(650b) Evaluating the Environmental Impact of Circular Economy Strategies in Biobased Industries Using a Hybrid Input-Output Model Built on Process-Driven Physical Data

Predicting structural changes to the physical and monetary economy from industrial-scale material reuse is one limitation to designing closed loop networks and understanding the full impacts of circular economy strategies on the environment. Economic input-output (IO) analysis has been adapted to estimate the environmental impact arising from a certain level of economic activity, most commonly through environmentally extended input-output (EEIO) analysis, which assumes a proportional amount of energy or material will be produced given changes in economic output, regardless of production scale. Hybrid IO models, or mixed-unit IO models, address the inaccurate assumption of price homogeneity across industries in EEIO analysis by explicitly recording non-monetary exchanges between sectors instead of recording only the direct non-monetary impacts associated with an additional dollar of sector output. Trade or other survey data is often used for the purpose of creating hybrid IO models, if available, though production process models could also be used with the potential to more accurately characterize flows between industries and identify opportunities for substitution of inputs with suitable byproducts. This work leverages the integration of two cloud-based platforms for automated generation of economic and physical input-output tables, the US IELab and PIOT-Hub, respectively, to explore circularizing the flows between industries in a hybrid IO model for a small region of the United States. The environmental footprints resulting from demand for biobased energy, chemical, and agricultural industries are compared to these industries’ footprints once suitable waste flows are reintegrated into the economic structure as potential commodities. Physical data on the major biomass, nutrient, and industrial chemical flows associated with farming, fertilizer manufacturing, and biodiesel production are obtained from the PIOT-Hub; the PIOT-Hub employs mechanistic engineering models to generate PIOTs at any scale with reliable data validation and reproducibility. Analysis of the conventional versus circularized economic structure illustrates how closed loop supply networks may impact the total throughput and environmental impact of these important biobased industries. This work also demonstrates an application of the recently developed PIOT-Hub that could be suitable for either research into the material footprint of industrial networks, or to strengthen corporate environmental impact accounting and claims.