Process for preparing naphtha and middle distillate fractions

摘要

The invention provides a process for preparing one or more naphtha fractions and one or more middle distillate fractions, the process comprising the steps of:
(a) providing a Fischer-Tropsch hydrocarbons stream;
(b) subjecting the Fischer-Tropsch hydrocarbons stream as provided in step (a) to a thermal conversion step to obtain a converted hydrocarbon stream comprising paraffins and olefins;
(c) separating at least part of the converted hydrocarbon stream as obtained in step (b) into a first fraction having a boiling point below 380°C and a second fraction having a boiling point which is higher than 300°C;
(d) hydrogenating at least part of the first fraction having a boiling point below 380 °C as obtained in step (c) to obtain a hydrogenated fraction having a boiling point below 380°C;
(e) catalytic dewaxing at least part of the hydrogenated fraction having a boiling point below 380 °C as obtained in step (d) to obtain an at least partially isomerised product; and
(f) separating at least part of the at least partially isomerised product as obtained in step (e) into one or more naphtha fractions and one or more middle distillate fractions.