Eco-nomics: Turning Brewery Waste into Natural Gas

In this Jan. 26, 2011 photo, Eric Fitch holds a Magic Hat glass in front of the digester building at the brewery in South Burlington, Vt. The Vermont brewery is giving new meaning to the idea of green beer. Magic Hat Brewing Co., of South Burlington, is the first site to use a device that turns spent grain from the brewing process into natural gas that is then used to fuel brewing operations. The 42-foot tall anaerobic methane digester, installed last summer, extracts energy from the spent hops, barley and yeast left over from the brewing process. (AP Photo/Toby Talbot)

From Boston.com the story of Magic Hat Brewery's anaerobic methane digester which turns spent grain into natural gas that they then use to fuel the brewery:

Before he started "saving the earth, one beer at a time," all inventor Eric Fitch knew about home brewing was that it could make quite a mess.

Once, he accidentally backed up the plumbing in his apartment building by dumping into his garbage disposal the spent grain left over from his India Pale Ale home brew. The oatmeal-looking gunk choked the pipes in his Cambridge, Mass., building, flooding the basement.

These days, he's doing something more constructive, fulfilling the dream of beer lovers everywhere by recycling the stuff: The MIT-trained mechanical engineer has invented a patented device that turns brewery waste into natural gas that's used to fuel the brewing process.

The anaerobic methane digester, installed last year at Magic Hat Brewing Co. in Vermont, extracts energy from the spent hops, barley and yeast left over from the brewing process -- and it processes the plant's wastewater. That saves the brewer on waste disposal and natural gas purchasing

The 42-foot tall structure, which cost about $4 million to build, sits in the back parking lot of Magic Hat's brewery, where it came online last summer.

Fitch, 37, is CEO of PurposeEnergy, Inc., of Waltham, Mass., a renewable energy startup company whose lone product is the biphase orbicular bioreactor, which is 50 feet in diameter, holds 490,000 gallons of slurry and produces 200 cubic feet of biogas per minute.

Brewers big and small have wrestled with waste issues since the dawn of beer-making. In recent years, they've turned to recycling -- both as a cost-saver and for environmental reasons.

Anheuser-Busch, which makes Budweiser, uses a bio-energy recovery system in 10 of its 12 U.S. breweries to convert wastewater into natural gas that's then used to fuel the brewing process.

New Belgium Brewing Co., in Fort Collins, Colo., captures excess heat from cooling wort and funnels it beneath its loading dock so it doesn't ice up in wintertime. The wort, the liquid made with malt and hot water, is fermented to make beer or ale.

Coors' breweries sell ethanol from their brewing process to refineries in Colorado. Some European breweries dry their spent grain and then burn it, using the heat and energy in their manufacturing process.

Most operations dispose of their spent grain by selling it -- or giving it away -- to farmers, for use as cattle or animal feed.

But PurposeEnergy says its digester is the first in the world to extract energy from the spent grain and then re-use it in the brewery, and all in one place. At Magic Hat, the big brown silo is located about 100 feet from the main complex.

"Feeding it to cattle is pretty direct recycling, especially if you get steak back out of it," said Julie Johnson, editor of All About Beer magazine. "Carting it off as animal feed is pretty common. In this case, by closing the loop at the brewery, this is turning it into savings quite directly for Magic Hat."

[HT: KGW The Square]