Due to both processes and raw materials, conventional production of pig iron and steel generates various emissions such as carbon dioxide (CO2), but also sulfur dioxide (SO2) and nitrogen oxides (NOx).
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 any remaining emissions.
Over the last few decades, the voestalpine Group substantially lowered 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 (GHG) emissions (Scope 1) of the voestalpine Group’s roughly 120 production facilities declined in calendar year 2022 from 14.5 million tons to 12.7 million tons of CO2 equivalents. This is due, for one, to the sale of voestalpine Texas LLC (which was a primary source of GHG emissions) and, for another, to the downturn in production.
Both the Linz plant (8.9 million tons) and the Donawitz plant (2.9 million tons) in Austria account for most of the Group’s direct GHG emissions because they produce crude steel via the blast furnace route.
In addition to the direct emissions (Scope 1), we also collected data on the indirect greenhouse gas emissions (Scope 2 and Scope 3) and analyzed the data using the “EF 3.0 Climate Change total” method. To determine indirect GHG emissions, voestalpine avails itself only of verified data sets and emissions factors from known sources (sphera GaBi TS®) and primary data from suppliers. Besides carbon dioxide, the direct and indirect emissions data also include the greenhouse gases methane and nitrous oxide.
The observation period used for greenhouse gas accounting is to be expanded in the future, as follows: All voestalpine Group companies that engage primarily in downstream materials processing and thus have a significant impact on the Scope 3 emissions will have to be taken into account as well. Initial analyses to this end were already carried out during the reporting period. Quantification and systematic analyses are planned for the next reporting period.
Development of Scope 1, 2, 3 emissions
In million tons of CO2e
Direct and indirect greenhouse gas emissions 2022
In million tons of CO2e
Scope 2 facility based: 0.65 million tons of CO2e
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 turn sulfur into sulfur dioxide.
The specific SO2 emissions in calendar year 2022 were 0.54 kg/t of product and thus exceeded the previous year’s metric of 0.44 kg. This increase arises from the change in the production volume owing to the elimination of voestalpine Texas LLC. In absolute terms, the SO2 emissions remained constant at 4.6 kt.
SO2 emissions
kt
Specific SO2 emissions
kg/t product
NOX emissions
Nitrogen oxides are generated through the operation of industrial furnaces and the thermal recycling of by-product gases.
In calendar year 2022, voestalpine’s absolute NOx emissions fell from 5.9 kt to 5.5 kt. The specific NOx emissions per ton of product were 0.64 kg (calendar year 2021: 0.55 kg).
NOx emissions
kt
Specific NOx emissions
kg/t product
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 absolute terms, captured dust emissions fell in calendar year 2022 to 0.28 kt. In specific terms, the value remained constant at 33 g per ton of product and hence low.
Captured dust emissions
kt
Specific captured dust emissions
g/t of product
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.
voestalpine commissioned several technically sophisticated pieces of equipment in recent years to cut VOC emissions. This made it possible to bring about a substantial decline in the emission of organic air pollutants. In calendar year 2022, absolute VOC emissions were 0.14 kt (2021: 0.16 kt), and specific emissions were 17 g (2021: 15 g) per ton of product.
VOC emissions
kt
Specific VOC emissions
g/t product
