Augmenting the potable water produced from single slope solar still using CNT-doped paraffin wax as energy storage: an experimental approach

Abstract

The present study aims to find the technical feasibility of recently evolved nanomaterial, i.e. carbon nanotubes (CNT), enhanced with paraffin as a novel energy storage material for desalination application. As a primary investigation, the thermo-mechanical properties like density, melting point, thermal conductivity, etc., of CNT enhanced paraffin were first analysed and then integrated with solar desalination application. Three solar desalination stills: (i) conventional solar still, (ii) solar still loaded with fossil paraffin and (iii) solar still loaded with CNT-doped paraffin were fabricated and experimented at Chennai, India (Lat. 13° 08′ N, Long. 80° 27′ E). From the investigation, it is inferred that there is a significant increase (of about 26%) observed in the thermal conductivity of CNT-doped paraffin as compared to fossil paraffin. The cumulative yield of the conventional still, solar still with paraffin and solar still with CNT enhanced paraffin was found to be 2.5 kg/m2, 3.4 kg/m2 and 5.8 kg/m2, respectively. There was 41.4% and 26.4% enhancement, respectively, observed in the daily yield of the solar still with CNT-doped paraffin as compared to conventional still and the still with virgin paraffin. The productivity efficiency was 46.45% for the still with CNT blended paraffin contributing to 24% and 19.6% increase in the efficiency as compared to the other two stills considered for experimentation in this study. Thus, it is concluded that CNT enhanced paraffin is identified as a better potential energy storage material as compared to conventional paraffin in solar desalination application.