Enhancing desalination performance of a stepped solar still using nano-enhanced phase change material and condenser integration

Abstract

This research investigates methods to improve the desalination performance of stepped solar stills, a design known for its high productivity but limited commercial viability. The study proposes modifications using nano-enhanced phase change material (NPCM) and a condenser to enhance water production. Two configurations were built and tested under identical weather conditions: a conventional stepped solar still (CSSS) and a modified stepped solar still (MSSS). Results indicated a significant increase in both productivity and efficiency for MSSS over CSSS. MSSS achieved a desalination yield of 4800 mL/m2.day, a 60 % improvement over the 3000 mL/m2.day yield of the CSSS. Further advancements were observed with the integration of NPCM. The MSSS with NPCM reached a yield of 5150 mL/m2.day, while the CSSS with NPCM remained lower at 2700 mL/m2.day (90 % improvement). The most notable enhancement (110 %) was achieved by combining the MSSS with NPCM and a condenser. This configuration yielded 5950 mL/m2.day, compared to 2850 mL/m2.day for the CSSS with NPCM and condenser. This study demonstrates the effectiveness of NPCM and condenser integration in significantly boosting the desalination performance of stepped solar stills, potentially paving the way for their wider commercial adoption. Furthermore, the annual CO₂ emissions for both MSSS + NPCM and MSSS + NPCM + condenser is approximated to be 31.9 & 30.8 tons/year, severally. Additionally, the enviroeconomic arguments are valued at 462.5 & 446.6 a year for MSSS + NPCM and MSSS + NPCM + condenser forms, individually.