Process for Polymerising or Oligomerising a Hydrocarbon

A hydrocarbon polymerisation or oligomerisation reactor which includes:

• a reactor vessel defining a liquid phase zone below a head space zone for holding a bulk liquid phase comprising polymeric or oligomeric product in the liquid phase zone;
• a hydrocarbon reactant inlet at a low level leading into the liquid phase zone, the inlet having at least one hydrocarbon reactant inlet nozzle aimed at an impingement surface provided inside, or defining, the liquid phase zone such that in use a localised area of high turbulence is created by the injection of a hydrocarbon reactant through the hydrocarbon reactant inlet nozzle onto the impingement surface, or said at least one hydrocarbon reactant inlet nozzle being aimed at another fluid stream inlet nozzle so that in use a localised area of high turbulence is created by the injection of a hydrocarbon reactant through said at least one hydrocarbon reactant inlet nozzle into impinging contact with a fluid stream being injected through said another fluid stream inlet nozzle;
• and
• a gaseous components outlet leading from the head space zone in use through which gaseous components collecting in the head space zone are withdrawn.