How whisky waste can replace fossil fuels on road to net zero

As Glasgow welcomes leaders from around the world to the United Nations climate summit, COP26, the founder of a Scottish biotech company is calling for action, not targets.

Professor Martin Tangney's company, Celtic Renewables, turns left-over waste from whisky making into the kind of everyday chemicals that are normally made in oil refineries, without drilling for fossil fuels. This includes a novel gasoline alternative which is a direct replacement for the petrol that powers most traditional cars.

"This has to be the COP where we stop talking about why we need to tackle climate change and tell everybody how; how we do it, how we pay for it, how's it going to happen. A roadmap. A strategy. Not an exercise in target setting," Tangney, founder and president of Celtic Renewables, told Reuters at the company's demonstration plant in Grangemouth, near Edinburgh.

Whisky is made from barley, yeast and water and leaves behind spent barley grains, known as draff, and a sugary water called pot ale.

The waste is often disposed of as an animal feed or even pumped into the sea. Recently, scotch whisky maker Glenfiddich announced they were processing their waste to produce methane which is then used to power their specially adapted delivery trucks.

Celtic Renewables says their product is a direct replacement fuel for a standard, unmodified, petrol engine.

"We can take residues from industries such as the whisky industry and convert them into high value products, namely butanol, which is actually being used to power this car right now," Tangney said while driving through the Campsie Fells, north of Glasgow, after filling the car's tank with their biofuel.

The process of converting the waste, known as ABE fermentation, produces acetone, butanol and ethanol, chemicals that are used daily in everything from fuel and food production to medicine and cosmetics. Chemicals that could be used long into the future, as long as they are produced in a sustainable way, according to Tangney.

"Our view is not to tell everybody all the things you can't do. It's show people how we can innovate to do them differently," he said.

ABE fermentation was at one point a huge global industry but finally shut down because of competition from petrochemicals and the cost of raw materials, a problem Celtic Renewables say they have solved with their patented process which relies on organic waste rather than high value crops.

"This is made from living carbon. Essentially it's from a residue from an industry that's one of the most important industries in the Scottish economy and we can take their residues and turn them into something we need right now made from sustainable resources," Tangney said.

The Grangemouth demonstration plant can produce 1 million liters of advanced sustainable biochemicals from 50,000 tons of draff and pot ale and other raw materials such as potatoes, or almost any organic waste.

The company now plans to build 5 large scale refineries around the world in the next 5 years and is calling on governments and investors to back them.