JPS6120345B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for regenerating and recovering a cobalt carbonyl catalyst from an oxo reaction product. A cobalt compound is generally used as a catalyst in the oxo reaction, in which an olefinic unsaturated compound is reacted with a mixed gas of hydrogen and carbon monoxide under high pressure to produce an aldehyde with one more carbon number than the raw material olefinic unsaturated compound. . The cobalt compound used as a catalyst is added to the reaction system in various forms.In a reaction system in which a modifier such as phosphine is not added, cobalt exists in the form of dicobalt octacarbonyl and/or cobalt hydrocarbonyl, and the cobalt compound is added to the reaction system in various forms. It is said that it acts as a Industrially, when recovering a cobalt carbonyl catalyst from an oxo reaction product, the cobalt carbonyl catalyst is generally separated and recovered as an aqueous solution of cobalt ions or an aqueous solution of cobalt carbonyl ions. However, these recovery methods use large amounts of acids and alkalis, which pose problems such as corrosion of equipment and treatment of waste water, and are not preferable in terms of pollution. The present invention relates to a method for regenerating and recovering a cobalt carbonyl catalyst from an oxo reaction product, and is essentially a closed and non-polluting recovery and regeneration method that does not use acids or alkalis and does not generate large amounts of waste water. The method of the present invention involves treating the oxo reaction product under mild conditions with an organic solvent (hereinafter referred to as an extractant) that does not dissolve in the oxo reaction product and acts as a Lewis base. After transferring the cobalt carbonyl catalyst into the extractant, the extractant phase is treated with a mixed gas of hydrogen and carbon monoxide or carbon monoxide gas in the presence or absence of an organic solvent that is not mutually soluble with the extractant. This method regenerates and recovers dicobalt octacarbonyl and/or cobalt hydrocarbonyl. The method of the present invention will be explained in more detail below. The mechanism of action of the extractant in the present invention is probably as shown in the following formula, in which a cobalt carbonyl compound () is produced and this compound is dissolved in the extractant. 3Co ₂ (CO) ₈ +2.X.Solv→2 [Co(Solv) _X ]
[Co(CO) ₄ ] ₂ +8CO [] etc. Specifically, polyhydric alcohols such as ethylene glycol, propylene glycol, 1,4-butanediol, glycerin, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol, 200-600, Polypropylene glycol, ether alcohols such as 400 to 2000, nitriles such as adiponitrile, nitro compounds such as nitromethane, amides such as formamide, sulfoxides such as tetramethylsulfolane, amines such as triethanolamine, etc. are used alone or in mixtures. Also, a small amount of water may be added to the water-soluble extractant. In the present invention, suitable conditions for treating the oxo reaction product with an extractant are normal pressure and a temperature of 10 to 100°C, and pressure reaction is also possible. It is sufficient to use the extractant in an amount (weight) of about 1 to 1/10 of the oxo reaction product. When the extractant treatment is carried out in this manner, the cobalt carbonyl catalyst contained in the oxo reaction product changes into a cobalt carbonyl compound () and easily migrates into the extractant. After extraction, if the mixture is allowed to stand still, two layers, the extractant phase and the oxo reaction product, are formed and the two can be easily separated. The oxo reaction product from which the extractant phase has been separated in this way is further treated with an extractant in a multi-stage operation, so that only a very small amount of cobalt carbonyl catalyst is present in the oxo reaction product, and the oxo reaction product is separated and hydrogenated. Purification is extremely easy to perform. On the other hand, isolated cobalt carbonyl compound ()
The cobalt carbonyl compound () is extracted by treating the extractant phase containing the extractant with a hydrogen and carbon monoxide mixed gas or carbon monoxide gas in the presence or absence of an organic solvent (hereinafter referred to as solvent) that does not dissolve in the extractant and the cobalt carbonyl compound ().
is recovered from the extractant as dicobalt octacarbonyl and/or cobalt hydrocarbonyl. The solvent is usually selected from raw olefinic compounds such as hexene, saturated or unsaturated hydrocarbons such as hexane, aliphatic hydrocarbons, aromatic hydrocarbons such as benzene, toluene, etc., and is used in an amount of about 1 to 1/50 of the extractant (by weight). ) is sufficient. For treatment with hydrogen and carbon monoxide mixed gas or carbon monoxide gas, a solvent is added to an extractant containing a cobalt carbonyl compound () and the pressure is 10°C in the presence of the above gas.
When treated at ~200 Kg/cm ² G and a temperature of 10 to 200° C., the cobalt carbonyl compound ( ) decomposes into dicobalt octacarbonyl and/or cobalt hydrocarbonyl, which migrates into the solvent. A suitable mixing ratio of hydrogen gas and carbon monoxide gas is 1/10 to 10/1. Alternatively, only the extractant containing the cobalt carbonyl compound (2) may be treated with a mixed gas of hydrogen and carbon monoxide without adding a solvent, and the generated cobalt hydrogalvonyl may be introduced into the solvent and absorbed. The above treatment method can further improve the recovery rate as dicobalt octacarbonyl and/or cobalt hydrocarbonyl by performing multistage operations. Furthermore, when a solvent is added to the extractant containing the separated cobalt carbonyl compound () and treated with air or oxygen gas at normal pressure and temperature of 10 to 80°C, the cobalt carbonyl compound () decomposes and dicobalt octacarbonyl is regenerated into the solvent. It will be collected. However, the recovery rate is lower than that of mixed gas of hydrogen and carbon monoxide or carbon monoxide gas treatment. Further, treatment with a mixed gas of hydrogen and carbon monoxide or a combination of carbon monoxide gas treatment and air or oxygen gas treatment is also possible. Dicobalt octacarbonyl and dicobalt hydrocarbonyl recovered through such treatment can be directly recycled and reused in the oxo reaction system in the form of absorption in a solvent. Next, successive embodiments of the present invention will be explained in more detail with reference to FIGS. 1 and 2. Regarding Figure 1, the raw material olefinic compound is supplied from pipe 1, and the mixed gas of hydrogen and carbon monoxide is supplied from pipe 2.
Then, a cobalt carbonyl catalyst dissolved in a solvent is introduced into the oxo reaction tower 4 through the pipe 3 to carry out the oxo reaction. The oxo reaction product and the extractant are introduced into the multi-stage extractant column 7 via pipes 5 and 6, respectively. Here, the oxo reaction product and the extractant are brought into sufficient contact with each other, and the cobalt carbonyl catalyst in the oxo reaction product is converted into a cobalt carbonyl compound (), which is transferred into the extractant and introduced into the first separation tank 9 via the pipe 8.
In this separation tank, the oxo reaction product and the extractant phase containing the cobalt carbonyl compound are separated into two layers,
The oxo reaction product is taken out from the top, and the extractant phase is taken out from the bottom. The extractant phase and the solvent are introduced into the multistage catalyst regeneration tower 13 through pipes 10 and 11, respectively. Further, by introducing a mixed gas of hydrogen and carbon monoxide or carbon monoxide gas into the pipe 12, the cobalt carbonyl compound (2) is decomposed. The treated liquid is sent to the second separation tank 15 through the pipe 14, and is separated into two layers: a solvent phase containing dicobalt octacarbonyl and/or cobalt hydrocarbonyl, and an extractant phase. The extractant phase is reintroduced to the multistage extractant treatment tower 7 through the pipe 6 and used. On the other hand, the solvent phase containing dicobalt octacarbonyl and cobalt hydrocarbonyl is introduced from the second separation tank 15 into the oxo reaction tower 4 via the pipe 3. On the other hand, the oxo compound separated in the first separation tank 9 is sent via a pipe 16 to a treatment column for hydrodistillation, purification, etc. Note that 17 and 18 indicate off-gas piping. In Fig. 2, the operation up to the separation tank 9 is the same as in Fig. 1, but in the multistage catalyst regeneration tower 12, a mixed gas of hydrogen and carbon monoxide is blown into the multistage catalyst regeneration tower 12 without using a solvent. Disassemble.
The generated gas is introduced into the catalyst absorption tank 15 via the pipe 13. Also, a solvent is introduced through the pipe 14 to absorb the generated gas. This cobalt hydrocarbonyl-containing solvent is sent to the oxo reaction tower 4 from the pipe 3 in the same manner as shown in FIG. 1 and is reused. On the other hand, catalyst regeneration tower 12
The treated extractant is introduced into the multi-stage extractant treatment tank 7 and reused in the same manner as shown in FIG. Note that 17 and 18 indicate off-gas piping. When the method of the present invention is used, the catalyst is regenerated and recovered without using acids or alkalis, and there is no problem with waste water, which is industrially advantageous. Next, an example will be described in more detail. In this example, catalyst regeneration and separation was carried out in an apparatus corresponding to one stage. When using a multi-stage catalyst regeneration tower, the transfer of the catalyst to the solvent is The solvent containing the catalyst can be recycled to the oxo reaction column and reused. Example 1 An oxo reaction product obtained by reacting decene-1 with a mixed gas of hydrogen and carbon monoxide using a dicobalt octacarbonyl catalyst (cobalt concentration 1.85 g/
Kg) Add 150g of ethylene glycol to 150g and temperature
After stirring at 40°C for 15 minutes and standing for 15 minutes, the ethylene glycol phase is separated and removed. The cobalt concentration of this oxo reaction product was 0.11 g/Kg, and the cobalt carbonyl catalyst removal rate was 94%. Next, 100g of ethylene glycol containing cobalt carbonyl compound () (cobalt concentration 1.73g/Kg), n-decane
Pour 100g into a 300ml stainless steel autoclave with vertical stirring at a pressure of 150Kg/ ^cm2G and a temperature of 160℃ _H2 /
Treated for 1 hour under CO = 2 conditions, left to stand for 15 minutes, then n-
Separate and remove the decane phase. The cobalt concentration in this n-decane phase was 1.04 g/Kg, and the cobalt carbonyl catalyst recovery rate was 60%. Example 2 100 g of ethylene glycol containing cobalt carbonyl compound () obtained in the same manner as in Example 1
(cobalt concentration 1.73g/Kg), n-decane 100g
Pour into a 300ml stainless steel autoclave with vertical stirring, pressure 150Kg/cm ² G, reaction temperature 160℃H ₂ /CO
= 2 for 3 hours, and after standing for 15 minutes, the cobalt concentration in the n-decane phase was 1.35 g/Kg, and the cobalt carbonyl catalyst recovery rate was 78%. It can be seen that the cobalt carbonyl catalyst recovery rate is improved by allowing sufficient residence time in the reactor. That is, it is estimated that the catalyst can be almost completely recovered by maintaining a sufficient residence time in the multistage catalyst regeneration tower. Example 3 150 g of various extractants were added to 150 g of the oxo reaction product of Example 1, stirred for 15 minutes at a specified temperature, left to stand for 15 minutes, and then the extractant phase was separated and removed. The cobalt carbonyl catalyst removal rate was as shown in the table.

[Table] Example 4 Add 200 g of ethylene glycol to 200 g of the oxo reaction product of Example 1, stir at 60°C for 15 minutes, leave to stand for 15 minutes, and then separate and remove the ethylene glycol phase. The removal rate of the cobalt carbonyl catalyst from the oxo reaction product was 95%. 150g of this cobalt carbonyl compound ()-containing ethylene glycol (cobalt concentration 1.76g/Kg) was charged into a 300ml stainless steel autoclave with vertical stirring, and the pressure was 150Kg/Kg.
cm ² G. The cobalt concentration in the decene-1 phase was 0.70 g/Kg and the cobalt carbonyl catalyst was treated for 1 hour at a temperature of 160°C and H ₂ /CO = 1, and the generated gas was absorbed into decene-1,150 g. The recovery rate was 40%. Example 5 Polyethylene glycol containing 3% ethylene glycol was added to 150 g of the oxo reaction product of Example 1.
Add 200 and 150 g, stir for 15 minutes at a temperature of 40°C, and after standing still for 15 minutes, separate and remove the polyethylene glycol 200 phase containing 3% ethylene glycol. The removal rate of the cobalt carbonyl catalyst from the oxo reaction product was 93%. 100 g of polyethylene glycol containing 3% ethylene glycol containing this cobalt carbonyl compound I (cobalt concentration
1.72g/Kg) Decene - 1,100g was placed in a 500ml stainless steel autoclave with vertical stirring and the pressure was 150.
Kg/cm ² G.1 with carbon monoxide gas at a temperature of 160℃
After treatment for 15 minutes, the decene-1 phase was separated and removed. The cobalt concentration of this decene-1 phase is 0.89g/Kg
The cobalt carbonyl catalyst recovery rate was 52%.

[Brief explanation of the drawing]

1 and 2 show flow sheets for carrying out the present invention, and the numbers written in the drawings represent piping equipment, etc. In Figure 1, 1, 2, 3, 5, 6, 8, 1
0, 11, 12, 14, 16, 17, 18 are piping, 4 is an oxo reaction tower, 7 is a multistage extractant treatment tower,
Reference numeral 9 indicates a first separation tank, 13 a multistage catalyst regeneration tower, and 15 a second separation tank. In Figure 2, 1,
2, 3, 5, 6, 8, 10, 11, 13, 14,
16, 17, 18 are piping, 4 is oxo reaction tower,
7 is a multistage extractant treatment tower, 9 is a separation tank, 12 is a multistage catalyst regeneration tower, and 15 is a catalyst absorption tank.

Claims (1)

[Claims] 1. After the cobalt carbonyl catalyst in the oxo reaction product is transferred as a cobalt carbonyl compound () into an extractant that is not mutually soluble with the oxo reaction product and acts as a Lewis base, The extractant phase is treated with a mixed gas of hydrogen and carbon monoxide or carbon monoxide gas in the presence or absence of an insoluble solvent, and the cobalt carbonyl compound () in the extractant phase is converted into dicobalt octacarbonyl and/or cobalt hydrocarbon. A method for regenerating and recovering a cobalt carbonyl catalyst, the method comprising recycling and recovering the cobalt carbonyl catalyst.