Owing to its energy-intensive processes, conventional steelmaking still depends on fossil fuels. The emissions resulting from these processes as well as from chemico-physical reactions cannot be eliminated in full.
Yet voestalpine has been working for a long time to reduce process-related air pollutants to the technically possible minimum. This is accomplished by the continual optimization of technical processes (so-called “process integrated (PI) measures”). Remaining emissions are minimized by way of state-of-the-art scrubbing facilities (so-called “end-of-pipe measures”).
The major air pollutants that occur during the production of steel besides greenhouse gases (in particular CO2) are sulfur dioxide (SO2), nitrous oxide (NOx), and dust. voestalpine fully complies with the statutory limits regarding all of these emissions. These parameters are verified and their annual loads determined by means of continuous measurements, periodic analyses, and material flow analyses.
Comprehensive environmental measures have enabled the voestalpine Group over the past three decades to substantially lower emission levels to that which is technologically achievable at this time. As a result, the specific emissions per ton of crude steel have been reduced as follows: CO2 by 16%, SO2 by 82%, NOx by 65%, and dust by 96%.
Reduction in emissions
Per ton of crude steel since 1990
Greenhouse gas emissions
The direct greenhouse gas emissions of the voestalpine Group’s roughly 130 production facilities in 2019 amounted to 13.6 million tons, with Austria (specifically, the Group’s two crude steel production plants in Linz and Donawitz) accounting for the lion’s share thereof. The year-over-year increase (12.7 million tons) stems mainly from the fact that the largest individual blast furnace in Linz (Blast Furnace A) was temporarily shut down in 2018 for relining purposes.
voestalpine places great value on transparency and thus has participated in the Carbon Disclosure Project (CDP) among others since 2017. To this end, the greenhouse gas emissions have been tallied and externally verified in comprehensive fashion for all production facilities along the entire value chain in accordance with ISO 14064-3.
In 2019, voestalpine was given the CDP’s “A-” rating for its work to mitigate climate change as well as for the scope, quality, and transparency of the underlying corporate data and thus promoted to the CDP’s “leadership” category, the best of four. Most recently, voestalpine was awarded the CDP’s best possible supplier engagement rating—A, i.e., “global leadership”—which assesses climate change mitigation across the entire value chain.
Direct and indirect greenhouse gas emissions 2019
In millions of tons of CO2e
SO2 Emissions
The use of particular raw materials—e.g., coal and coke—introduces sulfur into the production process. During certain processing steps and when by-products (coke oven gas and blast furnace gas) are used for thermal recycling, sulfur is emitted in the form of sulfur dioxide (SO2).
While the specific SO2 emissions in the calendar year 2019 were 0.49 kg/t of product, the absolute SO2 emissions rose to 4.6 kt compared with the previous year during which they were lower due to the idling of the plant in connection with the complete overhaul of Blast Furnace A at the Linz site.
SO2 Emissions
kt
Specific SO2 Emissions
kg/t of product
NOx Emissions
In steel production, nitrogen oxides result from the operation of industrial furnaces and from thermal recycling of the by-product gases. The absolute NOx emissions of voestalpine in the calendar year 2019 were approximately 6.1 kt, and the specific NOx emissions were 0.64 t.
NOx Emissions
kt
Specific NOx Emissions
kg/t of product
Captured dust emissions
Dust-laden exhaust air and exhaust gases occurring during production are captured and channeled to dedusting systems using state-of-the-art measures and precautions. In the calendar year 2019, absolute dust emissions were lowered from 0.36 kt to 0.32 kt and specific dust emissions per ton of product from 37 g to 34 g.
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 primarily process related, resulting from the thermal process stages in crude steel production and/or in connection with the respective combustion processes. Following a significant reduction in the Group’s absolute VOC emissions in the calendar year 2018 thanks to investments in coal drying, VOC emissions were substantially lowered yet again in the calendar year 2019, from 0.24 kt to 0.17 kt in absolute terms and from 24 g to 18 g in specific terms (i.e., per ton of product).
VOC Emissions
kt
Specific voc emissions
g/t of product
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