Abstract: The present invention relates to a plant for oligomerizing ethylene to produce oligomerized alpha-olefins, with production of a fouling by-product in the form of a deposit, said plant comprising a reaction section comprising: —a reactor (c) for two-phase gas/liquid or single-phase all-liquid oligomerization proceeding from an optional solvent, an oligomerization catalyst and ethylene, and —cooling means associated with said reactor in the form of at least one cooling circuit external to the reactor and/or in the form of a jacket of the walls of the reactor. Packings are disposed in the reaction section in order to increase the contact surface area per unit volume that is accessible to the deposition of the byproduct.

Abstract: The present invention relates to a process for treating an effluent obtained from an oligomerization step in a vaporization step. In particular, the oligomerization step is a step for dimerization of ethylene to 1-butene with a nickel-based catalytic system.