Molecular Level\nSimulation of the Conversion and Distribution\nof Sulfides in the Fluid Catalytic Cracking and Hydrotreating Processes\nto Improve the Cleanliness of Gasoline and Diesel

Abstract

To meet the requirements of fuel standards, the coupling\nsimulations\nof fluid catalytic cracking (FCC) and hydrotreating processes were\ncarried out to analyze the conversion and distribution of sulfides\nat the molecular level to improve the cleanliness of gasoline and\ndiesel. According to the structure-oriented lumping (SOL) method and\nthe reaction mechanism, the transformation laws and distributions\nof sulfides in gasoline and diesel were studied. When the FCC reaction\ntemperature increased, the content of dimethyl-thiophene in heavy\ngasoline and the content of dimethyl-dibenzothiophene in diesel increased\ndue to the stronger promotion of high temperature to the side chain\ncracking reactions. As gasoline hydrotreating reaction temperature\nrose from 220 to 280 °C, the content of dimethyl-thiophene in\nheavy gasoline reduced from 4.77 to 0.98 mg/kg since higher temperature\npromotes the hydrodesulfurization reactions. The coupling simulation\ncould provide effective guidance at the molecular level for reducing\nthe content of sulfides in heavy gasoline and diesel.