Study of the relative humidity effects on the water condensation performance of adsorption-based atmospheric water harvesting using passive radiative condensers

S. Bai; L. C. Chao; A. Pan; T. C. Ho; K. Lin; C. Y. Tso

doi:10.1016/j.applthermaleng.2024.122702

Study of the relative humidity effects on the water condensation performance of adsorption-based atmospheric water harvesting using passive radiative condensers

S. Bai, L. C. Chao, A. Pan, T. C. Ho, K. Lin, C. Y. Tso^*

^*Corresponding author for this work

School of Energy and Environment

Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review

13 Citations (Scopus)

6 Downloads (CityUHK Scholars)

Abstract

Adsorption-based atmospheric water harvesting (ABAWH) and passive radiative condensers are two examples of dew water collection. The application of passive radiative condensers to ABAWH has recently been demonstrated. However, ABAWH prefers high relative humidity (RH) for higher water uptake by adsorbents, while radiative condensers favor low RH for higher radiative cooling power, so there exists a desired RH for the water harvesting system under different conditions. However, this has not been previously studied. Therefore, we pioneer the development of a numerical model to obtain the desired RH for the water harvesting system and determine optimum operating parameters for maximum water production under different conditions. The adsorption isotherms are fit based on experimental results, and the effect of RH on radiative cooling power is mathematically predicted via cloud-cover fraction. Based on the numerical results, the desired RH ranges from 20 % to 29 % for 200 g MIL-101-Cr (HF) under certain conditions. Compared to other factors, the radiative condensation emitter and climate have a greater influence on the water condensation rate. Overall, this work provides guidelines on the design and setting of in-situ large-scale applications of ABAWH systems using passive radiative condensers for the greatest decentralized freshwater condensation performance under specific weather conditions. © 2024 Elsevier Ltd

Original language	English
Article number	122702
Number of pages	14
Journal	Applied Thermal Engineering
Volume	244
Online published	12 Feb 2024
DOIs	https://doi.org/10.1016/j.applthermaleng.2024.122702
Publication status	Published - 1 May 2024

Funding

This study is supported by the Hong Kong Research Grant Council via General Research Fund (GRF) account 11200022 , as well as Innovation and Technology Commission via Innovation and Technology Fund (ITF) account ITS/128/22FP .

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 6 Clean Water and Sanitation

Research Keywords

Adsorption
Atmospheric Water Harvesting
Passive Radiative Condensers
Radiative Condensation Emitters
Relative Humidity

Publisher's Copyright Statement

COPYRIGHT TERMS OF DEPOSITED POSTPRINT FILE: © 2024 Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/

RGC Funding Information

RGC-funded

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title = "Study of the relative humidity effects on the water condensation performance of adsorption-based atmospheric water harvesting using passive radiative condensers",

abstract = "Adsorption-based atmospheric water harvesting (ABAWH) and passive radiative condensers are two examples of dew water collection. The application of passive radiative condensers to ABAWH has recently been demonstrated. However, ABAWH prefers high relative humidity (RH) for higher water uptake by adsorbents, while radiative condensers favor low RH for higher radiative cooling power, so there exists a desired RH for the water harvesting system under different conditions. However, this has not been previously studied. Therefore, we pioneer the development of a numerical model to obtain the desired RH for the water harvesting system and determine optimum operating parameters for maximum water production under different conditions. The adsorption isotherms are fit based on experimental results, and the effect of RH on radiative cooling power is mathematically predicted via cloud-cover fraction. Based on the numerical results, the desired RH ranges from 20 % to 29 % for 200 g MIL-101-Cr (HF) under certain conditions. Compared to other factors, the radiative condensation emitter and climate have a greater influence on the water condensation rate. Overall, this work provides guidelines on the design and setting of in-situ large-scale applications of ABAWH systems using passive radiative condensers for the greatest decentralized freshwater condensation performance under specific weather conditions. {\textcopyright} 2024 Elsevier Ltd",

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Study of the relative humidity effects on the water condensation performance of adsorption-based atmospheric water harvesting using passive radiative condensers. / Bai, S.; Chao, L. C.; Pan, A. et al.
In: Applied Thermal Engineering, Vol. 244, 122702, 01.05.2024.

Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review

TY - JOUR

T1 - Study of the relative humidity effects on the water condensation performance of adsorption-based atmospheric water harvesting using passive radiative condensers

AU - Bai, S.

AU - Chao, L. C.

AU - Pan, A.

AU - Ho, T. C.

AU - Lin, K.

AU - Tso, C. Y.

PY - 2024/5/1

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AB - Adsorption-based atmospheric water harvesting (ABAWH) and passive radiative condensers are two examples of dew water collection. The application of passive radiative condensers to ABAWH has recently been demonstrated. However, ABAWH prefers high relative humidity (RH) for higher water uptake by adsorbents, while radiative condensers favor low RH for higher radiative cooling power, so there exists a desired RH for the water harvesting system under different conditions. However, this has not been previously studied. Therefore, we pioneer the development of a numerical model to obtain the desired RH for the water harvesting system and determine optimum operating parameters for maximum water production under different conditions. The adsorption isotherms are fit based on experimental results, and the effect of RH on radiative cooling power is mathematically predicted via cloud-cover fraction. Based on the numerical results, the desired RH ranges from 20 % to 29 % for 200 g MIL-101-Cr (HF) under certain conditions. Compared to other factors, the radiative condensation emitter and climate have a greater influence on the water condensation rate. Overall, this work provides guidelines on the design and setting of in-situ large-scale applications of ABAWH systems using passive radiative condensers for the greatest decentralized freshwater condensation performance under specific weather conditions. © 2024 Elsevier Ltd

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Study of the relative humidity effects on the water condensation performance of adsorption-based atmospheric water harvesting using passive radiative condensers

Abstract

Funding

UN SDGs

Research Keywords

Publisher's Copyright Statement

RGC Funding Information

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ITF: Study and Development of Novel and Next-Generation Self-Cooling Building Materials using Daytime Passive Radiative Cooling Technology

GRF: Chameleon-inspired Self-adaptive Daytime Passive Radiative Coolers with Cooling Power Modulation Ability for Building Applications

Cite this

Study of the relative humidity effects on the water condensation performance of adsorption-based atmospheric water harvesting using passive radiative condensers

Abstract

Funding

UN SDGs

Research Keywords

Publisher's Copyright Statement

RGC Funding Information

Access Output

Other Access Options

Permanent Link

Other Files and Links

Fingerprint

Projects

ITF: Study and Development of Novel and Next-Generation Self-Cooling Building Materials using Daytime Passive Radiative Cooling Technology

GRF: Chameleon-inspired Self-adaptive Daytime Passive Radiative Coolers with Cooling Power Modulation Ability for Building Applications

Cite this