Technologies paving the way to carbon neutral stainless steel production

Many steelmakers have set carbon neutral goals over the 2030-2050 timeframe. Naturally near-term approaches are focused on minor alterations and improvements parallel to mapping out longer term options. However, any technology change today should be ready for future use of hydrogen. Increase of the energy-efficiency immediately reduces the carbon footprint, and for most stainless steel producers there are four processes to address: the electric arc furnace (EAF); the AOD converter; ladle preheating; reheating and annealing. This paper discusses how this can take place and how use of hydrogen is considered. CoJet was introduced by Linde 25 years ago, and it has revolutionized EAF operation. Today more than 170 EAFs are using CoJet, yet rather few among stainless steel makers. The energy-efficiency of the AOD can be approved by using good performing control systems. An example of the that is AOD-IRS, which is successfully in operation at more than 100 AOD converters. To achieve preheating and reheating with a low carbon footprint - and ultimately bring it to zero - a first step is to increase the energy-efficiency. Flameless Oxyfuel has a demonstrated ability to reduce the fossil fuel consumption in ladle preheating and reheat furnaces by typically 20% to -50%. With more than 200 installations in ladle preheating and 180 in reheating and annealing, it is a wellestablished solution, which already has led to considerable decarbonization, and installations using hydrogen as fuel will be commissioned shortly.