Understanding of Co-evolution of PFC Emissions in EGA Smelter with Opportunities and Challenges to Lower the Emissions

In addition to the conventional electrochemical reaction in Hall-Héroult electrolysis process where the alumina is reduced to liquid aluminum, the co-evolution of anthropogenic perfluorocarbon (PFC) gases, namely tetrafluoromethane CF₄ and hexafluoroethane C₂F₆, was occasionally detected during the electrolysis process. In Emirates Global Aluminium (EGA), along with the continuous amperage creep program, incremental increase in anode dimensions and associated reduction in cell anode-cathode distance (ACD) to satisfy cell energy requirements, the company has focused its efforts on improving the advanced cell control algorithm which has assisted EGA technologies to operate at a high current density while maintaining low PFC emissions. As part of a continuous performance enhancement program, EGA has initiated a program to understand the temporal and spatial changes in cell conditions that cause the co-evolution of PFC emissions. The work included studies to gain insights in major events where the co-evolution of PFC emissions was detected using state of art continuous individual anode current monitoring, along with continuous monitoring of PFC emissions in reduction cells.