Process for producing propene and/or butene oligomers

Claim 1

A process for producing at least one hydrocarbon-soluble oligomer, while decreasing or suppressing the formation of black sticky catalyst deposit formation on reactor walls, which process comprises: (a) feeding a liquid hydrocarbon charge comprising at least one olefinic hydrocarbon selected from propene and the butenes with an oligomerization catalyst dispersed in said charge into at least one elongated, substantially cylindrical reaction zone, at an hourly feed rate of at least 5 liters of said liquid charge per liter of reaction space in said reaction zone and at an average residence time of said olefinic hydrocarbon from 0.5 to 10 hours, said feeding being effected at least partly in a tangential direction, to thereby give to said liquid charge a circular motion in the reaction zone, and said reaction zone being maintained at liquid phase oligomerization conditions of temperature and pressure, said oligomerization catalyst being a material obtained by reacting at least one nickel compound with at least one hydrocarbyl aluminum halide, (b) displacing said liquid hydrocarbon charge axially in said reaction zone, thereby adding a translation motion to the circular motion of said charge, and (c) discharging a liquid stream from said reaction zone, said discharged stream consisting essentially of the whole unfractionated reaction product and comprising all hydrocarbon-soluble oligomer formed and all unreacted hydrocarbon, said process resulting in decreased or suppressed catalyst deposit formation.