IMPROVED SELECTIVITY EFFECT OF COBALT, NICKEL CO-METAL IMPREGNATION WITH ZINC ON ZSM-5 FOR AROMATIZATION OF PROPANE
Research Development and innovation in chemical engineering
Conversion of light alkanes catalytically to aromatic compounds is an important research area of interest. This is because aromatic compound are the major feedstocks for petrochemical industries. Zn/ZSM-5 has been found to improve aromatic selectivity of HZSM-5 but unstable. Hence the need for stabilizing Zn with another metal. The interaction of Zn with Co and Ni on ZSM-5 shows a higher selectivity towards aromatics over 85%. This improved Zinc stability on ZSM-5 as compared to only Zinc with dwindling selectivity to 50% and HZSM-5 of 10% at ten hours TOS. Catalyst physicochemical properties were analysed with XRD, BET, N2-adsorption, FTIR, FTIR-Pyridine, SEM, and TEM. The XRD and FTIR characterization showed that the modified catalysts were still crystalline after metal impregnation. The products distribution also showed reduced light gases formation and formation of more aromatics. The synergistic interaction between Ni and Co with Zn metal improved the catalytic performance of Zn-Co/ZSM-5 and Zn-Ni/ZSM-5 catalysts by promoting and sustaining the dehydrogenation step and suppressing protolytic cracking step in the reaction series resulting in the recorded significant improvement in aromatic yield over the monometallic Zn/ZSM-5 catalyst.