Gasification of waste tyre and plastic (PET) by solar thermochemical process for solar energy utilization

Waste tyre and plastic such as polyethylene terephthalate can be utilized as a useful material for conversion of solar energy into chemical energy by solar thermochemical gasification into synthesis gas (CO + H-2) using concentrated solar energy. In the present paper, the gasification of waste tyre (C: 86 wt.%, H: 8.4 wt.%) and of PET (C10H8O4)(n), were studied using ZnO as a donor of oxygen in the infra-red furnace at 1373 K. For the gasification of tyre, most of the chemically bound hydrogen was converted into H, (62%) and CH4 (29%) gases, while 71 mole% of the inherent carbon was gasified to CO (36%), CH4 (29%), C2H4 (2%), and CO2 (4%) in 200 s of the decomposition reaction. The CO2:CO ratio was about 1/10, indicating that the carbon in the waste tyre can be converted effectively to gaseous fuels. In the experiment without ZnO, the conversion efficiency of C and H were decreased to 17% and 77%, respectively. However an appreciable effect of ZnO on the enhancement of the gasification of PET was not observed. (C) 1998 Elsevier Science Ltd. All rights reserved.