(60q) Multiscale Modeling of Dry Reforming of Methane to Study the Effect of Catalyst Morphology

Dry reforming of methane is a promising technology for converting two greenhouse gases, methane and carbon dioxide, into syngas, which is a mixture of hydrogen and carbon monoxide that can be utilized to produce chemicals through the Fischer−Tropsch process. However, dry reforming of methane has significant challenges for commercialization, one of which is the formation of carbon deposits known as coke. Cokes generated on the catalyst surface cause catalyst deactivation.

Numerous researchers are focused on developing catalysts for dry reforming of methane. Although novel metal catalysts are less prone to coking compared to transition metals, transition metals are preferred due to their low cost. Among the transition metal, Ni-based catalysts are adopted for high activity. The size of the nickel particles and metal-support interaction have strong effects on the methane conversion and carbon deposition. Previous studies using different morphologies of aluminum supports such as nanosheets, nanofibers, and particles revealed that the catalyst's activity and stability were strongly influenced by the catalyst morphology in the dry reforming reaction. Therefore, the catalyst morphology is an important factor to consider in the design of catalysts for the dry reforming of methane. However, the relationship between the structure-property of catalysts and their performance is still not fully understood. Furthermore, the filamentous carbon deposition resulting from the coking can effectively change the morphology of the catalyst, yet there has been no research conducted on the effects of carbon fibers on the reactions. In this regard, a multi-scale modeling study to understand the coking mechanism can be beneficial for designing coke-resistant catalysts. In this research, the kinetic Monte Carlo simulation is conducted for various catalyst morphologies and filamentous carbon accumulation is observation to figure the relationship between structures and performance. For commercialization of dry reforming of methane, besides coke generation, other important issues are outstanding such as increasing syngas yield and identifying the H₂/CO ratios. In order to study them comprehensively, the multi-scale modeling of dry reforming of methane reactor is developed by integrating a macroscopic reactor model with the kinetic Monte Carlo simulation. Through this, we expect to provide some guidance for developing catalyst and reactor design.