| 초록 |
The oil industry is under increasing pressure from the automobile company and the environmental protection agencies to improve the quality of diesel fuel with a view to reduce NOx content in the exhaust gas in the combustion of diesel fuel. Tighter sulfur specifications for diesel fuel have been therefore introduced in many countries in the last few years, and further tightening of sulfur specifications is planned over the next few years[1,2]. Until now, the hydrodesulfurization(HDS) process is most commonly used to reduce sulfur content in diesel fuel by converting sulfur compounds into hydrogen sulfide[3∼5], however this process has some problems to use directly for the ultra-low sulfur diesel (< 50 ppm sulfur) manufacture. Recently, there are some reports that HDS process will successfully applied for producing of ultra-low sulfur diesel, if heterocyclic nitrogen-containing compounds, which are inhibitor for desulfurization process, in the middle distillate feedstock removed effectively. Adsorption an d solvent extraction could be one of the solutions to remove these nitrogen-containing compounds from middle distillates. Solvent extraction may have some advantages to the adsorption for removing nitrogen compounds, because it will be operated at the condition of atmospheric pressure and moderate temperature ranges. Besides it needs not additional catalyst. In this study, tie-line end compositions for 6 different heterocyclic compounds containing systems, methanol(1)+hexadecane(2)+nitrogen-containing compounds(3) were experimentally determined at 298.15K. N-hexadecane(cetane) was taken as the model compound for diesel fuel and quinoline, pyridine, acridine, indole, pyrrole and aniline were taken as the basic and non-basic heterocylic nitrogen-containing compounds in the middle distillate feedstock. |
