Scottish start-up transforms whisky by-products into liquid assets
A new method to extract valuable bio-based chemicals from whisky distillery waste streams could transform manufacturing and have potential applications in sectors including food and drink.
The extraction of chemicals is forecast to be worth up to £90m in global chemical manufacturing markets.
Scientists from Ripcell, a chemical manufacturing business, are working with researchers from the University of Aberdeen to demonstrate the feasibility of recovering high-value compounds, such as lactic acid, from pot ale and spent lees – co-products of the first and second stages of the whisky distillation process.
The project was supported with funding from the Industrial Biotechnology Innovation Centre (IBioIC), with samples of waste streams provided by whisky group Chivas Brothers from 12 of its distilleries across Scotland.
The research team developed a process use liquid chromatography to isolate and extract higher-value acids, initially from pot ale. It has now been adapted to retrieve additional solvents from spent lees.
While residue from pot ale is typically used in low value applications such as animal feeds, spent lees are currently discarded. Up to 10 litres of spent lees are generated for every litre of whisky made, and due to variations in distillery processes, water sources, and raw materials, co-products from different distilleries contain different chemical compounds.
A life cycle analysis of the process was also completed to quantify its environmental impact. The results showed that the bio-based chemicals produced through this method have a significantly lower carbon footprint compared to those produced through traditional petrochemical routes. Estimates suggest that on a global scale, the new manufacturing method for target chemicals could reduce industry emissions by 392 million kg of CO2 equivalent per year.
Following the success of the feasibility study, the next phase for the team will involve scaling up the separation process to prove its viability at an industrial scale.
Dr Eve Wildman, founder of Ripcell, noted that around 2.6 billion litres of wastewater is produced from the Scottish whisky industry every year, so the potential of the process is “huge”.
“For decades, the majority of these co-products have been used as animal feed, but we have found a new, more valuable option to deal with spent lees that could change the ways in which distilleries manage and process their residues,” Dr Wildman explained. “At the same time, this could be transformational for the chemicals industry. By taking a sustainable approach to manufacturing key compounds, rather than using fossil fuels, Ripcell can help to reduce greenhouse gas emissions from the production process. For every kilo of bio-chemicals produced, we can remove 1.59kg of harmful greenhouse gas emissions.”
Dr Liz Fletcher, director of business engagement at IBioIC, hailed the project as a brilliant example of how to add economic value by taking a circular approach to co-products and applying biotechnology.
“For both whisky producers and the chemicals industry, this process marks a significant step forward in reducing the environmental impact of manufacturing. We look forward to supporting Ripcell throughout its next steps to bring the process closer to commercial application,” Dr Fletcher added.
Dr Alan Mccue, senior lecturer at the University of Aberdeen, added: “The idea of utilising wastewater from a traditional industry like whisky production for the recovery of bio-based chemicals is highly innovative. It’s great to see Scottish heritage being linked to sustainable chemical production. The outcomes of this IBioIC funded project are really exciting, and I look forward to supporting Ripcell in the next stages of its development.”
