JPS5822132B2 - Olefin hydroformylation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for hydroformylating olefins.

Specifically, the present invention relates to a hydroformylation process containing a Group (I) noble metal-triarylphosphine complex catalyst obtained in a hydroformylation reaction of an olefin, a free triarylphosphine, a by-product triarylphosphine oxide, a generated aldehyde, and a reaction solvent. The present invention relates to a hydroformylation method in which triarylphosphines are selectively separated and recovered from a reaction product liquid and recycled to a hydroformylation reaction zone.

Group Ⅰ noble metal-triarylphosphine complex catalyst,
In particular, Group I noble metal-triphenylphosphine-based complex catalysts, or especially rhodium-triphenylphosphine-based chain catalysts, hydroformylate olefins to produce aldehydes with one more carbon number than the olefins. It is a well-known fact that it is advantageously used industrially as a so-called hydroformylation reaction catalyst.

Although it is more preferable for free triarylphosphine to coexist with this Group (I) noble metal-triarylphosphine complex catalyst, due to its high thermal stability, the generated aldehyde can be removed from the hydroformylation reaction product solution containing the complex catalyst. The catalyst liquid containing the complex catalyst is extracted by reactive distillation, for example, a method of stripping with an unreacted gas containing olefin, carbon oxide, and hydrogen, in a gaseous state along with the unreacted gas, and is separated. It has the great advantage that the hydroformylation reaction can be carried out continuously while remaining in the hydroformylation reaction zone.

Furthermore, according to this method, high-boiling condensation products of aldehydes as by-products can also be removed at the same time (Japanese Patent Laid-Open No. 52-125103).
).

According to this method, the group (I) noble metal-triarylphosphine complex catalyst has the great advantage that it can be left in the reaction zone and used continuously.
The problems that arise, such as the following, remain to be solved equally by those skilled in the art in carrying out hydroformylation reactions using the catalyst system.

That is, in industrial processes, by continuously using a catalyst liquid containing a group (I) noble metal-triarylphosphine complex catalyst and free triarylphosphine, the catalyst liquid in the reaction zone contains Triarylphosphine oxyto, which is produced by oxidation of a portion of triarylphosphine, accumulates due to oxygen mixed in the water and oxygen mixed in during the operations of various steps.

When triarylphosphine oxide and the like accumulate in the catalyst liquid, the overall volume of the catalyst liquid increases by an amount equivalent to the accumulated volume, making it impossible to maintain operation in a reaction vessel of a specified capacity.

In particular, when triphenylphosphine is used as the triarylphosphine, triphenylphosphine oxyto generated by oxidation of triphenylphosphine accumulates, increasing the rate of formation of undesirable branched aldehydes, which impairs the reaction results. It is known to have an adverse effect (Japanese Unexamined Patent Publication No. 51-8207).

Next, there is the problem of catalyst activity deterioration due to continuous use of the catalyst liquid for a long period of time.

That is, as the reaction time progresses, catalysts deactivated by trace amounts of reaction inhibitors contained in the raw materials accumulate in the catalyst solution.
Since the catalytic activity gradually decreases relative to the initial catalytic activity of the catalyst liquid, it becomes difficult to maintain a predetermined reaction rate.

The above-mentioned problems of accumulation of triarylphosphine oxide and accumulation of deactivated catalyst can be solved by continuously or intermittently extracting a part of the catalyst liquid in the reaction zone that uniformly contains these substances from the reaction system. Active group II precious metals suitable for
This problem can be solved by supplying a triarylphosphine complex, a rhodium salt as a complex source, a free triarylphosphine, and, in some cases, a reaction solvent to the reaction zone.

According to this method, the concentration of each of the above-mentioned accumulations in the catalyst liquid in the reaction zone is determined by the amount of the catalyst liquid extracted and the amount of each accumulation.

A certain equilibrium concentration is maintained at which it is possible to operate the hydroformylation reactor stably.

The above equilibrium concentration is determined as an industrially required optimum point.

The catalyst liquid extracted from the reaction system (hereinafter referred to as waste catalyst liquid) contains useful and expensive triarylphosphines and Group III noble metals that form complexes with triarylphosphines. From an industrial perspective, it is extremely desirable to efficiently separate, recover, and reuse this.

Conventionally, various methods have been proposed for separating and recovering Group I noble metals from waste catalyst liquid.

For example, the adsorption method (Japanese Patent Publication No. 48-28273,
-7114 etc.), extraction method using strong acid (Special Publication No. 46-43)
219), combustion recovery method (Japanese Patent Application Laid-Open No. 5O-39690), etc. are known.

On the other hand, only two methods are known for separating and recovering triarylphosphine, particularly triphenylphosphine.

That is, extraction method using strong mineral acid (%Kokusho 46-43219)
and HCHO-strong mineral acid extraction method (West German 0LS250
2233).

Among these, in the extraction method using strong mineral acids, rhodium is extracted simultaneously with free triphenylphosphine.

Also, in the HCHO-strong mineral acid extraction method, free triphenylphosphine is extracted into the aqueous layer together with rhodium.

In these methods, triphenylphosphine is extracted into the aqueous phase as a salt and must be further neutralized with alkali to be recycled to the hydroformylation reaction zone to form the counterion 504-,cn. - etc. need to be removed.

At that time, C4S etc. are known to be poisonous substances for rhodium catalysts (JP-A-50-71610, JP-A-5
41805) and may cause corrosion of the reactor, so when triphenylphosphine recovered by these methods is recycled and reused, it is necessary to strictly remove these anions and repurify it before reusing it. It is necessary to use it.

The present inventors have conducted intensive studies on a method for selectively recovering triarylphosphines from waste catalyst liquid without using these catalyst poisoning substances and Cl-1SO- ions, which are corrosive substances in the reactor, and found that the hydroformylation reaction The triarylphosphine, triarylphosphine oxyto, and group (I) noble metal-triarylphosphine complex catalyst have an appropriate solubility difference necessary for selective separation of triarylphosphine with respect to high-boiling organic compounds produced as by-products. The present invention was completed based on this finding.

That is, an object of the present invention is to provide an industrially advantageous method for carrying out the hydroformylation reaction of olefins.
This purpose is to use a Group I noble metal-triarylphosphine complex as a catalyst in the hydroformylation reaction zone;
A hydroformylation method in which an olefin is reacted with carbon monoxide and hydrogen to produce an aldehyde in a catalyst solution containing excess triarylphosphine and a reaction solvent, and the produced aldehyde is separated and obtained by evaporation from the reaction zone, A part of the catalyst liquid is extracted from the reaction zone as a waste catalyst liquid, the waste catalyst liquid is subjected to a crystallization treatment, the crystallized triarylphosphine is separated and recovered from the waste catalyst mother liquor, and the recovered triarylphosphine is hydroformylated. This is easily accomplished by recycling to the reaction zone.

The present invention will be explained in more detail below.

In the present invention, in the presence of excess triarylphosphine,
Applicable when separating and recovering triarylphosphines in the waste catalyst liquid discharged from the reaction zone in the olefin hydroformylation reaction using a group noble metal-triarylphosphine complex catalyst and reusing it in the hydroformylation reaction zone. The olefins used as raw materials for the hydroformylation of olefins include hydrocarbons having one or more olefinic unsaturated bonds, especially linear ones,
Alternatively, a branched lower olefin is used.

Preferably ethylene, propylene, 1-butene, ■-
Linear α-olefins having two or more carbon atoms such as hexene are used, but 2-butene, 2-pentene, 2
- Internal olefins such as hexene are also used.

Furthermore, olefins having a vinylidene structure such as isobutyne can also be used.

The mixed gas of carbon monoxide and hydrogen supplied to the reactor is
It is usually called water gas or oxo gas, and its typical composition is H2/co=1/3 to 20 (molar ratio)
It is.

The group Ⅰ noble metal-triarylphosphine complex catalyst used in the hydroformylation reaction is a group Ⅰ noble metal compound such as hydride, halide, carboxylate, nitrate, sulfate, etc. and triarylphosphine. It can be easily prepared by a complex formation method.

This complex catalyst may be used by preparing a complex in advance from the above-mentioned group (I) noble metal compound and triarylphosphine and then introducing it into the reaction zone, or by introducing the group (I) noble metal compound and triarylphosphine into the reaction zone. A complex may be formed in the reaction zone by supplying phosphine.

As the triarylphosphine ligand, triphenylphosphine is most preferably used;
Triarylphosphines in which the phenyl group is substituted with a lower alkyl group such as a methyl group, such as tolylphosphine, tri-m-tolylphosphine, tricylylphosphine, tris(p-ethylphenyl)phosphine, and tris(
Triarylphosphines with substituents that are inert under the hydroformylation reaction conditions may also be used, such as triarylphosphines in which the phenyl group is substituted with an alkoxy group such as methoxy group, such as P-methoxyphenyl)phosphine. Vine.

Examples of Group III noble metal compounds used to prepare the complex include ruthenium compounds such as ruthenium trichloride and tetraaminoruthenium hydroxychloride; rhodium dicarbonyl chloride, rhodium nitrate, rhodium trichloride, rhodium acetate, Rhodium compounds such as rhodium sulfate; palladium compounds such as balajiram hydride, palladium chloride, palladium iodide, palladium nitrate, palladium cyanide, palladium acetate, palladium e-sulfate; osmium compounds such as osmium trichloride and chloroosmic acid; Iridium compounds such as iridium oxide, iridium tetrabromide, iridium trifluoride, iridium trichloride, and iridium carbonyl; platinum such as platinum acid, platinum iodide, sodium hexachloroplatinate, potassium trichlor(ethylene) diplatinate, etc. Examples include compounds.

As is well known to those skilled in the art, a tertiary phosphine, such as a triarylphosphine, is typically added to the reaction zone to increase the thermal stability of the complex catalyst and to increase the proportion of useful linear aldehydes in the aldehyde produced. However, the coexisting amount is several tens of times the molar ratio of the complex catalyst in the reaction zone.
This is a several hundred times excess amount.

As the reaction solvent, a high boiling point organic compound mainly consisting of a self-polymerized product or a condensate of the aldehyde produced is usually used.

In this case, at the start of the hydroformylation reaction,
It is also possible to use an organic solvent that is inert to the hydroformylation reaction and can be separated by distillation from the aldehyde produced, and as the reaction progresses, a high-boiling organic compound that is produced as a by-product in the reaction replaces the organic solvent.

The reaction conditions for the hydroformylation reaction are usually a reaction temperature of 50 -
The reaction pressure is arbitrarily selected within the range of 150°C and 1 to 100 atm.

In the method of the present invention, the hydroformylation reaction is carried out, as is well known, in a hydroformylation reactor containing a catalyst solution containing a group (I) noble metal-triarylphosphine complex catalyst, an excess of triarylphosphine, a reaction solvent, and optionally a generated aldehyde. The raw materials, olefin and oxo gas, are introduced into the reactor, and the reaction is carried out at a predetermined temperature and pressure.

The aldehyde produced in the reaction is evaporated from the reaction zone as a gaseous mixture with unreacted gas by stripping with unreacted gas containing unreacted olefin, carbon oxide, hydrogen, etc., and taken out from the reactor.

At the same time, high-boiling organic compounds produced as by-products also flow out of the reactor together with unreacted gas.

The amount of outflow of high-boiling point organic compounds will be calculated based on the total amount produced, taking into consideration the amount of high-boiling point organic compounds contained in and discharged from the catalyst liquid extracted from the reaction zone as waste catalyst liquid, as described below. It is preferable to do so.

If the amount of high-boiling organic compounds exiting with unreacted gases is too large, a portion of the effluent is recycled to the reaction zone in order to keep the catalyst liquid level constant.

By this operation, the amount of catalyst liquid in the hydroformylation reactor is maintained at a preset constant value.

The liquid component consisting mainly of the aldehyde produced in the gaseous mixture taken out from the reactor is separated from the unreacted gas by cooling and condensation. Most of it is recycled to the reactor, except for a small amount of purge to prevent this.

In addition, as mentioned above, a portion of the catalyst liquid in the hydroformylation reaction zone is continuously or intermittently drained out of the reaction zone to avoid accumulation of deactivated catalyst or, in some cases, by-product high-boiling organic compounds. The catalyst liquid is extracted as a catalyst liquid, and an amount of catalyst and triarylphosphine corresponding to the extracted amount is newly supplied to the reaction zone.

The method of the present invention is usually applied to the residual liquid after the generated aldehyde is separated from the waste catalyst liquid extracted from the reaction system.

However, when the waste catalyst solution contains a large amount of reaction solvent other than high-boiling organic compounds, a part of the reaction solvent is further removed from the waste catalyst solution by a known method such as distillation, and the triaryl in the solution is removed. It is advantageous to apply the method according to the invention after increasing the phosphine concentration.

Removal of the reaction solvent from the waste catalyst liquid is carried out by conventional distillation, for example, atmospheric or reduced pressure distillation, or sl-IJ piping using gas injection.

The waste catalyst liquid is subjected to crystallization treatment after separating the aldehyde or removing a portion of the reaction solvent.

The waste catalyst liquid to be subjected to the crystallization treatment contains a high-boiling point organic compound (hereinafter referred to as "high-boiling point by-product organic compound") produced as a by-product in the hydroformylation reaction.

The high boiling point by-product organic compound is produced by a secondary side reaction of aldehyde produced in the hydroformylation reaction.

For example, in the hydroformylation reaction of propylene, n-butyraldehyde and 1-butyraldehyde are produced, but these aldehyde products are highly reactive and per se can react in the absence of a catalyst and even at relatively low temperatures. Polymerization or condensation reactions occur slowly to produce high-boiling polycondensation products.

Examples of these high boiling point polymers or condensates include the following types of substances.

That is, aldol, which is a dimer which is a self-polymerized product of n-butyraldehyde, trimer (described later), and 2 which is a condensed dimer.
- Ethylhexenal, its hydrogenated product 2-ethylhexinal, 2-ethylhexanol, and other high-boiling point polymers and condensates.

Dimers and trimers, which are self-polymerized products, are produced from i-butyraldehyde in the same reaction as n-butyraldehyde.
Furthermore, dimers, trimers, and derivatives thereof, which are alternating polymerization products of i-butyraldehyde and n-butyraldehyde, are also produced.

The above-mentioned high-boiling by-product organic compounds are composed of high-boiling polymers, condensates, and other high-boiling substances of unknown structure. Among them, the following general formula ( The content of high-boiling trimer polymers of linear and branched aldehydes formed from the corresponding olefins having structures represented by I) and (II) is relatively higher than that of other high-boiling substances.

[In the formula, R1, R2tR3tR4, R, and R6 represent hydrogen or a straight chain or branched alkyl group having 1 to 6 carbon atoms.

] The content of high-boiling point polymers having the structures represented by the above general formulas (I) and (n) is as follows. 10 to 100% by weight of the remainder excluding phosphine oxide, usually 30 to 800 to 80% by weight.

The high boiling point by-product organic compound has a high solubility in the Group (I) noble metal-triarylphosphine complex catalyst and triarylphosphine oxide, and is a good solvent for these, but its solubility for triarylphosphine is low. Relatively small.

In particular, the solubility of triarylphosphine in high-boiling point polymers having structures represented by general formulas (I) and (n) is low.

The method of the present invention utilizes a complex catalyst for high-boiling point by-product organic compounds and the difference in solubility between triarylphosphine oxide and triarylphosphine to selectively remove triarylphosphines by crystallizing a waste catalyst liquid. The waste is separated and collected.

At this time, if desired, the waste catalyst liquid may be crystallized by further adding a known poor solvent for triarylphosphine such as methanol.

When the waste catalyst liquid is subjected to crystallization treatment, the concentration of triarylphosphine in the liquid is determined mainly from the ease of operation of crystallization treatment, but is preferably 1 to 60% by weight.

In addition, the concentrations of Group Ⅰ noble metal-triarylphosphine complex catalyst and triarylphosphine oxyto in the waste catalyst liquid are not particularly limited as long as they are soluble, but each is usually from 0.001 to 10 weight section and 0~
It is in the range of 50% by weight.

When carrying out the crystallization treatment, the content of the high boiling point by-product organic compound in the waste catalyst liquid must be present in a specific amount relative to the triarylphosphine.

Usually, the crystallization treatment is carried out at a ratio (weight ratio) of triarylphosphine and the high-boiling by-product organic compound in the range of 1:0.2 to i:ioo, preferably 1:0.6 to 1=99. be done.

If the triarylphosphine concentration in the waste catalyst liquid extracted from the hydroformylation reaction system is low and outside the above range, it is preferable to concentrate the waste catalyst liquid by vacuum distillation or the like and then perform crystallization treatment. .

In addition, if the concentration of the high-boiling by-product organic compound in the waste catalyst liquid is low and outside the above range, the high-boiling by-product organic compound may be added separately for crystallization treatment. The crystallization treatment uses a known crystallizer, and 1
Any method such as step crystallization or multistep crystallization can be suitably used.

The crystallization temperature is not particularly limited as long as the triarylphosphine to be crystallized and the spent catalyst mother liquor can be separated, but it is usually -78°C to 80°C, preferably -20°C to 50°C.
It is carried out in the range of 0°C.

Triarylphosphine crystallized by crystallization treatment is
It is separated and recovered from the spent catalyst mother liquor by ordinary filtration or centrifugation.

In the above-mentioned crystallization treatment and triarylphosphine separation and recovery treatment, triarylphosphines are easily oxidized to triarylphosphine oxyto in the presence of oxygen, so in order to prevent this, an inert gas such as nitrogen is used. Alternatively, it is preferable to carry out under an atmosphere of carbon dioxide or the like.

The recovered triarylphosphine can be reused after undergoing distillation or purification treatment such as base crystals, or by circulating the recovered triarylphosphine as it is to the hydroformylation reaction zone without any purification treatment. do.

Since the waste catalyst mother liquor after separating and recovering the triarylphosphine contains group (I) noble metals, these known catalyst metal recovery methods, such as methods of recovering catalyst metals by burning the waste catalyst liquid, etc. , to separate and recover Group II precious metals.

After the recovered Group II precious metals go through the necessary processing steps,
Reused as a catalyst for hydroformylation reactions.

As described above in detail, according to the present invention, a useful and expensive triarylphosphine can be obtained by simple processes such as distillation, crystallization treatment, and solid-liquid separation treatment from a high-boiling point by-product reaction product liquid produced by the hydroformylation reaction. can be selectively separated and recovered in high yield, and the recovered triarylphosphine is hydroformylated.

Since it can be reused in the reaction, the industrial value of the present invention is extremely large.

Furthermore, triarylphosphine oxide that accumulates in the reaction solution is a catalytic activity inhibitor that reduces the production rate of useful linear aldehydes. Since oxyto is selectively removed, the industrial value of the present invention is extremely large in this respect as well.

Furthermore, by combining the separation and recovery method for triarylphosphines according to the method of the present invention with the known separation and recovery method for group (I) noble metals, useful and expensive triarylphosphines and Group III noble metals can be separated and recovered in high yield and purity, and can be reused in the hydroformylation reaction.
The hydroformylation reaction of olefins can be carried out with industrial advantage.

Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded.

Example 1 [Separation and recovery of triphenylphosphine from waste catalyst liquid] Triphenylphosphine Ioo&, toluene as a solvent 0.751, and rhodium acetate as rhodium metal were added to an induction rotation type autoclave with a capacity of 31. ．．
Charge 15g, set the temperature to 120℃, and the pressure to 20kg/c.
yyt G, 50 g of propylene was introduced per hour from the gas blowing pipe, and at the same time, oxo gas with H2/C0 = 1 was introduced at a rate such that the liquid level in the autoclave was kept constant while adjusting with a control valve.

Unreacted gas was purged from the gas vent pipe, and a cooling pipe was provided at the end of the purge pipe to cool and collect the generated aldehyde, toluene, and trace amounts of high-boiling byproduct organic compounds that were distilled out together with the unreacted gas.

The reaction was completed after 500 hours, and the reaction solution in the autoclave was taken out.

The aldehyde and a portion of the high-boiling by-product organic compounds were removed by distillation from the reaction solution to obtain a bottom liquid having the composition shown in Table 1.

An internal volume of 3001 was equipped with a thermometer and a stirring device, and the inside was maintained in a nitrogen atmosphere.
Pour into a four-bottle flask and heat to 10°C with stirring.
and held for 60 minutes.

Thereafter, the tube was transferred to a centrifugation container equipped with a cooling jacket in a nitrogen stream, and heated to 300-500℃ while maintaining the internal temperature at 10℃.
The mixture was centrifuged for 30 minutes at a rotational speed of 0.00 rpm to separate and collect triphenylphosphine crystals.

The recovered triphenylphosphine crystals were 24 g, the recovery rate was 80%, the triphenylphosphine oxyto content in the crystals was 0.1 g, the rhodium complex content was 4.71n9 in terms of rhodium metal, and triphenylphosphine were selectively recovered.

In addition, triphenylphosphine in the centrifuged spent catalyst mother liquor was 6 g, and triphenylphosphine oxyto was 1.
8g, rhodium complex is 43.3m9 in terms of rhodium metal
Met.

Example 2 [Hydroformylation reaction of propylene using recovered and purified triphenylphosphine] Internal volume 200 m
Add 45ml of triene to A' electromagnetic stirring autoclave.
Purified product obtained by recrystallizing the triphenylphosphine recovered in Example 1 from a benzene-methanol system using a conventional method*16g
and rhodium acetate in terms of rhodium metal: 1.5 r11
After making 9 preparations and replacing the autoclave with nitrogen gas,
238 mmol of propylene was charged by distillation.

The temperature of the autoclave was raised to 120°C, and a mixed gas of carbon monoxide and hydrogen (oxo gas, H2/co = 1
(molar ratio) to increase the reaction pressure to 20 kp/cr.
The reaction was started at 120° C. while maintaining it at G.

In order to keep the pressure constant during the reaction, the autoclave and the oxo gas pressure accumulator were connected via an automatic pressure constant device to replenish the oxo gas consumed by the reaction.

The reaction was considered to have ended when no gas absorption was observed, and after the autoclave was cooled, residual propylene and butyraldehyde produced in the gas and liquid phases were analyzed by gas chromatography.

As a result, the reaction rate of propylene was 99.3%, and the selectivity to butyraldehyde was 99.0%.

The (normal form/iso form) ratio of the produced butyraldehyde was 3.5.

Also, from the decreasing curve of 4-oxo gas pressure in the pressure accumulator, the reaction rate constant (0th order) was found to be 1.21 (1/Hr
)Met.

*1 As a result of rhodium analysis, it was confirmed that substantially no rhodium complex was observed in the triphenylphosphine.

Reference Example 1 [Hydroformylation reaction of propylene using new triphenylphosphine that has no history of hydroformylation reaction] Instead of using the triphenylphosphine recovered and purified in Example 2, the same triphenylphosphine that was charged into the autoclave in Example 1 was used. The reaction was carried out under the same conditions as in Example 2 except that phenylphosphine was used.

As a result, the reaction rate of propylene was 99.2%, and the selectivity to butyraldehyde was 99.0%.

The (normal form/iso form) ratio of the butyraldehyde produced was 3.5.

Further, the reaction rate constant was 1.20 (1/Hr).

Example 3 [Hydroformylation reaction of taflopyrene using recovered and unpurified triphenylphosphine] Example 2 except that the triphenylphosphine containing a trace amount of rhodium complex recovered in Example 1 was used as it was without purification treatment. The reaction was carried out under exactly the same conditions.

As a result, the reaction rate of propylene was 99.2%, and the selectivity to butyraldehyde was 99.0%.

The (normal form/iso form) ratio of the produced butyraldehyde is 3.5, and the reaction rate constant (first order) is 2.12.
(1/Hr).

Example 4 [Correction experiment for determining the reaction activity of the rhodium complex remaining in the recovered triphenylphosphine] The reaction was carried out under exactly the same conditions as in Example 3 except that rhodium acetate was not added.

As a result, the reaction rate of pyrene was 99.0%, and the selectivity of butyraldehyde was 99.0%.

The (normal form/iso form) ratio of the butyraldehyde produced was 3.5.

The reaction rate of the remaining rhodium complex was 0.90 (1/Hr) in terms of reaction rate constant (first order).

Table 2 summarizes the results of Examples 2 to 4 and Reference Example 1.

Table 2 Activity of rhodium complex catalyst with added Rh metal equivalent of 1.5η From the above results, the desired reaction results and reaction can be achieved even if the crystallized and recovered triphenylphosphine is recycled as it is to the hydroformylation reaction system. It was confirmed that speed was achieved.

Of course, it is clear that there is no harm in performing purification treatment.

Claims (1)

[Claims] 1. In a hydroformylation reaction zone, an olefin is treated with carbon monoxide and hydrogen in a catalyst solution containing a Group (I) noble metal-triarylphosphine complex as a catalyst, an excess of triarylphosphine, and a reaction solvent. In a hydroformylation method in which an aldehyde is produced by reacting with the reaction zone, and the generated aldehyde is separated and obtained by evaporation from the reaction zone, a part of the catalyst liquid is extracted from the reaction zone as a waste catalyst liquid, and the waste catalyst is crystallized. Olefin hydroformylation method 02, characterized in that the triarylphosphine is separated and recovered from the spent catalyst mother liquor, and the recovered triarylphosphine is recycled to the reaction zone. A hydroformylation method characterized in that the Group (I) noble metal is rhodium. 3. The method for hydroformylating an olefin according to claim 1 or 2, wherein the triarylphosphine is triphenylphosphine. 4. In the method for hydroformylating an olefin according to any one of claims 1 to 3, the aldehyde produced is stripped from the reaction zone with an unreacted gas containing olefin, carbon oxide, and hydrogen. A method characterized in that the method is characterized in that the method is characterized in that it is obtained separately. 5. In the method for hydroformylating olefins according to any one of claims 1 to 4, the concentration of doria IJ-ruphosphine in the waste catalyst liquid to be subjected to crystallization treatment is 1 to 60% by weight. A method characterized by: 6. A method for hydroformylating an olefin according to any one of claims 1 to 5, characterized in that the crystallization temperature is in the range of 178 to 80°C. A method for hydroformylating olefins according to any one of claims 1 to 6, characterized in that the recovered triarylphosphine is purified and then recycled to the hydroformylation reaction zone.