Upgrading of Light Cycle Oil to Premium Quality Diesel Blending Components via Selective Ring Opening Process; Part 1: Synthesis Strategies in the Search for Highly Accessible Microporous Zeolite Based Catalysts

摘要

LCO, which accounts for approximately 10-20% of FCC products, is a highly interesting blending stock to diesel pool because of the boiling point range similarity (LCO boiling point range = 221-343 °C). The major disadvantages of LCO, on the other hand, are primarily related to the high content and the structural complexity of mainly bulky multiring polynuclear aromatics, the so-called polynuclear aromatics. The current upgrading options (i.e. direct blending, catalytic saturation and hydrocracking) are not capable of meeting the current fuel specifications, let alone those of the future. The blending option of LCO prior to upgrading would adversely impact the diesel fuel, resulting in properties way far from the imposed fuel specifications. The conventional upgrading technologies (aromatic saturation and hydrocracking) have reached their full potential and can not meet the current stringent fuel specifications. Selective ring opening (SRO) approach has been proposed as an alternative. However, the studied supported catalysts such as conventional microporous zeolites, ordered mesoporous silica and mixed metal oxides for the SRO approach have met mixed success in addressing the key requirements for efficient LCO upgrading (i.e. unimpeded diffusion of reactants and products, well-balanced acidity-metal sites, strong metal-support interactions, and high thiotolerance). Therefore, developing a catalyst system that would fulfil these vital requirements is of utmost importance. Zeolite based catalysts appear to be the most promising ones.