SO2 emission control in the aluminium industry

Abstract

SO2 emissions from the aluminium industry are modest on a worldwide and national scale. Large modern smelters using high-sulphur petroleum coke in anodes and smaller smelters with topographical unfavourable locations may, however, be significant sources locally. This has lead environmental regulators to again review local legislation. Currently SO2 emission legislation is in force in Scandinavia and in some parts of the US. The ongoing review of SO2 emissions may lead to stricter legislation forcing smelters outside these areas to install SO2 control systems. The electrolysis represents approximately 80% of the released SO2 for prebake smelters and approximately 95% for Söderberg smelters. The paper is addressing current SO2 removal technologies applied within the aluminium industry with focus on investment and operational costs.