Reducing Emissions from Open Burning through Biomass Gasification

Project summary:

Minnesota forests produce 2.4 million tons of wood waste per year. A significant fraction of that biomass is burned in open piles, which results in harmful pollution, generates unnecessary carbon dioxide emissions, and wastes energy. The Minnesota Department of Natural Resources (DNR) estimates that 35,000 tons of piled woody biomass was burned in Southwest MN this winter alone, emitting approximately 128,000 tons of carbon dioxide (CO2). This project proposes using distributed gasification for combined heat and power as an alternative to open burning of wood waste in Minnesota. Large-scale, high efficiency gasification systems have been demonstrated in regions of MN with high agricultural intensity. However, large-scale gasification is too expensive for wood waste produced over a large geographic area due to collection and transportation costs. This study's hypothesis is that small-scale (less than 50 kW) gasification systems can produce energy from wood waste nearer to its source, improving the economics of gasification while reducing emissions of pollutants and reducing reliance on fossil sources of energy like propane (which have high price fluctuation). State parks are ideal sites for distributed gasification due to their low energy use and remote locations. Researchers are measuring emissions from a donated gasifier-generator system from All Power Labs at the University of Minnesota (UMN) Engine Research Facility during the first year of the project. The system will then operate on dried wood chips in the DNR's Regional Office Facility in New Ulm, MN, augmenting their newly-installed photovoltaic array and providing electricity during times of peak energy demand. The system will be returned to UMN at the end of the project. This two year program has the potential to have a significant impact in Minnesota by illustrating the benefits of small-scale, distributed gasification to avoid open burning of woody biomass while saving energy and reducing emissions.