There are mainly four pathways to get liquid fuels from the coal including the direct liquefaction process, the Fischer-Tropsch process, coal-tar refining, and pyrolysis process. The characteristics of these four processed have been described. As the first two pathways are considered to be promising, the characteristics of these two types of coal-based jet fuels are discussed and the component characteristics of coal-based synthesis fuels are investigated, respectively. The component characteristics of coal-based jet fuels are compared with the traditional petroleum-based jet fuels. There are large differences between the properties of the coal-based jet fuel via direct and indirect liquefaction pathways. Comparing with the conventional petroleum-based jet fuel, the coal-based jet fuel via direct liquefaction pathway has the higher aromatics content, while the fuel via indirect pathway (F-T process) has more paraffin and nearly no naphthenes or aromatics. In additional, the carbon numbers of the coal-based synthesis jet fuels are compared with the conventional petroleum-based jet fuel.
Development of an extruder-feeder biomass direct liquefaction process. Volume 2, Parts 4--8: Final report