JP4412066B2 - Method for producing aldehyde - Google Patents

Description

  The present invention relates to a method for producing an aldehyde in which catalytic activity is maintained.

  Traditionally, processes for producing aldehydes by hydroformylation of olefins in the presence of a catalyst are known and are commercially available worldwide. Many known documents relating to these hydroformylation reactions are known. Usually, the pressure in an industrial hydroformylation reaction is about 2 MPaG to 20 MPaG in the past, and about 1 MPaG even when the pressure is reduced, and the reaction is performed in order to maintain the reaction rate. In order to pressurize the inside of the reactor, the reactor needs to be sealed.

  On the other hand, in order to produce aldehyde evenly, it is necessary to stir the reactor with a stirrer, and Patent Document 1 discloses that the shaft portion that transmits the power of the stirrer from the outside to the inside of the reactor can be sealed. In general, a mechanical seal is provided.

  In this mechanical seal, the space between the shaft and the mechanical seal is sealed with a sealing liquid made of mineral oil or the like. There is a method as described in Patent Document 2 so that this sealing liquid originally exists only in the mechanical seal portion and does not enter the reactor.

Japanese Utility Model Publication No. 3-98936 Japanese Utility Model Publication No. 6-29628

  However, depending on the type of sealing liquid used for sealing, there is a possibility that the activity of the catalyst used for the hydroformylation reaction may be lost if it is mixed in the reactor even in a trace amount.

  Accordingly, an object of the present invention is to suppress adverse effects caused by the mixing of a sealing liquid in a reactor when an aldehyde is produced by a hydroformylation reaction using a reactor equipped with a stirrer.

  In the present invention, when a hydroformylation reaction is performed using a reactor equipped with a stirrer, a liquid material that does not substantially reduce the catalytic activity of the catalyst used in the hydroformylation reaction is used as a seal liquid for the mechanical seal of the stirrer. The above-mentioned problems are solved by a method for producing aldehyde characterized by the following.

  According to the present invention, even if the sealing liquid used for sealing is mixed in the reactor, the production of aldehyde can be continued without losing the activity of the catalyst used for the hydroformylation reaction.

Hereinafter, the present invention will be described in detail.
In the present invention, when a hydroformylation reaction is performed using a reactor equipped with a stirrer, a liquid material that does not substantially reduce the catalytic activity of the catalyst used in the hydroformylation reaction is used as a seal liquid for the mechanical seal of the stirrer. An aldehyde production method characterized by the following.

  The fact that the catalytic activity is not substantially lowered means that the catalytic activity is substantially maintained. Specifically, the reaction rate of the olefin in the hydroformylation reaction described later in the case where the seal liquid is mixed in the reaction system in such an amount that the concentration of the liquid material used as the seal liquid is 10 wt%. The decrease is 5% or less, and more preferably 3% or less.

  As said liquid substance, it is desirable that it is a substance separable from the product aldehyde obtained by the hydroformylation reaction mentioned later, or a product aldehyde itself.

  When the liquid is a component other than the product aldehyde, the quality of the product aldehyde is deteriorated unless the sealing liquid mixed in the stirring tank 11 is removed. Therefore, it is necessary to be separable from the aldehyde. It is desirable that it be easy. Examples of the sealing liquid having such properties include toluene and xylene.

  On the other hand, by using the same substance as the product aldehyde as the sealing liquid, even if the sealing liquid is mixed into the stirring tank 11, the catalytic activity cannot be substantially reduced. Examples of the product aldehyde that can be used as the sealing liquid include propanal, butanal, pentanal, hexanal, heptanal, octanal, nonanal, and the like. Among these, hexanal, heptanal, octanal, and nonanal are preferable.

  Moreover, not only the product aldehyde itself, but also the alcohol obtained by hydrogenating the product aldehyde and the alcohol obtained by hydrogenating the dimerized product aldehyde do not substantially reduce the catalytic activity. A thing may be used as the sealing liquid. Furthermore, when the product aldehyde obtained by the production method according to the present invention is processed into these alcohols or the like, even if the sealing liquid composed of these is mixed, the quality of the product is finally affected. Do not leave.

  The product aldehyde used in these sealing liquids, the alcohol obtained by hydrogenation of the product aldehyde, and the alcohol obtained by hydrogenation of the product aldehyde dimerized preferably have a boiling point of 15 ° C. or more higher than the operating temperature. . This is because the temperature at the sliding portion may be 15 ° C. or more higher than the operating temperature.

  Examples of the alcohol obtained by hydrogenating the above product aldehyde include propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-hebutanol, 1-octanol, and the like. Desirable are 1-pentanol, 1-hexanol, 1-heptanol, and 1-octanol.

  As alcohol obtained by hydrogenating what dimerized said product aldehyde, 2-ethyl- hexanol, 2-propyl- heptanol, etc. are mentioned, for example.

  Said hydroformylation reaction is reaction which produces | generates the aldehyde which carbon number increased 1 from the original olefin by making olefin etc. react.

  Although the olefin used for a raw material in said hydroformylation reaction is not specifically limited, Generally a C2-C8 olefin is desirable among a linear or branched alpha olefin or an internal olefin. Specific examples of these olefins include ethylene, propylene, 1-butene, 2-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, etc. Among these, ethylene, propylene, 1 -Butene, particularly preferably propylene.

  Aldehydes produced from these olefins vary in type and yield depending on the raw materials and the catalyst used, but are aldehydes having at least 3 carbon atoms. Specific examples include propanal, butanal, pentanal, hexanal, Examples include heptanal, octanal, nonanal and the like, among which propanal, butanal and pentanal are desirable, and butanal is particularly desirable.

  An example of the reactor equipped with a stirrer for producing the aldehyde according to the present invention is shown in FIG. A shaft 14 that serves as a stirrer by connecting an external motor 12 and an internal stirring blade 13 passes through a stirring tank 11 that is a reactor body that performs the reaction, and the shaft 14 is in contact with the outer wall of the stirring tank 11. A mechanical seal 15 for sealing the stirring tank 11 is provided. The raw material olefin and a catalyst, reaction solvent, carbon monoxide, and hydrogen gas or hydrogen halide serving as a hydrogen atom source are supplied to the stirring vessel 11 continuously or batchwise. To produce an aldehyde with stirring.

  Examples of the reaction solvent include condensates of the above product aldehyde, aliphatic hydrocarbons such as hexane and octane, aromatic hydrocarbons such as toluene and xylene, alicyclic hydrocarbons such as cyclohexane, butanol, octanol, and polyethylene glycol. And solvents such as alcohols such as triglyme, esters such as dioctyl phthalate, water and the like that dissolve the catalyst and do not affect the reaction. Specific examples of the product aldehyde condensate include product aldehyde trimers and tetramers. Paraffins having the same carbon number as the raw material olefin may be used. Among these, toluene and the above condensates are preferable because they are easily separated from the reaction product and have little influence on the reaction.

  An example of an enlarged view near the mechanical seal 15 is shown in FIG. The stirring tank 11 is sealed by the seal piece 21 in contact with the shaft 14, and the sealing liquid is poured into the sealing liquid space 22 from the sealing liquid supply port 23, thereby filling the gap remaining with the sealing liquid and sealing it. These structures are not particularly limited to the shape shown in FIG. 2, and any structure can be used as long as the periphery of the rotating shaft 14 can be sealed by the sealing piece 21 and the sealing liquid, and the sealing liquid space 22 has a plurality of stages. It is more desirable if it is a structure in which the sealing performance is further enhanced, such as multiple sealing by the sealing piece 21. Here, the sealing piece 21 needs to have a structure that can seal the stirring tank 11 together with the sealing liquid, or has a structure that is in close contact with the shaft by a spring or the like. For example, a seal piece made of fluororesin, carbon graphite, silicon carbide, or the like is effectively used.

  In order to seal between the sealing piece 21 and the shaft 14, the sealing liquid for sealing needs to enter between the sealing pieces 21 and the shaft 14, and may leak into the stirring tank 11. Therefore, even if the sealing liquid leaks from the mechanical seal 15 part and enters the stirring tank 11 by using a liquid material that does not substantially reduce the catalytic activity of the catalyst used in the hydroformylation reaction as the sealing liquid, The production of aldehyde by the catalyst is not hindered.

  The catalyst that does not substantially reduce the activity according to the present invention is not particularly limited as long as it is a catalyst that can convert an olefin into an aldehyde, and examples thereof include a cobalt complex and a rhodium complex.

  Examples of the cobalt complex include octacarbonyl dicobalt and hexacarbonyldi (triphenylphosphine) cobalt.

  As the rhodium complex, a complex having a trivalent organic phosphorus compound as a ligand is particularly desirable. As said trivalent organophosphorus compound, the trivalent organophosphorus compound used as a monodentate ligand and the trivalent organophosphorus compound which has the capability as a multidentate ligand are mentioned.

  Examples of the trivalent organophosphorus compound that becomes a monodentate ligand include triorganophosphine represented by the following formula (1).

In said formula (1), R < ¹ > -R < ³ > is a monovalent hydrocarbon group and may have a substituent. As this R < ¹ > -R < ³ >, C1-C12 alkyl group and alkoxy group, C3-C12 cycloalkyl group and cycloalkoxy group, C3-C12 aryl group, C6-C6 24 alkylaryl group, C6-C24 arylalkyl group, etc. are mentioned. That is, specific examples of the triorganophosphine having these substituents include trialkylphosphine, triarylphosphine, tricycloalkylphosphine, alkylarylphosphine, cycloalkylarylphosphine, and alkylcycloalkylphosphine. .

  Specific examples of the triorganophosphine include tributylphosphine, trioctylphosphine, triphenylphosphine, monobutyldiphenylphosphine, dipropylphenylphosphine, cyclohexyldiphenylphosphine, and the like. The most preferred triorganophosphine is triphenylphosphine.

  Other examples of the trivalent organophosphorus compound include, for example, trivalent phosphite compounds represented by the following formulas (2) to (11).

In said formula (2), R < ⁴ > -R < ⁶ > shows an independent hydrocarbon group, respectively, and may have a substituent. Examples of such hydrocarbons include alkyl groups, aryl groups, cycloalkyl groups, and the like.

  Specific examples of the compound represented by the above formula (2) include, for example, trimethyl phosphite, triethyl phosphite, n-butyl diethyl phosphite, tri-n-butyl phosphite, tri-n-propyl phosphite, tri -Trialkyl phosphites such as n-octyl phosphite and tri-n-dodecyl phosphite, triaryl phosphites such as triphenyl phosphite and trinaphthyl phosphite, dimethylphenyl phosphite, diethylphenyl phosphite, ethyl diphenyl phosphite Examples thereof include alkylaryl phosphites such as phytes. Further, for example, bis (3,6,8-tri-t-butyl-2-naphthyl) phenyl phosphite, bis (3,6,8-tri-t-butyl-2-naphthyl) (4-biphenyl) phos Fight or the like may be used. Among these, the most desirable is triphenyl phosphite, and a preferable rhodium complex using this is, for example, tris (triphenyl phosphite) rhodium.

In the above formula (3), R ⁷ represents a divalent or higher hydrocarbon group, and R ⁸ represents a monovalent hydrocarbon group. Moreover, either may have a substituent. As R ⁷ , an alkylene group which may contain an atom such as oxygen, nitrogen or sulfur in the middle of the carbon chain, or a cycloalkylene group which may contain an atom such as oxygen, nitrogen or sulfur in the middle of the carbon chain. , Divalent aromatic groups such as phenylene and naphthylene, divalent aromatic groups in which a divalent aromatic ring is bonded directly or in the middle via an atom such as an alkylene group, oxygen, nitrogen, sulfur, etc. A group in which a group group and an alkylene group are bonded directly or in the middle through an atom such as oxygen, nitrogen, or sulfur. Examples of R ⁸ include an alkyl group, an aryl group, and a cycloalkyl group. Specific examples of the compound represented by the above formula (3) include, for example, neopentyl (2,4,6-t-butyl-phenyl) phosphite, ethylene (2,4,6-t-butyl-phenyl) phosphine. And compounds such as phyto. Another desirable example is a compound represented by the following formula (4).

In the above formula (4), R ⁹ is a monovalent hydrocarbon group that satisfies the same conditions as R ⁸ in the above formula (3), and Ar ¹ and Ar ² may be independently substituted. An arylene group, x and y are each 0 or 1, and Q is —CR ¹⁰ R ¹¹ —, —O—, —S—, —NR ¹² —, —SiR ¹³ R ¹⁴ —, and —CO—. Each of R ¹⁰ and R ¹¹ is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a phenyl group, a tolyl group, or an anisyl group, and R ¹² , R ¹³ , And R ¹⁴ is a hydrogen atom or a methyl group, and n is 0 or 1. Specific examples of the compound represented by the above formula (4) include 1,1′-biphenyl-2,2′-diyl- (2,6-di-t-butyl-4-methylphenyl) phosphite, 3 , 3'-di-t-butyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'-diyl- (2-t-butyl-4methoxyphenyl) phosphite. .

In the above formula (5), R ¹⁵ represents a trivalent hydrocarbon group which is cyclic or acyclic. Specific examples of the compound represented by the above formula (5) include compounds such as 4-ethyl-2,6,7-trioxa-1-phosphabicyclo- [2,2,2] -octane. .

In the above formula (6), R ¹⁶ represents a divalent or higher valent hydrocarbon group that satisfies the same conditions as R ⁷ in formula (3), and each of R ¹⁷ and R ¹⁸ may have a substituent. It is a good hydrocarbon group, a and b are each an integer of 0 to 6, the sum of a and b is 2 to 6, and X ¹ is an (a + b) -valent hydrocarbon group. Specific examples of the compound represented by the above formula (6) include 6,6 ′-[[3,3 ′, 5,5′-tetrakis (1,1′-dimethylethyl)-[1,1′- Biphenyl] -2,2′-diyl] bis (oxy)] bis-benzo [d, f] [1,3,2] dioxaphosphine and the like. Other desirable examples include compounds represented by the following formulas (7) to (11).

In the above formula (7), X ² is a divalent group consisting of any one of alkylene, arylene, and —Ar ¹ — (CH ₂ ) _x —Q _n — (CH ₂ ) _y —Ar ² —, and R ¹⁹ And R ²⁰ each represents a hydrocarbon group which may have a substituent. Ar ¹ , Ar ² , Q, x, y, and n are the same as in the above formula (4). Specific examples of the compound represented by the formula (7) include, for example, compounds described in JP-A-62-116587.

In the above formula (8), X ² , Ar ¹ , Ar ² , Q, x, y, n are synonymous with the above formula (7), and R ²¹ is synonymous with R ⁷ in the above formula (3).

In the above formula (9), R ²² and R ²³ are each an aromatic hydrocarbon group which may have a substituent, and at least one of them is a carbon atom adjacent to the carbon atom to which the oxygen atom is bonded. Has a hydrocarbon group, m is an integer of 2 to 4, each —OP (OR ²² ) (OR ²³ ) group may be the same as or different from each other, and X ³ is substituted It is an m-valent hydrocarbon group that may be used. Specific examples of the compound represented by the above formula (9) include, for example, the compounds described in JP-A No. 5-17879, 2,2′-bis (di-1-naphthyl phosphite) -3,3. The compounds described in JP-A-10-45776 such as', 5,5'-tetra-t-butyl-6,6'-dimethyl-1,1'-biphenyl are desirable.

In the above formula (10), R ^{24 to} R ²⁷ are hydrocarbon groups which may have a substituent, may be independent of each other, and R ²⁴ and R ²⁵ , R ²⁶ and R ²⁷ may be bonded to each other to form a ring, X ⁴ is a divalent aromatic hydrocarbon group that may have a substituent, and L may have a substituent. A divalent aliphatic hydrocarbon group which is saturated or unsaturated. Specific examples of the compound represented by the above formula (10) include, for example, compounds described in JP-A-8-259578.

In the above formula (11), R ^{28 to} R ³¹ are monovalent hydrocarbon groups which may have a substituent, and R ²⁸ and R ²⁹ , R ³⁰ and R ³¹ are bonded to each other to form a ring. Or A ¹ and A ² are each independently a divalent aromatic hydrocarbon group which may have a substituent, and n is 0 or 1 It is.

  In the present invention, the rhodium source constituting the catalyst includes a hydrogen supply source that is carbon monoxide, hydrogen, or hydrogen halide outside the stirring tank 11 serving as a reactor, and trivalent organic phosphorus of the above formulas (1) to (11). Along with the compound, the reaction temperature is 40 ° C. or higher, preferably 50 ° C. or higher, more preferably 60 ° C. or higher, 300 ° C. or lower, preferably 200 ° C. or lower, more preferably 150 ° C. or lower, and 0 The rhodium complex catalyst is prepared in advance by reacting under a pressure environment of 0.001 MPaG or more, desirably 0.01 MPaG or more, more desirably 0.1 MPaG or more, 20 MPaG or less, desirably 10 MPaG or less, more desirably 5 MPaG or less. It is desirable to keep it. In addition, G in a unit means a gauge pressure. If the pressure is too low, the reaction rate becomes slow and sufficient reaction may not be performed. On the other hand, if the pressure is too high, the design pressure of the preparation equipment increases and the equipment burden increases.

  The treatment time in preparing the rhodium complex is usually 5 minutes or more, desirably 10 minutes or more, more desirably 30 minutes or more, 15 hours or less, desirably 5 hours or less, more desirably 3 hours or less. is there. If the treatment time is too short, the reaction does not proceed sufficiently and catalyst activity may not be obtained. On the other hand, if it is too long, the catalytic activity will decrease.

  The solvent used in preparing the catalyst is usually selected from those described in the above reaction solvent, but is not necessarily the same solvent as the above reaction solvent. As conditions for the preparation, the rhodium concentration is usually 1 wtppm or more and more preferably 10 wtppm or more, while it is 10 wt% or less, preferably 1 wt% or less, and more preferably 1000 wtppm or less. If the rhodium concentration is too low, the reaction rate becomes slow, and sufficient reaction may not be achieved. On the other hand, if it is too high, the high-boiling substances are extracted when they are purged, so that loss of expensive rhodium increases.

  When adjusting the rhodium complex, the ratio (P / Rh) of mixing the trivalent organophosphorus compound and rhodium is usually 1 or more and 10,000 or less, preferably 1000 or less in terms of molar ratio, The following is more desirable. If the amount of the trivalent organic phosphorus compound is too small, the coordination amount to rhodium is reduced, so that rhodium may not be sufficiently stabilized. On the other hand, when there are too many said trivalent organophosphorus compounds, the density | concentration in a reaction system will become high, and when purging a high boiling thing, it will be extracted and will increase loss.

  When a hydroformylation reaction for increasing the number of carbon atoms to olefin by these catalysts is performed, hydrogen atoms are added together with carbon monoxide using hydrogen or a hydrogen halide such as hydrogen iodide.

  As the reaction conditions for performing the above hydroformylation reaction, when hydrogen gas is used as the hydrogen atom source, the hydrogen partial pressure is usually 0.0001 MPa or more, preferably 0.01 MPa or more, more preferably 0.1 MPa or more. Yes, 20 MPa or less, desirably 10 MPa or less, more desirably 5 MPa or less. If the hydrogen partial pressure is too low, the reaction rate decreases too much, and if it is too high, the proportion of by-products increases too much.

  The carbon monoxide partial pressure during the above hydroformylation reaction is usually 0.0001 MPa or more, desirably 0.01 MPa or more, more desirably 0.1 MPa or more, 20 MPa or less, desirably 10 MPa or less, more desirably 5 MPa or less. If the carbon monoxide partial pressure is too low, the reaction hardly proceeds. On the other hand, if the carbon monoxide partial pressure is too high, the partial pressure of the olefin is too low and the reaction hardly proceeds.

  The total pressure during the hydroformylation reaction is usually 0.0001 MPaG or more, preferably 0.01 MPaG or more, more preferably 0.2 MPaG or more, and usually 50 MPaG or less, preferably 30 MPaG or less, more preferably 20 MPaG or less. is there. If the total pressure is too low, the reaction rate will be too slow and sufficient reaction will not be possible. On the other hand, if it is too high, the design pressure of the reactor will be too high and the equipment burden will increase too much.

  The ratio of (hydrogen partial pressure / carbon monoxide partial pressure) in the above hydroformylation reaction is usually 0.1 or higher, more preferably 1 or higher, 100 or lower, preferably 10 or lower, more preferably 6 or lower. is there. If this ratio is too small, the reaction will not proceed sufficiently. On the other hand, if it is too large, the reaction will not proceed sufficiently or the proportion of by-products will increase.

  When the rhodium complex is used, the reaction temperature at the time of performing the above hydroformylation reaction is usually 20 ° C or higher, desirably 40 ° C or higher, more desirably 50 ° C or higher, and usually 200 ° C or lower, desirably 150 ° C. It is as follows. If the reaction temperature is too low, the reaction does not proceed sufficiently, and if it is too high, the amount of by-products generated may increase or the above catalyst may be deactivated.

  When the rhodium complex is used as a catalyst when the hydroformylation reaction is performed, the rhodium concentration relative to the entire reaction system is usually 1 wtppm or more, preferably 10 wtppm or more, preferably 10 wt% or less, preferably 1 wt% in terms of rhodium metal atoms. % Or less, more desirably 1000 wtppm or less. If the rhodium concentration is too low, the reaction rate becomes too slow to perform a sufficient reaction. If the rhodium concentration is too high, rhodium is lost too much because it is taken out when purging high boiling substances.

  In the above hydroformylation reaction, when a rhodium complex having a trivalent organophosphorus compound or the like shown in the specific examples in (1) to (11) as a ligand is used, the hydroformylation reaction consists of the above trivalent organophosphorus compound. The molar ratio (P / Rh) between the free organophosphorus ligand and rhodium is usually 0.1 or more, preferably 1 or more, and usually 10,000 or less, desirably 1000 or less, and more desirably 100 or less. If this molar ratio is too low, rhodium may be deactivated without being sufficiently stabilized.If it is too high, the concentration in the reaction system will increase, and high boiling substances will be extracted when purging. This results in too much rhodium loss.

  The reaction time for carrying out the hydroformylation reaction is usually 1 minute or longer, preferably 10 minutes or longer, more preferably 20 minutes or longer, 24 hours or shorter, preferably 10 hours or shorter, more preferably 5 hours or shorter. If the reaction time is too short, the reaction will not proceed sufficiently, and if it is too long, the boiling will proceed.

  The reactor in the above hydroformylation reaction may be a continuous type or a batch type, but it is necessary to seal the stirring tank 11 in order to satisfy the above reaction conditions. Since the sealing liquid of the mechanical seal 15 used for this sealing may enter the agitation tank 11, by using a liquid material that does not substantially reduce the catalytic activity of the catalyst, the reaction by the sealing liquid is performed. The influence of can be suppressed.

  By the production method according to the present invention, the aldehyde can be produced by satisfying the required pressure condition by sealing the stirring vessel while stabilizing the reaction without fear of a decrease in the catalytic activity due to the seal liquid.

In the apparatus shown in FIG. 3, an oxo gas B composed of carbon monoxide and hydrogen was supplied to the reactor 31, and a continuous hydroformylation reaction using propylene A as a raw material was performed. As the catalyst, a rhodium complex catalyst (RhH (CO) (P (C ₆ H ₅ ) ₃ ) ₃ ) and triphenylphosphine (TPP) dissolved in toluene was used, and the rhodium concentration in the catalyst solution was 270 mg / L, The TPP concentration was 24 wt%. The catalyst solution was sent together with the reaction product to the catalyst separation step 32 via the line 33, and circulated to the reactor 31 via the line 34 after separation from the product aldehyde C.
The reactor 31 was a complete mixing tank reactor having a volume of 1 m ³ with a heat removal coil and a stirrer, and the liquid level in the reactor was kept at 80% of the total volume.
Using this apparatus, the raw material propylene 65 kg / h was continuously hydroformylated. Oxo gas (H ₂ /CO=1.01) was fed to keep the pressure inside the reactor at 1.75 MPaG. The reaction temperature was constant at 100 ° C.
2-ethyl-hexanol was used as the sealing liquid for the mechanical seal, and the sealing liquid leaked continuously through the sliding portion with the stirrer shaft, and the leaking amount of the sealing liquid into the reactor averaged 80 mL / day. Met.
The activity of the catalyst solution after 6 months of operation with this apparatus was the same as that at the start of operation.

Schematic diagram of an example of a reactor with a stirrer in this invention Enlarged view of the mechanical seal of the reactor of FIG. Diagram of an example of a continuous hydroformylation reaction process

Explanation of symbols

11 Stirring tank 12 Motor 13 Stirring blade 14 Shaft 15 Mechanical seal 21 Seal piece 22 Seal liquid space 23 Seal liquid supply port 31 Reactor 32 Catalyst separation steps 33 and 34 Pipe line A Propylene B Oxogas C Formed aldehyde

Claims (2)

When performing a hydroformylation reaction using a stirred reactor, as a sealing liquid of the mechanical seal of the agitator, with substantially no decrease liquid material the catalytic activity of the catalyst used in the hydroformylation reaction, the liquid product is A method for producing an aldehyde, which is an alcohol obtained by hydrogenating a product aldehyde, or an alcohol obtained by hydrogenating a dimerized product aldehyde . The method for producing an aldehyde according to claim 1, wherein the liquid is a substance separable from the product aldehyde.

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