Improving thermal efficiency of solar stills: Bioactive nano-PCM and Cramer’s rule analysis

Abstract

Green-sourced Petroselinum crispum leaf (P) was carefully harvested and underwent extraction processes. This material was then combined with TiO2 nanoparticles (T) into paraffin wax (P) to create the PTP nanocomposite, using an economically viable and environmentally friendly approach, with P serving as a consistent, reducing, and stabilizing element. The synthesized PTP was thoroughly analyzed using Spectrophotometer, Fourier-transform-IR spectroscopy, X-Ray diffraction, DSC, TGA, and SEM for characterization. The PTP samples were applied in constructing a Single Slope Wick Solar Still (SWS), aiming to induce surface plasmon resonance around 450 nm across the absorber plate. The excitation of PTP at SPR led to the release of significant heat, contributing to temperature increments of the aqueous medium by varying percentages (10 %, 20 %, 30 %, and 40 %) under different ratios upon exposure to solar radiation at the precise plasmon resonance wavelength. This study introduced the first-time application of Cramer's rule (determinant technique) in solving energy balance equations for temperature components. Evaluation revealed that incorporating 30 % PTP notably enhanced SWS efficiency, achieving an optimal distillate output of 8.70 l/m2day, including 1.95 l/m2 at night, resulting in an efficiency of 42.74 %.