Exploring the flexibility and profitability of combined steam and CO2 reforming in off-to-Valuables (O2V) pathway

Steelwork residue gases, such as coke oven gas (COG), offer significant potential for upcycling into high-value products, providing a sustainable alternative to conventional methods that emit CO2. This study addresses the need for adaptable and efficient production by proposing a co-production process of hydrogen (H2) and carbon monoxide (CO) from COG using a combined steam and CO2 reforming (CSCR) technology. The process enables flexible adjustment of the H2/CO product ratio by balancing steam- and dry-reforming reactions, addressing the need for adaptable production based on market demands. By optimizing key variables such as feedstock, reaction conditions, and recycling, the process achieves dual objectives: maximizing profitability through dynamic product ratio adjustments and reducing CO2 emissions by recycling captured CO2 as a reactant. A comprehensive analysis was conducted, including thermodynamic equilibrium analysis using the Gibbs free energy, process intensification, techno-economic-environmental analysis, and optimization-based production planning. The results demonstrate high carbon and energy efficiency of 98.7 % and 89.2 %, respectively, with low emissions of 1.13 kgCO2eq/kgH2 produced and a minimum selling price (MSP) of 1.91 $/kg. The study revealed that the Off-to-Valuables (O2V) pathway is highly dependent on chemical market prices, and emphasizes the importance of optimized operational strategies to maximize profitability in dynamic market conditions.