The Application of a Solar Parabolic Trough Collector for the Melting of Plastic Waste

Abstract

Municipal waste, comprised partially of plastic, has negative ecological impacts on a global scale. Developing countries face unique challenges in collecting and recycling their waste, where even in developed countries, recycling rates of plastics rarely approach 100%. Reshaping plastics into usable products requires a considerable amount of heat energy and infrastructure, which particularly impacts the accessibility of recycling technologies to developing countries. In regions with sufficient sunlight, solar cookers designed for the 150–200 °C range most useful for food preparation may be able to reach temperatures hot enough to also melt plastics, where the melting point of most common plastics is below 200 °C. The aim of this study was to test the feasibility of applying a parabolic trough collector for melting plastic waste. The lack of published data on this particular application of solar thermal collectors highlights a significant research gap. Two different prototypes were tested after improvements in the sheet metal material and parabolic shape were realized. Results demonstrated that a non-evacuated tube solar cooker constructed with simple methods and locally available materials could reach temperatures as high as 139 °C within one hour of testing in Stockholm, Sweden. ABS plastic waste from a 3D printer was successfully melted in this process. The final prototype was tested in Ioannina, Greece in collaboration with the refugee-aiding FabLab, Habibi.Works. Temperatures inside the collector were measured at a maximum value of 211 °C in Greece. The results were examined in the context of developing areas and refugee camps and suggest that this may be feasible and affordable for developing countries. Further research should be conducted on the potential of solar cooker designs to be applied for waste reduction in these areas of the world.