Inventory & Characterization of Alberta Pulp Mill By-Products

Trevor April
Biological Sciences, Northern Alberta Institute of Technology, Edmonton, Alberta, Canada

Most of the by-product streams generated by the pulp and paper industry are well documented and include waste fibers (virgin and effluent waste), wood ash, WWTP sludge, and lime mud, as well as several chemical by-products including tall oil, lignin, hemicelluloses, terpenes, and methanol. However, there is little aggregate information on the quantities of these by-products generated by the different Kraft and TMP mills in Alberta. The different processes used to make pulp (i.e., Kraft versus mechanical) and the variance in fiber source (i.e., softwood versus hardwood) among Alberta mills results in variation in the composition and amount of by-products from one facility to another. Furthermore, the handling of these by-products also varies amongst the different facilities. For example, some facilities collect and extract specific components (e.g., methanol, lignin), whereas other facilities send them directly to kilns/boilers/landfill as a means of disposal or to recover limited amounts of energy. Given the competitive global market for pulp products, Alberta mills must look for ways to offset pulp-production and disposal costs, and establish new revenue streams from their existing processes. If mills are able to effectively separate the different by-product streams, there is significant potential to repurpose them into value-added chemicals, materials, and biofuels. Improved utilization of these by-products in Alberta requires the development of integrated biomass characterization, logistics, and information systems. To help establish baseline information, the project was conducted in two phases: (1) inventory and volumetric assessment of pulp by-products; and (2) detailed compositional analyses of select by-products to help determine their chemical and physical properties. The volumetric and compositional data will be used to aid the Alberta forestry industry, government, and researchers in identifying suitable transformative technologies and determining the best value-added opportunities for their waste streams.