Dual pathways for refinery off-gas processing: Comparative analysis of steam reforming and co-electrolysis

In an effort to bridge the gap between academic research and industrial application, this study investigates the integration potential of steam methane reforming and Co-electrolysis for the efficient conversion of refinery off-gases into high-purity syngas. Experimental work was conducted under conditions representative of industrial environments, using platinum- and nickel-based catalysts in steam reforming to assess methane conversion and H 2 /CO ratio at varying temperatures and gas hourly space velocities (GHSV). Co-electrolysis was evaluated in solid oxide electrolysis cells (SOECs) across a range of gas compositions (H 2 O/CO 2 /H 2 /CO), including pure CO 2 electrolysis as a strategy for pre-electrolysis hydrogen removal. Electrochemical performance was analyzed using impedance spectroscopy, distribution of relaxation times (DRT), and current–voltage characterization. Results confirm the superior stability and performance of the Pt catalyst under high-throughput conditions, while Ni-based systems were more sensitive to operational fluctuations. In the SOEC, increased H 2 O content accelerated reaction kinetics, whereas CO 2 concentration governed polarization resistance. To enable optimal SOEC operation, the addition of steam downstream of the reformer is proposed as a means of adjusting the reformate composition. The findings demonstrate that tuning reforming and electrolysis conditions in tandem offers a promising route for sustainable syngas production using renewable electricity. This work establishes a foundation for further development of integrated thermo-electrochemical systems tailored to industrial gas streams. • Pt catalyst ensures high CH 4 conversion even under high-throughput conditions. • Ni catalyst shows sensitivity to GHSV and underperforms at elevated flow rates. • Optimal SOEC performance achieved at 45:45:10 H 2 O/CO 2 /H 2 feed ratio. • H 2 addition improves kinetics; CO causes polarization and surface poisoning. • Reformate steam addition enables tailored electrolysis feed for system integration.