Tuesday, August 02, 2016

Changes in Steel Production Reduce Energy Intensity

Energy Intensity of U.S. Steel Production (Credit: U.S. Energy Information Administration, Annual Energy Outlook 2016) Click to Enlarge.
The manufacture of steel and related products is an energy-intensive process.  In 2015, the steel industry accounted for 1.5% of all industrial shipments but 6.1% of industrial delivered energy consumption.  In EIA’s Annual Energy Outlook 2016 (AEO2016) Reference case, energy use in the steel industry increases by 11% over 2015–40.  Over the same period, the steel industry’s energy intensity falls by 27%, compared with an 18% reduction in total industrial energy intensity.  Several alternative cases examine drivers for further energy intensity reductions in the steel industry.

Much of the change in energy intensity is attributed to the shift in steel production from primary to secondary (recycled) production.  Primary production of steel typically uses a blast furnace to produce molten iron from iron ore, coking coal, and limestone.  The molten iron is then converted into steel by a basic oxygen furnace.  Secondary production of steel typically uses an electric arc furnace, with scrap providing the main input.  In an electric arc furnace, scrap is melted using electricity.  Natural gas can also supplement the melting process.

Overall energy intensity of an electric arc furnace is significantly lower than the energy intensity of a basic oxygen furnace.  The shift from using the basic oxygen furnace to the electric arc furnace since the early 1990s has contributed to the substantial reduction in energy intensity in the U.S. steel industry.  According to calculations based on the Manufacturing Energy Consumption Survey and the World Steel Yearbook, from 1991 to 2010, the share of U.S. steel production using electric arc furnaces increased from 38% to 61%, while the energy intensity of crude steel production decreased by 37%.  In the Reference case, the electric arc furnace share of crude steel production increases to 69% by 2040, further decreasing energy intensity.

Read more at Changes in Steel Production Reduce Energy Intensity

No comments:

Post a Comment