Environmental impact of steel on air quality, deteriorating atmospheric conditions

October 29, 2024
Manufacture of rolled steel products - Kunak

Table of contents

The world is hungry for steel, as evidenced by the high global demand for this vital material and its contribution to economic and social development. The Neom project, currently being developed by Saudi Arabia with a vision towards 2030 to diversify the country’s economy beyond oil, already consumes a fifth of the steel produced worldwide.

World Steel in Figures 2024 infographic

The steel industry plays an essential role in modern economies. Steel is a malleable and highly versatile material in the industrial world, with properties that facilitate the manufacture of numerous essential goods. It has significantly contributed to major social progress in sectors such as construction and infrastructure development, and in the production of goods for priority sectors, including the automotive industry, tools, and heavy machinery, among others.

The processing of iron to obtain steel dates back to ancient times, as evidenced by classical cultures such as the Hittite and Greek. However, it was not until the late 14th century that its large-scale exploitation began due to an increase in the size of iron ore smelting furnaces. Since then, the steel industry has developed a wide range of uses, fostering notable technological advances that have promoted progress and the well-being of humanity in sectors such as transport, energy, and telecommunications.

Cómo se distribuye el mercado mundial del acero - WorldSteel - Kunak

How the global steel market is distributed – WorldSteel

In addition to driving innovation and industrial development, steel offers the significant advantage of being a fully recyclable material. This promotes the circular economy by reducing the demand of raw materials while, at the same time, minimising the generation of waste from impurities.

Producción mundial de acero 2023 - WorldSteel - Kunak

World steel production 2023 – EUROFER (European Steel Association)

The steel industry and its environmental impact

Although the steel industry is one of the fundamental productive sectors due to its intensive use as the main material in the development of infrastructures and industrial products worldwide, steel manufacturing faces a significant environmental challenge. This is because it considerably impacts the environment by releasing pollutants during its production processes.

“The steel industry is one of the main contributors to anthropogenic CO2 emissions worldwide and therefore a significant driver of climate change.” European Parliament.

Metal extraction, high-temperature furnaces that consume large amounts of energy for their operation and the emissions generated during steelmaking processes are the main sources of pollution associated with the steel production.

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The nearly 10% increase in CO2 emissions into the atmosphere can be attributed to the steel industry. With 1.91 tonnes of CO2 emitted into the atmosphere for every tonne of steel produced, fossil fuel-driven steel production emerges as one of the principal sources of carbon emissions worldwide, directly impacting th atmosphere and degrading air quality.

According to the European Steel Association (EUROFER) report, in 2022, global steel production reached 1.88 billion tonnes, resulting in the emission of 3.6 billion tonnes of CO2 into the atmosphere.

The industrial processes involved in steel production primarily release greenhouse gases, particulate matterAtmospheric particulate matter are microscopic elements suspended in the air, consisting of solid and liquid substances. They have a wide range of sizes an...
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, and volatile organic compounds into the air
. These pollutants cause serious harm to human health and the environment; likewise, their presence and reactions in the atmosphere contribute to climate change.

Air quality in the steel industry

The areas closest to the steel plants are the most affected by the pollution generated during steel manufacturing. The emission of fine particulate matter (PM2.5 and PM10), nitrogen oxides (NOx), sulphur dioxideSulphur dioxide (SO2) is a colourless gas with a pungent odour that causes an irritating sensation similar to shortness of breath. Its origin is anthropoge...
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(SO2) and greenhouse gases such as carbon dioxideCarbon dioxide (CO2) is a gas that occurs naturally in the atmosphere and plays a crucial role in the life processes of the planet. This gas, also known as...
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(CO2) are the main pollutants responsible for altering air quality. Reducing these emissions is essential for mitigating climate change and improving public health.

Steel coils in stock - WorldSteel - Kunak

Steel coils in storage – WorldSteel

Main pollutants in steel production

The pollutants generated during steel production originate from various process stages, including raw material extraction, smelting, and finishing. The main pollutants in the steel industry include:

Particulate emissions

Suspended particulate matter (PM10 and PM2.5) is primarily released during machining and smelting processes. It negatively affects air quality and public health by exacerbating respiratory conditions. Similarly, the presence of these particulates in the air contributes to smogSmog, beyond that dense fog Smog is a mixture of air pollutantsAir pollution is one of the greatest environmental challenges of our time. The air we breathe contains various harmful substances of a chemical, physical o...
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that accumulate in the atmosphere, especially in urban areas. This phenomenon is character...
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formation. In addition, they can reach areas far from the steel production sites, as suspended particles are easily carried by wind and atmospheric circulation.

Greenhouse gases (GHG)

Carbon dioxide (CO2) is the main gas released into the atmosphere during steel production. Steelmaking is one of the most carbon-intensive industrial activities due to burning fossil fuels, such as coal and natural gas, to reach the high temperatures required by smelting furnaces of the steel industry. Other gases, such as methaneMethane, known chemically as CH₄, is a gas that is harmful to the atmosphere and to living beings because it has a high heat-trapping capacity. For this ...
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(CH4),
are also produced, which is even more harmful as its atmospheric impact and contribution to global warming are 28 times greater than CO2. Carbon monoxide (CO) is also produced during the incomplete combustion of fuels, along with sulphur dioxide (SO2) and nitrous oxide (N2O).

Volatile organic compounds (VOCs)

VOCs are emitted during steel processing, specifically in annealing and heat treatment, and their presence can contribute to the formation of tropospheric ozoneTropospheric ozone (O3) or ground-level ozone is a gas found in the lowest layer of the Earth's atmosphere, the troposphere, which extends up to 10 kilomet...
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. This exacerbates air pollution and contributes to photochemical smog, which harms human health, particularly in large urban areas and negatively impacts ecosystems.

Fundición de acero - WorldSteel - Kunak

Steel casting – WorldSteel

Impact of steel on health and the environment

Exposure to pollutants emitted by the steel industry has serious consequences for human health and the environment. The most noticeable effects include:

Respiratory problems

The pollutants released into the atmosphere during steel production cause health conditions such as asthma, chronic bronchitis, and obstructive pulmonary diseases. In addition, using a carbon-rich fuel such as coke results in the release of naphthalene, a product possibly carcinogenic to humans. Steel production also generates heavy metals, such as lead and cadmium, which have been shown to cause long-term health problems and the environment damage.

Impacts on climate change

Steel is a highly sustainable material because of its strength, which gives it a long lifespan, and its ease of recycling. However, its production is highly polluting due to the increase in greenhouse gases resulting from using fossil fuels and coke (coal made by heating it to high temperatures), an essential raw material for its manufacture.These factors make the industrial activity associated with steel one of the main drivers of climate change.

Acidification of soil and water bodies

These are environmental problems caused by SO2 and NOx emissions from steel production that lead to acid rain that affects both soil composition, water bodies, and vegetation. Finally, these atmospheric emissionsAtmospheric emissions are pollutants emitted into the air, mainly as a result of human activities such as industry, transport by combustion vehicles and en...
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impact natural diversity, causing widespread effects on ecosystems.

Almacenaje de acero para su transporte en barco - WorldSteel - Kunak

Storage of steel for transport by ship – WorldSteel

How to reduce the environmental impact of steel?

Implementing emission control technologies and optimising the industrial process involved in steel manufacturing are essential to mitigating the environmental impact of steel manufacturing and achieving the target of net-zero emissions by 2050.

The industry of decarbonisation required to reach this goal means that the annual CO2 emissions from steel manufacturing should be reduced by an average of 4% by 2030. However, predictions suggest that

Through innovation, the implementation of low-carbon technologies and improvements in efficiency in the use of resources, the steel industry can reduce its energy consumption and pollutant emissions.

Below are some technological solutions and strategies that can help reduce emissions.

Particle capture and filtration systems

One of the most effective technologies for reducing particulate emissions is installing advanced filtration systems, such as bag filters and electrostatic precipitators. These technologies allow the capture of suspended particles before they are released into the environment.

Acciones para mitigar emisiones CO2 - WorldSteel - Kunak

Actions to mitigate CO2 emissions- WorldSteel

Gas and vapour treatments

Gas treatment systems, such as gas reduction reactors and thermal incinerators, can significantly reduce emissions of polluting gases such as GHGs and volatile organic compounds.

New energy sources

In addition to making steel production processes more energy efficient, efforts are being made to use the latest energy sources for steel manufacturing, moving away from fossil fuels. Renewable energy and green hydrogen do not change the structure of steel, but the energy source used, hydrogen, is the most abundant chemical element. This hydrogen, if obtained through renewable energy such as solar, wind, or hydroelectric power, is known as green hydrogen. This hydrogen is used to produce green steel, which is manufactured in a much more environmentally friendly way, with lower emissions to the atmosphere.

Producción hidrógeno verde - WorldSteel - Kunak

Green hydrogen production – WorldSteel

Recycling

The steel industry uses a high percentage (85%) of recyclable material in the form of steel scrap. Although the use of scrap metal in blast furnaces is 30%, in steel plants using electric arc furnaces, it is possible to use 100% recycled raw material.

Reusing materials results in high energy savings, requiring only one-eighth of the energy required to produce steel from iron ore, and, at the same time, there is a significant reduction in CO2 emissions by preventing the emission of 1.5 tonnes of CO2 for every tonne of steel produced.

Monitoring and Measurement of air quality

The implementation of accurate and continuous air quality monitoringControlling air quality is an essential task in order to enjoy optimal environmental conditions for healthy human development and to keep the environment i...
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systems enables real-time detection and control of emissions in the steel industry. Advanced sensors facilitate the measurement of the concentrations of critical pollutants such as SO2, NOx, and particulate matter. Having reliable and accurate measurements is crucial to ensure a safe working environment and environmental control per current environmental regulations.

In conclusion, despite the significant challenges facing the steel industry, there are opportunities to make it a more sustainable industrial activity. By relying on technology and improving key processes, the efficiency of resource use and energy demand can be improved. Achieving this requires a common framework of interest involving producers, partners, public administrators, and researchers aligned with priority policies for advancing towards a decarbonised economy.

“If we want to limit global warming to between 1.5 and 2 degrees, we must take ambitious steps towards reducing carbon emissions to zero over the next 10 to 20 years. Meet this challenge will require us to reinvent almost every sector of our modern lives.” European Parliament.

Kunak’s solution for the steel industry

Kunak has developed air quality monitoring solutions specifically for the steel industry. Their systems enable precise measurement of pollution levels, providing real-time data so that companies can optimise their processes while reducing the environmental impact.

In an industry where steel production releases a wide range of pollutants into the air, from fine particulate matter to volatile organic compounds, effective solutions are crucial. Kunak employs advanced technology based on high-precision sensors calibrated to international standards, which detect particulates and pollutant gases. In this way, they identify sources of pollution and, with the data provided, facilitate informed and effective decision-making to mitigate emissions and their possible environmental impact, as well as implement preventive measures to improve the health of steelworkers.

Kunak AIR Pro

Accurate and reliable air quality monitoring

Kunak sensors improve production processes in steel plants by detecting diffuse emissions caused by anomalies. By rapidly identifying pollutant spikes, alerts are issued that allow operators to locate the source of the emission. This speeds up problem resolution, saving time and reducing costs associated with problems in steel production.

Kunak’s sustainable and efficient solutions in steel manufacturing facilities enable continuous air quality monitoring, ensuring compliance with the strictest environmental regulations and allowing plants to adapt quickly to changes in environmental regulations and market demands.

Kunak’s flexible solutions are designed to be scalable and adaptable to different types of industrial facilities. They allow systems to be customised according to the specific needs of each steel plant, considering factors such as the size of the facility, the type of industrial processes performed and the local climatic conditions.

Kunak also works closely with the steel industry to provide training and technical support, ensuring that staff can interpret data and apply best practices in air quality management. This tailored collaboration improves operational efficiency and strengthens companies’ commitment to environmental responsibility.

A strategic approach is essential for protecting the environment and public health while enhancing the public image of the steel industry, which is often seen as one of the largest industrial polluters.

Conclusions

The steel industry remains one of the most polluting industries in the world, having a significant impact on air quality and public health. Emissions of particulate matter, greenhouse gases, and volatile organic compounds contribute to climate change and exacerbate respiratory problems, especially among those living near industrial plants. However, with the implementation of advanced emission control technologies and air quality monitoring systems, it is possible to significantly reduce the environmental impact of this globally important industry.

Adopting technology-based solutions requires technical and economic feasibility for rapid implementation. Existing technological and innovative tools, such as those offered by Kunak, already provide an effective means to measure and control pollution. This helps steel companies comply with environmental regulations and improve the sustainability of their operations, supporting the global drive towards decarbonisation.

References