Air Emissions

      Conventional production of pig iron and steel generates air pollutants such as carbon dioxide (CO2) as well as sulfur dioxide (SO2) and nitrogen oxides (NOX) simply for reasons related to processes and raw materials.

      voestalpine fully complies with the relevant statutory thresholds. These parameters are verified and the annual loads determined by means of continuous measurements, periodic tests, and material flow analyses. State-of-the-art scrubbing facilities (i.e., end-of-pipe measures) are utilized in addition to continual process optimization (i.e., process integrated (PI) measures) to minimize remaining emissions.

      Over the past several decades, the voestalpine Group substantially lowered the level of its emissions thanks to extensive environmental measures and innovations in process technology. Given existent steel production technologies, the residual air emissions are the minimum achievable.

      Greenhouse gas emissions

      The direct greenhouse gas emissions (Scope 1) of the voestalpine Group’s roughly 120 production facilities rose in calendar year 2021 by 16.2% to 14.5 million tons of CO2 equivalents, after declining the previous year on account of the COVID-19 crisis. In Austria, the Group’s plants in Linz and Donawitz that use the blast furnace route to produce crude steel account, respectively, for 9.6 million tons and 3.1 million tons thereof.

      Over and above carbon dioxide, the emissions data also include two other greenhouse gases, specifically, methane and nitrous oxide.

      In addition to the direct (Scope 1) emissions, the indirect greenhouse gas emissions (Scope 2 + Scope 3) were also compiled and analyzed in accordance with the EU’s environmental footprint (EF) 3.0 climate change methodology.

      Scope 1 emissions

      In millions of tons of CO2e

      Scope 1 emissions (barchart)
      * Scope 2 market based: 0.55 million tons CO2e
        Scope 2 facility based: 0.73 million tons of CO2e

      Direct and indirect greenhouse gas emissions 2021

      In millions of tons of CO2e

      Direct and indirect green house gas emissions (barchart)

      SO2 emissions

      The use of particular raw materials—especially coal and coke—introduces sulfur into the production process. Additional processing steps and the use of by-products such as coke oven gas (COG) and blast furnace gas (BFG) for thermal recycling generates sulfur dioxide (SO2).

      While the specific SO2 emissions in calendar year 2021 were 0.44 g/t of product and thus less than the previous year’s value of 0.46 kg, in absolute terms, SO2 emissions rose from 4.4 kt to 4.6 kt for production-related reasons.

      SO2 emissions


      SO2 emissions (barchart)

      Specific SO2 emissions

      kg/t product

      Specific SO2 emissions (barchart)

      NOX emissions

      Nitrogen oxides are generated through the operation of industrial furnaces and thermal recycling of by-product gases.

      Due to the renewed increase in production, voestalpine’s absolute NOX emissions climbed in calendar year 2021 from 5.0 kt to 5.9 kt. The specific NOX emissions per ton of product were 0.55 kg (previous year: 0.53 kg).

      NOx emissions


      NOX emissions (barchart)

      Specific NOx emissions

      kg/t product

      Specific NOX emissions (barchart)

      Captured dust emissions

      Dust-laden exhaust air and exhaust gases that occur during production are captured and channeled to dedusting systems using state-of-the-art processes and equipment.

      In calendar year 2021, the captured dust emissions per ton of product remained low both in absolute terms (0.35 kt) and specifically (33 g).

      Captured dust emissions


      Captured dust emissions (barchart)

      Specific captured dust emissions

      g/t of product

      Specific captured dust emissions (barchart)

      Organic air pollutants

      Organic air pollutants (i.e., volatile organic compounds – VOC) are generated primarily during the thermal process stages of crude steel production as well as during the associated combustion processes.

      In recent years, voestalpine commissioned several technically sophisticated pieces of equipment to cut VOC emissions. This made it possible to achieve a substantial decline in the emission of organic air pollutants. In calendar year 2021, VOC emissions per ton of product were 0.16 kt (2020: 0.15 kt) absolutely and 15 g (2020: 16 g) specifically.

      VOC emissions


      VOC emissions (barchart)

      Specific VOC emissions

      g/t of product

      Specific VOC emissions (barchart)