Life-Cycle Assessment for Wood-Fired Boilers Used in the Wood Products Industry

Many wood production facilities use wood-based fuels for steam generation for drying wood or pressing boards or panels. This process contributes to the life-cycle impacts of the products produced downstream. Past life-cycle assessment studies of wood products have relied on wood boiler data sets that represent both the paper and the wood products industries as well as on secondary data from the US Environmental Protection Agency primarily based on the potential to emit or collect from an uncontrolled source. Primary data were collected by survey for the material and energy inputs and outputs of wood-fired boilers at lumber and plywood wood production facilities in the Pacific Northwest and Southeast regions of the United States. The results were averaged to create a life-cycle inventory model to represent wood-fired boilers at wood production facilities. Results indicated that regional differences, as well as type of wood waste burned, did not warrant separate boiler data sets for each industry and region. The model is useful for including the effects of steam production in the life-cycle assessment of wood products. The primary data used in the model should better represent wood-fired boilers used in US wood production facilities than existing data sets do.