Study On Deep Reactive Adsorption Desulfurization And Olefin Reduction Of FCC Gasoline

Automobile emission is an important factor to the content of PM2.5in the atmosphere. FCC gasoline is the main component of motor gasoline, in which the sulfur and olefin content are out of limits. To minimize the emission of harmful substance and ensure the quality of oil, deep reactive adsorption desulfurization and olefin reduction of FCC gasoline were studied.The desulfurization effect of adsorbents was investigated on a fixed-fluidized reactor. When the desulfurization rate reduced to90%, the reaction time of fresh adsorbents was330min, the adsorption amount was11.09mg/g and the sulfur content of refined oil was11.58mg/g, while the reaction time of patent adsorbents was380min, the adsorption amount was12.80mg/g and the sulfur content of refined oil was9.44mg/g. Then do research about the influences of olefins on desulfurization rate of adsorbents. Different types and content of olefins would affect different. The properties of FCC gasoline and refined oil were determined. Then contrast the desulfurization effect in lab with industry. The results showed that the sulfur content of refined oil in industry (4.31mg·L-1) was lower than in lab (11.58mg·L-1). The desulfurization effect of fresh adsorbents which were prepared in lab was less than the patent adsorbents, but less loss of1.8units of octane number (RON).Characterize adsorbents by SEM, BET etc. The mechanism of adsorption desulfurization reaction was investigated. The phenomenon, such as adsorption reunion, carbon depodition. ZnSx generation and so on, occurred to the used adsorbents. Further analysis. the Ni and ZnO of adsorbents played a role in the desulfurization process. ZnO was the ultimate recipient of the sulfur.On this basis, etherification of FCC gasoline after desulfurization and methanol was studied on a lab fixed reactor. Hβzeolite was screened as the catalyst of the etherification. The optimized operating conditions were:methanol olefin molar ratio of1.05. temperature of75℃. reaction pressure of lMpa and WHSV of1h-1. In these conditions, the olefin conversion of FCC light gasoline was22.03%. Only20.9%of the tertiary carbon olefin in FCC light can participate in the etherfication reaction. After etherfication, the content of olefin decreased from41.16%to32.09%and the research octane increased from96.07to97.11. The distillate oil was the mixture of etherfication oil and heavy oil. The content of olefin in distillate oil was35.71%, as to the industrial refined oil41.74%. Octane number increased from90.23to90.68.