Unlike in the integrated steelmaking process, the greenhouse gas emissions related to electric arc furnace steelmakers come mainly from the use of electricity. While this gives the opportunity to reduce emissions by buying renewable energy, emissions can increase when such energy is in short supply.
SBB 21 February Outokumpu’s direct carbon dioxide emissions were up 45.6% year-on-year in absolute terms in 2010, Steel Business Briefing understands from the company’s annual report. A large part of the increase resulted from a 29.3% increase in stainless steel production.
However, a restricted supply of nuclear and renewable energy was also responsible for pushing these emissions up, the company tells SBB. The proportion of renewable and nuclear energy used fell to around 69% in 2010 from around 80% in 2009. Low water levels in Finland reduced the supply of hydroelectricity in the country and Sweden’s nuclear capacity was not connected to the grid for much of 2010, it notes.
Improvements in energy efficiency helped to counteract this effect somewhat: energy consumption per tonne of steel produced was reduced by 3% since 2007.
A reduction in secondary emissions from transport also contributed to a 0.3% reduction in combined direct and indirect CO2 emissions per tonne of steel. The company aims to reduce the total emissions per tonne of steel by 20% by 2020, as previously reported.
The company also managed to nearly double the amount of recovered metals from waste products to 80,408 t. The proportion of recycled and recovered scrap used per tonne of steel produced was nevertheless down from 94.5% to 91.1%.