This research systematically investigated the catalytic pyrolysis of Arab Heavy (AH) and Arab Light (AL) crude oils using NiO supported on Al2O3 or ZSM-5 in a microwave-assisted reactor, with particular emphasis on hydrogen (H2) generation and value-added chemicals. To understand how both the catalyst and feedstock affect reaction products, gas and liquid products as well as catalyst activity were carefully examined. The production of H2 and olefins was significantly enhanced by the NiO/Al2O3 catalyst, especially when using AL crude. This is most likely due to favorable metal-support interactions that increase the dehydrogenation activity. However, when paired with lighter feedstock, NiO/ZSM-5 greatly increased paraffin production and encouraged light alkane synthesis in both phases. GC-MS and FTIR spectroscopy confirmed that NiO/Al2O3 produced liquid products richer in aromatics while also containing a significant fraction of paraffins. Remarkably, the AL over NiO/Al2O3 combination showed very little liquid recovery, indicating that gas generation was higher in these reaction conditions. These results showed how H2 selectivity and hydrocarbon routes in NiO/ZSM-5 and NiO/Al2O3 are controlled by various microwave-catalyst interactions. This work further highlights the importance of matching catalyst properties with feedstock type to control product selectivity, with NiO/Al2O3 showing particular promise for H2-focused applications.
Hassan et al. (Mon,) studied this question.