Ref. Ares(2020)3608028 - 08/07/2020
Ref. Ares(2021)4414341 - 07/07/2021
Annex to amendment 1 on industrial gases: technical details on the use of
oxygen in the steel industry
Using pure oxygen instead of air for the combustion of fuels helps to improve the energy efficiency
of furnaces as energy for heating the nitrogen ballast is no more needed, thus the fuel
consumption and direct CO2 emissions are reduced. As nitrogen is no more needed, using pure
oxygen for combustion also leads to the reduction of volume of combusted gas/arising gas (gas
arising from the combustion), which means that less gas volume needs to be transported. This
translates to reduction of electricity consumption of the fans. This technological improvement is
used in the steel industry. In this regard, oxygen is used in furnaces of the integrated steel route
to reduce the consumption of self-generated gases and natural gas in the furnaces for iron and
steel production and in the heating and reheating furnaces of the downstream steel processing.
Pure oxygen is also being widely used in the secondary steel production route. Pure oxygen instead
of air is used in so called oxy-fuel burners in Electric Arc Furnaces to improve energy and resource
efficiency through substitution of electricity (see figure 2) and chemical energy (from combustion
of natural gas); hence, compensation for both electricity and oxygen consumption is needed to
ensure the level playing field. Oxy-fuel burners use pure oxygen instead of air for burning the fuel
gas. They increase the productivity of the furnace (output) by increasing the speed of the melt and
reducing the consumption of electricity and electrode material, which reduces GHG emissions.
Electricity savings may range from 2.5 to 5.0 kWh/ m3 of oxygen injected. The use of oxy-fuel
burners has several other beneficial effects: it increases heat transfer, reduces heat losses, reduces
electrode consumption, and reduces tap-to-tap time. Moreover, the injection of oxygen helps to
remove different elements from the steel bath, like phosphorus, silicon and carbon.
Figure 1: Fuel savings and arising gas decrease during natural gas combustion from air/fuel to
oxygen/fuel combustion
Source: Energy use in the iron and steel industry, EUROFER
Figure 2: Electricity savings as a function of oxygen usage in Electric Arc Furnace
Sources: CO2 abatement in the iron and steel industry; Anne Carpenter, 2012; Oxyfuel combustion in
the steel industry: energy efficiency and decrease of CO2 emissions; Joachim von Schéele, The Linde
Group Germany