The transesterification of palm oil and methanol catalyzed by Br?nsted acidic ionic liquids was investigated. Four eco-friendly Br?nsted acidic ionic liquids were prepared and their structures were characterized by NM...The transesterification of palm oil and methanol catalyzed by Br?nsted acidic ionic liquids was investigated. Four eco-friendly Br?nsted acidic ionic liquids were prepared and their structures were characterized by NMR, FT-IR and TG–DTG. The results demonstrated that [CyN_(1,1)PrSO_3H][p-TSA] was more efficient than the other ionic liquids and chosen as catalyst for further research. The influences of various reaction parameters on the conversion of palm oil to biodiesel were performed, and the orthogonal test was investigated to seek the optimum reaction conditions, which were illustrated as follows: methanol to oil mole ratio of 24:1, catalyst dosage of 3.0 wt% of oil, reaction temperature of 120 °C, reaction time of 150 min, and the biodiesel yield achieved 98.4%. In addition, kinetic study was established for the conversion process, with activation energy and preexponential factor of 122.93 k J·mol^(-1) and 1.83 × 10^(15), respectively. Meanwhile, seven-time recycling runs of ionic liquid were completed with ignorable loss of its catalyst activity. The refined biodiesel met the biodiesel standard EN 14214.展开更多
BrФnsted acidic ionic liquids based on imidazolium cation were employed as a series of environmentally benign catalysts and mediums in the alcoholysis of acetonitrile to synthesize ester. The results showed that BrФ...BrФnsted acidic ionic liquids based on imidazolium cation were employed as a series of environmentally benign catalysts and mediums in the alcoholysis of acetonitrile to synthesize ester. The results showed that BrФnsted acidic ionic liquid [HSO3- pmim]HSO4 was an efficient catalyst and medium for the alcoholysis of acetonitrile which could be recycled easily without obvious decline in catalytic activity, the highest yield could reach 85%.展开更多
The batch reaction experiments have been made for the first time to investigate the effect of ionic structure on the reactivity and selectivity of the trioxane-forming reaction catalyzed by a Br?nsted-acidic ionic liq...The batch reaction experiments have been made for the first time to investigate the effect of ionic structure on the reactivity and selectivity of the trioxane-forming reaction catalyzed by a Br?nsted-acidic ionic liquid(IL).The ILs considered include 1-cyclohexyl-2-pyrrolidinonium trifluoromethanesulfonate([NCy P][TfO ]),1-cyclohexyl-2-pyrrolidinonium benzenesulfonate([NCyP ][BSA]),1-cyclohexyl-2-pyrrolidinonium p-toluenesulfonate([NCyP ][pTSA]),1-octyl-2-pyrrolidinonium 2,4-dinitrobenzenesulfonate([NOP][DNBSA]),1-octyl-2-pyrrolidinonium benzenesulfonate([NOP][BSA]),1-octyl-2-pyrrolidinonium methanesulfonate([NOP][MSA]),and 1-octyl-2-pyrrolidinonium trifluoromethanesulfonate([NOP][Tf O]).It is found that the yield of trioxane in the reaction solution correlates inversely with the Hammett acidity function H0 of the aqueous solution of the corresponding ILs.Variation of the cation structure from [NCyP ]+to [NOP]+exerts little influence on the yield and the selectivity of trioxane in the reaction solution.Using [TfO ]-or [DNBSA]-in place of [MSA]-or [BSA]-apparently increases the yield of trioxane,but only slightly increases the concentration of formic acid in the reaction solution.The continuous production experiments have been made to investigate the performance of [NOP][MSA],[NOP][DNBSA],[NCyP ][TfO ],and H2SO4 as an extraction distillation agent.Such effect of [NCyP ][TfO ] considerably overrides that of H2SO4.The yield and the selectivity of trioxane are both increased when [NCyP ][TfO ] is used instead of H2SO4 at a reaction time 5 h.展开更多
A novel BrФnsted acidic ionic liquid（IL） based on the cyclic guanidinium cation has been synthesized. This IL, as a strong BrФnsted acid catalyst or solvent, shows high catalytic activity and biphsaic behavor in t...A novel BrФnsted acidic ionic liquid（IL） based on the cyclic guanidinium cation has been synthesized. This IL, as a strong BrФnsted acid catalyst or solvent, shows high catalytic activity and biphsaic behavor in the esterifications of carboxylic acids and alcohols. The produced esters as a separate phase can be conveniently decanted out from the IL and the IL is recyclable without any loss of catalytic activity.展开更多
Fructone （2-methyl-2-ethylacetoacetate-1, 3-dioxolane）, a flavouring material, has been synthesized from ethyl acetoacetate and glycol using five water-soluble Brφnsted acid ionic liquids as catalysts for the first...Fructone （2-methyl-2-ethylacetoacetate-1, 3-dioxolane）, a flavouring material, has been synthesized from ethyl acetoacetate and glycol using five water-soluble Brφnsted acid ionic liquids as catalysts for the first time. The used Brφnsted acid ionic liquids include [Hmim]Tfa, [Hmim]Tsa, [Hmim]BF4, [Bmim]HSO4, [Bmim]H2P04, and [Hmim]BF4 showed the highest catalytic activity for the preparation of fructone. After reaction, the product could be isolated from the reaction system automatically, and the ionic liquid could be directly reused without dehydration.展开更多
Novel ionic liquids with dual acidity, of which the cation contains Brφnsted acidity and anions contain Lewis acidity were synthesized. These ionic liquids obtained were identified by NMR, FF-IR, SDT and FAB-MS. Thei...Novel ionic liquids with dual acidity, of which the cation contains Brφnsted acidity and anions contain Lewis acidity were synthesized. These ionic liquids obtained were identified by NMR, FF-IR, SDT and FAB-MS. Their acidities were determined by pyridine probe on IR spectrography.展开更多
Brønsted acidic ionic liquids(ILs),N-methylimidazole hydrogen sulfate([HMIm]HSO_(4))and N-methylpyrrolidone hydrogen sulfate([HNMP]HSO_(4)),are synthesized and employed as extractants to extract thiophene from mo...Brønsted acidic ionic liquids(ILs),N-methylimidazole hydrogen sulfate([HMIm]HSO_(4))and N-methylpyrrolidone hydrogen sulfate([HNMP]HSO_(4)),are synthesized and employed as extractants to extract thiophene from model gasoline(thiophene dissolved in noctane).The effect of extraction temperature,extraction time and volume ratio of ILs to model gasoline on desulfurization rates is investigated.Then,the optimal desulfurization conditions are obtained:the ratio of ILs to model gasoline is 1∶1,extraction temperature is 50℃ for[HMIm]HSO_(4)and 60℃ for[HNMP]HSO_(4),extraction time is 60 min.Meanwhile,the desulfurization rate of[HNMP]HSO_(4)for model gasoline is 62.8%,which is higher than that of[HMIm]HSO_(4)(55.5%)under optimal conditions.The reason is discussed on the basis of the interaction energy between thiophene and ILs at the B3LYP/6-311++G(d,p)level.Furthermore,the total desulfurization rate of[HNMP]HSO_(4)and[HMIm]HSO_(4)reaches 96.4%and 94.4%,respectively,by multistage extraction.Finally,the used ILs can be reused by vacuum drying,and their desulfurization rates are not significantly decreased after recycling 7 times in single-stage desulfurization.展开更多
A novel Brφnsted acid task specific ionic liquid 1-ethylbenzimidazolium tetrafluoroborate （[Hebim]BF4） with functional benzimidazolium cation was synthesized and characterized by ^1H NMR, IR, MS spectra and element...A novel Brφnsted acid task specific ionic liquid 1-ethylbenzimidazolium tetrafluoroborate （[Hebim]BF4） with functional benzimidazolium cation was synthesized and characterized by ^1H NMR, IR, MS spectra and elemental analysis. This novel ionic liquid was successfully used as dual solvent-catalyst for the synthesis of arylic esters. Higher yields were obtained in the presence of [Hebim]BF4 in comparison with other imidazolium ionic liquids because of the good solubility of the aromatic alcohols and aromatic carboxylic acids in [Hebim]BF4. The product could be separated conveniently from the reaction system, and the ionic liquid could be easily reused after removal of water under vacuum. After 10 times reuse, the selectivity of the ester was still 100%.展开更多
基金Supported by the National Natural Science Foundation of China(21576053)the Natural Science Foundation of Fujian Province(2016J01689)the Young Teacher Education Research Foundation of Fujian Province(JAT160056)
文摘The transesterification of palm oil and methanol catalyzed by Br?nsted acidic ionic liquids was investigated. Four eco-friendly Br?nsted acidic ionic liquids were prepared and their structures were characterized by NMR, FT-IR and TG–DTG. The results demonstrated that [CyN_(1,1)PrSO_3H][p-TSA] was more efficient than the other ionic liquids and chosen as catalyst for further research. The influences of various reaction parameters on the conversion of palm oil to biodiesel were performed, and the orthogonal test was investigated to seek the optimum reaction conditions, which were illustrated as follows: methanol to oil mole ratio of 24:1, catalyst dosage of 3.0 wt% of oil, reaction temperature of 120 °C, reaction time of 150 min, and the biodiesel yield achieved 98.4%. In addition, kinetic study was established for the conversion process, with activation energy and preexponential factor of 122.93 k J·mol^(-1) and 1.83 × 10^(15), respectively. Meanwhile, seven-time recycling runs of ionic liquid were completed with ignorable loss of its catalyst activity. The refined biodiesel met the biodiesel standard EN 14214.
基金the Key Project of Chinese Ministry of Education(No.105075)
文摘BrФnsted acidic ionic liquids based on imidazolium cation were employed as a series of environmentally benign catalysts and mediums in the alcoholysis of acetonitrile to synthesize ester. The results showed that BrФnsted acidic ionic liquid [HSO3- pmim]HSO4 was an efficient catalyst and medium for the alcoholysis of acetonitrile which could be recycled easily without obvious decline in catalytic activity, the highest yield could reach 85%.
基金Supported by the National Natural Science Foundation of China(21576285,21276271)
文摘The batch reaction experiments have been made for the first time to investigate the effect of ionic structure on the reactivity and selectivity of the trioxane-forming reaction catalyzed by a Br?nsted-acidic ionic liquid(IL).The ILs considered include 1-cyclohexyl-2-pyrrolidinonium trifluoromethanesulfonate([NCy P][TfO ]),1-cyclohexyl-2-pyrrolidinonium benzenesulfonate([NCyP ][BSA]),1-cyclohexyl-2-pyrrolidinonium p-toluenesulfonate([NCyP ][pTSA]),1-octyl-2-pyrrolidinonium 2,4-dinitrobenzenesulfonate([NOP][DNBSA]),1-octyl-2-pyrrolidinonium benzenesulfonate([NOP][BSA]),1-octyl-2-pyrrolidinonium methanesulfonate([NOP][MSA]),and 1-octyl-2-pyrrolidinonium trifluoromethanesulfonate([NOP][Tf O]).It is found that the yield of trioxane in the reaction solution correlates inversely with the Hammett acidity function H0 of the aqueous solution of the corresponding ILs.Variation of the cation structure from [NCyP ]+to [NOP]+exerts little influence on the yield and the selectivity of trioxane in the reaction solution.Using [TfO ]-or [DNBSA]-in place of [MSA]-or [BSA]-apparently increases the yield of trioxane,but only slightly increases the concentration of formic acid in the reaction solution.The continuous production experiments have been made to investigate the performance of [NOP][MSA],[NOP][DNBSA],[NCyP ][TfO ],and H2SO4 as an extraction distillation agent.Such effect of [NCyP ][TfO ] considerably overrides that of H2SO4.The yield and the selectivity of trioxane are both increased when [NCyP ][TfO ] is used instead of H2SO4 at a reaction time 5 h.
文摘A novel BrФnsted acidic ionic liquid（IL） based on the cyclic guanidinium cation has been synthesized. This IL, as a strong BrФnsted acid catalyst or solvent, shows high catalytic activity and biphsaic behavor in the esterifications of carboxylic acids and alcohols. The produced esters as a separate phase can be conveniently decanted out from the IL and the IL is recyclable without any loss of catalytic activity.
基金This work was financially supported by the Key Project of Chinese Ministry of Education(No.105075)National Natural Science Foundation of China(No.20503016).
文摘Fructone （2-methyl-2-ethylacetoacetate-1, 3-dioxolane）, a flavouring material, has been synthesized from ethyl acetoacetate and glycol using five water-soluble Brφnsted acid ionic liquids as catalysts for the first time. The used Brφnsted acid ionic liquids include [Hmim]Tfa, [Hmim]Tsa, [Hmim]BF4, [Bmim]HSO4, [Bmim]H2P04, and [Hmim]BF4 showed the highest catalytic activity for the preparation of fructone. After reaction, the product could be isolated from the reaction system automatically, and the ionic liquid could be directly reused without dehydration.
基金the‘973’Program of the Chinese Ministry of Science and Technology(G-2000048002).
文摘Novel ionic liquids with dual acidity, of which the cation contains Brφnsted acidity and anions contain Lewis acidity were synthesized. These ionic liquids obtained were identified by NMR, FF-IR, SDT and FAB-MS. Their acidities were determined by pyridine probe on IR spectrography.
基金This research was financially supported by the Natural Science Fund for Colleges and Universities of Jiangsu Province(09KJB530002).
文摘Brønsted acidic ionic liquids(ILs),N-methylimidazole hydrogen sulfate([HMIm]HSO_(4))and N-methylpyrrolidone hydrogen sulfate([HNMP]HSO_(4)),are synthesized and employed as extractants to extract thiophene from model gasoline(thiophene dissolved in noctane).The effect of extraction temperature,extraction time and volume ratio of ILs to model gasoline on desulfurization rates is investigated.Then,the optimal desulfurization conditions are obtained:the ratio of ILs to model gasoline is 1∶1,extraction temperature is 50℃ for[HMIm]HSO_(4)and 60℃ for[HNMP]HSO_(4),extraction time is 60 min.Meanwhile,the desulfurization rate of[HNMP]HSO_(4)for model gasoline is 62.8%,which is higher than that of[HMIm]HSO_(4)(55.5%)under optimal conditions.The reason is discussed on the basis of the interaction energy between thiophene and ILs at the B3LYP/6-311++G(d,p)level.Furthermore,the total desulfurization rate of[HNMP]HSO_(4)and[HMIm]HSO_(4)reaches 96.4%and 94.4%,respectively,by multistage extraction.Finally,the used ILs can be reused by vacuum drying,and their desulfurization rates are not significantly decreased after recycling 7 times in single-stage desulfurization.
基金Project supported by the Key Project of Chinese Ministry of Education （No. 105075） and the National Natural Science Foundation of China （No. 20503016）.
文摘A novel Brφnsted acid task specific ionic liquid 1-ethylbenzimidazolium tetrafluoroborate （[Hebim]BF4） with functional benzimidazolium cation was synthesized and characterized by ^1H NMR, IR, MS spectra and elemental analysis. This novel ionic liquid was successfully used as dual solvent-catalyst for the synthesis of arylic esters. Higher yields were obtained in the presence of [Hebim]BF4 in comparison with other imidazolium ionic liquids because of the good solubility of the aromatic alcohols and aromatic carboxylic acids in [Hebim]BF4. The product could be separated conveniently from the reaction system, and the ionic liquid could be easily reused after removal of water under vacuum. After 10 times reuse, the selectivity of the ester was still 100%.
