Perfluorocarbon (PFC) generation at primary aluminum smelters

Abstract

The primary aluminum industry is continually working to improve production efficiency and enhance environmental performance. Through a partnership with the U.S. Environmental Protection Agency (EPA) and the U.S. aluminum industry known as the Voluntary Aluminum Industrial Partnership (VAIP) Program, twelve U.S. primary aluminum producers are focusing on reducing perfluorocarbon (PFC) emissions, CF4 and C2F6. PFCs trap heat in the atmosphere, contributing to the greenhouse effect. To better understand PFC emissions and key factors influencing their generation, EPA through the VAIP sponsored a measurement program for PFCs at seven aluminum smelters. The data show a clear trend toward lower PFC emissions with reduced anode effect (AE) frequency and duration. The scatter in the intra-plant and inter-plant data suggests there may be other operational factors affecting emission rates. This paper reviews the data, provides recommendations for improving PFC emissions predictability, and suggests possible means for reducing these emissions.