Under the hydrogen-donative conditions using tetralin solvent and hydrogen gas, the coprocessing of coal and three kinds of plastics, such as high-density polyethylene, polypropylene and polystyrene, yielded a large amount of oil compared with the individual reactions. On the other hand, the coprocessing under the pyrolysis conditions using decalin solvent and nitrogen gas brought an increase in the yield of volatile matter and decreases in the yield of gas and oil. These results suggested that the coprocessing stabilizes the coal radicals and the plastic radicals so that the polymerization and the decomposition of plastic radicals are suppressed.
