A theoretical analysis of hydrogen-natural gas blends in slab tundish heating systems for green steel revolution

Öz

The transformation of the iron and steel industry toward carbon neutrality is a global priority under Net Zero 2050 strategies and the European Green Deal. Recent investigations have emphasized that hydrogen–natural gas (H₂/NG) blending represents a technically feasible and near-term approach for the partial decarbonization of high-temperature steelmaking operations. This study theoretically investigates hydrogen-natural gas blending for tundish preheating in slab casting, with a focus on İSDEMİR, one of Türkiye’s largest steel producers. A fuel mixture containing 10% hydrogen and 90% natural gas by volume is evaluated in terms of energy equivalence, CO₂ emissions reduction, and economic feasibility. The analysis assumes continuous operation, negligible heat losses, and 100 % combustion efficiency to isolate the effects of hydrogen blending. The results indicate that a 10 % hydrogen substitution yields a 3.2 % reduction in CO₂ emissions compared with the pure natural gas process, which aligns with previous combustion studies reporting 3-5 % CO₂ mitigation for similar H₂ fractions. The required hydrogen is produced on site with solar photovoltaic (PV) powered polymer electrolyte membrane (PEM) electrolysis system, achieving a 6.2 year payback period, consistent with economic evaluations from the International Renewable Energy Agency and the IEA Hydrogen Review. Beyond its numerical outcomes, this study provides a strategic model for Türkiye’s Green Steel transition, aligning with national decarbonization goals and the EU Carbon Border Adjustment Mechanism (CBAM). Similar frameworks across Europe and the UK illustrate the compatibility of existing natural gas infrastructure with blended fuels. The İSDEMİR case exemplifies how conventional gas systems can be progressively adapted for hydrogen integration, offering a replicable framework for other steel plants in developing economies. Additionally, the safety aspects of the H₂/NG mixture, such as flame stability, flashback risk, and potential impacts on burner components and refractory materials, are highlighted as subjects for future investigation to support practical application.

Anahtar Kelimeler

• Green steel
• Hydrogen blending
• Tundish preheating
• İSDEMİR
• Decarbonization
• Net zero by 2050.

Kaynakça

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