Hard, but promising: CO2-reduced steel

In principle, the equation is quite simple and has been known for a long time: More CO2 emissions mean more strain on the climate. Industry, too, is now aware that plans to minimize the consequences of climate change will not succeed without radical changes. Knowing this, innovative proposals for reducing CO2 emissions have already been developed and put into practice even in the steel industry, which is often ridiculed as the "old economy".

An example of this can be seen at thyssenkrupp Steel Europe AG. Under the umbrella brand bluemint® the company has been marketing new climate-friendly products since fall 2021 which are characterized by significantly reduced CO2 emissions during their manufacture. The reduction in CO2 emissions is achieved through solutions based on proven blast furnace technology.

One measure, for example, involves the increased use of metal scrap in the blast furnace and its recycling. Another approach involves the partial replacement of coking coal in the blast furnace with HBI (hot briquetted iron), which is obtained by reducing iron ore pellets with natural gas.

Another promising approach involves replacing coal in existing blast furnaces with "green hydrogen". Hydrogen, in other words, that has been produced using electricity from renewable sources. Instead of the undesirable CO2 that is produced as metallurgical gas when coal is conventionally used in blast furnaces, only water vapor is produced.

In the long term, the fundamental conversion of steel production is envisaged. This includes the gradual replacement of existing blast furnaces by gas-fired direct reduction (DR) plants with electric-powered melters. If green hydrogen is used as the gas, the DR plants can operate completely emission-free. The production of the first emission-free steel based on this technology was reported by the Swedish producer SSAB in the summer of 2021.

It will be exciting to see which solution approach will prevail in the long term: the use and improvement of existing (blast furnace) technology or the replacement of existing blast furnace technology with DR plants.

It is a fact that the carbon footprint of steel has become an important quality criterion. The race for innovations in the steel industry that lead to CO2 compensation and savings is in full swing. This is also evident from the fact that, as Cohausz & Florack has been observing for some time, the number of patent applications involving solutions for CO2 reduction and utilization is increasing. It is also striking that the resulting patents attract oppositions, strategically filed by other market players in the steel segment, probably with the aim of keeping avenues open for their own development.

So the steel industry is on the move - and hopefully our climate is on the right track.

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