The Development Of Selective Hydrodesulfurization Technology (RSDS) For FCC Gasoline And Its Industrial Application

This paper made a comprehensive overview on the trend of the quality of vehicle gasoline at home and abroad, and the technology development and application on FCC gasoline desulfurization technologies. Based on the background of satisfying the need for producing clean gasoline to meet the EuroⅣ/Shanghai-Ⅳ(S<50μg/g) standard in Shanghai Petrochemical Company, we carried out the research on the catalytic gasoline desulfurization technology, by cooperating with Beijing Research Institute of Petroleum (RIPP). The distribution of sulfur and olefin in catalytic gasoline was studied, the correlation of sulfur content in FCC gasoline was established, the main factors on the product sulfur and olefin content to be the cut points of gasoline and the desulfurization rate of light and heavy fractions were specified, and the fractionation of light and heavy fractions in FCC gasoline were confirmed, applying alkaline extraction desulfurization for light gasoline fractions, and applying hydro desulfurization for heavy gasoline fraction to reduce the sulfur content of catalytic gasoline. The influence of different desulfurization technologies and hydrogenation catalysts on the sulfur and olefin content of gasoline was investigated, selective hydrodesulfurization technology (RSDS-Ⅰ) for FCC gasoline was developed and its first industrial experiment was carried out in Shanghai Petrochemical Company. The results showed that the RSDS-Ⅰtechnology had superior desulfurization ability and good selectivity, the operation is flexible and reliable. According to the variation of sulfur content in FCC gasoline as feedstock and the specific circumstances of the devices, Euro IV requirements can be achieved through reasonable adjustments of the cut points of light and heavy fractions and the hydrogenation conditions. The technology has the advantages on both high yield on gasoline and low hydrogen consumption. For reducing the loss of gasoline RON while making a further improvement of the desulfurization rate, the research of 2nd generation RSDS-Ⅱon industrial application was also carried out. The results showed that RSDS-Ⅱhad better desulfurization selectivity than RSDS-Ⅰ, and the RON loss had a further reduction when total desulfurization rate exceeded 95%. In conclusion, RSDS-Ⅱhas superior desulfurization selectivity, low loss of RON in the condition of deep desulfurization, and can fully satisfy the need of producing in EuropeⅣ/ShanghaiⅣ(S<50μg/g) of clean gasoline. The success of the industrial application of RSDS-Ⅱcan provide a good model for its further promotion.