Evaluation of time consistency when quantifying emissions of perfluorocarbons resulting from low voltage anode effects

Abstract

Low voltage anode effects (LVAE) have been recognized in aluminium smelters since mid 2000s. Such events are now known to generate perfluorocarbons (PFC) emissions over time and no methodology currently exists to adequately quantify such emissions for inclusion in greenhouse gas (GHG) inventories. A novel methodology has been proposed to estimate the annual LVAE emissions from the aluminium industry (Marks & Nunez) based on a set of existing measurement data from multiple in situ gas measurement campaigns. There is currently no estimate of the contribution of LVAE emissions using this methodology for past years. This paper investigates the potential effects of adopting this approach and applying it to historic emissions inventories of PFCs. Based on historical data supplied by a select set of aluminum smelters, the total respective PFC emissions resulting from high and low voltage anode effects were calculated, allowing evaluation of the potential impact of LVAE on the total amount of PFCs reported.