PRODUCTION OF MIDDLE DISTILLATE HYDROCARBON COMPOSITION

A process for the preparation of a middle distillate hydrocarbon composition from ethylene, wherein said process comprises the following steps: (a) feeding an ethylene composition in to an oligomerisation reaction zone containing a supported nickel oligomerisation catalyst to form an oligomerisation product A, wherein the oligomerisation reaction is operated at a temperature in the range of from 30 to 300 °C and a pressure of at least 10 bara; (b) separating a light products stream B, a middle distillate product stream C and a heavy products stream D from oligomerisation product A, wherein the light product stream B comprises the fraction of oligomerisation product A which boils in the C2-C8 mono-olefin boiling range and the middle distillate product stream C comprises a fraction of oligomerisation product A which boils above the boiling range of the light product stream B and below the boiling range of the heavy products stream D, and wherein the heavy product stream D comprises the fraction of oligomerisation product A which boils above the C22 mono-olefin boiling range; (c) recycling a portion of the light products stream B to the oligomerisation reaction zone of step (a) of the process; (d) feeding the heavy product stream D and a portion of the light products stream B in to an olefin metathesis reaction zone to produce a metathesis product stream E; (e) separating a middle distillate product F from the metathesis product stream E; and (f) hydrogenating the middle distillate product stream C, wherein the middle distillate hydrocarbon composition comprises at least a portion of the hydrogenated middle distillate product stream C and at least a portion of the middle distillate product F. La présente invention concerne un procédé de préparation d'une composition d'hydrocarbures de distillat moyen à partir d'éthylène, ledit procédé comprenant les étapes suivantes consistant à : (a) charger une composition d'éthylène dans une zone de réaction d'oligomérisation contenant un catalyseur d'oligomérisation de nickel supporté pour former un produit d'oligomérisation A, la réaction d'oligomérisation étant activée à une température comprise dans la plage de 30 °C à 300 °C et une pression d'au moins 10 bara ; (b) séparer un flux de produits légers B, un flux de produits de distillat moyen C et un flux de produits lourds D du produit d'oligomérisation A, le flux de produits légers B comprenant la fraction du produit d'oligomérisation A qui bout dans la plage d'ébulli