METHOD AND APPARATUS FOR RECOVERING OIL FROM WASTE PLASTIC

摘要

A method for recovering oil from waste plastic that causes no trouble even when thermosetting resin or solid foreign matters are mixed, whereby the burden of a pre-processing separating process for urban refuse or industrial wastes is remarkably reduced, comprising, when oil is recovered by heat decomposing waste plastic including vinyl chloride or other types of chlorine, the steps of mixing waste plastic with high temperature sand and or an additive before a thermal decomposition process while extruding and causing the waste plastic to flow and heating it to a temperature of 250 to 350 DEG C to thereby produce a processed material comprising the waste plastic from which chlorine is actually removed and the sand, mixing the processed material with high temperature sand to thereby directly heat the mixture to a temperature of 350 to 500 DEG C and hold it at that temperature so that the waste plastic is heated and thermally decomposed, dividing the thermally decomposed product obtained by the thermal decomposition process into a liquid oil having a high boiling point, a gas oil having a low boiling point and a low molecular gas by means of a first gas-liquid separating means so as to obtain a high-quality oil at a low boiling point, and connecting a process for refluxing the high boiling point oil to the thermal decomposition process and a process for dividing it into a liquid oil having a low boiling point and a low molecular gas by means of a second gas-liquid separating means in series.