Comparative techno-economic and life cycle assessment of fixed and fluidized bed reactors for dry reforming toward sustainable carbon monoxide and hydrogen production

Carbon monoxide is a key platform chemical for fuels and chemical synthesis, while hydrogen serves as an energy carrier and reducing agent. However, their conventional production routes are energy-intensive and environmentally unsustainable. The dry reforming of methane (DRM) is a promising alternative that utilizes methane and carbon dioxide to produce low-carbon CO, with hydrogen as a valuable co-product. Although fixed-bed and fluidized-bed DRM reactors have been widely studied at the laboratory scale, their commercial viability under consistent process boundaries remains insufficiently explored. In this study, fixed-bed and fluidized-bed DRM reactors were systematically compared using experiment-calibrated process simulations, followed by techno-economic analysis and life cycle assessment for a 500 tons of CO per day process. Under the baseline condition of 850°C and a CO 2 /CH 4 feed ratio of 2, the fixed-bed process achieved a levelized cost of 366 USD/ton-CO, approximately 39% below the market price, with net CO₂ emissions of 0.283 kg-CO 2 /kg-CO. The fluidized-bed process exhibited a higher cost of 531 USD/ton-CO while achieving slightly lower net emissions of 0.278 kg-CO 2 /kg-CO. Sensitivity analysis indicated maximum cost variations of 30.1% and 22.0% for the fixed-bed and fluidized-bed configurations, respectively, primarily driven by the market value of by-product H 2 . Overall, the fixed-bed DRM process is favored under mild carbon regulation and capital-constrained conditions, whereas the fluidized-bed configuration becomes more competitive for continuous high-temperature operation, coke-resilient performance, and stringent carbon policies. These results provide quantitative guidance for selecting DRM reactors in diverse industrial and policy scenarios.