The porous alumina ceramics with lamellar structure were fabricated successfully by freeze casting. The viscosities of alumina slurries, pore structures, porosities and mechanical properties of the sintered ceramics w...The porous alumina ceramics with lamellar structure were fabricated successfully by freeze casting. The viscosities of alumina slurries, pore structures, porosities and mechanical properties of the sintered ceramics were investigated by introducing both types of alcohols as water solidification modifier into the initial slurries, such as ethanol and 1-propanol. With the addition of ethanol or 1-propanol, the viscosities of slurries increased and porosities of sintered ceramics decreased. The compressive strengths of the sintered porous alumina ceramics were improved due to a good connectivity between lamellae with the addition of both types of alcohols. The lowest porosities of 68.52% and 73.72% and highest compressive strengths of 18.2 MPa and 15.0 MPa were obtained by the addition of 30% ethanol in mass fraction and 1-propanol, respectively.展开更多
[Objective] The aim was to provide scientific basis for development and utilization of Pinus elliottii Engelm resources.[Method] The extraction process of shikimic acid in Pinus elliottii Engelm was studied,and the co...[Objective] The aim was to provide scientific basis for development and utilization of Pinus elliottii Engelm resources.[Method] The extraction process of shikimic acid in Pinus elliottii Engelm was studied,and the content of shikimic acid was determined by HPLC.The HPLC conditions were as follows;Alltima NH2 (5 μm,4.6 mm × 150 mm) column separation;the mobile phase was acetonitrile-2%H3PO4 (90:10);the flowing velocity was 1 ml/min;test wavelength was 213 nm,the width of belt was 16 nm;reference wavelength was 300 nm,the width of belt was 80 nm.[Result] By the single factor and orthogonal tests,the optimum conditions were found as follows:ethanol concentration 60%,extraction temperature 75 ℃,solid-liquid ratio 1:25,extraction time 2.5 h.The extraction rate of shikimic acid was 1.49%.[Conclusion] Shikimic acid in Pinus elliottii Engelm could be used as a new resource to develop and utilize.展开更多
In order to explore the advantages of self-heat recuperative distillation(SHRD) process, the design and control of the SHRD process was studied for the separation of n-butanol and iso-butanol mixtures. The economic su...In order to explore the advantages of self-heat recuperative distillation(SHRD) process, the design and control of the SHRD process was studied for the separation of n-butanol and iso-butanol mixtures. The economic superiority of SHRD process is presented when a comparison on the total annual cost(TAC) of the conventional distillation process, the vapor recompression distillation process and the SHRD process was made. For the SHRD process, 37.74% and 11.35% savings of TAC can be achieved as compared to the conventional distillation process and vapor recompression distillation process, respectively. The dynamic characteristics of this promising SHRD sequence had been studied, and the dynamic responses demonstrated that 10% changes in both feed flow rate and feed composition can be well handled by the control strategy with dual-temperature control. It is proven that the SHRD system not only can provide economical savings but also can operate normally with good controllability.展开更多
The solid-liquid equilibrium of benzoic acid derivatives in 1-octanol was first determined in this article. Using a laser monitoring observation technique, the solubility data of o-amino-benzoic acid, p-amino-benzoic ...The solid-liquid equilibrium of benzoic acid derivatives in 1-octanol was first determined in this article. Using a laser monitoring observation technique, the solubility data of o-amino-benzoic acid, p-amino-benzoic acid,o-chloro-benzoic acid, and m-nitro-benzoic acid in 1-octanol were measured by the polythermal method in the temperature range of 20-50℃. The experimental data were regressed with the. Wilson equation and the λH equation. The experimental results showed that the solubility of the four chemicals in 1-octanol increased significantly with temperature. The results indicate that the molecular structure and interactions affect the solubility significantly.The solubility order of the benzoic acid derivatives is as follows: m-nitro-benzoic acid〉o-chloro-benzoic acid〉 o-amino-benzoic acid〉p-amino-benzoic acid. Both the Wilson equation and λH equation are in good agreement with the experimental data.展开更多
Zr‐Al mixed oxide supported Pt catalysts with different Zr/Al mole ratios(2.5%Pt/ZrxAl(1–x)Oy) were synthesized by an impregnation method and used for the selective hydrogenolysis of glycerol to n‐propanol in a...Zr‐Al mixed oxide supported Pt catalysts with different Zr/Al mole ratios(2.5%Pt/ZrxAl(1–x)Oy) were synthesized by an impregnation method and used for the selective hydrogenolysis of glycerol to n‐propanol in an autoclave reactor. The catalysts were fully characterized by X‐ray powder diffrac‐tion, Brunauer‐Emmett‐Teller surface area analysis, CO chemisorption, H2 temperature‐ pro‐grammed reduction, pyridine‐infrared spectroscopy, and NH3‐temperature‐programmed desorp‐tion. The results revealed that the Zr/Al ratio on the support significantly affected the size of the platinum particles and the properties of the acid sites on the catalysts. The catalytic performance was well correlated with the acidic properties of the catalyst; specifically, more acid sites contrib‐uted to the conversion and strong acid sites with a specific intensity contributed to the deep dehy‐dration of glycerol to form n‐propanol. Among the tested catalysts, 2.5 wt% Pt/Zr(0.7)Al(0.3)Oy exhibited excellent selectivity for n‐propanol with 81.2% glycerol conversion at 240 °C and 6.0 MPa H2 pres‐sure when 10% aqueous glycerol solution was used as the substrate. In addition, the effect of vari‐ous reaction parameters, such as H2 content, reaction temperature, reaction time, and number of experimental cycles were studied to determine the optimized reaction conditions and to evaluate the stability of the catalyst.展开更多
A new reactive and extractive distillation process with ionic liquids as entrainer and catalyst (RED-IL)was proposed to produce methanol and n-butyl acetate by transesterification reaction of methyl acetate with n-b...A new reactive and extractive distillation process with ionic liquids as entrainer and catalyst (RED-IL)was proposed to produce methanol and n-butyl acetate by transesterification reaction of methyl acetate with n-butanol. The RED-IL process was simulated via a rigorous model, and high purity products of methanol and n-butyl acetate can be obtained in such a process. The effects of reflux ratio, feed mode, holdup, feed location, entrainer ratio and catalyst concentration on RED-IL process were investigated. The conversion of methyl acetate and purities of products increase with the holdup in column, entrainer ratio and catalyst content. An optimal reflux ratio exists in RED-IL process. Comparing to the mixed-feed mode, the segregated-feed mode is more effective, in which the optimal feed locations of reactants exist.展开更多
Experiments were carried out to investigate the influences of cation from electrolytes and acidity/alkalinity on the phase behavior of sodium dodecyl sulfate-n-butanol-organics-water (with electrolytes) microemulsio...Experiments were carried out to investigate the influences of cation from electrolytes and acidity/alkalinity on the phase behavior of sodium dodecyl sulfate-n-butanol-organics-water (with electrolytes) microemulsion sys-tem. The organics used is commercial kerosene. The volume ratio of water to organics is 1︰1. The results show that the type and valence of electrolyte cations are important factors influencing the microemulsion behavior. Biva-lent Ca2+is more effective than monovalent K+and Na+for the formation of Winsor type III and II microemulsion. For electrolytes with the same monovalent cation Na+, i.e. NaCl and Na2CO3, anions in the electrolyte have some effect. Bivalent anion 23CO - leads to a lower activity of cation Na+than monovalent anion Cl-. NaOH (or KOH) behaves similar with NaCl (or KCl). When HCl is used as electrolyte, its acidity plays an important role. Phase in-version of microemulsion from type III (or II) to type I is observed through precipitation of Ca2+using Na2CO3, neutralization of HCl by NaOH, and addition of water to the system, which releases the oil from the microemulsion.展开更多
To explore the feasibility of extracting aromatic acid products from oxidizing coal, two aromatic acids, trimellitic and [1,1′-biphenyl]-2,2′-dicarboxylic acid, were selected as the solutes, and the extraction equil...To explore the feasibility of extracting aromatic acid products from oxidizing coal, two aromatic acids, trimellitic and [1,1′-biphenyl]-2,2′-dicarboxylic acid, were selected as the solutes, and the extraction equilibrium of the acids were studied with 1-octanol, 50% tributyl phosphate (TBP) in kerosene, and 10% trialkylphosphine oxide (TRPO) in kerosene. The results showed that the degree of extraction of [1,1′-biphenyl]-2,2′-dicarboxylic acid was larger than that of trimellitic acid for all of the solvent, and the extraction capacity with TRPO is more effective than the one with TBP. The extraction behavior of aromatic polyacid is different from that of carboxylic acid, and the reactive extraction function of aromatic acids with TBP and TRPO is not as effective as that of carboxylic acid. 1-octanol could be used to remove [1,1′-biphenyl]-2,2′-dicarboxylic acid from the mixture of trimellitic acid and [1,1′-biphenyl]-2,2′-dicarboxylic acid. Because the weak hydrogen bond association exists between -OH in 1-octanol and -COOH in aromatic acid, the extractive selectivity of [ 1, 1′-biphenyl]-2,2′-dicarboxylic to trimellitic acid depends on the stoichiometric ratio.展开更多
A novel method named two-level group contribution (GC-K) method for the estimation of octanol-water partition coefficient (Kow) of chloride hydrocarbon is presented. The equation includes only normal boiling point...A novel method named two-level group contribution (GC-K) method for the estimation of octanol-water partition coefficient (Kow) of chloride hydrocarbon is presented. The equation includes only normal boiling points and molecular weight of compounds. Group contribution parameters of 12 first-level groups and 7 second-level groups for Kow are obtained by correlating experimental data of three types including 57 compounds. By comparing the estimation results of the first-level with that of the two-level groups, it was observed that the latter is better with the addition of the modification of proximity effects. When compared with Marrero's three-level group contribution approach and atom-fragment contribution method (AFC), the accuracy of the average relative error of GC-K by first-level groups is 7.20% and is preferred to other methods.展开更多
As a new kind of2D nanomaterials, graphene oxide (GO) with 2-4 layers was fabricated rio a modified Hummers method and used for the preparation ofpervaporation (PV) membranes. Such GO membranes were prepared via a...As a new kind of2D nanomaterials, graphene oxide (GO) with 2-4 layers was fabricated rio a modified Hummers method and used for the preparation ofpervaporation (PV) membranes. Such GO membranes were prepared via a facile vacuum-assisted method on anodic aluminium oxide disks and applied for the dehydration of butanol. To obtain GO membranes with high performance, effects of pre-treatments, including high-speed centrifugal treat- ment of GO dispersion and thermal treatment of GO membranes, were investigated. In addition, effects of operation conditions on the performance of GO membranes in the PV process and the stability of GO membranes were also studied. It is of benefit to improve the selectivity of GO membrane by pre-treatment that centrifuges the GO dispersion with 10000 r· min^- 1 for 40 min, which could purify the GO dispersion by removing the large size GO sheets. As prepared GO membrane showed high separation performance for the butanol/water system. The separation factor was 230, and the permeability was as high as 3.1 kg·m^- 2·h^-1 when the PV temperature was 50 ℃ and the water content in feed was 10% (by mass). Meanwhile, the membrane still showed good stability for the dehydration of butanol after running for 1800 min in the PV process. GO membranes are suitable candidates for butanol dehydration via PV process.展开更多
The esterification reactions of lactic acid with isobutanol and n-butanol have been studied in the presence of acid ion-exchange resin Weblyst D009. The influences of catalyst loading, stirrer speed, catalyst particle...The esterification reactions of lactic acid with isobutanol and n-butanol have been studied in the presence of acid ion-exchange resin Weblyst D009. The influences of catalyst loading, stirrer speed, catalyst particle size, initial reactant molar ratio and temperature on the reaction rate have been examined. Experimental kinetic data were correlated by using the pseudo-homogeneous, Langnluir-Hinshelwood and Eley-Rideal models. Nonideality of the liquid phase was taken into account by using activities instead of molar fractions. The activity coefficients were calculated according to the group contribution method UNIFAC. Provided that the nonideality of the liquid is taken into account, the esterification kinetics of lactic acid with isobutanol and n-butanol catalyzed by the acid ion-exchange resin can be described using all threemodels with reasonable errors.展开更多
The separation of ternary mixture of butanol, butyl acetate, and methyl isobutyl ketone(MIBK) was initially analyzed by the residual curve. In this process, MIBK was chosen as the azeotropic agent during the first ste...The separation of ternary mixture of butanol, butyl acetate, and methyl isobutyl ketone(MIBK) was initially analyzed by the residual curve. In this process, MIBK was chosen as the azeotropic agent during the first step of separation. The optimum mass ratio of extra MIBK was 1.6 in the modified feed stream according to the residual curve. Thus on this condition the top product was butanol-MIBK azeotrope while the bottom product was butyl acetate in the preliminary separation of the mixture. Then the butanol and MIBK azeotrope was separated by the double effect pressureswing distillation with the low pressure column performing at 30 kPa and the atmospheric pressure column at 101 kPa. The optimal operating conditions were then obtained by using Aspen Plus to simulate and optimize the process. The results showed that the mass purities of butanol, butyl acetate, and MIBK were all more than 99% and reached the design requirements. Additionally, compared with the traditional distillation with outside heating, the double effect pressure swing distillation saved the reboiler duty by 48.6% and the condenser duty by 44.6%.展开更多
The forming mechanism of microemulsion of sodium dodecyl sulfonate, alcohols,water and isooctane was studied, with particular emphasis on the effect of molecular weight andconcentration of alcohols. Phase diagram of t...The forming mechanism of microemulsion of sodium dodecyl sulfonate, alcohols,water and isooctane was studied, with particular emphasis on the effect of molecular weight andconcentration of alcohols. Phase diagram of the four components, alcohol, sodium dodecyl sulfonate,water and isooctane, was used as a means of study, through which the microemulsion regions weredetermined. Phase diagram of sodium dodecyl sulfonate/n-pentanol/isooctane/water system at κ_m = 2(κ_m = W_(n-pentanol)/W_(SDS)) is presented. The variation of conductivities of differentmicroemulsion samples with water was measured. From the conductivities we investigated a change instructure from water droplets in oil (W/O) at low water content to liquid crystal at intermediatewater content and a stricture of oil droplets in water (O/W) at high water content.展开更多
In order to investigate the effect of butanol on quartz flotation when N-dodecyl ethylenediamine(ND)was used as collector, single mineral flotation and artificial mixed mineral(hematite and quartz were mixed at a mass...In order to investigate the effect of butanol on quartz flotation when N-dodecyl ethylenediamine(ND)was used as collector, single mineral flotation and artificial mixed mineral(hematite and quartz were mixed at a mass ratio of 3:2) separation were conducted in the laboratory. Experimental results indicated that addition of butanol could improve the collecting performance of ND on quartz and enhance the floatability of quartz. Best flotation recovery of quartz was obtained when butanol was mixed with ND at a mass ratio of 1:1. Moreover, the molecular structure of alcohols had a significant effect on mineral recovery. Best separation efficiency could be obtained when tert-butanol was added as it had the largest cross-sectional area. Zeta potential measurements indicated that alcohols could strengthen electrostatic adsorption between quartz and collector. Molecular dynamic simulations revealed that co-adsorption of alcohols along with ND had taken place on the quartz surface, and ND/tert-butyl combinations were more easily absorbed on the quartz surface.展开更多
Densities(ρ) and dynamic viscosities(η) for three binary mixtures of n-decane with 1-pentanol,1-hexanol and1-heptanol are presented at temperatures from 293.15 to 363.15 K and atmospheric pressure over the entire co...Densities(ρ) and dynamic viscosities(η) for three binary mixtures of n-decane with 1-pentanol,1-hexanol and1-heptanol are presented at temperatures from 293.15 to 363.15 K and atmospheric pressure over the entire composition range.The density and viscosity are measured using a vibrating tube densimeter and a cylindrical Couette type rotating viscometer,respectively.Excess molar volumes(V^E),viscosity deviations(△η) and excess Gibbs energy of activation of viscous flow(△G^(*E)) are calculated from the experimental measurements.Intermolecular and structural interactions are indicated by the sign and magnitude of these properties.Partial molar volumes and infinity dilution molar partial volumes are also calculated for each binary system.These results are correlated using Redlich-Kister type equations.展开更多
The distributions of nicotinic acid (NA) between water and trialkylamine (N235) dissolved in n-octanol was studied. The complexes of N235 and NA were investigated by Fourier transformation infrared spectrometry to ded...The distributions of nicotinic acid (NA) between water and trialkylamine (N235) dissolved in n-octanol was studied. The complexes of N235 and NA were investigated by Fourier transformation infrared spectrometry to deduce the reaction mechanism. It was found that N235/n-octanol was an efficient extractant for extracting nicotinic acid. The favorable operation conditions were equilibrium aqueous pH 4.2 to 5.5 and initial N235 concentration<0.42 mol·L-1 . The reaction processes included the reaction between neutral N235 and neutral NA and the reaction between protonated N235 and anionic NA. Based on the mass action law and some assumptions, an expression for distribution coefficient D was proposed. The apparent extraction equilibrium constants were calculated by fitting the experimental data and the results were satisfactory.展开更多
Based on a previous investigation,a simulation model was used for optimization of coproduction of ethyl acetate and n-butyl acetate by reactive distillation.An experimental setup was established to verify the simulate...Based on a previous investigation,a simulation model was used for optimization of coproduction of ethyl acetate and n-butyl acetate by reactive distillation.An experimental setup was established to verify the simulated results.The effects of various operating variables,such as ethanol feed location,acetic acid feed location,feed stage of reaction mixture of acetic acid and n-butanol,reflux ratio of ethyl acetate reactive distillation column,and distillate to feed ratio of n-butyl acetate column,on the ethanol/n-butanol conversions,ethyl acetate/n-butyl acetate purity,and energy consumption were investigated.The optimal results in the simulation study are as follows:ethanol feed location,15th stage;acetic acid feed location,eighth stage;feed location of reaction mixture of acetic acid and n-butanol,eighth stage;reflux ratio of ethyl acetate reactive distillation column,2.0;and distillate to feed ratio of n-butyl acetate,0.6.展开更多
It is already well known that availability of petroleum oil, as a world energy source, is running low. Much work has been done by experts to produce renewable energy, especially using vegetable oil as a raw material. ...It is already well known that availability of petroleum oil, as a world energy source, is running low. Much work has been done by experts to produce renewable energy, especially using vegetable oil as a raw material. Accordingly, this paper presents preparation and activity test of Cu catalyst using coconut shell activated carbon (AC) as a support, for conversion of n-pentanol and n-butanol to their alkenes as the first step of conversion of ethanol to biogasoline. This conversion is interesting due to any agriculture product containing sugar or starch can be converted to ethanol. Activated carbon was used as a catalyst support because this material is inert; hence, it would not yield unexpected side product, and pollution of environment with the used catalyst can be prevented because the used catalytic metal can easily be recovered. Results of the work showed that coconut shell carbon contained some metals, which disturbed in preparation catalyst by cation exchange process. Washing the carbon with ammonium acetate or HCI solution could reduce the metals content more compared to using water, with optimum concentration for ammonium acetate solution was 1.25 M. Application of Cu/AC in converting n-pentanol and n-butanol, based on qualitative analysis to the products using GLC, GC-MS, and FTIR, when n-pentanol and nitrogen gas were flowed into a reactor filled with Cu/AC catalyst, it could be converted to n-pentene with 200 ℃ as the optimal temperature. While when n-butanol and nitrogen gas were flowed into a reactor filled with more Cu/AC catalyst, the product was supposed to contain its aldehyde and butyl vinyl ether.展开更多
Neuromuscular junction is the main target for snakebites, which venoms act depending on the snake genus for paralyzing the prey (neurotoxicity) or for facilitating the digestion processes of the victim (myotoxicity...Neuromuscular junction is the main target for snakebites, which venoms act depending on the snake genus for paralyzing the prey (neurotoxicity) or for facilitating the digestion processes of the victim (myotoxicity), and also as a defense mechanism against predators. In the present study, a mouse neuromuscular apparatus was used for testing the hexane fraction of Casearia gossypiosperma plant, that showed the better antiophidian ability than dichloromethane, ethyl acetate and methanol fractions, against the irreversible paralysis induced by two, Bothrops jararacussu (Bjssu, 40 μg/mL) and Crotalus durissus terrificus (Cdt, 10 μg/mL) snake venoms. All fractions were obtained by liquid-liquid partition from the C. gossypiosperma hydroalcoholic lyophilized extract. The preliminary chromatographic profile of this plant showed phenols and flavonols as active constituents, whereas hexane fraction expressed mainly 13-sitosterol and quercetin. In spite of hexane fraction protection (≌95% and 48% against Bjssu and Cdt, respectively), isolately, only quercetin protected against the blockade-induced by Bjssu venom (65.5%). This study showed that hexane fraction acts against these snake venoms by a synergistic phytocomplex mechanism.展开更多
基金Projects(20110162130003,20110162110044)supported by the PhD Programs Foundation of Ministry of Education of ChinaProjects(51172288,51072235)supported by the National Natural Science Foundation of ChinaProject(11JJ1008)supported by Hunan Provincial Natural Science Foundation of China
文摘The porous alumina ceramics with lamellar structure were fabricated successfully by freeze casting. The viscosities of alumina slurries, pore structures, porosities and mechanical properties of the sintered ceramics were investigated by introducing both types of alcohols as water solidification modifier into the initial slurries, such as ethanol and 1-propanol. With the addition of ethanol or 1-propanol, the viscosities of slurries increased and porosities of sintered ceramics decreased. The compressive strengths of the sintered porous alumina ceramics were improved due to a good connectivity between lamellae with the addition of both types of alcohols. The lowest porosities of 68.52% and 73.72% and highest compressive strengths of 18.2 MPa and 15.0 MPa were obtained by the addition of 30% ethanol in mass fraction and 1-propanol, respectively.
基金Supported by National Natural Science Foundation of China(30560119)Supported by Natural Science Foundation of Guangxi(0991030)+3 种基金Innovational Plan Project for Guangxi Postgraduate Ed-ucation(2008105930817M46)Project of Science Research Project of Guangxi Education Department([2006]26),Project of Science Research Project of Guangxi Education Department(200708LX180)Scientific Researc-hing fund project of Guangxi University(X081020)Fund Project for Guangxi Young People(0832008)~~
文摘[Objective] The aim was to provide scientific basis for development and utilization of Pinus elliottii Engelm resources.[Method] The extraction process of shikimic acid in Pinus elliottii Engelm was studied,and the content of shikimic acid was determined by HPLC.The HPLC conditions were as follows;Alltima NH2 (5 μm,4.6 mm × 150 mm) column separation;the mobile phase was acetonitrile-2%H3PO4 (90:10);the flowing velocity was 1 ml/min;test wavelength was 213 nm,the width of belt was 16 nm;reference wavelength was 300 nm,the width of belt was 80 nm.[Result] By the single factor and orthogonal tests,the optimum conditions were found as follows:ethanol concentration 60%,extraction temperature 75 ℃,solid-liquid ratio 1:25,extraction time 2.5 h.The extraction rate of shikimic acid was 1.49%.[Conclusion] Shikimic acid in Pinus elliottii Engelm could be used as a new resource to develop and utilize.
基金Financial supports from the National Natural Science Foundation of China(Grant:21276279 and Grant:21476261)the Fundamental Research Funds for the Central Universities(No.14CX05030ANo.15CX06042A)
文摘In order to explore the advantages of self-heat recuperative distillation(SHRD) process, the design and control of the SHRD process was studied for the separation of n-butanol and iso-butanol mixtures. The economic superiority of SHRD process is presented when a comparison on the total annual cost(TAC) of the conventional distillation process, the vapor recompression distillation process and the SHRD process was made. For the SHRD process, 37.74% and 11.35% savings of TAC can be achieved as compared to the conventional distillation process and vapor recompression distillation process, respectively. The dynamic characteristics of this promising SHRD sequence had been studied, and the dynamic responses demonstrated that 10% changes in both feed flow rate and feed composition can be well handled by the control strategy with dual-temperature control. It is proven that the SHRD system not only can provide economical savings but also can operate normally with good controllability.
基金Supported by the National Natural Science Foundation of China (No.20676101) and the Natural Science Foundation of Tianjin University of Science & Technology (No.20050207).
文摘The solid-liquid equilibrium of benzoic acid derivatives in 1-octanol was first determined in this article. Using a laser monitoring observation technique, the solubility data of o-amino-benzoic acid, p-amino-benzoic acid,o-chloro-benzoic acid, and m-nitro-benzoic acid in 1-octanol were measured by the polythermal method in the temperature range of 20-50℃. The experimental data were regressed with the. Wilson equation and the λH equation. The experimental results showed that the solubility of the four chemicals in 1-octanol increased significantly with temperature. The results indicate that the molecular structure and interactions affect the solubility significantly.The solubility order of the benzoic acid derivatives is as follows: m-nitro-benzoic acid〉o-chloro-benzoic acid〉 o-amino-benzoic acid〉p-amino-benzoic acid. Both the Wilson equation and λH equation are in good agreement with the experimental data.
基金supported by the National Natural Science Foundation of China (21573031, 21373038)the Program for Excellent Talents in Dalian City (2016RD09)the Doctoral Scientific Research Foundation of Liao Ning Province (20170520395)~~
文摘Zr‐Al mixed oxide supported Pt catalysts with different Zr/Al mole ratios(2.5%Pt/ZrxAl(1–x)Oy) were synthesized by an impregnation method and used for the selective hydrogenolysis of glycerol to n‐propanol in an autoclave reactor. The catalysts were fully characterized by X‐ray powder diffrac‐tion, Brunauer‐Emmett‐Teller surface area analysis, CO chemisorption, H2 temperature‐ pro‐grammed reduction, pyridine‐infrared spectroscopy, and NH3‐temperature‐programmed desorp‐tion. The results revealed that the Zr/Al ratio on the support significantly affected the size of the platinum particles and the properties of the acid sites on the catalysts. The catalytic performance was well correlated with the acidic properties of the catalyst; specifically, more acid sites contrib‐uted to the conversion and strong acid sites with a specific intensity contributed to the deep dehy‐dration of glycerol to form n‐propanol. Among the tested catalysts, 2.5 wt% Pt/Zr(0.7)Al(0.3)Oy exhibited excellent selectivity for n‐propanol with 81.2% glycerol conversion at 240 °C and 6.0 MPa H2 pres‐sure when 10% aqueous glycerol solution was used as the substrate. In addition, the effect of vari‐ous reaction parameters, such as H2 content, reaction temperature, reaction time, and number of experimental cycles were studied to determine the optimized reaction conditions and to evaluate the stability of the catalyst.
基金Supported by the Innovation Fund of Tianjin University
文摘A new reactive and extractive distillation process with ionic liquids as entrainer and catalyst (RED-IL)was proposed to produce methanol and n-butyl acetate by transesterification reaction of methyl acetate with n-butanol. The RED-IL process was simulated via a rigorous model, and high purity products of methanol and n-butyl acetate can be obtained in such a process. The effects of reflux ratio, feed mode, holdup, feed location, entrainer ratio and catalyst concentration on RED-IL process were investigated. The conversion of methyl acetate and purities of products increase with the holdup in column, entrainer ratio and catalyst content. An optimal reflux ratio exists in RED-IL process. Comparing to the mixed-feed mode, the segregated-feed mode is more effective, in which the optimal feed locations of reactants exist.
基金Supported by the National Natural Science Foundation of China(21106187)Promotive Research Funds for Excellent Young and Middle-aged Scientists of Shandong Province(BS2011NJ021)+1 种基金the Fundamental Research Funds for the Central Universities(11CX05016A)the Graduate Innovation Project of CUP 2012(CX-1214)
文摘Experiments were carried out to investigate the influences of cation from electrolytes and acidity/alkalinity on the phase behavior of sodium dodecyl sulfate-n-butanol-organics-water (with electrolytes) microemulsion sys-tem. The organics used is commercial kerosene. The volume ratio of water to organics is 1︰1. The results show that the type and valence of electrolyte cations are important factors influencing the microemulsion behavior. Biva-lent Ca2+is more effective than monovalent K+and Na+for the formation of Winsor type III and II microemulsion. For electrolytes with the same monovalent cation Na+, i.e. NaCl and Na2CO3, anions in the electrolyte have some effect. Bivalent anion 23CO - leads to a lower activity of cation Na+than monovalent anion Cl-. NaOH (or KOH) behaves similar with NaCl (or KCl). When HCl is used as electrolyte, its acidity plays an important role. Phase in-version of microemulsion from type III (or II) to type I is observed through precipitation of Ca2+using Na2CO3, neutralization of HCl by NaOH, and addition of water to the system, which releases the oil from the microemulsion.
基金Supported by the Science and Technology Foundation of Beijing(GYYKW05070015)
文摘To explore the feasibility of extracting aromatic acid products from oxidizing coal, two aromatic acids, trimellitic and [1,1′-biphenyl]-2,2′-dicarboxylic acid, were selected as the solutes, and the extraction equilibrium of the acids were studied with 1-octanol, 50% tributyl phosphate (TBP) in kerosene, and 10% trialkylphosphine oxide (TRPO) in kerosene. The results showed that the degree of extraction of [1,1′-biphenyl]-2,2′-dicarboxylic acid was larger than that of trimellitic acid for all of the solvent, and the extraction capacity with TRPO is more effective than the one with TBP. The extraction behavior of aromatic polyacid is different from that of carboxylic acid, and the reactive extraction function of aromatic acids with TBP and TRPO is not as effective as that of carboxylic acid. 1-octanol could be used to remove [1,1′-biphenyl]-2,2′-dicarboxylic acid from the mixture of trimellitic acid and [1,1′-biphenyl]-2,2′-dicarboxylic acid. Because the weak hydrogen bond association exists between -OH in 1-octanol and -COOH in aromatic acid, the extractive selectivity of [ 1, 1′-biphenyl]-2,2′-dicarboxylic to trimellitic acid depends on the stoichiometric ratio.
文摘A novel method named two-level group contribution (GC-K) method for the estimation of octanol-water partition coefficient (Kow) of chloride hydrocarbon is presented. The equation includes only normal boiling points and molecular weight of compounds. Group contribution parameters of 12 first-level groups and 7 second-level groups for Kow are obtained by correlating experimental data of three types including 57 compounds. By comparing the estimation results of the first-level with that of the two-level groups, it was observed that the latter is better with the addition of the modification of proximity effects. When compared with Marrero's three-level group contribution approach and atom-fragment contribution method (AFC), the accuracy of the average relative error of GC-K by first-level groups is 7.20% and is preferred to other methods.
基金Supported by the National High Technical Research Program of China(2012AA03A606)the Project of Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)+1 种基金the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(12KJA530001)the Innovative Research Team Program by the Ministry of Education of China(IRT13070)
文摘As a new kind of2D nanomaterials, graphene oxide (GO) with 2-4 layers was fabricated rio a modified Hummers method and used for the preparation ofpervaporation (PV) membranes. Such GO membranes were prepared via a facile vacuum-assisted method on anodic aluminium oxide disks and applied for the dehydration of butanol. To obtain GO membranes with high performance, effects of pre-treatments, including high-speed centrifugal treat- ment of GO dispersion and thermal treatment of GO membranes, were investigated. In addition, effects of operation conditions on the performance of GO membranes in the PV process and the stability of GO membranes were also studied. It is of benefit to improve the selectivity of GO membrane by pre-treatment that centrifuges the GO dispersion with 10000 r· min^- 1 for 40 min, which could purify the GO dispersion by removing the large size GO sheets. As prepared GO membrane showed high separation performance for the butanol/water system. The separation factor was 230, and the permeability was as high as 3.1 kg·m^- 2·h^-1 when the PV temperature was 50 ℃ and the water content in feed was 10% (by mass). Meanwhile, the membrane still showed good stability for the dehydration of butanol after running for 1800 min in the PV process. GO membranes are suitable candidates for butanol dehydration via PV process.
基金Supported by the National Basic Research Program of China (2007CB714300)
文摘The esterification reactions of lactic acid with isobutanol and n-butanol have been studied in the presence of acid ion-exchange resin Weblyst D009. The influences of catalyst loading, stirrer speed, catalyst particle size, initial reactant molar ratio and temperature on the reaction rate have been examined. Experimental kinetic data were correlated by using the pseudo-homogeneous, Langnluir-Hinshelwood and Eley-Rideal models. Nonideality of the liquid phase was taken into account by using activities instead of molar fractions. The activity coefficients were calculated according to the group contribution method UNIFAC. Provided that the nonideality of the liquid is taken into account, the esterification kinetics of lactic acid with isobutanol and n-butanol catalyzed by the acid ion-exchange resin can be described using all threemodels with reasonable errors.
基金Supported by the National Natural Science Foundation of China(21306036)the Basic Research Program of Hebei Province(16964502D)
文摘The separation of ternary mixture of butanol, butyl acetate, and methyl isobutyl ketone(MIBK) was initially analyzed by the residual curve. In this process, MIBK was chosen as the azeotropic agent during the first step of separation. The optimum mass ratio of extra MIBK was 1.6 in the modified feed stream according to the residual curve. Thus on this condition the top product was butanol-MIBK azeotrope while the bottom product was butyl acetate in the preliminary separation of the mixture. Then the butanol and MIBK azeotrope was separated by the double effect pressureswing distillation with the low pressure column performing at 30 kPa and the atmospheric pressure column at 101 kPa. The optimal operating conditions were then obtained by using Aspen Plus to simulate and optimize the process. The results showed that the mass purities of butanol, butyl acetate, and MIBK were all more than 99% and reached the design requirements. Additionally, compared with the traditional distillation with outside heating, the double effect pressure swing distillation saved the reboiler duty by 48.6% and the condenser duty by 44.6%.
基金Supported by the Natural Science Foundation of Zhejiang Province (No. 299018).
文摘The forming mechanism of microemulsion of sodium dodecyl sulfonate, alcohols,water and isooctane was studied, with particular emphasis on the effect of molecular weight andconcentration of alcohols. Phase diagram of the four components, alcohol, sodium dodecyl sulfonate,water and isooctane, was used as a means of study, through which the microemulsion regions weredetermined. Phase diagram of sodium dodecyl sulfonate/n-pentanol/isooctane/water system at κ_m = 2(κ_m = W_(n-pentanol)/W_(SDS)) is presented. The variation of conductivities of differentmicroemulsion samples with water was measured. From the conductivities we investigated a change instructure from water droplets in oil (W/O) at low water content to liquid crystal at intermediatewater content and a stricture of oil droplets in water (O/W) at high water content.
基金financial support of the National Natural Science Foundation of China (No.51374051)the Fundamental Research Fund for the Central Universities (No.N130401008)
文摘In order to investigate the effect of butanol on quartz flotation when N-dodecyl ethylenediamine(ND)was used as collector, single mineral flotation and artificial mixed mineral(hematite and quartz were mixed at a mass ratio of 3:2) separation were conducted in the laboratory. Experimental results indicated that addition of butanol could improve the collecting performance of ND on quartz and enhance the floatability of quartz. Best flotation recovery of quartz was obtained when butanol was mixed with ND at a mass ratio of 1:1. Moreover, the molecular structure of alcohols had a significant effect on mineral recovery. Best separation efficiency could be obtained when tert-butanol was added as it had the largest cross-sectional area. Zeta potential measurements indicated that alcohols could strengthen electrostatic adsorption between quartz and collector. Molecular dynamic simulations revealed that co-adsorption of alcohols along with ND had taken place on the quartz surface, and ND/tert-butyl combinations were more easily absorbed on the quartz surface.
基金Supported by the National Council of Science and Technology(CONACyT)(SEP-2004-C01-47817)
文摘Densities(ρ) and dynamic viscosities(η) for three binary mixtures of n-decane with 1-pentanol,1-hexanol and1-heptanol are presented at temperatures from 293.15 to 363.15 K and atmospheric pressure over the entire composition range.The density and viscosity are measured using a vibrating tube densimeter and a cylindrical Couette type rotating viscometer,respectively.Excess molar volumes(V^E),viscosity deviations(△η) and excess Gibbs energy of activation of viscous flow(△G^(*E)) are calculated from the experimental measurements.Intermolecular and structural interactions are indicated by the sign and magnitude of these properties.Partial molar volumes and infinity dilution molar partial volumes are also calculated for each binary system.These results are correlated using Redlich-Kister type equations.
基金Supported by the Ministry of Education of Henan Province in China (2011A610004)
文摘The distributions of nicotinic acid (NA) between water and trialkylamine (N235) dissolved in n-octanol was studied. The complexes of N235 and NA were investigated by Fourier transformation infrared spectrometry to deduce the reaction mechanism. It was found that N235/n-octanol was an efficient extractant for extracting nicotinic acid. The favorable operation conditions were equilibrium aqueous pH 4.2 to 5.5 and initial N235 concentration<0.42 mol·L-1 . The reaction processes included the reaction between neutral N235 and neutral NA and the reaction between protonated N235 and anionic NA. Based on the mass action law and some assumptions, an expression for distribution coefficient D was proposed. The apparent extraction equilibrium constants were calculated by fitting the experimental data and the results were satisfactory.
基金Supported by the National Natural Science Foundation of China(21376053)
文摘Based on a previous investigation,a simulation model was used for optimization of coproduction of ethyl acetate and n-butyl acetate by reactive distillation.An experimental setup was established to verify the simulated results.The effects of various operating variables,such as ethanol feed location,acetic acid feed location,feed stage of reaction mixture of acetic acid and n-butanol,reflux ratio of ethyl acetate reactive distillation column,and distillate to feed ratio of n-butyl acetate column,on the ethanol/n-butanol conversions,ethyl acetate/n-butyl acetate purity,and energy consumption were investigated.The optimal results in the simulation study are as follows:ethanol feed location,15th stage;acetic acid feed location,eighth stage;feed location of reaction mixture of acetic acid and n-butanol,eighth stage;reflux ratio of ethyl acetate reactive distillation column,2.0;and distillate to feed ratio of n-butyl acetate,0.6.
文摘It is already well known that availability of petroleum oil, as a world energy source, is running low. Much work has been done by experts to produce renewable energy, especially using vegetable oil as a raw material. Accordingly, this paper presents preparation and activity test of Cu catalyst using coconut shell activated carbon (AC) as a support, for conversion of n-pentanol and n-butanol to their alkenes as the first step of conversion of ethanol to biogasoline. This conversion is interesting due to any agriculture product containing sugar or starch can be converted to ethanol. Activated carbon was used as a catalyst support because this material is inert; hence, it would not yield unexpected side product, and pollution of environment with the used catalyst can be prevented because the used catalytic metal can easily be recovered. Results of the work showed that coconut shell carbon contained some metals, which disturbed in preparation catalyst by cation exchange process. Washing the carbon with ammonium acetate or HCI solution could reduce the metals content more compared to using water, with optimum concentration for ammonium acetate solution was 1.25 M. Application of Cu/AC in converting n-pentanol and n-butanol, based on qualitative analysis to the products using GLC, GC-MS, and FTIR, when n-pentanol and nitrogen gas were flowed into a reactor filled with Cu/AC catalyst, it could be converted to n-pentene with 200 ℃ as the optimal temperature. While when n-butanol and nitrogen gas were flowed into a reactor filled with more Cu/AC catalyst, the product was supposed to contain its aldehyde and butyl vinyl ether.
文摘Neuromuscular junction is the main target for snakebites, which venoms act depending on the snake genus for paralyzing the prey (neurotoxicity) or for facilitating the digestion processes of the victim (myotoxicity), and also as a defense mechanism against predators. In the present study, a mouse neuromuscular apparatus was used for testing the hexane fraction of Casearia gossypiosperma plant, that showed the better antiophidian ability than dichloromethane, ethyl acetate and methanol fractions, against the irreversible paralysis induced by two, Bothrops jararacussu (Bjssu, 40 μg/mL) and Crotalus durissus terrificus (Cdt, 10 μg/mL) snake venoms. All fractions were obtained by liquid-liquid partition from the C. gossypiosperma hydroalcoholic lyophilized extract. The preliminary chromatographic profile of this plant showed phenols and flavonols as active constituents, whereas hexane fraction expressed mainly 13-sitosterol and quercetin. In spite of hexane fraction protection (≌95% and 48% against Bjssu and Cdt, respectively), isolately, only quercetin protected against the blockade-induced by Bjssu venom (65.5%). This study showed that hexane fraction acts against these snake venoms by a synergistic phytocomplex mechanism.