Sustainability assessment of combined steam and dry reforming versus tri-reforming of methane for syngas production

Synthesis gas (syngas) is a versatile intermediate in the production of valuable chemicals and fuel, such as methanol, dimethyl ether, ethylene, propylene, and the Fischer-Tropsch fuel. Combining steam reforming and dry reforming (SR+DR) routes can produce syngas with a suitable H-2:CO molar ratio (around 2:1) for Fischer-Tropsch synthesis. The newly proposed tri-reforming (TR) route at experimental scale was a capable alternative to produce syngas in a single reformer with potential benefits such as energy savings and waste flue gas utilization. In this paper, sustainability assessment of SR+DR and TR routes adopting quantifiable indices in economic, environmental, and safety dimensions at industrial scale is performed based on process simulation models. Results show that TR route outperforms SR+DR route in all 3 dimensions. Sensitivity analysis of natural gas price fluctuation does not alter the conclusion. A sustainable root cause analysis is also applied on the SR+DR which identifies root causes affecting its sustainability with the aid of visualization tools such as Pareto chart and fish bone diagram.