Kinetics of Thermal and Catalytic Coal Liquefaction with Plastic-Derived Liquids as Solvent

Results of a kinetic study of thermal and catalytic (Fe impregnated on coal) liquefaction of DECS-6 coal with plastic-derived liquids (PDL) as solvent have been obtained. The experimental work was conducted in 27-cm 3 horizontally shaken microreactors at temperatures of 360−400 °C with isothermal reaction times ranging from 0 to 180 min. The reaction pressure was about 2000 psig H 2, and the solvent-to-coal weight ratio was 2:1. Experimental data were correlated by a kinetic model which assumed the reaction pathways: coal to preasphaltenes, coal to asphaltenes, coal to gas + oil, preasphaltenes to asphaltenes, preasphaltenes to gas + oil, and asphaltenes to gas + oil. It was shown that this reaction model fit experimental data reasonably well at the conditions used, and the six rate constants exhibited Arrhenius-type temperature dependence. Some reactions were also carried out at a higher temperature (420 °C) to validate the model at reaction conditions other than conditions used for obtaining the kinetic parameters. Direct coal liquefaction reactions were predominant for both thermal and catalytic DECS-6 coal liquefaction with PDL as solvent, although the catalyst promoted consecutive reactions to a larger extent.