The production of high-purity propylene glycol monomethyl ether acetate(PMA)through the transesterification of propylene glycol monomethyl ether(PM)and methyl acetate(MeOAc)is traditionally catalyzed by sodium methoxi...The production of high-purity propylene glycol monomethyl ether acetate(PMA)through the transesterification of propylene glycol monomethyl ether(PM)and methyl acetate(MeOAc)is traditionally catalyzed by sodium methoxide.However,the practical application of this method is significantly hindered by the inherent limitations of sodium methoxide,such as its high sensitivity to moisture and propensity for solid precipitation,which impede its effective use in continuous processes.This work proposed a continuous catalytic distillation(CD)process utilizing Amberlyst 15 cation exchange resin as the catalyst.A comprehensive series of reaction kinetic and CD experiments were conducted to evaluate the performance of the proposed process.The results demonstrate that under the optimal operating conditions,namely an ester-to-ether molar ratio of 6:1,a refluxratio of 5:1,a total feed rate of 0.92 g‧min^(-1),and an evaporation rate of 266.47 m^(3)‧m^(-2)‧h^(-1),the conversion rate of PM achieves 99.95%,and the PMA yield is 97.31%.Based on these findings,a process flowsheet for a continuous CD process tailored for the production of electronic-grade PMA is presented.This design incorporates light and heavy removal steps to ensure the production of PMA with a purity of 99.99%.Additionally,the process utilizes pressure swing distillation to recover MeOAc,thereby enhancing the overall efficiencyand sustainability of the production process.The proposed continuous CD process offers a highly efficient,cost-effective,and environmentally sustainable solution for the production of electronic-grade PMA.展开更多
Dimethyl carbonate(DMC)is an important chemical raw material extensively used in organic synthesis,lithium-ion battery electrolytes,etc.The primary method for industrial synthesis of DMC involves transesterification b...Dimethyl carbonate(DMC)is an important chemical raw material extensively used in organic synthesis,lithium-ion battery electrolytes,etc.The primary method for industrial synthesis of DMC involves transesterification between ethylene carbonate and MeOH but faces issues with difficult catalyst separation and low catalytic activity.Based on the synergistic catalytic activity of cation and anion,this study develops poly(ionic liquid)s of[N_(X)PIL][PHO]and[N_(3)PIL][Y]with varying alkaline sites and alkalinity levels.This is accomplished by constructing functional polymer monomers containing free radical polymerization sites and nitrogencontaining alkaline groups,and by polymerizing them with suitable crosslinking monomers in a specific ratio before exchanging the resulting polymers with different anions.Results show that doping with nitrogen-containing alkaline groups leads to enhanced basic functional sites while appropriate anions provide intensified alkalinity levels.The[N_(3)PIL][PHO]obtained exhibits superior catalytic activity in transesterification synthesis of DMC,with a yield of 91.43%and selectivity of 99.96%at a reaction time of 2 h.The study also investigates the impact of poly(ionic liquid)cationic structure and anion types,as well as their interactions,on catalytic performance.The findings reveal that the catalytic activity of poly(ionic liquid)is restricted by the interactions between cation and anion.Based on these findings,a possible reaction mechanism was proposed,providing theoretical support for the high-efficiency production of DMC.展开更多
Designing efficient adsorbents for the deep removal of refractory dibenzothiophene(DBT)from fuel oil is vital for addressing environmental issues such as acid rain.Herein,zinc gluconate and urea-derived porous carbons...Designing efficient adsorbents for the deep removal of refractory dibenzothiophene(DBT)from fuel oil is vital for addressing environmental issues such as acid rain.Herein,zinc gluconate and urea-derived porous carbons SF-ZnNC-T(T represents the carbonization temperature)were synthesized without solvents.Through a temperature-controlled process of“melting the zinc gluconate and urea mixture,forming H-bonded polymers,and carbonizing the polymers,”the optimal carbon,SF-ZnNC-900,was obtained with a large surface area(2280 m^(2)g^(-1),highly dispersed Zn sites,and hierarchical pore structures.Consequently,SF-ZnNC-900 demonstrated significantly higher DBT adsorption capacity of43.2 mg S g^(-1),compared to just 4.3 mg S g^(-1)for the precursor.It also demonstrated good reusability,fast adsorption rate,and the ability for ultra-deep desulfurization.The superior DBT adsorption performance resulted from the evaporation of residual zinc species,which generated abundant mesopores that facilitated DBT transformation,as well as the formation of Zn-N_(x) sites that strengthened the host-vip interaction(ΔE=-1.466 e V).The solvent-free synthesized highly dispersed Zn-doped carbon shows great potential for producing sulfur-free fuel oil and for designing metal-loaded carbon adsorbents.展开更多
The solid acid SO_4^(2-)/TiO_2 was prepared by immersion method and applied for synthesis of propylene glycol methyl ether acetate(PMA) through esterification reaction of propylene glycol monomethyl ether(PM)and aceti...The solid acid SO_4^(2-)/TiO_2 was prepared by immersion method and applied for synthesis of propylene glycol methyl ether acetate(PMA) through esterification reaction of propylene glycol monomethyl ether(PM)and acetic acid(HAc). The optimal catalyst preparation condition was determined by orthogonal analysis of parameters in a five-factor and four-level test. The obtained solid acid catalysts were characterized in detail by means of X-ray powder diffraction, thermogravimetry, pyridine adsorbed IR analysis, scanning electron microscopy, and BET surface area method. Synthesis of PMA was studied in this paper through experimental investigation of reaction conditions such as temperature, molar ratio of reactants, catalyst dosage and agitation speed. Based on its possible reaction mechanism, a pseudo-homogeneous kinetic model was established and its activation energies E_a^+ and E_a^-,65.68 × 10~3J·mol^(-1) and 57.78 × 10~3J·mol^(-1), were estimated. To prepare shaped solid acid catalyst SO_4^(2-)/TiO_2, the shaping method of impregnation–shaping–impregnation was applied. The optimal molding formulation of solid acid catalyst, obtained from the orthogonal test, was found to be binder 7 wt%, reinforcing agent 20 wt%, pore forming material 2.5 wt%, and lubricant 4 wt%.The results of performance test of catalyst demonstrated that the shaped solid acid catalyst exhibited high activity and stability.展开更多
A series of polymeric ionic liquids(PILs)used as effective heterogeneous catalysts for biodiesel production via esterification of free fatty acids(FFAs)were effectively prepared by the reaction of poly(ethylene imine)...A series of polymeric ionic liquids(PILs)used as effective heterogeneous catalysts for biodiesel production via esterification of free fatty acids(FFAs)were effectively prepared by the reaction of poly(ethylene imine)(PEI)polymers with different molecular weight and 1,3-propanesultone,followed by the further acidification with differential effective acids,i.e.H2SO4,CF3SO3H,CH3SO3H or p-toluenesulfonic acid(p-TSA).Ultrahigh acidity and catalytic performance were achieved and could be fine-tuned by simply adjusting the molecular weight of PEI and by further treatment of acids.Specifically,under the optimal conditions(i.e.reaction temperature was 70℃,reaction time was 2.0 h,catalyst dosage was 3.15%(mass),and alcohol/acid molar ratio was 14:1)acquired through the Box-BEHNKEN response surface methodology,a high oleic acid conversion of 98.42%could be obtained over the optimal PIL,PEI(70000)-PS-p-TSA.Additionally,our PILs also showed high generality for esterification of other FFAs,with general high conversion over 90%noted in each case even under much milder reaction conditions compared to other conventional catalysts.展开更多
Photocatalytic removal of tetracycline(TC)from the wastewater is of great value in the chemical and environmental engineering field.Here,we introduced a facile one-step method for the synthesis of BiOBr/Bi2WO6 heteroj...Photocatalytic removal of tetracycline(TC)from the wastewater is of great value in the chemical and environmental engineering field.Here,we introduced a facile one-step method for the synthesis of BiOBr/Bi2WO6 heterojunctions by using cheap CTAB as the Br source.We showed the possibility of our method to fine-tune the content of BiOBr in the produced BiOBr/Bi2WO6 by simply changing the dosage of cetyltrimethylammonium bromide(CTAB),providing a platform for the delicate tuning of the visiblelight absorbance ability of the composites.With a suitable heterojunction structure of BiOBr/Bi2WO6-0.2,it exhibited an ultrarapid photocatalytic activity towards TC(20 mgL^(-1)),with a competitive removal efficiency of 88.1%within 60 min and an ultrahigh removal rate of 0.0349 min^(-1).It could also be robustly recycled for at least 5 cycles with slight removal efficiency loss.We demonstrated that this exciting photocatalytic performance was due to the highly decreased recombination of photoinduced electrons and holes on our composites by constructing this heterojunction structure,and the resultingOH andO^(-)_(2)contributed to the effective degradation of TC to CO_(2).展开更多
Dimethyl carbonate is an environmentally benign and biodegradable chemical.Based on integration of reactive distillation and pressure-swing distillation technologies,a novel process for synthesis of dimethyl carbonate...Dimethyl carbonate is an environmentally benign and biodegradable chemical.Based on integration of reactive distillation and pressure-swing distillation technologies,a novel process for synthesis of dimethyl carbonate through transesterification with propylene carbonate and methanol has been developed by Huang et al.In this work,the optimization of this process was performed by minimizing the total TAC.The results show that the optimal design flowsheet can save energy consumption by 18.6% with the propylene carbonate conversion of 99.9%.Then,an effective plant-wide control structure for the process was developed.Dynamic simulation results demonstrate that the temperature/flow rate cascade control plus with simple temperature control can keep not only product purity but also the conversion of the reactant at their desired values in the face of the disturbance in reactant feed flow rate and feed composition.展开更多
Biodiesel is an attractive alternative to fossil fuels due to the energy and environmental concerns. In this paper, seven different multi –SO_(3)H functionalized ILs based on the low-cost less-substituted amines, whi...Biodiesel is an attractive alternative to fossil fuels due to the energy and environmental concerns. In this paper, seven different multi –SO_(3)H functionalized ILs based on the low-cost less-substituted amines, which contained massive sites for functionalization of sulfonic acid groups and further treatment of sulfonate-based anions, were prepared as catalysts with high acidity and desirable catalytic activity for the synthesis of biodiesel from the esterification of oleic acid with methanol. The physicochemical properties of these acidic ILs were characterized by a variety of analytical techniques such as FT-IR, EA, TGA, and the Br?nsted acidity was well determined by UV–vis. Among the ILs prepared, [EDA-PS][P-TSA] showed the highest catalytic activity for esterification due to its high acidity and appropriate miscibility with reactants, with an ultrahigh97.58% conversion of oleic acid under the optimum conditions(i.e. reaction time, 1.8 h;catalyst amount, 3 wt%;alcohol/acid molar ratio, 13:1,temperature 70℃) acquired from the Box–Behnken response surface methodology. With the novel strategy of multi –SO_(3) H modification on ILs,our catalyst had an approaching or even superior oleic acid conversion rate compared to other reported catalysts with considerably lower catalyst dosage and shorter reaction time. More importantly, it also exhibited high generality for converting various FFA feedstocks into biodiesel with considerable conversion within 93.59–94.33% under a rather lower catalyst dosage, which showed the valuable potential for converting low-cost oils into biodiesel from an economic and environmental perspective.展开更多
The ultra-deep desulfurization of oil needs to be solved urgently due to various problems,including environmental pollution and environmental protection requirements.Oxidative desulfurization(ODS)was considered to be ...The ultra-deep desulfurization of oil needs to be solved urgently due to various problems,including environmental pollution and environmental protection requirements.Oxidative desulfurization(ODS)was considered to be the most promising technology.The facile synthesis of highly efficient and stable HPW-based heterogeneous catalysts for oxidative desulfurization is still a challenging task.In this paper,pentamethylene hexamine(PEHA)and phosphotungstic acid(HPW)were combined by a simple one-step method to prepare a heterogeneous catalyst of PEHA-HPW for the production of ultra-deep desulfurization fuel oil.The composite material exhibited excellent catalytic activity and high recyclability,which could reach a 100% dibenzothiophene(DBT)removal rate in 30 min and be recycled at least 5 times.Experiments and DFT simulations were used to better examine the ODS mechanism of PEHA-HPW.It was proved that the rich amino groups on the surface of PEHA-HPW play a crucial role.This work provides a simple and feasible way for the manufacture of efficient HPW-based catalysts.展开更多
Dimethyl carbonate(DMC)is a crucial chemical raw material widely used in organic synthesis,lithiumion battery electrolytes,and various other fields.The current primary industrial process employs a conventional sodium ...Dimethyl carbonate(DMC)is a crucial chemical raw material widely used in organic synthesis,lithiumion battery electrolytes,and various other fields.The current primary industrial process employs a conventional sodium methoxide basic catalyst to produce DMC through the transesterification reaction between vinyl carbonate and methanol.However,the utilization of this catalyst presents several challenges during the process,including equipment corrosion,the generation of solid waste,susceptibility to deactivation,and complexities in separation and recovery.To address these limitations,a series of alkaline poly(ionic liquid)s,i.e.[DVBPIL][PHO],[DVCPIL][PHO],and[TBVPIL][PHO],with different crosslinking degrees and structures,were synthesized through the construction of cross-linked polymeric monomers and functionalization.These poly(ionic liquid)s exhibit cross-linked structures and controllable cationic and anionic characteristics.Research was conducted to investigate the effect of the cross-linking degree and structure on the catalytic performance of transesterification in synthesizing DMC.It was discovered that the appropriate cross-linking degree and structure of the[DVCPIL][PHO]catalyst resulted in a DMC yield of up to 80.6%.Furthermore,this catalyst material exhibited good stability,maintaining its catalytic activity after repeated use five times without significant changes.The results of this study demonstrate the potential for using alkaline poly(ionic liquid)s as a highly efficient and sustainable alternative to traditional catalysts for the transesterification synthesis of DMC.展开更多
The semiconductor manufacturing industry imposes stringent requirements on the metal ion content of photoresist resin monomers.Tris(2-carboxyethyl)isocyanurate(H_(3)tci),a critical raw material for photoresist resin m...The semiconductor manufacturing industry imposes stringent requirements on the metal ion content of photoresist resin monomers.Tris(2-carboxyethyl)isocyanurate(H_(3)tci),a critical raw material for photoresist resin monomers,inevitably incorporates metal ions during production.However,its inherent carboxyethyl groups form stable coordination complexes with Cr(Ⅲ),hindering the semiconductor-grade resin monomer production.To achieve the ultra-deep removal of Cr(Ⅲ)at ultra-trace concentrations,inspired by the hard–soft-acid–base theory,we systematically modulated the electron-rich sulfonic acid group on polymers via controlled sulfonation conditions to achieve a novel series of adsorption materials(St)with ultra-high Cr(Ⅲ)adsorption affinity.The adsorption–recrystallization process using 6 g of St-V-15 could reduce the Cr(Ⅲ)concentration in a solution containing 1 g of H_(3)tci from 840 ppb to 27.5 ppb.Furthermore,St-V-15 exhibited a maximum adsorption capacity of 145 mg g^(−1)calculated using the Langmuir model and a rapid initial adsorption rate of 82.92 mg g^(−1)min^(−1)at 333 K.Additionally,St-V-15 demonstrated exceptional selectivity for Cr(Ⅲ)over competing ions(e.g.,K(Ⅰ),Mg(Ⅱ),Na(Ⅰ)and Zn(Ⅱ))and maintained stable performance over at least 10 adsorption–desorption cycles.The superior performance originated from the chelation between Cr(Ⅲ)and the sites of O atoms(S–O and S=O)combined with the electrostatic interaction between deprotonated sulfonic acid groups and Cr(Ⅲ).These results position St-V-15 as a promising adsorption material for ultra-trace Cr(Ⅲ)removal in H_(3)tci,offering a cost-effective solution for semiconductor-grade resin monomer production for the very first time.展开更多
基金supported by the National Natural Science Foundation of China(22378065,22278077 and 22278076)the Key Program of Natural Science Foundation of Fujian Province of China(2022J02019).
文摘The production of high-purity propylene glycol monomethyl ether acetate(PMA)through the transesterification of propylene glycol monomethyl ether(PM)and methyl acetate(MeOAc)is traditionally catalyzed by sodium methoxide.However,the practical application of this method is significantly hindered by the inherent limitations of sodium methoxide,such as its high sensitivity to moisture and propensity for solid precipitation,which impede its effective use in continuous processes.This work proposed a continuous catalytic distillation(CD)process utilizing Amberlyst 15 cation exchange resin as the catalyst.A comprehensive series of reaction kinetic and CD experiments were conducted to evaluate the performance of the proposed process.The results demonstrate that under the optimal operating conditions,namely an ester-to-ether molar ratio of 6:1,a refluxratio of 5:1,a total feed rate of 0.92 g‧min^(-1),and an evaporation rate of 266.47 m^(3)‧m^(-2)‧h^(-1),the conversion rate of PM achieves 99.95%,and the PMA yield is 97.31%.Based on these findings,a process flowsheet for a continuous CD process tailored for the production of electronic-grade PMA is presented.This design incorporates light and heavy removal steps to ensure the production of PMA with a purity of 99.99%.Additionally,the process utilizes pressure swing distillation to recover MeOAc,thereby enhancing the overall efficiencyand sustainability of the production process.The proposed continuous CD process offers a highly efficient,cost-effective,and environmentally sustainable solution for the production of electronic-grade PMA.
基金supported by the National Natural Science Foundation of China(Grant No.22278077,22408209 and 22108040)National Key Research and Development Program of China(Grant No.2022YFB4101800)+2 种基金Key Program of Qingyuan Innovation Laboratory(Grant No.00221004)Research Program of Qingyuan Innovation Laboratory(Grant No.00523006)Natural Science Foundation of Fujian Province(Grant No.2022J02019,2024J011550).
文摘Dimethyl carbonate(DMC)is an important chemical raw material extensively used in organic synthesis,lithium-ion battery electrolytes,etc.The primary method for industrial synthesis of DMC involves transesterification between ethylene carbonate and MeOH but faces issues with difficult catalyst separation and low catalytic activity.Based on the synergistic catalytic activity of cation and anion,this study develops poly(ionic liquid)s of[N_(X)PIL][PHO]and[N_(3)PIL][Y]with varying alkaline sites and alkalinity levels.This is accomplished by constructing functional polymer monomers containing free radical polymerization sites and nitrogencontaining alkaline groups,and by polymerizing them with suitable crosslinking monomers in a specific ratio before exchanging the resulting polymers with different anions.Results show that doping with nitrogen-containing alkaline groups leads to enhanced basic functional sites while appropriate anions provide intensified alkalinity levels.The[N_(3)PIL][PHO]obtained exhibits superior catalytic activity in transesterification synthesis of DMC,with a yield of 91.43%and selectivity of 99.96%at a reaction time of 2 h.The study also investigates the impact of poly(ionic liquid)cationic structure and anion types,as well as their interactions,on catalytic performance.The findings reveal that the catalytic activity of poly(ionic liquid)is restricted by the interactions between cation and anion.Based on these findings,a possible reaction mechanism was proposed,providing theoretical support for the high-efficiency production of DMC.
基金supported by the National Natural Science Foundation of China(Grant No.22378065,22278077,22278076)。
文摘Designing efficient adsorbents for the deep removal of refractory dibenzothiophene(DBT)from fuel oil is vital for addressing environmental issues such as acid rain.Herein,zinc gluconate and urea-derived porous carbons SF-ZnNC-T(T represents the carbonization temperature)were synthesized without solvents.Through a temperature-controlled process of“melting the zinc gluconate and urea mixture,forming H-bonded polymers,and carbonizing the polymers,”the optimal carbon,SF-ZnNC-900,was obtained with a large surface area(2280 m^(2)g^(-1),highly dispersed Zn sites,and hierarchical pore structures.Consequently,SF-ZnNC-900 demonstrated significantly higher DBT adsorption capacity of43.2 mg S g^(-1),compared to just 4.3 mg S g^(-1)for the precursor.It also demonstrated good reusability,fast adsorption rate,and the ability for ultra-deep desulfurization.The superior DBT adsorption performance resulted from the evaporation of residual zinc species,which generated abundant mesopores that facilitated DBT transformation,as well as the formation of Zn-N_(x) sites that strengthened the host-vip interaction(ΔE=-1.466 e V).The solvent-free synthesized highly dispersed Zn-doped carbon shows great potential for producing sulfur-free fuel oil and for designing metal-loaded carbon adsorbents.
基金Supported by the National Natural Science Foundation of China(21306025,21576053)the International Science&Technology Cooperation Program of China(2013DFR90540)
文摘The solid acid SO_4^(2-)/TiO_2 was prepared by immersion method and applied for synthesis of propylene glycol methyl ether acetate(PMA) through esterification reaction of propylene glycol monomethyl ether(PM)and acetic acid(HAc). The optimal catalyst preparation condition was determined by orthogonal analysis of parameters in a five-factor and four-level test. The obtained solid acid catalysts were characterized in detail by means of X-ray powder diffraction, thermogravimetry, pyridine adsorbed IR analysis, scanning electron microscopy, and BET surface area method. Synthesis of PMA was studied in this paper through experimental investigation of reaction conditions such as temperature, molar ratio of reactants, catalyst dosage and agitation speed. Based on its possible reaction mechanism, a pseudo-homogeneous kinetic model was established and its activation energies E_a^+ and E_a^-,65.68 × 10~3J·mol^(-1) and 57.78 × 10~3J·mol^(-1), were estimated. To prepare shaped solid acid catalyst SO_4^(2-)/TiO_2, the shaping method of impregnation–shaping–impregnation was applied. The optimal molding formulation of solid acid catalyst, obtained from the orthogonal test, was found to be binder 7 wt%, reinforcing agent 20 wt%, pore forming material 2.5 wt%, and lubricant 4 wt%.The results of performance test of catalyst demonstrated that the shaped solid acid catalyst exhibited high activity and stability.
基金the National Natural Science Foundation of China(21878054)Project on the Integration of Industry and Education of Fujian Province(2018Y4008)+3 种基金Science and Technology Project of Fujian Educational Committee(JAT190051)Fuzhou University Testing Fund of precious apparatus(2020T008)Research Initiation Funding of Fuzhou University(GXRC-19051)the Award Program for Minjiang Scholar Professorship。
文摘A series of polymeric ionic liquids(PILs)used as effective heterogeneous catalysts for biodiesel production via esterification of free fatty acids(FFAs)were effectively prepared by the reaction of poly(ethylene imine)(PEI)polymers with different molecular weight and 1,3-propanesultone,followed by the further acidification with differential effective acids,i.e.H2SO4,CF3SO3H,CH3SO3H or p-toluenesulfonic acid(p-TSA).Ultrahigh acidity and catalytic performance were achieved and could be fine-tuned by simply adjusting the molecular weight of PEI and by further treatment of acids.Specifically,under the optimal conditions(i.e.reaction temperature was 70℃,reaction time was 2.0 h,catalyst dosage was 3.15%(mass),and alcohol/acid molar ratio was 14:1)acquired through the Box-BEHNKEN response surface methodology,a high oleic acid conversion of 98.42%could be obtained over the optimal PIL,PEI(70000)-PS-p-TSA.Additionally,our PILs also showed high generality for esterification of other FFAs,with general high conversion over 90%noted in each case even under much milder reaction conditions compared to other conventional catalysts.
基金the National Natural Science Foundation of China(Grant No.22108040 and 21878054)the Natural Science Foundation of Fujian Province(2020J05130)+1 种基金Science and Technology Project of Fujian Educational Committee(JAT190051)Research Project of Ningde Normal University(2019T03).
文摘Photocatalytic removal of tetracycline(TC)from the wastewater is of great value in the chemical and environmental engineering field.Here,we introduced a facile one-step method for the synthesis of BiOBr/Bi2WO6 heterojunctions by using cheap CTAB as the Br source.We showed the possibility of our method to fine-tune the content of BiOBr in the produced BiOBr/Bi2WO6 by simply changing the dosage of cetyltrimethylammonium bromide(CTAB),providing a platform for the delicate tuning of the visiblelight absorbance ability of the composites.With a suitable heterojunction structure of BiOBr/Bi2WO6-0.2,it exhibited an ultrarapid photocatalytic activity towards TC(20 mgL^(-1)),with a competitive removal efficiency of 88.1%within 60 min and an ultrahigh removal rate of 0.0349 min^(-1).It could also be robustly recycled for at least 5 cycles with slight removal efficiency loss.We demonstrated that this exciting photocatalytic performance was due to the highly decreased recombination of photoinduced electrons and holes on our composites by constructing this heterojunction structure,and the resultingOH andO^(-)_(2)contributed to the effective degradation of TC to CO_(2).
基金Supported by the National Natural Science Foundation of China(21306025,21576053)the International Science&Technology Cooperation Program of China(2013DFR90540)
文摘Dimethyl carbonate is an environmentally benign and biodegradable chemical.Based on integration of reactive distillation and pressure-swing distillation technologies,a novel process for synthesis of dimethyl carbonate through transesterification with propylene carbonate and methanol has been developed by Huang et al.In this work,the optimization of this process was performed by minimizing the total TAC.The results show that the optimal design flowsheet can save energy consumption by 18.6% with the propylene carbonate conversion of 99.9%.Then,an effective plant-wide control structure for the process was developed.Dynamic simulation results demonstrate that the temperature/flow rate cascade control plus with simple temperature control can keep not only product purity but also the conversion of the reactant at their desired values in the face of the disturbance in reactant feed flow rate and feed composition.
基金supporting by National Natural Science Foundation of China(Grant No.21878054)Project on the Integration of Industry and Education of Fujian Province(Project No.2018Y4008)。
文摘Biodiesel is an attractive alternative to fossil fuels due to the energy and environmental concerns. In this paper, seven different multi –SO_(3)H functionalized ILs based on the low-cost less-substituted amines, which contained massive sites for functionalization of sulfonic acid groups and further treatment of sulfonate-based anions, were prepared as catalysts with high acidity and desirable catalytic activity for the synthesis of biodiesel from the esterification of oleic acid with methanol. The physicochemical properties of these acidic ILs were characterized by a variety of analytical techniques such as FT-IR, EA, TGA, and the Br?nsted acidity was well determined by UV–vis. Among the ILs prepared, [EDA-PS][P-TSA] showed the highest catalytic activity for esterification due to its high acidity and appropriate miscibility with reactants, with an ultrahigh97.58% conversion of oleic acid under the optimum conditions(i.e. reaction time, 1.8 h;catalyst amount, 3 wt%;alcohol/acid molar ratio, 13:1,temperature 70℃) acquired from the Box–Behnken response surface methodology. With the novel strategy of multi –SO_(3) H modification on ILs,our catalyst had an approaching or even superior oleic acid conversion rate compared to other reported catalysts with considerably lower catalyst dosage and shorter reaction time. More importantly, it also exhibited high generality for converting various FFA feedstocks into biodiesel with considerable conversion within 93.59–94.33% under a rather lower catalyst dosage, which showed the valuable potential for converting low-cost oils into biodiesel from an economic and environmental perspective.
基金supported by the National Natural Science Foundation of China(22378065,22278077)the Fujian Province Department of Science&Technology,China(2019YZ017001)。
文摘The ultra-deep desulfurization of oil needs to be solved urgently due to various problems,including environmental pollution and environmental protection requirements.Oxidative desulfurization(ODS)was considered to be the most promising technology.The facile synthesis of highly efficient and stable HPW-based heterogeneous catalysts for oxidative desulfurization is still a challenging task.In this paper,pentamethylene hexamine(PEHA)and phosphotungstic acid(HPW)were combined by a simple one-step method to prepare a heterogeneous catalyst of PEHA-HPW for the production of ultra-deep desulfurization fuel oil.The composite material exhibited excellent catalytic activity and high recyclability,which could reach a 100% dibenzothiophene(DBT)removal rate in 30 min and be recycled at least 5 times.Experiments and DFT simulations were used to better examine the ODS mechanism of PEHA-HPW.It was proved that the rich amino groups on the surface of PEHA-HPW play a crucial role.This work provides a simple and feasible way for the manufacture of efficient HPW-based catalysts.
基金supported by the National Key Research and Development Program of China(2022YFB4101800)National Natural Science Foundation of China(22278077,22108040)+2 种基金Key Program of Qingyuan Innovation Laboratory(00221004)Research Program of Qingyuan Innovation Laboratory(00523006)Natural Science Foundation of Fujian Province(2022J02019)。
文摘Dimethyl carbonate(DMC)is a crucial chemical raw material widely used in organic synthesis,lithiumion battery electrolytes,and various other fields.The current primary industrial process employs a conventional sodium methoxide basic catalyst to produce DMC through the transesterification reaction between vinyl carbonate and methanol.However,the utilization of this catalyst presents several challenges during the process,including equipment corrosion,the generation of solid waste,susceptibility to deactivation,and complexities in separation and recovery.To address these limitations,a series of alkaline poly(ionic liquid)s,i.e.[DVBPIL][PHO],[DVCPIL][PHO],and[TBVPIL][PHO],with different crosslinking degrees and structures,were synthesized through the construction of cross-linked polymeric monomers and functionalization.These poly(ionic liquid)s exhibit cross-linked structures and controllable cationic and anionic characteristics.Research was conducted to investigate the effect of the cross-linking degree and structure on the catalytic performance of transesterification in synthesizing DMC.It was discovered that the appropriate cross-linking degree and structure of the[DVCPIL][PHO]catalyst resulted in a DMC yield of up to 80.6%.Furthermore,this catalyst material exhibited good stability,maintaining its catalytic activity after repeated use five times without significant changes.The results of this study demonstrate the potential for using alkaline poly(ionic liquid)s as a highly efficient and sustainable alternative to traditional catalysts for the transesterification synthesis of DMC.
基金supported by the National Natural Science Foundation of China(Grant No.22478077,22278077).
文摘The semiconductor manufacturing industry imposes stringent requirements on the metal ion content of photoresist resin monomers.Tris(2-carboxyethyl)isocyanurate(H_(3)tci),a critical raw material for photoresist resin monomers,inevitably incorporates metal ions during production.However,its inherent carboxyethyl groups form stable coordination complexes with Cr(Ⅲ),hindering the semiconductor-grade resin monomer production.To achieve the ultra-deep removal of Cr(Ⅲ)at ultra-trace concentrations,inspired by the hard–soft-acid–base theory,we systematically modulated the electron-rich sulfonic acid group on polymers via controlled sulfonation conditions to achieve a novel series of adsorption materials(St)with ultra-high Cr(Ⅲ)adsorption affinity.The adsorption–recrystallization process using 6 g of St-V-15 could reduce the Cr(Ⅲ)concentration in a solution containing 1 g of H_(3)tci from 840 ppb to 27.5 ppb.Furthermore,St-V-15 exhibited a maximum adsorption capacity of 145 mg g^(−1)calculated using the Langmuir model and a rapid initial adsorption rate of 82.92 mg g^(−1)min^(−1)at 333 K.Additionally,St-V-15 demonstrated exceptional selectivity for Cr(Ⅲ)over competing ions(e.g.,K(Ⅰ),Mg(Ⅱ),Na(Ⅰ)and Zn(Ⅱ))and maintained stable performance over at least 10 adsorption–desorption cycles.The superior performance originated from the chelation between Cr(Ⅲ)and the sites of O atoms(S–O and S=O)combined with the electrostatic interaction between deprotonated sulfonic acid groups and Cr(Ⅲ).These results position St-V-15 as a promising adsorption material for ultra-trace Cr(Ⅲ)removal in H_(3)tci,offering a cost-effective solution for semiconductor-grade resin monomer production for the very first time.
