2006 Volume 85 Issue 3 Pages 204-207
The coprocessing with coal is one of the beneficial technologies to convert waste plastics into alterna-tive liquid hydrocarbon for fuel oil and chemical feedstock. The waste plastics having high H/C ratio are expected to play the role of hydrogen source. On the other hand, the waste plastics include chlorine-contain-ing plastic such as polyvinyl chloride (PVC). Hydrogen chloride generated from pyrolysis of PVC causes the problems such as the corrosion of equipment. In the coprocessing reaction, it is expected that the hydrogen chloride is captured by the minerals in coal.
In this paper, the influence of PVC on the coprocessing with Wyoming subbituminous coal and the mixture of high density polyethylene, polypropylene, polystyrene, and PVC was investigated under decalin solvent.
A part of hydrogen chloride generated from PVC was fixed as chlorides by the minerals in coal, but the rest formed chlorinated organic compounds. These reactions occured competitively. When a sufficient amount of hydrogen chloride was not captured, the chain reactions of polymer radicals were inhibited by chlorine radical. This inhibitation resulted in the increase of heavy oil yield. To avoid it, the optimization of the raito of coal and plastics was desired.