Glendullan malt whisky distillery goes ‘green’ with on-site anaerobic digestion

Clearfleau, which provides on-site anaerobic digestion (AD) solutions for food and beverage companies, today announces handover of its latest bio-energy plant at Diageo’s Glendullan distillery.

This bio-energy facility is an example of how the whisky industry can embrace the ‘circular’ economy. By generating bio-energy from its waste products, Diageo is showing how one of Scotland’s most traditional industries can deliver carbon savings and wider environmental benefits.

The Glendullan plant optimises energy output using waste products from the distillation process. The project involved close collaboration between Clearfleau’s in-house design, installation and commissioning engineers, their counterparts from Diageo, and an extended supply chain.

Keith Miller, Distillation and Maturation Director, Diageo, said: “We’re very proud of our record in investing in cutting-edge sustainable technology at our distilleries. The bioenergy plant at Glendullan is the most recent example of how we use innovative technology which harnesses the potential of the natural raw materials we use in the distillation process to generate renewable energy.”

Initial results indicate the Glendullan bio-energy facility is generating 2 million m3 of biogas per year – producing about 8,000MW hours of thermal energy for the distillery, based on processing up to 1,000m3 of distillery waste products on a daily basis.

Clearfleau’s on-site AD technology converts a range of waste products into valuable biogas that generates renewable heat for use in the distillation process while reducing a major overhead, its waste product disposal costs. By reducing costs and benefiting the local environment, Diageo is setting an example to British food and beverage companies (including other distillery sites).

Clearfleau’s unique liquid anaerobic digestion system can achieve a reduction in COD load of greater than 95%, minimising additional treatment required for discharge of cleansed water to the river Fiddich. The facility will also reduce the site’s fossil fuel based energy costs.

Craig Chapman, Chief Executive Officer, Clearfleau, said: “This project, a result of close collaboration between Diageo and Clearfleau, shows how British technology can enable a traditional but energy intensive Scottish business sector to embrace the circular economy, reduce its costs and create a more sustainable basis for production.

“However, wider adoption of this technology requires on-going support for renewable energy. The Scottish and British Government should be working together to support the development of indigenous renewables technologies and their adoption in a range of industry sectors, helping to deliver our long-term sustainability targets.”

Engineering challenges involved developing a plant able to handle higher strength materials such as pot ale, as well as the variability of strength and volume of feedstock being fed to it. They also included the location of the plant on a sensitive location in a valley adjacent to the river Fiddich and achieving the complex water course discharge standards.

Clearfleau’s unique liquid digestion system delivers a reduction in COD load of greater than 95%, minimising additional treatment required for discharge of cleansed water to the river Fiddich. The discharged water is carefully monitored in terms of COD removal, biogas output and microbial performance, protecting the regions’ important aquatic eco-system.

Scottish Office Minister, Lord Dunlop, added: “The commitment to powering distilleries like Glendullan with sustainable energy, recycled from the waste products of the whisky-making process , is also exactly the right thing to do. Good for the planet, good for the whisky industry and good for the Scottish economy.”