Regional-level analysis for the material flows and process energy demands of aluminum and steel in the American automotive industry
Aluminum and steel represent the two most dominant metals in light duty vehicles (LDVs), yet the flows of these materials into the American automotive industry have not been closely evaluated. This study proposes and implements a method for analyzing the flows of these metals into the automotive industry. We create a framework for performing regionally linked, sector specific material flow analyses (MFA) and apply it to the material flows of wrought aluminum and steel into the American automotive industry. We then regionalize the process energy demands associated with these flows. We show that automotive aluminum sheet and extrusions are sourced primarily from the NPCC (23%), SERC (20%), MRO (18%), and RFC (13%) NERC regions and a spatially unresolved Local region within the U.S. and Canada (18%). We determine that primary aluminum is largely from Canada (70%), primarily Quebec (69%). Further upstream, alumina and bauxite are mostly supplied by Brazil, Australia, and Jamaica. We also show that finished automotive steel is sourced primarily from the RFC (63%) and SERC (20%) regions. The crude steel supply is similarly dominated by the RFC (69%) and SERC (7%) regions. Most upstream raw materials including coke, coking coal, iron ore, lime, and steel scrap are primarily sourced from the U.S.—only direct reduced iron (DRI) and pig iron are exceptions. Regional distributions of process energy demands for these metals largely coincide with their material flows. Overall, we hope this study helps inform the sustainability of the American automotive, aluminum, and steel industries.
Nate Hua, MS (SusSys)