DE948150C - Process for the continuous production of oxygen-containing compounds - Google Patents

Description

Process for the continuous production of oxygen-containing compounds It is known that by reacting olefins with carbon oxide and hydrogen (synthesis gas) in the presence of cobalt or cobalt compounds at elevated temperature and below High pressure oxygen-containing compounds, primarily aldehydes or those derived from them derived alcohols. Usually used as catalysts for this Process called oxo synthesis can be used in metallic cobalt or in Use special solvents dissolved cobalt compounds from which in the course the reaction, the effective catalyst cobalt carbonyl or its hydride is formed will. Undoubtedly the easiest method is to use the catalyst in the implementation to bring in the use of aqueous cobalt salt solutions. That kind of catalysis has, however, in the implementation of olefins, which are liquid under normal conditions are, the disadvantage that no homogeneous phase is formed, but that the olefin and the aqueous solution is present in separate phases in the reaction vessel.

This makes the process more difficult, especially when it is carried out continuously shall be. So far, the supplier of cobalt carbonyl has been continuous Works metallic cobalt or cobalt compounds in solid form and used this by passing the gases to be converted into the reaction mass brought. In this procedure, however, the dosage of the cobalt carbonyl addition to the to be oxidized olefin very difficult, since z. B. the particle size and the surface finish of the raw material used for the delivery of the cobalt carbonyl is not uniform are.

It has now been found that the oxo reaction is also normally liquid olefins using aqueous cobalt salt solutions satisfactory can be carried out continuously when a mixture of the liquid starting olefin and the aqueous cobalt salt solution treated with synthesis gas under conditions which although a formation of cobalt carbonyls, but not the oxo reaction or occurs only to a minor extent, the aqueous mixture from the mixture treated in this way Phase separated and the non-aqueous phase with synthesis gas under the conditions the oxo reaction treated.

The first stage of the reaction is preferably carried out at temperatures carried out continuously between 80 and 1400, the synthesis gas being advantageous applies under the pressure under which the actual oxo reaction is carried out will. The ratio of carbon oxide and hydrogen can be chosen as desired will; in general a ratio of 1: 1 is used.

The low molecular weight salts are usually used as cobalt salts Fatty acids, especially cobalt acetate or propionate. The procedure is however can also be carried out with other soluble salts of cobalt. It is also possible acidify or buffer the cobalt salt solutions, although this is against the Using the simple cobalt salt solutions does not entail any significant advantages brings. The concentration of the cobalt salt solution is generally between I and 5 ° / o.

The cobalt salt solution is based on the amount of the olefin to be converted preferably used in an amount such that the olefin is about 0. OI to 0.1 Contains O / o cobalt.

The mixture resulting from the first stage of the process becomes useful without expansion, in a separator into an aqueous and a non-aqueous phase disassembled. The non-aqueous phase then goes to the oxidation stage without further treatment, while the aqueous solution after - replenishment of the consumed and in the non-aqueous Phase transferred cobalt can use again.

The actual oxo reaction takes place under the usual conditions carried out. In general, temperatures between 150 and 200 ° are used under a pressure of at least 100, expediently between 200 and 400 at.

In principle, higher pressures can also be used if they are for this necessary equipment is available.

The second stage of the process is also preferably continuous carried out. For example, one can work in the sump phase by doing the cobalt-containing olefin through a vertical pressure-tight vessel from bottom to top lets flow and at the same time syngas, expediently in the circuit, passes through.

To find the most favorable reaction temperature for the exothermic reaction To be able to comply, you can the reaction vessel in the usual way from the outside, for example by pressurized water circulation cooling or by evaporation of a suitable coolant, cool It is precisely here that the use of the sump phase process is particularly effective favorable because the heat transfer from the reaction liquid via the wall of the Pressure vessel to the coolant is very effective. But you can also use the cooling make by circulating part of the reaction product and cools down according to the expected heat generation. Also a combination both measures are possible. likewise the use of a gas cycle.

Example Through a vertical high-pressure pipe with a volume of 1 liter hourly at 16010 and 300 at 10000 ccm of a hexylene (bp = 60 to 700, iodine number 300, d20 9.698) and ITOO ccm of a 2.50 / above aqueous solution of carbonate acetate (0.670 / 0 containing ionic cobalt) pumped from the bottom upwards, while at the same time IO Ncbm synthesis gas (1: 1) are circulated. The one emerging from this pipe liquid mixture passes through a high pressure separator, from which the settling aqueous solution is continuously withdrawn, while the non-aqueous solution that now 0.03% cobalt in the form of active cobalt carbonyl or cobalt carbonyl hydrogen without relaxation from below into a vertical high-pressure pipe from 35 1 content occurs continuously. By this determined for the oxo reaction Pipe is introduced under 300 at at 1800 from below so much synthesis gas that every hour I Ncbm exhaust gas is relaxed. Every hour you get about goo g raw from the pipe Heptylaldehyde mixture with a density of 0.835 and an iodine number of about 15, what corresponds to an olefin conversion of 950 / o.

The aqueous solution withdrawn from the separator still contains 0.280 / o dissolved cobalt and after the cobalt content has been supplemented to about 0.670 / 0 Dissolving cobalt axetate returned to the first tube.

Claims (1)

PATENT CLAIM: Process for the continuous production of oxygen-containing of organic compounds after the oxo reaction by reacting under normal Conditions of liquid olefins with carbon monoxide and hydrogen (synthesis gas) in the Heat and under increased pressure in the presence of cobalt compounds by treatment Aqueous cobalt salt solutions obtained with synthesis gas under pressure and in the warmth have been, characterized in that a mixture of the liquid starting olefins and treated the aqueous cobalt salt solution with synthesis gas under conditions which although a formation of cobalt carbonyls, but not the oxo reaction or occurs only to a minor extent, the aqueous mixture from the mixture treated in this way Phase separated and the non-aqueous phase with synthesis gas under the conditions the oxo reaction. Considered publications: German Patent No. 849 103; Critical Patent No. 662,528.