Method for catalytically cracking waste plastics and apparatus for catalytically cracking waste plastics

A method for catalytically decomposing solid waste plastics comprising:

• externally heating a horizontal-type reaction vessel, formed to a cylindrical shape, including a rotary-vane type agitator in the interior thereof, and containing a mixture of a granular FCC waste catalyst and a granular Ca compound, the mixture thereby being preliminary heated to a temperature range from 350° C. to 435° C., wherein the amount of the FCC waste catalyst is 20 to 60 vol % of the capacity of the reaction vessel, and the Ca compound is present in an amount of 15 to 50 parts by mass with respect to 100 parts by mass of the FCC waste catalyst,
• adding and mixing/agitating granular or flake-shaped solid waste plastics by the agitator into the mixture of the heated granular FCC waste catalyst and the Ca compound and allowing the solid waste plastics to be in direct contact with the mixture at a temperature range from 350° C. to 435° C.,
• processing the solid waste plastics inside the reaction vessel at a flow rate of 0.2 g to 10 g of the solid waste plastics per gram of the catalyst per hour and heating while coating the heated granular FCC waste catalyst onto the surface of the solid waste plastics to cause decomposition and gasification of the solid waste plastics via an ion reaction, and producing gaseous hydrocarbons, wherein the proportion of the hydrocarbons having a carbon number of 5 to 15 is greater than the proportion of hydrocarbons having a carbon number of 16 to 24, wherein the processing of the solid waste plastics inside the reaction vessel is conducted in the absence of petroleum oils, and
• removing the gaseous hydrocarbons from the reaction vessel by a carrier gas.