While there is a bunch of approaches to reducing the steel industry CO2 emissions – which shall be mentioned below – the choose of the technology depends upon various factors or various nature such for example as availability and therefore price of certain resources, applicable legislative and safety regulations, carbon prices etc.

It is also necessary to note that decrease of CO2 emissions in steel industry is to be considered as a complex outcome where not only direct CO2 emission is to be taken into account – for example CO2 emitted during the melting iron ore – but also emission having place during the manufacture of other inputs necessary for steel manufacturing process, for example electricity or hydrogen.

With regard to strategies being considered by European steel producers – which predominately use blast furnace (BF)/basic oxygen furnace (BOF) technology and to certain extent electric arc furnace (EAF) technology as their main manufacturing methods – the following are to be mentioned beforehand.

There is quite a number of strategies and technologies which are being implemented and tested by steel manufacturers nowadays, however not all of them may allow to reach carbon neutrality equilibrium. This article shall not examine in details those approaches which are not allowing to reach the said goal but focus only on those ones which may allow to do so.

Increase of use of EAF technology. The technology envisions use of steel scrap as main component to produce steel. While this technology may allow to meet carbon neutrality challenge to some maximum extent the feasibility of this technology shall depend upon availability of high-quality steel scrap and commercially viable green electricity. The question about electricity emerges due to the fact that we need to eliminate carbon emissions in all industries providing inputs for steel sector including power generating sector.

Optimization of EAF technology with direct reduce iron (DRI). When the high-quality steel scrap is scarce resource EAF may use DRI as a component to be used together with steel scrap to produce steel of required quality. However, DRI technology requires extensive use of natural gas resources so it might be feasible for regions with available vast supply of natural gas and affordable natural gas prices.

Implementing DRI and EAF technologies using hydrogen. Use of hydrogen in course of DRI manufacturing allows to reduce – if not to fully eliminate – CO2 emission and at the same time does not require use of substantial quantities of natural gas what eliminates the problem described in the above solution.

The major issue with this technology is a manufacturing of hydrogen. The hydrogen may be divided into two categories, the fist is so-called grey and green hydrogen. Grey hydrogen is produced by steam methane reforming which in its tern causes CO2 emission what is not allowing to reach all-in-all carbon neutrality. On the other hand, production of green hydrogen – what is being produced via electrolysis of water – is the only carbon free option which at the same time is energy intensive.

In case alternative renewable energy resources – what shall be meaning that such hydrogen production is entirely carbon-free – are used then the question of the price of electricity shall currently be high and seemingly not feasible.

However, with the lapse of time the situation is changing and economical feasibility of using green hydrogen in DRI production shall be pirouetting around price of green energy – which is declining and is expected to continue declining, electrolyzers efficiency – which is improving, and cost of CO2 emissions – that are increasing.