RECOVERY METHOD OF STYRENE MONOMER FROM WASTE POLYSTYRENE BY NOVEL PYROLYSIS PROCESS, FOR REMOVING INSOLUBLE MATERIALS AND CONTROLLING A MOLECULAR WEIGHT

摘要

PURPOSE: A method for recovering a styrene monomer from the waste polystyrene by using a novel pyrolysis process is provided, to obtain a styrene monomer in a high yield by improving the reaction velocity by the pretreatment for removing insoluble materials and controlling a molecular weight. CONSTITUTION: The method comprises the steps of pulverizing the waste polystyrene at an injection molding apparatus(1) and injecting the pulverized one into a melting bath(2); melting the waste polystyrene at a temperature of 200-300 deg.C for 30 min to 5 hours to remove insoluble materials and to control a molecular weight; injecting the molten waste polystyrene into a reactor(3) by using a screw, and thermal-decomposing it at a temperature of 200-1,000 deg.C for 1-2 hours; and liquefying the thermally decomposed gas through a heat exchanger(4) to obtain an oil, and collecting the oil at an oil collect bath(5). Preferably the waste polystyrene injected to the reactor has a molecular weight of 90,000-200,000.