Authors

Abstract

Aluminum and steel represent the two most dominant metals in light duty vehicles, yet the flowsof these materials into the American automotive industry have not been well characterized. Thisstudy proposes and implements a method for analyzing the flow of these metals into the automotive industry. We create a framework for performing regionally linked, sector specificmaterial flow analyses and use this framework to trace flows of aluminum and steel entering theAmerican automotive industry, focusing on flows downstream from raw material production. Weshow 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%), nearly all from Quebec (69%). Further upstream, alumina and bauxite originate mostly from Brazil, Australia, and Jamaica. We also show that finished automotivesteel is sourced primarily from the RFC (63%) and SERC (20%) regions. The crude steel supply similarly originates mainly from the RFC (69%) and SERC (7%) regions. Upstream rawmaterials including coke, coking coal, iron ore, lime, and steel scrap are primarily sourced from the U.S. with only direct reduced iron and pig iron used in electric arc furnace steel production coming mostly from outside the U.S. The framework developed here allows for increased spatial resolution of material flows, which can be used to develop more specific life cycle impact factors for life cycle assessments.