Work

Improved water-evaporation efficiency with helium sparging in a hot-bubble pilot plant

Year: 2025

Type: article

Abstract: Helium sparging can greatly improve the evaporation efficiency, compared with air sparging, in sub-boiling desalination processes, even at relatively low operating temperatures, in the range 40–80°C. This effect apparently occurs because heated helium gas can more easily penetrate across the gas/water interface and weaken the hydrogen bonding in water clusters near the interface, thereby increasing the local evaporation efficiency. This mechanism is supported by density-functional theory/molecular-dynamics calculations. To evaluate the higher evaporation efficiency and lower energy demand, the energy used for water evaporation from a 0.5 m NaCl solution with different helium-air mixtures at inlet-gas temperatures of 90°C, 120°C and 147°C was measured using a hot-bubble pilot plant (HBPP). The HBPP showed an enhanced efficiency using helium than with just air, leading to a reduced energy consumption. These results suggest that the use of helium, with recycling, in a large-scale HBPP could greatly improve evaporation efficiency and provide an energy-efficient method for seawater desalination.

Source: Chemical Engineering Science

DOI: 10.1016/j.ces.2025.122564

Authors: Thi Thuy Nguyen, Rui Wei, Adrian Garrido Sanchis, Terry Frankcombe, Peter McIntyre, Richard M. Pashley

Institution: UNSW Canberra

Language: English

Topic: Solar-Powered Water Purification Methods

Subfield: Renewable Energy, Sustainability and the Environment

Field: Energy

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: hybrid

Estimated APC paid: $4,050