TRANSPORT FUELS FROM 2-STAGE COAL-LIQUEFACTION

Four Spanish lignites and their vitrinite concentrates were evaluated for coal liquefaction. Correlationships between the content of vitrini te and conversion in direct liquefaction were observed for the lignite s but not for the vitrinite concentrates. The most reactive of the fou r coals was processed in two-stage liquefaction at a higher scale. Fir st-stage coal liquefaction was carried out in a continuous unit at Cla usthal Universitat at a temperature of 400-degrees-C at 20 MPa hydroge n pressure and with anthracene oil as a solvent. The coal conversion o btained was 75.41% being 3.79% gases, 2.58% primary condensate and 69. 04% heavy liquids. A hydroprocessing unit was built at the Instituto d e Carboqumica for the second-stage coal liquefaction. Whole and deasph alted liquids from the first-stage liquefaction were processed at 450- degrees-C and 10 MPa hydrogen pressure, with two commercial catalysts: Harshaw HT-400E (Co-Mo/Al2O3) and HT-500E (Ni-Mo/Al2O3). The effects of liquid hourly space velocity (LHSV), temperature, gas/liquid ratio and catalyst on the heteroatom liquids, and levels of 5 ppm of nitroge n and 52 ppm of sulphur were reached at 450-degrees-C, 10 MPa hydrogen pressure, 0.08 kg H-2/kg feedstock and with Harshaw HT-500E catalyst. The liquids obtained were hydroprocessed again at 420-degrees-C, 10 M Pa hydrogen pressure and 0.06 kg H2/kg feedstock to hydrogenate the ar omatic structures. In these conditions, the aromaticity was reduced co nsiderably, and 39% of naphtas and 35% of keroseno fractions were obta ined.