CS199333B1 - Process for the hydroformylation of olefines - Google Patents

Description

SUMMARY OF THE INVENTION The present invention provides a process for hydroformylating olefins at elevated temperature and pressure in the presence of cobalt carbonyl, followed by converting the cobalt carbonyl into a cobalt salt with organic acids, separating the reaction products from the cobalt salt solution by distillation and recirculating cobalt salt solution.

In the conversion of olefins by reaction with carbon monoxide and hydrogen to aldehydes and alcohols having 1 carbon atom more than the olefins used, at elevated temperature and elevated pressure according to the so-called hydroformylation reaction, the catalysts used are, inter alia, salts of higher organic carboxylic acids such as naphthenic acids , oleic acid, lauric acid and 2-ethylhexanoic acid, β cobalt. The hydroformylation process is particularly simple when high-boiling distillation residues are used as solvent for the catalyst and the cobalt catalyst solution is recovered after the cobalt carbonyl has been destroyed by distilling off the aldehydes and alcohols formed.

Thus it is known to carry out the hydroformylation of olefins at elevated pressure and elevated temperatures with a naphthene, oleate or cobalt butyrate dissolved in high-boiling distillation residues as a catalyst. The breakdown of the cobalt carbonyl in the reaction product is achieved either by reducing the partial pressure of carbon monoxide, or by exposure to air. By distilling off the resulting aldehydes and alcohols, the cobalt catalyst solution used is obtained

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199 333 and can then be reused.

Further, a process is known in which the carbonyl compounds of cobalt in the reaction mixture are oxidatively converted to non-volatile cobalt compounds, whereupon the reaction products are subjected to rapid evaporation. The resulting distillation residue contains a solution of trivalent cobalt salts and can be reused as a catalyst solution in the reaction zone. The oil-soluble cobalt salts are obtained by introducing oxygen-containing gases or air into the reaction product containing cobalt carbonyls in the presence of 0.1-5.0% water and at a preferred pH in the range of 4-6.

The disadvantage of these processes is that it is necessary to compensate for the losses of cobalt catalyst in the form of oil-soluble cobalt salts during the process. However, for the production of oil-soluble organic cobalt salts to replace the losses of cobalt catalyst during hydroformylation, a special step for the synthesis of these cobalt salts should be established,

In hydroformylation plants on a factory scale, the existence of such a special stage leads to a considerable complication and price increase of the overall hydroformylation technology, in addition to this, a considerable amount of heavily polluted waste water is generated and cobalt catalyst losses are lost.

The purpose of the invention is to simplify the process technology and reduce cobalt losses in the manufacture of the catalyst.

The object is to adapt the process technology so that it is possible to dispense with a separate synthesis stage for the production of oil-soluble cobalt salts, a step which has hitherto been necessary to compensate for cobalt catalyst losses.

This object is achieved by the process of hydroformylating olefins at elevated temperature and elevated pressure in the presence of cobalt carbonyl followed by conversion of cobalt carbonyl to cobalt organic acid salts by distillation of the reaction products from the cobalt aole solution and recirculating the cobalt salt solution to the process. The method is characterized in that, in order to replace the catalyst losses, cobalt or its compounds, for example cobalt hydroxide, cobalt oxide, cobalt carbonate, are injected in an amount of 0.5 to 2.5 g of cobalt / kg of cobalt salt solution to the carbonyl formation stage. , and higher C 8 -C 18 organic acids, preferably naphthenic acid, 2-ethyl hexanoic acid, lauric acid, 2-ethylhexenoic acid and oleic acid, in an amount of 2 to 3 moles / mol of cobalt are injected to the stage where carbonyls are formed, at temperatures of 150 to 200 ° C and at a pressure of 200 to 200 ° C Or at a later stage prior to oxidative deburring, in particular to a decobaltizer at temperatures of from 30 to 100 ° C and at a pressure of from 1 to 10 bar.

Suitably, in the process according to the invention, the cobalt compounds are added to the cobalt carbonyls step and the higher carboxylic acids to the cobalt carbonyl decomposition steps. However, it is also possible that the carboxylic acids, together with the cobalt compounds, are added to the carbonyl-forming step in the production process.

199 333 cobalt.,

The production of cobalt carbonyl is very preferably carried out at a temperature of about 170 ° C in the pre-hydroformylation step to allow hydroformylation to achieve optimal product composition at the appropriate low temperatures (about 130 ° C). In one step, the rate of formation of the jarbonyl is reduced to such an extent that a low yield in the hydroformylation reaction per unit space and Sase can be achieved.

However, if the system is operated without the carbonyl-forming step, the cobalt and its compounds and possibly the higher carboxylic acids can be injected directly into the hydroformylation reactor.

An advantage of the process according to the invention is that the hydroformylation of olefins does not require a special step for obtaining the oil-soluble cobalt catalysts required in the process to cover the losses of the cobalt catalyst. The oil-soluble cobalt salts for the replacement of cobalt catalyst losses are prepared according to the invention in the process of hydroformylation of olefins. The cobalt compounds used are converted into cobalt carbonyl which catalyze hydroformylation in the carbonyl-forming step, and in the cobalt carbonyl disrupting step they are formed from cobalt carbonyl in the presence of oxygen and higher carboxylic acids in the oil-soluble cobalt salt. The process according to the invention eliminates the costly, intermittent process for producing oil-soluble cobalt salts. The process for olefin hydroformylation is thereby simplified and economical.

A further advantage of the process according to the invention is that it reduces the losses of the cobalt catalyst and avoids the generation of waste water.

The invention is illustrated by the following examples.

Example 1

A mixture of 1000 g of cobalt-containing bottom residues (18 g of cobalt in a cobalt naphthenate melt) which, after oxidation decobaltation and separation of the reaction products by distillation, 2.5 g of cobalt oxide and 20 g of naphthenic acid is injected into the stage to form carbonyls. The reaction to obtain the cobalt carbonyl is carried out at a temperature of 175 ° C and a synthesis gas pressure of 25.9 MPa.

In the presence of the cobalt catalyst solution thus obtained, to which 2 kg of toluene has been added, 10 kg of propylene are hydroformylated at a temperature of 130 ° C and at a pressure of 25 MPa.

The resulting reaction mixture is treated with air at 50 ° C and 4 t at a pressure to convert the cobalt carbonyls contained in the reaction mixture to an oil-soluble cobalt salt. By distillation of this cobalt-free carbonyl reaction product, 14.7 kg of butyraldehydes, 0.4 kg of butanols and a cobalt catalyst solution are obtained which can be re-circulated to the production process.

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Cobalt losses are 0.038 g / kg butyraldehydes and butanols.

Example 2

A mixture of 1000 g of cobalt-containing bottoms of dnt (18 g of cobalt in the form of cobalt oleate), obtained by oxidative decobaltation and separation of the reaction products by distillation, and 4 g of cobalt carbonate are injected to the carbonyl formation stage. The reaction to form the cobalt carbonyl is carried out at a temperature of 175 ° C and a synthesis gas pressure of 25.0 MPa.

In the presence of the catalyst solution thus obtained, 10 kg of propylene are hydroformylated at a temperature of 130 DEG C. and at a pressure of 25 bar. The reaction mixture obtained, to which 21 g of oleic acid was added, was treated with air at a temperature of 50 ° C and a pressure of 0.4 MPa. The cobalt carbonyls contained in the reaction mixture are thus converted into the oil-soluble cobalt salts. By distillation of the reaction product containing no cobalt carbonyls, 14.9 kg of butyraldehydes, 0.3 kg of butanols and a catalyst solution can be recycled to the process. Catalytic losses are 0.040 g / kg of butyraldehydes and butanols.

Example 3

A mixture of 1500 g of cobalt-containing residues of the day (15 g of cobalt in the form of 2-ethylhexene cobalt), obtained after oxidative decontamination and separation of the reaction products by distillation, 1 g of cobalt powder and 6 g of 2-ethylhexyl acid is injected to the stage carbonyls are formed. The reaction to form the cobalt carbonyl is carried out at 175 ° C under a synthesis gas pressure of 25.0 MPa,

In the presence of the cobalt catalyst solution thus obtained, kg of butyrene is hydroformylated at a temperature of 130 ° C and at a pressure of 25 MPa. The reaction mixture obtained is treated with air at a temperature of 50 ° C and a pressure of 4 at. The cobalt carbonyls contained in the reaction mixture are thus converted into the oil-soluble cobalt salts. By distillation of this cobalt-free carbonyl reaction product, 12.4 kg of valeraldehydes and amyl alcohols are obtained, as well as a catalyst solution which can be recirculated to the production process.

Catalytic losses are 0.036 g / kg valeraldehydes and amyl alcohols.

Claims (2)

BACKGROUND OF THE INVENTION A process for the hydroformylation of olefins at elevated temperature and elevated pressure in the presence of cobalt carbonyl followed by conversion of cobalt carbonyl to organic β cobalt salts by distillation of the reaction products from the cobalt salt solution and recirculation of the cobalt salt solution to the process. For catalyst losses, cobalt or its compounds, such as cobalt hydroxide, cobalt oxide, cobalt carbonate, are injected at a rate of 0.5 to 2.5 g of cobalt / kg of cobalt salt solution to the carbonyl-forming step and higher organic acids; 18 preferably 8 naphthenic acids, 2-ethylhexanoic acid, lauric acid, acid 199 333 2-ethylhexenoic acid and oleic acid, in an amount of 2 to 3 moles of cobalt, are injected into the carbonyl-forming stage at temperatures of 150 to 200 ° C and at a pressure of 20 to 35.0 MPa or later before the oxidation by de-cobaltization, in particular to a decobaltizer at temperatures of from 30 to 100 ° C and at a pressure of from 1 to 10 bar.