Liquefaction of Dibenzyl (DB) as a coal model compound, model plastics (PP, PS, high-density PE and their mixture), and the mixture of DB and the plastics were carried out at 430℃ for 60min using solvent with or without red mud/sulfur catalyst under 7MPa initial pressure of hydrogen or nitrogen. PE decomposition, which proceeds as radical chain reaction, was inhibited with the increase in hydrogen donorbility of solvent, and addition of the catalyst, resulting in lower conversion to hexane-& THF-soluble and lower oil yield. However, conversion of PE to THFS increased with the coexistence of DB, PP and PS. It was suggested that radicals from the coexisting reactants attacked PE, giving acceleration of PE cracking. The accelerating effect was largest in case of the coexistence of PS.
