 709313/1040

1A-48489

This ratio of tetraglyme to suIfolan ("solvent ratio") can be between 1:20 and 20: 1, based on the volumes. Factors like the ratio CO to Hp, temperature, pressure, concentration of the components How catalysts and promoters as well as type of promoter play some role in determining the most effective Solvent ratio. In a system, the volume ratio of tetraglyme to suIfolan can be optimal at 1, while for another system it is 2. When determining a suitable solvent ratio it is therefore necessary to check several ratios on the basis of a number of experiments in a given reaction system, in order to be able to determine optimal solvent ratios.

The term “sulfolane” here includes tetramethylene sulfone and substituted tetramethylene sulfone are the same Bring benefits. The substituted which can be used according to the invention Sulfolanes correspond to the general formula

wherein R ₁ to R _{Q is} a hydrogen atom, a hydroxyl group, a straight-chain or branched alkyl group, preferably with 1 to 12, in particular 1 to 6 carbon atoms (methyl,

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1A-48489

Ethyl, isopropyl, butyl, dodecyl, octyl), a cycloaliphatic group (including monocyclic and bicyclic groups such as cyclopentyl, cyclohexyl, bicyclo / 2,2, i2heptyl) or an aryl, alkaryl or aralkyl group (phenyl, naphthyl, xylyl , Tolyl, benzyl, ß-phenylethyl) or an ether 40-R °), where R ^{0 is} an aryl or lower alkyl group with 1 to 12, preferably 1 to 4 carbon atoms in the alkyl chain ^: i is an alkylene or Polyalkylene ethers of the formula - ( ^0C _n ^H 2n ^ x " ^0R ° ⁰ » where η is on average 1 to 4, χ is on average 2 to 10, preferably 1 to 20, in particular 1 to 4 and R °° is a hydrogen atom or an alkyl group 1 to 6 carbon atoms is (polyoxyethylene, polyoxypropylene, polyoxyethyleneoxypropylene, alkylene and polyalkylene glycols and lower alkyl ethers

thereof, a carboxylate group of the formula

wherein y can be 0 to 12 and m or m ° 0 or 1 with the proviso that when m or m ° 1 is the other index _/ and R ^{000 is} a lower alkyl group having 1 to 12, preferably 1 to 4 C atoms or an aryl group, with the proviso that not all of the substituents R ^ to R _{8 are} hydrogen atoms).

Tetramethylene sulf is preferred for the process according to the invention on or tetrahydrothiophene-1,1-dioxide. at the substituted suIfolanes are preferably in positions 3 or 3, 4.

Rhodium carbonyl complexes for the inventive method are complex compounds, of which at least one with

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-f-

1Λ-4 & 439

1) rhodium complexed with CO; 2) rhodium complexed with CO and H ₂ ; 3) Rhodium complexed with CO and at least one Lewis base and / or rhodium complexed with CO, H ₂ and at least one Lewis base.

The rhodium carbonyl complexes for the process according to the invention can be cluster compounds (P. Chini, "The Closed Metal Carbonyl Clusters", (1968), Inorganica Chimica Acta, pages 30-50), according to which a metal cluster compound is a limited group of metal atoms which is entirely or at least held together to a substantial extent by direct metal-to-metal bonding, although some non-metal atoms may also be most closely associated with the cluster. The rhodium carbonyl cluster compounds to be used in the process according to the invention contain Rh / Rh or Rh / other metal bonds such as cobalt and / or iridium. The preferred compounds are those with Rh / Rh bonds. They preferably contain carbon and oxygen in the form of a carbonyl group (-C0-), which can be terminal ₍ on the edge or in the surface. They can contain hydrogen (oxygen and carbon, but also in a form other than carbonyl). These cluster compounds can can be assigned to the following formulas

Hh ₆ (CO) ₁₆

[Rh ₁₂ (CO) ₃₀ ]

2-

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The structures of these cluster compounds can be determined with the aid of X-ray crystal analysis, nuclear magnetic resonance spectrum or infrared spectrumf "Synthesis and Properties of the Derivatives of the / Eh ₁₂ (CO) ₃₀ J ² " Anion ", P. Chini and S. Martinengo, Inorganica Chimica Acta, 3 : 2, pp. 299-302, June 1969). Particularly suitable for the analysis is infrared spectral analysis, which allows characterization of the complexes present during the conversion according to the method according to the invention.

In the complex, CO is present in complex-bound rhodium. However, in addition to the formation of the complex Hydrogen atoms and / or organic or inorganic Lewis base promoters are used one or more electron-rich molecules or atoms, which are also independently viable, with one or more Electron-poor molecules or atoms that are also independently viable. The role played by the Lewis bases in the implementation by the process according to the invention play is not yet fully understood. They can act as a ligand and / or take counterions Form reaction conditions or they can only act as Lewis bases and neutralize a special type of molecule or capture which, if left free or not bound to the base, the inventive formation of Could adversely affect alkane polyols.

Contain organic Lewis bases for the purpose of the invention at least one Lewis base Op and / or Np, which have an electron pair which is capable of a coordinative bond. So the Lewis bases 1 contain up to 4 Lewis base atoms, preferably 1 to 3, in particular 1 or 2. There are many such Lewis bases

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1A-48 489 οη, ιαη.

(2, 3 or 4 digits, depending on whether 2, 3 or 4 Lewis base atoms are included).

Lewis bases with both a nitrogen and at least one an oxygen atom are designated as aza-oxa Lewis bases.

Aza Lewis bases generally contain C, H and N atoms,

and '

Oxa Lewis bases C, H and 0 atoms, the aza-oxa Lewis bases C, H, and N atoms. The carbon atoms can be acyclic and / or cyclic, such as aliphatic, cycloaliphatic or aromatic including condensed and bridged systems. The preferred Lewis bases contain 2 to 60, especially 2 to 40 carbon atoms. The nitrogen atoms can be present in the form of the imino, amino or nitrile group. Preferred however, the imino and / or amino nitrogen group becomes. The oxygen atoms can be in the form of an alcoholic phenolic hydroxyl group, a carboxyl group, a Carbonyloxy, an oxy or carbonyl group may be included.

All of these groups contain Lewis base oxygen atoms.

in the carbonyl group and the oxy-oxygen The hydroxyl-oxygen / carbonyloxy groups are

the Lewis base atom. The organic Lewis bases can also contain other atoms and / or groups as substituents such as alkyl, cycloalkyl, aryl, chlorine or trialkylsilyl.

Examples of oxa Lewis bases are glycolic acid, methoxyacetic acid, Ethoxyacetic acid, diglycolic acid, diethyl ether, tetrahydrofuran, dioxane, tetrahydropyran, pyrocatechol, Citric acid, 2-methoxyethanol, 2-ethoxyethanol, 2-n-propoxyethanol, 2-n-butylethanol, 1,2,3-trihydroxybenzene, 1,2,4-trihydroxybenzene, 2,3-dihydroxynaphthalene, cyclohexane-1,2-diol, Oxetane, 1,2-dimethoxybenzene, 1,2-diethoxybenzene, Methyl acetate, ethanol, 1,2-dimethoxyethane, 1,2-diethoxyethane, 1,2-di-n-propoxyethane, 1,2-di-n-butoxyethane,

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1A-48 469

Pentane-2,4-dione, hexane-2,4-dione, heptane-3,5-dione, octane-2,4-dione, 1-phenylbutane-i, 3-dione, 3-methylpentane-2,4-dione; Monoland dialkyl ethers of propylene glycol, diethylene glycol, Dipropylene glycol.

Examples of aza-oxa Lewis bases are alkanolamines (ethanolamine, diethanolamine, isopropanolamine, di-n-propanolamine); Ν, Ν-dimethylglycine, Ν, Ν-diethylglycine, iminodiacetic acid, N-methyldiiminodiacetic acid, N-methyldiethanolamine, 2-hydroxypyridine, 2,4-dihydroxypyridine, 2-methoxypyridine, 2,6-dimethoxypyridine, 2-ethoxypyridine (lower alkyl such as 4-methyl-2-hydroxypyridine, 4-methyl-2-6-dihydroxypyridine), morpholine, substituted morpholines (such as 4-methylmorpholine, 4-phenylmorpholine), picolinic acid, methyl-substituted picolinic acid, nitrilotriacetic acid, 2,5-dicarboxypiperazine, N - (2-Hydroxyethyl) -iminodiacetic acid, ethylenediaminetetraacetic acid, 2,6-dicarboxypyridine, 8-hydroxyquinoline, 2-carboxyquinoline, cyclohexane-1,2 ^ dIBmIn-NjNjN ¹ , N ¹ -tetraacetic acid, tetramethyl ester of ethylenediaminetetra.

Examples of aza Lewis bases are ammonia and amines.

Primary, secondary and tertiary organic amines including the mono- and polyamines (di-, tri- and $ efe3? amines) and Lewis bases, the nitrogen atoms are part of a ring structure as in pyridine, quinoline, pyrimidine, morpholine and hexamethylenetetramine. Generally speaking, any compound is suitable which is capable of forming an amino nitrogen under the reaction conditions, such as an amide (formamide, cyanamide), urea or an oxime. Other Lewis bases with nitrogen atoms are aliphatic amines (such as methylamine, ethylamine, n-propylamine, isopropylamine, octylamine, dimethylamine, diethylamine, diisoamylamine, methylethylamine, - 71Γ9 8 T37 1Ό k 0

. λο

Diisobutylamine, trimethylamine, methyl diethylamine, triisobutylamine, tridecylamine), aliphatic and aromatic di- and polyamines (such as 1,2-ethanediamine, 1,3-propanediamine, Ν, Ν, Ν ', Ν'-tetramethylenediamine, Ν, Ν, Ν ¹ , N'-tetraethylethylenediamine, Ν, Ν, Ν ¹ , N'-tetra-n-propylethylenediamine, N, N, N ¹ , N ¹ -tetrabutylethylenediamine, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, p-tolylenediamine, o-tolidene, N, NN ¹ , N'-tetramethyl-i-phenylenediamine, Ν, Ν, Ν ¹ , N'-tetraethyl-4,4'-biphenyldiamine), aromatic amines (such as aniline, 1-naphthylamine, 2- Naphthylamine, p-toluidine, o-3-xylidine, p-2-xylidine, benzylamine, diphenylamine, dimethylaniline, diethylaniline, N-phenyl-1-naphthylamine, bis- (1,8) -dimethylaminonaphthalene), alicyclic amines (such as cyclohexylamine , Dicyclohexylamine), heterocyclic amines (such as piperidine) and substituted piperidines (such as 2-methylpiperidine, J5-methylpiperidine, 4-ethylpiperidine and 3-phenylpiperidine, pyridines and substituted pyridines (such as 2-methylpyridine, 2-phenylpyridine, 2-methyl-4 - ethylpyridine, 2,4,6-trimethylpyridine, 2-dodecylpyridine, 2-chloropyridine and 2- (dimethylamino) pyridine / quinolines and substituted quinolines (such as 2- (dimethylamino) -6-methoxyquinoline, 4,5-phenanthroline, 1,8 Phenanthroline, 1,5-phenanthroline), piperazines and substituted piperazines (such as N-methylpiperazine, N-ethylpiperazine, 2-methyl-N-methylpiperazine, 2,2'-dipyridyl, methyl- or ethyl-substituted 2,2'-dipyridyl _x 4-triethylsilyl-2,2'-dipyridyl), 1 ^ -diazabicyclo / S ^ jg / octane and methyl-substituted I ^ -diazabicyclo / S ^ jgjoctane and purine.

Examples of inorganic Lewis bases are ammonia, Hydroxides and halides, such as the chlorides, bromides, iodides and / or fluorides.

Any of the above Lewis bases can be complexed as a compound or as ligands to the Ehodiumcarbonylverbindungen dfe am en ^ a ^ d ^c o catalyst im

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Represent a reactor, be present.

The special role of rhodium carbonyl complexes such as rhodium carbonyl Cluster compounds in the reaction of hydrogen with carbon oxides to form polyhydric alcohols not yet fully elucidated. Under the reaction conditions, the carbonyl complex may be in his anionic form. As is known, rhodium carbonyl anions are formed according to the following reaction system (S.Martinengo and P. Chini, in Gazz. Chim. Ital., 102, 344, 1972).

14- '

L (CO ^

+ CO Rh ₇ (CO)

₁₆

\ s

[Rh (CO) /.,

^ electron

The infrared spectrum under reaction conditions shows the anions Rh (CO) ₄ and / Rh ₁₂ (COK ₄ ^ g_7 and other rhodium cluster compounds at different concentrations at different times of the reaction. Therefore, the reactions and equilibria shown in (V) can be show the active form des.Rhodiumcarbonyls, which is responsible for the formation of polyhydric alcohols or which is only symptomatic of intermediate and transition structures that occur during the conversion of carbon monoxide and hydrogen to polyhydric alcohols.

Assume that the active catalyst is the sodium carbonyl complex anion or that the formation of the active catalyst under the reaction conditions is direct

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depends on the existence of these anions, so with regard to the reaction rates, production and Catalyst stability the role of sulfone solvents, especially the tetra methylene sulfones, in which Explain reaction. It can be assumed that the sulfones reduce the reactivity of these complex rhodium carbonyl anions improve as a "naked" reactive anion is formed. The bare Rhodiumcaxbonyla.nions are possibly formed under the reaction conditions, since the sulfone solvent has any tendency to Reduces rhodium carbonyl anion to form an ion pair. The rhodium ca.rbonyla.nions are not strong solvated, also the rhodium is not bound in a strong complex by the solvent. This is how it comes to an anion with a higher reactivity under reaction conditions.

The method according to the invention can be carried out within a wide range of overpressure, such as about 56 to 3515 ata, prints over 3515 ata. can be used, but do not help; one prefers to go with the Pressure no higher than about 3515 ata.

In one embodiment of the method according to the invention, ma, n takes 1125 ata as the upper pressure limit. Do you do that Method at a pressure below about 1125 ata, in particular below about. 914- ata, especially under about. 562 ata through, so you only need low pressure systems, but the conversion rate at pressures is below about 843 ata. relatively la.ngsa.m and to accelerate the implementation and / or for higher implementation gra.de you need one Promoter that is a salt and / or a Lewis nitrogen base can be. In cases where the Lewis nitrogen compound is present as a lingand in the rhodium carbonyl complex added to the catalyst or where the anion of the product

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motors, which is added to the reactor, a rhodium carbonyl complex, such as cesium triacontacarbonylrhodate, it is not necessary to have additional proportions of this promoter apply. A braucn.ba.rer work pressure for a procedure using these promoters is 70 to 1125 ata, preferably 281 to 1125 ata.

In the preferred method of the present invention, the above are Print the total pressure of carbon oxides and hydrogen in the reactor.

For the method according to the invention at pressures below about 1125 ata one can use any organic or inorganic salts, as long as they allow the formation of polyhydric alcohols do not adversely affect, apply.

In a preferred embodiment of the invention Process, the above pressure data are to be understood as referring to the total pressure of hydrogen and carbon oxides in the reactor.

optionally The process according to the invention is carried out in a homogeneous liquid reaction mass in which salts are contained. Organic and inorganic salts which do not impair the formation of polyhydric alcohols are suitable as salts. The test results suggest that any salt can be advantageous as a capromotor and / or to keep the rhodium in solution during the reaction. Examples of these are ammonium salts and the alkali and alkaline earth salts (salts of metals I and II group of the periodic table) such as the halides _t hydroxides, alkoxides, phenoxides and carboxylates, in particular sodium, cesium fluoride, cesium pyridinolate, cesium formate, acetate or benzoate, cesium p-methylsulfonyl benzoate (CH ^ SO ₂ CgH ^ COO) Cs, rubidium, magnesium or strontium acetate, ammonium formate or benzoate. Preferred

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2643371

the cesium or ammonium carboxylates _r especially fanniate and benzoate w & the like. para lower alkyl-substituted sulfonyl benzoates.

Organic salts of the formulas can also be used:

II

R-,

-N-

R-.

quaternary ammonium salts

Ill

'-R _n Y

bis (triorganophosphine) iminiium salts

where R ^ to Rg are organic groups such as straight or branched alkyl groups with 1 to 20 carbon atoms (methyl, ethyl, propyl, butyl, octyl, 2-ethylhexyl, dodecyl) or cycloaliphatic groups including monocyclic and bicyclic groups (cyclopentyl, cyclohexyl, bicyclo / 2,2, i7heptyl groups) or aryl, alkaryl or aralkyl groups (phenyl, naphthyl, xylyl, tolyl, t-butylphenyl, Benzyl, ß-phenylethyl, 3-phenylpropyl) or

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Functionally substituted alkyl groups (ß-hydroxyethyl, ethoxymethyl, ethoxyethyl, phenoxyethyl) or polyalkylene ether groups of the formula ^ ^c _n ^H 2n ° ^ x ~ ^0R> where ^{n is on} average 1 to 4, χ on average 2 to about 150 and R is a hydrogen atom or a Alkyl group with 1 to 12 carbon atoms is. Such as poly (oxyethylene), poly (oxypropylene), poly (oxyäthylenoxypropylen), poly (oxyäthylenoxybutylen). Y can be any anion such as a hydroxide, halide (fluoride, chloride, bromide, iodide), a carboxylate group (formate, acetate, propionate, benzoate), an alkoxy group (methoxy, ethoxy, phenoxy), a functionally substituted alkoxy or phenoxy group (Methoxyethoxy, methoxyethoxy, phenoxyethoxy) or a pyridinolate or quinolate group. Y is preferably a carboxylate group, in particular formate, acetate or benzoate.

The production of bis (triorganophosphine) iminium salts is known (Appel, R. and Hanas, A. in Z “Anorg. U.Allg. Chem., 311, 290, 1961).

Other useful organic salts are quaternized heterocyclic amine salts (pyridinium, piperidinium, morpholinium or quinolium salts such as N-ethylpyridinium fluoride, N-methylmorpholinium benzoate, N-phenylpiperidinium hydroxide, N ₁ N ¹ -direthyl-2,2-bipyridinium acetate).

In addition to the anion of the above salts, the anions of the rhodium carbonyl complex serve as /Rhg(CO).jc 7 ", cY_7 "*» where Y is a halogen atom (chlorine, bromine, iodine)

or / Rh ₆ (CO) ₁₅ (COOR ^1! _7 ~, where R "is a lower alkyl or aryl group (methyl, ethyl, phenyl), / Shg (CO) _i4 _7 ² ~ ^{3 2}

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If the salt is added to the initial batch of the reactants, it is calculated with about 0.5 to 2 mol, preferably 0.8 to 1.6 mol, in particular 0.9 to 1.4 mol of salt per 5 atoms of Rh. In the reaction mixture

As promoters in the form of Lewis nitrogen bases ma.n use the above aza or aza-oxa Lewis bases. Preferred become amines. The nitrogen atom can be part of a hetero cycle, such as pyridine, pyrimidine, piperidine, Morpholine, or quinoline. Pyridine is preferred, 2,4,6-trimethylpyridine, 4-dimethyla.minopyridine, 4-tridecylpyridine, Isobutylamine, iriethylamine, N-methylpiperidine, N-methylmorpholine, bis- (1,8) -dimethylaminonaphthalene, 1,4-diazabicyclo (2,2,2) octane and quinuclidine.

Lewis nitrogen bases are preferably used as promoters in an amount of about 0.02 to 2 equivalents, in particular 0.1 to 1 equivalent, per mole of rhodium in the Reaction mass on. The number of equivalents of promoter is equal to the number of moles of promoter multiplied by the number of nitrogen atoms in each molecule.

Mixtures of the above salts and amines as promoters for low working pressures can be used according to the invention. The promoters are involved in the reaction in the form of

used in the compounds or reactor substances

introduced which are able to form salt and / or amine as a catalyst in situ either before or during the implementation of the process according to the invention, such as an amide, for example formamide or urea, or an oxime which can be used as a promoter instead of an amine. Preferred promoters for low working pressures are trialkanolamine borates, especially those of the formula

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wherein R _& , R ^ and R _{0 can be} a hydrogen atom or a lower alkyl group with 1 to 12 G atoms in the chain. Triethanolamine borate and triisopropanolamine borate are particularly preferred.

The amount of catalyst is not critical and can vary over a wide range. Ma, n can use amounts as small as about 1 χ 10% by weight or less , based on rhodium metal, in the total weight of the reaction mass. The upper limit of the concentration can be quite high, e.g. 50 wt. Fo Rh and above. The actual upper limit to be applied depends primarily on the cost of rhodium metal and rhodium compounds from an economic point of view. Depending on various factors, such as the choice of promoter, partial pressures of hydrogen and carbon oxides, working pressure, working temperature, choice of the second solvent and other conditions, a catalyst concentration of about. 1 χ 10 to 5% by weight of Rh, contained in the complex, based on the total weight of the reaction mass, has proven to be expedient.

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A *

The reaction temperature can fluctuate within wide limits of elevated temperatures. In general, the process is carried out at about 100 to 375 ^° C. or even above. At lower temperatures, the reaction rate or conversion becomes noticeably slower at higher temperatures and above the specified temperature, catalyst instability can occur, but the reaction continues and alkane polyols and / or their derivatives are formed. The equilibrium reaction with the formation of ethylene glycol must also be taken into account

2 CO + 3H ₂ HIGH ₂ CH ₂ OH

At relatively high temperatures, the equilibrium is shifted more and more to the left. In order to shift the reaction to increasing amounts of ethylene glycol, higher partial pressures of carbon monoxide and hydrogen are required. A method in accordance with higher pressures are not preferred because of the high investment costs for the plant · Suitable temperatures are about 150 to 32O ⁰ C, in particular 210 to 300 ° C.

The residence time for the process according to the invention can be expected from a few minutes to several hours, e.g.

a few minutes to about 24 hours, the dwell time affects

the reaction temperature flows to a noticeable extent, the concentration and the choice of catalyst, the total gas pressure and the partial pressures, the concentration and the choice of the diluent, etc. The synthesis of the desired products by reacting hydrogen with carbon

7GT98

oxide is expediently carried out under working conditions that one corresponding reaction rates and / or Um-. Settlements received.

The relative amounts of carbon oxide and hydrogen in the reaction mixture at the beginning of the process can vary widely. In general, a molar ratio of C0 / H ₂ of about 20: 1 to 1:20 is used, 10: 1 Ms 1:10 is preferred, in particular 5: 1 to 1: 5.

In principle, other molar ratios can also be used. Substances and reaction mixtures which form carbon monoxide or hydrogen under the reaction conditions can also be used instead of the initial gas mixture CO + H ₂ . In this way, polyhydric alcohols are also obtained from mixtures containing CO ₂ and H ₂ . Mixtures of CQ ₂ , CO and H ₂ are also applicable; finally also a mixture of steam with CO.

The process according to the invention can be carried out batchwise or continuously or do it continuously. The conversion can take place in a single or in several reaction zones or in a tubular reactor. the The reaction zone can be provided with internal and / or external heat exchangers to avoid undue temperature fluctuations or even to prevent the exothermic reaction from running away. It is also preferred to stir. The catalyst can be introduced intermittently into the reaction zone e ± ris at the beginning or continuously or intermittently.

In the case of a continuous process, e.g. if it is preferred to work at relatively low degrees of conversion, it is generally desirable, unreacted synthesis gas, optionally with fresh carbon oxide and hydrogen to redirect. Obtaining the desired products can

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done in the usual way, such as by distillation, fractionation, extraction or the like. One the rhodium catalyst in by-products and / or the fraction containing normally liquid diluent one recirculate or wholly or partially for the work-up of the rhodium contents or for the regeneration of the Discharge active catalyst and from time to time into the reflux stream or directly into the reaction zone again to give up.

The active forms of the catalyst can be varied Way received. In this way, the catalyst can be preformed and then introduced into the reaction zone. But you can also rhodium-containing substances as well as promoters for lower Introduce working pressures into the reaction zone and under operating conditions including the presence of hydrogen and carbon monoxide, the active rhodium carbonyl cluster compounds form in situ. Examples of useful rhodium-containing starting substances are rhodium oxide (RhpO,), tetrarhodiumdodecacarbonyl, dirhodiumocta.carbonyl, Hexarhodiumhexadecaca.rbonyl (Rhg (CO) ^ g), Rhodium (II) format, acetate, propionate, butyrate, valerate, naphthenate, rhodium dicarbonylacetylacetona.t, rhodium tri (acetylacetonate), Rhoaium trihydroxide, indenyl rhodium dicarbonyl, rhodium dicarbonyl- (1-phenylbut.a.n-1,3-dione), tris (hexane-2,4-dionato) -rhodium (III), tris (Hepta.n-2,4-diona.to) rhodium (III), tris- (3-methylpenta.n-2,4-dionato) rhodium (III), tris (1-cyclohexylbutane-1,3-dionato) rhodium (III), Triacontacarbonylrhodium salts and compounds containing rhodium on porous supports, form the rhodium carbonyls in solution.

The rhodium carbonyl complex compounds are produced expediently in the solvent mixture. Because of its limited solubility, tetrarhodium

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Add finely divided dodecacarbonyl to the solvent. The above rhodium compounds can be used instead of tetrarhodium dodecacarbonyl. Organic Lewis bases such as pyridine and other promoters such as the above salts can be added. The complex-forming reaction can take place under carbon monoxide pressure (optionally with hydrogen) of about 1 to 15 atmospheres or above and at temperatures between about 30 and 100 ^° C. in a few minutes to a few days, generally from about. 30 minutes to 24 hours. The complex in the solvent mixture is catalytically active for the process according to the invention. In the preparation of the above complexes, about 0.01 to 25 moles of salt or Lewis nitrogen base can be used as promoters per mole of rhodium. Other ratios are useful, especially when dilution amounts of the promoters are used for low pressure.

A device and the measure for determining the presence of anionic rhodium carbonyl complexes or clusters with a well-defined infrared spectrum during the reaction according to the method according to the invention are older in the above Registration described. A particularly suitable infrared cell is one according to US Pat. No. 3,886,364.

In addition to carbon monoxide, “carbon oxide ^1” is understood here to mean a mixture of carbon dioxide and carbon monoxide, such as is either introduced directly into the reaction or in which it is formed. However, preference is given to using carbon monoxide.

The invention is further illustrated by the following examples .

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- g-r-

To analyze the reactor contents on the rhodium

-z.

The reactor was rinsed with 100 cnr solvent, the contents brought to 160 ° C and a pressure of 984 to 1054 and left there for 30 minutes, then cooled, unreacted gas vented off and the rhodium content determined again. The rhodium values are in the following tables in %, based on total rhodium used, indicated as dissolved or suspended rhodium used and proportion in the washing liquid. The substances used in the examples had the following characteristics:

Cesium benzoate, recrystallized from water, analysis - found: 32.62 % C and 1.9 % H, calculated on C ₇ H ₅ O ₂ Cs: 33.1 % C and 1.98 % H; Triisopropanolamine borate m.p. 155-157 ° C; P-MeSO ₂ CgH ₄ CO ₂ Cs Cesium p-methylsulfonyl benzoate recrystallized from H ₂ O. Analysis: found 28.26 % C, 2.05 % H calculated on
C ₈ H ₇ O ₄ SCs: 28.9% C, 2.13 % H.

A premix of 75 cm of solvent mixture, a certain amount of rhodium dicarbonylacetylacetonate and certain proportions of amine, borate and salt as promoters were introduced into a 150 cm reactor made of corrosion-resistant steel for a maximum pressure of 7000 atü, the reactor was closed and an equimolar gas mixture of CO and H ₂ pressed in. As soon as the temperature

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door had reached 19O ⁰ C, the working pressure was adjusted to 562 atm and temperature and pressures maintained in accordance with the following table.

After completion of the reaction, the mixture was cooled to room temperature, Blow off excess pressure and discharge the reaction product. Analysis of the reaction products was carried out by gas chromatography. The yield of ethylene glycol and methanol as well as the recovery of the Rhodiums are summarized in the table.

Examples

The following examples show that a mixture of SuIfolan and tetraglyme leads to higher conversion than a pure solvent (Example. 1 to 27, 32 and 33). Also see one that the reaction according to the invention is better than with any pure solvent (Examples 1-15). In the end they show the increase in the amount of sulfolane required for good rhodium recovery with increasing temperature (Examples 12 to 15 versus 1 to 11, 26 and 27 versus 28, 29 and 30 ″, 31 and Examples 32, 33 versus 34, 35 and 36 to 38). This list also shows the need for higher pressures for good recovery of rhodium with increasing temperature at constant solvent ratio (Examples 1 to 15 and 18 to 20 compared to 34 to 40 and 28 to 31).

The rhodium recovery and thus the conversion to ^- glycol is determined by the 3-fold effect of solvent ratio, pressure and temperature. In order for the rhodium to remain in solution with increasing temperature and for glycol to be formed at a higher rate, it is necessary that the solvent ratio increase or decrease. This is a more imperative for lower pressures. With increasing temperature or decreasing pressure one reaches

709813/1040 - 23 -

a point where "e" is simply changed by changing the Solvent ratio no high recovery of rhodium can be achieved.

Tabel;

- 24 -

709813/1040

T a at 1 e:

• Ρ ¹ «
O

Ratio example sulfolane / pressure

Tetraglym e (psi) kg / cm xemp. ⁰ C MoI Rh

1 2 3 4 5 6

10 11

12 13 14 15

16 17

18 19 20

21 22 23 moles of promoter

100/0 (8000) 562 240 76/24 Il Il 240 54/46 Il Il 240 36/64 η Il 240 17/83 Il Il 240 0/100 Il 240 100/0 Il Il Il 76/24 It It Il 54/46 Il Il η 36/64 Il It Il 17/83 Il It Il 100/0 η It 260 76/24 Il Il Il 50/50 It Il dd 24/76 ti Il It 100/0 Il It 240 76/24 Il Il 240 100/0 ti Il 260 76/24 η η 260 50/50 Il It 260 50/50 (15000) 1054 240 13/87 Il Il 240 0/100 Il Il 240

η tt ti η

η ti it

Cs-benzoate it it η II Il

Pyridine

Il Il Il

0.65

Il It Il It Il

0.63

Il Il Il Il

Ethylene dimorpholine 7.0

Π Il

N-methylmorpholine

Cs formate Il Il

Cs benzoate

It It

0.65 0.65 0.65

0.65 0.65

0.65

It
Il t 2 C.
Il 5.0
Il f dd Triisoproparolamine borate
Il ti Il Il It Il

to Ui

Continuation table

Ex. Relation pressure Il 1054
It Temp. C Mole Rh Mol Promotoi 7.0
Il Il 1.25
1.25 Sulfolane / Il Il
π 260
260 3
3 Ethylene dimorpholine
ti Cs benzoate 0.75 pyridine
η 0.375 " Il ti 24
25th Tetraglyme Il η 260
260 3
1.5 Il Il Il Il 26th
27 100/0 I.
50/50 (psi) kg / cnT It Il 270 1.5 Il Il Il Il 28 24/76
0/100 (15000)
Il Il Il 270 1.5 η ti ti Il 29 50/50 Il
Il Il It 280 1.5 η Ii It 2.5 30th 24/76 Il It 879 280 1.5 »1.5 It 2.5 31 50/50 Il Il 250 6th "1.5 Il 1.25 32 24/76 Il η η 250 6th ¹¹ 0.75 Il 1.25 ο
co 33 Il Il 260 3 "0.75 It 1.25 00 34 0/100 (12500) Il 260 3 ⁿ 0.375 Il 1.25 co 35 24/76 η 270 1.5 »0.375 0.75 1.25 -> ■ *. 36 24/76 It 270 1.5 ^π 0.375 2.5 O 37 50/50 η 270 1.5 Cs-p-methyl sulfonyl benzoate 0.75 4> 38 24/76 270 3 Triisoproparolamine borate 2.5 O 39 50/50 It Cs-p-methyl sulfonyl benzoate 60/40 ■ 270 3 Triisoproparolamine borate ro 40 24/76 CD CO 50/50 CD

Tabel :

example Methanol Ethylene Recovery To wash Gas intake _k psi;
r> 197 reaction time H \ Mol / h (g) glycol mol / h (g) % Rh 6th (C0 + H ₂ ) ( C. 228 4.0 1 0.31 (3.0) . 0.23 (4.2) reactor 10 kg / or 207 4.0 2 0.29 (2.8) 0.22 (4.0) 74 11 (2800) '200 4.0 3 0.31 (3.0) 0.28 (5.2) 74 20th (3250) 221 4.0 4th 0.34 (3.3) 0.26 (4.9) 74 21 (2950) 148 4.0 • 5 0.36 (3.5) 0.26 (4.9) 68 52 (2850) 211 4.0 6th 0.23 (2.2) 0.16 (2.9) 62 6th (3150) 264 π 7th 0.29 (2.8) 0.24 (4.5) 27 6th (2100) 246 η ■ »■ J
CD 8th 0.27 (2.6) 0.35 (6.5) 77 10 (3000) 200 η CO 9 0.28 (2.7) 0.29 (5.3) 71 5 (3750) 119 It ro
CD OO 10 0.27 (2.6) 0.28 (5.2) 62 0 (3500) 394 Il -! >> co 11 0.27 (2.6) ■ 0.13 (2.4) 54 6th (2850) 457 ti CO
CO 12th 0.54 (5.2) 0.38 (7.1) 33 7th (1700) 422 Il O 13th 0.57 (5.5) 0.38 (7.1) 81 8th (5600) 144 η ⁴ ^. 14th 0.62 (6.0) 0.41 (7.7) 68 4th (6500) 302 π 15th 0.25 (2.4) 0.06 (1.1) 67 4th (6000) 295 Il 16 0.37 (3.6) 0.29 (5.3) 11 8th (2050) 288 π 17th 0.32 (3.1) 0.31 (5.7) 80 10 (4300) 323 Il 18th 0.47 (4.5) 0.32 (6.0) 74 6th (4200) 394 η 19th 0.57 (5.5) 0.35 (6.5) 77 12th (4100) 439 Il 20th 0.60 (5.8) 0.39 (7.2) 77 6th (4600) 576 0.65 21 1st, 1 (1.7) 2.1 (6.3) 53 5 (5600) 429 1.25 22nd 1.6 (4.7) 2.0 (11.7) 102 8th (6250) 0.96 23 1.6 (3.6) 1.4 (6.2) 82 (8200) I.
ro 69 (6100)

Table continued example

Methanol mol / h (g)

Ethylene glycol mol / h Cg)

Recovery

% Rh reactor washing

Gas uptake (C0 + H ₂ ) (psil kg / cnr

Response time h

24 25

26 27

28 29

30 31

32 33

34 35

36 37 38

39 40

3.1 (4.1) 2.7 (5.4)

3.1 (3.7) 1.7 (3.7)

2.7 (4.3) 2.9 (2.5)

4.3 (5.9)

3.2 (5.8)

3.1 (6.5)

5.8 (8.0)

3.0 (5 _t 7)

2.9 (5.5)

0.35 (3.5) 1.7 (3.8) 2.0 (4.0)

2.4 (6.3) 2.0 (5.5)

2.9 (7.4) 3.7 (14.2)

4.9 (11.4)

2.0 (8.4)

3.2 (10.6)

4.1 (6.9)

4.4 (11.8) 2.7 (9.4)

2.4 (9.8) 3.4 (9.2)

2.6 (9.9)

2.7 (9.8)

0.25 (5.3) 1.7 (7.3) 1.7 (6.8)

1.9 (9.8) 1.7 (8.9)

107

83 70

80 76

76 39

78 85

92 98

19 81 78 '

29 44

6 6

6 14

6 7

16 25

11 6

5 6

36 13 17

41 16

(6000) 422

(7300) 513

(7800) 548

(6000) 422

(6000) 422

(4050) 285

(6400) 450

(6000) 422

(6000) 422

(6150) 432

(6000) 422

(6000) 422

(Λ000) 281

(4000) 281

(4000) 281

(6000) 422

(6000) 422

0.55 0.83

1.00 0.45

0.67 0.36

0.58 0.76

0.88 0.58

0.80 0.77

4.18 0.95 0.85

1.08 1.16

ro

CD

co

CD

Claims (1)

Claim .Enoxiden process for producing alkane polyols by reacting Koh and a rhodium complex catalyst in a homogeneous liquid phase at about 100 hydrogen in the presence - 375 ⁰ C and a pressure of about 70 - ata 3515, characterized in that the reaction in a solvent mixture of Carries out tetraglyme and sulfolane, the solvent ratio being chosen such that the formation of alkane polyol is greater than under similar conditions using only one solvent. 8183 709813/1040