By Lauren DeLorenzo, Journalist, Energy magazine
As we transition to more sustainable energy sources, it’s clear that hydrogen production will play a major role in powering the future, with the Federal Government aiming to position Australia’s hydrogen industry as a major global player by 2030. Monash University researchers, together with national water utilities, are now looking at ways to produce hydrogen energy more sustainably through repurposing wastewater, putting Australia one step closer to its hydrogen targets.
Hydrogen is a clean energy source that can be used in a number of ways, either as fuel for transport or heating, a way to store electricity, or as a raw material in industrial processes.
However, the production of hydrogen requires abundant renewable energy and a consistent water supply to produce scalable and sustainable energy for commercial use.
As a result, at least 5.5 billion litres of water is needed annually to achieve the hydrogen production target proposed in Australia’s National Hydrogen Strategy for the estimated 2030 export market, which is equivalent to the annual water consumption of 1.6 million people.
Monash University’s Sustainable Hydrogen Production from Used Water project aims to address the challenge of water scarcity in the process of hydrogen production.
The project aims to develop an innovative approach that repurposes wastewater as the feed for hydrogen production through water electrolysis – the process of using electricity to split water into hydrogen and oxygen.
The three-year research project began when Water Research Australia started to explore the role of water utilities in the hydrogen industry, but soon more partners joined the project.
The project received an ARC Linkage grant, which was funded by the Australian Research Council and aims to encourage the joint effort of Monash, WaterRA, and GrapheneX to provide innovative solutions.
The group of researchers, Professor Xiwang Zhang, Professor Huanting Wang, and Dr Yinlong Zhu, from the Department of Chemical Engineering at Monash University, will look to advance the practical applications of water electrolysis for scalable and sustainable hydrogen production, and help Australia secure a leading position in the global emerging hydrogen economy.
Chemical Engineering Professor and Director of the ARC Research Hub for Energy-efficient Separation, Xiwang Zhang, explained the process of water electrolysis for hydrogen production.
“PEM electrolysers adopt polymer-electrolyte membranes as solid electrolytes, transporting proteins and separating gaseous reaction products,” Professor Zhang said.
“Cathode and anode electrocatalysts are deposited on the two sides of the membranes, for the two half-reactions of water electrolysis, hydrogen evolution reaction (HER), and oxygen evolution reaction (OER), respectively.”
With the broader goal of advancing applications of wastewater in hydrogen production, the research will focus on three targeted objectives.
Professor Zhang explained that the first objective was to gain an in-depth understanding of how electrocatalysts and membranes perform in the presence of different concentrations of key impurities, and develop guidelines for designing water electrolysers with a high tolerance of water impurities.
The second objective aimed to identify the water quality gap between the treated water from existing wastewater treatment plants (WWTPs) and the required feed water for water electrolysis, and provide recommendations for WWTPs operation and potential upgrading.
Finally, Professor Zhang said they would also evaluate the feasibility of utilising the co-products from water electrolysis in wastewater treatment, and develop frameworks for the integration between wastewater treatment and water electrolysis.
Professor Zhang said this project presents an opportunity to minimise freshwater consumption and use the large amounts of wastewater generated in Australia’s major capital cities.
“The amount of wastewater currently available for use is far more than the amount of water required in water electrolysis for hydrogen production,” Professor Zhang said.
“Most of the treated water throughout Australia is currently discharged to surrounding water bodies or recycled for irrigation after being treated in centralised municipal wastewater treatment plants. “Given the volume of the treated water from these plants is highly consistent, it is a promising water source for water electrolysis.”
Australian Laureate Fellow and Director of Monash Centre for Membrane Innovation, Professor Wang, said, “With our expertise in water electrolysis, membranes, and water treatment, we are pleased to have this opportunity to work with our industry partners to contribute to the development of renewable hydrogen technology using recycled water.”
The project will work closely with water utilities South East Water, Melbourne Water, Yarra Valley Water and Water Corporation, through Water Research Australia (WaterRA).
WaterRA Research Manager, Dr Arash Zamyadi, is the Partner Investigator, and said although the majority of pollutants in wastewater have been effectively removed in the current wastewater treatment processes, small amounts of impurities (residual organics and ions) remain.
“There still remains a knowledge gap in how the impurities affect water electrolyser design and process operation,” Dr Zamyadi said.
“Through this research, we hope to develop an in-depth understanding of the impacts of water impurities in used water on the performance and durability of water electrolysers, and subsequently develop guidelines for the design of highly durable water electrolysers and the operation and upgrade of existing wastewater treatment plants.”
The findings from this project have the capability to contribute to the global hydrogen export market, with demand for hydrogen exported from Australia alone tipped to be over three million tonnes each year by 2040. If found to be feasible, researchers estimate that wastewater could be used in commercial-scale hydrogen production in the next three to five years.