Oligomerisation method using a reaction device comprising a dispersion means

A gas/liquid oligomerization reaction device, comprising:

• a reaction chamber i), of elongated shape along the vertical axis, comprising a liquid phase comprising and preferably consisting of the products of the reaction, dissolved ethylene, the catalytic system and an optional solvent, and a gas phase located above said liquid phase, comprising unreacted ethylene and also the non-condensable gases (notably methane), and
• a means for introducing ethylene ii), located in the lateral lower part of said reaction chamber, employing a means for distributing ethylene within said liquid phase of the reaction chamber,
• a means for introducing the catalytic system iii), comprising a metal catalyst, at least one activator and at least one additive, said means is located in the lower part of the reaction chamber,
• a recirculation loop iv) comprising a withdrawing means at the base (preferably at the bottom) of the reaction chamber for withdrawing a liquid fraction toward a heat exchanger enabling the cooling of said liquid, and a means for introducing said cooled liquid, said introduction being carried out in the gas phase at the top of the reaction chamber,
• characterized in that
• said introduction into the gas headspace v) is carried out via a means capable of dispersing the liquid cooled in the recirculation loop iv) in the gas headspace of the reaction chamber.