Ionic Liquid Is Used For Fcc Gasoline Desulfurization Research

Catalytic hydrodesulfurization (HDS) is the most widely used oil desulfurization technology in the world, but the removal effect of the technology on thiophene compounds is not very nice. As a kind of low temperature molten salt, ionic liquids which compose of organic cations and inorganic anions are in a liquid state of salt at or near room temperature and have difficult volatile and low steam pressure. We can design the appropriate ionic liquids no pollution to the environment according to different needs. For the above reasons, more researchers pay attention to ionic liquids. Although ionic liquids has been widely used in the field of extraction and separation, the use of fuel desulfurization is still in studies. In the21st century, because of paying more and more attention to environmental protection, our country made specific requirements to the sulfur content of the automobile emission and established the discharge standards integrating with the European and American developed country. As the main component of our country fuel, the sulfur content of FCC gasoline is relatively taller, which leads to obstacles to the development of China’s clean oil, therefore, the research of the product depth desulphurization is so imminent.This experiment mainly studies the synthesis of ionic liquids and the application of fuel desulfurization.Firstly, by using microwave method with N-methylimidazole and chloralkane as the raw materials, we synthetised three kinds of ionic liquids which is relatively [EMIMJPF6[BMIM]PF6,[HMIM]PF6. we studied the single factor’s influence on the synthetised ionic liquid intermediates [BMIM]C1yield. At the same time, by optimizing the synthetic conditions with the orthogonal design, we determined the optimum conditions of synthetizing [BMIM]C1:microwave power400W, intermittent reaction time150s, the substance amount ratio of N-methylimidazole and chloralkane1:1.2, the yield94.32%.Secondly, we made structure characterization and analysis to the three kinds of ionic liquids synthesised by Fourier transform infrared spectrum (FTIR).Thirdly, we did some experiments simulating oil oxidation extraction desulfurization with ionic liquid [HMIM]PF6. By doing single factor analysis to oxidation extraction conditions, we confirmed the optimum desulfurization conditions:microwave power W=400w, the reaction temperature T=55℃, the catalyst to oil ratio=1.2:1, reaction time t=15min, oxidant amount V (H202)=2.5mLUltimately, we used response surface methodology to optimize desulfurization conditions. By designing Plackett-Burman experimental, we got three significant influence factors to oxidation desulfurization efficiency, which is respectively t (reaction time), the catalyst to oil ratio and T (reaction temperature). By designing Box-Behnken experimental, we confirmed the optimum reaction conditions:the catalyst to oil ratio=1.2, T=54.58℃, t=14.55min, the optimal desulfurization rate=96.32%. We used the optimum desulfurization conditions to perform the oxidative-extraction desulfurization once more and obtained the actual desulfurization rate94.78%.