Scientists help turn whisky waste into valuable goods

A new method of extracting valuable bio-based chemicals from whisky distillery waste streams could revolutionise production, worth up to £90 million to global chemical manufacturing markets.

Scientists at RIPCELL, a chemical company, are collaborating with researchers at the University of Aberdeen to demonstrate the feasibility of recovering high-value compounds such as lactic acid from pot ale and spent grains – byproducts of the first and second stages of the whisky distillation process.

These extracted chemicals can find applications in industries such as pharmaceutical, food and beverage, and cosmetics, which typically rely on unsustainable petrochemical-derived ingredients.

The project used samples of waste streams provided by the whisky company Chivas Brothers from twelve of its distilleries across Scotland.

The research team developed a process that uses a separation technique called liquid chromatography to initially isolate and extract higher-value acids from pot ale. This process has now been adapted to extract additional solvents from the yeast lees.

While residue from pot ale is usually used for low-value purposes such as animal feed, yeast is currently discarded. Up to 10 liters of yeast are produced per liter of whisky, and due to different distilling processes, water sources and raw materials, byproducts from different distilleries contain different chemical compounds.

In addition, a life cycle analysis of the process was conducted to quantify its environmental impact. The results showed that bio-based chemicals produced using this method have a significantly lower carbon footprint than those produced using traditional petrochemical routes. It is estimated that the new manufacturing process for target chemicals could reduce industrial emissions by 392 million kg of CO2 worldwide.₂ Equivalent per year.

Following the success of the feasibility study, the team’s next phase will be to scale up the separation process to demonstrate its feasibility on an industrial scale.

Dr Eve Wildman, founder of RIPCELL, said: “The Scotch whisky industry produces around 2.6 billion litres of wastewater every year, so the potential of this process is huge. For decades, the majority of these byproducts were used as animal feed, but we have found a new, more valuable option for treating lees that could transform the way distilleries handle and process their residues.

“At the same time, this could be a game changer for the chemical industry. By taking a sustainable approach to producing key compounds and avoiding fossil fuels, RIPCELL can help reduce greenhouse gas emissions from the production process. For every kilo of biochemicals produced, we can save 1.59 kg of harmful greenhouse gas emissions.”

Dr Liz Fletcher, Director of Business Engagement at IBioIC, said: “This project is an excellent example of how we can create economic value through a circular approach to by-products and the application of biotechnology. For both whisky producers and the chemical industry, this process represents a significant step forward in reducing the environmental impact of production. We look forward to supporting RIPCELL in its next steps to bring the process closer to commercial application.”

Dr Alan Mccue, Lecturer at the University of Aberdeen, added: “The idea of ​​using wastewater from a traditional industry such as whisky production to recover bio-based chemicals is highly innovative. It is great to see Scottish heritage being linked to sustainable chemical production. The results of this project are really exciting and I look forward to supporting RIPCELL in the next stages of its development.”