Photovoltaic-multistage desalination of hypersaline waters for simultaneous electricity, water and salt harvesting via automatic rinsing

• DOI: 10.1016/j.nanoen.2021.106163
• Publication Date: 2021-05-19T16:39:11Z
• Authors: Liping Yang; Tianyu Sun; Jiebin Tang; Yang Shao; Ningbo Li; Anqi Shen; Jialin Chen; Yafang Zhang; Hong Liu; Guobin Xue
• Keywords: 13. Climate action; 7. Clean energy; 01 natural sciences; 6. Clean water; 0104 chemical sciences

Abstract Passive solar multistage stiller with heat localization has shown great potential in wastewater purification and seawater desalination due to its ultrahigh solar-to-vapor conversion ability. However, achieving high water yield with long stability remains a great challenge because of the salt clog. Here, we demonstrated a photovoltaic-multistage stiller (PV-MS) with excellent salt-rejecting ability, even when dealing with hypersaline waters. The solar energy is converted to electricity and heat by a commercial photovoltaic panel and the waste heat subsequently drives the passive multistage stiller. The capillary wick and the crystalized salt at the edge of the wick form a siphon channel and the crystalized salt was rinsed intermittently by the siphon action, thereby avoiding salt clog. Thus, we achieved simultaneous electricity, water and salt collection in the integrated photovoltaic-thermal utilization system with long-term stability. Under one sun, the water yield of a five-stage stiller was about 1.17 kg m−2 h−1 with electricity output of 97 W m−2 and salt collection of 1.02 kg m−2 d−1 when desalinating hypersaline NaCl solution of 170 g/L. We envision that such a technology can help full use of solar energy in desalinating high-salinity waters with long term stability and is greatly promising at the water-energy nexus.