Exploring potential of paraffin wax: A phase change material for improving yield of solar still

The necessity of providing fresh water to the existing population has remained a significant challenge, highlighting the utmost necessity of a sustainable water purification technique. Therefore, the present review article investigates the recent developments in paraffin wax-based enhancements for solar stills for improving freshwater yield. Paraffin wax, a widely used phase change material (PCM), offers high latent heat storage and chemical stability; however, its low thermal conductivity and long-term reliability present significant challenges. Therefore, this article aims to provide sufficient knowledge on the most practical designs of solar still with paraffin wax. Also, the review highlights design modifications, placement strategies, nanoparticle incorporation, and external attachments like heat exchangers and collectors that have been employed to enhance distillate yield. Economic analyses indicate that paraffin-enhanced systems offer lower water production costs compared to conventional solar stills. Challenges such as phase segregation, volumetric expansion, and material degradation over repeated cycles are discussed. This review aims to provide a comprehensive understanding of optimizing solar still performance using paraffin wax, supporting future research and practical implementation for sustainable water desalination. The key findings indicate that pyramid-shaped solar stills are the most suitable design and their integration with paraffin wax can significantly improve the distillate yield by 100 %.