Fischer–Tropsch fuels refinery design

Abstract

Carbon sources, such as coal, natural gas, biomass and waste, can be converted into transportation fuels by combining appropriate gasification, Fischer–Tropsch and refining technologies. Efficient refining of the Fischer–Tropsch synthesis derived syncrude requires a different approach to refinery design than commonly applied to crude oil refinery design. The design of refineries to optimise the production of on-specification motor-gasoline, jet fuel and diesel fuel respectively from both high temperature Fischer–Tropsch (HTFT) syncrude and low temperature Fischer–Tropsch (LTFT) are considered. Refinery designs are presented for the production of motor-gasoline and jet fuel with better than 50% yield (better than 70% selectivity on transportation fuel), without resorting to very complex designs. Only diesel fuel refining presented a problem, since the production of on-specification EN590:2004 diesel fuel is limited by a Fischer–Tropsch specific cetane-density-yield trade-off. The compound classes that are required to produce diesel fuel in high yield that meet both minimum cetane number and minimum density requirements are not abundant in Fischer–Tropsch syncrude. Refinery designs for diesel fuel production was limited to a yield of less than 25% EN 590 : 2004 compliant diesel fuel. This yield restriction does not apply when diesel fuel specifications do not have a minimum density requirement.