The Liberty Paper Mill in Becker, Minnesota is about to take recycling to a new level. The plant already recycles old corrugated containers into new paper products. Its next step is to supply the power to run itself.
Wastewater to Energy
The process involves using anaerobic bacteria to convert methane from its wastewater into electricity. The use of this type of biotechnology is not new. However, it is innovative in that an industry that is already helping the environment is moving forward to provide additional benefits for itself, the city’s wastewater-treatment plant and all of its partners.
Using methane to produce energy cuts back on emissions. Even though emissions are much less than carbon dioxide, methane has 21 times more the global warming potential. The primary sources of methane emissions are natural-gas systems, livestock and landfills. The Liberty Paper Mill project offers a way to cut back emissions from some of these sources.
How It Works
Harnessing methane is not a new process. The Cow Power program, part of the Central Vermont Public Service (CVPS) project, is another example of a mutually beneficial program for dairy farmers and customers. Both projects use anaerobic bacteria digesters. The decomposition process of either the wastewater or manure releases heat and methane, which are then captured to generate electricity.
Benefits to the Industry
The overriding benefits for the paper mill are that it reduces costs and its carbon footprint. A successful project of this scale also shows industry as a whole that such savings are possible. It creates goodwill in the community, especially when energy savings come back to the customer. As companies seek to reduce their expenses, looking in unlikely places such as wastewater offers a unique way to solve several problems, while also providing value to the community.
The Liberty Paper Mill project is slated to be operational by the end of 2012. As a first for Minnesota, the project is sure to attract the interest of both the private and public sector. It can lay the groundwork for future solutions to help control fossil fuel usage and greenhouse gas emissions. The addition of a water pretreatment plant with a bio-gas generator will contribute significantly to its green practices of recycling over 250,000 tons of corrugated containers each year.