Combined steam and dry reforming of methane in narrow channel reactors

The performance of methane reforming reactions in narrow channel reactors has been investigated. Two types of reactors (Diffusion Bonded Reactor and Demountable Reactor) were utilized and two forms of catalysts were prepared by the sol-gel method with different additives. The sol-gels were prepared to have desirable rheological properties for coating onto stainless steel substrates, which after calcining formed an adherent thin catalyst layer. Employing the catalyst as a thin layer (<50 μm) coated on the channel surface reduces mass and heat transfer restrictions compared with pellet catalysts and can improve the effectiveness factor. Carbon deposition is known to be rapid in the case of the CO₂ reforming alone. In this study, carbon deposition was reduced drastically when CO₂ reforming is carried out simultaneously with the steam reforming reaction in narrow channels coated by thin layers of catalyst (≤50 μm) prepared using the sol-gel method. It has been shown that the stability and coking resistance of Ni/Al₂O₃ catalyst are increased by the addition of Ba, Cr and La₂O₃ in combined steam reforming of methane with carbon dioxide reforming. This process is an attractive approach for improving catalyst stability and offers the possibility of obtaining H₂/CO ratio close to 2, which is suitable for Fischer-Tropsch and methanol synthesis.