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Becker plant turns wastewater into energy

  • Article by: PAUL LEVY
  • Star Tribune
  • March 20, 2012 - 4:17 PM

A water pretreatment plant with a bio-gas generator -- projected to capture enough methane gas to power the mammoth Liberty Paper mill in Becker -- could change the way Minnesota turns waste to fuel.

The $15 million Liberty plant, expected to be running by year's end, is "a first for Minnesota," said a St. Paul Port Authority executive. The 550,000 gallons of water the mill uses daily to recycle old corrugated containers into new paper for packaging will be pretreated at the on-site plant before being routed to Becker's industrial waste water-treatment plant.

Not only will the new process harness the methane gas needed to power a plant that recycles more than 250,000 tons of old corrugated containers each year, it also will ease the burden of the city's waste water-treatment plant, said Sherburne County Administrator Brian Bensen.

"It's a very unusual project for Minnesota," said Pete Klein, vice president of finance with the St. Paul Port Authority.

"There are not many anaerobic digester facilities out there, and this one will start a trend in a new way to use waste," Klein said. "Instead of sending it down the river, we can actually use it to make energy and reduce the need for fossil fuels."

The project was spearheaded by Liberty Paper, a branch of Minneapolis' Liberty Diversified International. But the St. Paul Port Authority, established by the Minnesota Legislature in 1932 and given added power to redevelop land in 1957, is one of several public and corporate investors in the pre-treatment facility. Others include Xcel Energy, Becker's largest employer, as well as Sherburne County, the city of Becker and the Initiative Foundation, a regional resource on job creation and economic development.

The concept of anaerobic digesters systems is not new. Ten years ago, a workshop on anaerobic digesters was held in St. Cloud. The St. Paul Port Authority is aware that the Liberty anaerobic digester will not be Minnesota's first -- there may have been others, "possibly on dairy farms," Klein said.

"But the Liberty plant is big enough and financially and environmentally sound enough that it may be the one that starts a trend in ... converting waste to power," Klein said.

Saving trees

Liberty's parent company has been around for nearly a century, but the paper mill in Becker wasn't established until 1995. Unlike other mills, Liberty doesn't turn trees into pulp, explained General Manager Larry Newell, who has been with the Becker facility since its inception.

"We take old corrugated boxes, remove the contaminants and any undesirable material and make paper out of it again," Newell said. "It's always been a unique sustainability story."

The relationship that Liberty has held with Becker and Sherburne County is also one that has benefited all partners.

Before Liberty arrived in Becker, it let the city and county know that it needed a structure to process its water, Newell said. Becker built a treatment plant "to get us here," Newel said.

More recently, Liberty realized it needed to further recycle products that already had been recycled -- and to do it in a way that made environmental sense. Again, the company explored the public-private landscape.

People's plant

"Your garbage from landfills breaks down to produce methane gas, a fuel source," Newell said. "What if we could put our waste water through a converted generator and convert that methane to electricity?"

Eight months ago, Sherburne County and the Initiative Foundation got together "with a pretty varied group," Bensen, the county administrator, recalled.

For Becker, a city 42 miles northwest of Minneapolis that is best known to some folks as a place to buy furniture, Liberty Paper is one of the city's three top employers, said Mayor Dave Graning, who was a member of the city's economic development team when Liberty arrived in the city.

"Liberty Paper is a recycling operation to begin with," Graning said. "What they're doing is taking an already-recycled product and recycling it even further. You couldn't find a more complete recycling operation."

Paul Levy • 612-673-4419

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