An Investigation of the Catalytic Activity of Inconel and Stainless Steel Powders in Reforming Primary Syngas

Biomass is perhaps the only renewable resource on the planet capable of delivering molecules similar to those derived from petroleum, and one of the most developed technologies to achieve this is gasification. When it comes to biomass conversion into fuels and commodities, supercritical water gasification (SCWG) could offer promising solution for producing hydrogen-rich syngas. However, the presence of methane (CH 4 ) and carbon dioxide (CO 2 ) in the syngas could negatively impact downstream processes, particularly when carbon monoxide is also required. Hence, improving the quality of the syngas produced from biomass gasification is essential for promoting the sustainability of several industrial processes. In this context, understanding the principles of the dry reforming of methane (DRM) becomes essential for upgrading syngas with high CH 4 and CO 2 content, especially when the carbon monoxide content is low. In addition to the experimental conditions used in such process, it has been reported that the material composition of the reactor can impact on reforming performance. Hence, this work aims at comparing the catalytic efficacy of Inconel and stainless steel for reforming syngas derived from SCWG under standard DRM conditions. In this specific work, the metals were directly used as catalyst and results showed that when using Inconel powder, CH 4 conversion increased from 3.03% to 37.67% while CO 2 conversion went from 23.16% to 51.48% when compared to stainless steel. Elemental and structural analyses revealed that the Inconel’s superior performance might be due to its high nickel content and the formation of active oxide compounds, such as FeNiO, FeCrO 3 , Fe 3 O 4 , Cr 2 O 3 , and Cr 2 NiO 4 , during the reaction. In contrast, Fe 3 O 4 was the only oxide found in stainless steel post-reaction. Additionally, increasing the total gas feed flow rate was shown to reduce CH 4 and CO 2 conversions, supporting the known impact of residency time on catalytic efficiency.