Process for the oligomerization of olefins employing a cleaning device

A process for oligomerization of ethylene into alpha-olefins, comprising:

• oligomerizing the ethylene in a reaction section (1) comprising a reactor (10), in the presence of a catalyst, and optionally a diluent, to produce a reaction effluent,
• deactivating the catalyst contained in the reaction effluent,
• evaporating in an evaporation section (2) the reaction effluent in order to separate a portion of the reactant effluent from the deactivated catalyst, and
• separating in a separation section (3) products contained in the reaction effluent,
• said reactor being provided with at least one cooling loop (100 a/b, 101 a/b, 102a/b), by which reaction medium is caused to move through at least two switchable heat exchangers which are capable of being connected to the at least one cooling loop in a manner such that when at least one heat exchanger is operatively connected to the at least one cooling loop, the other heat exchanger is disconnected and undergoes cleaning by a cleaning device in which a cleaning solvent which is capable of cleaning said heat exchanger is caused to move in a loop of solvent of the cleaning device, the cleaning device comprising:
• a cleaning solvent storage drum (40);
• a heat exchanger (43) heating the cleaning solvent to a temperature above 130° C. in a manner such as to allow the polymer deposited in the disconnected heat exchanger to be dissolved thereby producing a charged solvent;
• and
• a recirculation pump (42) moving the cleaning solvent in the loop of solvent of the cleaning device through the cleaning solvent storage drum (40), the heat exchanger (43) and the disconnected heat exchanger which is to be cleaned,
• wherein the process further comprises sending at least a portion of cleaning solvent obtained from the loop of solvent of the cleaning device to the evaporation section (2).