By Stan Stelter
Bismarck, ND – Add waste wood to lignite coal and burn the mixture to generate both heat and electricity. And, in the end, you have less waste to bury in a landfill.
That is at the heart of a cogeneration project being tested for installing at the North Dakota State Penitentiary. Officials say it looks good technically, but no final decision has been made yet.
Darren Schmidt of the Energy and Envionmental Research Center at UND says testing has turned out well using wood chips, which come from tree-trimmings and other waste wood now being taken to the Bismarck landfill. Schmidt says this is a realistic opportunity to use renewable fuel for energy.
"A lot times alternative energy studies are focused on things that don't pay off economically, but this is an example of a technology that can pay off economically."
To do the project, Schmidt says biomass processing equipment, boiler modifications and a steam turbine facility would be needed. That would cost $1.7 million, which could be paid back in about 15 years through energy savings. Initial funding for the project may come through several sources, including the Department of Energy, state Division of Community Services and state general funds.
Plant services director Dick Frohlich of the state Corrections Department says recent tests burned 75 percent biomass with 25 percent lignite."Right now I think we're at a 75 percent biomass, 25 percent coal, and by doing that the existing boiler would certainly do a fine job. The stack emissions wouldn't be a concern. In fact, emissions would be lowered, the sulfur emissions that are a concern." Because the boilers would be used year-around for power, Frohlich says the amount of lignite used would nearly double with this project.
State energy engineer Darin Scherr says the project looks good. "First of all, we think it would be a good project for the State Pen and the state in general. You know, it gives us the opportunity to increase the usage of a North Dakota product -- lignite coal, and also reduce the volume in a local landfill."
A decision could come with a final report on the project in December.