Extendable Solar Interfacial Evaporator with High Salt Resistance Achieved by Managing the Evaporation Region

Abstract

Zero‐liquid‐discharge‐type solar interface evaporators have shown great potential for applications in areas such as desalination and salt production. Edge‐crystallization‐type evaporators using a single water supply column composition are widely investigated. However, the evaporator area is limited by the water supply capacity of a single water supply column, making it difficult to scale‐up. Herein, an evaporative area management (EAM) strategy is proposed to enable the evaporator to build a larger area by applying multiple water supply columns while avoiding crystallization on the evaporating surface. The salt‐tolerance performance and mechanism of the EAM strategy are investigated through experiments and simulations, and the optimal evaporation performance is achieved through parameter optimization. The seven‐stage multistage distillation device assembled with the optimized EAM strategy achieves a fourfold increase in evaporation area at 1 kW m−2 light intensity and 3.5 wt% NaCl solution with a stable evaporation rate of 1.8 kg m−2 h−1 and a salt yield of 66 × g m−2 h−1. In particular, the device maintains stable evaporation under 2 kW m−2 concentrated light conditions and 7 days of cyclic operation. Thus, this stable operation salt‐tolerance strategy provides a promising option for scale‐up desalination technology.