Technical Viability of Different Power to Gas Integration Configurations in a BF-BOF Iron and Steel Plant

Emitting up to a 5% of all anthropogenic CO2, the iron and steel industry is one of the most energy-intensive industry. The control of CO2 emissions is becoming crucial in many countries and in order to fight against global warming, carbon capture will be mandatory in coming years. If carbon capture is integrated with power-to-gas, the iron and steel industry could benefit. This paper introduces a new concept proposal that integrates carbon capture using MDEA with a PEM electrolyser and a methanation plant (power-to-gas technology, producing synthetic natural gas). The CO2 is captured from the blast furnace gas, and the SNG is continuously injected into the BF as a reducing agent, recycling the CO2and closing a carbon loop, avoiding geological storage. The oxygen by-produced in the electrolyser allows to eliminate the air separation unit (ASU). By integrating this novel concept, a 9.4% CO2 emission reduction can be achieved, with an energy penalty of 16.2 MJ/kgCO2. Additionally, an economic study has been carried out, varying the electricity price and the CO2 allowances price through a sensitivity analysis