Raw-material supply system and raw-material supply method

A raw-material supply system for pyrolyzing waste plastic containing polyvinyl chloride and polyethylene terephthalate, the raw-material supply system comprising:

• a slaked-lime (Ca(OH)2 supply device configured to feed slaked lime to the waste plastic;
• an operation controller configured to instruct the slaked-lime supply device to feed the slaked lime to the waste plastic, the slaked lime to be fed having a number of moles that is 1 to 4 times a total number of moles of the polyvinyl chloride and the polyethylene terephthalate in the waste plastic;
• a melting dechlorination device configured to dechlorinate the polyvinyl chloride and hydrolyze the polyethylene terephthalate by mixing the waste plastic and the slaked lime while heating the waste plastic and the slaked lime;
• a degassing hopper coupled to the melting dechlorination device and configured to store the waste plastic that has been melted by the melting dechlorination device;
• and
• a raw-material supply device configured to deliver the molten waste plastic from the degassing hopper to a pyrolysis furnace,
• wherein the pyrolysis furnace comprises a pyrolysis furnace of a fluidized-bed furnace,
• the fluidized-bed furnace includes the pyrolysis furnace and a medium regeneration furnace containing a fluidized medium that circulates between the pyrolysis furnace and the medium regeneration furnace,
• the raw-material supply system further comprises a fluidized-medium transfer line configured to deliver a part of the fluidized medium from the medium regeneration furnace to the melting dechlorination device, and
• the part of the fluidized medium constitutes a heat source of the melting dechlorination device.