A study by researchers in China has identified a catalyst—NiMoW—for the hydrotreating of the diesel distillate fraction from Fushun shale oil under relative mild conditions to produce a product that can be directly used as a transportation fuel. Their study appeared online 8 July in the ACS journal Energy & Fuels.
Shale oil has high levels of nitrogen, sulfur, and unsaturated hydrocarbons, limiting its potential use as a substitute fuel, the authors noted.
In China, reserves of oil shales account for about 500,000 billion tons. It is distributed mainly in Fushun, Liaoning province, Huadian, Jilin province, and Maoming, Guangdong province... However, the shale oils produced from oil shales contain a considerable amount of heteroatomic compounds, especially unsaturated hydrocarbons, which may cause many troubles, such as, instability of fuel during its transportation or storage...Catalytic hydrotreating may be considered as the only convenient way to remove heteroatomic compounds from shale oil. However, many papers showed that severe process conditions were needed during catalytic hydrotreating of shale oils. The concentrations of heteroatomic compounds in shale oils could be reduced, but they were still too high to be used as a transportation fuel. Denitrogenation was more difficult than desulfurization for shale oils.
—Yu et al.
The team investigated catalytic hydrotreating of the diesel distillate from Fushun shale oil was investigated using three types of catalysts at different conditions. The degrees of sulfur removal were high for all of the three catalysts, even at moderate conditions, indicating that most of the sulfur species in this distillate were reactive, which can be easily converted during the catalytic hydroprocessing. Denitrogenation was much more difficult than desulfurization, even at severe conditions, the authors found.
The NiMoW catalyst was the most active for heteroatom removal of the three.
Under relative mild conditions, it was possible to produce very stable oil from the Fushun shale oil distillate. After hydrogenation, produced oil had low contents of sulfur (41 µg g-1), nitrogen (195 µg g-1), and alkene, reduced density, and increased cetane number. The hydrotreated product can be directly used as a domestic transportation fuel.
—Yu et al.
Hang Yu, Shuyuan Li and Guangzhou Jin (2010) Catalytic Hydrotreating of the Diesel Distillate from Fushun Shale Oil for the Production of Clean Fuel. Energy Fuels, Article ASAP doi: 10.1021/ef100531u