OLEFIN OLIGOMERIZATION USING EXTRACTED FEED FOR PRODUCTION OF HEAVY HYDROCARBONS

A process is disclosed for oligomerizing olefinic Fischer-Tropsch liquids to produce heavier hydrocarbons by converting olefinic feedstock containing oxygenated hydrocarbons over an acidic zeolite catalyst. The improvement comprises extracting oxygenates from the feedstock; converting the extracted feedstock in a primary stage distillate mode catalytic reactor system under low severity conditions at high pressure and moderate pressure; and recovering the oxygenates and light hydrocarbons from the primary stage for conversion in a secondary stage reactor system under high severity conditons at substantially higher temperature than the primary stage, thereby converting oxygenates and light hydrocarbons to heavier hydrocarbons.