Brazilian Steel Production introduces Carbon Dioxide Emissions

12 February 2015

In a study published in Nature Climate Change, scientists show that the carbon dioxide emissions from Brazil’s steel production doubled in the 2000-2007 period, despite a decrease in the use of coal.

According to the researchers, Brazil used native charcoal, i.e. charcoal produced from native forests, to fuel the steel-production industry… which led to deforestation and, consequently, to higher carbon dioxide emissions.

Steel Production

Steel is one of the most-produced materials, with applications in many different fields, including construction and aerospace.

Steels are alloys of iron and carbon; depending on the applications, however, carbon content can vary and additional elements can be present in the alloy.

Manufacturers generally produce steel from iron ores, such as iron oxides (i.e. Fe2O3). To convert the oxide into metal, they must employ a reducing agent in the process. This is normally carbon (C) in the form of coal.

Carbon Dioxide Emissions

Due to the use of carbon, steel production results in the emission of a remarkable quantity of carbon dioxide (CO2). Literature data report that about 7% of the world anthropogenic (man-made) CO2 emissions are linked to steel manufacture.

These data cause concern, as CO2 is a greenhouse gas; according to some people, the increased CO2 atmospheric concentration is a cause of global warming. Moreover, the higher CO2 level is causing an increase in the acidity of the oceans.

Alternative Solutions

Because of this, alternative strategies have been tested and implemented, to try to reduce the CO2 emissions associated with steel production.

One solution is to replace coal of fossil origin with coal of biomass origin, i.e. obtained from the wood of trees grown on non-forest land (plantation charcoal).

In principle, the use of plantation charcoal leads to a carbon neutral process, since the CO2 generated in the steel production can be offset by the plantation and the growth of the trees. This kind of process is recognized as a Clean Development Mechanism (CDM), according to the Kyoto Protocol agreement.