Method for automating hydroformylation

Abstract

The present invention relates to a method for the continuous hydroformylation of olefins with synthesis gas in the presence of a cobalt catalyst, wherein the method is automated by the use of APC control with at least three controlled variables A, B and C.

Description

[0001] 202400226 Abroad

[0002] 1

[0003] Methods for automating hydroformylation

[0004] The present invention relates to a process for the continuous hydroformylation of olefins with synthesis gas in the presence of a cobalt catalyst, wherein the process is automated by the use of an APC control system with at least three control variables A, B and C.

[0005] Alcohols with more than six carbon atoms can be produced by the catalytic hydroformylation of olefins with one fewer carbon atom, followed by catalytic hydrogenation of the resulting mixtures of aldehydes and alcohols. The resulting alcohols are primarily used in the production of plasticizers and detergents. Furthermore, the aldehydes produced by hydroformylation can be isolated from the reaction mixtures by distillation for use in other applications, such as the production of carboxylic acids.

[0006] Processes for the hydroformylation of olefins are generally known and have been published extensively. An example is WO 2009 / 080396 A1, which discloses a one-step continuous process for the hydroformylation of olefins with at least 5 carbon atoms. The hydroformylation is carried out with synthesis gas in the presence of unmodified cobalt catalysts in a process where, in the presence of an aqueous and an organic phase, catalyst formation, catalyst extraction, and hydroformylation take place in the same reactor.

[0007] A key feature of the process disclosed in WO 2009 / 080396 A1 is maintaining a constant level of the aqueous sump phase in the reactor. Appropriate measures were taken to improve the process. However, it has become apparent that the process can only be operated particularly efficiently if the level of the aqueous sump phase, i.e., the position of the interface between the aqueous and organic phases in the reactor, is determined as precisely as possible. In the past, however, such precise determination was hardly achievable.

[0008] Inaccuracies in determining the level of the aqueous sump phase can lead to fluctuations in the extraction of the catalyst into the organic phase. This can result in conversion and / or temperature fluctuations in the reactor, complicating continuous operation with consistent reaction quality. The entire reaction process becomes more difficult and therefore inconsistent.

[0009] The task was therefore to provide a hydroformylation process that did not have the aforementioned disadvantages. In particular, a process was to be provided that could be operated with consistent quality and as few fluctuations as possible.

[0010] At the same time, the process should enable full automation, allowing the entire process to be operated continuously. 202400226 Abroad

[0011] 2

[0012] This problem was solved by the method according to claim 1. Preferred embodiments of the method according to the invention are specified in the dependent claims.

[0013] The present invention therefore relates to a process for the continuous hydroformylation of olefins with 5 to 24 carbon atoms, preferably 8 to 16 carbon atoms, with synthesis gas in the presence of a modified or unmodified, preferably an unmodified, cobalt catalyst in at least one reactor, wherein

[0014] The olefins in the form of an olefin stream, an aqueous cobalt salt solution and the synthesis gas are continuously fed to at least one reactor,

[0015] in which at least one reactor contains an aqueous sludge phase and an organic phase located above the aqueous sludge phase, wherein the organic phase contains the reaction products, and

[0016] Continuously, a portion of the aqueous sludge phase and a portion of the organic phase are taken from at least one reactor, whereby

[0017] The procedure uses an APC control system with at least three controlled variables A, B and C, whereby the following conditions I), II) and III) are met during the procedure, wherein

[0018] I) the controlled variable A is the reaction conversion, the yield or the input factor and represents the target controlled variable, wherein either a specific target value or a specific range of target values ​​is specified for the controlled variable;

[0019] II) for the controlled variable B is the state of the aqueous sump phase, for which a setpoint is specified and the controlled variable B is kept constant around the setpoint, and

[0020] III) for the controlled variable C, the reaction temperature in which there is at least one reactor, for which an unchanging limit value (setpoint) is set which must not be exceeded or fallen below.

[0021] The method according to the invention has the advantage that automated operation is made possible by the APC control. This eliminates human error and simplifies process control. Furthermore, it allows the process to be operated with fewer fluctuations and thus more efficiently.

[0022] The underlying process is a hydroformylation process in which olefins with 5 to 24 carbon atoms, preferably olefins with 8 to 16 carbon atoms, are reacted with synthesis gas in the presence of a modified or unmodified, preferably an unmodified, cobalt catalyst in at least one reactor. 202400226 Abroad

[0023] 3

[0024] In principle, all olefins with at least 5 and at most 24 carbon atoms can be used as starting materials for the process according to the invention. Suitable olefins are primarily available in the form of olefin mixtures, in which different isomeric olefins with the same, similar (+ / - 2 C atoms), or significantly different (> + / - 2 C atoms) number of carbon atoms are generally present together as alkanes. Preferably, olefins or olefin mixtures with 8 to 16 carbon atoms are used.

[0025] Examples of olefins that can be used as starting materials, either in pure form, in a mixture of isomers, or in a mixture with other olefins with varying numbers of carbon atoms, include: 1-, 2-, or 3-hexene, 1-heptene, linear heptenes with an internal double bond (2-heptene, 3-heptene, etc.), mixtures of linear heptenes, 2- or 3-methyl-1-hexene, 1-octene, linear octenes with an internal double bond, mixtures of linear octenes, 2- or 3-methylheptene, 1-nonene, linear nonenes with an internal double bond, mixtures of linear nonenes, 2-, 3-, or 4-methyloctene, 1-, 2-, 3-, 4-, or 5-decene, and 2-ethyl-1-octene. 1-Dodecene, linear dodecenes with an internal double bond, mixtures of linear dodecenes, 1-tetradecene, linear tetradecenes with an internal double bond, mixtures of linear tetradecenes, 1-hexadecene, linear hexadecenes with an internal double bond and mixtures of linear hexadecenes.

[0026] Suitable starting materials also include, among others, the mixture of isomeric hexenes (dipropene) obtained from the dimerization of propene, the mixture of isomeric octenes (dibutene) obtained from the dimerization of butenes, the mixture of isomeric nonenes (tripropene) obtained from the trimerization of propene, the mixture of isomeric dodecenes (tetrapropene or tributene) obtained from the tetramerization of propene or the trimerization of butenes, the hexadecene mixture (tetrabutene) obtained from the tetramerization of butenes, and olefin mixtures produced by cooligomerization of olefins with different carbon numbers (preferably 2 to 4), optionally separated by distillation into fractions with the same or similar (+ / -2) carbon numbers.

[0027] Preferred starting materials for the process according to the invention are mixtures of isomeric octenes (C8 olefins), nonenes (C9 olefins), dodecenes (C12 olefins) or hexadecenes (C16 olefins), i.e. oligomers of low olefins, such as n-butenes, isobutene or propene. If C8, C12 or C16 olefin mixtures are the starting materials, those prepared by oligomerization of linear butenes on nickel fixed-bed catalysts are particularly suitable.

[0028] The olefins used in the process are hydroformylated with synthesis gas. The synthesis gas, i.e., a mixture of carbon monoxide and hydrogen, for the process according to the invention can be used in different mixing ratios of carbon monoxide and hydrogen. In the synthesis gas used, the mixture of hydrogen and carbon monoxide, the volume ratio of hydrogen to carbon monoxide is preferably in the range of 1:2 to 2:1.

[0029] The molar ratio between synthesis gas and the hydrocarbon stream used, which contains the olefins to be hydroformylated, should be between 6:1 and 1:1, preferably between 3:1 and 1:1.

[0030] 4

[0031] The ratio is particularly preferred between 2:1 and 1:1. The hydroformylation can optionally be carried out in the presence of an additional solvent known to those skilled in the art; however, preferably no additional solvent is used, and the olefin used and / or the aldehyde formed act as the solvent in the hydroformylation.

[0032] The hydroformylation process according to the invention is carried out in the presence of a modified or unmodified cobalt catalyst. Unmodified cobalt catalysts refer to cobalt hydridocarbonyl complexes, for example, cobalt tetracarbonyl hydrogen (HCo(CO)4) and / or dicobalt tetracarbonyl hydrogen. Unmodified cobalt catalysts are complexed with carbonyl groups and do not contain any organic ligands. In contrast, the term modified cobalt catalysts means that the catalyst complex contains organic ligands. This is known to those skilled in the art.

[0033] The use of unmodified cobalt catalysts is preferred in the present process. The formation of such catalysts is known to those skilled in the art, for example, from DE 196 54340 A1. The starting point is an aqueous cobalt salt solution. Water-soluble cobalt salts, such as formates and acetates, are preferably used. Cobalt acetate has proven particularly effective, preferably as an aqueous solution with a cobalt content of 0.2 to 2 wt.%, and especially preferably 0.5 to 1.5 wt.%, calculated as the metal.

[0034] Under synthesis gas pressure, the cobalt is pre-carbonylated in the aqueous cobalt solution. From the aqueous cobalt solution, the pre-carbonylated cobalt, as a cobalt hydridocarbonyl complex, passes from the aqueous bottom phase into the organic phase in the reactor. This normally requires an extraction solvent. The extraction solvent needed to extract the cobalt catalyst from the aqueous bottom phase can be any organic solvent that is immiscible or only sparingly miscible with water, provided it has sufficient solubility for the cobalt catalyst. In the context of the present invention, the extraction solvent is the mixture of the olefin to be hydroformylated and the aldehydes and / or alcohols formed during the hydroformylation. Therefore, in this case, the extraction solvent is already present in the reactor as an organic phase.

[0035] The formation of the cobalt catalyst can, in principle, also be carried out in a pre-reactor. However, the present invention preferably relates to a one-stage continuous hydroformylation process in which the formation of the active cobalt catalyst from an aqueous cobalt salt solution, extraction of the active catalyst from the aqueous phase into the organic phase, and hydroformylation take place simultaneously in the reactor.

[0036] Because a portion of the organic phase and a portion of the aqueous sludge phase, each containing cobalt salts and / or cobalt catalyst, are continuously drawn off from at least one reactor, the aqueous cobalt solution must be continuously replenished to ensure a sufficient amount of catalyst in the reaction system. 202400226 Abroad

[0037] 5

[0038] In the process according to the invention, 2 to 99 wt%, in particular 5 to 80 wt% and most particularly 10 to 60 wt% of the water fed into the reactor with the cobalt salt solution are removed by drawing off a portion of the aqueous sludge phase. The proportion of water that is drawn off from the reactor with the aqueous sludge phase depends mainly on the olefins to be hydroformylated and the hydroformylation temperature.

[0039] In a homologous series of aldehydes or alcohols that can be formed during hydroformylation, the solubility of water decreases with increasing molar mass. Consequently, with increasing molar mass of the reactant, less and less water is transported out of the at least one reactor with the liquid reaction mixture as the organic phase. Therefore, an increasing proportion of water must be removed by drawing off a portion of the aqueous sludge phase from the reactor. The optimal conditions can be easily determined by a person skilled in the art through preliminary experiments.

[0040] Hydroformylation is preferably carried out in the temperature range of 110 to 250 °C, more preferably in the temperature range of 130 to 220 °C, and most preferably in the temperature range of 160 to 190 °C. The reaction pressure during hydroformylation is preferably in the range of 100 to 400 bar, and more preferably in the range of 150 to 300 bar.

[0041] The hydroformylation process described herein will be carried out in at least one reactor. Several reactors can therefore be operated simultaneously. The hydroformylation is performed in a high-pressure reactor, preferably a cascaded bubble column reactor, into which the olefins, the aqueous cobalt salt solution, and the synthesis gas are introduced, preferably via a mixing nozzle. If several reactors are used, they can be of the same or different types.

[0042] In the hydroformylation process according to the invention, the feed olefin or olefin mixture, the aqueous solution containing the cobalt compounds, and the synthesis gas are introduced into the sump of at least one reactor. The sump of the reactor contains an aqueous phase in which small amounts of organic phase are dispersed.

[0043] To obtain a high reaction rate, it is advantageous to mix the aqueous sludge phase with the organic phase, synthesis gas, and aqueous cobalt salt solution. Intensive mixing prevents concentration gradients of the reactants. Furthermore, mixing the aqueous sludge phase with the organic phase promotes the transfer of the formed catalyst into the organic phase, where the hydroformylation primarily takes place.

[0044] 6

[0045] The mixing of the reaction components olefin, synthesis gas, aqueous cobalt salt solution with themselves and / or hydroformylation mixture, as well as the mixing of the two liquid phases in the reactor, can be carried out using suitable technical equipment.

[0046] Olefin, synthesis gas, and aqueous cobalt salt solution can be introduced separately, preferably through nozzles, into at least one reactor. Alternatively, two components can be fed together through one or more mixing nozzles, and the third component separately into the reactor.

[0047] However, it is advantageous to feed all three components together through one or more mixing nozzles into at least one reactor.

[0048] The aqueous sludge phase can be circulated using a pump installed in a recirculation line. Mixing of the aqueous sludge phase with the organic phase and synthesis gas can also be achieved by feeding a portion of the aqueous phase from the at least one reactor to the mixing nozzle for the feedstocks. This can be done using a pump. Alternatively, a portion of the aqueous sludge phase from the at least one reactor can be drawn into the mixing nozzle by the material flow.

[0049] The reaction mixture from the hydroformylation reactor contains reactants (olefins), products (aldehydes, alcohols), byproducts, and cobalt carbonyl complexes. The cobalt carbonyl complexes can be separated from the reaction mixture using known technical methods.

[0050] The separation of cobalt carbonyls is preferably carried out oxidatively. For this purpose, the reaction mixture is partially depressurized, particularly to 10 to 15 bar, and reacted in the presence of an acidic cobalt(II) salt solution with oxygen-containing gases, especially air or oxygen, at temperatures of 90 °C to 160 °C in a reactor (decobalt reactor) and thus oxidatively freed from cobalt carbonyl compounds. These are destroyed in the process, forming cobalt(II) salts. The decobaltization processes are well known and described in detail in the literature. After oxidation, the mixture is separated into the organic product phase, exhaust gas, and process water. The separated process water typically has a pH value of 1.5 to 4.5 and a cobalt content between 0.5 and 2 wt%. The majority of the process water is returned to the decobalt reactor, optionally with the addition of water. The remaining portion is preferably returned to the hydroformylation reactor.

[0051] The aqueous sludge phase drawn off from the hydroformylation reactor contains, in addition to cobalt(II) salts, organic substances and cobalt carbonyl compounds. If this solution cannot be used as is, it is advantageous to feed it into the descobalt reactor together with the hydroformylation mixture.

[0052] Preferably, the aqueous bottom effluent can be extracted with feed olefin before further use or processing, whereby a portion of the cobalt carbonyls and organic substances contained therein are absorbed by the olefin phase. The olefin phase loaded with cobalt carbonyls is then transferred to [202400226] abroad

[0053] 7

[0054] The hydroformylation reactor was operated. Extraction is preferably carried out countercurrently in conventional technical extraction equipment, for example in a packed column. The extraction temperature can range between 20 and 220 °C. The pressure in the reaction column can range from 1 to 400 bar.

[0055] The organic reaction mixture obtained after the separation of the cobalt carbonyls is processed using known methods. For example, it can be separated by distillation into a hydrocarbon fraction, which may contain unreacted olefins, and into aldehydes, other valuable products, and other substances. The hydrocarbon fraction containing unreacted olefins can be partially recycled to the same hydroformylation reaction according to the invention or reacted in a further hydroformylation reaction, which may also be carried out according to the invention. The aldehydes obtained can be used as such or can serve as starting materials for the production of other substances, for example, alcohols, carboxylic acids, amines, nitriles, or aldol condensation products.

[0056] The core of the inventive method is the use of an APC control system with at least three controlled variables A, B and C, of ​​which

[0057] I) the controlled variable A represents the target controlled variable,

[0058] II) a setpoint is specified for the controlled variable B and the controlled variable B is kept constant around the setpoint, and

[0059] III) for the controlled variable C, an unchanging limit value (setpoint) is set which must not be exceeded or fallen below.

[0060] In the context of the present invention, APC control refers to a process control system. APC stands for "Advanced Process Control." With APC control, process parameters such as pressure, temperature, concentration, flow rate, etc., are measured and analyzed, if necessary continuously. Based on this analysis, the process parameters can be influenced and controlled in relation to one another in such a way as to reduce undesirable fluctuations in the process parameters and achieve optimal conditions, taking into account any specified requirements.

[0061] According to assumption I), the controlled variable A is the target controlled variable. This means that either a specific target value is specified for the controlled variable, which is to be reached or maintained, or that a specific target range is targeted for this controlled variable, i.e., the controlled variable assumes a value that lies within a predetermined range of values.

[0062] The controlled variable A, within the scope of the present invention, is the reaction conversion, the yield, or the input factor. The reaction conversion is the proportion of the original starting material used.

[0063] 8

[0064] which was converted by the process. The yield is the quotient of the amount of substance obtained in the product and the theoretically maximum possible amount of product. The input factor is defined as the mass of olefin required to produce the mass of the desired product (aldehyde + alcohol already formed during the hydroformylation). The controlled variable A is thus a measure of the efficiency of the hydroformylation process under consideration.

[0065] According to a preferred embodiment of the present invention, the controlled variable A is the reaction conversion rate. A specific target value can be specified for the reaction conversion rate, preferably an existing or achievable conversion rate of 50 to 95%, more preferably 60 to 90%. Alternatively, the controlled variable A can be specified to achieve the highest possible conversion rate, i.e., a conversion rate of 100% is targeted. Preferably, a target value range for the reaction conversion rate in the range of 50 to 95%, more preferably 60 to 90%, is specified.

[0066] The reaction conversion is preferably measured during the process according to the invention using inline analysis. This means that the reaction conversion is determined continuously or at certain time intervals using an analytical method integrated within the reaction system. Spectroscopic or chromatographic methods, particularly a spectroscopic method, are preferably used to determine the reaction conversion. The measurement method should be sufficiently fast to allow for a sufficiently rapid response of the control measures. In a particularly preferred embodiment of the present invention, the reaction conversion is determined during the process using Raman spectroscopy or NIR spectroscopy, preferably Raman spectroscopy.

[0067] According to condition II), a setpoint is specified for the controlled variable B, and the controlled variable B is kept constant around this setpoint. The setpoint can be variable, i.e., it can change during the process, but the value may deviate from the original setpoint by a maximum of + / - 10%.

[0068] In the context of the present invention, the controlled variable B is the level of the aqueous bottom phase in the at least one reactor. The level of the aqueous bottom phase in the hydroformylation reactor is therefore kept constant or nearly constant. This means that the phase boundary between the lower aqueous phase and the overlying organic phase assumes a level during the process according to the invention, the height of which preferably fluctuates by less than ±10% around the setpoint. This average level of the aqueous bottom phase can be located below, above, or at the level of the outlet opening of the mixing nozzle through which the reactants are introduced into the reactor. The phase boundary can be located 0 to 1 m, preferably 0 to 0.5 m, and particularly preferably 0 to 0.2 m above or below the outlet opening of the mixing nozzle. The proportion of aqueous bottom phase in the at least one reactor is preferably 0.5 to 20%, and particularly preferably 1 to 10% of the liquid reactor contents.202400226 Abroad.

[0069] 9

[0070] Determining the level of the aqueous sludge phase is challenging because it must be performed during full operation with the reactor closed. Therefore, the level of the aqueous sludge phase in the reactor is preferably determined by radioactive level measurement or by fiber optic temperature measurement, preferably by fiber optic temperature measurement. Fiber optic temperature measurement allows for the acquisition of numerous measurement points vertically along the reactor wall with spatial and temporal resolution. The level of the aqueous sludge phase is calculated from the temperature profile of the fiber optic temperature measurement and can be determined with an accuracy of <50 mm. This calculation is based on the fact that the temperature of the aqueous sludge phase is lower than the temperature of the organic phase.

[0071] According to requirement III), a fixed limit value (setpoint) is defined for the controlled variable C, which must not be exceeded or fallen below. Preventing the limit value from being exceeded or fallen below is a necessary condition for the success of the method according to the invention. In a preferred embodiment, a fixed upper limit value (setpoint) is defined for the controlled variable C, which must not be exceeded.

[0072] Within the scope of the present invention, the controlled variable C is the reaction temperature in the reactor. Preferably, an upper limit (setpoint) for the reaction temperature in the reactor is defined, which must not be exceeded. The limit for the reaction temperature is preferably in the range of 100 to 200 °C, more preferably in the range of 130 to 195 °C, and particularly preferably in the range of 180 to 195 °C. The reaction temperature is preferably also determined by means of fiber optic temperature measurement. If the limit for the temperature is exceeded, there is a risk of metallic cobalt precipitation and, consequently, degradation of the catalyst system.

[0073] In a particularly preferred embodiment, the controlled variable A is the reaction conversion, the controlled variable B is the level of the aqueous sump phase, and the controlled variable C is the reaction temperature.

[0074] The APC control is therefore used in the present procedure to simultaneously fulfill all three conditions I), II), and III). Preferably, the three controlled variables A, B, and C are coordinated such that all conditions I), II), and III) have equal priority. Thus, no single controlled variable is given preferential treatment. At the same time, all three controlled variables can be changed under conditions I), II), and III) to influence the other controlled variables. This can be illustrated by the following example:

[0075] Under the reaction conditions of hydroformylation, the catalyst complex tends to decompose into cobalt oxide and metallic cobalt. This decomposition is particularly favored by high temperatures. A higher catalyst concentration, achieved by changing the level of the aqueous sump phase, lowers the reaction temperature, which in turn reduces the decomposition of the catalyst complex. Furthermore, a lower reaction temperature results in the formation of fewer undesirable byproducts. The product composition, especially the conversion, is measured by inline analysis. Inline analysis provides a direct answer to [202400226 foreign].

[0076] 10

[0077] Changes in water level and / or temperature can be adjusted here using the APC control to improve turnover.

[0078] Fig. 1 schematically shows an embodiment of the present invention. An aqueous bottom phase (6) and an organic phase (7) are present in the reactor (1). Hydroformylation takes place in the organic phase (7). The catalyst passes from the aqueous bottom phase (6) into the organic phase (7) via the interface. Synthesis gas (3), aqueous cobalt solution (4), and the feed olefins or olefin mixture (5) are continuously supplied to the reactor. A portion (8) of the aqueous phase (6) and a portion (9) of the organic phase (7) are continuously drawn off via the respective outlets. In the example shown here, a fiber optic temperature measuring device (2) is provided to determine the level of the aqueous bottom phase (LIC). The temperature (TIC) is also determined using this fiber optic temperature measuring device (2). The reaction conversion is determined by means of inline analysis (QIC).

[0079] The present invention is explained with reference to the following example. This example is only one of many possible embodiments and is not to be understood as limiting.

[0080] Example

[0081] Hydroformylation of di-n-butene (DnB) was carried out in a cascaded bubble column reactor in the presence of an unmodified cobalt catalyst. The following operating parameters were used.

[0082]

[0083] • determined using inline analysis (Raman spectroscopy)

[0084] The APC control was set to ensure a reaction conversion of 79% with constant DnB feed and constant reactor pressure. This resulted in the following time profile:

[0085] • Start:

[0086] Reaction conversion at 82% (see second column of the table);

[0087] • After approximately 24 hours:

[0088] The reaction temperature was lowered from 189°C to 187°C; consequently, the level of the aqueous phase increased (by less than +10%), thereby reducing the amount of catalyst from 1015 to 970 kg / h, which in turn lowered the reaction conversion to 80% (see third column of the table); 202400226 Abroad

[0089] 11

[0090] After approximately 37 hours:

[0091] The reaction temperature was reduced from 187°C to 186°C; as a result, the level of the aqueous phase increased (less than +10%), thereby reducing the amount of catalyst from 970 to 930 kg / h, which in turn reduced the reaction conversion to 79% (see fourth column of the table).

[0092]

[0093] It has been shown that the claimed APC regulation works and that all three requirements are met simultaneously. 202400226 Abroad

[0094] 12

[0095] Reference symbol list

[0096] 1 reactor

[0097] 2 Fiber optic temperature measuring device 3 Synthesis gas supply

[0098] 4. Add aqueous cobalt solution

[0099] 5. Feeding of working olefins / olefin mixture

[0100] 6. Aqueous swamp phase

[0101] 7 Organic Phase

[0102] 8 Outlet aqueous phase

[0103] 9 Outlet organic phase

[0104] QIC Inline Analytics Reaction Turnover

[0105] LIC Calculated level of the aqueous sump phase TIC Temperature measurement

Claims

202400226 Abroad 13 Patent claims 1. A process for the continuous hydroformylation of olefins with 5 to 24 carbon atoms, preferably 8 to 16 carbon atoms, with synthesis gas in the presence of a modified or unmodified, preferably an unmodified, cobalt catalyst in at least one reactor, wherein The olefins in the form of an olefin stream, an aqueous cobalt salt solution and the synthesis gas are continuously fed to at least one reactor, in which at least one reactor contains an aqueous sludge phase and an organic phase located above the aqueous sludge phase, wherein the organic phase contains the reaction products, and Continuously, a portion of the aqueous sludge phase and a portion of the organic phase are taken from at least one reactor, whereby The procedure uses an APC control system with at least three controlled variables A, B and C, whereby the following conditions I), II) and III) are met during the procedure, wherein I) the controlled variable A is the reaction conversion, the yield or the input factor and represents the target controlled variable, wherein either a specific target value or a specific range of target values ​​is specified for the controlled variable; II) for the controlled variable B is the state of the aqueous sump phase, for which a setpoint is specified and the controlled variable B is kept constant around the setpoint, and III) for the controlled variable C, the reaction temperature in which there is at least one reactor, for which an unchanging limit value (setpoint) is set which must not be exceeded or fallen below.

2. The method according to claim 1, wherein the controlled variable A is the reaction conversion.

3. The method of claim 2, wherein the reaction conversion during the method is determined by means of inline analysis.

4. The method of claim 3, wherein spectroscopic or chromatographic methods, preferably a spectroscopic method, are used to determine the reaction conversion. 202400226 Abroad 14 5. Method according to claim 4, wherein Raman spectroscopy or NIR spectroscopy, preferably Raman spectroscopy, is used to determine the reaction conversion.

6. Method according to one of the preceding claims, wherein a target value range for the reaction conversion is specified in the range of 50 to 95%, preferably 60 to 90%.

7. Method according to one of the preceding claims, wherein the level of the aqueous sump phase in the reactor is determined by means of radioactive level measurement or by means of fiber optic temperature measurement, preferably by means of fiber optic temperature measurement.

8. Method according to claim 7, wherein the level of the aqueous sump phase in the reactor is determined by means of fiber optic temperature measurement.

9. A method according to one of the preceding claims, wherein an upper limit (setpoint) for the reaction temperature in the reactor is defined, which must not be exceeded.

10. The method according to claim 9, wherein the limit for the reaction temperature is in the range of 100 to 200 °C.

11. Method according to claim 9 or 10, wherein the limit for the reaction temperature is preferably in the range of 130 to 195 °C.

12. Method according to any one of claims 9 to 11, wherein the limit for the reaction temperature is in the range of 180 to 195 °C.

13. A method according to any of the preceding claims, wherein mixtures of isomeric octenes (C8 olefins), nonenes (C9 olefins), dodecenes (C12 olefins) or hexadecenes (C16 olefins) are used as olefins.

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