Toward more sustainable whisky production

SCOTCH is one of Scotland’s iconic products, with about 109 distilleries licensed to produce the whisky.  As of May 2013, Scotland exported 96 million cases worldwide, according to the Scotch Whisky Association (SWA).

Made purely of water, yeast and barley, Scotch by tradition takes at least three years to mature in oak casks, otherwise it cannot be legally sold as whisky. In making this popular drink, much of what is produced by the end of the ageing process is by-product. In fact, only 10% ends up in bottles, and the rest is waste. That much waste from the industry is equivalent to 500,000 metric tons of residual solids called draff and 1.6 billion litres of pot ale, every year. These by-products are usually spread on agricultural lands, turned into low-grade animal feed or discharged into the sea.

Butanol, draff (used barley grains), and pot ale (copper-containing liquid from stills), waste from Scotch-making, can be converted to biobutanol 

To make Scotch production even more sustainable, Celtic Renewables has developed a way to turn dregs into fuel. The start-up company has refined a process that takes from a very old fermentation technique that converts molasses and other sugars into chemicals. 

The company now uses it to convert draft and pot ale into acetone, 1-butanol and ethanol. The latter two can be used as fuel. The company is scaling up its process with help from the U.K. Department of Energy & Climate Change, private funds and Bio Base Europe. The company hopes to get a commercial facility up and running, according to an article in Chemical & Engineering News (C&EN), the weekly news magazine of the American Chemical Society. (Photo courtesy of Celtic Renewables)