Processing Technology for Municipal Waste Containing Plastics

Abstract

At present in Tokyo metropolitan district incombustibles and waste unfit for incineration is dumped at the landfill site. The landfill is however unfavorable method to dispose such waste considering the limitted capacity of landfill site. Because such waste (combustibles and waste unfit for incineration), 20-25 percent of which is occupied by plastics has large volume, in fact its density is only 0.1 t/m³ or so. Adding that plastics is difficult materials to resolve in the soil. For this reason, technical study for processing incombustibles and waste unfit for incimeration has been made. Applied system is based on pyrolysis gas combustion method in which rotary kiln and after burnig stoker are combined. Processing principle is as follows: that part of exhaust gas in circulated to rotary kiln to pyrolize waste containing plastics, gas generated by pyrolysis secondarily burns at after burning and residue most of which is pure carbon is completely incinerated on after combustion grate. Through substantial tests, it is certified that incombustibles and waste for incineration containing plastics are able to be processed by this method without technical and environmental problems, and it is also proved that no obstacle exists to put it to practical use at full-scale plant.