Grant for work on thermal desal, irrigation

RMIT University research into an alternative water desalination and an irrigation system driven by thermal energy has received a boost in the form of a $132,000 grant from the Australian-India Strategic Research Fund.

Jacqueline Ong

Dr Abhijit Date, lecturer RMIT's School of Aerospace, Mechanical and Manufacturing Engineering was awarded the grant for his research into a sustainable and economical fresh water management system that could be used in coastal areas of India and salt-affected farming land in Australia.

The system uses a special thermal water pump developed at RMIT University and the University of Pune, India, which is driven by low-temperature thermal energy rather than electricity.

"There are many poor coastal communities in India where access to fresh water is an issue but they cannot afford to use standard power-hungry desalination and irrigation systems," Date explained.

"The desal and irrigation system we are developing is both cheap to run and sustainable, producing no greenhouse gas emissions."

"Not only could this system help many coastal communities, it could also enable saline groundwater to be turned into fresh water and used for agricultural irrigation – helping farmers in Australia and across the world," Date said.

RMIT said the system runs on clean power sources, such as solar thermal, geothermal or waste heat, and generates both fresh water and water pumping power using thermal energy at temperatures below 100C.

Researchers have built a lab-scale prototype of the thermal water pump system, with early tests showing the system can produce 1000 litres of fresh water from 2000 litres of saline feed water with a salt concentration between 5000-15,000 grams per cubic metres.

The system works by boiling a refrigerant at constant temperature and using the pressurised refrigerant vapour to power a piston and pump water out. To suck water in, the vapour is cooled down, reducing the volume, pushing the piston in the opposite direction.

“The success of this project will provide a much needed alternative system that can be manufactured in Australia and provide opportunity for industry development, employment creation and export,” Date said.