The procedures of ultrasonic extraction and clean-up were optimized for the determination of polycyclic aromatic hydrocarbons (PAHs) in marine sediments. Samples were ultrasonically extracted, and the extracts were pu...The procedures of ultrasonic extraction and clean-up were optimized for the determination of polycyclic aromatic hydrocarbons (PAHs) in marine sediments. Samples were ultrasonically extracted, and the extracts were purified with a miniaturized silica gel chromatographic column and analyzed with high performance liquid chromatography (HPLC) with a fluorescence detector. Ultrasonication with methanol-dichloromethane (2:1, v/v) mixture gave higher extraction efficiency than that with dichloromethane. Among the three elution solvents used in clean-up step, dichloromethane-hexane (2:3, v/v) mixture was the most satisfactory. Under the optimized conditions, the recoveries in the range of 54.82% to 94.70% with RSDs of 3.02% to 23.22% for a spiked blank, and in the range of 61.20% to 127.08% with RSDs of 7.61% to 26.93% for a spiked matrix, were obtained for the 15 PAHs studied, while the recoveries for a NIST standard reference SRM 1941b were in the range of 50.79% to 83.78% with RSDs of 5.24% to 21.38%. The detection limits were between 0.75 ng L-1 and 10.99 ng L-1for different PAHs. A sample from the Jiaozhou Bay area was examined to test the established methods.展开更多
Because of its high density and low cetane number, the light cycle oil(LCO) containing heavy aromatics(60%—80%) can hardly be transformed through the conventional hydro-upgrading technology. In this report, a novel L...Because of its high density and low cetane number, the light cycle oil(LCO) containing heavy aromatics(60%—80%) can hardly be transformed through the conventional hydro-upgrading technology. In this report, a novel LCO hydrocracking technology(FD2G) was proposed for the utilization of LCO to manufacture high value-added products. Through the ingenious combination of hydroprocessing catalyst and the hydrocracking process, the high octane gasoline and the ultra-low sulfur diesel(ULSD) blendstocks were produced simultaneously. The influence of catalyst type, reaction temperature, pressure, respectively, on the research octane number(RON) of produced gasoline was studied in a fixed bed hydrogenation reactor. It indicated that high reaction temperature and medium pressure would favor the production of highoctane gasoline through the conversion of bi-aromatic and tri-aromatic hydrocarbons. The typical results of FD2 G technology on commercial units showed that it could produce clean diesel with a sulfur content of less than 10 μg/g and clean gasoline with a research octane number(RON) of up to 92. It would be contributed to the achievement of the maximum profit of a refinery, the FD2 G technology could provide a higher economic efficiency than the other diesel quality upgrading technology under the current gasoline and diesel price system.展开更多
基金supported by the National Natural Science Foundation of China (Grant No.20775074)
文摘The procedures of ultrasonic extraction and clean-up were optimized for the determination of polycyclic aromatic hydrocarbons (PAHs) in marine sediments. Samples were ultrasonically extracted, and the extracts were purified with a miniaturized silica gel chromatographic column and analyzed with high performance liquid chromatography (HPLC) with a fluorescence detector. Ultrasonication with methanol-dichloromethane (2:1, v/v) mixture gave higher extraction efficiency than that with dichloromethane. Among the three elution solvents used in clean-up step, dichloromethane-hexane (2:3, v/v) mixture was the most satisfactory. Under the optimized conditions, the recoveries in the range of 54.82% to 94.70% with RSDs of 3.02% to 23.22% for a spiked blank, and in the range of 61.20% to 127.08% with RSDs of 7.61% to 26.93% for a spiked matrix, were obtained for the 15 PAHs studied, while the recoveries for a NIST standard reference SRM 1941b were in the range of 50.79% to 83.78% with RSDs of 5.24% to 21.38%. The detection limits were between 0.75 ng L-1 and 10.99 ng L-1for different PAHs. A sample from the Jiaozhou Bay area was examined to test the established methods.
文摘Because of its high density and low cetane number, the light cycle oil(LCO) containing heavy aromatics(60%—80%) can hardly be transformed through the conventional hydro-upgrading technology. In this report, a novel LCO hydrocracking technology(FD2G) was proposed for the utilization of LCO to manufacture high value-added products. Through the ingenious combination of hydroprocessing catalyst and the hydrocracking process, the high octane gasoline and the ultra-low sulfur diesel(ULSD) blendstocks were produced simultaneously. The influence of catalyst type, reaction temperature, pressure, respectively, on the research octane number(RON) of produced gasoline was studied in a fixed bed hydrogenation reactor. It indicated that high reaction temperature and medium pressure would favor the production of highoctane gasoline through the conversion of bi-aromatic and tri-aromatic hydrocarbons. The typical results of FD2 G technology on commercial units showed that it could produce clean diesel with a sulfur content of less than 10 μg/g and clean gasoline with a research octane number(RON) of up to 92. It would be contributed to the achievement of the maximum profit of a refinery, the FD2 G technology could provide a higher economic efficiency than the other diesel quality upgrading technology under the current gasoline and diesel price system.
