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October 2007

Breweries turn waste into energy
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Dwayne Westfall, professor in the department of soil and crop sciences at Colorado State University in Fort Collins, Colorado, is working to make the brewing industry more energy efficient by developing new sources of renewable energy.

St. Louis-based Anheuser-Busch Companies Inc. (Anheuser-Busch) contacted Westfall last winter and asked whether it would be possible to produce biofuel crops at the brewery’s land application site located near the university. Anheuser-Busch has been using effluent water leftover from the brewing process to grow crops like corn, wheat and forage crops at the site.

Merrick & Co.s facility processes approximately 27 million gallons of waste per year and produces roughly 3 million gallons of fuel-grade ethanol.

Westfall has been working with Anheuser-Busch since 1986. “It is a textbook example of a very environmentally friendly, argonomically sound, land application site, where a product that is classified as waste is used for beneficial crop production,” he said.

Westfall and his colleague Jerry Johnson, an extension specialist and research scientist at the university, started testing a variety of different crops this spring to determine whether it is possible to grow biofuel crops at the land-application site.

Johnson said that they would probably be in the testing phase for at least a year before determining the right crop for the environment, which contains a lot of nitrogen from the brewing process. “We are going to start screening biofuel crops by species and then narrow it down to adaptive varieties for that specific environment,” he said.

University of Florida researchers are conducting similar studies at the company’s brewery in northern Florida for cellulosic ethanol production from native grasses.

Anheuser-Busch hopes to obtain 15 percent of its fuel use company wide from renewable sources, compared to its current level of 8 percent obtained from renewable sources.

The brewery is already utilizing renewable energy through a system it calls Bio-Energy Recovery System technology, an anerobic method of processing brewing-related wastewater and capturing the resulting biogas. The technology is installed at 9 of Anheuser-Busch‘s 12 breweries in the United States, supplying 15 percent of its on-site energy needs.

Almost 1,888 billion British thermal units were generated through the use of the technology in 2006, enough to heat more than 25,000 homes, according to Anheuser-Busch.

Joseph Romm, a senior fellow at the Center for American Progress in Washington D.C, said that Anheuser-Busch is just one of many companies looking for ways to save energy. He wrote about the technology in his book, “Cool Companies: How The Best Businesses Boost Profits and Productivity by Cutting Greenhouse Gas Emissions”.

“The pursuit of energy-saving technology and improved processing has become a big business, not only in part because oil and natural gas prices have soared, but also in part because of the overall growing awareness of global warming,” Romm said.

“I think they are doing it because it makes economic sense. It generates less waste, often saves energy and reduces pollution and turns out to be cost effective.”

Molson Coors Brewing Co., headquartered in Montreal, Canada, is also providing various waste streams at its brewing facility in Golden, Colorado to produce alternative fuel.

The facility, operated by Aurora, Colorado-based Merrick & Co., doubled the capacity at the plant in 2005. It processes about 27 million gallons a year of various waste streams and produces about three million gallons of fuel-grade ethanol at the plant.

“It reduces the waste streams that are generated in the brewing process, which either have to be land farmed or processed at a wastewater treatment plant. There is a cost associated with processing waste streams,” said Steve Wagner, vice president at Merrick.

“It significantly reduces the loads to the wastewater treating plant. In addition to that, it makes money. That’s a revenue stream that otherwise wouldn’t be there.”

Wagner said that Merrick might start this process for Coors at various other sites. The company, which provides architecture, civil engineering, facilities engineering and process engineering services, is also talking with other breweries about the process.

“We have the industry’s attention with fuel prices the way they are. The business arrangements have yet to be defined. But it sure makes economic sense,” Wagner said.

With yet a different process, London-based SABMiller Plc., is using a by-product of sugar production to produce electricity at its brewing and carbonate soft drink operation in Honduras. The cogeneration project generates enough energy for powering the sugar mill. It also delivers surplus energy to the country’s national grid system.

Mario Hernandez, general manager of the sugar division at SABMiller Honduras Central America, said the sale of electricity gives the facility a profit of $2 million.

At full capacity, the facility is expected to generate 15,000 megawatts per crop.

The fibrous by-product from the sugar production, known as bagasse, is often of little use to the sugar industry. It is often dumped in large piles for later incineration.

The process at the facility in Honduras involves the oxidation of the biomass with excess air in a process that yields hot gases that are used to produce steam in boilers.