US Patent 7345210 Blending for density specifications using Fischer-Tropsch diesel fuel

The present invention includes a method for adjusting a fluid density. In one embodiment, a method for upgrading a petroleum-derived hydrocarbonaceous fraction comprises providing a synthetically-derived hydrocarbonaceous fraction, wherein the synthetically-derived hydrocarbonaceous fraction is derived from synthesis gas, and further wherein the synthetically-derived hydrocarbonaceous fraction and the petroleum-derived hydrocarbonaceous fraction have a difference in density at 15° C. of at least about 60 kg/m3; and blending both fractions so as to form a blend suitable for use as a diesel or diesel blendstock, wherein the blend has a density at 15° C. equal to or more than about 800 kg/m3; alternatively or additionally, equal to or less than about 860 kg/m3. The blending is also effective in reducing the sulfur content of the petroleum-derived hydrocarbonaceous fraction. In preferred embodiments, the synthetically-derived hydrocarbonaceous fraction is a Fischer-Tropsch diesel.