Biofuel From Whiskey Waste
June 18, 2013

Startup Uses 100-year-old Technology To Make Biofuel From Whisky Byproduct

redOrbit Staff & Wire Reports - Your Universe Online

Scottish start-up Celtic Renewables is bringing back a once popular fermentation process that it says can be used to produce superior next-generation biofuels from the byproducts of various biological industries.

The company is initially focused on the $6 billion Scottish Malt Whisky industry as a ready resource for developing biobutanol, a biofuel that has 25 percent more energy per unit volume than bioethanol.

Just 10 percent of what flows out of a distillery still is future whisky. The majority of what remains is draff, the residue of the grains of barley, and pot ale, a copper-laden liquid.

Scotland's distillers currently produce 423 million gallons of pot ale and half a million metric tons of draff each year, and the cost of disposing of all that byproduct directly hits their bottom lines.

"They have a major disposal problem," said Martin Tangney, founder and president of Celtic Renewables, in an interview with National Geographic.

The innovative startup aims to convert a "high percentage" of all that waste into biobutanol, which Tangney estimates could create a $90 million biofuels industry.

"One man's waste is another man's gold," he said.

Tullibardine is a distillery about 50 miles northwest of Edinburgh, which produces 528,344 gallons of pot ale and 6,500 metric tons of draff each year, from which they incur $375,000 in disposal costs.

The distillery has agreed to supply Celtic Renewables with feedstock for an ongoing pilot project that will convert the organic matter into useful industrial alcohols like biobutanol.

The conversion process, known as ABE (for acetone-butanol-ethanol), uses the bacterium Clostridium acetobutylicum.

University of Manchester chemist Chaim Weizmann, who later become Israel´s first president, was the first person to isolate and put to use a strain of Clostridium acetobutylicum. He received a patent for the process in 1915.

At the time, the critical product from ABE fermentation was acetone, which was used to make munitions during World War I and later as a solvent to make lacquers. From there, ABE fermentation grew to support a vast, global chemical industry. But by the 1960s, the industry had waned amid competition from petrochemicals.

Interest in resurrecting the process to produce biobutanol surfaced in 2005, when American inventor David Ramey proved the alcohol's value by driving an unmodified 1992 Buick Park Royal across the US fueled by pure biobutanol.

Ramey later founded Butylfuel, which merged with the UK-based firm Green Biologics, which makes biobutanol from a number of feedstocks such as corn, sugar cane, and cellulosic biomass.

In 2006, BP and DuPont announced a partnership to make biobutanol from sugar beets, among other feedstock. But that initiative was slowed by a patent lawsuit that has been resolved only recently.

Meanwhile, Shanghai's Cathay Industrial Biotech is producing biobutanol from cornstarch, while California-based Cobalt Technologies is making it from cellulosic biomass.

The heightened interest in biobutanol is due to its four-carbon molecular structure, which packs 25 percent more energy by volume than ethanol. It also has a lower flashpoint, making it easier to store and handle, and can be burned directly in an internal-combustion engine in lieu of gasoline. But Tangney said the biofuel would likely be blended into gasoline as an additive.

Unlike ethanol, biobutanol can be mixed into gasoline at the refinery without any modifications, and can be blended with both diesel and biodiesel.

Celtic Renewables' version also steers clear of a critical drawback of many conventionally produced biofuels in that it does not require additional land and crops that could be used for food because it is derived from biowaste.

If Celtic Renewables´ concept proves successful, it could help Scotland meet its goal of reducing its national waste stream, which is one of the main reasons the company has received $1.13 million in public grants and private investments, Tangney said. The concept could also be applied to wine- and beer-making, as well as to food, and paper-manufacturing wastes.

The company is roughly halfway through a pilot demonstration that began last fall at the Center for Process Innovation in England. The goal is to produce 2,641 gallons of biobutanol.

The process will also result in two other commercial products — bioacetone, which is used in paints and plastics, and solid waste that can be sold as high-grade animal feed.

Tangney said he is confident the process can be modified to produce a cost-competitive biofuel additive at industrial levels as well.

"It's not like we're inventing something brand new.”