Flexible hydrogen heating technologies, with low environmental impact

Abstract

Several roadmaps worldwide identify the decarbonization as one of the main pathways to transform the steel industry into a climate-neutral sector by 2050. New technologies and processes based on the massive use of renewable electricity, green hydrogen, and their combination, will play a fundamental role in this transformation. Aside this decarbonization pathway, the steel sector suffers from a strong inertia due to its characteristics of being very capital intensive, operating in a highly competitive global market and being characterized by an investment cycle between 20 and 30 years. In such scenario, the Tenova “Hydrogen Ready” combustion technology (which identifies a burner family able to work with any natural gas/hydrogen mixture up to 100% H2 without hardware modifications) represents a solution able to support the steelmakers through the current energy transition scenario and, at the same time, to ensure their investments for the future. This paper continues a previous work on the Tenova “SmartBurner” technology and shows the application of the “Hydrogen Ready” concept to three additional burner families, covering a wider range of downstream processes: Tenova TRKSX (flameless self-recuperative burner for heat treatment furnaces), Tenova TRGX (regenerative flameless burner for reheating furnaces), and the Tenova THSQ burners (flameless combustion system for batch annealing furnaces, heat treatment furnaces and other special heat treatment application). All these burners show NOx emissions well below the next envisioned limits (80 mg/Nm3 at 5% of O2 with furnace at 1250 °C) with all the NG/H2 mixtures, as well as with 100% H2. These results confirm the viability of the “Hydrogen Ready” approach, and the effectiveness of the flameless technology in controlling the NOx formation. The first industrial applications of these concepts are also presented.