Development of technology for converting fuel oil to aromatics

摘要

Global demand for aromatic compounds is increasing annually. Meanwhile, fuel oil demand is gradually decreasing in Japan. This situation prompted us to develop a technology for producing aromatic products efficiently from LCO (Light Cycle Oil from FCC units), which is widely used as a blending stock in the fuel oil pool. The LCO-HDC (hydrocracking) process is a newly-developed petroleum refining technology for converting LCO into heavy naphtha, which can be further converted into aromatic products such as BTX (Benzene, Toluene and Xylene) in reforming units. In adopting the LCO-HDC technology, knowledge gained over years of experience in operating VGO (Vacuum Gas Oil)-HDC units proved valuable in various ways. Since LCO contains more polycyclic aromatics than does VGO, two reactions are critical for promoting aromatics production from LCO: hydrogenation and hydrocracking. In VGO-HDC units, the catalyst systems consist of both hydrogenation catalysts and hydrocracking catalysts. We found that, by modifying both the hydrogenation and hydrocracking catalysts, it was possible to develop catalyst systems which are more suitable for LCO-HDC than existing catalyst systems for VGO-HDC. A key feature of the new hydrogenation catalyst is its support material. Meanwhile, with the hydrocracking catalyst, higher activity was achieved by modifying the zeolite.