PFCs from the Chinese aluminium sector—Challenges in emissions accounting and further characteristics

Abstract

PFCs from high voltage anode effects (HV-AE ≥8 V) in aluminium smelters are currently accounted for by 2006 IPCC methodologies. Industry accounting of global PFCs is done by the IAI via anode effect (AE) surveys, however reporting from Chinese facilities remains limited, contributing to a 55% non-participation rate in 2015. A Chinese AE survey was conducted to help provide further data. However responses (supported by data from a case study smelter) highlighted that AE frequency (AEF) and duration (AED) statistics in China often do not include all detected AEs (only longer duration AEs e.g. ≥60 s) which is inconsistent with IPCC Tier 2 PFC accounting methodologies. The paper also presents PFC measurement data (2011–12) from 10 potlines in China, showing that unaccounted emissions from low voltage anode effects (LV-AE <8 V) can also be significant for low-amperage (235–240 kA) cells and that total PFC emissions were negatively correlated with current efficiency.