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 degrees 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 degrees 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.