Structured ZSM-5 coated SiC foam catalysts for process intensification in catalytic cracking of n-hexane

Structured foam catalysts are technologies which address challenges in catalytic processes due to the mass and heat transfer limitations. In this work, ZSM-5 coated silicon carbide (SiC) foams were prepared by a dispersion-based method, resulting in a thin and uniform zeolite layer on the foam support (i.e. ZSM-5/SiC foam catalysts). A comparative study of catalytic cracking of n-hexane was studied over ZSM-5/SiC foam and ZSM-5 pellets catalysts at space velocities of 4–40 h−1, showing the improved n-hexane conversion, total selectivity to C2–C4 olefins and anti-deactivation performance, especially at the relatively high space velocities (>10 h−1), achieved by the ZSM-5/SiC foam catalysts. The light olefin yield obtained by the ZSM-5/SiC foam catalyst (with 45 ppi cell density) was almost five times higher than that by the conventional ZSM-5 pellets. A detailed analysis reveals that the specific surface area of SiC foams has the significant effect on the coating quality, and hence the catalytic performance in the cracking reaction.