Wastewater from the distilling industry could be used to produce green hydrogen fuels thanks to materials developed by scientists at Heriot-Watt University, Scotland.
Around 1 million litres of wastewater from the whisky distilling process is produced every year in Scotland (globally the figure is thought to be closer to 1 billion litres).
Researchers at Heriot-Watt have however developed a way to use this wastewater to produce green hydrogen. “It takes 9kg of water to produce every 1kg of green hydrogen. Meanwhile, every 1 litre of malt whisky production creates about 10 litres of residue,” explained Sudhagar Pitchaimuthu, a materials scientist in the university’s school of engineering and physical sciences. “So our research focused on how to use this distillery wastewater for green hydrogen production with a simple process that removes waste materials present in the water.”
Pitchaimuthu and his team have developed a nanoscale material – a particle that is one in 10,000th the diameter of a human hair – to allow distillery wastewater to replace fresh water in the green hydrogen production process. Globally, some 20.5 billion litres of fresh water is used in the process currently.
The nanoparticle, called a nickel selenide, treats the wastewater and, in the team’s research, produced similar or slightly higher quantities of green hydrogen from the wastewater, compared to the results from fresh water.
The research is published in the Royal Society of Chemistry journal, Sustainable Energy & Fuels.
“Using industry wastewater means we can reduce the extensive freshwater footprint associated with green hydrogen production,” Pitchaimuthu said.
The next steps for the research team include developing their own electrolyser prototype and scaling up production of their nickel selenide nanoparticles. They will also be analysing the distillery wastewater to discover whether other materials of value could be salvaged from it, alongside hydrogen and oxygen.
A new report by the Scotch Whisky Association (SWA) this week revealed that the industry supports 66,000 jobs across the UK, of which 41,000 are in Scotland. The industry is now responsible for generating £3 in every £100 of Scotland’s total gross value added (GVA), and is the second most productive sector in Scotland, ranked just behind energy including renewables.
