TY - JOUR
T1 - Upscaling 3D Engineered Trees for Off-Grid Desalination
AU - Zheng, Sunxiang
AU - Yang, Meiqi
AU - Chen, Xi
AU - White, Claire E.
AU - Hu, Liangbing
AU - Ren, Zhiyong Jason
N1 - Funding Information:
The authors thank the Andlinger Center for Energy and the Environment at Princeton University and Princeton Catalysis Initiative (PCI) for financial support. We acknowledge the use of Princeton’s Imaging and Analysis Center, which is partially supported through the Princeton Center for Complex Materials (PCCM), a National Science Foundation (NSF) - Materials Research Science and Engineering Center (MRSEC) program (DMR-1420541 and DMR-2011750).
Publisher Copyright:
© 2022 American Chemical Society
PY - 2022/1/18
Y1 - 2022/1/18
N2 - More than 70% of the population without access to safe drinking water lives in remote and off-grid areas. Inspired by natural plant transpiration, we designed and tested in this study an array of scalable three-dimensional (3D) engineered trees made of natural wood for continuous water desalination to provide affordable and clean drinking water. The trees took advantage of capillary action in the wood xylems and lifted water more than 1 foot off the ground with or without solar irradiation. This process overcame some major challenges of popular solar-driven water evaporation and water harvesting, such as intermittent operation, low water production rate, and system scaling. The trade-off between energy transfer and system footprint was tackled by optimizing the interspacing between the trees. The scaled system has a ratio of surface area (vapor generation) to project area (water transport) up to 118, significantly higher than the prevailing flat-sheet design. The extensive surface area evaporated water at a temperature cooler than the surrounding air, drawing on multiple environmental energy sources including solar, wind, or ambient heat in the air and realized continuous operation. The total energy for evaporation reached over 300% of the one-sun irradiance, enabling a freshwater production rate of 4.8 L m–2 h–1 from an array of 16 trees in an enclosed room and 14 L m–2 h–1 under a 3 m/s airflow. Furthermore, we found that the ambient heat in the air contributed 60%–70% of the total latent heat of vaporization when energy sources were decoupled. During long-term desalination tests, the engineered trees demonstrated a self-cleaning mechanism with daily cycles of salt accumulation and dissolution. Combining the quantification from an evaporation model and meteorology data covering the globe, we also demonstrated that the 3D engineered trees can be of particular interest for sustainable desalination in the Middle East and North Africa (MENA) regions.
AB - More than 70% of the population without access to safe drinking water lives in remote and off-grid areas. Inspired by natural plant transpiration, we designed and tested in this study an array of scalable three-dimensional (3D) engineered trees made of natural wood for continuous water desalination to provide affordable and clean drinking water. The trees took advantage of capillary action in the wood xylems and lifted water more than 1 foot off the ground with or without solar irradiation. This process overcame some major challenges of popular solar-driven water evaporation and water harvesting, such as intermittent operation, low water production rate, and system scaling. The trade-off between energy transfer and system footprint was tackled by optimizing the interspacing between the trees. The scaled system has a ratio of surface area (vapor generation) to project area (water transport) up to 118, significantly higher than the prevailing flat-sheet design. The extensive surface area evaporated water at a temperature cooler than the surrounding air, drawing on multiple environmental energy sources including solar, wind, or ambient heat in the air and realized continuous operation. The total energy for evaporation reached over 300% of the one-sun irradiance, enabling a freshwater production rate of 4.8 L m–2 h–1 from an array of 16 trees in an enclosed room and 14 L m–2 h–1 under a 3 m/s airflow. Furthermore, we found that the ambient heat in the air contributed 60%–70% of the total latent heat of vaporization when energy sources were decoupled. During long-term desalination tests, the engineered trees demonstrated a self-cleaning mechanism with daily cycles of salt accumulation and dissolution. Combining the quantification from an evaporation model and meteorology data covering the globe, we also demonstrated that the 3D engineered trees can be of particular interest for sustainable desalination in the Middle East and North Africa (MENA) regions.
KW - Desalination
KW - Engineered Tree
KW - Environmental Energy
KW - Solar Evaporation
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U2 - 10.1021/acs.est.1c05777
DO - 10.1021/acs.est.1c05777
M3 - Article
C2 - 34982541
AN - SCOPUS:85122780488
SN - 0013-936X
VL - 56
SP - 1289
EP - 1299
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 2
ER -