KR100969474B1 - Method for recovering rhodium catalyst from products obtained by hydroformylation reaction - Google Patents

Abstract

The present invention relates to a method for recovering a rhodium catalyst, the method comprising recovering a solid comprising a rhodium catalyst and triphenylphosphine oxide with an organic solvent. The present invention can be applied to a method for recovering a rhodium catalyst from a product of a hydroformylation reaction. The method for recovering a rhodium catalyst according to the present invention has the advantage of efficiently recovering a rhodium catalyst from a solid including a rhodium catalyst and triphenylphosphine oxide, and in particular, triphenylphosphine jade from the product of the hydroformylation reaction. By minimizing the loss of the rhodium catalyst that is removed together in the process of removing the seed (TPPO), there is an advantage that the rhodium catalyst can be efficiently recovered.

Hydroformylation, oxo, rhodium catalyst, triphenylphosphine, ligand, triphenylphosphine oxide, recrystallization, washing, organic solvent, butylaldehyde

Description

Rhodium catalyst recovery from hydroformylation reaction product {METHOD FOR RECOVERING RHODIUM CATALYST FROM PRODUCTS OBTAINED BY HYDROFORMYLATION REACTION}

1 is a process diagram of a hydroformylation reaction of an embodiment to which the present invention is applied

≪ Description of reference numerals &

1: reaction raw material supply line

2: first reactor

3: second reactor

4: top of evaporator

5: bottom of evaporator

6: product transfer line

7: Unreacted Raw Material Recovery Line

8: Sedimentation, Filtration and Washing Equipment

9: catalyst recovery line

The present invention relates to a method for recovering a rhodium catalyst, and more particularly, to a method for efficiently recovering a rhodium catalyst from a solid comprising a rhodium catalyst and triphenylphosphine oxide. The present invention can be applied to the method for recovering rhodium catalyst from the product of the hydroformylation reaction.

Hydroformylation, also known as OXO reaction, is a linear-, normal-, carbon-based increase in the presence of a metal catalyst and a ligand of olefins and synthetic gases (CO / H2). ) Or branched (iso-) aldehyde (aldehyde). The produced aldehyde may be oxidized or reduced to be transformed into an aldehyde derivative acid and alcohol, or may be transformed to various acids and alcohols containing a long alkyl group through oxidation or reduction after condensation reaction such as aldol, and the like. May be used as a raw material for various solvents, additives, plasticizers and the like.

As a catalyst for the hydroformylation reaction, acetylacetonatodicarbonyldium (Rh (AcAc) (CO) ₂ ), acetylacetonatocarbonyltriphenylphosphindium (Rh (AcAc) (CO) (TPP)), Hirididocarbonyltristriphenylphosphinedium (HRh (CO) (TPP) ₃ ) and the like are mainly used, and these catalysts are commercially available. For example, reaction of propene as a raw material As a catalyst, tetra (carbonyl) cobalt sodium (NaCo (CO) ₄ ) from BASF, hydridotricarbonyltributylphosphinecobalt (HCo (CO) ₃ PBu ₃ ) from Shell, hydridocarbonyltritree from UCC, etc. Phenylphosphinedium (HRh (CO) (TPP) ₃ ), rhodium / TPPTS from Ruhrchemie-Rhone-Poulence can be purchased. On the other hand, Rh (AcAc) (CO) ₂ and Rh (AcAc) (CO) (TPP) are both catalyst active species under the reaction conditions in which synthetic gas and ligand triphenylphosphine (TPP) are present. Lidocarbonyltristriphenylphosphinedium (HRh (CO) (TPP) ₃ ) is known to be converted.

The core metals of the hydroformylation catalyst are iridium (Ir), ruthenium (Ru), osmium (Os), platinum (Pt), palladium (Pd), and iron (Fe) in addition to cobalt (Co) and rhodium (Rh). Ni, Ni, etc. can be applied, but the catalytic activity of the metal is known in the order of Rh »Co> Ir, Ru> Os> Pt> Pd> Fe> Ni, so rhodium and cobalt are commercialized in the actual process. And research and development.

In general, a catalyst such as rhodium is used together with a ligand, and as the ligand, phosphine (PR ₃ , R = C ₆ H ₅ , nC ₄ H ₉ ), phosphine oxide, O = P (C ₆ H ₅ ) ₃ ), phosphite, amine, amide, isonitrile, etc., but triphenylphosphine (TPP) The best. However, triphenylphosphine is easily combined with oxygen molecules and oxidized to triphenylphosphine oxide (TPPO), and triphenylphosphine oxide is an unnecessary substance at various stages of the hydroformylation reaction, which reduces productivity and process efficiency. Cause. Therefore, a method for removing triphenylphosphine oxide was studied. As a result of the recrystallization method, triphenylphosphine oxide (TPPO) was effectively removed. However, rhodium, which is an important noble metal catalyst, is lost in the process, which has a fatal effect on the stability and productivity of the reaction and the efficiency of the process, as well as an excessive catalyst cost to compensate for it. Therefore, minimizing the loss of the rhodium catalyst in the process of removing triphenylphosphine oxide from the product of the hydroformylation reaction is an important task, which ultimately is a solid comprising a rhodium catalyst and triphenylphosphine oxide The present invention relates to a method for efficiently recovering a rhodium catalyst from.

It is therefore an object of the present invention to provide a method for efficiently recovering a rhodium catalyst from a solid comprising a rhodium catalyst and triphenylphosphine oxide.

Another object of the present invention is to provide a method for recovering a rhodium catalyst from the product of the hydroformylation reaction, which minimizes the loss of the rhodium catalyst which is removed together in the process of removing triphenylphosphine oxide from the product of the hydroformylation reaction. will be.

In order to achieve the above object, the present invention

It provides a method for recovering a rhodium catalyst comprising the step of washing a solid comprising a rhodium catalyst and triphenylphosphine oxide with an organic solvent.

The present invention further comprises the steps of distilling the product of the hydroformylation reaction to separate an aldehyde compound (iii) and a catalyst solution (ii) comprising a) a rhodium catalyst and b) triphenyl phosphine oxide;

Recrystallization of the separated catalyst solution to precipitate and precipitate triphenylphosphine oxide; And

Washing the precipitate comprising the filtered triphenylphosphine oxide with an organic solvent;

It provides a method for recovering the rhodium catalyst from the product of the hydroformylation reaction comprising a.

 Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

1 is a process chart of a hydroformylation reaction of an embodiment to which the present invention is applied.

Solids comprising a rhodium catalyst and triphenylphosphine oxide may be solids comprising a rhodium catalyst and triphenylphosphine oxide, obtained by distillation, recrystallization, precipitation and filtration of the product of the hydroformylation reaction.

Hereinafter, the present invention will be described in detail through a process of hydroformylation reaction.

The product of the hydroformylation reaction according to the present invention is produced from a conventional hydroformylation reaction, and the hydroformylation reaction, as shown in FIG. 1, first through the reaction raw material supply line (1) It starts with entering the first reactor 2. The introduced reactant stays in the first reactor 2 for a predetermined time to undergo a hydroformylation reaction. The reactant flowing out of the first reactor 2 may be introduced into the second reactor 3 as necessary for the remaining hydroformylation reaction.

The reaction raw material is a raw material of a conventional hydroformylation reaction, and includes olefin, syngas (carbon dioxide / hydrogen), rhodium catalyst, triphenylphosphine as a ligand, reaction solvent and the like.

The olefin can be used without limitation the olefin used in the hydroformylation reaction, for example, a carbon compound containing a double bond at the end and / or stop of the branch, ethylene, propylene, butylene, pentene, hexene, heptene, Alkene compounds, such as an oxene, can be used.

Syngas is a synthesis gas used in the hydroformylation reaction and is a mixed gas of carbon monoxide / hydrogen.

The rhodium catalyst of the present invention can be used as a rhodium / triphenylphosphine catalyst system in which triphenylphosphine is complexed, and such a rhodium catalyst system is acetylacetonatocarbonyltriphenylphosphinedium (Rh (AcAc) (CO ) (TPP)), hydridocarbonyltristriphenylphosphinedium (HRh (CO) (TPP) ₃ ), and the like, and may be used with catalysts commonly used in other hydroformylation reactions.

The reaction solvent can be used without limitation as long as it dissolves the reaction solvent and catalyst complex which are usually used in the hydroformylation reaction and does not adversely affect the reaction. Non-limiting examples of the reaction solvent include aldehydes produced by ester hydroformylation reactions such as aromatic hydrocarbon butanol such as aliphatic saturated carbon hydrogen toluene such as hexane, octane and cyclohexane and alcohol ether dioctyl phthalate such as forylethylene glycol. Or dimers thereof and mixtures thereof.

The temperature of the hydroformylation reaction is a temperature of a typical hydroformylation reaction, for example, 15 to 300 ° C, preferably 40 to 200 ° C, more preferably 40 to 100 ° C in view of the stability of the catalyst. The reaction pressure is the pressure of a conventional hydroformylation reaction, for example, 1 to 300 atm, preferably 40 to 80 atm, more preferably about 20 bar.

The products of the hydroformylation reaction according to the present invention may include the target aldehyde, unreacted olefin, syngas, reaction solvent, rhodium catalyst, triphenylphosphine as a ligand, triphenylphosphine oxide, and other side reactants. Can be.

Next, as shown in FIG. 1, the reactant flowing out of the second reactor 3 flows into the evaporators 4 and 5 to distill the product of the hydroformylation reaction according to the present invention to form an aldehyde compound and rhodium. Separating the catalyst solution comprising the catalyst and triphenyl phosphine oxide is carried out. This step can be carried out by a conventional method of distilling the product of the hydroformylation reaction to separate the aldehyde compound and the catalyst solution. This step may be carried out in a continuous process or a batch process as shown in FIG. 1.

When the product of the hydroformylation reaction is distilled off, the low boiling point compound flows out of the evaporator through the upper end 4 of the evaporator as a gaseous state, and the high boiling point compound is in the form of liquid, solid, etc. It flows through. In general, the high boiling point compound is a target substance, such as an aldehyde compound, a synthesis gas, and the like, which is separated again through a separate operation, and the aldehyde compound is obtained as a final target through the product transfer line (6), and other low boiling point compounds such as synthesis gas. Is recycled to the reactors 2 and 3 via an unreacted raw material recovery line 7.

The high boiling point compound includes an unreacted olefin (high boiling point olefin), a reaction solvent (high boiling point reactant), a rhodium catalyst, a triphenylphosphine ligand, a triphenylphosphine oxide, and other side reactants. This is called a catalyst solution.

Next, the catalyst solution flowing out from the lower end 5 of the distillation column flows into the precipitation, filtration and washing apparatus 8. As shown in FIG. 1, the present invention can be carried out by adding a precipitation, filtration and washing apparatus 8 to a conventional hydroformylation reaction process in the prior art, and the precipitation, filtration and washing apparatus 8 is an evaporator. The catalyst solution discharged from the lower end 5 is installed in the middle of the catalyst recovery line 9 which is recovered to the first reactor 2, and then exits in the direction of the catalyst solution line coming from the evaporator lower end 5 and in the direction of the first reactor. Catalyst solution lines can be connected. The precipitation, filtration and washing apparatus 8 may be a jacketed bath, the line into which the washing solvent, for example butylaldehyde (BAL) which is the product of the hydroformylation reaction, is introduced and the line which recycles it. It may be included (not shown).

The catalyst solution flowing out of the evaporator bottom 5 passes through the catalyst recovery line 9 and, as shown in FIG. 1, only a part of the catalyst solution can flow into the precipitation, filtration and washing apparatus 8, as a whole. May be introduced.

Recrystallizing the separated catalyst solution according to the present invention carried out in the precipitation, filtration and washing apparatus 8 to precipitate triphenylphosphine oxide and filter it may be carried out in a batch process or in a continuous process.

The recrystallization temperature (precipitation temperature) of the precipitation and filtration steps is, for example, 0 to 60 ° C. at normal pressure.

Next, about the precipitate containing triphenylphosphine oxide in the precipitation, filtration and washing apparatus 8, the precipitate containing the filtered triphenylphosphine oxide according to the present invention is washed with an organic solvent and included in the precipitate. Recovering the rhodium catalyst is carried out. This step can be carried out in a continuous process or a batch process.

Recrystallizing the catalyst solution to precipitate and filter triphenylphosphine oxide (TPPO) is basically a step for selectively removing only unnecessary high boiling point materials such as triphenylphosphine oxide (TPPO) in the catalyst solution. According to the ICP analysis, it is found that rhodium, which is a catalyst metal, is detected in the components of the crystal mass precipitated (precipitated) by recrystallization. One of the most expensive noble metals, if rhodium, the most important component of the hydroformylation catalyst solution, is removed together with triphenylphosphine oxide (TPPO) in the recrystallization process, it can cause a serious problem that the hydroformylation reaction does not proceed. .

Therefore, this step is to minimize the loss of the rhodium catalyst by washing the precipitate containing the filtered triphenylphosphine oxide with an organic solvent to recover the rhodium catalyst contained in the precipitate and sent back to the catalyst solution. By washing the precipitate containing triphenylphosphine oxide by the organic solvent by this washing step it is possible to efficiently recover the rhodium catalyst contained in the precipitate. Although triphenylphosphine oxide dissolved in the precipitate by the organic solvent is dissolved together with the organic solvent, the removal rate of triphenylphosphine oxide is reduced, but the ratio of the loss rate of the rhodium catalyst to the removal rate of triphenylphosphine oxide is decreased. . Increasing the amount of organic solvent used further reduces the loss ratio of the rhodium catalyst to the removal rate of triphenylphosphine oxide, making the process more efficient. This tendency is that when the process is carried out in a rotational cycle by repeating a predetermined amount of organic solvent (washing solvent) two or more times, the ratio of the loss rate of the rhodium catalyst to the removal rate of triphenylphosphine oxide is further reduced, and thus the rhodium catalyst Most can be recovered.

Organic solvents (washing solvents) that can be used in this step include aldehyde acetone such as propane aldehyde, butyl aldehyde, baler aldehyde, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, and ketone benzene, toluene and xylene, such as cyclohexanone. Halogenated aromatic compounds comprising an aromatic compound orthodichlorobenzene paraffinic hydrocarbon compounds such as halogenated paraffin compounds heptane and ether mixtures thereof including ether methylene chloride such as tetrahydrofuran, dimethoxyethane and dioxane and mixtures thereof It is preferable to use a solvent (reaction solvent) of the catalyst solution, more preferably butyl aldehyde, in view of efficiency of process operation and the like.

The temperature and pressure of the washing step may be, for example, room temperature and atmospheric pressure, and the process time is not particularly limited, but if it is too short, the recovery amount of the rhodium catalyst is small, and if it is too long, it is economically disadvantageous without any particular advantage.

Next, the organic solvent (washing solvent) including the rhodium catalyst may be introduced into the first reactor 2 through the catalyst recovery line 9 and recycled. In the recycled organic solvent, the content of triphenylphosphine is high and the content of triphenylphosphine oxide is low, thereby increasing the stability of the catalyst and the efficiency of the hydroformylation reaction.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited to the examples.

Example 1

1000 g of a high temperature catalyst solution at 90 ° C. containing 20 wt% of triphenylphosphine, 36 wt% of triphenylphosphine oxide, 44 wt% of butyl aldehyde, and 900 ppm of rhodium was placed in a jacket-shaped bath maintained at 40 ° C. without stirring for 1 hour. Recrystallization produced a precipitate (precipitate) containing triphenylphosphine oxide (TPPO), and the resulting precipitate was separated by filtration. Next, the separated precipitate was washed with 200 ml of butyl aldehyde (specifically, the washing was carried out after the TPPO precipitate was precipitated in a round bottom flask, the solution layer was poured out to obtain a precipitate remaining on the bottom, and the obtained precipitate was dried and dried. The precipitate was placed in a filter and then subjected to suction filtering using an evaporator). The weight and rhodium content of the precipitate remaining after washing were measured, and the removal rate and rhodium loss rate of triphenylphosphine oxide (TPPO) were calculated based on the measured results, and the results are shown in Table 1 below.

[Example 2]

Except that 500 ml of butyl aldehyde was used as the washing solvent, the same method as in Example 1 was carried out. The removal rate and rhodium loss rate of triphenylphosphine oxide (TPPO) are shown in Table 1 below.

As a washing solvent, different solvents were applied to select a solvent capable of recovering rhodium without re-dissolving triphenylphosphine oxide (TPPO) in the precipitate.

Example 3

As a washing solvent of the precipitate separated from the catalyst solution, it was carried out in the same manner as in Example 1 except that diethyl ether was used, and the removal rate and rhodium loss rate of triphenylphosphine oxide (TPPO) were used. It is shown in Table 1 below.

Example 4

As a washing solvent of the precipitate separated from the catalyst solution, except that hexane (hexane) was used, it was carried out in the same manner as in Example 2, the removal rate and rhodium loss rate of triphenylphosphine oxide (TPPO) is shown in Table 1 below. Shown in

As the amount of washing solvent increased, the rhodium loss rate was reduced compared to the TPPO removal rate, so that the recovery of the rhodium catalyst was more efficient (Examples 1 and 2). V) Rhodium loss rate / TPPO removal rate and ii) Rhodium loss rate were the best in diethyl ether (Examples 2 to 4).

As described above, the present invention was carried out for the purpose of selectively removing only triphenylphosphine oxide (TPPO) from the hydroformylation catalyst solution to increase the catalyst stability and the efficiency of the oxo process. However, the loss of rhodium, the catalytic metal, is expected in the recrystallization process and a washing process is introduced to minimize it. In the results of Example 2, when the washing process is carried out, the removal rate of triphenylphosphine oxide (TPPO) is considerably reduced because the crystal mass which has been precipitated by the solvent melts back into the catalyst solution. On the other hand, the loss rate of rhodium is reduced to less than 2%, showing that the cleaning process is effective. In the case of Example 3 and Example 4, it is an example washed with an organic solvent other than butyl aldehyde. Of these, when washed with diethyl ether it was confirmed that compared to Example 2 in both the removal rate and the loss rate is very good results.

Example 5

1000g of the catalyst solution was used under the same operating conditions as in Example 1, and the washing method of the precipitate (precipitate) separated from the catalyst solution was changed. That is, 500 ml of butyl aldehyde that passed through the sediment through a single washing process was recycled to allow the sediment to pass through the sediment again (in addition to Example 1, the washing was performed to remove the solution layer directly on the bottom). After recrystallization of the catalyst solution in the glass reactor with the exit, the coexisting solution layer was discharged to the outside through the exit of the glass reactor, and the discharged solution was recycled to perform the rewashing process. And rewashing process was performed without using an evaporator). This process was repeated 10 times to determine the weight of the remaining precipitate and the rhodium content. Based on the measured results, the removal rate and rhodium loss rate of triphenylphosphine oxide (TPPO) were calculated and the results are shown in Table 2. In this case, the removal rate of triphenylphosphine oxide (TPPO) is also relatively high, and the rhodium loss rate is also significantly improved to 0.57%.

Example 6

The process of recirculating 500 ml of butyl aldehyde and rewashing was repeated 20 times, and other operating conditions were the same as in Example 5, and the analysis results are shown in Table 2. In this case, the removal rate of triphenylphosphine oxide (TPPO) was slightly lower, but the rhodium loss rate was the lowest.

Example 7

Under the same operating conditions as in Example 5, the solvent used in the washing process was used in the recrystallization process instead of the clean butyl aldehyde (F-BAL) so that the triphenylphosphine oxide (TPPO) was once removed in crystalline form. The solution (P-BAL) was used for 10 cycles of washing, and the analysis results are shown in Table 2. In this case, the removal rate of triphenylphosphine oxide (TPPO) was considerably high at 65%, but the rhodium loss rate was very high at 7%.

Example 8

Under the same operating conditions as in Example 7, the solvent used in the washing process was used in the recrystallization process instead of fresh butyl aldehyde (F-BAL) to remove triphenylphosphine oxide (TPPO) once in crystal form. The solution (P-BAL) was used for 20 cycles of washing, and the analysis results are shown in Table 2.

Example 9

When the washing was performed once using 500 ml of butyl aldehyde without performing the circulating washing under the same operating conditions as in Example 5, the analysis results are shown in Table 2. In this case, the triphenylphosphine oxide (TPPO) removal rate was high, but the rhodium loss rate was relatively high.

In Examples 5 to 9, a method of repeated washing was performed by applying a circulation of solvent to lower the rhodium loss rate than Example 2 (less than 2%). As a result, the rhodium loss rate was lowered to 0.57% while maintaining the triphenylphosphine oxide (TPPO) removal rate as 40% as in Example 5. In Example 6, the rhodium loss rate was lowered to 0.5%, but the triphenylphosphine oxide (TPPO) removal rate was lowered to about 34%. The same procedure as in Example 7 and Example 8 was obtained by applying the method of using the catalyst solution circulated in the process instead of pure butyl aldehyde and used for recrystallization.

The method for recovering a rhodium catalyst according to the present invention has an advantage of efficiently recovering a rhodium catalyst from a solid including a rhodium catalyst and triphenylphosphine oxide.

The method for recovering the rhodium catalyst according to the present invention is applied to the method for recovering the rhodium catalyst from the product of the hydroformylation reaction, which is removed together in the process of removing triphenylphosphine oxide (TPPO) from the product of the hydroformylation reaction. By minimizing the loss of the rhodium catalyst, there is an advantage to efficiently recover the rhodium catalyst, and thus there is an advantage to increase the stability of the catalyst and the efficiency of the hydroformylation reaction.

Although the present invention has been described in detail with reference to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the scope and spirit of the present invention, and such variations and modifications fall within the scope of the present invention. Of course.

Claims (11)

delete delete delete delete delete Distilling the product of the hydroformylation reaction to separate an aldehyde compound (iii) and a catalyst solution (ii) comprising a) a rhodium catalyst and b) triphenyl phosphine oxide; Recrystallization of the separated catalyst solution to precipitate and precipitate triphenylphosphine oxide; And Washing the precipitate comprising the filtered triphenylphosphine oxide with an organic solvent; A method for recovering a rhodium catalyst from a product of a hydroformylation reaction comprising a. The method of claim 6, A method for recovering a rhodium catalyst from a product of a hydroformylation reaction, wherein the organic solvent is the same compound as the reaction solvent. The method of claim 6, An organic solvent is selected from the group consisting of aldehydes, ketones, aromatic compounds, halogenated aromatic compounds, ethers, halogenated paraffin compounds, paraffin hydrocarbons and mixtures thereof. The method of claim 6, Organic solvents include propane aldehyde, butyl aldehyde, baler aldehyde, acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, cyclohexanone, benzene, toluene, xylene, orthodichlorobenzene, tetrahydrofuran, dimethoxyethane, di A method for recovering a rhodium catalyst from a product of a hydroformylation reaction, characterized in that it is selected from the group consisting of oxane, methylene chloride, heptane and mixtures thereof. The method of claim 6, The washing method is a rhodium catalyst recovery from the product of the hydroformylation reaction, characterized in that carried out in a continuous process. The method of claim 6, The washing is carried out by repeating two or more times in a rotational cycle rhodium catalyst recovery method from the product of the hydroformylation reaction.

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