GOING WITH THEGRA
Auto Express heads to Edinburgh to learn how residue from whisky production could be used to power your car in the not too distant future
HISTORY has a funny way of repeating itself. Go back a few hundred years, and it was French philosopher Voltaire who said Scotland is where “we look to for all our ideas of civilisation”. Anyone visiting Scotland today could say exactly the same. Not only was it the first country in the UK to lower its blood-alcohol limit to cut down on drinkdriving, but it’s also actively pursuing new means of meeting ambitious EU targets of reducing emissions by 80 per cent by 2050. And part of this involves using the country’s most famous export, whisky, to the benefit of the motorist.
Celtic Renewables is the Edinburgh-based biotechnical company spearheading the process of turning waste from whisky distilleries into biobutanol – a viable substitute for petrol and diesel that doesn’t require any changes to engines. If it all goes to plan, in a few years we could see a million litres of biobutanol replacing conventional fuel, offsetting thousands of tonnes of CO2. Auto Express headed to the company’s HQ to meet with founder and president Professor Martin Tangney to find out more.
“When Henry Ford mass produced the Model-t, he designed it to run on bioethanol. Ford was a biofuel man,” explains Professor Tangney. Ford’s vision was to farm the land to grow crops that would feed people and produce ethanol to power the vehicles that then farmed the land. “He had the idea of creating circular economy, something everyone talks about these days,” adds Tangney.
It was a similar philosophy that had the professor, a microbiologist by training, looking towards the whisky industry in 2006. “The whisky industry has been around for hundreds and hundreds of years,” he tells us.
The process of making whisky remains simple, though. “Pure malt whisky is made out of three ingredients: barley, water and yeast. The barley seeds are first left to germinate to release sugars. The distillery then adds hot water to extract the sugars, especially the glucose. It finally adds yeast which converts glucose into ethanol,” Tangney explains.
At this point, the distilleries are left with a beer-like product; and to turn it into whisky, it is distilled in a copper still and left to age. However, only 10 per cent of the output from distilleries is whisky. The remaining 90 per cent is waste, such as the copper-contaminated beer called pot ale and barley that has been starved of sugars known as draff.
“This happens 24/7 all over the country. In Scotland, over two billion litres of pot ale is produced each year, along with three-quarters-of-a-million tonnes of draff,” Tangney says. Currently, much of this waste is dumped into the sea, where strong currents carry it elsewhere, or is used as a thinner for cattle-feed, but there’s plenty more that pot ale and draff can be used for – and particularly for motorists.
Celtic Renewables uses the century-old Weizmann ABE fermentation process with a modern twist and some clever patents to create biobutanol. The draff and pot ale are treated with heat and acid and fermented to create a broth. During fermentation, bacteria convert the broth into butanol, acetone and ethanol. Although ethanol has been a certified biofuel for years, it was only in 2009, after years and millions of miles of testing, that the UK Renewable Transport Fuel Obligation recognised butanol as a biofuel.
Helpfully, biobutanol’s energy content is closer to that of petrol compared with bioethanol, meaning a car can run on it without needing a different engine. With a better energy content than ethanol, there’s little compromise in fuel economy and performance, plus it can also be used in higher-blend concentrations without harming the engine. A 16 per cent blend of biobutanol in your tank offers motorists the same fuel economy as a 10 per cent