Sector-coupled co-optimization for hydrogen-heated steel plants considering production scheduling and electrolyzer flexibility in frequency reserve market

Hydrogen-based furnace heating via on-site electrolysis is a practical route to decarbonize secondary steelmaking, but requires tight coordination between production sequencing and electricity-driven hydrogen supply. This paper proposes a sector-coupled optimal scheduling strategy to co-optimize the steelmaking production schedule and the electrolyzer (EL) operation to minimize operating costs and reduce CO2 emissions. Firstly, a hybrid flow shop scheduling model for the entire steel production process coupled with the heating, hydrogen, and electricity consumption is established, which can optimize production sequences based on the electricity price. Secondly, an integrated scheduling strategy for hydrogen-based steel heating is proposed to jointly coordinate production operations, on-site hydrogen utilization, multi-energy and carbon flows, waste heat recovery, and frequency-reserve capacity provision (e.g., FCR-D), aiming at cost minimization and emission reduction. Finally, to address price and emission uncertainties, the problem is reformulated as a two-stage stochastic mixed-integer linear program (SMILP) and solved using progressive-hedging-based scenario decomposition to improve computational tractability. A case study based on Ovako’s hydrogen heating pilot demonstrates that the proposed coordination reduces operating costs by 31.84% and achieves lower emissions via reduced liquefied petroleum gas (LPG) use and improved energy utilization.