A. Banboukian, D. Kamath, S. Nimbalkar, J. Cresko
Oak Ridge National Laboratory,
United States
Keywords: LCA, LCCA, biorefinery waste utilization, pulp and paper industry
Summary:
The pulp and paper industry (PPI) is an integral part of the manufacturing industry in the United States. Despite the industry’s success in reducing energy use, it remains an energy-intensive industry, accounting for 11% of the manufacturing sector’s energy consumption. There have been many initiatives to decarbonize the PPI and many novel innovations to make it more energy efficient. One of the novel approaches to decarbonizing this industry is through converting existing pulp and paper mills into integrated pulp and paper biorefineries (IPPB) and transforming wastes or lower-value by-products into value-added products. Studies have shown that one of the key value-added products of IPPBs is soil amendment. Soil amendments can be produced from by-products such as sludge, lime mud and dregs. The sludge of PPI mainly consists of wood-fibers, paper products and non-wood fibers; therefore, using it to produce soil amendments can improve soil quality and increase soil organic matter. Lime mud and dregs can also be beneficial to the soil and its quality. In this study, we use life cycle assessment (LCA) and techno economic analysis (TEA) to investigate and compare the costs, carbon, and energy impacts of IPPB-based soil amendments. The objectives of this analysis are to show the environmental and economic impacts of this IPPB-based value-added product, and to identify the main drivers for these impacts. In this analysis, we use the system expansion methodology with substitution to account for the avoidance of conventionally produced products that the IPPB-based soil amendments replace. Our expected results will identify the carbon and energy hotspots in the processes that can be improved and assess what the main environmental and economic impacts hinge on. IPPBs are industrial symbiosis systems that share materials and energy between the production processes of pulp and value-added products. This results in reduced usage of virgin materials, energy use, emissions, and waste generation. Therefore, targeting specific product markets could lead to net improvements in the total environmental impacts of the system. Lower production costs could also contribute to a more competitive market. The value-added products produced can replace petroleum-based, virgin materials, impacting material and resource consumption of multiple industries. Thus, the results of this study can help decision makers with their judgement related to this product as compared to others in the market with respect to their economic and life-cycle impacts.