Scientists at a university in Scotland believe they have discovered a way to turn waste water from the whisky industry into sustainable fuel.
A team from Heriot-Watt University has developed materials that can use waste water from distilleries to produce green hydrogen which, unlike fossil fuels, does not produce carbon when it is burned.
Green hydrogen is normally created using fresh water in a process thought to consume around 20.5 billion litres of fresh water every year.
The Heriot-Watt team hope the material it has developed will see some of the estimated one billion litres of waste water produced by the distilling industry each year used to create green hydrogen instead.
Dr Sudhagar Pitchaimuthu, a materials scientist at the university’s School of Engineering and Physical Sciences, explained: “It takes nine kilogrammes of water to produce every one kilogramme of green hydrogen. Meanwhile, every one litre of malt whisky production creates about 10 litres of residue.
“To help protect the planet, we need to reduce our use of fresh water and other natural resources. So our research focused on how to use this distillery waste water for green hydrogen production with a simple process that removes waste materials present in the water.”
Dr Pitchaimuthu and his team have developed a nanoscale material – a particle 1/10,000 the diameter of a human hair – to allow distillery waste water to replace fresh water in the green hydrogen production process.
The nanoparticle, called a nickel selenide, treats the waste water and produces similar or slightly higher quantities of green hydrogen during research compared to fresh water.
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The research is published in the Royal Society of Chemistry journal, Sustainable Energy & Fuels, in a paper authored by Dr Pitchaimuthu’s PhD student, Michael Walsh, who played a key role in conducting the study.
“About one billion litres of waste water a year is produced from the distilling industry, so the potential of this process is huge,” Dr Pitchaimuthu continued.
“Using industry waste water means we can reduce the extensive fresh water footprint associated with green hydrogen production. Our research also shows how we can use the world’s resources more sustainably to produce clean energy.”
The next steps for the Heriot-Watt research team include developing their own electrolyser prototype and scaling up production of their nickel selenide nanoparticles.
They will also analyse distillery waste water to discover whether other materials of value could be salvaged from it, alongside hydrogen and oxygen.
The research was funded by Heriot-Watt’s School of Engineering and Physical Sciences and completed in collaboration with the University of Bath’s Department of Chemical Engineering and The Scotch Whisky Research Institute.