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Dokumentenidentifikation EP1780189 14.06.2007
EP-Veröffentlichungsnummer 0001780189
Titel Oligomerisierung von Ethylene
Anmelder Linde AG, 65189 Wiesbaden, DE;
Saudi Basic Industries Corp., Riyadh, SA
Erfinder Schneider, Richard, 82449 Uffing, DE;
Fritz, Peter M., 82008 Unterhaching, DE;
Muschelknantz, Sebastian, 81479 München, DE;
Bölt, Heinz, 82515 Wolfratshausen, DE;
Ali, Talal, 11551 Riyadh, SA;
Mousa, Fuad, 11551 Riyadh, SA
Vertreter derzeit kein Vertreter bestellt
Vertragsstaaten AT, BE, BG, CH, CY, CZ, DE, DK, EE, ES, FI, FR, GB, GR, HU, IE, IS, IT, LI, LT, LU, LV, MC, NL, PL, PT, RO, SE, SI, SK, TR
Sprache des Dokument EN
EP-Anmeldetag 19.10.2005
EP-Aktenzeichen 050227792
EP-Offenlegungsdatum 02.05.2007
Veröffentlichungstag im Patentblatt 14.06.2007
IPC-Hauptklasse C07C 2/30(2006.01)A, F, I, 20070403, B, H, EP
IPC-Nebenklasse C07C 11/00(2006.01)A, L, I, 20070403, B, H, EP   

Beschreibung[en]

The present invention relates to a method for oligomerisation of ethylene to form linear alpha-olefins in an oligomerisation reactor in the presence of solvent, catalyst and co-catalyst, wherein a reaction product containing linear alpha-olefins or alpha-olefins separated from the reaction product are passed to a heat exchanger for cooling thereof.

Oligomerisation methods for preparing linear alpha-olfins are widely known in the art. This methods are easily carried out in the presence of a catalyst preferably comprising a zirconium component, such as zirconium tetraisobutyrate, and an aluminum component as activator, such as ethyl aluminum sesquichloride.

Usually, a reaction product discharged from the oligomerisation reactor may comprise solvent, catalyst, co-catalyst and liquid linear alpha-olefins. This reaction product is further processed, for example the catalyst and co-catalyst may be deactivated and removed from the alpha-olefins. Additionally, the reaction product may be passed to a heat exchanger for cooling thereof.

In the prior art, it is desirable to adjust a wall temperature of that heat exchanger to be as low as possible, as the lower the wall temperature the smaller the heat exchanger may be designed. However, it has been found that high molecular weight oligomers obtained in that reaction product (for example linear alpha-olefins having more than 20 carbon atoms) have a high tendency for plugging in heat exchangers on surfaces thereof having relatively low temperature. This may result in a reduced heat transfer efficiency in that heat exchanger.

It is therefore an object of the present invention to provide a method for oligomerisation of ethylene which overcomes the drawbacks of the prior art. Especially, a method shall be provided wherein plugging of equipment for carrying out the oligomerisation, especially, plugging of heat exchangers, may be avoided.

This object is achieved in that the wall temperature of the heat exchanger is adjusted to be higher than the pour points of the linear alpha-olefins obtained.

Preferably, wherein the reaction product comprises C4-C20+ olefins.

In one embodiment, the wall temperature is higher than about 35°C, preferably higher than about 40°C, more preferably higher than about 70°C.

Also preferred, adjustment of the wall temperature is achieved by selection of an appropriate coolant, air recirculation in an air cooler, air heating in an air cooler, or combinations thereof.

The method is preferably characterized in that the catalyst comprises a zirconium salt of organic acids, preferably having the formula ZrCl4-mXm, wherein X = OCOR or OSO3R' with R and R' being independently alkyl, alkene or phenyl, and wherein 0 < m < 4.

Finally, the co-catalyst may be at least one organoaluminum compound, preferably Al(C2H5)3, Al2Cl3(C2H5)3 Or AlCl(C2H5)2.

Surprisingly, it was found that plugging of reaction equipment, especially of the heat exchanger, may be avoided if the wall temperature of that heat exchanger is adjusted to be higher than the pour points of the linear alpha-olefins to be cooled. Additionally, the thermal efficiency of the heat exchanger may be maintained. If the method is run in the heat exchanger at a temperature higher than the pour points of the linear alpha-olefins, the linear alpha-olefins can not solidify as deposits on the surfaces of the heat exchanger.

Preferably, the wall temperature of the heat exchanger may be adjusted by selection of appropriate coolant, air recirculation in an air cooler, air heating in an air cooler, or combinations thereof. In air coolers, external air circulation in a closed section of the air cooler may be installed. A heating bundle may be installed, which can be electrically heated, or heated by means of steam, hot oil or warm water. In addition, louvers may be installed at the air inlet and / or outlet. The tube wall temperature may be kept at the envisaged level by means of a controller. In shell-and-tube heat exchangers the applicable cooling medium may be optimized, e.g. cooling water may be taken from the cold water supply header or from the warm return header. In addition a cooling water recirculation may be installed to adjust tube wall temperature.

The features disclosed in the foregoing description and in the claims may, both separately and in any combination thereof, be material for realizing the invention in divers forms thereof.


Anspruch[en]
Method for oligomerisation of ethylene to form linear alpha-olefins in an oligomerisation reactor in the presence of solvent, catalyst and co-catalyst, wherein a reaction product containing linear alpha-olefins or alpha-olefins separated from the reaction product are passed to a heat exchanger for cooling thereof, characterized in that the wall temperature of the heat exchanger is adjusted to be higher than the pour points of the linear alpha-olefins obtained. Method according to claim 1, wherein the reaction product comprises C4-C20+ olefins. Method according to claim 1 or 2, wherein the wall temperature is higher than about 35°C, preferably higher than about 40°C, more preferably higher than about 70°C. Method according to any of the preceding claims, wherein adjustment of the wall temperature is achieved by selection of an appropriate coolant, air recirculation in an air cooler, air heating in an air cooler, or combinations thereof. Method according to any of the preceding claims, wherein the catalyst comprises a zirconium salt of organic acids, preferably having the formula ZrCl4-mXm, wherein X = OCOR or OSO3R' with R and R' being independently alkyl, alkene or phenyl, and wherein 0 < m < 4. Method according to any of the preceding claims, wherein the co-catalyst is at least one organoaluminum compound, preferably Al(C2H5)3, Al2Cl3(C2H5)3 or AlCl(C2H5)2.






IPC
A Täglicher Lebensbedarf
B Arbeitsverfahren; Transportieren
C Chemie; Hüttenwesen
D Textilien; Papier
E Bauwesen; Erdbohren; Bergbau
F Maschinenbau; Beleuchtung; Heizung; Waffen; Sprengen
G Physik
H Elektrotechnik

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