CONVERSION OF PLASTIC MATERIAL INTO OIL

摘要

PROBLEM TO BE SOLVED: To enable efficient conversion of even mixed plastics containing polyolefin and polystyrene into an oil by supplying water to a reaction system for the thermal decomposition of the plastic materials to obtain an oil. SOLUTION: An oily material is obtained by the thermal decomposition of plastic materials while supplying water to a reaction system in the presence of a synthetic silica-alumina solid acid catalyst having a crystallinity of <=5% determined from the intensity of a diffraction line spectrum obtained by powder X-ray diffraction analysis expressed by the formula crystallinity = [S1 /(S1 +S2 )]×100(%)} (S1 is the area of a diffraction line spectrum having a diffraction angle (2θ) range of 22-42 deg.; S2 is the area of a diffraction line spectrum having a diffraction angle (2θ) range of 20-70 deg.), a silica/alumina weight ratio (SiO2 /Al2 O3 ) of 90/10 to 65/35 and an acid value of <=0.4mgKOH/g.