Development of Highly Efficient Solar Thermal Desalination Technology Using Eco-friendly Wood Scrolls

Abstract

A wood scroll evaporator is developed by rolling a wood layer. Two types of evaporators with parallel natural water channels (p-WS) or diagonal natural water channels (d-WS) are fabricated. When a wood layer is rolled into a scroll, gap channels, which improve the water transport in the vertical direction, are fabricated between the overlapping wood layers. Because diagonal natural water channels enhanced lateral water transport compared to microchannels, the water transport between the wood layers is facilitated. The synergistic effect of gap channels and diagonal channels in d-WS enables high water evaporation performance and salt resistance. The total water evaporation rate of d-WS is 9.08 kg m-2h-1 under 1 sun illumination and increases to 24.42 kg m−2 h−1 under 1 m s−1 wind which are among the highest evaporation rate ever reported. Salt resistance and the evaporation rate of d-WS are maintained even after 5 d, which indicates that d-WS can be used in long-term operation.