Technical Bulletin No. 1016: Greenhouse Gas and Fossil Fuel Reduction Benefits of Using Biomass Manufacturing Residuals for Energy Production in Forest Products Facilities
This study examined the life cycle greenhouse gas (GHG) and fossil fuel-related implications of using various manufacturing biomass residuals for energy production at pulp and paper mills and wood products manufacturing facilities. Woody mill residuals (e.g., bark, sawdust, etc.), wastewater treatment plant (WWTP) residuals, and paper recycling residuals were studied. Results from an earlier study of black liquor were also included and extended. Two product systems were compared: a product system in which the biomass residuals are burned for energy in a forest products industry facility (biomass energy system), and a product system in which the biomass residuals are disposed of and fossil fuels are used instead (non-use system). The systems were compared on the basis of a functional unit of 1 GJ energy output in same form for each system. For each residual type, various scenarios were evaluated, including one (the typical scenario) that best represents the industry average. A variety of residual characteristics were subjected to sensitivity analyses. The impacts of the systems were characterized dynamically, using cumulative radiative forcing attributable to the GHG emissions from each system over time. Impacts were calculated in terms of the differences between the biomass and non-use systems over 100 years, expressed as CO2E, as well as the time required for the net difference in cumulative radiative forcing to reach zero (i.e., the break-even time). Reductions in consumption of fossil fuels were also computed. This report was first published in October 2013, and was revised in 2014.
KEYWORDS: biomass residuals, energy, greenhouse gases, life cycle assessment