Abstract
A coal liquefaction residue (CLR) was impregnated into coals at 200-250°C and was pyrolyzed by using three types of reactors. Effectiveness of impregnation was evaluated by the improvement of CLR handling and by the stabilization fragment radicals of coal with donatable hydrogen contained in CLR.
When the CLR/coal weight ratio was less than 30/70 for Wandoan coal and less than 50/50 for Morwell brown coal, no agglomerated particles were formed in coal/CLR composites. A good contact between coals and CLR at the molecular level was confirmed from the results of solvent extraction and SEM observation of impregnated coals.
In pyrolysis, negative synergism was found in the yield of hydrogen gas, indicating the hydrogen transfer from CLR to coal. The amount of transferred hydrogen normalized by the coal mass was 4.5mol/kg coal at a CLR/coal ratio of 70/30. The yields of hydrocarbon gases and inorganic gases also showed negative synergism. This result suggests that the CLR suppressed the fromation of cross-links accompanied by the evolution of these gases. Hydrogen transfer and suppression of cross-linking reactions contributed to the increase in yield of light aromatics such as BTX and PCX.
