Fuel-Blending Stocks from the Hydrotreatment of a Distillate Formed by Direct Coal Liquefaction

The direct liquefaction of coal in the iron-catalyzed Suplex process was evaluated as a technology complementary to Fischer−Tropsch synthesis. A distinguishing feature of the Suplex process, from other direct liquefaction processes, is the use of a combination of light- and heavy-oil fractions as the slurrying solvent. This results in a product slate with a small residue fraction, a distillate/naphtha mass ratio of 6, and a 65.8 mass % yield of liquid fuel product on a dry, ash-free coal basis. The densities of the resulting naphtha (C5−200 °C) and distillate (200−400 °C) fractions from the hydroprocessing of the straight-run Suplex distillate fraction were high (0.86 and 1.04 kg/L, respectively). The aromaticity of the distillate fraction was found to be typical of coal liquefaction liquids, at 60−65%, with a Ramsbottom carbon residue content of 0.38 mass %. Hydrotreatment of the distillate fraction under severe conditions (200 °C, 20.3 MPa, and 0.41 gfeed h-1 gcatalyst-1) with a NiMo/Al2O3 catalyst gave...