St. Paul Port Authority favors biogas to power Rock-Tenn because it is a renewable technology and would keep jobs in St. Paul.
Corn and manure might be part of the solution to keeping the Rock-Tenn paper recycling plant -- and its 475 jobs -- in St. Paul.
They're ingredients to help make biogas, which the St. Paul Port Authority on Monday revealed as its preferred energy source to power Rock-Tenn, the state's largest paper recycler. The Port Authority says the biogas could be from 10 to 20 percent cheaper than natural gas.
It's a milestone decision after a year of studies, lectures and nearly two dozen public meetings on finding the most practical, cost-effective and environmentally friendly energy source. About 40 people attended Monday night's meeting of the citizen advisory committee, during which the news was announced.
Rock-Tenn has been burning a mixture of natural gas and fuel oil since it lost access to steam energy when Xcel Energy's coal-fired plant on the Mississippi closed down. At peak times, the recycling facility uses as much energy as it would take to power about 20,000 homes.
Biogas comes from anaerobic digestion, a process that decomposes organic material with microbes. The process reduces the emission of methane, a harmful greenhouse gas. A facility in rural Minnesota would be used, taking ethanol byproducts and manure for anaerobic digestion. The clean-burning biogas would be sent through a pipeline and used in Rock-Tenn's existing burners.
Depending on the method and material, anaerobic digestion would help rural communities manage waste, clean water and help produce nutrient-rich soil, according to the Port Authority's draft report.
It's also a renewable technology that will grow and allows Rock-Tenn to use existing infrastructure, said Peter Klein, vice president of finance for the Port Authority.
Environmentally, it's a great solution, said Bob Carpenter, assistant general manager at Rock-Tenn.
But to make the option work economically, Klein said, the Port Authority needs to secure a loan guarantee from the U.S. Department of Energy. Then, the cost of moving gas through the pipeline needs to be reduced and carbon credits need to be used. Finally, Rock-Tenn would have to stay in St. Paul for 10 years.
The citizens panel will take some time to digest the study and make a recommendation of its own. The panel, expected to make its recommendations to the City Council by fall, includes community, business and environmentalist members. There will be public meetings.
The Port Authority also shared its second and third options: a biogas-turbine combination that would allow for the sale of energy from the turbine, and gasification of renewable biomass crops.
"The port's proposal would provide a critical investment in a promising technology that would allow us to lead the way toward energy independence while keeping good jobs in our community," St. Paul Mayor Chris Coleman said in a prepared statement Monday night.
The Legislature gave $4 million to the Port Authority to study energy alternatives for Rock-Tenn. The study began last August.
Chris Havens • 651-298-1542