DE2406323A1 - Continuous hydroformylation of olefinic cpds - using recycled rhodium-contg product-distn residue as catalyst in presence of water - Google Patents

Abstract

The continuous prodn. of O-contg. cpds. is carried out by (a) reacting a 2-20C olefinic cpd. with CO and H2 at 50-200 degrees C and 50-1000 atm. in the presence of 1-30 (pref. 3-26) wt.% H2O (based on the olefinic cpd.), initially using a soln. of a Rh cpd. in a non-polar solvent as catalyst; (b) separating unreacted starting material and reaction product from the reaction mixt. by fractional distn.; and (c) recycling the distn. residue, contg. dissolved Rh cpds. and a small amt. of suspended Rh, as catalyst for further reaction, opt. after replacing Rh losses with the corresp. amt. of fresh catalyst soln. By carrying out the reaction in the presence of H2O, the deactivation of the Rh catalyst during distn. is counteracted; although H2O reduces the reaction rate in the 1st run (with fresh catalyst), it greatly increases the rate when the recycled distn. residue is used.

Description

Continuous process for the creation of oxygen-containing compounds by oxo synthesis using the recovered rhodium catalyst of the invention is a continuous oxo process in which the catalyst is on separated from the reaction product by distillation and without further treatment can be returned to the synthesis stage.

It is known that the oxo synthesis for the production of oxygen-containing Compounds of olefinically unsaturated compounds, carbon monoxide and hydrogen can be carried out continuously in a reaction zone, with a solution a rhodium compound in a polar organic solvent as a catalyst serves. The rhodium compound is little or no olefinically unsaturated compound Compound soluble (GB-P8 1 202 507). A recovery and reuse of the rhodium is not mentioned here.

For the recovery of the rhodium-tin catalyst used in the oxo synthesis various methods are known.

One can, for example, oxo reaction mixtures, the rhodium hydrogen carbonyl Contained as a catalyst, pretreat with basic ion exchangers, the Rhodium is bound as carbonylate on the basic ion exchanger. It can then by treating the ion exchanger with a mixture of lower alcohols, Water and water solutions of aliphatic amines in the presence of molecular oxygen be eluted. The rhodium can be converted from the eluate by further treatment were recovered (DT-OS 2 045 416).

Furthermore, you can rhodium-containing reaction mixtures from the Conversion of unsaturated organic compounds with carbon oxide and hydrogen by treatment with certain metals as insoluble substances (DT-OS 1 558 395).

Finally, it is also known to use a rhodium catalyst Oxo reaction product by treating it with water and / or steam to be removed in the presence of a material acting as a carrier. Here the Rhodium compound decomposes and metallic rhodium is deposited on the carrier, from which it can then be recovered (DT-OS 1 945 475).

It was therefore desirable to develop a method in which the The rhodium catalyst is separated off in a simple manner and without laborious work-up measures can be used again as a catalyst for the synthesis. This task will solved by the inventive method.

The invention relates to a continuous process for production oxygen-containing compounds by reacting olefinically unsaturated compounds with 2 to 20 carbon atoms per molecule with carbon monoxide and hydrogen elevated temperature and pressure in the presence of a solution of a rhodium compound in an organic solvent. Ea is characterized in that the olefinic unsaturated compounds with carbon monoxide and hydrogen at 50 to 2000C and 50 to 1000 atm in Presence of 1 to 30% by weight of water, based on on the olefinically unsaturated compound, reacted, with one at the beginning of the reaction uses a solution of a rhodium compound in a non-polar solvent, the unreacted from the product obtained by fractional distillation The starting compound and the oxygen-containing reaction products are separated off and the remaining dissolved rhodium compounds and small amounts of suspended rhodium containing distillation residue as a catalyst, if necessary after replacement of rhodium losses through corresponding amounts of fresh catalyst solutions in recirculates the reaction stage.

The reaction is advantageously carried out in the presence of 3 to 26% by weight Water, based on the olefinically unsaturated compound carried out.

The water content of the reaction mixture is expediently determined by separate Maintain the feed of water.

Particularly suitable catalytically active compounds are rhodium compounds higher carboxylic acids with 4 to 20 carbon atoms. You put them in Solution in benzene, toluene or dissolved in the feed olefin (e.g. in diisobutylene). They are easily soluble in this and can be metered in particularly easily from a technical point of view will.

The new process is based on the observation that in the oxo product with discharged rhodium catalyst in the distillation of this product in a Column with a sufficiently large number of plates remains almost quantitatively in the bottom residue.

However, it was found that this dissolved or suspended in the sump residue Rhodium is not very suitable as a catalyst for the hydroformylation of olefins. As a result the previous distillation, the rhodium is deactivated. This deactivation of the rhodium catalyst can be carried out by the process according to the invention can be reversed1 It is true that this addition of water reduces the reaction rate the hydroformylation with the first use of rhodium Prischkontakt, however show the experimental examples that the addition of water when the rhodium is reused containing distillation residues very favorably on the reaction rate of the Hydroformylation affects.

The distillation of the oxo-Rh products is expedient here in one Column carried out with 5 to 10 theoretical plates, the bottom temperature Should not exceed 1000C.

The advantages of the method according to the invention are demonstrated by the following Examples illustrated. Example 1 is a comparative example in which under the usual conditions of the oxo synthesis is carried out without the addition of water.

Examples 2 and 3 give embodiments of the procedure according to the invention again with the addition of different amounts of water. Ee each was an attempt a) carried out with freshly used catalyst, while in the following as a catalyst in each case that in the distillation of the product of the preceding Experiment obtained rhodium-containing residue was used. When the reactor was A 4.4 liter stainless steel autoclave was used in all experiments. the Conversion of the olefin was carried out under the following conditions: synthesis gas CO / H2 "1/1 synthesis gas pressure 250-290 at reaction temperature 130 ° C.

The reaction products of the individual experiments were each in one Distilled column with 5 to 6 theoretical plates. The maximum Sump temperature 10000 and the minimum pressure 15 Torr applied. In the distillate were 0.5 ppm rhodium detected. The distillation residues containing rhodium were each added with the starting olefin of the following stage and used as a catalyst used in the following experiment.

The reaction products became after the course of certain reaction times each analyzed by gas chromatography and the test results in the following Tables compiled.

Example 1 (comparative example) hydroformylation without the addition of Water feedstock olefin 1430 g diisobutylene (2.0 l) rhodium catalyst 14.3 mg of Rh, as Rh-2-ethylhexanoate dissolved in toluene (14.3 ml), hydroformylation test results Reactive GLC analysis of the reaction product used onszeit duct octane butylene Aldehyde alcohol (%) (%) (%) (%) a) 1430 g diisobutylene 3 2.4 0.3 95.6 1.7 14.3 g Rh (fresh contact) b) 1430 g of diisobutylene 3 1.2 25.2 72.5 1.1 bottom residue from t) 6 1.3 2.3 95.0 1.4 9 1.9 0.8 95.4 1.9 c) 1430 g of diisobutylene 3 0.4 47.2 51.1 1.3 Samp residue from b) 6 0.4 37.6 60.6 1.4 9 0.5 32.3 65.8 1.4 b) 1430 g of diisobutylene 3 0.5 60.1 38.4 1.0 bottom residue from c) 6 0.6 51.4 47.0 1.0 9 0.6 44.3 54.0 1.1 e) 1430 g of diisobutylene 3 0.5 60.4 37.9 1.2 bottom residue au. d) 6 0.6 51.6 46.5 1.3 9 0.6 49.9 48.2 1.3 Example 2 Hydroformulation with Additive of 3% by weight of water, olefin feedstock 1430 g of diisobutylene (2.0 l) of rhodium catalyst 14.3 mg of Rh, as Rh-2-ethylhexanoate dissolved in toluene (14.3 ml) of water, 43 g of test results Hydroformulation Reacti- GLC analysis of the reaction per input product at the moment (h) i-diiso- C9- C9-octane butylene aldehyde acoliol (%) (%) (%) a) 1430 g diisobutylene 14.3 mg Rh (fresh contact) 43 g water 3 1.1 8.2 90.2 0.5 b) 1430 g diisobutylene Sump residue from a) 43 g of water 3 1.5 2.4 95.6 0.5 c) 1430 g of diisobutylene sump residue from b) 43 g of water d) 1430 g of diisobutylene bottom residue from c) 43 g of water 3 1.1 5.2 92.8 0.9 e) 1430 g of diisobutylene bottom residue from d) 43 g of water 3 1.0 6.6 91.4 1.0 f) 1430 g of diisobutylene bottom residue from e) 0.8 10.9 88.1 0.7 43 g of water g) 1430 g of diisobutylene bottom residue from f) 43 g of water 3 0.8 13.9 84.6 0.7 example 3 Hydroformylation with the addition of% by weight of water. Olefin feedstock 1430 g of diisobutylene (2.0 l) Rhodium catalyst, 14.3 mg of Rh, as Rh-2-ethylhexanoate dissolved in toluene (14.3 ml) water 500 g test results hydroformulation reacti- GLC analysis of the reaction product Input products at the moment ductile (h) i-diiso- C9- C9-octane butylene aldehyde alcohol (%) (%) (%) (%) a) 1430 g diisobutylene 14.3 mg Rh (fresh contact) 500 g water 3 1.7 19.7 78.3 0.3 b) 1430 g of diisobutylene 3 0.7 13.0 85.9 0.4 bottom residue from a) 6 0.8 8.8 89.6 0.8 500 g water 9 0.8 6.2 92.2 0.8 c) 1430 g diisobutylene 3 0.8 13.9 84.7 0.6 bottom residue from b) 6 0.8 8.9 89.5 0.8 500 g water 9 0.8 5.3 92.9 1.0 d) 1430 g of diisobutylene 3 0.8 11.7 86.5 1.0 sump residue from c) 6 0.9 2.4 95.3 1.4 500 g water 9 0.9 1.2 95.8 2.1 e) 1430 g diisobutylene 3 0.7 12.5 85.4 1.4 bottom residue from d) 6 0.8 7.8 89.6 1.8 500 g water 9 0.9 3.1 93.5 2.5 f) 1430 g diisobutylene 3 0.6 14.4 81.8 3.2 Bottom residue from e) 6 0.7 7.6 88.3 3.4 500 g of water 9 0.8 3.6 92.2 3.4

Claims (4)

Claims 1.) Continuous process for the preparation of oxygen-containing compounds by reacting olefinically unsaturated compounds having 2 to 20 carbon atoms per molecule with carbon monoxide and hydrogen at elevated temperature and pressure in the presence of a solution of a rhodium compound in an organic solvent, characterized in that the converts olefinically unsaturated compounds with carbon monoxide and hydrogen at 50 to 200 ° C and 50 to 1000 atm in the presence of 1 to 30% by weight of water, based on the olefinically unsaturated compound, at the beginning of the implementation a solution of a RhodS uses compound in a non-polar solvent, from the product obtained by fractional distillation the unreacted starting compound and the oxygen containing reaction products separated and the remaining, dissolved rhodium compounds and small amounts suspended Distillation residue containing rhodium as a catalyst, optionally after replacing rhodium losses with appropriate amounts of fresh catalyst solutions, returned to the reaction stage. 2.) The method according to claim 1, characterized in that the implementation in the presence of 3 to 2% by weight of water, based on the olefinically unsaturated compound, is carried out. 3.) The method according to claim 1 and 2, characterized in that the The water content of the reaction mixture is maintained by a separate feed of water is obtained. 4.) Process according to claim 1 to 3, characterized in that rhodium compounds higher carboxylic acids than catalytically active compounds in solution in benzene, toluene or the feed olefin can be used.