We've been investigating the effective use of coal liquefaction residue. On the other hand the disposal of waste plastic is important environmental problem in Japan. Therefore thermal and catalytic cracking of the residue with polyethylene has been studied. Conversion of thermal cracking of the mixture showed almost no synergistic effect in the present conditions. Better conversion and oil quality were obtained in the presence of hydrogen than nitrogen. Catalytic cracking with zeolite F-9 or HZSM-5 gave higher conversion and oil yield than thermal cracking. Using tetralin as solvent improved the conversion of both thermal and catalytic cracking.
