Waste tyre pieces as photothermal absorbers for efficient evaporation in solar desalination systems

Valorizing and reusing waste materials before recycling can yield sustainable outcomes and reduce environmental effects. Among various waste materials, automobile tyres are significant contributors to environmental pollution when burned due to their rubber content. Therefore, worn/waste tyres from cars, with an average thickness of about 5–6 mm, are procured and made into small pieces (2 inches × 2 inches) for investigation of their photothermal absorption in solar thermal applications. Among the available solar thermal applications, solar stills offer a cheap and uncomplicated desalination approach that can be accessible to everyone. However, conventional solar stills have low clean water production rates. Thus, the primary objective of this study is to enhance pure drinking water generation by introducing black tyre pieces into the absorber basin of solar still, which exhibits greater heat absorption. The findings of the study reveal that the clean water production in the solar still with tyre pieces (SS-Tyre) is improved by an additional 18% compared to conventional solar stills (CSS). The clean water production from SS-Tyre measures approximately 2.7 L per square metre, while the distillate output of CSS amounts to about 2.3 L per square metre over two consecutive testing days. Moreover, the cost assessment demonstrates that the cost per litre (CPL) and payback time (PT) of SS-Tyre are 19.2% and 20.1% lower, respectively, than CSS. Furthermore, the environmental impact assessment indicates that SS-Tyre yields 19% more net carbon credit than CSS. By effectively repurposing waste automobile tyres and incorporating them into solar stills, this study not only improves clean water production but also reduces costs and environmental impact.