The extractive removal of sulfur compounds （S-compounds） from Dongying and Liaohe diesel fuels with [BF4]^--based ionic liquids were systematically investigated. The results show that the absorption capacity of an i...The extractive removal of sulfur compounds （S-compounds） from Dongying and Liaohe diesel fuels with [BF4]^--based ionic liquids were systematically investigated. The results show that the absorption capacity of an ionic liquid for the S-compounds in diesel fuels relies on its structure and its size. In the case of the two examined diesel fuels, both elongating the cation tail length and increasing the mass ratio of ionic liquid/diesel fuel promote the desulfurization ability of the examined ionic liquids. The results also show that imidazolium-based ionic liquids display higher extraction efficiencies than pyridinium-based ionic liquids, presumably owing to the fact that the rings of the S-compounds are similar to the imidazolium head ring. With the 1 ： 1 mass ratio of ionic liquid/diesel fuel, the rates of the first desulfurization of Dongying and Liaohe diesel fuels using [C8mim][BF4] amount to 29.96% and 39.76%, suggesting that [C8mim][BF4] is a promising extractant for desulfurization of these diesel fuels.展开更多
The density, viscosity and conductivity of ionic liquids （ILs）, 1-octyl-3-methylimidazolium tetrafluoroborate （[omim][BF4]）, 1-octyl-3-methylimidazolium chloride （[omim][C1]）, 1-hexyl-3-methylimidazolium tetrafl...The density, viscosity and conductivity of ionic liquids （ILs）, 1-octyl-3-methylimidazolium tetrafluoroborate （[omim][BF4]）, 1-octyl-3-methylimidazolium chloride （[omim][C1]）, 1-hexyl-3-methylimidazolium tetrafluoroborate （[hmim] BF4]）, 1-hexyl- 3-methylimidazolium chloride （[hmim][C1]）, 1-hexyl-3-methylimidazolium hexafluorophosphate （[hmim][PF6]）, and the [omim][BF4] ＋ [omim][Cl], [hmim][BF4] ＋ [hmim][C1], and [hmim][PF6] ＋ [hmim][C1] binary mixtures were studied at dif- ferent temperatures. It was demonstrated that the densities of both the neat ILs and their mixtures varied linearly with temper- ature. The density sensitivity of a binary mixture is between those of the two components. The excess molar volumes （l/e） of [hmim][BF4] ＋ [hmim][C1] and [hmim][PF6] ＋ [hmim][C1] mixtures are positive in the whole composition range. For [omim][BF4] ＋ [omim][C1], the VE is also positive in the [omirn][C1]-rich region, but is negative in the [omim][BF4]-rich re- gion. The viscosity or conductivity of a mixture is in the intermediate of those of the two neat ILs. For all the neat ILs and the binary mixtures studied, the order of conductivity is opposite to that of the viscosity. The Vogel-Tammann-Fulcher （VTF） equations can be used to fit the viscosity and conductivity of all the neat ILs and the binary mixtures. The neat ILs and their mixtures obey the Fractional Walden Rule very well, and the values of the Walden slopes are all smaller than unit, indicating obvious ion associations in the neat ILs and the binary mixtures.展开更多
基金Supported by the National Natural Science Foundation of China （40673043, 20576073）, CNPC Innovation Fund （04E7031）, and the Program for New Century Excellent Talents in University of Ministry of Education of China （NCET-06-0088）.
文摘The extractive removal of sulfur compounds （S-compounds） from Dongying and Liaohe diesel fuels with [BF4]^--based ionic liquids were systematically investigated. The results show that the absorption capacity of an ionic liquid for the S-compounds in diesel fuels relies on its structure and its size. In the case of the two examined diesel fuels, both elongating the cation tail length and increasing the mass ratio of ionic liquid/diesel fuel promote the desulfurization ability of the examined ionic liquids. The results also show that imidazolium-based ionic liquids display higher extraction efficiencies than pyridinium-based ionic liquids, presumably owing to the fact that the rings of the S-compounds are similar to the imidazolium head ring. With the 1 ： 1 mass ratio of ionic liquid/diesel fuel, the rates of the first desulfurization of Dongying and Liaohe diesel fuels using [C8mim][BF4] amount to 29.96% and 39.76%, suggesting that [C8mim][BF4] is a promising extractant for desulfurization of these diesel fuels.
基金supported by the National Natural Science Foundation of China (21133009, 21073207, 20903109)
文摘The density, viscosity and conductivity of ionic liquids （ILs）, 1-octyl-3-methylimidazolium tetrafluoroborate （[omim][BF4]）, 1-octyl-3-methylimidazolium chloride （[omim][C1]）, 1-hexyl-3-methylimidazolium tetrafluoroborate （[hmim] BF4]）, 1-hexyl- 3-methylimidazolium chloride （[hmim][C1]）, 1-hexyl-3-methylimidazolium hexafluorophosphate （[hmim][PF6]）, and the [omim][BF4] ＋ [omim][Cl], [hmim][BF4] ＋ [hmim][C1], and [hmim][PF6] ＋ [hmim][C1] binary mixtures were studied at dif- ferent temperatures. It was demonstrated that the densities of both the neat ILs and their mixtures varied linearly with temper- ature. The density sensitivity of a binary mixture is between those of the two components. The excess molar volumes （l/e） of [hmim][BF4] ＋ [hmim][C1] and [hmim][PF6] ＋ [hmim][C1] mixtures are positive in the whole composition range. For [omim][BF4] ＋ [omim][C1], the VE is also positive in the [omirn][C1]-rich region, but is negative in the [omim][BF4]-rich re- gion. The viscosity or conductivity of a mixture is in the intermediate of those of the two neat ILs. For all the neat ILs and the binary mixtures studied, the order of conductivity is opposite to that of the viscosity. The Vogel-Tammann-Fulcher （VTF） equations can be used to fit the viscosity and conductivity of all the neat ILs and the binary mixtures. The neat ILs and their mixtures obey the Fractional Walden Rule very well, and the values of the Walden slopes are all smaller than unit, indicating obvious ion associations in the neat ILs and the binary mixtures.
