The Effects of Reaction Temperature and Time on Coprocessing of Coal and Plastics

Abstract

It is difficult to recycle effectively the waste plastic mixture. Plastics were employed in the coal liquefaction process as a source of hydrogen. Mixture of a coal and three kinds of plastics was liquefied by using a non-hydrogen donor solvent, and the effects of reaction temperature and time on the coprocessing were investigated.
Radicals are derived from coal at about 300°C, and those attack plastics. Therefore, the possibility of a lowering of the initial reaction temperature on this coprocessing was suggested. The combination of radicals from coal and plastics produced radicals having large molecular weight, so the yield of residue increased. The residue decomposed with the increase of the reaction time. As the reaction temperature increased, the decomposition rate of residue was becoming faster. However, the over-decomposition of plastic radicals occurred, and the interaction of radicals from plastics and coal would be inhibited. The result was linked to the increase of the final yield of residue. In conclusion, the increase of reaction time rather than that of reaction temperature was effective for the appearance of interaction of coal and plastics to bring about the decrease of residue.