SE444932B - PROCEDURE FOR RODIUM-CATALYZED HYDROFORMATION OF OLEFINES FOR THE PREPARATION OF SIMILAR ALDEHYDES - Google Patents

Description

7800871-1 2 (2) A drolefin starting material of arolefinic compounds characterized by a terminal ethylene carbon-to-carbon bond, for example a vinyl group CH2 = CH-. These may be straight-chain or branched-chain and may contain groups or substituents which do not substantially interfere with the hydroformylation reaction and may also contain more than one ethylene bond. Propylene is an example of a preferred 2-olefin. (3) A triorganophosphorus ligand, for example a triarylphosphine.

It is convenient that each organo group in the ligand does not exceed 18 carbon atoms. The triarylphosphines are preferred ligands and an example is triphenylphosphine. (4) A concentration of the triorganophosphorus ligand in the reaction mixture which is sufficient to give at least 2 and preferably at least 5 moles of free ligand per mole of rhodium metal in addition to the ligand which is complexed with or bound to the rhodium atom. (5) A temperature of from about 50 to about 145 ° C, preferably from about 50 ° to about 12 ° C. (6) - A total pressure of hydrogen and carbon monoxide lower than 32 ata and preferably less than 25 ata.a (7) A maximum partial pressure of carbon monoxide not exceeding about 75% based on the total pressure of carbon monoxide and hydrogen and preferably is lower than 50% of this total gas pressure.

It is known that a certain portion of the product aldehydes under the hydroformylation conditions can be condensed to form by-products, high boiling aldehyde condensation products, for example aldehyde dimers or trimers. U.S. Patent No. 4,148,830 discloses the use of these high boiling liquid aldehyde condensation products as reaction catalysts for the catalyst. In this process is the removal of solvent from the catalyst. which could cause catalyst losses. not necessary and in the process a liquid containing the solvent in the form of high boiling aldehyde condensation products and catalyst is fed to the reaction zone from a product recovery zone. It may be necessary to remove a small purge stream to prevent the accumulation of such aldehyde acondylation components. -for high levels.

As disclosed in U.S. Patent No. 4,148,830, a certain portion of the aldehyde product in various reactions, as set forth in 7800871-1 the following using n-butyraldehyde as an example: on -H o _:> cn3cH -cnscszcnzca = ïcæo, CH0 I c fl a - caz alaol (1) fl1 ö0l (I) substituted acrolein (II) 2CH3CH2CH2CHC CH3CH2CH2CHO OIA OH occxzcsz CHZCHCHCHZCHB csšcs cazça222 cC cn cCnC trime: III) (trimer IV) heat OH CH3CH2CH2CO0 CH3CH2CH2CHCECH2CH3 CH3CH2CEåCHCHCH2CH3 cazo fi QH cH2occ¿2cs2cH3 (dimer V) (tetramer VI) In addition, aldol I may undergo the following reaction: 7800871-1 IH _> 2 al3 ¿Scacs2cx3 OH COOCH2? HCHCH2CH2CH3 CHZCHB (tetramer VII) The names in parentheses i'de in the above equations, aldol I, substituted acrolein II, trimer III, trimer IV, dimer V, tetramer VI and tetramer VII, are given only such as simplification. Aldol I is formed by an aldon condensation, trimer III and tetramer VII are formed via Tischenko reactions, trimer IV by a transesterification reaction, dimer V and tetramer VI by a dismutation reaction. The main condensation products are trimer III, trimer IV and tetramer VII with minor amounts of the other products present. Such condensation products therefore contain significant levels of hydroxyl compounds, as exemplified e.g. with trimers III and IV and tetramers VII. Similar condensation products are formed by self-condensation of iso-butyraldehyde and a further range of compounds are formed by condensation of a molecule of normal butyraldehyde with a molecule of iso-butyraldehyde. Since a molecule of normal butyraldehyde can aldolisate by reaction with a molecule of isobutyraldehyde in two different ways to form two different aldols VIII and IX, a total of four aldols can be formed by condensation reactions of a mixture of normal / iso-butyraldehydes.

OH CE3 CH CH CH CEO + CHBCHCE3 - §> CH3CH2CH2CH-CCH3 3 2 2 CHO C30 Alåol (VIII) cH3d H cn-cnc fl cnzqns CH3 cxo Alaoluilx) 7800871-1 Aldol I may undergo further condensation with isobutyraldehyde to form a trimer, which is isomer with trimer III, and aldols VIII and IX and the corresponding aldol X formed by self-condensation of two molecules of isobutyraldehyde, may undergo further reactions with either normal or isobutyraldehyde to form the corresponding isomeric trimers. These trimers can react further analogously with trimer III, so that a complex mixture of condensation products is formed.

U.S. Patent No. 4,247,486 discloses a liquid phase hydroformylation reaction using a rhodium complex catalyst, in which the aldehyde reaction products and some of their high-boiling condensation products are removed in vapor form from the catalyst-containing liquid quantity (or solution) at the reaction temperature and reaction temperature. The aldehyde reaction products and condensation products are condensed out of the exhaust gas from the reaction vessel in a product recovery zone and the unreacted starting materials (eg carbon monoxide, hydrogen and / or α-olefin) in the vapor phase from the product recovery zone are recycled to the reaction zone. By recycling gas from the product recovery zone together with or coupled with supplementary feedstock to the reaction zone in sufficient quantities, it is possible, using a C2 to CS olefin as the olefin feedstock, to achieve a mass balance in the liquid quantity in the reactor and that thereby removing substantially all of the higher boiling condensation products resulting from self-condensation of the aldehyde product from the reaction zone at a rate at least equal to the rate of formation.

The aforementioned U.S. patent application discloses a process for producing an aldehyde containing from 3 to 6 carbon atoms, wherein an α-olefin containing from 2 to 5 carbon atoms is combined with hydrogen and carbon monoxide at a predetermined temperature and a predetermined pressure by a reaction zone containing the rhodium complex catalyst dissolved in a liquid quantity and continuously removing a vapor phase from the reaction zone, for the vapor phase to a product separation zone, separating a liquid aldehyde-containing product in the product separation zone by condensation from the gaseous unreacted starting materials. from the product separation zone to the reaction zone. It is convenient that the gaseous unreacted starting materials plus complementary starting materials be recycled in an amount at least equal to that required to maintain a mass balance in the reaction zone.

It is previously known that rhodium hydroformylation catalysts, for example hydridocarbonyltris (triphenylphosphine) rhodium, are deactivated by certain external toxins, which may be present in any of the gases fed to the reaction mixture. See, for example, G. Falbe, "Carbon Monoxide in Organic Synthesis", Springer-Verlag, New York, 1970. These toxins (X), called virulent toxins, are derived from such materials as sulfur-containing compounds (e.g. Hzs, COS, etc. ), halogen-containing compounds (e.g. HCl, etc.), cyano-containing compounds, e.g. HCN, etc.) and the like and can form Rh-X bonds which do not break under mild hydroformylation conditions. If such toxins are removed from the materials fed to the reaction zone to a level below 1 ppm, it would be expected that no such deactivation of the catalyst would occur. However, it has been shown that this is not the case. For example, if very pure gases (<1 ppm external toxins) were used in the hydroformylation of propylene and the previously discussed recycle of gas was used, under the following conditions: temperature (° c) loop CO partial pressure (ata) 2.53 H2 partial pressure (ata) 5.27 olefin partial pressure (ata) 2.81 ligand / rhodium molar ratio 94 decreases the activity of the catalyst at a rate of 3% per day (based on the initial activity of the fresh catalyst). It is therefore apparent that even substantially complete sap removal of external toxins does not prevent such deactivation of the catalyst. U.S. Patent No. 4,277,627 states that the deactivation of the rhodium hydroformylation catalysts under the hydroformylation conditions in the substantial absence of external toxins is due to the combination of effects of temperature, phosphine ligand-rhodium molar ratio and partial pressures of hydrogen and carbon monoxide. internal deactivation. It is further stated that this internal deactivation can be reduced or substantially prevented by providing and regulating and correlating the hydroformylation reaction conditions to a low temperature, low carbon monoxide partial pressure and high molar ratio of free triarylphosphine ligand: catalytically active rhodium. In particular, this patent application discloses a rhodium catalyzed hydroformylation process for the preparation of aldehydes of G-olefins comprising as a step reaction of the olefin with hydrogen and carbon monoxide in the presence of rhodium complex catalysts consisting essentially of rhodium complexed with carbon monoxide and triarylphose defined reaction conditions, as follows: (1) A temperature of from about 90 to about 130 ° C, 7 (2) a total gas pressure of hydrogen, carbon monoxide and d-olefin of less than about 28 ata, (3) a carbon monoxide partial pressure of less than about 3.9 ata, (4) a hydrogen partial pressure of less than about 14 ata, e (5) at least about 100 moles of free triarylphosphine ligand per each mole of catalytically active rhodium metal present in the rhodium complex catalyst, and regulation and correlation of the partial pressure of carbon monoxide, the temperature and the molar ratio of free triarylphosphine: catalytically active rhodium to limit the deactivation of the rhodium complex catalyst to a maximum determined percentage loss expressed as activity per day, based on the initial activity of the fresh catalyst. By "catalytically active rhodium" is meant rhodium metal in the rhodium complex catalyst which has not been deactivated.

The amount of rhodium in the reaction zone that is catalytically active can be determined at any given time during the reaction by comparing the rate of conversion to product based on this catalyst compared to the rate of conversion obtained using fresh catalyst. The manner in which the carbon monoxide partial pressure, temperature and molar ratio of free triarylphosphine catalytically active rhodium are to be controlled and correlated to limit the deactivation of the catalyst is illustrated in the following manner.

As an example using the triarylphosphine ligand triphenylphosphine, the specific relationship between these three parameters and the stability of the catalyst is defined by the formula: 'F = looo 1 + ey in which 7 F = stability factor _ e = natural logarithm base (ie 2.7l828l828) y = K1 + KZT + K3P + K4 (L / Rh) T = reaction temperature (OC) -P = partial pressure of CO (at) L / Rh = molar ratio free triarylphosphine: catalytically active rhodium K1 = -8,116 K2 = 0.079l9 K3 - 0.397 K4 = -0.01555 As pointed out in the aforementioned patent application (inventors Bryant and Billig), an olefin response factor must be used to obtain the stability factor under real hydroformylation conditions. Olefins generally improve the stability of the catalyst and their effect on the stability of the catalyst is explained in more detail in the above-mentioned patent application.

The above relationship is essentially the same for other triarylphosphines, except that the constants K1, F1, K3 and K4 may be different. Those skilled in the art can determine the specific constants for other triarylphosphines with a minimal amount of experimentation, for example, by repeating Examples 21-30 below with other triarylphosphines. As can be seen from the above formula, the stability factor F can be determined for given conditions regarding reaction temperature, carbon monoxide partial pressure and molar ratio of free triarylphosphine catalytically active rhodium. The stability factor F shows a predeterminable relationship with the rate at which the rhodium complex catalyst is deactivated under the hydroformylation conditions. This relationship is illustrated by Figure 1, which shows the variation in the stability factor F for different rates of catalyst activity losses for the triarylphosphine triphenylphosphine. This drawing shows that the rate of activity loss decreases substantially linearly with increasing value of the stability factor F. The determination of the maximum allowable rate of loss of activity of the catalyst must finally be largely based on the economic conditions of the process, including predominantly the cost of replacing consumed or deactivated catalyst and also the value of the products, etc. For purposes of discussion, assuming that the maximum acceptable rate of activity loss of the catalyst is 0.75% per day, it can be deduced from Figure 1 that the corresponding minimum value of the stability factor F is about 770. can be used to determine the reaction conditions which give this The above equation can require the minimum value of the stability factor F and as a result this maximum acceptable velocity loss for the catalyst activity. Since the above equation has three variables, it can be more easily understood with reference to Figures 2, 43 and 4, which show the effect on the stability factor F of variations of two of these three variables, the third being kept constant. Figures 2, 3 and 4 show the effect of these three variables on the stability factor F for the olefin propylene and to simplify the description, the following discussion is limited to the principle as olefin. However, a similar relationship exists for other olefins and could be illustrated in the same manner as shown in Figures 2, 3 and 4.

The values given in Figure 2 were obtained by calculating the stability factor F when hydroformylating propylene with a constant molar ratio of free triarylphosphine: catalytically active rhodium of 170: 1 (the triarylphosphine in question consisted of triphenylphosphine) and at varying temperatures and partial pressures of carbon monoxide. Lines A, B and C denote the areas where the stability factor F is about 500, 800 and 900. at most at low partial pressure of carbon monoxide and low temperature at a certain determined molar ratio of free triarylphosphine: catalytically active rhodium.

Figure 2 shows that the stability factor F is Figure 3 shows the relationship between the stability factor F and 7800871-1 varying temperatures and molar ratios of free triarylphosphine: catalytically active rhodium (triarylphosphine = triphenylphosphine) with a constant partial pressure of carbon monoxide of 1,75 ata for hydroformyl. ring of propylene. Lines A, B and C indicate the areas along which the stability factor F is about 500, 800 and 900. As shown in Figure 3, the stability factor F is highest at low temperatures and high molar ratios of free triarylphosphine: catalytically active rhodium, at a certain partial pressure of carbon monoxide.

Figure 4 shows the relationship between the stability factor F and Varying partial pressure of carbon monoxide and the molar ratio of free triarylphosphine: catalytically active rhodium (triarylphosphine = triphenylphosphinel at constant reaction temperature 110C at hydroformylerin: of propylene. Lines A, B and C denote the regions along which about 500, 800 and 900, respectively. As shown in Figure 4, the stability factor F is highest at high molar ratio of free triarylphosphine: catalytically active rhodium and at low partial pressure of carbon monoxide at a certain determined temperature.

Figures 2, 3 and 4 are only intended to be representative of the invention. For example, if a different determined temperature were used in the relationship illustrated in Figure 4, the values given for the stability factor F would have been different.

The same applies to Figures 2 and 3 about other selected values of the molar ratio free triarylphosphine: catalytically active rhodium resp. partial pressure of carbon monoxide selected. Thus, each of Figures 2, 3 and 4 indicates a simple plane in the three-dimensional relationship that exists between the stability factor F and the condition temperature, carbon monoxide partial pressure and molar ratio of free triaryl phosphine: catalytically active rhodium, the plane of course being the same as the plane in the three-dimensional figure that intersects the selected value of the constant variable in each particular case.

These two-dimensional representations are intended only to illustrate the invention.

The conditions regarding temperature, partial pressure of carbon monoxide and molar ratio of free triarylphosphine: catalytically active rhodium, which are controlled and correlated to obtain minimal catalyst deactivation, are thus determined as follows. The determined threshold values constitute a maximum acceptable rate of catalyst activity loss. With this value and using 7800871s1 ll for example of the relationship shown in figure 1, the minimum stability factor F can be determined. The above equation is then solved to determine the values of the three variables, which are adjusted to obtain this minimum value of the stability factor F, and in this context figures, such as Figures 2, 3 and 4, are helpful in determining specific conditions. which gives stable catalyst.

It is generally desirable that the maximum loss of activity of the rhodium complex catalyst be 0.75% per day and very advantageous results have been obtained if the maximum rate of loss of catalyst activity is 0.3% per day, both of these values being based on the activity of the fresh catalyst. By the term "activity" is meant, for example, the amount of product produced expressed in grams mol / liter.hour. Of course, any other standard method can be used to determine the relative activity of the catalyst at any given time. It should be noted, however, that the maximum acceptable rate of loss for catalyst activity depends on many different factors as pointed out above. The method disclosed in the above-mentioned patent application, inventors Bryant and Billig, offers a mechanism for obtaining an arbitrary maximum rate for the loss of catalyst activity by regulating and correlating the conditions of the hydroformylation reaction. Stated otherwise, once a maximum acceptable rate of catalyst activity loss has been determined, the invention disclosed in the above-mentioned patent application offers those skilled in the art a tool for regulating and correlating the reaction conditions in a manner necessary to obtain catalyst stability. The values given above for the maximum rate of catalyst activity loss are thus given only to show the person skilled in the art how the invention is to be applied.

As noted above, the presence of the olefin in the hydroformylation reaction improves the stability of the catalyst, i.e. inhibits the deactivation caused by the combination of carbon monoxide, hydrogen, the phosphine ligand: rhodium molar ratio and temperature. One can determine the effect of the olefin on the calculation of the stability factor. For example, in hydroformylation of propylene, reaction conditions which offer long-term catalyst stability (ie, a low rate of catalyst activity loss) give a stability factor F, determined from Figure 1, with the observed rate of loss of catalyst activity; of about 850.

However, by using these conditions and the above formulas, a stability factor F of about 870 can be calculated. It is only necessary to make the necessary modification of the above equation to include the effect of propylene on the stability factor. Similar data can be readily obtained for olefinic olefins and the necessary modifications can be made to the above formula to determine the actual reaction conditions to be used to obtain long-term lysator stability. It has been found that the presence of an alkyldiarylphosphine (for example propyldiphenylphosphine or ethyldiphenylphosphine) in the rhodium-catalyzed hydroformylation of the Q-olefin propylene inhibits the productivity of the catalyst, i.e. the rate at which the desired product aldehydes are formed. In particular, the addition of small amounts of propyldiphenylphosphine or ethyldiphenylphosphine to rhodium hydroformylation solutions (ie 250 ppm rhodium and 12% by weight of triphenylphosphine in a mixture of butyraldehydes and butyraldehyde condensation products) significantly reduces the rate of formation of propylene which achieved in the absence of the alkyldiarylphosphines.

This is shown by the values in Table I. 78ÛU871 ~ 1 13 PDPP (2) Table I.

TPP (l) Éàš: ï3) 1 :: g: l_ Aldehyde production- Relative (weightpr0- (weightpr0- PDPP speed formation) Percent of cents of or (gram mol / liter-hour) rapid-search solution) solution) EDPP / TPP Observed Calculated (4) hot (51 l 4 PDPP (O) 0 1.03 1, O2 100 2 1.89 "(2.0) 1.05 0.36 _ 1.06 34 3 3.74 "(0.67) 0.18 0.53 1.02 53 4 4.06" (1.33) 0.33 0.79 1.87 42 3.61 "(1.33) 0.37 1, 51 3.51 43 6 4.0 "(0.05) 0.013 0.62 1.02 60 7 9" (1.0) 0.11 0.60 0.69 87 8 6 "(1.0) 0 , 17 0.54 0.63 86 9 9 "(3.0) 0.33 0.54 0.72 75" 6 "(3.0), 0.5_ 0.47 0 0.68 68 11 79" (1.0) 0.11 0.55 0.69 so 12 6 "(1.0) 0.17 0.58 0.63 92 13 9" (3.0) 0.33 0.39 0.72 54 14 6 "(3.0) 0.5 0.52 0.66 77 higher than 9" (O) O 0.80 0.60 100 16 O "(9) - 0.273 0.60 46 17 _0" ( 4.5) ~ 0.213 0.47 45 18 3.89 EDPP (0.67) 0.17 0.42 1.02 42 19 3.69 "(0.67) 0.18 0.42 1.02 42 3.88 "(1.33) 0.34 0.33 1.02 33 21 _ 6.95" (0.67) 0.10 0.32 0.82 39 22 6.85 "(1.33) 0.19 0.24 '0.82 29 (1) TPP = triphenylphosphine (2) PDPP = propyldiphenylphosphine (3) EDPP = ethyldif enylphosphine (4) Predicted rate determined by an expression of kinetic rate (5) Relative rate of formation = observed rate x 100 predetermined rate for the same conditions with the same total amount of phosphine alone as TPP 7800871-1 It has therefore been suggested that the presence of alkyldiarylphosphines Rhodium-catalyzed hydroformylation processes should be avoided, as the presence of these substances significantly reduces the productivity of the catalyst. However, it has been quite surprisingly found that the stability of such rhodium complex catalysts can be significantly improved by providing an alkyldiarylphosphine in the reaction medium. Although this reduces the productivity of the catalyst, the reaction conditions can be adjusted to become more demanding, so as to recover this apparent loss of catalyst productivity while maintaining the improved catalyst stability. This is surprising especially in view of the information in the aforementioned patent application of Éryant and Billig, according to which less demanding conditions (for example lower temperature) favor the stability of the catalyst.

The present invention includes an improved rhodium-catalyzed hydroformylation process for the preparation of aldehydes of afolefins using a rhodium complex catalyst, wherein the stability of the rhodium complex catalyst is improved by providing a certain amount of alkyldiarylphosphine ligand in the catalyst-containing reaction medium. Thus, the stability of the rhodium complex catalyst can be substantially improved.

In a broadest aspect, the present invention is an improvement on a rhodium catalyzed process for the hydroformylation of a d-olefin containing 2-20 carbon atoms to produce aldehydes containing one carbon atom more than the d-olefin by reacting the d-olefin with hydrogen and carbon monoxide in a liquid reaction medium containing a soluble rhodium complex catalyst consisting essentially of rhodium complexed with carbon monoxide and a triarylphosphine ligand, and in the presence of free triarylphosphine which process is characterized by improving the stability of the catalyst by maintaining the liquid contained in the liquid. about 0.1 to 20% by weight of an alkyl diarylphosphine ligand based on the total weight of the liquid reaction medium, and regulating the reaction conditions to a temperature of from about 100 ° to about 140 ° C, a total gas pressure of hydrogen, carbon monoxide and acolefin lower. than about 31.5 ata, 'a carbon monoxide oxide partial pressure below about 3.85 ata, a hydrogen partial pressure below about 14 ata, and at least about 75 moles of total free phosphine ligand per mole of catalytically active rhodium metal present in the rhodium complex catalyst consisting essentially of rhodium complexed with carbon monoxide and a or both of said triarylphosphine and said alkyldiarylphosphine.

In general, the amount of the alkyldiarylphosphine ligand present in the liquid reaction medium is from about 0.1 to about 20% by weight, based on the total weight of the liquid reaction medium. If a triarylphosphine ligand is used in the hydroformylation of a β-olefin, a certain amount of alkyldirylphosphine is formed in situ, the "alkyl" group thereof being derived from the G-olefin undergoing hydroformylation and the "aryl" groups being the same as the arylene of the triarylphosphine It may therefore be unnecessary to add additional alkyldiarylphosphine to the reaction medium to provide a sufficient amount of it in the reaction medium.

The particular amount of alkyldiarylphosphine in the reaction medium depends on a number of factors, for example, the particular G-olefin reacted, the reaction conditions, the desired reaction rate, etc. In general, however, amounts falling within the aforementioned range give satisfactory results. . Particularly advantageous results are obtained if the amount of alkyl diaryl phosphine in the liquid reaction medium is from about 0.5 to about 10% by weight, based on the total weight of the liquid reaction medium, and therefore this is a preferred embodiment.

When an alkyldiarylphosphine ligand is present in a liquid reaction medium containing a rhodium complex catalyst consisting essentially of rhodium complexed with carbon monoxide and a triarylphosphine ligand, the rhodium complex catalyst obtained consists essentially of rhodium complexed with carbon monoxide or triphylline or either an alphosphine ligand.

The term "consists essentially of" also includes hydrogen which is complexed with rhodium, in addition to carbon monoxide and triarylphosphine and / or alkyldiarylphosphine. However, this term excludes other materials in amounts that poison or deactivate the catalyst. Furthermore, it is not intended to limit the present invention by the foregoing explanation of phosphine bound to or complexed with rhodium, since for the purpose of the invention it is sufficient to add an amount of alkyldiarylphosphine to the reaction medium. The invention is not limited to any discussion of which phosphine is bound to rhodium and which is free, although it has been found that, with respect to triphenylphosphine and propyldiphenylphosphine, rhodium has a preference for the latter substance. in relation to the former regarding binding. This catalyst is normally soluble in the liquids which can be used as solvents in the reaction and the most desirable catalyst is free from impurities such as rhodium-bonded halogen, chlorine and similar substances. The total amount of triarylphosphine and alkyldiarylphosphine present in the liquid reaction medium is sufficient to give the above minimum number of moles of free phosphine ligand per mole of catalytically active rhodium metal present in the rhodium complex catalyst. In general, as long as the total number of phosphine ligands is sufficient to form the rhodium complex catalyst and to provide this minimum amount of free phosphine, the particular amount of trialkylphosphine ligand present in the liquid reaction medium is not particularly critical; As a general rule, the amount of triarylphosphine ligand present in the reaction medium can vary from about 0.5% to about 40%, based on the weight of the total liquid reaction medium. Particularly advantageous results are obtained if the amount of total free phosphine ligand in the liquid reaction medium is at least about 100 moles per mole of catalytically active rhodium metal present in the rhodium complex catalyst. The upper limit of the amount of total free phosphine ligand is not particularly critical and is largely determined by commercial and economic considerations.

Higher molar ratios of total amount of free phosphine-catalytically active rhodium metal favor the stability of the catalyst. By "total amount of free phosphine" is meant the triarylphosphine and / or alkyldiarylphosphine which is not bound to or complexed with the rhodium atom of the active complex catalyst. The theory of complex binding of such ligands to rhodium is disclosed in U.S. Pat. No. 3,7,709. Examples of triarylphosphine ligands are triphenylphosphine, trianaphthylphosphine, tritolylphosphine, tri (p-biphenyl) -phosphine, tri (p-methoxyphenyl) -phosphine , pN, N-dimethylaminophenylbis-phenylphosphine and the like. 7800871-1 17 Triphenylphosphine is a preferred triarylphosphine ligand.

Examples of alkyldiarylphosphine ligands are methyldiphenylphosphine, ethyldiphenylphosphine, propyldiphenylphosphine, butyldiphenylphosphine, ethyl -bis (p-methoxyphenyl) -phosphine, ethyl-phenyl-p-biphenylphosphine, methyl--phenyl-p- (N, propyl-phenyl-β- (N, N--dimethylaminophenyl) -phosphine, ethyl-bis (tolyl) -phosphine, butyl-bis (thlyla--phosphine, methyl-bis (naphthyl) -phosphine, propyl-bis (naphthyl) -phosphine, propyl-bis (p-methoxyphenyl) -phosphine, butyl-bis (p-methoxyphenyl) -phosphine, etc. Propyldiphenylphosphine is the currently preferred alkyldiarylphosphine ligand.

The rhodium complex catalyst, which consists of rhodium complexed with hydrogen, carbon monoxide and triarylphosphine, can be prepared by methods known per se. Thus, for example, a preformed stable, crystalline solid of rhodium hydridocarbonyl-tris- (triphenylphosphine), RhH (CO) [η (C6H5) 3]] can be introduced into the reaction medium.

This material can be prepared, for example, by the method set forth by Brown et al., Journal of the Chemical Society, 1970, p. 2753-2764. Alternatively, a rhodium catalyst precursor, for example Rh 2 O 3, Rh 4 (CO) 12 or Rh 6 (CO) 16 and the like, may be introduced into the reaction medium. In a preferred embodiment, rhodium carbonyltriphenylphosphine acetylacetonate or rhodium dicarbonyl acetyl acetonate is used. In both cases, the active rhodium complex catalyst is formed in the reaction medium under the hydroformylation conditions, the alkyldiarylphosphine being formed in situ or added to the reaction medium, or both of these measures. It is also possible to prepare in advance a rhodium complex catalyst which contains both triarylphosphine and alkyldiarylphosphine complexed with rhodium.

The amount of catalyst present in the reaction medium should be at least the amount required to catalyze the hydroformylation of the α-olefin to form the product aldehydes. The rhodium content of the reaction medium may generally range from about 25 ppm to about 1200 ppm and preferably about 50 ppm to about 400 ppm, of catalytically active rhodium calculated as free metal.

The process of the invention can be expected to be suitable for hydroformylation of d-olefins having up to 20 carbon atoms.

The process of the invention is particularly suitable for the hydroformylation of G-olefins having from 2 to 5 carbon atoms, including ethylene, propylene, 1-butene, 1-pentene and the like, and this is preferred embodiments. The process according to the invention is particularly suitable for hydroformylation of propylene to butyraldehydes with a high ratio of normal: iso, i.e. the butyraldehyde predominating in the product is normal butyraldehyde, and this is a particularly preferred embodiment. The W-olefins used in the process of the invention may be straight chain or branched chain and may contain groups or substituents which do not substantially interfere with the hydroformylation reaction process.

The amount of olefin fed to the reaction depends on a number of factors, for example, the size of the reactor, the reaction temperature, the total pressure, the amount of catalyst, etc. In general, the higher the olefin content in the reaction medium, the lower is usually the catalyst concentration can be used to achieve a certain rate of conversion to aldehyde products of a reactor size. Since the partial pressures and the concentrations are related to each other, the use of higher olefin partial pressures results in an increased proportion of the olefin in the product stream leaving the reaction mixture. Furthermore, since a certain amount of saturated hydrocarbons can be formed by hydrogenating the olefin, it may be necessary to drain some of the product gas stream to remove this saturated product, before the material is returned to the reaction zone, and this is a source of loss of unreacted olefin present in the product gas stream. It is therefore necessary to balance the economic value of the olefin loss in such a drained purification stream against the economic gains associated with lower catalyst concentration.

The reaction temperature can, as indicated above, vary from about 100 to about 140 ° C, with lower temperatures favoring catalyst stability and higher temperatures favoring higher reaction rates. The particular temperature used in the reaction depends, of course, on the desired stability and reaction rate, but in general the advantages of the invention can be obtained by controlling the temperature to within this range.

A significant advantage of the process disclosed in U.S. Pat. No. 3,527,809 is the low total pressure of hydrogen and carbon monoxide required to carry out the hydroformylation reaction. The process of the invention operates at a low total pressure of hydrogen, carbon monoxide and carbon monoxide. 1-olefin less than ._____._......_....._._._.__... 7800871-1 -l9 about 31.5 ata and preferably less than about 24.5 ata. the total minimum pressure of these gases is not particularly critical and is mainly limited only by the amount of reaction gases required to obtain the desired reaction rate.

The additive gases fed to the reaction medium usually comprise olefin, carbon monoxide and hydrogen. As noted above, internal pollutants, such as sulfur and sulfur-containing compounds as well as halogens and halogen-containing compounds and the like, should be excluded from the additive gases, as such materials are known to poison the catalyst and can deactivate the catalyst relatively rapidly. It is therefore desirable to reduce the amount of such toxins in all gases added to the reaction.

The amount of such toxins that can be tolerated is of course determined by the maximum acceptable rate of activity loss for the catalyst. If it is possible to allow a certain small amount of such toxins and still obtain a catalyst with the desired stability, such small amounts can be tolerated. It is generally desirable to reduce the levels of such toxins in the auxiliary gases to less than one millionth. This can be accomplished by prior art methods. I I Hydrogen has some effect on catalyst deactivation. In the process of the invention, the partial pressure of hydrogen should be less than about 14 ata and preferably in the range of from about 1.4 to about 14 ata. The particular value used obviously depends on the desired stability and reaction rate as well as the relationship between the hydrogen partial pressure and the carbon monoxide partial pressure, as discussed below.

The partial pressure of carbon monoxide has a significant effect on the stability of the catalyst and should generally be lower than about 3.85 ata. The partial pressure used depends, of course, on the desired stability and reaction rate. As a general rule, lower partial pressures of carbon monoxide provide more stable catalyst. In the process of the invention it is suitable that the partial pressure of carbon monoxide is from about 0.07 ata to about 3.5 ata. The minimum partial pressure of carbon monoxide is not critical, as it is predominantly limited only by the desired reaction rate and the possibility of occurrence of hydrogenation of the olefin.

U.S. Pat. No. 3,527,809 states that the ratio normal: isoaldehyde in the aldehyde products decreases as the partial pressure of carbon monoxide increases relative to the hydrogen partial pressure. Similarly, in the process of the invention, the partial pressure of carbon monoxide in relation to the partial pressure of hydrogen has an effect on the isomer ratio of the product aldehydes. In general, in order to obtain the more desirable normal aldehyde isomer, the ratio of partial pressures of hydrogen: carbon monoxide should be at least about 2: 1 and preferably at least about 8: 1. As long as the partial pressures of carbon monoxide and hydrogen are regulated within the limits indicated above, there is no critical ratio of the partial pressures of hydrogen: carbon monoxide.

The reaction time or residence time of the olefin in the reaction zone is generally the period of time sufficient to hydraformylate the α-ethylene bond of the α-olefin. As a general rule, the residence time in the reaction zone can vary from about several minutes to about several hours and it is obvious that this variable is affected to some extent by the reaction temperature, the choice of 4-olefin and catalyst, the concentration of total free phosphine ligand , the total pressure, the partial pressure exerted by carbon monoxide and hydrogen, the degree of conversion or the rate of conversion and other factors. As a general rule, it is desirable to achieve the highest possible conversion rate for the least amount of catalyst used. Of course, the final determination of the conversion rate is affected by a number of factors, including the economics of the process. An essential advantage of the invention is that the catalyst stability is greatly improved by obtaining a very good conversion rate over a long period of time.

It is convenient to carry out the process according to the invention in the liquid phase in the reaction zone, which contains rhodium complex catalyst and, as solvent for it, the more high-boiling liquid aldehyde condensation products.

By the term "high-boiling liquid aldehyde condensation products" according to the invention is meant the complex mixture of high-boiling liquid products resulting from condensation reactions of certain aldehyde products in the process of the invention; as stated above. Such condensation products may be formed in advance or formed in situ. 7800871-1 The rhodium complex catalyst is soluble in these relatively high boiling liquid aldehyde condensation products and exhibits very good stability over a long period of time of continuous hydroformylation.

According to a preferred embodiment of the process according to invention n, the liquid high-boiling aldehyde condensation product, which is to be used as solvent, is preformed before introduction into the reaction zone and initiation of the process. It is also convenient to maintain the condensation products illustrated by acrolein II above, and isomers thereof, at low concentrations in the reaction medium, for example below about 5% by weight, based on the total weight of the reaction medium.

These high boiling liquid aldehyde condensation products are described in more detail as well as processes for their preparation in U.S. Pat. No. 4,148,830, and for a more detailed description reference is made to this patent application.

It is also convenient in the process of the invention to use the gas recirculation method described in U.S. Pat. No. 4,247,486. This gas recirculation method is generally described above. If the aforementioned high boiling liquid aldehyde condensation products are used as the reaction solvent, the liquid quantity in the reaction zone will contain a homogeneous mixture containing the soluble catalyst, free phosphine ligand, the solvent and product aldehydes and the reactants, carbon monoxide and olefin, carbon monoxide and olefins.

The relative proportion of each reaction product in the solution is controlled by the amount of gas passed through the solution. An increase in this amount reduces the equilibrium concentration of aldehyde and increases the rate at which by-products are removed from the solution.

The by-products include high-boiling liquid aldehyde condensation products. The reduction in the aldehyde content leads to a reduction in the rate of formation of the by-products.

The double effect of increased removal rate and decrease: formation rate means that the mass balance in the by-products in the reactor is very sensitive to the amount of gas carried through the quantity of liquid. The gas cycle typically includes addition amounts of hydrogen, carbon monoxide and u-olefin. The most important factor, however, is the amount of recycled gas which is converted to the quantity of liquid, since this determines the degree of reaction, the amount of product formed and the amount of by-product removed (as a consequence).

Carrying out the hydroformylation reaction at a given flow rate for olefin and synthesis gas (ie carbon monoxide and hydrogen) and with a total low amount of recycled gas, which is less than the critical threshold amount, results in a high equilibrium aldehyde content in solution and therefore a high rate of formation for by-products.

The amount of by-products removed per unit time in the vapor phase effluent from the reaction zone (the quantity of liquid) is low under such conditions, since the vapor phase effluent flow from the reaction zone can only lead to a relatively low rate of removal of by-products. The net effect is an accumulation of by-products in the liquid solution, which leads to an increase in the volume of the solution with a consequent loss of the productivity of the catalyst.

Therefore, a purge stream must be drained from the solution when the hydroformylation process is carried out under such low gas flow conditions to remove by-products and thus to maintain a mass balance within the reaction zone. However, if the gas flow through the reaction zone is increased by increasing the gas flow in the cycle, the amount of aldehyde solution decreases and the rate of formation of the by-products decreases while the rate of removal of by-products in the vapor phase effluent from the reaction zone increases. The net effect of this change is to increase the proportion of by-products removed with the vapor phase effluent from the reaction zone. An increase in the gas flow through the reaction zone further by a further increase in the gas cycle flow results in a situation in which the by-products in the vapor phase effluent are removed from the reaction zone at the same rate as they are formed and thus achieve mass balance over the reaction zone. This is the critical gas reflux threshold, which is the preferred minimum gas reflux used in the process of the invention. If the process is operated with a gas reflux greater than this threshold of the gas reflux, the volume of the liquid quantity in the reaction zone tends to decrease, whereby, at a gas reflux or gas cycle flow exceeding the threshold value, a certain portion of the crude aldehyde bypass is reproduced. from the product separation zone to keep the volume of the liquid phase in the reaction zone constant¿. .___._.__._._.: _-____._.__ V, 7800871-1 '23 The critical value of the gas cycle flow can be found with a number of random experiments with certain flows of olefin and synthesis gas (the mixture of carbon monoxide and hydrogen). Working with cycle flows below the critical threshold value increases the volume of the liquid phase over time. Working at the threshold value keeps the volume constant. Working above the threshold reduces the volume. The critical threshold of the gas circulation flow can be calculated from the vapor pressure at the reaction temperature of the aldehyde or aldehydes and from each of the by-products present.

When the process is carried out at a gas circulation flow at or greater than the threshold value, by-products in the vapor phase which are removed from the reaction zone, which contains the quantity of liquid, are removed at the same rate or faster than these are formed, so they do not accumulate in the liquid phase in the reaction zone. Under such conditions, it is unnecessary to drain a purification stream from the liquid quantity containing the catalyst from the reaction zone to remove by-products.

A by-product of the hydroformylation process is the alkane formed by hydrogenation of the α-olefin. In hydroformylation of propylene, for example, propane is a by-product; A purge stream can be withdrawn from the gas cycle stream from the product recovery zone to remove propane and to prevent its accumulation in the reaction system. This purification stream contains, in addition to the undesired propane, unreacted propylene, any inert gases introduced into the starting material and a mixture of carbon monoxide and hydrogen. This purification stream may, if desired, be subjected to conventional gas separation methods, for example cryogenic methods, for the recovery of propylene, or it may be used as a fuel. The composition of the recycle gas is mainly hydrogen and propylene. However, if the carbon monoxide is not completely consumed in the reaction, the excess carbon monoxide also forms part of the recycle gas. Usually the recycle gas contains alkane even when a purge stream is drained before being recycled.

The preferred gas cycle is further illustrated with reference to Figure 5, which schematically shows a diagrammatic flow chart suitable for carrying out the preferred cycle process according to the invention.

The drawing figure shows a reactor 1 of stainless steel, which 7800871-1 24 'is provided with one or more disk stirrers 6 comprising vertical, mounted blades, which are caused to rotate with a shaft 7 and a linklif motor (not shown). Under the stirrer 6 there is a circular supply pipe 5 for supplying α-olefin and synthesis gas plus circuit. flea gas. The supply pipe 5 is provided with a plurality of heels of a size sufficient to provide a sufficient gas flow into the liquid quantity at the stirring device 6 and so that the desired amount of the reaction components is introduced into the quantity of liquid. The reactor is also provided with a steam jacket (not shown; with which the contents of the vessel can be heated to the reaction temperature at start-up and with internal cooling coils (not shown). Vaporous product effluent from the reactor 1 is removed through a line 10 to a separator 11, where the steam The reactor effluent is passed through a line 13 to a condenser 14 and then through a line 15 to a collection container 16, in a mist separation pad 11a for returning a certain part of the aldehyde and the condensation product and to prevent potential transfer of the catalyst. which aldehyde product and any by-products can be condensed out of the exhaust gas (effluent). Condensed aldehyde and by-products are removed from the collection vessel 16 through a line 17. Gaseous materials are passed through a line 18 to a separator 19 containing a mist separating pad and a recycle gas through the loop gas line 20. a line 2, to line 8, from v which a purge stream is branched through a line 22 for regulating the content of saturated hydrocarbon and for maintaining a desired system pressure. The remaining main part of the gases can be recycled through line 8 to line 4, into which supplementary reactants are introduced through lines 2 and 3. The combined total amount of reactants is fed into the reactor 1. A compressor 26 contributes to the transport of the gases circulated. .

Fresh catalyst solution can be added to the reactor 1 through a line 9. The single reactor 1 can of course be replaced by a plurality of reactors.

The crude aldehyde product in line 17 can be treated by conventional distillation to separate the various aldehydes and condensation products. A portion of the crude product can be returned in cycle to the reactor 1 through a line 23 and fed as indicated in line 71-1 with a dashed line 25 to a point above the agitator 6 for maintaining the liquid level in the reactor 1 if required.

As noted above, the most preferred embodiment of the invention is hydroformylation of the α-olefin propylene to form butyraldehydes which are predominantly the normal isomer. The stability of the rhodium complex catalyst is improved using the process of the invention and in the case of propylene the reaction is controlled under the following conditions: temperature: about 100 to about 140 ° C total gas pressure of hydrogen, carbon monoxide and propylene: less than about 31.5 ata carbon monoxide partial pressure: about 0, 07 to about 2.8 ata hydrogen partial pressure: about 1.4 to about 14 ata molar ratio total amount of free phosphine catalytically active rhodium: about 75 to about 500 triarylphosphine: triphenylphosphine alkyldiarylphosphine: propyldiphenylphosphine.

Examples 1-30.

In all of these examples, the same approach was used, as set forth below. In a stainless steel reactor, a rhodium hydroformylation solution containing rhodium in the form of rhodium carbonyltriphenylphosphine-acetylacetonate and the amounts of triphenylphosphine and propyldiphenylphosphine listed in Table II below were charged to a mixture of butyraldehyde and butyraldehyde 2 -trimers. , 4-trimethylpentyl isobutyrate). An equimolar mixture of propylene, carbon monoxide and hydrogen was charged to the reactor and the rate (rl) of butyraldehyde formation at 100 ° C was determined by measuring the time required for a certain pressure drop in the reactor.

After the reaction, the gases were removed from the reactor and replaced with a mixture of hydrogen and carbon monoxide at the partial pressure given in Table II. The reactor containing these gases was heated for about 3 hours to the temperature given in Table II. The gases were released and an equimolar mixture of propylene, carbon monoxide and hydrogen was charged again in the reactor and a second hydroformylation experiment was carried out at the same temperature as in the first experiment. A second rate (r2) for butyraldehyde formation was determined in the same manner as above. 7800871-1 26 The results are given in Table II below.

Examples 1-20 are within the scope of the invention and illustrate the improved stability obtained using an alkyldiarylphosphine in the reaction medium. Examples 21 - 30 ä; comparative experiments, since no alkyldiarylphosphine was used. vaooevá-1 A27 ~ ow fi m «N om fl mo G wmm @ .ßm vw om fi oH o_ @ ßw fi m.mm mm om fi oH om www w_« ~ mm oa fl m om mß fi m \ mw mw> H ~ NQ om fl m.mw Nw NAN mw mß fi o_m @ mm Hm ~ wm om fl o _ >> w fi mw fi N m oow ~ _om ww man v m.> Om fl H. «m om ow fl v om oom ~ .m> mm www N m.> Om fl mo @ mm Nm fi N m_ß oow m_mm aw fi mw «m øm fl m.ßw ww mmm v m.> Oow N.> ß mm amd ~ m om fi wmuw> Hwmno uwwwpnwwm _m.zm \ A. ~ .Mmnm A fi vmms .smmv ^«. ^ @ . »Wp fi> fl» x <_ Ammmmmmmmmmw fl H fi mwmw _ wmcmäwcmm fifi.

HNßOB ÉOMWW .SM wmqwz .HH HHQQMB s mw ~ w mw.w ä n.

KO's B A D '§ ä ns ~ called al kDkbw flfifl k fl lñl- fi ~ s ~ s ~ ns ~ w ~ nn 01 mf f mf f mdïmmmk al kßßw ~ u V3 Nww al NwßüNwNNllïNwkb ä f NN fifl NN f N fifl f fi RNV al J, ml mm .mumv xuhuu l fi et al uumm OMH If fi If fl m NH ONH ONH MAA m NH mw al mN fl mNH maa m fifi maa maa AUOV fl mm Høumu lmmäwv | mGO fl uxmmm ma wa ma N fl ul rI O rI Plñlf fifi lñk fl ßæm Iäwxm 28 oo fi x _Hu \ ~ H. n ow »fl> fi» xm w ^ «.

H fi mpwæ fi ø fl uoo fl s fl mwow fi mpop wocm flfl msoom fi oa U sm \ q Am. 7800871-1 n fl wmooH »q @ m« oH> ooHo H mono ^ ~ v o fl owo «H> nwo fl ~» N mma. ^ ~ V mowv »oo oo fi o o. ~ Wß m ~« m_ ~ o ~ H om m_mw mm oo fl o o_N wß ~ _HH> _o om mm «.m> o oß m ~ o o.« www o_m> .m om o mw ß_o «mq mm o o.« www o_m> _o om fi> ~ o_Hm mm mm o o_H wm fi @_m> .o om om mw> om wß o o_m omw ~ _HH «_H oo fi mw womß mß wß o om omm ~ .HH w_ ~ oo fl« N m. ~ ßm wo mo m »~ N.HH æ_ ~ o fifl MN w_ «H m.« Fl om o mN m> ~ ~ _HH w. ~ Om fi NN ~ _ «fi o.mH mm o m. ~ Mmm ~ _fifl w_ ~ o om fi HN mo> o_H« om fl o_m ow mom mæ . @ @. «Om fi o ~ ßwww mm om fi o_m o_m www mw_ @ ~ _m o ~ H ma mm> mm om fi o_ fl o_w» wa mw_ @ Nm QNH w fl «.Hw H« om fl oH om oo fl mw_oo o. «Ow fi» H mw «m.mm wm fl m oo w« ~ mw.w ~ _m om fl w fl .mv fl un fl xwHwm fl ø ÜÜÜMPÜHÛN mmm ... _ a AQOJ. .JMG ^ «v. @ V uw» fi> fl px «Apcwoou u» fl> v H fi mwme |||||| «mmm fl Mmmm» lswxm _ 1 Umcmšwcmm flfi Eommw. m xuænv mcow mwu Hmpoa wwømm | Hm fi pnmm | The predicted activity values set forth in Table II were calculated using the stability formula set forth above and set forth in the aforementioned patent application with Applicant Bryant and Billig. The values in Table II show a marked improvement in the catalyst stability when propyldiphenylphosphine is present, which is evident when comparing the right observed value for the activity in% compared with the predicted percentage activity values for these examples.

Examples 31 - 37.

In all of these experiments, essentially the same procedure was used, as set forth below. A hydroformylation reaction was carried out in a stainless steel reactor using various alkyldiphenylphosphines in the same manner as in Examples 1-30. The initial partial pressure of the reactants propylene, carbon monoxide and hydrogen was the same in all examples. The rate of butyraldehyde formation was determined at several times during the reaction and the results are given in Table III. 7800871-1 .cmco al uxmmu bd ßwßø f m w> al uxwmmwH f m f UMN U fl b mn f n f a f nwæsmu fi mnhu f n Mmm msuuvmnm al umms um NH ßuo HH wH> Mm> ~ OOA x AHH \ NHV u umß fl b fl UXM w H f ~ »@ AAO fi OOH \ nHumo« H »a @ w f wH> MH« ømnwa Hmpou mwqm fifi wnumw fi oa H nm \ mmnm _ _ øwa fl wmow fl wnww fi v fi mx fl m H Hwx fl m HM .vv Am.

AN. m ¶ H fi mu @ ssn fl øoH \ a fl wmomH> n @ w fl uv Have »mwø flfifi mnnmw fl os H = m \ mma .H. wnmw: Hw fifi w wa wa m «wo w« wo m H> moum om Fm mummn Hw fifi w wm mm «fl w.o @ mw.ow H> monm« ~ wm vw A ww «o. fi ~ m. ~ m Hwusm ma mm vß mß @oH mm.H m H> moum ma Qm mm Hb mm.o fi m.H m Hwum mä mm Nm om> «. o wm.om Hwpwz md Nm m_mm ww m> .H m> .mo | o ~ .Hm Hmu flflfl ñ Om Ha fl u uwuH> fl uxm Awv u flfl m mGw fl0fi # E fl ä fl xmä ^ Hvnm \ mmB Hwm fi wkm fl mxmmüm M mc fl um fi ommuuxm Av. uxmmu U fi> Am. _ ^ N, umv fl> fl ß ¥ mw As x Hmu flfl \ HOEv umnm fi pmmswma fi aw flfi nwænww fi mnwunm .HHH HHGQMB 7800871-1 31 As shown in Table III, in particular when comparing Examples 32 - 37 (which illustrate the invention). ), the use of an alkyl diphenylphosphine ligand in the reaction medium improves the stability of the catalyst.

Example 38 - 45.

These examples were carried out in the same manner as in Examples 31, except that the ligand used consisted only of alkyldiphenylphosphine in Examples 38-42 and 45 and only triaryl-phosphine in Examples 43 and 44. The invention is not intended to include the use of these ligands alone. The results are given in Table IV. 78-00871-1 32 oo fl x ^ »wnm fi pmmn fl a fl xma \ n H wH> uwsw fl uwmnv n M Amv. HH H fi mnmu um flfi nm Eow mä fi mm HH HHUQMQ NÜHHGÜ EOW MEEMW HM ^ Hv_ mm mæ.o «wo om fi omw o fi Nß ww.o mm.o om om fl ma mm> m_o H> _H ow omw ca mm @mo m @ _o oo fi omm @ .oH ßm mw.H «~ _m oo fl omm QÅQ mm ww.o mm_o oo fl omm o fl mm mw.o> wo oo fl omw o fi wæ @N_H m« .H mm fl omm H_oH Amvw QH u fl> ¶ pwnw fl pwmß Auo. .am @. . ~ .§M \ q äw fi ü fifl mßm IHEHXNÉ HSNNHQQEWH HHMHÜE fl hw ._ An x Hwu fi H \ HoEv pwßm fl pmßßmwn fl uu fifi n @> zmøHm ~> »:: Hæmoumom flfl æmoumlc fi æum fi æpwz: cm mw ww mw ~ «Hw ow. mm mm Hmuëmwm

Claims (14)

1. as 7800-871--1 PATENT REQUIREMENT 1; Process for hydroformylating an arolefin containing 2-20 carbon atoms to produce aldehydes containing one carbon atom more than the α-olefin by reacting the Q-olefin with hydrogen and carbon monoxide in a liquid reaction medium containing a soluble rhodium complex catalyst consisting essentially of rhodium monoxide complexed and a triarylphosphine ligand, and in the presence of free triarylphosphine characterized in that the stability of the catalyst is improved by charging the liquid reaction medium containing the catalyst with from about 0.1 to 20% by weight of an alkyldiarylphosphine ligand based on the total weight of the liquid reaction medium, and regulating the reaction conditions to a temperature of from about 100 ° to about 140 ° C, a total gas pressure of hydrogen, carbon monoxide and α-olefin lower than about 31.5 ata, a carbon monoxide partial pressure below about 3.85 ata, a hydrogen partial pressure below about 14 ata , and at least about 75 moles of total free phosphine ligand per mole of catalytically active rhodium metal present in the rhodium complex catalyst consisting essentially of rhodium complexed with carbon monoxide and one or both of said triarylphosphine and said alkyldiarylphosphine. Process according to Claim 1, characterized in that the urolefin has 2-5 carbon atoms. 3. A process according to claim 1 characterized in that the drolefin is propylene. 4. A process according to claim 1 wherein the α-olefin is ethylene. Process according to Claim 1, characterized in that the orolefin is 1-butene. 7800871-1 34 6. A process according to claim 1 characterized in that the triarylphosphine is triphenylphosphine. 7. The process of claim 1 wherein the partial pressure of carbon monoxide is from about 0.07 to about 3.5 ata. A process according to claim 1 characterized in that the amount of alkyldiarylphosphine is from about 0.5 to about 10% by weight, based on the total weight of the liquid reaction medium. 9. A process according to claim 1 characterized in that the molar ratio of total free phosphine catalytically active rhodium metal is at least about 100. 10. The process of claim 1 wherein the total gas pressure of hydrogen, carbon monoxide and crolefin is less than about 24.5 ata. 11. ll. A process according to claim 1, characterized in that the partial pressure of hydrogen is from about 1.4 to about 14 ata. 12. A process according to claim 3 characterized in that the ratio of the partial pressures of hydrocarbon monoxide is at least about 2: 1. 13. A process according to claim 1 characterized in that the ratio of the partial pressures of hydrogen carbon monoxide is at least about 8: 1. 14. A process according to claim 1 characterized in that the catalyst is dissolved in a solvent comprising the high-boiling liquid condensation products of alde-. hyderna.