Desulfurization from cracking of gasoline via selective oxidation catalyzed by phase tranfer catalyst is investigated.Using cetyltrimethyl ammonium bromide(CTAB) as the phase transfer catalyst,hydrogen peroxide as the...Desulfurization from cracking of gasoline via selective oxidation catalyzed by phase tranfer catalyst is investigated.Using cetyltrimethyl ammonium bromide(CTAB) as the phase transfer catalyst,hydrogen peroxide as the oxidant,acetic anhydride as the assistant oxidant,the effects of different conditions,such as reaction time,reaction temperature,the content of phase transfer catalyst,on the desulfurization rate are investigated.When the volume ratio of gasoline and oxidative system is 0.2,the volume ratio of hydrogen peroxide and acetic anhydride is 5,the content of phase transfer catalysis is 0.06 g,reaction time is 0.5 h,the desulfurization rate of the FCC gasoline is 80.13%.After analyzed by GC-FPD,there is no oxidized sulfur-containing compounds remained in the gasoline.展开更多
为改善纤维素原料的亲水性,提高纤维素的可及度,将具有强亲水性的聚醚引入离子液体合成出系列聚醚功能化双核咪唑类离子液体,并将其应用于纤维素的预处理和糖化研究。相对于在咪唑类离子液体中引入烯丙基、烷基、羧酸以及乙酸乙酯等阳...为改善纤维素原料的亲水性,提高纤维素的可及度,将具有强亲水性的聚醚引入离子液体合成出系列聚醚功能化双核咪唑类离子液体,并将其应用于纤维素的预处理和糖化研究。相对于在咪唑类离子液体中引入烯丙基、烷基、羧酸以及乙酸乙酯等阳离子功能化基团,聚醚基团的烷氧基(CH2—CH2—O)可增大离子液体与纤维素的有效接触,并作为氢键受体促进纤维素中原有氢键的破坏;分子质量为400的聚乙二醇(PEG400)可提供足够数量和极化强度的氢原子改善亲水性;相对于单核咪唑类,双核咪唑类离子液体醚基上的次甲基氢原子的极性增强(E_T(30),61.33 kcal/mol),形成更高的氢键酸度(α,2.792);聚醚功能化双核咪唑类离子液体([PEG400-(Et-Im)_2][Cl]_2)对纤维素溶解度高达13.26%质量分数。相对于HCOO^-、Cl^-和Br^-阴离子功能化,OAc^-功能化的[PEG400-(Et-Im)_2][OAc]_2具有更大的氢键碱度(β,1.04),增加了对纤维素羟基上氢键的接受能力;聚醚的烷氧基会带来较低的黏度(63 c P,120℃),黏度表观活化能(E_η)为30.11 k J/mol,促进了离子液体与纤维素的接触与物质传输,由此获得[PEG400-(Et-Im)2][OAc]_2对纤维素的高溶解度(14.76%质量分数)。纤维素在[PEG400-(Et-Im)_2][OAc]_2溶解过程中没有发生衍生化反应,纤维素的结晶度由85.4%降至31.6%,实现了高结晶有序结构向无定型的转化。得到的再生纤维素膜具有各向同性和均一致密的性能,热力学稳定性稍有下降。酸性聚醚功能化离子液体[PEG400-(Et-Im)_2][HSO4]_2催化纤维素水解中葡萄糖得率为55.8%。展开更多
文摘Desulfurization from cracking of gasoline via selective oxidation catalyzed by phase tranfer catalyst is investigated.Using cetyltrimethyl ammonium bromide(CTAB) as the phase transfer catalyst,hydrogen peroxide as the oxidant,acetic anhydride as the assistant oxidant,the effects of different conditions,such as reaction time,reaction temperature,the content of phase transfer catalyst,on the desulfurization rate are investigated.When the volume ratio of gasoline and oxidative system is 0.2,the volume ratio of hydrogen peroxide and acetic anhydride is 5,the content of phase transfer catalysis is 0.06 g,reaction time is 0.5 h,the desulfurization rate of the FCC gasoline is 80.13%.After analyzed by GC-FPD,there is no oxidized sulfur-containing compounds remained in the gasoline.
文摘为改善纤维素原料的亲水性,提高纤维素的可及度,将具有强亲水性的聚醚引入离子液体合成出系列聚醚功能化双核咪唑类离子液体,并将其应用于纤维素的预处理和糖化研究。相对于在咪唑类离子液体中引入烯丙基、烷基、羧酸以及乙酸乙酯等阳离子功能化基团,聚醚基团的烷氧基(CH2—CH2—O)可增大离子液体与纤维素的有效接触,并作为氢键受体促进纤维素中原有氢键的破坏;分子质量为400的聚乙二醇(PEG400)可提供足够数量和极化强度的氢原子改善亲水性;相对于单核咪唑类,双核咪唑类离子液体醚基上的次甲基氢原子的极性增强(E_T(30),61.33 kcal/mol),形成更高的氢键酸度(α,2.792);聚醚功能化双核咪唑类离子液体([PEG400-(Et-Im)_2][Cl]_2)对纤维素溶解度高达13.26%质量分数。相对于HCOO^-、Cl^-和Br^-阴离子功能化,OAc^-功能化的[PEG400-(Et-Im)_2][OAc]_2具有更大的氢键碱度(β,1.04),增加了对纤维素羟基上氢键的接受能力;聚醚的烷氧基会带来较低的黏度(63 c P,120℃),黏度表观活化能(E_η)为30.11 k J/mol,促进了离子液体与纤维素的接触与物质传输,由此获得[PEG400-(Et-Im)2][OAc]_2对纤维素的高溶解度(14.76%质量分数)。纤维素在[PEG400-(Et-Im)_2][OAc]_2溶解过程中没有发生衍生化反应,纤维素的结晶度由85.4%降至31.6%,实现了高结晶有序结构向无定型的转化。得到的再生纤维素膜具有各向同性和均一致密的性能,热力学稳定性稍有下降。酸性聚醚功能化离子液体[PEG400-(Et-Im)_2][HSO4]_2催化纤维素水解中葡萄糖得率为55.8%。
