Thermal Upgrading of Fischer−Tropsch Olefins

Abstract

Thermal oligomerization is a radical based conversion process. It offers specific advantages to linear olefinic feed with a high α-olefin content, like primary Fischer−Tropsch products. Thermal oligomerization of C4−C14 Fischer−Tropsch feed materials has been investigated over the temperature range 320−400 °C. Motor gasoline, distillate, and lubricating oil quality was determined by the feed used, and operating conditions had only a minor influence. Good quality distillate (cetane ≥ 54) and lubricating oil (viscosity index of 100) could be produced, while the naphtha was suitable for chemical applications, like plasticizer alcohols production. Oxygenates present in the Fischer−Tropsch product had little influence on the process. Carbon formation was about 400 μg·g-1. Prospects for commercial application was discussed and is limited to an olefin-rich refining environment, where feed-specific advantages can be used to offset the disadvantage of a slow reaction rate (0.1 mol·s-1·m-3).