Brazilian integrated long steel producer, Aço Verde do Brasil (Green Steel of Brazil) has achieved the pioneering milestone of carbon-neutral steel production, certified by Société Générale de Surveillance (SGS).
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The 600,000 mt/year mill, based in Brazil's northern Maranhão state, has relied on renewable power and invested in circular use of raw materials, along with its hot metal production based on eucalyptus charcoal, replacing traditional coking coal.
The company has 50,000 hectares of planted eucalyptus for sustainable charcoal and captive pig iron production.
In 2020, AVB reached negative 0.04 mt of CO2 per ton of steel. The world average emission is 1.88 tons, "therefore, AVB became the first carbon neutral steel producer," the company said.
Measuring the CO2 emissions from AVB operations, SGS verified the inventory of emissions of greenhouse gases from AVB between 2018 and 2019, following the GHG Protocol and methodologies internationally recognized by the World Steel Association. It was verified that no more than 0.10 and 0.06 mt of CO2 per ton of steel was released, respectively while the "worldsteel average" was at 1.81 and 1.83 in the same period.
For such a feat, AVB also adopted a series of actions and implemented several technologies such as renewable electricity from hydroelectric plants, reuse of its process gases (BOF and BF), to eliminate the use of fossil fuels, reuse of BF slag in its cement plant and reuse of BOF slag as BF and BOF raw materials.
Charcoal supply chain concerns
Despite some market observers concerns over CO2 emissions associated with the charcoal supply chain, AVB is fully confident of its processes and committed to replicate the route when the time to double its steel capacity comes.
Some other concerns exist on the production of charcoal in which CO2 emissions occur from the wood carbonization process itself, from the vehicles responsible for the harvest and during the transport of the raw material to the steel plant.
"When we consider the CO2 mass balance of the forest system and calculate the quantities removed/captured by photosynthesis of the forest, during its growth, we understood that the quantities removed/captured are immensely greater than the emissions. It is estimated that 1 hectare of eucalyptus forests can capture about 37 mt of CO2 per year," said Ricardo Carvalho, AVB CEO.
The concept is ratified by the GHG Protocol and by the United Nations Intergovernmental Panel on Climate Change (IPCC), which considers charcoal to be a carbon neutral raw material.
The Brazil steel institute Aco Brasil has had in effect since 2012 a Charcoal Sustainability Protocol that commits steel producers to maintaining a business relationship only with those companies that can provide documentary evidence of their legal compliance in all areas. Some steel producers in Brazil own and manage their own forests and manufacture their own charcoal.
As per the worldsteel perspective, the association said it is not prescriptive when it comes to the methods or technologies steel producers use to reduce their carbon emissions.
"Steel producers in different parts of the world operate in extremely different circumstances, so we are of the view that there is no single solution that will get the industry to where it needs to be; we will need to do whatever best suits local circumstances," it said.
AVB is also investing in the development of a patented charcoal carbonization furnace, set to enter the testing phase later this year.
"It is a pilot project but, if successful, it will be the technology used to produce 100% of AVB's charcoal needs," Ricardo said. With such a furnace, AVB will be able to further reduce CO2 emissions and the production costs of charcoal.
Besides becoming the first carbon-neutral steel mill, AVB is also seeking to become the first "zero waste mill" – meaning that 100% of solid waste will be reused.
AVB is part of the Ferroeste Group, which has been known for its pig iron production and has been diversifying its activities over the years to reforestation, cement and sugar cane ethanol production.