Transient transport phenomena in lithium-rich solar evaporation ponds: A case study in the Atacama Salt Flat, Chile

Abstract

Lithium extraction from brines plays a key role in the global transition toward sustainable energy systems, yet the transient thermophysical behavior of lithium-rich solar evaporation ponds (LiSEPs) under real environmental conditions remains unexplored. This study presents a computational framework developed in OpenFOAM to analyze the transient transport of mass, energy, and momentum in a LiSEP located in the Atacama Salt Flat, Chile. The model incorporates variable boundary conditions to evaluate mass and energy exchanges with the environment, accounting for evaporative cooling and radiative heat transfer. The results reveal diurnal patterns with shifts in exchange direction between the environment and the LiSEP. Over eight days, cumulative water evaporation reached 143.24 kg/m², with salinity increasing from 25% to 29.04%. Cloudy days reduced solar radiation by 54.56%, halving evaporation rates and salinity growth compared to sunny days. Seasonal analysis showed that summer evaporation rates were 2.30 times higher than winter rates due to increased solar radiation. These findings highlight the importance of accounting for environmental variability in optimizing the development of LiSEPs under diverse climatic conditions.