PROCESS FOR UPGRADING FISCHER-TROPSCH SYNCRUDE USING THERMAL CRACKING AND OLIGOMERIZATION

摘要

A process for upgrading a Fischer-Tropsch feedstock which comprises (a) recovering from a Fischer-Tropsch reactor (4) a Fischer-Tropsch wax fraction (6) and a Fischer-Tropsch condensate fraction (8), wherein the Fischer-Tropsch condensate fraction contains alcohols boiling below about 370 °C; (b) contacting the Fischer-Tropsch condensate fraction (8) with a dehydration catalyst in a dehydration zone (14) under dehydration conditions pre-selected to convert at least some of the alcohols present in said fraction into olefins and recovering a first intermediate effluent (16) from said dehydration zone; (c) pyrolyzing the paraffins in the Fischer-Tropsch wax fraction (6) in a thermal cracking zone (10) under thermal cracking conditions pre-selected to crack the Fischer-Tropsch wax molecules to form olefins and collecting a second intermediate effluent (12) from the thermal cracking zone (10); (d) passing the first and second intermediate effluents (12, 16) recovered from steps (b) and (c) to an oligomerization zone (22) containing an oligomerization catalyst under oligomerization conditions to form an oligomerization mixture (26) having a higher molecular weight than either of said first and second intermediate effluent (12, 16); (e) hydrofinishing the oligomerization mixture (26) in a hydrofinishing zone (28); and (f) recovering from the hydrofiniching zone (28) a C10 plus hydrocarbon product, most preferably a lubricating base oil.