Reducing Emissions from Open Burning through Biomass Gasification


Minnesota forests produce 2.4 million tons of wood waste per year. A significant fraction of that biomass is burned in open piles resulting in harmful pollution, generating unnecessary carbon dioxide emissions and wasting energy. The Minnesota DNR estimates that 35,000 tons of piled woody biomass was burned in Southwest MN this winter alone emitting approximately 128,000 tons of CO2. This project proposes 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. Our 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 that have high price fluctuation. State parks are ideal sites for distributed gasification due to their low energy use and remote location. The three primary goals of our project are:

1) Quantify the pollutant emissions reduction potential of a reliable, small-scale, locally operated combined heat and power gasifier system operated on wood chips compared to open burning of the same quantity of biomass. Measured emissions will include oxides of nitrogen (NOX), hydrocarbons and particulate matter. 
2) Estimate the carbon emissions reduction potential of small-scale gasification for distributed heat and power for remote applications like state parks and rural residences. CO2 emissions will be measured from the gasifier system and equivalent carbon emissions avoided from fossil fuel burning will be calculated. 
3) Publically promote the use of distributed gasification technology by demonstrating a 20 kW combined heat and power gasification system at a MN DNR facility and posting energy savings on the DNR's Energy Smart website (