Scotland is famous for making (and drinking) large amounts of whiskey, so much so that the local whiskey industry creates about 3 million tons of waste every year. In fact, as little as 7 percent of what comes out of a distillery is actually whisky; the rest is draff, the sugar-rich barley kernels that aid the fermentation process, and pot ale, a yeasty liquid created during distillation. Both have no commercial value, costing distillers large sums of money to dispose of.
Celtic Renewables, a start-up company in Edinburgh, has created a new process that combines both draff and pot ale to produce biobutanol, an alternative fuel that can be used to power any internal combustion engine without modification. It can also be blended with gasoline or diesel fuel, creating a greener, more sustainable blend of petrol. Because the process depends on waste products, this biofuel uses no food stocks like corn that could otherwise be used to feed people.
The basic chemistry behind the system is called ABE fermentation, which stands for acetone, butane and ethanol. The process is similar to brewing beer, and starts by mixing draff and pot ale into a slurry that’s then fermented, producing hydrogen and CO2. The broth is then distilled to make butanol, acetone and ethanol. The leftover solids are separated and dried, then treated to produce high-grade animal feed. Whiskey waste has been used to power other distilleries and even the Nissan LEAF, but actually powering cars using leftover whiskey waste? That’s something else entirely.
Celtic Renewables CEO Mark Simmers says the company is currently working with Tullibardine whisky distillery in Blackford, Scotland, and the Bio Base Europe Pilot Plant in Ghent, Belgium, to scale-up its process to commercially viable levels. “We hope to commence the planning and development of our first commercial scale production plant in 2015,” says Simmers.
The concept is brilliant – take something that is otherwise thrown away and turn it into fuel and animal feed. The distillers used to pay to have the stuff hauled away and are happy to give it to Celtic Renewables for free. Since Europe will require 10 percent of all fuels sold by 2020 to be biofuels, the timing could not be better for Celtic Renewables.