Impact analysis of energy efficiency measures in the electrolysis process in primary aluminium production

The Paris Agreement includes the goals of ‘holding the increase in the global average temperature to well below 2°C above pre-industrial
levels’ and ‘making finance flows consistent with a pathway towards low greenhouse gas emissions’. Industrial energy efficiency will play
an important role in meeting those goals as well as becoming a competitive advantage due to reduced costs for companies. The aluminium
industry is energy intensive and uses fossil fuels both for energy purposes and as reaction material. Additionally, the aluminium industry uses
significant amounts of electricity. The electrolysis process in the primary production of aluminium is the most energy- and carbon-intensive
process within the aluminium industry. The aim of this paper is to study the effects on primary energy use, greenhouse gas emissions and
costs when three energy efficiency measures are implemented in the electrolysis process. The effects on the primary energy use, greenhouse
gas emissions and costs are calculated by multiplying the savings in final energy use by a primary energy factor, emissions factor and price
of electricity, respectively. The results showed significant savings in primary energy demand, greenhouse gas emissions and cost from the
implementation of the three measures. These results only indicate the size of the potential savings and a site-specific investigation needs to
be conducted for each plant. This paper is a part of a research project conducted in close cooperation with the Swedish aluminium industry.