The production of hydrogen through microwave-initiated catalytic dehydrogenation of model hydrocarbon compounds on Fe/AC catalyst without significant CO₂ emissions

Abstract The utilization of hydrogen as a fuel source through the microwave-initiated catalytic deep-dehydrogenation (MICDD) of Saudi Arabian light crude oil (LCO) using Fe metal supported on activated carbon has been proposed for this study to achieve the current target of limiting global warming to 1.5 °C above pre-industrial levels. Should renewable technologies, for example, wind and solar, be not able to decarbonise the energy industry sufficiently in the near future, other approaches are needed to generate energy without the emission of massive amounts of aerial carbon (CO 2 ). The composition of crude oil varies depending on its source; however, it is mainly composed of three families of hydrocarbons (paraffins, naphthenes, and aromatics). The aim of this work is to gain an understanding into the contribution of a single hydrocarbon model compound and combinations of these model compounds in proportions close to their real proportions in the LCO preparing a “synthetic crude oil”. In this work, hexadecane, cyclohexane, and benzene, toluene, and xylene (BTX) were selected to closely represent paraffins, naphthenes, and aromatics respectively. It was found that this as a facile route to produce both high concentrations of hydrogen from hexadecane (~90 vol. selectivity) and significant amounts of carbon multiwalled nanotubes over 30 wt. % Fe/AC catalyst at 1000 W input power. The results highlighted the effect of the composition of crude oils on the efficiency of H 2 production and showed that paraffinic feedstock was relatively better for producing H 2 among other hydrocarbons, and the presence of cyclic hydrocarbons, particularly aromatics, may inhibit H 2 production. Importantly, this process creates solid carbon as a by-product of the process instead of CO 2 and therefore does not contribute to climate change. The approach also has the potential to synthesise other high-value hydrocarbons as by-products.