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Sample records for azeotrope

  1. Separation processes, I: Azeotropic rectification

    Directory of Open Access Journals (Sweden)

    Milojević Svetomir

    2005-01-01

    Full Text Available In a series of two articles, the problems of azeotrope separation (part I and the design of separation units (part II were analyzed. The basic definition and equations of vapour-liquid equilibria for ideal and non-ideal systems, the importance of the activity coefficient calculation necessary for the analysis of non-ideal equilibrium systems, as well as theoretical aspects of azeotrope rectification and the determination of the optimal third component (modifier or azeotrope agent are presented in the first part.

  2. Simultaneous Design of Ionic Liquids and Azeotropic Separation Processes

    DEFF Research Database (Denmark)

    Roughton, Brock C.; White, John; Camarda, Kyle V.;

    2011-01-01

    A methodology for the design of azeotrope separation processes using ionic liquids as entrainers is outlined. A Hildebrand solubility parameter group contribution model has been developed to screen for or design an ionic liquid entrainer that is soluble with the azeotropic components. Using...... the best candidate, vapor-liquid equilibria data is predicted using a new ionic liquid UNIFAC model that has been developed. The UNIFAC model is used to confirm the breaking of the azeotrope. The methanol-acetone azeotrope at 1 atm is used as an example. The azeotrope was predicted to break with 10 mol...... % [BMPy][BF4] added. The driving force concept is used to design an extractive distillation process that minimizes energy inputs. The methodology given can be expanded to the use of ionic liquids as entrainers in any azeotropic system of interest....

  3. Static multiplicities in heterogeneous azeotropic distillation sequences

    DEFF Research Database (Denmark)

    Esbjerg, Klavs; Andersen, Torben Ravn; Jørgensen, Sten Bay;

    1998-01-01

    In this paper the results of a bifurcation analysis on heterogeneous azeotropic distillation sequences are given. Two sequences suitable for ethanol dehydration are compared: The 'direct' and the 'indirect' sequence. It is shown, that the two sequences, despite their similarities, exhibit very...... performances are compared for minimal impurities in both products, where the direct sequence exhibits output multiplicity, while the indirect sequence exhibits state multiplicity. The latter multiplicity may be avoided by accepting a slightly increased impurity in the ethanol product. Copyright (C) 1998 IFAC....

  4. Responses of azeotropes and relative volatilities to pressure variations

    DEFF Research Database (Denmark)

    Abildskov, Jens; O’Connell, John P.

    2015-01-01

    of two columns. Because operating costs are highly sensitive to the pressure dependence of azeotropic compositions, reliable and accurate phase equilibrium thermodynamic property information is needed to computationally explore pressure variation for such processes. An analysis of property modeling has...

  5. Development of a robust algorithm to compute reactive azeotropes

    Directory of Open Access Journals (Sweden)

    M. H. M. Reis

    2006-09-01

    Full Text Available In this paper, a novel approach for establishing the route for process intensification through the application of two developed softwares to characterize reactive mixtures is presented. A robust algorithm was developed to build up reactive phase diagrams and to predict the existence and the location of reactive azeotropes. The proposed algorithm does not depend on initial estimates and is able to compute all reactive azeotropes present in the mixture. It also allows verifying if there are no azeotropes, which are the major troubles in this kind of programming. An additional software was developed in order to calculate reactive residue curve maps. Results obtained with the developed program were compared with the published in the literature for several mixtures, showing the efficiency and robustness of the developed softwares.

  6. Ionic-Liquid Based Separation of Azeotropic Mixtures

    DEFF Research Database (Denmark)

    Kulajanpeng, Kusuma; Suriyapraphadilok, Uthaiporn; Gani, Rafiqul

    2014-01-01

    such as stability, toxicity, and environmental impacts of the ILs. A Hildebrand solubility parameter group contribution model for ILs is highlighted to screen the miscibility of the ILs with the target solute component which was considered as a key target property to further screen the candidates from the previous...... on minimum concentration of the ILs required to break the given azeotrope, the best ILs as entrainers for water + ethanol and water + isopropanol azeotropic mixtures were [C1MIM][DMP] and [C2MIM][N(CN)2], respectively....

  7. Azeotropic binary solvent mixtures for preparation of organic single crystals

    NARCIS (Netherlands)

    Li, X.; Kjellander, B.K.C.; Anthony, J.E.; Bastiaansen, C.W.M.; Broer, D.J.; Gelinck, G.H.

    2009-01-01

    Here, a new approach is introduced to prepare large single crystals of π-conjugated organic molecules from solution. Utilizing the concept of azeotropism, single crystals of tri-isopropylsilylethynyl pentacene (TIPS-PEN) with dimensions up to millimeters are facilely self-assembled from homogeneous

  8. Adsorption isotherm of non-azeotropic solution onto porous adsorbents

    Science.gov (United States)

    Bono, A.; Ramlan, N. A.; Anisuzzaman, S. M.; Chu, C. M.; Farm, Y. Y.

    2016-06-01

    Adsorption isotherm is essential component in the understanding of the adsorption process. Several methods of the measurements, analysis and interpretation of adsorption from solution have been reported in the literature. Most of the measurements of adsorption isotherm from solution were involved the measurement of excess isotherm conducted at low region of sorbates concentration. Direct interpretation of excess adsorption isotherm as adsorption isotherm is always been practice. Therefore, in this work a study on the measurement of the adsorption isotherm from solution of non-azeotropic organic solvent mixture onto porous adsorbents for whole range of liquid concentration was conducted. The study included the measurement of excess adsorption isotherm using conventional technique. Theoretical analysis and interpretation of adsorption isotherm from the excess isotherm were conducted using Pseudo Ideal Adsorption, Gibbs Dividing Plane Model and Langmuir-Fruendlich binary isotherm model. For organic solvents, acetone and propanol were chosen as the adsorbates due to the non-azeotropic properties in the mixture. Activated carbon and silicalite were chosen as adsorbents due to the different in their porosity such as macro porous and micro porous structure. The result of the study has revealed that the adsorption isotherm of non-azeotropic mixture onto activated carbon and silicalite can be interpreted as monolayer type of adsorption.

  9. Simultaneous design of ionic liquid entrainers and energy efficient azeotropic separation processes

    DEFF Research Database (Denmark)

    Roughton, Brock C.; Christian, Brianna; White, John;

    2012-01-01

    A methodology and tool set for the simultaneous design of ionic liquid entrainers and azeotropic separation processes is presented. By adjusting the cation, anion, and alkyl chain length on the cation, the properties of the ionic liquid can be adjusted to design an entrainer for a given azeotropic...... mixture. Several group contribution property models available in literature have been used along with a newly developed group contribution solubility parameter model and UNIFAC model for ionic liquids (UNIFAC-IL). For a given azeotropic mixture, an ionic liquid is designed using a computer-aided molecular...... material and energy requirements when compared to an ionic liquid known to experimentally break a given azeotrope but not designed using CAMD methods. The acetone–methanol and ethanol–water azeotropes are provided as examples....

  10. Simultaneous Design of Ionic Liquids and Azeotropic Separation for Systems Containing Water

    DEFF Research Database (Denmark)

    Roughton, Brock; Camarda, Kyle V.; Gani, Rafiqul

    to check for consistency. The ionic liquid UNIFAC model was developed for a selected set of ionic liquid cations and anions. Group volume and area parameters were calculated using a three step procedure. First, the rules of Bondi were used for any applicable molecular groups within the cation or anion...... decomposition temperature. For any new synthesis-design problem involving aqueous azeotropes, all it now requires is to find the azeotropic composition of water and based on it, to identify an appropriate ionic liquid. Then the driving force is calculated for the azeotrope ionic liquid and based on it...

  11. Study on Azeotropic Point of Azeotrope with Two Components%对二元溶液体系共沸溶液共沸点的再探究

    Institute of Scientific and Technical Information of China (English)

    曲金华; 杨旭

    2014-01-01

    共沸溶液很早就被人们所发现并取得了大量的实验数据,然而,这种现象的理论研究却很少。本文从理论上推导出二元体系共沸液的共沸点与外压、组成和组分沸点的定量关系式,并据此计算了二元体系共沸溶液常压下的共沸点,结果与文献的实验数据有相当好的一致性。本文还对二元体系共沸溶液的存在范围,共沸点相对单组分沸点高低的定性判定作了分析,从而为共沸溶液的研究和应用提供了理论依据。%Azeotropic solution soon discovered by the people and made the experimental data, a lot of however, theoretical study of this phenomenon is rarely. Quantitative relationship between the theoretically deduced two azeotropic distillation liquid boiling point and external pressure, composition and component boiling point, two component azeotropic solution under atmospheric pressure boiling point was calculated accordingly, the result of experimental data and literature are quite agreement. This paper also points the existence range azeotropic solution of the two group, boiling point to determine relative single component boiling point of qualitative analysis is made, which provides a theoretical basis for the research and application of azeotropic solution.

  12. Anthracene + Pyrene Solid Mixtures: Eutectic and Azeotropic Character.

    Science.gov (United States)

    Rice, James W; Fu, Jinxia; Suuberg, Eric M

    2010-09-01

    To better characterize the thermodynamic behavior of a binary polycyclic aromatic hydrocarbon mixture, thermochemical and vapor pressure experiments were used to examine the phase behavior of the anthracene (1) + pyrene (2) system. A solid-liquid phase diagram was mapped for the mixture. A eutectic point occurs at 404 K at x(1) = 0.22. A model based on eutectic formation can be used to predict the enthalpy of fusion associated with the mixture. For mixtures that contain x(1) < 0.90, the enthalpy of fusion is near that of pure pyrene. This and X-ray diffraction results indicate that mixtures of anthracene and pyrene have pyrene-like crystal structures and energetics until the composition nears that of pure anthracene. Solid-vapor equilibrium studies show that mixtures of anthracene and pyrene form solid azeotropes at x(1) of 0.03 and 0.14. Additionally, mixtures at x(1) = 0.99 sublime at the vapor pressure of pure anthracene, suggesting that anthracene behavior is not significantly influenced by x(2) = 0.01 in the crystal structure.

  13. Azeotropic distillation assisted fabrication of silver nanocages and their catalytic property for reduction of 4-nitrophenol.

    Science.gov (United States)

    Min, Jianzhong; Wang, Fei; Cai, Yunliang; Liang, Shuai; Zhang, Zhenwei; Jiang, Xingmao

    2015-01-14

    Monodisperse silver nanocages (AgNCs) with specific interiors were successfully synthesized by an azeotropic distillation (AD) assisted method and exhibited excellent catalytic activities for reduction of 4-nitrophenol (4-NP) into 4-aminophenol (4-AP) due to the unique hollow morphology and small thickness of the silver shell.

  14. Preparation of highly dispersed antimony-doped tin oxide nanopowders by azeotropic drying with isoamyl acetate

    Institute of Scientific and Technical Information of China (English)

    YANG Fen; ZHANG Xue-jun; WU Xu; TIAN Fang; GAN Fu-xing

    2007-01-01

    Antimony-doped tin hydroxide colloid precipitates were prepared by hydrolysis of SnCl4-5H2O and SbCl3 ethanol solutions. Isoamyl acetate was selected as azeotropic drying solvent and was compared with the most commonly used n-butanol solvent on treating precipitate for low hard agglomeration precursor powders. The FT-IR, BET, XRD, and TEM results of the precursor powders and calcinated antimony-doped tin oxide powders were recorded. The results demonstrate that isoamyl acetate is an excellent azeotropic drying solvent that can effectively prevent the agglomeration of particles and greatly improve the fluffiness of the obtained dried powders. After these precursor powders are calcined, antimony-doped tin oxide nanopowders with tetragonal rutile structure and high dispersivity can be obtained.

  15. Thermodynamic Study on the Azeotropic Mixture Composed of Ethanol and Toluene

    Institute of Scientific and Technical Information of China (English)

    南照东; 谭志诚; 邢军

    2005-01-01

    The molar heat capacity of the azeotropic mixture composed of ethanol and toluene was measured by a high precision adiabatic calorimeter from 80 to 320 K. The glass transition and phase transitions of the azeotropic mixture were determined based on the heat capacity measurements. A glass transition at 103.350 K was found. A solid-solid phase transition at 127.282 K, two solid-liquid phase transitions at 153.612 and 160.584 K were observed, which correspond to the transition of metastable crystal to stable crystal of ethanol and the melting of ethanol and toluene, respectively. The thermodynamic functions and the excess ones of the mixture relative to the standard temperature 298.15 K were derived based on the relationships of the thermodynamic functions and the function of the measured heat capacity with respect to temperature.

  16. New extractive configuration separating azeotropic mixture in semi-batch way

    OpenAIRE

    Stéger, Csaba; Rev, Endre; Horvath, Laszlo; Fonyo, Zsolt; Meyer, Michel; Lelkes, Zoltan

    2006-01-01

    A new variant of batch extractive distillation, the so-called inverse-fed batch extractive distillation is presented. The total amount of the entrainer is pre-loaded to the boiler, and the mixture charge to be separated is continuously fed to the column in this novel configuration. The feasibility study of conventional extractive distillation was extended and a thorough study was performed to separate a maximum boiling azeotrope with intermediate boiling entrainer. The new configuration was f...

  17. Correlation for fitting multicomponent vapor-liquid equilibria data and prediction of azeotropic behavior

    Directory of Open Access Journals (Sweden)

    Khalid Farhod Chasib Al-Jiboury

    2007-01-01

    Full Text Available Correlation equations for expressing the boiling temperature as direct function of liquid composition have been tested successfully and applied for predicting azeotropic behavior of multicomponent mixtures and the kind of azeotrope (minimum, maximum and saddle type using modified correlation of Gibbs-Konovalov theorem. Also, the binary and ternary azeotropic point have been detected experimentally using graphical determination on the basis of experimental binary and ternary vapor-liquid equilibrium data.In this study, isobaric vapor-liquid equilibrium for two ternary systems: “1-Propanol – Hexane – Benzene” and its binaries “1-Propanol – Hexane, Hexane – Benzene and 1-Propanol – Benzene” and the other ternary system is “Toluene – Cyclohexane – iso-Octane (2,2,4-Trimethyl-Pentane” and its binaries “Toluene – Cyclohexane, Cyclohexane – iso-Octane and Toluene – iso-Octane” have been measured at 101.325 KPa. The measurements were made in recirculating equilibrium still with circulation of both the vapor and liquid phases. The ternary system “1-Propanol – Hexane – Benzene” which contains polar compound (1-Propanol and the two binary systems “1-Propanol – Hexane and 1-Propanol – Benzene” form a minimum azeotrope, the other ternary system and the other binary systems do not form azeotrope.All the data passed successfully the test for thermodynamic consistency using McDermott-Ellis test method (McDermott and Ellis, 1965.The maximum likelihood principle is developed for the determination of correlations parameters from binary and ternary vapor-liquid experimental data which provides a mathematical and computational guarantee of global optimality in parameters estimation for the case where all the measured variables are subject to errors and the non ideality of both vapor and liquid phases for the experimental data for the ternary and binary systems have been accounted.The agreement between prediction and experimental data is

  18. Non azeotrope mixing refrigerating fluids condensation outside of an horizontal tubes stack; Condensation de melanges non azeotropes de fluides frigorigenes a l'exterieur d'un faisceau de tubes horizontaux

    Energy Technology Data Exchange (ETDEWEB)

    Signe, J.Ch.

    1999-04-16

    The development of non-azeotrope mixing, as regular refrigerating fluids substitute, calls in question the experience for the design of refrigerating and cooling machinery. Studies to better understand these fluids behaviour are necessary. The aim of this thesis is the knowledge enlargement on the pure fluids and non azeotrope mixing condensation, outside of a tubes stack, and to simulate the heat transfers. The tubes stack is a condenser, type TEMA X often used in refrigerating machinery. The binary mixing HFC 134a-HFC23, allows a large sliding scale. (A.L.B.)

  19. Influence of Magnetic Field on the Rectification Process of Binary Heterogeneous Azeotrope

    Institute of Scientific and Technical Information of China (English)

    JIA Shaoyi; WU Songhai; LI Zhen; JIA Liang

    2005-01-01

    To improve separate effect of binary heterogeneous azeotrope in the magnetic field with different magnetic induction intensity, the influence of magnetic field on the rectification process of binary heterogeneous azeotrope was investigated with 1-butanol-water system. The results show that the composition of liquid-liquid phase equilibrium of 1-butanol-water system has definitely changed, the composition of 1-butanol in light phase (1-butanol layer) increases by 1.17%-1.63% and the composition of water in heavy phase (water layer) increases by 1.21%-1.58% under the influence of magnetic field. By separation of magnetization, the composition of 1-butanol increases by 0.8%-1.2% and the recovery ratio of 1-butanol increases by 1.6%-2.5%. Magnetic field has positive effect, however, the magnetized effect is not in proportion to magnetic induction intensity and has an optimum condition, in the range of 0.25 T-0.3 T.

  20. Activation of aqueous hydrogen peroxide for non-catalyzed dihydroperoxidation of ketones by azeotropic removal of water.

    Science.gov (United States)

    Starkl Renar, K; Pečar, S; Iskra, J

    2015-09-28

    Cyclic and acyclic ketones were selectively converted to gem-dihydroperoxides in 72-99% yield with 30% aq. hydrogen peroxide by azeotropic distillation of water from the reaction mixture without any catalyst. The reactions were more selective than with 100% H2O2 and due to neutral conditions also less stable products could be obtained.

  1. Synthesis of ZnO doped ceria nanoparticles via azeotropic distillation processing

    Institute of Scientific and Technical Information of China (English)

    SONG Xiao-lan; QU Peng; YANG Hua-ming; QIU Guan-zhou

    2006-01-01

    The synthesis of nano-sized ZnO-doped CeO2 of 20 nm in crystal size by a coprecipitation technique was investigated by different scanning calorimetries/thermalgravimetrics(DSC/TG),X-ray diffraction (XRD),transmission electron microscopy (TEM) and ultraviolet (UV) absorbance. Azeotropic distillation processing was performed to effectively eliminate the residual water inside the as-prepared precipitate. Doping of ZnO results in the formation of solid solution. The crystal size of the nanoparticles increases with the increase of the doped ZnO amount,the calcination temperature and time. Doped CeO2 nanoparticles show excellent visible-light property and ultraviolet-absorption activity. Doping of ZnO doesn't not weaken the UV-shielding property of ceria.

  2. Thermodynamic Investigation of the Azeotropic Mixture Composed of Water and Benzene

    Institute of Scientific and Technical Information of China (English)

    NAN,Zhao-Dong(南照东); TAN,Zhi-Cheng(谭志诚)

    2004-01-01

    The molar heat capacity of the azeotropic mixture composed of water and benzene was measured by an adiabatic calorimeter in the temperature range from 80 to 320 K. The phase transitions took place in the temperature range from 265.409 to 275.165 K and 275.165 to 279.399 K. The phase transition temperatures were determined to be 272.945 and 278.339 K, which were corresponding to the solid-liquid phase transitions of water and benzene, respectively. The thermodynamic functions and the excess thermodynamic functions of the mixture relative to standard temperature 298.15 K were derived from the relationships of the thermodynamic functions and the function of the measured heat capacity with respect to temperature.

  3. Ethanol-Water Near-Azeotropic Mixture Dehydration by Compound Starch-Based Adsorbent

    Institute of Scientific and Technical Information of China (English)

    孙津生; 师明; 王文平

    2015-01-01

    Ethanol-water near-azeotropic mixture dehydration was investigated by formulated compound starch-based adsorbent(CSA), which consists of corn, sweet potato and foaming agent. The net retention time and separa-tion factor of water over ethanol were measured by inverse gas chromatography(IGC). Results indicated that water has a longer net retention time than ethanol and that low temperature is beneficial to this dehydration process. Or-thogonal test was conducted under different vapor feed flow rates, bed temperatures and bed heights, to obtain op-timal fixed-bed dehydration condition. Dynamic saturated adsorbance was also studied. It was found that CSA has the same water adsorption capacity(0.15 g/g)as some commercial molecular sieves. Besides, this biosorptive dehy-dration process was found to be the most energy-efficient compared with other ethanol purification processes.

  4. Optimization study of pressure-swing distillation for the separation process of a maximum-boiling azeotropic system of water-ethylenediamine

    Energy Technology Data Exchange (ETDEWEB)

    Fulgueras, Alyssa Marie; Poudel, Jeeban; Kim, Dong Sun; Cho, Jungho [Kongju National University, Cheonan (Korea, Republic of)

    2016-01-15

    The separation of ethylenediamine (EDA) from aqueous solution is a challenging problem because its mixture forms an azeotrope. Pressure-swing distillation (PSD) as a method of separating azeotropic mixture were investigated. For a maximum-boiling azeotropic system, pressure change does not greatly affect the azeotropic composition of the system. However, the feasibility of using PSD was still analyzed through process simulation. Experimental vapor liquid equilibrium data of water-EDA system was studied to predict the suitability of thermodynamic model to be applied. This study performed an optimization of design parameters for each distillation column. Different combinations of operating pressures for the low- and high-pressure columns were used for each PSD simulation case. After the most efficient operating pressures were identified, two column configurations, low-high (LP+HP) and high-low (HP+ LP) pressure column configuration, were further compared. Heat integration was applied to PSD system to reduce low and high temperature utility consumption.

  5. Preparation of ultrafine a-Al2O3 using precipitation-azeotropic distillation method

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Ammonium aluminum carbonate hydroxide (AACH) was prepared by a precipitation-azeotropic distillation method,which uses aluminum sulfate as the Al source and ammonium carbonate as the precipitant.Then,AACH was calcined into ultrafine α-Al2O3 powder.The factors that influence the dispersion property of ultrafine α-Al2O3 powder are discussed in this paper,such as the methods of adding materials,surfactant,and drying methods.The changes of the structure and property of ultrafine alumina in the thermal treatment process are also studied.The morphological structure and properties of AACH are characterized by DTA/TGA,SEM,XRD,and ICP measurements.The results show that ultrafine α-Al2O3 powder with a uniform particle size and well-distributed property can be synthesized only after aluminum sulfate atomizes into ammonium carbonate,proper amount of PEG1000 is added as the dispersant,and the product is treated by azeotropic distillation.The phase transformation of alumina during the calcination process can be described as amorphous Al2O3→γ-Al2O3→θ-Al2O3→α-Al2O3.The crystal grain size and density of ultrafine alumina powder increase with the increase of the calcination temperature.After AACH has been calcined at 1200℃ for 2 h,the ultrafine α-Al2O3 with uniform particle size,spherical shape,and more than 99.97% purity is obtained and its powder is well dispersed.

  6. Preparation and Characterization of La0.8Sr0.2MnO3-δ Cathode for SOFCs Fabricated Using Azeotropic Distillation Method

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Strontium doped lanthanum manganite (LSM) powders were synthesized by three different routes: azeotropic distillation, sol-gel and solid state reaction respectively. The LSM samples, made by azeotropic distillation and sol-gel methods were prepared by firing at 1000 ℃ for 6 h, and the LSM sample, made by solid state reaction method was produced by sintering at 1400 ℃ for 18 h. The samples were characterized by XRD, TEC, SEM, EIS and polarization performance analysis. The results show that all the samples made by different methods have pure orthorhombic LSM phase, however exhibit different micro structure and electrochemical characterization, which relates to the different synthesis methods. The solid state reaction method produces the samples with larger particle size compared with azeotropic distillation and sol-gel methods. The powders made by azeotropic distillation method have less agglomerated particles compared with that made by sol-gel method because the precursor in the former is dispersed in n-butanol before sintering. The polarization current density of powder made by azeotropic distillation method was twice of that made by sol-gel method and four times of that made by solid state reaction method. The values of polarization resistance (Rp) are 0.35 Ω·cm2 for the cathode synthesized by azeotropic distillation route, which is much lower than sol-gel (1.5 Ω·cm2) and solid state reaction (2.3 Ω·cm2) at 800 ℃.

  7. Convective Boiling of Near-Azeotropic Refrigerant R410A in the Horizontal Micro-fin Tube

    Institute of Scientific and Technical Information of China (English)

    DUAN Xue-tao; MA Hu-gen; WU Zhi-min; WANG Fang

    2007-01-01

    Using near-azeotropic refrigerant R410A as the working fluid, the experimental studies on the horizontal micro-fin tubes were conducted. Several factors affecting heat transfer coefficients were analyzed, and the characteristics of flow boiling of the refrigerant in the horizontal micro-fin tubes were discussed. The local heat transfer coefficients increase with mass flux, heat flux and quality. And the heat transfer enhancement factor of those testing tubes is about 1.6 to 2.2.

  8. Adsorption of binary gas mixtures in heterogeneous carbon predicted by density functional theory: on the formation of adsorption azeotropes.

    Science.gov (United States)

    Ritter, James A; Pan, Huanhua; Balbuena, Perla B

    2010-09-07

    Classical density functional theory (DFT) was used to predict the adsorption of nine different binary gas mixtures in a heterogeneous BPL activated carbon with a known pore size distribution (PSD) and in single, homogeneous, slit-shaped carbon pores of different sizes. By comparing the heterogeneous results with those obtained from the ideal adsorbed solution theory and with those obtained in the homogeneous carbon, it was determined that adsorption nonideality and adsorption azeotropes are caused by the coupled effects of differences in the molecular size of the components in a gas mixture and only slight differences in the pore sizes of a heterogeneous adsorbent. For many binary gas mixtures, selectivity was found to be a strong function of pore size. As the width of a homogeneous pore increases slightly, the selectivity for two different sized adsorbates may change from being greater than unity to less than unity. This change in selectivity can be accompanied by the formation of an adsorption azeotrope when this same binary mixture is adsorbed in a heterogeneous adsorbent with a PSD, like in BPL activated carbon. These results also showed that the selectivity exhibited by a heterogeneous adsorbent can be dominated by a small number of pores that are very selective toward one of the components in the gas mixture, leading to adsorption azeotrope formation in extreme cases.

  9. Dehydration of an ethanol/water azeotrope through alginate-DNA membranes cross-linked with metal ions by pervaporation.

    Science.gov (United States)

    Uragami, Tadashi; Banno, Masashi; Miyata, Takashi

    2015-12-10

    To obtain high dehydration membranes for an ethanol/water azeotrope, dried blend membranes prepared from mixtures of sodium alginate (Alg-Na) and sodium deoxyribonucleate (DNA-Na) were cross-linked by immersing in a methanol solution of CaCl2 or MaCl2. In the dehydration of an ethanol/water azeotropic mixture by pervaporation, the effects of immersion time in methanol solution of CaCl2 or MaCl2 on the permeation rate and water/ethanol selectivity through Alg-DNA/Ca(2+) and Alg-DNA/Mg(2+) cross-linked membranes were investigated. Alg-DNA/Mg(2+) cross-linked membrane immersed for 12h in methanol solution of MaCl2 exhibited the highest water/ethanol selectivity. This results from depressed swelling of the membranes by formation of a cross-linked structure. However, excess immersion in solution containing cross-linker led to an increase in the hydrophobicity of cross-linked membrane. Therefore, the water/ethanol selectivity of Alg-DNA/Mg(2+) cross-linked membranes with an excess immersion in cross-linking solution was lowered. The relationship between the structure of Alg-DNA/Ca(2+) and Alg-DNA/Mg(2+) cross-linked membranes and their permeation and separation characteristics during pervaporation of an ethanol/water azeotropic mixture is discussed in detail.

  10. Thermodynamic Properties of the Azeotropic Mixture of Acetone, Cyclohexane and Methanol

    Institute of Scientific and Technical Information of China (English)

    WANG Xiu-Rong; NAN Zhao-Dong; TAN Zhi-Cheng

    2006-01-01

    Molar heat capacities of the pure samples of acetone, methanol and the azeotropic mixture composed of acetone,cyclohexane and methanol were measured by an adiabatic calorimeter from 78 to 320 K. The solid-solid and solid-liquid phase transitions of the pure samples and the mixture were determined based on the curve of the heat capacity with respect to temperature. The phase transitions took place at (126.16±0.68) and (178.96±1.47) K for the sample of acetone, (157.79±0.95) and (175.93±0.95) K for methanol, which were corresponding to the solid-solid and the solid-liquid phase transitions of the acetone and the methanol, respectively. And the phase transitions occurred in the temperature ranges of 120 to 190 K and 278 to 280 K corresponding to the solid-solid and the solid-liquid phase transitions of mixture of acetone, cyclohexane and methanol, respectively. The thermodynamic functions and the excess thermodynamic functions of the mixture relative to standard temperature of 298.15 K were derived based on the relationships of the thermodynamic functions and the function of the measured heat capacity with respect to temperature.

  11. Decay rate of critical fluctuations in ethane + carbon dioxide mixtures near the critical line including the critical azeotrope

    Science.gov (United States)

    Chang, R. F.; Doiron, T.; Pegg, I. L.

    1986-03-01

    Using the technique of photon correlation spectroscopy we have measured the decay rate of critical fluctuations in mixtures of ethane and carbon dioxide of various compositions including a near-azeotropic mixture. Our experimental data indicate that there is only one dominant mode of fluctuations and the decay rate is well described by the predictions of the mode-coupling theory with the exponent v=0.63 for all compositions. The decay rate, its background contributions, the shear viscosity, and the correlation length for the mixtures appear to interpolate simply between those of ethane and carbon dioxide.

  12. Decay rate of critical fluctuations in ethane+carbon dioxide mixtures near the critical line including the critical azeotrope

    Energy Technology Data Exchange (ETDEWEB)

    Chang, R.F.; Doiron, T.; Pegg, I.L.; Hanley, H.J.M.; Cezairliyan, A.

    1986-03-01

    Using the technique of photon correlation spectroscopy we have measured the decay rate of critical fluctuations in mixtures of ethane and carbon dioxide of various compositions including a near-azeotropic mixture. Our experimental data indicate that there is only one dominant mode of fluctuations and the decay rate is well described by the predictions of the mode-coupling theory with the exponent v=0.63 for all compositions. The decay rate, its background contributions, the shear viscosity, and the correlation length for the mixtures appear to interpolate simply between those of ethane and carbon dioxide.

  13. Study on Exploration of Azeotropic Point of Pb-Sb Alloys by Vacuum Distillation and Ab Initio Molecular Dynamic Simulation

    Science.gov (United States)

    Song, Bingyi; Jiang, Wenlong; Yang, Bin; Chen, Xiumin; Xu, Baoqiang; Kong, Lingxin; Liu, Dachun; Dai, Yongnian

    2016-10-01

    The possibility of the separation of Pb-Sb alloys by vacuum distillation was investigated theoretically. The results show that Pb and Sb can be separated by vacuum distillation. However, the experimental results show that vacuum distillation technique does not provide clear separation. According to the literature, Pb-Sb alloys belong to azeotropic compounds under some certain temperature; the experiment and computer simulation were carried out based on the exceptional condition so as to analyze the reason from the experiment and microstructure of Pb-Sb alloys perspective. The separation of Pb-Sb alloys by vacuum distillation was experimentally carried out to probe the azeotropic point. Also, the functions, such as partial radial distributions functions, the structure factor, mean square displacement, and the density of state, were calculated by ab-initio molecular dynamics for the representation of the structure and properties of Pb-Sb alloys with different composition of Sb. The experimental results indicate that there exists common volatilization for Pb-Sb alloys when Sb content is 16.5 wt pct. On the other hand, the calculation results show that there is an intense interaction between Pb and Sb when Sb content is 22 wt pct, which supports the experimental results although Sb content is slightly deviation.

  14. SIMULATION OF NON-AZEOTROPIC REFRIGERANT MIXTURES FOR USE IN A DUAL-CIRCUIT REFRIGERATOR/FREEZER WITH COUNTERCURRENT HEAT EXCHANGES

    Science.gov (United States)

    The paper discusses a refrigerator/freezer (RF) system that has two complete and independent refrigeration cycles for the two compartments. It uses a non-azeotropic refrigerant mixture (NARM) in each cycle and countercurrent heat exchangers throughout. This RF is housed in a stan...

  15. Separación de la Mezcla Azeotrópica Acetona-Metanol con Cloruro de Litio Separation of an Azeotropic Acetone - Methanol Mixture Using Lithium Chloride

    Directory of Open Access Journals (Sweden)

    F. Anguebes-Franseschi

    2004-01-01

    Full Text Available Se ha determinado el efecto que tiene el cloruro de litio usado como agente extractivo para separar la mezcla azeotrópica acetona-metanol. La metodología establece la preparación de dos mezclas con diferentes concentraciones másicas de acetona-metanol, por debajo del punto azeotrópico: 85-15% y 75- 25%. En cada destilación realizada, se dosificó cloruro de litio a diferentes concentraciones para determinar el efecto de éste sobre la concentración de las mezclas y el punto azeotrópico. Los resultados determinan que a una concentración de 2.3 moles de cloruro de litio por kilogramo de solución, se obtiene el mayor efecto sobre el punto azeotrópico, considerando la manipulación del reflujo y la concentración de la sal. Se concluyó que es posible separar esta mezcla azeotrópica usando cloruro de litio como agente extractivoThe effect of lithium chloride when used as an extractive agent for separating the azeotropic mixture composed of acetone and methanol, was determined. The methodology included the preparation of two mixtures with different acetone-methanol mass concentrations, below the azeotropic point: 85-15% and 75-25%. For each distillation carried out, lithium chloride was added in different measured dosages to determine its effect on the composition of the mixtures and the azeotropic point. The results suggested that a concentration of 2.3 moles of lithium chloride per kg of solution produced the greatest effect on the azeotropic point, considering the reflux manipulation and salt concentration. It was concluded that it is possible to separate this azeotropic mixture using lithium chloride as an extractive agent

  16. A Comparison of delO18 Composition of Water Extracted from Suction Lysimeters, Centrifugation, and Azeotropic Distillation

    Science.gov (United States)

    Figueroa, A.; Tindall, J. A.; Friedel, M. J.

    2005-12-01

    Concentration of delO18 in water samples extracted by suction lysimeters is compared to samples obtained by methods of centrifugation and azeotropic distillation. Intact soil cores (30 cm diameter by 40 cm height) were extracted from two different sites. Site 1 was rapid infiltration basin number 50, near Altamonte Springs in Seminole County, Florida on properties belonging to the Walt Disney World Resort Complex. Site 2 was the Missouri Management System Evaluation Area (MSEA) near Centralia in Boone County, Missouri. The delO18 water was analyzed on a mass spectrophotometer. Potassium Bromide (KBr) was also used as a tracer and analyzed by ion chromatography. A portion of the data obtained was modeled using CXTFIT. Water collected by centrifugation and azeotropic distillation data were about 2-5% more negative than that collected by suction lysimeter values from the Florida (sandy) soil and about 5-7 % more negative from the Missouri (well structured clay) soil. Results indicate that the majority of soil water in well structured soil is strongly bound to soil grain surfaces and is not easily sampled by suction lysimeters. Also, it is plausible that evaporation caused some delO18 enrichment in the suction lysimeters. Suction lysimeters preferentially sampled water held at lower matric potentials, which may not represent total soil water. In cases where a sufficient volume of water has passed through the soil profile and displaced all previous pore water, suction lysimeters will however collect a representative sample of all the water at that depth interval. It is suggested that for stable isotope studies monitoring precipitation and soil water, suction lysimeters be installed at shallow depths (10 cm). Samples should also be coordinated with precipitation events. The CXTFIT program worked well for Florida soils (a more homogeneous sand), but gave poor performance for Missouri soils (well structured clays) except for deeper depths where clay structure was less

  17. Study on Separation of Glycol and 1,2-Propanediol With Heterogeneous Azeotropic Distillation%非均相共沸精馏分离乙二醇及1,2-丙二醇的研究

    Institute of Scientific and Technical Information of China (English)

    牛玉锋; 刘振华; 乔凯; 陈明

    2011-01-01

    It is difficult to separate glycol and 1,2-propanediol with conventional distillation methods because they have similar boiling point .In this paper, the heterogeneous azeotropic distillation was used to separate glycol and 1,2-propanediol with ethylbenzene, mixed xylene and cumene as azeotropic agent,respectively. Combining with the selectivity of azeotropic agent and the azeotropic point of azeotropic agent, suitable azeotropic agent was determined. The experiment results show that the mixed xylene is a good entrainer because it can improve volatility of glycol and 1,2-propanediol.%由于乙二醇及1,2-丙二醇的沸点相近,采用常规精馏方法难以分离。本文通过非均相共沸精馏的方法采用乙苯、混合二甲苯、异丙苯三种共沸剂进行实验,结合共沸剂的选择性和共沸物的共沸点来确定共沸剂。通过实验结果分析发现混合二甲苯能明显提高乙二醇及1,2-丙二醇的挥发度,是分离乙二醇及1,2-丙二醇良好的共沸剂。

  18. Preparation of nano-sized Al2O3-2SiO2 powder by sol-gel plus azeotropic distillation method

    Institute of Scientific and Technical Information of China (English)

    Guangjian Zheng; Xuemin Cui; Weipeng Zhang; Zhangfa Tong; Feng Li

    2012-01-01

    Nano-sized amorphous Al2O3-2SiO2 powder was prepared by a sol-gel method coupled with azeotropic distillation.The structure of the powder was investigated by DTS,BET,TEM,FT-IR,TG-DTA and XRD,showing that n-butanol azeotropic distillation could effectively remove water from the aluminosilicate gels and prevent the formation of hard agglomerates in the drying process.The average particle diameter of the powder was about 70 nm.The largest BET specific surface area of the powder was 669 m2/g.To examine the alkali-activation reactivity of the powder,alkali-activation tests were performed with the powder reacting with sodium silicate solution.The synthetic powder was found to be highly reactive.

  19. Efficiency of methods for Karl Fischer determination of water in oils based on oven evaporation and azeotropic distillation.

    Science.gov (United States)

    Larsson, William; Jalbert, Jocelyn; Gilbert, Roland; Cedergren, Anders

    2003-03-15

    The efficiency of azeotropic distillation and oven evaporation techniques for trace determination of water in oils has recently been questioned by the National Institute of Standards and Technology (NIST), on the basis of measurements of the residual water found after the extraction step. The results were obtained by volumetric Karl Fischer (KF) titration in a medium containing a large excess of chloroform (> or = 65%), a proposed prerequisite to ensure complete release of water from the oil matrix. In this work, the extent of this residual water was studied by means of a direct zero-current potentiometric technique using a KF medium containing more than 80% chloroform, which is well above the concentration recommended by NIST. A procedure is described that makes it possible to correct the results for dilution errors as well as for chemical interference effects caused by the oil matrix. The corrected values were found to be in the range of 0.6-1.5 ppm, which should be compared with the 12-34 ppm (uncorrected values) reported by NIST for the same oils. From this, it is concluded that the volumetric KF method used by NIST gives results that are much too high.

  20. Evaluation of non-azeotropic mixtures containing HFOs as potential refrigerants in refrigeration and high-temperature heat pump systems

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    With the increasing environmental concern on global warming, hydrofluoro-olefin (HFOs), possessing low GWP, has attracted great attention of many researchers recently. In this study, non-azeotropic mixtures composed of HFOs (HFO-1234yf, HFO-1234ze(z), HFO-1234ze(e) and HFO-1234zf) are developed to substitute for HFC-134a and CFC-114 in air-conditioning and high-temperature heat pump systems, respectively. The cycle performances were evaluated by an improved theoretical cy-cle evaluation methodology. The results showed that all the mixtures proposed herein were favorable refrigerants with excel-lent thermodynamic cycle performances. M1A presented lower discharge temperature and pressure ratio and higher COPc than that of HFC-134a. The volumetric cooling capacity was similar to HFC-134a. It can be served as a good environmentally friendly alternative to replace HFC-134a. M3H delivered similar discharge temperature as CFC-114 did. And the COPh was 3% higher. It exhibits excellent cycle performance in high-temperature heat pump and is a promising refrigerant to substitute for CFC-114. And the gliding temperature differences enable them to exhibit better coefficient of performance by matching the sink/source temperature in practice. Because the toxicity, flammability and other properties are not investigated in detail, ex-tensive toxicity and flammability testing needs to be conducted before they are used in a particular application.

  1. 共沸精馏分离乙醇-异丙醇%Separation of ethanol-isopropanol binary mixture by azeotropic distillation

    Institute of Scientific and Technical Information of China (English)

    张鸾; 朱宏吉; 白鹏

    2012-01-01

    为了分离乙醇-异丙醇混合物,研究了共沸精馏在乙醇-异丙醇物系中的应用。根据共沸剂的选取原则选定出1-己烯作为共沸精馏分离乙醇-异丙醇混合物的共沸剂,使用ASPEN模拟软件模拟连续和间歇共沸精馏分离乙醇-异丙醇工艺流程,并通过间歇共沸精馏实验考察了所选共沸剂的分离效果。结果表明:使用1-己烯作为共沸剂能成功的分离乙醇-异丙醇混合物;采用有30块理论板的填料塔,回流比为25,共沸剂1-己烯与乙醇的质量比为4∶1,塔釜异丙醇的质量分数达到99.77%。%Azeotropic distillaition was used to separate ethanol-isopropanol mixture.According to principles of the selection of entrainer,1-hexene was selected for the separation.Aspen plus software was used to simulate continuous and batch azeotropic distillation flow process.In addition,the effectiveness of the selected entrainer was investigated by the batch azeotropic distillation experiment.The results showed that 1-hexene can be a successful entrainer to separate the ethanol-isopropanol mixture.The separation experiment of ethanol-isopropanol mixture by batch azeotropic distillation was carried out in a packed column with 30 theoretical plates.The reflux ratio was 25,and the 1-hexene and ethanol mass ratio was 4∶1.The product mass fraction of isopropanol reached 99.77%.

  2. 溴丙烷/正己烷共沸物清洗剂的制备和性能%Preparation and cleaning performance of bromopropane/n-hexane azeotropic cleaning agent

    Institute of Scientific and Technical Information of China (English)

    杨昌炎; 孟庆岭; 丁一刚; 王超; 沈琼璐; 黄晨; 夏刚

    2012-01-01

    常压蒸馏制备二元恒沸混合物溴丙烷/正己烷,并作恒沸物与标样的气相色谱分析.拟合标样两组分体积比与峰面积比的函数关系,进而计算出恒沸物两组分的体积比为89.9∶10.1.进行外观、物理稳定性、相对密度、黏度、残留量、挥发速度、pH值、绝缘电阻值、含水质量分数、表面张力、污垢洗净率等性能测定,结果显示各项性能均达到了带电清洗剂的要求,可以作为新型带电清洗剂推广.%The azeotropes bromopropane/n-hexane was prepared by atmospheric distillation, and the azeotrope and samples were analyzed by gas chromatography. The functional relationship between the volume ratio and peak area ratio of the samples was fitted. As a result, the volume ratio of two components of azeotrope was calculated as 89. 9: 10. 1. All kinds of the cleaning performance of the azeotrope cleaning agent such as appearance, physical stability, relative density, viscosity, violating speed, pH value, insulation resistance, water content, surface tention and wash-ratio were measured. The results show that all the performances meet the requirements of the on-line cleaning agent, and the azeotrope bromopropane/n-hexane can be widely applied as new on-line cleaning agent.

  3. Two-Phase Flow and Energy Transfer of a Non-Azeotropic Mixture, R-407c, in a Micro-Fin Tube

    Science.gov (United States)

    Liu, Xin

    1996-11-01

    This study is to determine experimentally the two-phase flow and energy transfer characteristics of a non-azeotropic refrigerant mixture, R-407c (nominal composition: 23% R-32, 25% R-125, and 52% R-134a). R-407c is a fluid with zero ozone depletion potential and one of several alternatives to currently widely used pure refrigerant HCFC-22. As a non-azeotrope, R-407c has distinctly different characteristics from pure fluids. The phase change of a non-azeotrope under constant pressure does not proceed at a constant temperature but rather over a range of temperature. In addition, the momentum, energy transfer, and mass transfer processes are closely linked. The vapor-liquid interfacial mass transfer rate limits the evaporation or condensation rate, and in turns limits the energy transfer rate. The experiments are conducted in a test apparatus with a fluid sampling port to monitor the composition change of the mixture. The test section consists of six horizontal identical passes, constructed as double tube heat exchangers. Each pass is about 2.2 m long and are connected in order by 7.6 cm radius U-bends. The heated or cooled section of each pass is shorter than the pass length and is 1.8 meter long. The inner (mixture) tube of the test section is a nominal 3/8" inch (9.5 mm) copper tube of 0.348 mm wall thickness with 72 axial fins of 0.185 mm height on its inner surface. The apex angle of the fins is 15 deg. and the helix angle is 0. The annulus-side water, serving as heat source (evaporating mode) or heat sink (condensing mode), flows through the annular space between inner and outer tubes. The tests are conducted at 100 deg F dew point temperature and mass flux from 192,000 to 818,000 lb/hr-ft^2 for condensing, and 50 deg F dew point and mass flux from 70,000 to 394,000 lb/hr-ft^2 for evaporating. The experimental results show that, compared to R-22, two-phase flow frictional pressure gradients of R-407c are about 10% less than R-22. Due to the mass transfer

  4. Trials to improve the colour of colour fixed cottonseed oil using sodium oleate and sodium stearate in the absence and presence of azeotropic extract of cottonseed meal

    Directory of Open Access Journals (Sweden)

    Yousef, Elham A. A.

    1998-04-01

    Full Text Available The effectiveness of two additives, namely, laboratory prepared sodium oleate and sodium stearate to improve the colour of colour fixed cottonseed oil was studied. Also the presence of the azeotropic extract of cottonseed meal together with 5% Na oleate or 10%Na stearate was taken In consideration. Improvement in the colour index of most treated refined and bleached oil samples is observed. This is confirmed with the reduction of gossypol contents of the refined and bleached treated oil samples compared with the untreated oil sample.

    Se estudió la eficacia de dos aditivos, a saber, oleato sódico y estearato sódico preparados en laboratorio para mejorar el color del aceite de semilla de algodón con color fijado. También se tuvo en consideración la presencia de extracto azeotrópico de harina de semilla de algodón junto con oleato sódico al 50% o estearato sódico al 10%. Se observó la mejora en el índice de color de la mayoría de las muestras de aceite decolorado y refinado tratado. Esto está confirmado con la reducción de los contenidos en gosipol de las muestras de aceites refinados y decolorados tratados comparado con la muestra de aceite no tratado.

  5. Preparation of Highly Dispersed Antimony-doped Tin Oxide Nano-powder via Ion-exchange Hydrolysis of SnCl4 and SbCl3 and Azeotropic Drying

    Institute of Scientific and Technical Information of China (English)

    YANG Fen; ZHANG Xue-jun; TIAN Fang; WU Xu; GAN Fu-xing

    2007-01-01

    Antimony-doped tin hydroxide colloid precipitates have been synthesized by hydrolysis of SnCl4 and SbCl3 using: (1) an ion-exchange hydrolysis to remove chlorine ions, and (2) isoamyl acetate as an azeotropic solvent to obviate water. The obtained dried powder is of high dispersivity without any need for further grinding. The size and dispersivity of the final particles are investigated with the aid of TG-DTA, BET, XRD and TEM. After having calcined, the antimony-doped tin oxide nanopowder possesses a tetragonal rutile structure with high dispersivity, uniform particles and low hard agglomeration.

  6. New valorization process for refinery slop oil and oily wastes by hetero-azeotropic distillation; Nouveau procede de valorisation des ''slops'' de raffineries et dechets huileux par distillation heteroazeotropique

    Energy Technology Data Exchange (ETDEWEB)

    Lucena, E. [Universidad Centrocidental Lisandro Alvarado, Decanato de Ingenieria Civil, Lab. de Calidad Ambiental, Barquisimeto (Venezuela); Verdun, P.; Aurelle, Y. [Institut National des Sciences Appliquees (INSA), Dept. de Genie des Procedes Industriels, Lab. d' Ingenierie des Procedes de l' Environnement (EA 833), 31 - Toulouse (France); Secq, A. [TotalFinaElf, Centre de Recherche Gonfreville, Dept. Procedes et Raffinage, 76 - Harfleur (France)

    2003-07-01

    The petroleum exploitation, at the production level as well as at the refining process, produces important amounts of oily wastes that have a 'mayonnaise-like' mud appearance, called slops oils. These slop oils are very stable inverse water emulsions in crude oil containing solid sediments. The proportion of each of the three phases is very variable from one slop oil to another, however, the watery phase is often majority, from 40 to 80% of the mixture. The slop oils, up to the present, constitute a waste with very little or no valorization at all. The main processing methods used today, incineration and centrifugation, do not allow carrying out a total separation of the present liquid (water and oil) and solid phases. Moreover, they are not optimal from the economic and ecological point of view as well as from the energetic point of view. The processing technique of the petroleum slop oils proposed in this study is based on distillation principles, specifically on the hetero-azeotropic distillation. The method consists in forming a hetero-azeotropic mixture adding a carrier (kerosene) to the slop oil, then distilling the mixture and extracting a distillate, water and carrier, causing simultaneously a destabilization of the emulsion. By simple condensation of the distillate, the water is separated from the kerosene, which can be recycled. After distillation, the obtained dehydrated oil remains can be valorized in the distillation units of the refinery. This study points out the relevance of the proposed method, which presents the advantages of obtaining a complete separation of the phases and without generating any remainder sub-product from it. Moreover, it perfectly fits in the processing logic of any oil refinery. (authors)

  7. Study on separation of chlorobenzene and acetic acid azeotrope by distillation-crystallization hybrid separation process%蒸馏-结晶耦合工艺分离乙酸-氯苯共沸体系的研究

    Institute of Scientific and Technical Information of China (English)

    宋闯

    2015-01-01

    本文主要对蒸馏-结晶耦合工艺分离共沸体系进行研究。以乙酸-氯苯为研究对象,对耦合工艺的原理和实验装置进行研究设计。通过对回流比,结晶终温,降温速率和发汗等工艺条件的考察,得出蒸馏-结晶耦合工艺分离乙酸-氯苯共沸体系的最佳条件,即:最佳回流比为2,结晶终温为-6℃,降温速率为0.2618℃/min.,发汗时间为2.5h。%This paper mainly studies that binary azeotrope system has been separated by the distillation-crystallization hybrid separa-tion process .Taken chlorobenzene and acetic acid for researching objects,the principle of hybrid separation process was studied and the experimental equipment was designed.By studing of the reflux ratio, final crystallization temperatures,the cooling rate and sweating, opti-mum conditions of separating chlorobenzene-acetic acid azeotrope by distillation-crystallization hybrid separation process were determined. The best reflux ratio was 2, the final crystallization temperature was -6℃, the cooling rate was 0.2618℃/min, sweating time was 2.5h.

  8. 异丙醇-水共沸体系的连续萃取精馏过程模拟%Simulation of Isopropanol-Water Azeotrope with Continuous Extractive Distillation Process

    Institute of Scientific and Technical Information of China (English)

    田茂伦; 黄禹; 吕帮怀; 王克良; 连明磊; 刘汉国; 杜廷召

    2016-01-01

    本文基于化工模拟软件Aspen Plus,对异丙醇-水共沸体系的连续萃取精馏工艺进行模拟与优化。通过绘制拟二元汽液平衡相图,筛选出合适的萃取剂为二甲基亚砜(DMSO)。确定了双塔连续萃取精馏的工艺流程,结合Sensitivity灵敏度分析的结果得到最佳工艺方案。对于处理流量100kmol/h的异丙醇-水共沸溶液,精馏塔具有23块塔板时,原料进料位置在第17块塔板,萃取液进料位置在第3块塔板,摩尔回流比为2.4,溶剂比(萃取剂对原料的摩尔比)为1.6,异丙醇摩尔分数可达99.80%,萃取剂回收塔塔顶水的纯度达到99.58%;二甲基亚砜(DMSO)的循环补充量为0.0288kmol/h,回收率可达99.982%。模拟和优化的结果为工业化设计和操作提供了理论依据和设计参考。%This paper simulates and optimizes the continuous extractive distillation process for isopropanol-water azeotropic system by using Aspen Plus V7.3. By the pseudo-binary phase diagram,DMSO is selected as a suitable extractant. The process of continuous extractive distillation with two columns is confirmed. The optimal technological scheme is obtained by sensitivity analysis tool of Aspen Plus V7.3,as follows: with 100kmol/h of isopropanol-water azeotropic solution,the number of theory stages is 23,the mixture feed stage is 17st,the solvent feed stage is 3rd, the reflux ratio is 2.4,and the solvent ratio is 1.6. Under the technological condition: the separation effect of iso-propanol is up to 99.80%,the purity of water of the extractant-recovery column is 99.58%; Cyclic supplementation of DMSO is 0.0288 kmol/h,and the recovery rate of triglycol is up to 99.982%. The results are useful for the design and operation of continuous extractive distillation process for isopropanol-water azeotropic system.

  9. 间歇精馏分子异丙醇-水二元共沸物的模拟%Simulation of Separating Isopropanol-Water Azeotropic Mixture Batch Extractive Distillation

    Institute of Scientific and Technical Information of China (English)

    黄路; 叶青; 孙文雅

    2011-01-01

    Batch extractive distillation for isopropanol-water mixture was simulated and optimized. Simulation of batch extractive distillation was executed by BatchFrac module of Aspen Plus simulation software, based on UNIFAC model, glycol as the extractant. The effect on the process of different operation parameters was also studied, such as solvent ratio, mole reflux ratio, solvent feeding location, solvent feeding temperature. Sensitivity analysis was also performed to optimize the operation parameters. The simulation results showed that it was possible to separate isopropanol-water azeotropic mixture by batch extractive distillation using glycol as extractant. When isopropanol - water azeotropic mixture was l00kmol and stage numbers of extractive distillation column was 20, solvent feeding location was 3, solvent feeding temperature was 80℃, mole reflux ratio was 5 and solvent ratio was 2, the mass fraction of isopropanol at the column top could reach 0. 998. The results of simulation and optimization supply certain guidance for the deep application of batch extractive distillation in industry.%以乙二醇为溶剂,使用Aspen Plus化工模拟软件中的BatchFrac模块,基于UNIFAC模型,对异丙醇-水二元共沸物的间歇萃取精馏过程进行间歇萃取精馏模拟,研究了不同操作参数(如溶剂比、回流比、溶剂进料位置、溶剂进料温度等)对整个精馏过程的影响,对各工艺参数进行了分析与优化.结果表明,对于处理量为100kmol的异丙醇-水溶液,精馏塔具有20块塔板,溶剂比为2,回流比为5,溶剂进料位置在第3块塔板,溶剂进料温度为80℃时,塔顶异丙醇质量分数可达0.998,收率可达0.978.

  10. 异丙醇-环己烷萃取精馏过程模拟与优化%Simulation and Optimization of Extractive Distillation for Isopropanol-Cyclohexane Azeotropic Mixture

    Institute of Scientific and Technical Information of China (English)

    王婧娴; 乔建军; 梁金华; 白鹏

    2013-01-01

    Extractive distillation for isopropanol-cyclohexane azeotropic mixture was simulated and optimized. Simulation of extractive distillation was executed by RadFrac module of Aspen Plus simulation software using NRTL model and furfural as solvent. Sensitivity analysis was also performed to optimize the operation parameters. The simulation results show that its possible to separate isopropanol-cyclohexane a-zeotropic mixture by extractive distillation using furfural as solvent. The optimum operation parameters were as follows: in extractive distillation column, ideal stage number is 30, number of feed stage is 26, number of solvent stage is 12, mole reflux ratio is 1. 8 and ratio of solvent to feed is 3:1 ;in solvent recovery column, ideal stage number is 15, number of feed stage is 10, molar reflux ratio is 1. Under the optimized parameters, mass fraction of cyclohexane can reach 99. 74% and mass fraction of isopropanol can reach 99. 61% . The results of simulation and optimization will provide fundamental guide for the industrialization design and production.%利用化工流程模拟软件Aspen Plus对异丙醇-环己烷共沸物系的双塔连续萃取精馏过程进行了模拟计算与优化.首先根据溶剂相似相溶原理,先初选出糠醛和硝基苯作为备选溶剂,再通过汽液平衡试验及ChemCAD模拟筛选,确定糠醛为最适宜溶剂,选择NRTL模型作为物性方法,使用RadFrac模块进行模拟计算,并利用灵敏度分析模块对各工艺参数进行优化.结果表明,最适宜工艺方案为:萃取精馏塔理论塔板数为30,原料在第26块板进料,溶剂在第12块板进料,物质的量回流比为1.8,溶剂质量比为3∶1;溶剂回收塔理论板数为15,进料位置在第10块板,物质的量回流比为1.0.分离效果可达到环己烷质量分数为99.74%,异丙醇质量分数为99.61%.模拟和优化结果为分离过程的优化操作和设计提供了依据.

  11. Discussion on Determination Methods of Impurity Content in Acetonitrile at the Top of Vacuum Azeotropic Tower%减压共沸塔顶乙腈杂质含量测定方法探讨

    Institute of Scientific and Technical Information of China (English)

    崔凤艳; 王慧

    2013-01-01

      建立气相色谱法测定乙腈装置减压共沸塔顶(T202顶)粗乙腈杂质含量的分析方法。采用DB-FFAP毛细管色谱柱、氢火焰检测器,带范围校正归一化法定量。通过实验选择最佳分析操作条件,成功分析出粗乙腈中微量丙烯腈、丙酮、唑、丙腈等杂质含量。解决了填充柱在分析此样品时,主要杂质丙烯腈与未知杂质色噁谱峰重叠的问题。测定的相对标准偏差均小于5.0%,各组分加标回收率在97%~102%之间,能满足分析要求。%  A gas chromatography analysis method for determining impurity content in acetonitrile at the top of vacuum azeotropic tower was established through adopting capillary column DB-FFAP, flame ionization detector and correcting the area with normalization. The best analysis conditions were obtained through experiments, and impurity content in acetonitrile was successfully analyzed, such as trace acrylonitrile,acetone , oxazole , propionitrile and so on. The problem of overlapping chromatographic peaks in chromatography analysis with the packed column was solved. The relative standard deviation was less than 5.0%, the recovery rates of components were in the range of 97%~102%,so the method can satisfy the analysis requirement.

  12. The Simulation and Optimization of Toluene-Ethanol Azeotrope With Extractive Distillation%甲苯—乙醇共沸体系的萃取精馏模拟与优化

    Institute of Scientific and Technical Information of China (English)

    侯涛; 高晓新

    2012-01-01

    利用Aspen Plus化工模拟流程软件对甲苯—乙醇共沸体系进行了萃取精馏模拟分离研究.应用Flash 2模块来筛选出萃取精馏的适宜溶剂为正丁苯.确定了萃取精馏的工艺流程,并且通过灵敏度分析模块分别考查了萃取精馏塔和溶剂回收塔的进料板位置、回流比以及溶剂比对分离效果的影响.当溶剂质量比为2.2时,产品乙醇的质量分数可达99.9%,甲苯可达99.5%,溶剂回收率约为99.5%.%Toluene - ethanol azeotropic system was separated of the simulation and studied using Aspen Plus chemical simulation software. Butyl benzene was selected as suitable solvent for extractive distillation applying Flash 2 module. Process of extractive distillation was confirmed, and feed plate location, reflux ratio and solvent ratio of extractive distillation tower and solvent recovery tower on separation effect were researched using sensitivity analysis module. When the solvent ratio was 2. 2, the product of ethanol mass fractiont is 99, 9%,and toluene is 99. 5% , solvent recovery rate is approximately 99, 5%.

  13. 醋酸-对二甲苯-水体系共沸精馏的模拟分析%Simulation analysis on azeotropic distillation of acetic acid-p-xylene-water system

    Institute of Scientific and Technical Information of China (English)

    周永兵; 刘建新; 陈韶辉

    2011-01-01

    采用Aspen Plus11.1化工流程模拟软件,对扬子石油化工有限公司化工厂精对苯二甲酸(PTA)装置的溶剂脱水塔生产过程进行了模拟计算,采用NRTL-HOC热力学计算模型,并进行热力学参数修正,通过调整塔板数、热负荷、进料位置、操作压力、对二甲苯(PX)采出位置等操作参数,得出各塔的最佳工艺条件.在最佳工艺条件下,分析了此分离过程的能耗问题.模拟结果表明,溶剂脱水塔分离得到的醋酸、水、PX均能达到产品质量要求,工艺流程合理、可靠.%The design and optimization are carried out for the separation process of solvent dehydration column in PTA plant by the chemical simulation software of Aspen 11. 1 model. Non- random two liquids hayden-Oconnell( NRTL-HOC) thermodynamic calculation model is used and some what thermodynamics parameters are modified. However, theoretical plate number,heat duty,feed location,operation pressure and discharging plate of p-xylene are adjusted in order to obtain optimal results for azeotropic distillation. Under the optimum conditions, the energy consumption in the distillation is analyzed. The results demonstrate that the acetic acid,P-xylene and water from the separation process of solvent dehydration column can meet with the quality requirement. The process is reasonable and reliable, and has some reference significance for engineering and operation.

  14. 微通道内非共沸混合制冷剂的流动沸腾特性%Investigation on flow boiling heat transfer of non-azeotropic refrigerant mixture in microchannel

    Institute of Scientific and Technical Information of China (English)

    吕凤勇; 马虎根; 何红萍; 齐鲁山

    2012-01-01

    采用了3种不同组分比例的R32/R134a工质在0.86 mm的微通道中进行了传热特性和阻力特性的实验研究,考察了非共沸工质不同组分比例对微通道换热特性的影响。实验结果表明:在组分质量分数比为35%/65%时,核态沸腾在小干度下换热效果最好;干度较大时,组分比例对换热的影响效果降低。在大质量流量下传热阻力效应的影响不再明显。在压降方面,组分比为15%/85%的相对压降最大,其它两种组分的压降较小。%The heat transfer characteristics in microchannel 0.86 mm in diameter for refrigerant mixture R32/R134a with three different mass proportions were studied and the effect of non-azeotropic working media with different mass proportions on heart transfer in the microchannel was investigated.The experiment result showed that when mass proportion was 35%/65%,flow boiling heat transfer was the best at low dryness fraction,while the effect of mass proportion on heat transfer was not obvious at high dryness fraction.Heat transfer resistance effect was not obvious at a high mass flux.Pressure drop was the largest when mass proportion was 15%/85%,and for the other two mass proportions,25%/75% and 35%/65%,pressure drop was relatively smaller.

  15. Separation of binary azeotrope ethanol-dimethyl carbonate by extractive distillation%萃取精馏分离碳酸二甲酯-乙醇二元共沸物

    Institute of Scientific and Technical Information of China (English)

    董营; 肖颖; 黄耀东; 白鹏

    2013-01-01

    Vapor-liquid equilibrium data of the systems were measured at 101.3 kPa with ethanol-DMC, DMC-furfural and ethanol-DMC-furfural in a solvent ratio of 1 : 1. It was shown that furfural can enlarge the relative volatility of ethanol and DMC, and the azeotropic point disappeared when mole fraction of furfural reached 0.25, indicating the feasibility of separating the ethanol-DMC mixture using extractive distillation with furfural as the solvent. Aspen Plus software was used to simulate the continuous extractive distillation processes of ethanol-DMC separation, and the single-column continuous extractive distillation process was preferred than the double-column process.%测定了101.3 kPa下乙醇-碳酸二甲酯(DMC)和DMC-糠醛二元体系的汽液平衡数据,以及乙醇-DMC-糠醛体系在溶剂比为1:1时的三元汽液平衡数据.结果表明,糠醛的加入可以改变乙醇和DMC的相对挥发度,并且当糠醛的摩尔分数大于0.25时,乙醇-DMC二元物系的共沸点消失.因此,可以采用萃取精馏的方法以糠醛为溶剂分离乙醇和DMC的混合物.采用Aspen Plus软件对连续萃取精馏分离乙醇-DMC共沸物的过程进行了模拟.结果表明,单塔带侧线采出的操作方式比双塔操作方式更有优势.

  16. SiO2气凝胶的溶胶-凝胶/共沸蒸馏法制备及表征%Preparation of SiO2 Aerogel by Combining Sol-gel and Azeotropic Distillation Processes and Characterization

    Institute of Scientific and Technical Information of China (English)

    岳瑞丽; 张志建; 马荣; 关怀民; 童跃进

    2011-01-01

    以工业水玻璃为硅源,采用溶胶-凝胶和共沸蒸馏的方法在常压下制备SiO2气凝胶,研究制备条件对SiO2气凝胶性能的影响.结果表明,当溶液体系的pH值为4.5,添加2 mL甲酰胺作为干燥控制化学添加剂(DCCA),并以正丁醇与凝胶中的水为共沸蒸发介质时,所制备的SiO2气凝胶具有典型的气凝胶结构特征,经分析SiO2气凝胶的密度、比表面积、孔容及孔径分布分别为0.19 g/cm3、689 m2/g、2.1 mL/g和8.0 nm.通过X射线衍射(XRD)和冷场发射扫描电镜(FESEM)对SiO2气凝胶的形貌和微观结构进行表征,SiO2气凝胶呈非晶态,其颗粒尺寸分布在100 nm左右.红外光谱(FTIR)证实了SiO2凝胶的形成.%Using cheap water-glass as silica source, the silica aerogel has been prepared via sol-gel method and azeotropic distillation process under ambient pressure. The effect of preparing conditions on the properties of the SiO2 aerogel was investigated. The optimum conditions were: pH 4.5 and 2 mL of formamide as DCCA, n-butyl alcohol/water in alcogel for azeotropic distillation medium. The bulk density, specific surface area, pore volume and pore size distribution for the resulting silica aerogel were 0. 19 g/cm3, 689 m2/g, 2. 1 mL/g and 8.0 nm, respectively. These results indicated a typical structure of the silica aerogel. The morphology and microstructure of the aerogel were observed by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The silica aerogel possess random non-crystal property. The particle size of the SiO2 aerogel was around 100 nm. The infrared spectrum (FTIR) verified the form of silica.

  17. Performance Analysis of Non-azeotropic Mixture Based on CNG Engine Waste Heat Recovery System%基于天然气发动机排气余热回收系统的非共沸混合工质性能分析

    Institute of Scientific and Technical Information of China (English)

    娄宗勇; 郭珍; 宋松松; 张红光

    2015-01-01

    针对一台车用天然气发动机排气能量的变化规律,建立了带回热器有机朗肯循环系统,对比分析了采用纯工质R245fa和非共沸混合工质R416A时,带回热器有机朗肯循环系统的净输出功率、热效率、效率和单位工质能量输出密度。结果表明,采用非共沸混合工质R416A时上述各项性能指标均优于采用纯工质R245fa。最后,构建了天然气发动机‐带回热器有机朗肯循环联合系统,采用非共沸混合工质 R416A ,分析了联合系统的热效率。结果表明,加装带回热器有机朗肯循环系统后,发动机热效率最大可提高7%。%A set of organic Rankine cycle (ORC) system with internal heat exchanger (IHE) was designed to recover exhaust energy of a compressed natural gas (CNG) engine .The net output power ,heat release efficiency ,exergy efficiency and energy output density of ORC system for R245fa and R416A organic working fluids were compared and analyzed .The results show that the performance of R416A zeotropic mixture surpasses that of R245fa .Finally ,the CNG engine and ORC combined system with IHE is built and the thermal efficiency of R416A non‐azeotropic mixture is analyzed .It is found that the thermal efficiency of engine can increase by 7% at most .

  18. Improvement of Batch Distillation Separation of Azeotropic Mixtures

    OpenAIRE

    Hegely, Laszlo

    2013-01-01

    La distillation est le procédé de séparation le plus répandu dans l'industrie chimique. Pour la séparation des mélanges azéotropiques, une méthode spéciale de distillation doit être appliquée. Le but de mon travail était d'améliorer la séparation des mélanges azéotropiques par distillation discontinue (DD). Un nouvel algorithme a été présenté pour la détermination de la séquence des produits de DD pour des mélanges multicomposants azéotropiques. Contrairement aux méthodes publiées précédemmen...

  19. Pressure swing distillation of azeotropic mixture – A simulation study

    Directory of Open Access Journals (Sweden)

    Asma Iqbal

    2016-09-01

    Full Text Available The aim of this work is to simulate a pressure-swing distillation column for the separation and purification of ethanol from the ethanol–water binary system. The choice for this system is due to the importance of the ethanol–water separation. A steady-state equilibrium-stage model based on normalised MESH equations is used to simulate pressure-swing distillation column applied for the production of ethanol. All the work has been carried out using Aspen Plus simulator, version 13.2. Among the activity coefficient models available, the WILSON-RK model with binary parameters predicted by the Aspen Plus simulator is shown to be the most accurate to correlate the experimental vapor-/liquid equilibrium (VLE data available for the ethanol–water system. The simulation has been satisfactorily carried out for a mixture of 20 mol% ethanol in water at 1 atm pressure and 90 °C with a molar flow rate of 100 kmol/h. The adjusting parameters include D/F ratio and reflux ratio of the two columns to get water purity of 99.5 mol% from the bottom of the Low Pressure Column (LPC and the ethanol purity of 99.7 mol% from the bottom of High Pressure Column (HPC.

  20. Ionic-Liquid Based Separation of Azeotropic Mixtures

    DEFF Research Database (Denmark)

    Kulajanpeng, Kusuma; Suriyapraphadilok, Uthaiporn; Gani, Rafiqul

    2014-01-01

    such as stability, toxicity, and environmental impacts of the ILs. A Hildebrand solubility parameter group contribution model for ILs is highlighted to screen the miscibility of the ILs with the target solute component which was considered as a key target property to further screen the candidates from the previous...

  1. 水-乙酸-糠醛三元体系相平衡数据关联与共沸精馏过程模拟%VLE correlation and azeotropic distillation simulation for water-acetic acid-furfural ternary system

    Institute of Scientific and Technical Information of China (English)

    孙毅; 谢清若; 韦藤幼; 童张法

    2011-01-01

    parameters obtained are accurate and reliable. The residue curve maps are important for the design and operation of heterogeneous azeotrope rectification process of water-acetic acid-furfural ternary system.

  2. Tools development for analysis and conceptual design of extractive and azeotropic distillation columns at finite reflux

    OpenAIRE

    Estupiñan Pérez, Libardo

    2012-01-01

    En este trabajo métodos cortos fueron desarrollados para el diseño conceptual de la destilación extractiva y azeotrópica. Tres diferentes casos de destilación azeotrópica y extractiva fueron estudiados: destilación azeotrópica homogénea en columnas con un alimento, destilación extractiva homogénea y destilación heterogénea en columnas con un alimento. La evaluación de la factibilidad del proceso, el cálculo de los parámetros de diseño y la mínima energía constituyen el núcleo del presente tra...

  3. Separation of ethanol/water azeotrope using compound starch-based adsorbents.

    Science.gov (United States)

    Wang, Yanhong; Gong, Chunmei; Sun, Jinsheng; Gao, Hong; Zheng, Shuai; Xu, Shimin

    2010-08-01

    Comparing breakthrough cures of five starch-based materials experimentally prepared for ethanol dehydration, a compound adsorptive agent ZSG-1 was formulated with high adsorption capacity, low energy and material cost. The selective water adsorption was conducted in a fixed-bed absorber packed with ZSG-1 to find the optimum conditions yielding 99.7 wt% anhydrous ethanol with high efficiency. The adsorption kinetics is well described by Bohart-Adams equation. The adsorption heat, Delta H(abs), was calculated to be -3.16 x 10(4)J mol(-1) from retention data by inverse gas chromatography. Results suggested that water entrapment in ZSG-1 is a exothermic and physisorption process. Also, ZSG-1 is recyclable for on-site multiple-use and then adapt for upstream fermentation process after saturation, avoiding pollution through disposal.

  4. Automated Generation of Phase Diagrams for Binary Systems with Azeotropic Behavior

    DEFF Research Database (Denmark)

    Cismondi, Martin; Michelsen, Michael Locht; Zabaloy, Marcelo S.

    2008-01-01

    In this work, we propose a computational strategy and methods for the automated calculation of complete loci of homogeneous azeotropy of binary mixtures and the related Pxy and Txy diagrams for models of the equation-of-state (EOS) type. The strategy consists of first finding the system's azeotro...

  5. Azeotropic Preparation of a "C"-Phenyl "N"-Aryl Imine: An Introductory Undergraduate Organic Chemistry Laboratory Experiment

    Science.gov (United States)

    Silverberg, Lee J.; Coyle, David J.; Cannon, Kevin C.; Mathers, Robert T.; Richards, Jeffrey A.; Tierney, John

    2016-01-01

    Imines are important in biological chemistry and as intermediates in organic synthesis. An experiment for introductory undergraduate organic chemistry is presented in which benzaldehyde was condensed with "p"-methoxyaniline in toluene to give 4-methoxy-"N"-(phenylmethylene)benzenamine. Water was removed by azeotropic…

  6. Liquid chillers with the non-azeotropic refrigerant R 407C; Fluessigkeitskuehler mit dem nicht-azeotropen Kaeltemittel R 407C

    Energy Technology Data Exchange (ETDEWEB)

    Rigot, G. [Frinotek SA/Groupe BRANCHER, Bron (France)

    1995-08-01

    R 407C can be used as supplement of R22 in liquid chillers, as far as they are specially designed for this refrigerant. This paper shows the main properties and the advantages and disadvantages of both refrigerants, for R407C the newy system of liquid chillers MODUVIS was developed. (orig.)

  7. 三元非共沸混合制冷剂热力性质算法%Algorithm for non-azeotropic ternary refrigerant mixture thermodynamic properties

    Institute of Scientific and Technical Information of China (English)

    吴献忠; 崔晓钰; 马虎根; 李美玲

    2007-01-01

    为了确保计算的精确性,文中采用PRHV与Lee-Kesler-P1ǒcker(LKP)模型相结合的方法计算混合工质汽液相平衡参数与焓、熵等热物理性质,即利用Huron-Vidal混合规则,采用立方型PR方程和过量Gibbs自由能NRTL模型相结合的PRHV模型预测相平衡参数,在此基础上,由LKP多参数状态方程计算的焓、熵等状态参数.文中验证了这种预测方法的可靠性与准确性,此方法可作为系统循环模拟计算中相平衡及热力参数的精确计算方法.

  8. Batch extractive distillation for separation of ether-isopropanol-water azeotropic system%异丙醚-异丙醇-水三元共沸物的分离

    Institute of Scientific and Technical Information of China (English)

    叶青; 黄路; 陆叶倩; 杜广耀

    2011-01-01

    以乙二醇为溶剂,对异丙醚-异丙醇-水三元共沸物采用间歇萃取精馏进行分离研究,考察了在溶剂不同进料速率、回流比、进料温度等条件下的分离情况,找到了实验条件下分离此三元共沸物的最佳条件。最佳条件为:溶剂进料位置为塔顶,回流比为2,溶剂进料速率在分离异丙醚和分离异丙醇两个阶段分别为11.4 g/min和8.08g/min,溶剂进料温度分别为70.0℃和100.0℃。在此条件下,异丙醚产品质量分数可达0.95,收率为0.985;异丙醇产品质量分数可达0.97,收率为0.968。%Batch extractive distillation for ether-isopropanol-water mixture was studied by using glycol as the extractant. The influence of solvent feeding rate, reflux ratio and solvent feeding temperature was investigated. Under the optimal operation conditions: solvent feeding location at the column top. Reflux ratio was 2, solvent feeding rate 11.4g/min in the step of isopropyl ether collection and 8.08 g/min in the step of isopropanol collection, solvent feeding temperature 70.0 ℃ in the step of isopropyl ether collection and 100.0 ℃ in the step of isopropanol collection, the mass fraction of isopropyl ether at the column top could reach 0.95 and its yield was 0.985, the mass fraction of isopropanol at the column top could reach 0.97 and its yield was 0.968.

  9. Theoretical and experimental study of integrated membrane / distillation processes for industrial applications

    NARCIS (Netherlands)

    Perez, P.

    2007-01-01

    In industrial practice the separation of an azeotropic mixture usually involves adding a third component to the distillation process to break the azeotrope. The major disadvantages of this so called azeotropic and extractive distillation are the relatively high capital and high energy costs and the

  10. 自动复叠制冷系统非共沸混合工质的换热模拟%Heat Transfer Simulation of Non-azeotropic Mixtures Automatic Cascade Refrigeration System

    Institute of Scientific and Technical Information of China (English)

    马冰奇; 陈秋燕; 张俊强

    2015-01-01

    In this paper , the cascade refrigeration system , refrigerant R22 will be replaceed with environmental working medium R410a.The heat transfer of the R410a/R23/R14 in the evaporation temperature of -110℃is sim-ulated by Ansys simulation , the working pairs according to the maximum separation rate are selected .Finnally calcu-late the feasibility of using simulation R410a instead of R22.%本文将复叠式制冷系统中制冷剂R22换成环保工质R410a,并且应用Ansys仿真模拟自动复叠制冷系统的蒸发温度为-110℃时非共沸混合工质R410a/R23/R14的换热情况,筛选出最大分离率对应的工质对及其配比,验证R410a代替R22的可行性。

  11. R407c泄漏对制冷量及性能系数的影响%Thermodynamic Analysis on Leakage of Non-Azeotropic Refrigerant R 407c

    Institute of Scientific and Technical Information of China (English)

    耿玮; 朱玉群; 陈滢

    2001-01-01

    以PR状态方程为基础建立了R407c热力性质推 算的计算模型,并以此为工具展开R407c泄漏的热力学分析,得到R407c正常泄漏所 导致的冷量不足及性能系数的下降均在5%以内。%The modeling on calculation of R407c thermodynamic properties is est up on the b asis of PR equation of state, and thermodynamic analysis is improved, and the dr opping value of COP and refrigerating capacity which is below 5% during the normal leakage is got.

  12. 异丙醚-异丙醇-水三元共沸物的Aspen Plus分离模拟%Simulation of Batch Extractive Distillation on Separation Ether-Isopropanol-Water Azeotropic System

    Institute of Scientific and Technical Information of China (English)

    黄路; 叶青

    2010-01-01

    以乙二醇为溶剂,使用Aspen Plus化工模拟软件中的BatchFrac模块,基于UNIFAC模型,对异丙醚-异丙醇-水三元共沸物的间歇萃取精馏过程进行间歇萃取精馏模拟,研究了不同操作参数(如溶剂比、回流比、溶剂进料位置、溶剂进料温度等)对整个精馏过程的影响,对各工艺参数进行了分析与优化.结果表明,对于处理量为100 kmol的异丙醚-异丙醇-水溶液,精馏塔具有16块塔板时,溶剂进料位置在第3块塔板,溶剂进料温度为60℃,异丙醚收集阶段回流比为5,溶剂比为1.72∶1,异丙醇收集阶段回流比为5,溶剂比为0.63∶1,塔顶异丙醚质量分数可达0.996,异丙醇质量分数可达0.978.

  13. 间歇萃取精馏分离甲醇-丙酮共沸物的研究%Separation of Methanol-Acetone Azeotropic Mixtures by Batch Extractive Distillation

    Institute of Scientific and Technical Information of China (English)

    范国枝; 邹兵; 郭钰; 何君

    2009-01-01

    在常规间歇萃取精馏实验装置中,研究了以水为萃取剂间歇萃取精馏分离甲醇-丙酮共沸物的过程.考察了萃取剂、回流比、全回流时间、共沸物组成、溶剂与混合物的质量比等因素对萃取精馏分离甲醇-丙酮共沸体系的影响.

  14. PREDICTION AND CALCULATION OF AZEOTROPIC’S BEHAVIOURS ON THE BASIS OF CUBIC EQUATION OF STATE

    OpenAIRE

    Троценко, А. В.

    2015-01-01

    The azeotropic binary mixtures are effective working substances for various refrigerators, including low-temperature ones. Their experimental finding and investigation is the complicated and labour-intensive problem. That problemrestrains more practical application of azeotropic mixtures in cooling systems. The problems of prediction and modeling of azeotropic behaviours with the help of two-parametric cubic equations of a state are considered. Using the maxwell line method, the conditions of...

  15. Isopropyl alcohol recovery by heteroazeotropic batch distillation

    OpenAIRE

    Van Baelen, Guy; Vreysen, Steven; Gerbaud, Vincent; Rodriguez-Donis, Ivonne; Geens, Jeroen; Janssens, Bart

    2010-01-01

    Solvent recovery is becoming a major issue in the pharmaceutical and specialty chemical industries. Solvent recovery by conventional batch distillation is limited by the frequent presence of azeotropes in the used solvent mixtures. Most distillation processes for the separation of azeotropic or difficult zeotropic mixtures involve the addition of an entrainer (homogeneous and heterogeneous azeotropic distillation or extractive distillation). In this study the recovery of IPA (isopropyl alc...

  16. Batch extractive distillation with light entrainer

    OpenAIRE

    Varga, Viktoria; Rev, Endre; Gerbaud, Vincent; Lelkes, Zoltan; Fonyo, Zsolt; Joulia, Xavier

    2006-01-01

    Use of a light entrainer in batch extractive distillation is justified when the mixture boils at a high temperature, or when an appropriate heavy or intermediate entrainer cannot be found. Feasibility of batch extractive distillation with light entrainer for separating minimum and maximum boiling azeotropes and close boiling mixtures is studied in this article. Our test mixtures are: ethanol / water (minimum boiling azeotrope) with methanol, water / ethylene diamine (maximum boiling azeotrope...

  17. Systematic screening methodology and energy efficient design of ionic liquid-based separation processes

    DEFF Research Database (Denmark)

    Kulajanpeng, Kusuma; Suriyapraphadilok, Uthaiporn; Gani, Rafiqul

    2016-01-01

    A systematic methodology for the screening of ionic liquids (ILs) as entrainers and for the design of ILs-based separation processes in various homogeneous binary azeotropic mixtures has been developed. The methodology focuses on the homogeneous binary aqueous azeotropic systems (for example, wat...

  18. Study on the Batch Extractive Distillation of Azeotropic MixtureBenzene-Methyl Cyclopentane by Mixed Solvent N-Formylmorpholine-Ethylene Glycol%N-甲酰吗啉-乙二醇混合溶剂间歇萃取精馏苯-甲基环戊烷的研究

    Institute of Scientific and Technical Information of China (English)

    华超; 李鑫钢; 徐世民; 任培兵; 朱占生; 马沛生

    2006-01-01

    利用改进的UNIFAC模型来选择萃取精馏苯-甲基环戊烷过程中的混合萃取剂,对混合溶剂N-甲酰吗啉(NFM)-乙二醇(EG)对萃取精馏苯-甲基环戊烷的过程进行了详细的理论分析和实验研究,重点考察了混合溶剂配比和溶剂比对分离过程可行性的影响.研究结果表明,混合溶剂NFM-EG具有良好的选择性和溶解性,为粗苯精制过程中苯-甲基环戊烷的分离提供了必要的基础数据和指导.

  19. REGSOLexpert: Entrainer Selection Tool for waste solvent recovery by batch distillation processes

    OpenAIRE

    Rodriguez-Donis, Ivonne; Gerbaud, Vincent; Baudouin, Olivier; Joulia, Xavier

    2009-01-01

    A general procedure to systematize the search of several alternatives enabling the separation of non-ideal binary mixtures such as pressure-swing distillation, azeotropic and extractive distillation is presented. The use of heterogeneous entrainers is specially highlighted.

  20. Batch Extractive Distillation with Light Entrainer

    OpenAIRE

    Varga, Viktoria; Rev, Endre; Gerbaud, Vincent; Fonyo, Zsolt; Joulia, Xavier

    2006-01-01

    Use of a light entrainer in batch extractive distillation is justified when the mixture boils at a high temperature, or when an appropriate heavy or intermediate entrainer cannot be found. Feasibility of batch extractive distillation with light entrainer for separating minimum and maximum boiling azeotropes and close boiling mixtures is studied in this article. Our test mixtures are: ethanol/water (minimum boiling azeotrope) with methanol, water/ethylene diamine (maximum boiling azeotro...

  1. From batch to continuous extractive distillation using thermodynamic insight: class 1.0-2 case B

    OpenAIRE

    Shen,Weifeng; Benyounes, Hassiba; Gerbaud, Vincent

    2011-01-01

    A systematic feasibility analysis is presented for the separation azeotropic mixtures by batch and continuous extractive distillation. Based on batch feasibility knowledge, batch and continuous separation feasibility is studied under reflux ratio and entrainer flow-rate for the ternary system chloroform-vinyl acetate-butyl acetate, which belongs to the class 1.0-2 separating maximum boiling temperature azeotropes using a heavy entrainer. How information on feasibility of batch mode could be e...

  2. Heterogeneous batch distillation processes for waste solvent recovery in pharmaceutical industry

    OpenAIRE

    Rodriguez-Donis, Ivonne; Gerbaud, Vincent; Arias-Barreto, Alien; Joulia, Xavier

    2009-01-01

    A summary about our experiences in the introduction of heterogeneous entrainers in azeotropic and extractive batch distillation is presented in this work. Essential advantages of the application of heterogeneous entrainers are showed by rigorous simulation and experimental verification in a bench batch distillation column for separating several azeotropic mixtures such as acetonitrile – water, n hexane – ethyl acetate and chloroform – methanol, commonly found in pharmaceutical industry.

  3. Novel approach to predict the azeotropy at any pressure using classification by subgroups

    Directory of Open Access Journals (Sweden)

    Taehyung Kim

    2012-11-01

    Full Text Available Distillation is one of the dominating separation processes, but there are some problems as inseparable mixtures areformed in some cases. This phenomenon is called as azeotropy. It is essential to understand azeotropy in any distillationprocesses since azeotropes, i.e. inseparable mixtures, cannot be separated by ordinary distillation. In this study, to constructa model which predicts the azeotropic formation at any pressure, a novel approach using support vector machine (SVM ispresented. The SVM method is used to classify data in the two classes, that is, azeotropes and non-azeotropes. 13 variables,including pressure, were used as explanatory variables in this model. From the result of the SVM models which were constructed with data measured at 1 atm and data measured at all pressures, the 1 atm model showed a higher prediction performance to the data measured at 1 atm than the all pressure model. Thus, for improving the performance of the all pressuremodel, we focused on intermolecular forces of solvents. The SVM models were constructed with only data of the solventshaving same subgroups. The accuracy of the model increased and it is expected that this proposed method will be used topredict azeotropic formation at any pressure with high accuracy.

  4. Selection of ionic liquids for the extraction of aromatic hydrocarbons from aromatic/aliphatic mixtures

    NARCIS (Netherlands)

    Meindersma, G. Wytze; Podt, Anita (J.G.); Haan, de André B.

    2005-01-01

    The separation of aromatic hydrocarbons (benzene, toluene, ethyl benzene and xylenes) from C4 to C10 aliphatic hydrocarbon mixtures is challenging since these hydrocarbons have boiling points in a close range and several combinations form azeotropes. In this work, we investigated the separation of t

  5. Development of one-pot three component reaction for the synthesis of N′-aryl-N-cyanoformamidines, essential precursors of formamidine pesticides family

    Directory of Open Access Journals (Sweden)

    Antonio De Nino

    2016-01-01

    Full Text Available Efficient one-pot three component reaction of aniline derivatives with cyanoamide and triethyl orthoformate at reflux in toluene affords N′-aryl-N-cyanoformamidines in high yields just by the distillation of the azeotrope toluene/ethyl alcohol. Labelled d9-Amitraz is prepared by the application of this procedure in the synthesis of formamidine pesticides family.

  6. Effects of drying method on preparation of nanometer α-Al2O3

    Institute of Scientific and Technical Information of China (English)

    XIAO Jin; WAN Ye; DENG Hua; LI Jie; LIU Ye-xiang

    2007-01-01

    Ammonium aluminum carbonate hydroxide (AACH) precursor was synthesized by the precipitation reaction of aluminum sulfate and ammonium carbonate. Then the precursor was dealt with five drying methods including ordinary drying, alcohol exchange, vacuum freeze-drying, glycol distillation, n-butanol azeotropic distillation respectively and calcined at 1 200 ℃ for 2 h to get α-Al2O3. The effects of drying methods on preparation of nanometer α-Al2O3 were discussed, and the optimal drying method was confirmed. The structural properties of powders were characterized by XRD, SEM and BET measurements. The results show that vacuum freeze-drying, glycol distillation and n-butanol azeotropic distillation can prevent the powders from aggregating, and among them the n-butanol azeotropic distillation is the best method. The nanometer α-Al2O3 powder with non-aggregation can be manufactured using n-butanol azeotropic distillation and the average particle size is about 40 nm.

  7. Vapor-Liquid Equilibria Using the Gibbs Energy and the Common Tangent Plane Criterion

    Science.gov (United States)

    Olaya, Maria del Mar; Reyes-Labarta, Juan A.; Serrano, Maria Dolores; Marcilla, Antonio

    2010-01-01

    Phase thermodynamics is often perceived as a difficult subject with which many students never become fully comfortable. The Gibbsian geometrical framework can help students to gain a better understanding of phase equilibria. An exercise to interpret the vapor-liquid equilibrium of a binary azeotropic mixture, using the equilibrium condition based…

  8. Extractive distillation: recent advances in operation strategies

    OpenAIRE

    Shen,Weifeng; Benyounes, Hassiba; Gerbaud, Vincent

    2014-01-01

    International audience; Extractive distillation is one of the efficient techniques for separating azeotropic and low-relativevolatility mixtures in various chemical industries. This paper first provides an overview of thermodynamic insight covering residue curve map analysis, the application of univolatility and unidistribution curves, and thermodynamic feasibility study. The pinch-point analysis method combining bifurcation shortcut presents another branch of study, and several achievements ...

  9. Production of ethanol from refinery waste gases. Phase 2, technology development, annual report

    Energy Technology Data Exchange (ETDEWEB)

    Arora, D.; Basu, R.; Phillips, J.R.; Wikstrom, C.V.; Clausen, E.C.; Gaddy, J.L.

    1995-07-01

    Oil refineries discharge large volumes of H{sub 2}, CO, and CO{sub 2} from cracking, coking, and hydrotreating operations. This program seeks to develop a biological process for converting these waste gases into ethanol, which can be blended with gasoline to reduce emissions. Production of ethanol from all 194 US refineries would save 450 billion BTU annually, would reduce crude oil imports by 110 million barrels/year and emissions by 19 million tons/year. Phase II efforts has yielded at least 3 cultures (Clostridium ljungdahlii, Isolate O-52, Isolate C-01) which are able to produce commercially viable concentrations of ethanol from CO, CO{sub 2}, and H{sub 2} in petroleum waste gas. Single continuous stirred tank reactor studies have shown that 15-20 g/L of ethanol can be produced, with less than 5 g/L acetic acid byproduct. Culture and reactor optimization in Phase III should yield even higher ethanol concentrations and minimal acetic acid. Product recovery studies showed that ethanol is best recovered in a multi-step process involving solvent extraction/distillation to azeotrope/azeotropic distillation or pervaporation, or direct distillation to the azeotrope/azeotropic distillation or pervaporation. Projections show that the ethanol facility for a typical refinery would require an investment of about $30 million, which would be returned in less than 2 years.

  10. Substitution of carcinogenic solvent dichloromethane for the extraction of volatile compounds in a fat-free model food system.

    Science.gov (United States)

    Cayot, Nathalie; Lafarge, Céline; Bou-Maroun, Elias; Cayot, Philippe

    2016-07-22

    Dichloromethane is known as a very efficient solvent, but, as other halogenated solvents, is recognized as a hazardous product (CMR substance). The objective of the present work is to propose substitution solvent for the extraction of volatile compounds. The most important physico-chemical parameters in the choice of an appropriate extraction solvent of volatile compounds are reviewed. Various solvents are selected on this basis and on their hazard characteristics. The selected solvents, safer than dichloromethane, are compared using the extraction efficiency of volatile compounds from a model food product able to interact with volatile compounds. Volatile compounds with different hydrophobicity are used. High extraction yields were positively correlated with high boiling points and high Log Kow values of volatile compounds. Mixtures of solvents such as azeotrope propan-2-one/cyclopentane, azeotrope ethyl acetate/ethanol, and mixture ethyl acetate/ethanol (3:1, v/v) gave higher extraction yields than those obtained with dichloromethane.

  11. Experimental determination of the isothermal (vapour + liquid) equilibria of binary aqueous solutions of sec-butylamine and cyclohexylamine at several temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Chiali-Baba Ahmed, Nouria [LATA2M, Laboratoire de Thermodynamique Appliquee et Modelisation Moleculaire, University AbouBekr Belkaid of Tlemcen, Post Office Box 119, Tlemcen 13000 (Algeria); Negadi, Latifa, E-mail: latifanegadi@yahoo.fr [LATA2M, Laboratoire de Thermodynamique Appliquee et Modelisation Moleculaire, University AbouBekr Belkaid of Tlemcen, Post Office Box 119, Tlemcen 13000 (Algeria); Mokbel, Ilham [LSA, Laboratoire des Sciences Analytiques, CNRS-UMR 5280, Universite Claude Bernard - Lyon I, 43, Bd du 11 Novembre 1918, Villeurbanne Cedex 69622 (France); Kaci, Ahmed Ait [Laboratoire de Thermodynamique et Modelisation Moleculaire, Universite des Sciences et de la Technologie Houari Boumediene, Post Office Box 32, El Alia 16111, Bab Ezzouar (Algeria); Jose, Jacques [LSA, Laboratoire des Sciences Analytiques, CNRS-UMR 5280, Universite Claude Bernard - Lyon I, 43, Bd du 11 Novembre 1918, Villeurbanne Cedex 69622 (France)

    2012-01-15

    Highlights: > Vapour pressures of sec-butylamine or cyclohexylamine and their aqueous solutions. > The investigated temperatures are 273 K and 363 K. > The (cyclohexylamine + water) mixture shows positive azeotropic behaviour. > The (sec-butylamine + water) or (cyclohexylamine + water) exhibit positive G{sup E}. - Abstract: The vapour pressures of (sec-butylamine + water), (cyclohexylamine + water) binary mixtures, and of pure sec-butylamine and cyclohexylamine components were measured by means of two static devices at temperatures between 293 (or 273) K and 363 K. The data were correlated with the Antoine equation. From these data, excess Gibbs functions (G{sup E}) were calculated for several constant temperatures and fitted to a fourth-order Redlich-Kister equation using the Barker's method. The (cyclohexylamine + water) system shows positive azeotropic behaviour for all investigated temperatures. The two binary mixtures exhibit positive deviations in G{sup E} for all investigated temperatures over the whole composition range.

  12. Vapor-liquid equilibria for the binary systems of 1-butanol with some halohydrocarbons at 40.0 and 101.3 kPa

    Energy Technology Data Exchange (ETDEWEB)

    Artigas, H.; Lafuente, C.; Cea, P.; Royo, F.M.; Urieta, J.S. [Univ. de Zaragoza (Spain)

    1997-01-01

    Isobaric vapor-liquid equilibrium measurements at 40.0 and 101.3 kPa are reported for 1-butanol + chlorocyclohexane, + chlorobenzene, + bromocyclohexane, + bromobenzene. Some of the studied systems show minimum temperature azeotropes. The experimental data were tested for thermodynamic consistency and satisfactorily correlated with the Margules, Van Laar, Wilson, NRTL, and UNIQUAC equations. Predictions with the UNIFAC method and ASOG method were also obtained.

  13. A New Approach to Dyeing of 80 : 20 Polyester/Cotton Blended Fabric Using Disperse and Reactive Dyes

    OpenAIRE

    2011-01-01

    Polyester/Cotton blended fabrics are normally dyed by two-bath or one-bath two-step dyeing method. This paper deals with a new approach involving azeotropic ternary mixture of organic solvents pretreatment to dye polyester/cotton blends using disperse and reactive dyes in one-bath method. The effect of solvent pretreatments on dyeability, fastness, and few physicochemical properties has been investigated involving SEM, FTIR, DSC, and XRD studies, and results are presented.

  14. Cleaning and materials compatibility test results for elimination of flammable solvents in wipe applications.

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Edwin Paul

    2005-06-01

    In recent years, efforts have been made within the nuclear weapons complex (National Nuclear Security Administration) of the Department of Energy (DOE) to replace Resource Conservation and Recovery Act (RCRA) regulated solvents (i.e., flammable, toxic, corrosive, and reactive) and ozone-depleting chemicals (ODC) with more benign alternatives. Within the National Nuclear Security Administration (NNSA) and the Department of Defense (DoD) sectors, these solvents are used for cleaning hardware during routine maintenance operations. A primary goal of this study is to replace flammable solvents used in wiping applications. Two cleaners, including a hydrofluoroether (HFE) and an azeotrope of the HFE and isopropyl alcohol (IPA), have been studied as potential replacements for flammable solvents. Cleaning efficacy, short-term and long-term materials compatibility, corrosion, drying times, flammability, environment, safety and health (ES&H) and accelerated aging issues were among the experiments used to screen candidate solvents by the interagency team performing this work. This report presents cleaning efficacy results as determined by the contact angle Goniometer as well as materials compatibility results of various metal alloys and polymers. The results indicate that IPA (baseline cleaner) and the HFE/IPA azeotrope are roughly equivalent in their ability to remove fluorinated grease, silicone grease, and a simulated finger print contaminant from various metal alloys. All of the ASTM sandwich and immersion corrosion tests with IPA, HFE or the HFE/IPA azeotrope on metal alloys showed no signs of corrosion. Furthermore, no deleterious effects were noted for polymeric materials immersed in IPA, HFE, or the HFE/IPA azeotrope.

  15. Isobaric vapor-liquid equilibria in the systems methyl 1,1-dimethylethyl ether + hexane and + heptane

    Energy Technology Data Exchange (ETDEWEB)

    Wisniak, J.; Magen, E.; Shachar, M.; Zeroni, I.; Segura, H. [Ben-Gurion Univ. of the Negev, Beer-Sheva (Israel). Dept. of Chemical Engineering; Reich, R. [Univ. de Concepcion (Chile). Dept. of Chemical Engineering

    1997-03-01

    The vapor-liquid equilibrium at 94 kPa has been determined for the binary systems of methyl 1,1-dimethylethyl ether (MTBE) with hexane and with heptane. Both systems deviate slightly from ideal behavior, can be described as regular solutions, and do not present an azeotrope. The activity coefficients and boiling point of the solutions were correlated with its composition by the Redlich-Kister, Wohl, Wilson, UNIQUAC, NRTL, and Wisniak-Tamir equations.

  16. Separation of ethanol-water mixtures using 3A molecular sieve

    Energy Technology Data Exchange (ETDEWEB)

    Carton, A.; Gonzalez, G.; Iniguez de la Torre, A.; Cabezas, J.L.

    1987-01-01

    An experimental study of 3A molecular sieve behavior, in order to obtain anhydrous ethanol, was developed. The adsorption of water in vapor phase was performed in an essentially isothermal fixed bed. 99.9 wt% ethanol was recovered operating with azeotropic distillation and different flow rates. A simple model in terms of a driving force and linear equilibrium was tested. Runs in liquid phase were also carried out, obtaining lower treatment-capacities than when working in vapor phase.

  17. HIDiC - Design, Sensitivity and Graphical Representation

    DEFF Research Database (Denmark)

    Meyer, K.; Ianniciello, L.; Nielsen, J. E.;

    2014-01-01

    We have explored the applicability of recent design methods based on H-xy diagrams for the HIDiC [i,ii] also for non-ideal and azeotropic systems. When applied together with sensitivity analysis and verification through rigorous simulations based on a newly developed and detailed HIDiC model......, these concepts widen the scope of HIDiC design of a larger range of industrially relevant separations....

  18. Recent Membrane Development for Pervaporation Processes

    KAUST Repository

    Ong, Yee Kang

    2016-03-11

    Pervaporation has been regarded as a promising separation technology in separating azeotropic mixtures, solutions with similar boiling points, thermally sensitive compounds, organic–organic mixtures as well as in removing dilute organics from aqueous solutions. As the pervaporation membrane is one of the crucial factors in determining the overall efficiency of the separation process, this article reviews the research and development (R&D) of polymeric pervaporation membranes from the perspective of membrane fabrication procedures and materials.

  19. The Environmental Assessment and Management (TEAM) Guide; Rhode Island Supplement, Revised March 1998

    Science.gov (United States)

    1998-03-01

    drying by tumbling in an airstream. The facility includes, but is not limited to, any washer, dryer , filter, and purification system; waste disposal...solvent added to any degreaser or dryer at a facility during the previous calendar year (CRIR 12 031 022(22.1.8)). Anthracite - a hard, black lustrous...Azeotropic Device - an air pollution control device wherein the dryer exhaust from a dry cleaning machine is routed to a tank where the perchloroethylene

  20. Separation of polar compounds using a flexible metal-organic framework

    Energy Technology Data Exchange (ETDEWEB)

    Motkuri, Radha K.; Thallapally, Praveen K.; Annapureddy, Harsha V.; Dang, Liem X.; Krishna, Rajamani; Nune, Satish K.; Fernandez, Carlos A.; Liu, Jian; McGrail, B. Peter

    2015-01-01

    A flexible metal-organic framework constructed from a flexible linker is shown to possess the capability of separating mixtures of polar compounds by exploiting the differences in the saturation capacities of the constituents. The separation possibilities with the flexible MOF include mixtures of propanol isomers, and various azeotropes. Transient breakthrough simulations show that these sorption-based separations are in favor of the component with higher saturation capacity.

  1. Novel method using Dubinin-Astakhov theory in sorption reactor design for refrigeration and heat pump applications

    OpenAIRE

    Tamainot-Telto, Zacharie

    2016-01-01

    This paper presents new methodology that is based on a single given adsorbent-refrigerant pair characteristic (such as activated carbon 208C) leading to the characterization of the same adsorbent (activated carbon 208C) with various refrigerants such as Water, Methanol, Ethanol, R723 (azeotropic mixture of 60% Ammonia and 40% Dimethyl Ether), Dimethyl Ether (DME) and Carbon Dioxide (R744). Overall, the results obtained with both Methanol and Carbon Dioxide (R744) show that the new method pred...

  2. A safer and flexible method for the oxygen functionalization of carbon nanotubes by nitric acid vapors

    Energy Technology Data Exchange (ETDEWEB)

    Santangelo, Saveria, E-mail: saveria.santangelo@unirc.it [Dipartimento di Ingegneria Civile, dell’Energia, dell’Ambiente e dei Materiali (DICEAM), Università “Mediterranea”, 89122 Reggio Calabria (Italy); Piperopoulos, Elpida [Dipartimento di Ingegneria Eletronica, Chimica ed Ingegneria Industriale (DIECII), Università di Messina, 98166 Messina (Italy); Fazio, Enza [Dipartimento di Fisica e di Scienze della Terra (DFST), Università di Messina, 98166 Messina (Italy); Faggio, Giuliana [Dipartimento di Ingegneria dell’Informazione, delle Infrastrutture e dell’Energia Sostenibile (DIIES), Università “Mediterranea”, 89122 Reggio Calabria (Italy); Ansari, Shabana [Dipartimento di Ingegneria Eletronica, Chimica ed Ingegneria Industriale (DIECII), Università di Messina, 98166 Messina (Italy); Lanza, Maurizio [Istituto per i Processi Chimico Fisici (IPCF) del CNR, 98158 Messina (Italy); Neri, Fortunato [Dipartimento di Fisica e di Scienze della Terra (DFST), Università di Messina, 98166 Messina (Italy); Messina, Giacomo [Dipartimento di Ingegneria dell’Informazione, delle Infrastrutture e dell’Energia Sostenibile (DIIES), Università “Mediterranea”, 89122 Reggio Calabria (Italy); Milone, Candida [Dipartimento di Ingegneria Eletronica, Chimica ed Ingegneria Industriale (DIECII), Università di Messina, 98166 Messina (Italy)

    2014-06-01

    The functionalization by nitric acid vapors at azeotropic concentration has been recently proposed to eliminate drawbacks of the widely utilized liquid phase functionalization method. This work suggests to exploit the so-called “salt effect” to improve the vapor phase oxidation method in terms of safety and flexibility. Increasing the relative volatility of acid, the addition of Mg(NO{sub 3}){sub 2} salt to the HNO{sub 3} + H{sub 2}O solution allows (i) obtaining vapors with HNO{sub 3} at the azeotropic concentration from a more diluted liquid solution (i.e. operating under safer conditions), and (ii) varying the concentration of HNO{sub 3} in the vapor phase even above the azeotropic concentration limit (with improved process flexibility). High-resolution transmission electron microscopy, thermo-gravimetry, Raman spectroscopy and X-ray photoemission spectroscopy systematic analyses are carried out on pristine and oxidized nanotubes in order to assess their functionalization degree, surface chemistry and structural evolution. The most relevant finding of this preliminary study is that the nanotube functionalization extent increases linearly with the HNO{sub 3} vapor concentration.

  3. Mathematical modeling of a single stage ultrasonically assisted distillation process.

    Science.gov (United States)

    Mahdi, Taha; Ahmad, Arshad; Ripin, Adnan; Abdullah, Tuan Amran Tuan; Nasef, Mohamed M; Ali, Mohamad W

    2015-05-01

    The ability of sonication phenomena in facilitating separation of azeotropic mixtures presents a promising approach for the development of more intensified and efficient distillation systems than conventional ones. To expedite the much-needed development, a mathematical model of the system based on conservation principles, vapor-liquid equilibrium and sonochemistry was developed in this study. The model that was founded on a single stage vapor-liquid equilibrium system and enhanced with ultrasonic waves was coded using MATLAB simulator and validated with experimental data for ethanol-ethyl acetate mixture. The effects of both ultrasonic frequency and intensity on the relative volatility and azeotropic point were examined, and the optimal conditions were obtained using genetic algorithm. The experimental data validated the model with a reasonable accuracy. The results of this study revealed that the azeotropic point of the mixture can be totally eliminated with the right combination of sonication parameters and this can be utilized in facilitating design efforts towards establishing a workable ultrasonically intensified distillation system.

  4. 甲醇-丙酮体系的间歇萃取精馏研究%Study on batch extractive distillation for methanol-acetone system

    Institute of Scientific and Technical Information of China (English)

    王益辉; 袁旭宏; 黄海明; 陈红; 叶余原; 尤玉静; 熊双喜

    2014-01-01

    The methanol-acetone azeotrope was separated by batch extractive distillation with distilled water as extracting agent. The effect of factors of extractant, total reflux time, azeotrope composition, volume ratio of sol-vent and compound, saline and alkaline on batch extractive distillation azeotrope system was investigated. The best extraction conditions were obtained.%在常规的间歇萃取精馏实验装置中,研究了以蒸馏水为萃取剂间歇萃取精馏分离甲醇-丙酮共沸物的过程。考察了萃取剂、全回流时间、共沸物组成、溶剂与混合物的体积比、加盐、加碱等因素对萃取精馏分离甲醇-丙酮共沸体系的影响,从而得出最佳的萃取条件。

  5. 单乙醇胺(MEA)间歇萃取精馏甲醇-丙酮研究%Study on Batch Extractive Distillation of Methanol and Acetone by Using MEA as Extractant

    Institute of Scientific and Technical Information of China (English)

    曾春元; 袁旭宏; 黄海明; 陈红; 叶余原; 尤玉静; 熊双喜

    2014-01-01

    s:Batch extractive distillation process of methanol-acetone binary azeotrope in the conventional batch extractive distillation experimental device with MEA as extracting agent was studied. Effect of extractant, total reflux time, azeotrope composition,volume ratio of solvent and mixture,reflux ratio and other factors on the extractive distillation separation of methanol - acetone azeotropic system was investigated, and the best extraction conditions were determined.%用常规的间歇萃取精馏实验装置,研究了以单乙醇胺(MEA)为萃取剂间歇萃取精馏分离甲醇—丙酮恒沸物的过程。考察了萃取剂、全回流时间、共沸物组成、溶剂与混合物的体积比、回流比等因素对萃取精馏分离甲醇—丙酮共沸体系的影响,从而得出最优的萃取条件。

  6. The Separation of Catechol from Carbofuran Phenol by Extractive Distillation%萃取精馏分离呋喃酚中邻苯二酚

    Institute of Scientific and Technical Information of China (English)

    张建宇; 胡艾希; 王宇; 肖旭辉; 郭家斌; 罗先福

    2009-01-01

    In this study, extractive distillation has been applied to separate catechol (CAT) from carbofuran phenol (CFP) with high purity and yield. The relative volatility of CFP to CAT was measured, and the choice of separating agents was investigated. The experimental results indicated that CFP/CAT is an azeotropic system with an azeotropic point at 93.40℃/0.400 kPa and an azeotropic mixture containing 49.96% of CFP and 50.04% of CAT. Data from the determination of the relative volatility have shown that separating agents such as diglycol and 4-butylcatechol (4-TBC) are able to increase the relative volatility up to 1.90. In one shot process batch extractive distillation of CFP mixture with 3% (by mass) diglycol as separating agent, the purity and yield of the obtained CFP was 99.0% and 95.0%, respectively, while the distillation without separating agent provided a purity and yield of only 98.0% and 90.0%, respectively. There was no residual separating agent found in the product.

  7. Liquid-vapor phase relations in the Si-O system: A calorically constrained van der Waals-type model

    Science.gov (United States)

    Connolly, James A. D.

    2016-09-01

    This work explores the use of several van der Waals (vW)-type equations of state (EoS) for predicting vaporous phase relations and speciation in the Si-O system, with emphasis on the azeotropic boiling curve of SiO2-rich liquid. Comparison with the observed Rb and Hg boiling curves demonstrates that prediction accuracy is improved if the a-parameter of the EoS, which characterizes vW forces, is constrained by ambient pressure heat capacities. All EoS considered accurately reproduce metal boiling curve trajectories, but absent knowledge of the true critical compressibility factor, critical temperatures remain uncertain by ~500 K. The EoS plausibly represent the termination of the azeotropic boiling curve of silica-rich liquid by a critical point across which the dominant Si oxidation state changes abruptly from the tetravalent state characteristic of the liquid to the divalent state characteristic of the vapor. The azeotropic composition diverges from silica toward metal-rich compositions with increasing temperature. Consequently, silica boiling is divariant and atmospheric loss after a giant impact would enrich residual silicate liquids in reduced silicon. Two major sources of uncertainty in the boiling curve prediction are the heat capacity of silica liquid, which may decay during depolymerization from the near-Dulong-Petit limit heat capacity of the ionic liquid to value characteristic of the molecular liquid, and the unknown liquid affinity of silicon monoxide. Extremal scenarios for these uncertainties yield critical temperatures and compositions of 5200-6200 K and Si1.1O2-Si1.4O2. The lowest critical temperatures are marginally consistent with shock experiments and are therefore considered more probable.

  8. SIMULATION AND ANALYSIS OF DOUBLE COLUMN RECOVERY PROCESS IN LUBE FURFURAL REFINING%润滑油糠醛精制双塔回收过程的模拟与分析

    Institute of Scientific and Technical Information of China (English)

    韩威; 王迎军

    2001-01-01

    A model for double column recovery process in lube furfural refining was established, which was based on the principle of the hetrogeneous azeotrope with low azeotropic point in the furfural-water system. The activity coefficient was calculated by UNIFAC equation. The operating features of the furfural drying column and the aqueous solution stripper were discussed by utilizing the calculation result from the model. The dry furfural can be obtained and the composition of the tops was close to the composition of furfural-water azeotrope. It was proposed to minimize the stripping steam of the aqueous solution stripper at the premise of a qualified drainage.%根据糠醛装置双塔回收工艺利用糠醛-水系统非均相低共沸性质的过程原理,建立了润滑油糠醛精制双塔回收模型,模型中采用 UNIFAC 方程计算活度系数;利用模型计算的结果讨论了糠醛干燥塔和水溶液汽提塔的操作特性。通过对糠醛干燥塔中热醛汽流量的控制,可获得干燥糠醛,并使塔顶馏出物的组成接近糠醛-水共沸组成;在保证废水含醛达到排放标准的情况下,水溶液汽提塔中吹入的汽提蒸汽量应尽量少。

  9. Densities and vapor-liquid equilibria in binary mixtures formed by propyl methanoate + ethanol, + propan-1-ol, and + butan-1-ol at 160.0 kPa

    Energy Technology Data Exchange (ETDEWEB)

    Falcon, J.; Ortega, J.; Gonzalez, E. [Escuela Superior de Ingenieros Industriales, Las Palmas (Spain). Laboratorio de Termodinamica y Fisicoquimica

    1996-07-01

    Densities and excess volumes were determined at 298.15 K for propyl methanoate + ethanol, + propan-1-ol, and + butan-1-ol. The results of those quantities were then correlated to get the concentrations of vapor-liquid equilibrium obtained isobarically at 160 kPa for the same mixtures. Two mixtures show azeotropes: for propyl methanoate (1) + ethanol (2), x{sub 1} = 0.443 at T = 358.7 K; and for propyl methanoate (1) + propan-1-ol (2), x{sub 1} = 0.762 at T = 368.2 K. The mixtures are thermodynamically consistent, and the predictions made using several group-contribution models are satisfactory.

  10. Washery tailings from coal preparation used as aluminium feedstock

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, L.; Schieder, T.; Belsky, M.; Lotze, J.; Winkhaus, G.

    1982-06-01

    Kaolinite clays and washery tailings of coal mines are the major feedstocks of the West German aluminium industry. Statistics are given in order to assess the amount of washery tailings available and their suitability as feedstocks for aluminium production. The chemical and mineralogical composition are similar for washery tailings from different mines; accordingly, also their behaviour regarding decomposition by acids will be almost identical. Al/sub 2/O/sub 3/ extraction yields are satisfactory with strongly precalcinated material using concentrated sulphuric acid or azeotropic hydrochloric acid - in the latter case, however, only if fluoride is added to the acid.

  11. Isobaric vapor-liquid equilibria in the system methyl propanoate + n-butyl alcohol

    Energy Technology Data Exchange (ETDEWEB)

    Susial, P.; Ortega, J. (Univ. de Las Palmas de Gran Canaria, Canary Islands (Spain). Lab. de Termodinamica y Fisicoquimica)

    1993-10-01

    Isobaric vapor-liquid equilibria were determined at 74.66, 101.32, and 127.99 kPa for binary mixtures containing methyl propanoate + n-butyl alcohol by using a dynamic still with vapor and liquid circulation. No azeotrope was detected. The data were found to be thermodynamically consistent according to the point to point test. Application of the group-contribution models ASOG, UNIFAC, and modified UNIFAC to the activity coefficients at the three pressures studied gives average errors of less than 10%, 11%, and 3%, respectively.

  12. Vapor-Liquid Equilibrium of Ethyl Acetate+C_nH_(2n+1)OH(n=1,2,3) Binary Systems at 0.3 MPa

    Institute of Scientific and Technical Information of China (English)

    SUSIAL P.; RODRIGUEZ-HENRIQUEZ J.J.; SOSA-ROSARIO A.; RIOS-SANTANA R.

    2012-01-01

    Vapor-liquid equilibrium data for the binary systems of ethyl acetate + methanol,ethyl acetate + ethanol and ethyl acetate + 1-propanol at 0.3 MPa were determined.The experimental data were verified with the point-to-point test of van Ness(1973).All these systems present an azeotropic point at 0.3 MPa that increases in ester composition for longer alcohol chains.The UNIFAC in different versions and ASOG prediction models were applied.

  13. Low-Temperature Miscibility of Ethanol-Gasoline-Water Blends in Flex Fuel Applications

    DEFF Research Database (Denmark)

    Johansen, T.; Schramm, Jesper

    2009-01-01

    The miscibility of blends of gasoline and hydrous ethanol was investigated experimentally at - 25 degrees C and - 2 degrees C. Furthermore, the maximum water content was found for ethanol in flex fuel blends. The results strongly indicate that blends containing ethanol with a water content above...... that of the ethanol/water azeotrope (4.4% water by mass) can be used as Flex Fuel blends together with gasoline at ambient temperatures of 25 degrees C and 2 degrees C, without phase separation occurring. Additionally, it was shown that the ethanol purity requirement of ethanol-rich flex fuel blends falls...... with increasing ethanol content in the gasoline-rich flex fuel blend....

  14. Capillary origami and superhydrophobic membrane surfaces

    Science.gov (United States)

    Geraldi, N. R.; Ouali, F. F.; Morris, R. H.; McHale, G.; Newton, M. I.

    2013-05-01

    Capillary origami uses surface tension to fold and shape solid films and membranes into three-dimensional structures. It uses the fact that solid surfaces, no matter how hydrophobic, will tend to adhere to and wrap around the surface of a liquid. In this work, we report that a superhydrophobic coating can be created, which can completely suppress wrapping as a contacting water droplet evaporates. We also show that using a wetting azeotropic solution of allyl alcohol, which penetrates the surface features, can enhance liquid adhesion and create more powerful Capillary Origami. These findings create the possibility of selectively shaping membrane substrates.

  15. Consistent thermodynamic properties of lipids systems

    DEFF Research Database (Denmark)

    Cunico, Larissa; Ceriani, Roberta; Sarup, Bent;

    Physical and thermodynamic properties of pure components and their mixtures are the basic requirement for process design, simulation, and optimization. In the case of lipids, our previous works[1-3] have indicated a lack of experimental data for pure components and also for their mixtures...... different pressures, with azeotrope behavior observed. Available thermodynamic consistency tests for TPx data were applied before performing parameter regressions for Wilson, NRTL, UNIQUAC and original UNIFAC models. The relevance of enlarging experimental databank of lipids systems data in order to improve...

  16. Vapor-liquid equilibrium measurements for methyl propanoate-ethanol and methyl propanoate-propan-1-ol at 101. 32 kPa

    Energy Technology Data Exchange (ETDEWEB)

    Susial, P.; Ortega, J. (Catedra de Termodinamica y Fisicoquimica, Escuela Superior de Ingenieros Industriales, Polytechnic University of Canarias, 35017 Las Palmas, Canary Islands (ES)); DeAlfonso, C.; Alonso, C. (Unidad de Tribologia e Ingenieria Quimica, Instituto Rocasolano, CSIC, Madrid (ES))

    1989-04-01

    Isobaric vapor-liquid equilibrium measurements on binary systems of methyl propanoate with ethanol and propan-1-ol are taken at a constant pressure of 101.32 +- 0.02 kPa. These systems exhibit significant deviations from ideality and are shown to be thermodynamically consistent. The methyl propanoate-ethanol system forms an azeotrope at x = y = 0.483 and T = 345.58{Kappa}. Experimental data are fitted to a suitable equation and are likewise compared with the values predicted by the UNIFAC and ASOG models.

  17. Vapor-liquid equilibrium measurements at 101. 32 kPa for binary mixtures of methyl acetate + ethanol or 1-propanol

    Energy Technology Data Exchange (ETDEWEB)

    Ortega, J.: Susial, P.; de Alfonso, C. (Catedra de Termodinamica y Fisicoquimica, Escuela Superior de Ingeieros Industriales, 35071 Univ. of Las Palmas (ES))

    1990-07-01

    This paper reports on isobaric vapor-liquid equilibrium data at 101.32 {plus minus} 0.02 kPa for methyl acetate (1) + ethane (2) or + 1-propanol (2). The results are compared with those predicted by the UNIFAC and ASOG methods. The methyl acetate (1) + ethanol (2) system forms an azeotrope at 329.8 K and a molar concentration of x{sub 1} = 0.958. Both methods predict the vapor-phase compositions equally well, with overall mean errors of less than 5%.

  18. SYNTHESES AND STRUCTURES OF POLYPHENYLSILSESQUIOXANES

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xinsheng; SHI Lianghe

    1987-01-01

    Phenyltrichlorosilane was hydrolyzed both in toluene and in ether from which two kinds of prepolymers were obtained with different structures, molecular weights, and molecular weight distributions.Polymers were prepared from the prepolymers in various polymerization conditions. The ladderlike,branched, and crosslinked structures formed under different polymerization conditions were characterized by means of FTIR, 1H and 29Si-NMR, and elemental analysis. Azeotropic distillation of solvents and H2O formed during polymerization was found useful in removing H2O from the system and high molecular weight products with perfect ladderlike structure were obtained.

  19. Simulation and Analysis on Multiple Steady States of an Industrial Acetic Acid Dehydration System

    Institute of Scientific and Technical Information of China (English)

    李绍军; 黄定伟

    2011-01-01

    In this work, an industrial acetic acid dehydration system via heterogeneous azeotropic distillation is simulated by Aspen Plus software. Residue curves are used to analyze the distillating behavior, and appropriate operating region of the system is determined. Based on steady states simulation, a sensitivity analysis is carried out to detect the output multiple steady states in the system. Different solution branches are observered when the flow rates of the feed stream and the organic reflux stream are selected as manipulated variables. The performance of the column under different steady states is different. A method is oroposed to achieve the desired steady state.

  20. Additives in crude oil. A new attempt to prevent boilover; Additive im Rohoel. Ein neuer Ansatz zur Vermeidung eines Boilover

    Energy Technology Data Exchange (ETDEWEB)

    Gosewinkel, Martin; Dworschak, Rene [INBUREX Consulting GmbH, Hamm (Germany)

    2011-03-15

    Boilover of tanks is a rare cause of serious fires in crude oil storage. The greatest danger is the spill of burning material from the tank. In the research project presented here, a method to prevent boilover and/or reduce its effects was to be developed. One approach is the addition of additives that modify the hetero-azeotropic boiling characteristics of crude oil components in case of fire. Even minimum concentrations of the additive will delay the time until boilover and also reduce its intensity.

  1. (Vapour + liquid) equilibria of the {l_brace}1,1-difluoroethane (HFC-152a) + n-butane (HC-600){r_brace} system

    Energy Technology Data Exchange (ETDEWEB)

    Im, Jihoon [School of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, Shinlim-dong, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Lee, Gangwon [School of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, Shinlim-dong, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Lee, Yong-Jin [School of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, Shinlim-dong, Gwanak-gu, Seoul 151-744 (Korea, Republic of); Kim, Hwayong [School of Chemical and Biological Engineering and Institute of Chemical Processes, Seoul National University, Shinlim-dong, Gwanak-gu, Seoul 151-744 (Korea, Republic of) ]. E-mail: hwayongk@snu.ac.kr

    2007-08-15

    Binary (vapour + liquid) equilibrium data were obtained for the {l_brace}1,1-difluoroethane (HFC-152a) + n-butane (HC-600){r_brace} system at temperatures from 313.15 K to 363.15 K. These experiments were carried out with a circulating-type apparatus with on-line gas chromatography. The experimental data were correlated well by Peng-Robinson equation of state using the Wong-Sandler mixing rules. This system shows positive azeotropic phase behaviour.

  2. Features of non-congruent phase transition in modified Coulomb model of the binary ionic mixture

    Science.gov (United States)

    Stroev, N. E.; Iosilevskiy, I. L.

    2016-11-01

    Non-congruent gas-liquid phase transition (NCPT) have been studied previously in modified Coulomb model of a binary ionic mixture C(+6) + O(+8) on a uniformly compressible ideal electronic background /BIM(∼)/. The features of NCPT in improved version of the BIM(∼) model for the same mixture on background of non-ideal electronic Fermi-gas and comparison it with the previous calculations are the subject of present study. Analytical fits for Coulomb corrections to equation of state of electronic and ionic subsystems were used in present calculations within the Gibbs-Guggenheim conditions of non-congruent phase equilibrium. Parameters of critical point-line were calculated on the entire range of proportions of mixed ions 0 BIM(∼) model. Just similar distillation was obtained in the variant of NCPT in dense nuslear matter. The absence of azeotropic compositions was revealed in studied variants of BIM(∼) in contrast to an explicit existence of the azeotropic compositions for the NCPT in chemically reacting plasmas and in astrophysical applications.

  3. Performance of a new refrigeration cycle using refrigerant mixture R32/R134a for residential air-conditioner applications

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jianyong; Yu, Jianlin [Department of Refrigeration and Cryogenic Engineering, School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China)

    2008-07-01

    In this paper, a new refrigeration cycle (NRC) using the binary non-azeotropic refrigerant mixture R32/R134a is presented, which can be an alternative refrigeration cycle applied in residential air-conditioner. In the NRC, refrigerant circuit of the evaporator is separated into two branches. Because the non-azeotropic mixture has the characteristic of temperature glide, an important benefit of such configuration is that the Lorentz cycle can be realized. Compared with that of conventional cycle configuration, the new cycle efficiency can be improved. The calculating results show that, in the conventional refrigeration cycle (CRC), the mixture R32/R134a has a close performance to that is obtainable with pure refrigerant R22. However, the mixture R32/R134a in the NRC will result in a better performance. The maximal COP can be improved in a range of 8-9% over that of the CRC, and the volumetric refrigerating capacity can be approximately increased by 9.5%. (author)

  4. Elemental composition method for computation and analysis of simultaneous chemical and phase equilibrium

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    An elemental composition method for computation and analysis of simultaneous chemical and phase equilibrium (CPE) of non-ideal mixtures is proposed. The concept of element is defined, the relationship between component composition and elemental composition is derived, and the concept of elemental potential and its physical meaning are further cleared from the view point of thermodynamics. The relationship between chemical potential and elemental potential is derived in the thermodynamic principles, and the computation equations for CPE problem are obtained based on elemental potential. A simple form of necessary and sufficient condition in terms of elemental composition for reactive azeotropes is derived, which takes the same functional form as the condition for azeotropes in non-reactive systems. The element in this note may be atoms, molecules or group radicals. The presented method is applicable to CPE problem of non-ideal mixtures, and the computation can be simplified by the dimension reducing method. The presented method was supplied to compute and analyze CPE problem of several examples and it is found that it is a robust and efficient method.

  5. Conceptual analysis of single-feed heterogeneous distillation columns

    Directory of Open Access Journals (Sweden)

    Carlos Arturo Martinez Riascos

    2015-08-01

    Full Text Available Separation in heterogeneous distillation columns is attained by interaction of two liquid and one vapor phases, interaction of three phases involves complexities due to the determination of vapor-liquid-liquid equilibrium and hence, in the design of separation units. Nevertheless, the liquid-liquid equilibrium allows developing separations that may be unfeasible by vapor-liquid equilibrium. In this way, heterogeneous azeotropic distillation is a useful operation for the separation of azeotropic and close-boiling mixtures. In this work, a new methodology for evaluating the feasibility of this process is developed. This methodology is an extension of that proposed by Castillo et al. (1998 for homogeneous systems. Operation leaves for heterogeneous systems are calculated using the concept of pinch point curves in order to establish the process feasibility. Heterogeneous columns with external decanter are considered as the only heterogeneous stage (OHED: only heterogeneous external decanter. The initialization process for the column calculation requires the selection of the distillate composition using thermodynamic criteria in order to guarantee homogeneous phases within the column. A system with industrial and academic relevance was considered as case study: water-acetic acid-amyl acetate. Results show that the developed shortcut method allows evaluating process feasibility and estimating design parameters, without the use of trial and error procedures implemented, with the aid of simulation tools. 

  6. ETHANOL DEHYDRATION IN PACKED DISTILLATION COLUMN USING GLYCEROL AS ENTRAINER: EXPERIMENTS AND HETP EVALUATION

    Directory of Open Access Journals (Sweden)

    W. L. R. Souza

    Full Text Available Abstract The ethanol-water separation is very important because ethanol is widely applied in the chemical industry and its use as a fuel can reduce the pollution emitted to the air. However, anhydrous ethanol production using conventional distillation is impossible, at atmospheric pressure, due to the presence of an azeotrope. In the present work, experimental tests were carried out in order to evaluate the use of glycerol as an entrainer, in substitution of ethylene glycol in an extractive distillation. The use of glycerol is motivated by the biodiesel production units, due to the fact that it is the main byproduct and a new market is necessary to consume its overproduction. The experiments were carried out in a distillation column packed with Raschig rings, varying the glycerol/feed (ethanol and water ratio, S/F, from 0.5 to 0.9. The samples were analyzed using a digital densimeter. The results showed that glycerol was effective to promote ethanol dehydration and the presence of an azeotrope was not observed using a solvent to feed ratio (S/F equal to 0.9. Some empirical correlations were investigated to evaluate the HETP (Height Equivalent to a Theoretical Plate, and the results provided a useful tool for designing a packed bed column for ethanol-water separation.

  7. Simulation of ethanol extractive distillation with mixed glycols as separating agent

    Directory of Open Access Journals (Sweden)

    I. D. Gil

    2014-03-01

    Full Text Available Extractive distillation is an alternative for ethanol dehydration processes that has been shown to be more effective than azeotropic distillation and, in close proximity, to be very competitive against the process that uses adsorption with molecular sieves. Glycols have been shown to be the most effective solvents in extractive distillation, mainly ethylene glycol and glycerol. In this work, an extractive distillation column was simulated with the Aspen Plus software platform, using the RadFrac module for distillation columns, to investigate the effect on the separation of the ethylene glycol-glycerol mixture composition, the separating agent feed stages, the separating agent split stream feed, and the azeotropic feed temperature. The NRTL model was used to calculate the phase equilibrium of these strongly polar mixtures. A rigorous simulation of the extractive distillation column finally established was also performed, including a secondary recovery column for the mixture of solvents and a recycle loop, to simulate an industrially relevant situation. This simulation allowed establishing the complete parameters to dehydrate ethanol: the optimal stage for separating agent feed is stage 4; the most adequate composition for the glycols mixture is 60 mol% ethylene glycol and 40 mol% glycerol. Finally, energetically efficient operating conditions for each one of the columns were established through a preliminary pinch analysis.

  8. The Role of Molecule Clustering by Hydrogen Bond in Hydrous Ethanol on Laminar Burning Velocity

    Directory of Open Access Journals (Sweden)

    I Made Suarta

    2016-01-01

    Full Text Available The role of hydrogen bond molecule clustering in laminar burning velocities was observed. The water in hydrous ethanol can change the interaction between water-ethanol molecules. A certain amount of water can become oxygenated which increases the burning velocity. The hydrogen bond interaction pattern of ethanol and water molecules was modeled. Based on the molecular model, azeotropic behavior emerges from ethanol-water hydrogen bond, which is at a 95.1%v composition. The interaction with water molecule causes the ethanol molecule to be clustered with centered oxygenated compound. So, it supplies extra oxygen and provides intermolecular empty spaces that are easily infiltrated by the air. In the azeotropic composition, the molecular bond chain is the shortest, so hypothetically the burning velocity is anticipated to increase. The laminar burning velocity of ethanol fuel was tested in a cylindrical explosion bomb in lean, stoichiometric, and rich mixtures. The experimental result showed that the maximum burning velocity occurred at hydrous ethanol of 95.5%v composition. This discrepancy is the result of the addition of energy from 7.7% free ethanol molecules that are not clustered. At the rich mixture, the burning velocity of this composition is higher than that of anhydrous ethanol.

  9. Adaptation of systems to fluid changes; Adaptation des systemes aux changements de fluides

    Energy Technology Data Exchange (ETDEWEB)

    Clodic, D. [Ecole Nationale Superieure des Mines, 75 - Paris (France)

    1996-12-31

    Regulation constraints and the stoppage of CFCs production and HCFCs production in the future lead to rapid evolutions in the conceiving of refrigerating installations which are linked with refrigerant changes. The refrigerant/installation pair has become the aim of detailed analyses in order to understand the relation between the thermodynamical properties of fluids and the energy efficiency of refrigerating installations. The efficiency depends entirely on the global design of the installation while the choice of the fluid is only one element that contributes to this efficiency. This paper analyzes successively: the consequences of pure refrigerant substitution on volume and centrifugal compressors, and the constraints linked with the use of mixtures close to azeotropic compounds (R408A and R404A) and mixtures with temperature shift like R407C. In this last case, the replacement is deeply different in the case of water heat exchangers and in the case of air-circulation heat exchangers. (J.S.) 3 refs.

  10. Novel one-pot one-step synthesis of 2'-[{sup 18}F]fluoroflumazenil (FFMZ) for benzodiazepine receptor imaging

    Energy Technology Data Exchange (ETDEWEB)

    Young, Hyun Yoon; Jae, Min Jeong E-mail: jmjng@snu.ac.kr; Hyung, Woo Kim; Sung, Hyun Hong; Lee, Yun-Sang; Hee, Sup Kil; Dae, Yoon Chi; Dong, Soo Lee; Chung, June-Key; Myung, Chul Lee

    2003-05-01

    We describe the synthesis of 2'-[{sup 18}F]fluoroflumazenil (FFMZ), which differs from the typically used [{sup 18}F]fluoroethylflumazenil (FEFMZ) for benzodiazepine receptor imaging. For one-pot one-step labeling, the precursors, 2'-tosyloxyflumazenil (TFMZ) and 2'-mesyloxyflumazenil (MFMZ), were synthesized in three steps. The precursors were successfully labeled with no-carrier-added {sup 18}F-fluoride which was activated by repeated azeotropic distillation with Kryptofix 2.2.2./potassium carbonate in MeCN. An automated system for labeling and purification of [{sup 18}F]FFMZ was developed. Labeling efficiency and radiochemical purity of [{sup 18}F]FFMZ after synthesis by the automated system were 68% and 98%, respectively. Specific binding of [{sup 18}F]FFMZ to central benzodiazepine receptor of rats was demonstrated by phosphoimaging.

  11. Synthesis and Characterization of Some Trivalent and Tetravalent Derivatives of 2- Hydroxy-1-naphthoic Acid

    Directory of Open Access Journals (Sweden)

    Deepti Joshi

    2004-01-01

    Full Text Available The trivalent derivatives (B, Al, As, Sb & Fe and tetravalent derivatives (Si, Ti & Se of 2-hydroxy-1-naphthoic acid have been prepared by the interaction of their corresponding isopropoxide with letter in different molar ratio viz. 1:3 &1:4 in benzene medium. The prepared compounds generally obtained as coloured solids and amongst them those containing isopropoxy groups were found to be hygroscopic. All these compound were characterized by azeotrope and elemental analysis as well as by IR, PMR and mass spectral measurements. These spectral data have facilitated in elucidating the mode of bonding of the said metals and non-metals in these compounds with 2-hydroxy-1-naphthoic acid.

  12. On the Integration Role of Solvents in Process Synthesis-Design-Intensification: Application to DMC/MeOH separation

    DEFF Research Database (Denmark)

    Gani, Rafiqul; Babi, Deenesh Kavi

    2015-01-01

    and the heavier boiling compound is obtained as the top product of the second distillation column where the solvent is recovered (for re-use and recycle). Therefore, the solvent design problem can be defined as follows, given an azeotropic mixture to be separated into two pure streams that utilizes a mass...... separating agent, find the best (optimal or near-optimal) solvent candidate (or mixture) that can perform the separation subject to economic, environmental and thermo-physical property constraints. This design problem inherently is a mixed integer non-linear programming problem because the property...... design problem into manageable sub-problems. In the first stage, a number of solvent candidates are generated based on pre-defined structural constraints, for example, acyclic, cyclic and/or aromatic compounds, etc. In the second stage, the solvent candidates are screened using property constraints...

  13. Asymmetric Transfer Hydrogenation of Imines in Water by Varying the Ratio of Formic Acid to Triethylamine.

    Science.gov (United States)

    Shende, Vaishali S; Deshpande, Sudhindra H; Shingote, Savita K; Joseph, Anu; Kelkar, Ashutosh A

    2015-06-19

    Asymmetric transfer hydrogenation (ATH) of imines has been performed with variation in formic acid (F) and triethylamine (T) molar ratios in water. The F/T ratio is shown to affect both the reduction rate and enantioselectivity, with the optimum ratio being 1.1 in the ATH of imines with the Rh-(1S,2S)-TsDPEN catalyst. Use of methanol as a cosolvent enhanced reduction activity. A variety of imine substrates have been reduced, affording high yields (94-98%) and good to excellent enantioselectivities (89-98%). In comparison with the common azeotropic F-T system, the reduction with 1.1/1 F/T is faster.

  14. Prospects for the Production of Liquid Biofuels in Ukraine

    Energy Technology Data Exchange (ETDEWEB)

    Zhelyezna, T.; Geletukha, G. [SEC ' Biomass' , Kiev (Ukraine)

    2006-07-15

    Ukraine is highly dependent on imported energy carriers. Prices of motor fuels permanently trend to rising. On the other hand, Ukraine has all necessary preconditions to start wide production of motor fuels from biomass for internal usage and export abroad. Ukrainian specialists have developed effective technology for production of high-octane oxygen containing admixture to petrol, which is the local analogue of bio-ethanol. For dewatering ethyl alcohol they use azeotropic distillation and adsorption on molecular sieves (zeolites). The technology is implemented at a number of distilleries of Ukraine. Besides, a few enterprises are about to start commercial production of bio-diesel in the country. The main barriers here are absence of clear state policy on the matter, lack of state support and sometimes still old way of thinking.

  15. ARTI Refrigerant Database

    Energy Technology Data Exchange (ETDEWEB)

    Calm, J.M.

    1992-11-09

    The database provides bibliographic citations and abstracts for publications that may be useful in research and design of air- conditioning and refrigeration equipment. The database identifies sources of specific information on R-32, R-123, R-124, R-125, R-134, R-134a, R-141b, R-142b, R-143a, R-152a, R-245ca, R-290 (propane), R- 717 (ammonia), ethers, and others as well as azeotropic and zeotropic and zeotropic blends of these fluids. It addresses lubricants including alkylbenzene, polyalkylene glycol, ester, and other synthetics as well as mineral oils. It also references documents on compatibility of refrigerants and lubricants with metals, plastics, elastomers, motor insulation, and other materials used in refrigerant circuits. A computerized version is available that includes retrieval software.

  16. Refrigerating machine operating characteristics under various mixed refrigerant mass charges

    Energy Technology Data Exchange (ETDEWEB)

    Rozhentsev, Andrey [Far Eastern State Transport University of the Russian Federation, Seryshev street, 47, 680021 Khabarovsk (Russian Federation)

    2008-11-15

    This paper reports the results of experimental investigation of a low-temperature Joule-Thomson refrigerating machine, working by use of a non-azeotropic mixture of refrigerants and with a single-stage hermetic compressor. The temperature, hydraulic and power performance of the machine are determined experimentally in relation to the mixed refrigerant (MR) mass charge. Variations of the MR refrigerating machine operating performance with the working mixture mass charge are found to be considerably different from the analogous performance variations of a refrigerating machine charged with a pure refrigerant. The peculiarities of those relationships are analyzed theoretically. The specific value of a minimum acceptable MR mass charge for the investigated system and its correlation with internal processes in the machine loop are established as well. If the refrigerant mixture mass charges are below the minimum ones, the temperature and power performance of the MR machine differ essentially from the design performance and such operating modes are considered inadmissible. (author)

  17. The radiochemistry of [{sup 18} F]-FDG: the first experience in Mexico; La radioquimica del [{sup 18} F]-FDG: la primera experiencia en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Lopez D, F.A. [Unidad PET-Ciclotron, Facultad de Medicina, UNAM, Av. Universidad 3000, Ciudad Universitaria, Coyoacan, 04500 Mexico, D. F. (Mexico)]. e-mail: fred-alonso@correo.unam.mx

    2004-07-01

    The present work describes the more used method for the synthesis of 2 - [{sup 18} F] - fluorine-2-deoxy-D-glucose that is the more used radiopharmaceutical in the nuclear medicine in the cancer diagnostic. The process consists on two chemical reactions: i) [{sup 18} F{sup -}] - nucleophilic radio fluorination and i i) a hydrolysis catalyzed by acid. The first reaction incorporates to the [{sup 18} F]- fluorine labelled inside the organic precursor 1,3,4,6-tetra- O -acetil-2- O-trifluoromethanesulfonyl- {beta}-D-mannopyranose (triflate of mannose). The mechanism of this reaction is a bimolecular nucleophilic substitution (SN{sub 2}) with the ion [{sup 18} F{sup -}] - fluoride; in the second reaction, the hydrolysis of those protective acetyl groups generate the hydroxyl groups free of the [{sup 18} F]-FDG. The process includes an azeotropic distillation and several purification steps. (Author)

  18. Fluorocarbon Adsorption in Hierarchical Porous Frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Motkuri, Radha K.; Annapureddy, Harsha V.; Vijayakumar, M.; Schaef, Herbert T.; Martin, P F.; McGrail, B. Peter; Dang, Liem X.; Krishna, Rajamani; Thallapally, Praveen K.

    2014-07-09

    The adsorption behavior of a series of fluorocarbon derivatives was examined on a set of microporous metal organic framework (MOF) sorbents and another set of hierarchical mesoporous MOFs. The microporous M-DOBDC (M = Ni, Co) showed a saturation uptake capacity for R12 of over 4 mmol/g at a very low relative saturation pressure (P/Po) of 0.02. In contrast, the mesoporous MOF MIL-101 showed an exceptionally high uptake capacity reaching over 14 mmol/g at P/Po of 0.4. Adsorption affinity in terms of mass loading and isosteric heats of adsorption were found to generally correlate with the polarizability of the refrigerant with R12 > R22 > R13 > R14 > methane. These results suggest the possibility of exploiting MOFs for separation of azeotropic mixtures of fluorocarbons and use in eco-friendly fluorocarbon-based adsorption cooling and refrigeration applications.

  19. Conceptual design of distillation-based hybrid separation processes.

    Science.gov (United States)

    Skiborowski, Mirko; Harwardt, Andreas; Marquardt, Wolfgang

    2013-01-01

    Hybrid separation processes combine different separation principles and constitute a promising design option for the separation of complex mixtures. Particularly, the integration of distillation with other unit operations can significantly improve the separation of close-boiling or azeotropic mixtures. Although the design of single-unit operations is well understood and supported by computational methods, the optimal design of flowsheets of hybrid separation processes is still a challenging task. The large number of operational and design degrees of freedom requires a systematic and optimization-based design approach. To this end, a structured approach, the so-called process synthesis framework, is proposed. This article reviews available computational methods for the conceptual design of distillation-based hybrid processes for the separation of liquid mixtures. Open problems are identified that must be addressed to finally establish a structured process synthesis framework for such processes.

  20. Physico-chemistry in distillation process of BiCl3 -HCl-H2 O system

    Institute of Scientific and Technical Information of China (English)

    郑国渠; 唐谟堂

    2002-01-01

    The gas-liquid equilibrium and evaporation behaviors of HCl and H2O in the distillation process of the BiCl3-HCl-H2O ternary system were investigated. With increasing content of BiCl3, the quasi-azeotropic point moves toward the low acidity and high temperature. The evaporation law of HCl and H2O in low-acidity BiCl3 solution was summarized. The residue phases were studied as well. The results show that the residue phases vary with the distillation temperature, namely BiCl3 and BiCl3*xHCl at low temperature and BiCl3 and BiOCl exist at higher temperature. The causes for the formation of different residue phases were discussed.

  1. Profitability increase of alcohol distilleries by the rational use of sub-products

    Energy Technology Data Exchange (ETDEWEB)

    Haandel, Adrianus C. van; Catunda, Paula F.C. [Paraiba Univ., Joao Pessoa, PB (Brazil). Dept. de Engenharia Civil

    1993-12-31

    Industrial alcohol production in Brazil is based on fermentation of sugar cane juice. After concentration and distillation, azeotropic alcohol is obtained along with four side streams. The profitability of alcohol distilleries could be improved by a more rational use of side stream products. An alternative for improved energy production is to abandon alcohol fermentation and apply anaerobic digestion directly to vegetal energy source. In that case the useful energy production is much higher and can be obtained using much simpler equipment. More importantly, the source for energy production would no longer be restricted to sugar cane, but other crops, notably those produced in the drier hinterland of Northeast Brazil could also de used for this purpose. 3 figs., 1 tab.

  2. Measurement and Correlation of Vapor-Liquid Equilibrium for Binary System 1,2-Epoxycyclohexane+1,2-Dichloroethane

    Institute of Scientific and Technical Information of China (English)

    周彩荣; 王海峰; 石晓华; 蒋登高

    2013-01-01

    Vapor-liquid equilibrium data (T, x, y) of binary system 1,2-epoxycyclohexane+1,2-dichloroethane were determined experimentally by using a modified ROSE-Williams equilibrium vaporization system at 101.33 kPa. The results show that this binary system does not have azeotropic point. The vapor-liquid equilibrium data are in thermodynamic consistency. The binary interaction parameters in the Wilson equation are presented with the correlation of vapor-liquid equilibrium data. The measurements of liquid phase composition and bubble point tem-perature are well represented by the Wilson equation. Values of vapor molecular fractions and activity coefficients from the Wilson equation are presented. This work provides important engineering data for the separation of 1,2-dichloroethane and 1,2-epoxycyclohexane .

  3. Preparation of tetragonal CaO-ZrO2 nano-powder by chemical coprecipitation method

    Institute of Scientific and Technical Information of China (English)

    刘建本; 阮建明; 邹俭鹏; 李亚军; 骆锋

    2003-01-01

    With zirconium oxychloride, nitrate of lime and ammonia as raw materials, nano-powder of CaO-ZrO2 was prepared by chemical coprecipitation method. By use of azeotropic distillation processing, chemical coprecipitation precursor was obtained. Phase transformation of the precursor was observed at the temperature of 593.81 ℃ and 1 234.56 ℃ respectively with DTA analyses. Phase structure was analyzed through XRD and Raman spectra. The average particle size of tetragonal zirconium oxide powder was 9.8 and 43.7 nm after calcination at 600 and 1 100 ℃ respectively which was tested by TEM and BET analyses. Furthermore, the influences of the doping of nitrate of lime and the average particle size of zirconium oxide on the stability of tetragonal zirconium oxide were also discussed.

  4. Sample preparation for semivolatile organics analysis of Hanford single-shell tank waste with high nitrate/nitrite and water content

    Energy Technology Data Exchange (ETDEWEB)

    Stromatt, R.W.; Hoppe, E.W.; Steele, M.J.

    1993-11-01

    This report describes research work carried out to solve sample preparation problems associated with applying gas chromatography with mass spectrometric detection (GC/MS) to the analysis of single shell tank (SST) samples from Hanford for semivolatile organic compounds. Poor performance was found when applying the procedures based on the U.S. Environmental Protection Agency (EPA), Contract Laboratory Program, Statement of Work (CLP SOW). Analysis work was carried out on simulated drainable liquid modeled after the SST core samples which had evidenced analysis problems. Some work was also conducted on true SST samples. It was found that the pH range was too broad in the original procedure. It was also found that by decreasing the amount of methanol used in the extraction process, problems associated with the formation of an azeotrope phase could be avoided. The authors suggest a new procedure, whose eventual application to a wide array of SST samples will lend itself to better quality control limits.

  5. Development of {sup 77}Ge/{sup 77}As parent-daughter system for periodic removal of {sup 77}As for environmental sanitation and biochemical purposes

    Energy Technology Data Exchange (ETDEWEB)

    Olah, Zita; Doczi, Rita [Budapest Univ. of Technology and Economics (Hungary). Inst. of Nuclear Techniques; Szuecs, Zoltan [Hungarian Academy of Sciences, Debrecen (Hungary). Inst. for Nuclear Research; Varga, Zoltan [Hungarian Academy of Sciences, Budapest (Hungary). Research Centre for Natural Sciences

    2015-07-01

    A simple method was developed for the separation of radioactive {sup 77}As from neutron irradiated natural GeO{sub 2} samples for environmental and biochemical studies. The method is based on the volatility of GeCl{sub 4}. The GeCl{sub 4} was co-evaporated from the reaction mixture with an azeotropic mixture of HCl and water, and immediately condensed into a separate finger part of the special glass apparatus which was cooled by liquid nitrogen. By inverting the room temperature and the deep frozen parts of the glass equipment after three half-lives of the {sup 77}Ge the separation process can be repetitive, getting a special type of {sup 77}Ge/{sup 77}As parent-daughter system. The radionuclidic purity of the remaining As fraction was found to be 99.95%. Its yield, however, drastically decreased in the second and subsequent separations.

  6. 以苯胺为溶剂间歇萃取精馏分离甲醇-乙腈%Separation of methanol-acetonitrile by batch extractive distillation with aniline as solvent

    Institute of Scientific and Technical Information of China (English)

    于洋; 白鹏; 李广忠; 尹琨; 庄琼红

    2012-01-01

    提出和研究了以苯胺作为溶剂的甲醇-乙腈间歇萃取精馏分离工艺。根据溶剂极性相似相溶原理,结合ChemCAD软件模拟汽液平衡和汽液平衡实验确定苯胺为合适的溶剂。结果表明,不仅苯胺能够消除甲醇-乙腈物系的共沸现象,效果优于N,N-二甲基甲酰胺(DMF),而且可以采用Wilson模型对苯胺作为溶剂的甲醇-乙腈共沸物系汽液平衡进行模拟。通过实验考察了间歇萃取精馏的分离效果。采用有33块理论板的填料塔进行间歇萃取精馏甲醇-乙腈共沸混合物分离实验,其中净化回收段填料层3块理论板,萃取精馏段填料层30块理论板,回流比为4,苯胺作为溶剂,溶剂质量比为2.5∶1时,在塔顶得到产品甲醇质量分数为98.97%,高于DMF作为溶剂时的95.76%;表明苯胺更加适合作为萃取精馏分离甲醇-乙腈共沸物系的溶剂。%In this paper,aniline was proposed as the solvent for the separation of the azeotrope methanol-acetonitrile by batch extractive distillation and the process was studied.Aniline was selected as the suitable solvent on the basis of the law of similarity and dissolvability,combined with VLE simulation by ChemCAD software and the VLE experiments.The results show that aniline as the solvent could break the azeotrope and the effects of aniline were better than N,N-dimethylformamide(DMF).The Wilson model was used in VLE simulation.The experiment on the separation of the azeotrope methanol and acetonitrile by batch extractive distillation was carried out with a packed column with 33 theoretical plates among which 3 theoretical plates are in rectifying and recovery section and 30 theoretical plates in extractive distillation section.With the reflux ratio of 4,and the solvent mass ratio of 2.5∶1,the product purity of methanol reaches 98.97%,which is higher than the value of 95.76% when DMF was used as the solvent.It indicates that the extractive distillation with aniline as

  7. Separation of methanol-acetonitrile by extractive distillation%萃取精馏分离甲醇-乙腈的研究

    Institute of Scientific and Technical Information of China (English)

    于洋; 白鹏; 庄琼红

    2011-01-01

    为了分离甲醇-乙腈共沸混合物,研究了萃取精馏在甲醇-乙腈共沸物系中的应用.通过溶剂极性比较初选出萃取精馏溶剂,由ChemCAD软件模拟和气液平衡实验验证选定出合适的溶剂用于萃取精馏分离甲醇-乙腈共沸混合物,通过萃取精馏实验考察了所选萃取精馏溶剂的效果.结果表明:N,N-二甲基甲酰胺(DMF)能够消除甲醇-乙腈共沸物系的共沸.采用Wilson模型对常压下甲醇-乙腈物系和加入溶剂N,N-二甲基甲酰胺的汽液平衡进行模拟,模拟数据与实验结果吻合较好.采用有33块理论板,其中净化回收段填料层3块理论板,萃取精馏段填料层30块理论板的填料塔进行间歇萃取精馏实验分离甲醇-乙腈共沸混合物,回流比为4,溶剂质量比为3∶1时在塔顶得到产品甲醇质量分数为95.76%.说明N,N-二甲基甲酰胺作为溶剂的萃取精馏分离甲醇-乙腈共沸混合物是可行的.%In order to separate methanol-acetonitrile azeotropic mixture, the application of extractive distillation to separation of methanol-acetonitrile was researched.By comparing solvent polarity, the simulation by ChemCAD software and VLE experiment were used to select the suitable solvent for the separation of methanol-acetonitrile azeotropic mixture by extractive distillation.The effectiveness of the solvent selected was investigated by the extractive distillation experiments.The results show that N,N-dimethyfformamide (DMF) as solvent can break the azeotrope ot methanol-acetonitrile system.Wilson model was used in the simulation of the VLE of methanol-acetonitrile system as well as when DMF was added under atmospheric pressure.The simulation data agree well with the experimental results.The experiment of separation of azeotropic mixture of methanol and acetonitrile by batch extractive distillation was carried out in a packed column of 33 theoretical plates.The purification and recovery section has 3 theoretical plates and

  8. Boiling heat transfer correlations for refrigerant mixtures flowing inside micro-fin tubes

    Institute of Scientific and Technical Information of China (English)

    Xiaoyan ZHANG; Xingqun ZHANG; Yunguang CHEN; Xiuling YUAN

    2008-01-01

    Based on experimental results of ternary non-azeotropic refrigerant mixture R417A flowing and boiling in one smooth and two internally grooved horizontal tubes with different geometrical parameters, a boiling heat transfer correlations was developed for refrigerant mix-tures flowing inside micro-fin tubes by applying the enhancement factor in the present modified-Kattan model which was modified by the experimental data of R417A in a smooth tube. The comparison between the calculation and the experimental results indicates that the prediction by the present correlations is in good agreement with the experiment of refrigerant mixtures inside different micro-fin tubes with a standard deviation of ± 30% for vapor qualities below 80%.

  9. STUDIES ON REGULARITY OF POLY PHENYLSILSESQUIOXANE CHAINS

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xinsheng; CHEN Suming; SHI Lianghe

    1987-01-01

    IR and 29Si NMR were used to determine the structures of ladderlike polymer polyphenylsilsesquioxanes (PPS). It was found that PPS with lots of defects had a wide and strong absorption band in 1000-1400 cm- 1 with only one sharp peak at 1137 cm- 1 while two peaks (1130 and 1045 cm- 1) were observed for PPS with perfect ladderlike structure. Branching and crosslinking of PPS lead to the reduction of 1045cm- 1 peak. 29Si NMR spectra, however, showed two peaks (δ = -78 ppm and -87 ppm when δHMDs = 0 ppm) for defective or branched PPS. The -87 ppm peak is related to the ladderlikely constructed Si atoms and -78 ppm corresponds to defective Si atoms. PPS with defects less than 0.1% chain units was obtained by azeotropic polycondensations.

  10. Synthesis and characterization of three-arm star-shaped polyethylene glycols with 1,1,1-trihydroxmethylpropane as cores

    Institute of Scientific and Technical Information of China (English)

    Kangcheng WANG; Wei HUANG; Yongfeng ZHOU; Deyue YAN

    2008-01-01

    A small molecule core (TMP,SK3) with three terminal carboxyl groups was synthesized successfully by the reaction of 1,1,1,trihydroxymethylpropane with the excessive sebacic acid diacetic anhydride (SK). Then, the core molecule was used as a coupling agent to condensate with polyethylene glycols (PEG) of different molecular weights or polyethylene glycol monomethyl ether (PEGm) in the presence of stannous octoate as catalyst and diphenyl ether as an azeotropic agent to remove water. Thus, the three,arm star,shaped PEGs was obtained successfully and characterized by IH,NMR,DSC, GPC and XRD etc. DSC measurements indicate that the crystallizing and the melting temperatures of the three,arm star,shaped PEGs were different from those of the corresponding linear PEG because the existence of TMP,SK3 altered its crystallizing velocity and perfect degree of crystallization.

  11. Separation of Primary Alcohols and Saturated Alkanes from Fisher-Tropsch Synthesis Products

    Institute of Scientific and Technical Information of China (English)

    Suqiao Li; Zhongli Tang⁎; Fujun Zhou; Wenbin Li; Xigang Yuan

    2014-01-01

    abstract A method for separating primary alcohols and saturated alkanes from the products of Fisher-Tropsch synthesis is developed. The separation scheme consists of three steps:(1) the raw material is pre-separated by fractional distillation into four fractions according to normal boiling points;(2) appropriate extractants are selected to sep-arate the primary alcohols from the saturated alkanes in each fraction;(3) the extractants are recovered by azeotropic distillation and the primary alcohols in the extract phase are purified. Based on the proposed method, the total recovery rates of the primary alcohols and the saturated alkanes are 86.23%and 84.62%respectively. © 2014 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. Al rights reserved.

  12. Phase diagrams of binary crystalline-crystalline polymer blends.

    Science.gov (United States)

    Matkar, Rushikesh A; Kyu, Thein

    2006-08-17

    A thermodynamically self-consistent theory has been developed to establish binary phase diagrams for two-crystalline polymer blends by taking into consideration all interactions including amorphous-amorphous, crystal-amorphous, amorphous-crystal, and crystal-crystal interactions. The present theory basically involves combination of the Flory-Huggins free energy for amorphous-amorphous isotropic mixing and the Landau free energy of polymer solidification (e.g., crystallization) of the crystalline constituents. The self-consistent solution via minimization of the free energy of the mixture affords determination of eutectic, peritectic, and azeotrope phase diagrams involving various coexistence regions such as liquid-liquid, liquid-solid, and solid-solid coexistence regions bound by liquidus and solidus lines. To validate the present theory, the predicted eutectic phase diagrams have been compared with the reported experimental binary phase diagrams of blends such as polyethylene fractions as well as polycaprolactone/trioxane mixtures.

  13. Aluminium nitride: from the powder to the substrate. Le nitrure d'aluminium: de la poudre au substrat

    Energy Technology Data Exchange (ETDEWEB)

    Jarrige, J. (Lab. de Ceramiques Nouvelles, Limoges (France)); Mexmain, J. (Lab. de Ceramiques Nouvelles, Limoges (France)); Oumaloul, M. (Lab. de Ceramiques Nouvelles, Limoges (France)); Bachelard, R. (CRRA ELF ATOCHEM, Pierre Benite (France)); Disson, J.P. (CRRA ELF ATOCHEM, Pierre Benite (France))

    1993-04-01

    The aluminium nitride is a material which should replace alumina or beryllia as substrate for power electronic applications. The powder, prepared by carbothermal nitridation, is dispersed in a butanone-2-ethanol azeotrop solvent with a phosphate ester. Electrical conductivity, sedimentation, viscosity have been used to determine which phenomena take place in the defloculation of the suspension. The stability of AlN suspensions is due mainly to an electrostatic mechanism, with a steric contribution. The aluminium nitride tape-casting slip has been sintered at 1850 C in a nitrogen atmosphere. Removing of the binder and plasticizer can be performed in the same oven at 650 C, due to their nature and low concentration. The thermal conductivity of the substrates has been measured and is in the 160 to 200 W/m.K range. (orig.).

  14. Preparation,characterization and comparison of nanometer tin oxide powder by various methods%纳米二氧化锡的多种方法制备、表征及其对比

    Institute of Scientific and Technical Information of China (English)

    张倩瑶; 苑媛; 刘金鑫; 龚晓钟

    2012-01-01

    本文采用共沸蒸馏法、水热法、溶胶-凝胶法分别制备纳米SnO2粉体,所制得的SnO2粉体利用X-射线衍射(XRD)和扫描电子显微镜(SEM)表征.结果表明,3种方法制备得的粉体均为四方金红石结构,共沸蒸馏法所得粉体平均颗粒约为20nm.水热法所得粉体的平均颗粒约为10nm.溶胶-凝胶法所得粉体的平均颗粒约为70nm.研究不同制备方法合成纳米SnO2粉体在合成工艺,生产周期,产物颗粒大小等方面的优缺点.%In this paper, Nanometer Tin Oxide Powders was synthesized with three methods by azeotropic distillation,sol-gel technique and hydrothermal synthesis. The obtained nano-particle was characterized by X-ray difrraction(XRD) and scanning electron microscopy(SEM). Hie results showed that the namometer tin oxide par-ticle vrere tetragonal nitile structure. The size of particles which synthesized by azeotropic distillation was about 20nm and which prepared by hydrothermal method wans about 10nm. The diameter of the particles synthesized by sol-gel technique are up to 10nm. The advantages and disadvantage of prepared by different aynthetic methods in synthesis technology,productive cost,the size of the produtive particles were studied.

  15. Phase equilibrium properties of binary aqueous solutions containing ethanediamine, 1,2-diaminopropane, 1,3-diaminopropane, or 1,4-diaminobutane at several temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Nouria Chiali-Baba [LATA2M, Laboratoire de Thermodynamique Appliquee et Modelisation Moleculaire, University AbouBekr Belkaid of Tlemcen, P.O. Box 119, Tlemcen 13000 (Algeria); Negadi, Latifa, E-mail: l_negadi@mail.univ-tlemcen.d [LATA2M, Laboratoire de Thermodynamique Appliquee et Modelisation Moleculaire, University AbouBekr Belkaid of Tlemcen, P.O. Box 119, Tlemcen 13000 (Algeria); Mokbel, Ilham; Jose, Jacques [LSA, Laboratoire des Sciences Analytiques, CNRS-UMR 5180, Universite Claude Bernard - Lyon I. 43, Bd du 11 Novembre 1918, Villeurbanne Cedex 69622 (France)

    2011-05-15

    Research highlights: Vapour pressures of ethanediamine (EDA), 1,2-diaminopropane, 1,3-diaminopropane (1,3-DAP), or 1,4-diaminobutane (1,4-DAB) aqueous solutions are reported between (293 and 363) K. The two first mixtures show negative azeotropic behaviour. The aqueous solutions of EDA, 1,2-DAP, or 1,3-DAP exhibit negative G{sup E} whereas the one containing 1,4-DAB shows either negative G{sup E} or sinusoidal shape for G{sup E}. - Abstract: The vapour pressures of {l_brace}ethanediamine (EDA) + water{r_brace}, {l_brace}1,2-diaminopropane (1,2-DAP) + water{r_brace}, {l_brace}1,3-diaminopropane (1,3-DAP) + water{r_brace} or {l_brace}1,4-diaminobutane (1,4-DAB) + water{r_brace} binary mixtures, and of pure EDA, 1,2-DAP, 1,3-DAP, 1,4-DAB, and water components were measured by means of two static devices at temperatures between (293 and 363) K. The data were correlated with the Antoine equation. From these data, the excess Gibbs function (G{sup E}) was calculated for several constant temperatures and fitted to a fourth-order Redlich-Kister equation using the Barker's method. The {l_brace}ethanediamine (EDA) + water{r_brace}, and {l_brace}1,2-diaminopropane (1,2-DAP) + water{r_brace} binary systems show negative azeotropic behaviour. The aqueous solutions of EDA, 1,2-DAP, or 1,3-DAP exhibit negative deviations in G{sup E} for all investigated temperatures over the whole composition range whereas the (1,4-DAB + water) binary mixture shows negative G{sup E} for temperatures (293.15 < T/K < 353.15) and a sinusoidal shape for G{sup E} at T = 363.15 K.

  16. Use of KLEA 407A in systems with a flooded evaporator; Verwendung von KLEA 407A bei ueberfluteter Verdampfung

    Energy Technology Data Exchange (ETDEWEB)

    Low, B.; Taylor, A.

    1996-08-01

    One consequence of the phasing-out of CFCs and the legislation for the control of HCFCs was the introduction of zeotropic refrigerants in the market. These consist of two or more components, in order to achieve a balanced profile of characteristics. Examples are: R 401A, which was developed as a transition substitute for R 12, and R 407A as well as R 407C, which are alternatives for R 502 and R 22. Most of the practical experience gained so far with these refrigerants was gathered in systems with dry evaporation. In such systems, the refrigerant mixtures behave in many regards like a single-component refrigerant or an azeotropic refrigerant. The main difference consists in the fact that a zeotropic refrigerant has a characteristic rise in temperature during evaporation. This phenomenon is well-studied meanwhile. In machinery with dry evaporation it has been found to be no problem. Indeed, there now exist systems that benefit by this temperature rise. (orig.) [Deutsch] Eine Folge des Ausstiegs aus FCKW und der Gesetze zur Kontrolle von HFCKW war die Markteinfuehrung zeotroper Kaeltemittel. Diese bestehen aus zwei oder mehreren Komponenten, um ein ausgewogenes Eigenschaftsprofil zu erzielen. Beispiele sind R 401 A, das als Zwischenloesung fuer R 12 entwickelt wurde, sowie R 407 A und R 407 C, Alternativen fuer R 502 und R 22. Die meisten praktischen Erfahrungen mit solchen Kaeltemitteln konzentrierten sich bisher auf Anlagen mit trockener Verdampfung. In solchen Anlagen verhaelt sich das Kaeltemittelgemisch in vielerlei Hinsicht wie ein Einstoff- oder ein azeotropes Kaeltemittel. Der Hauptunterschied besteht darin, dass ein zeotropes Kaeltemittel einen charakteristischen Temperaturgleit oder Temperaturanstieg waehrend des Verdampfungsprozesses zeigt. Dieses Phaenomen ist heute gut untersucht. Bei Anlagen mit Trockenverdampfung hat es sich als nicht problematisch herausgestellt. In der Tat stehen heute Anlagen zu Verfuegung, die sich diesen Temperaturgleit sogar

  17. Flowsheet Simulation and Parameter Analysis of Separating BenzeneCyclohexane by Batch Extractive Distillation%间歇萃取精馏分离苯-环己烷的流程模拟及参数分析

    Institute of Scientific and Technical Information of China (English)

    李文秀; 贾庆波; 张志刚; 连利燕; 刘雷

    2012-01-01

    In the chemical industry, benzene-cyclohexane mixture is very typical binary azeotrope. In this paper, dimethylsulfoxide(DMSO) and N-methylpyrrolidone(NMP) (DMSO : NMP=1 : 3) were used as the mixed solvent, based on previous experimental validation, a BatchFrac unit operation block in ASPEN PLUS 11.1 was adopted, simulation calculation of the batch extractive distillation for the separation of binary azeotropic benzene-cyclohexane mixture was carried out by choosing UNIFAC as the calculation method of physical property and by changing operation parameters. The simulation results show that the mass rate of overhead cyclohexane is up to 98%. The application of simulation calculation can provide a good theoretical basis for deep study and design reference.%苯和环己烷混合物是化工中非常典型的二元共沸物系.选用二甲基亚砜( DMSO)和N-甲基吡咯烷酮(NMP)的质量配比为DMSO∶NMP=1∶3作为混合溶剂,在前期实验验证基础上,采用ASPEN PLUS11.1化工模拟软件中的BatchFrac单元操作模块,采用UNIFAC物性计算方法,通过改变各操作参数,对苯和环己烷二元共沸物系的分离进行间歇萃取精馏模拟计算.模拟结果表明:常压操作条件下,塔顶环己烷质量分率可达到98%,模拟计算的运用能够为实验进一步研究提供很好的理论依据和设计参考.

  18. 以N,N-二甲基甲酰胺为溶剂萃取精馏制备高纯度甲缩醛%Preparation of high purity methylal by extractive distillation using N,N-dimethylformamide (DMF) as solvent

    Institute of Scientific and Technical Information of China (English)

    尹琨; 蒋建兰; 白鹏; 唐克; 姜占坤

    2011-01-01

    The solvent for methylal production by extractive distillation was chosen according to basic selection rules. The appropriate solvent and solvent ratio were determined with Chemcad simulation and vapor-liquid equilibrium experiment. The results showed that N,N-dimethylformamide (DMF) as a solvent could eliminate the azeotropic point of the azeotrope methylal-methanol. The simulation of vapor-liquid equilibrium using UNIQUAC model for methylal-methanol system with and without DMF under atmospheric pressure were performed and the simulation results agreed well with the experimental data. Finally the separation of crude product of methylal-methanol by batch extractive distillation was performed. Under the operation conditions, the high purity product methyal of 99.9% (mass percentage) could be obtained at the top of the column .%通过溶剂选择原理粗选出萃取精馏制备甲缩醛产品的溶剂,既而通过Chemcad软件模拟和汽液平衡实验确定合适的溶剂及溶剂比。结果表明,N,N-二甲基甲酰胺(DMF)能够消除甲缩醛-甲醇共沸物系的共沸点;采用UNIQUAC模型对常压下甲缩醛-甲醇物系和加入溶剂N,N-二甲基甲酰胺的汽液平衡进行模拟,模拟结果和实验数据吻合较好。用间歇萃取精馏实验对甲缩醛粗品进行了分离,在实验条件下,可以从塔顶得到质量浓度为99.9%的高纯度甲缩醛产品。

  19. Production of ethanol from refinery waste gases. Phase 3. Engineering development. Annual report, April 1, 1995--May 15, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Arora, D.; Basu, R.; Phillips, J.R.; Wikstrom, C.V.; Clausen, E.C; Gaddy, J.L.

    1996-11-01

    Refineries discharge large volumes of H2, CO, and CO 2 from cracking, coking, and hydrotreating operations. This R&D program seeks to develop, demonstrate, and commercialize a biological process for converting these waste gases into ethanol for blending with gasoline. A 200,000 BPD refinery could produce up to 38 million gallons ethanol per year. The program is being conducted in 3 phases: II, technology development; III, engineering development; and IV, demonstration. Phase I, exploratory development, has been completed. The research effort has yielded two strains (Isolates O-52 and C-01) which are to be used in the pilot studies to produce ethanol from CO, CO2, and H2 in petroleum waste gas. Results from single continuous stirred tank reactor (CSTR) laboratory tests have shown that 20-25 g/L ethanol can be produced with < 5 g/L acetic acid byproduct. Laboratory studies with two CSTRs in series have yielded ethanol concentrations of 30-35 g/L with 2-4 g/L acetic acid byproduct. Water recycle from distillation back to the fermenter shows that filtration of the water before distillation eliminates the recycle of toxic materials back to the fermenter. Product recovery in the process will use direct distillation to the azeotrope, followed by adsorption to produce neat ethanol. This is less energy intensive than e.g. solvent extraction, azeotropic distillation, or pervaporation. Economic projections are quite attractive; the economics are refinery stream dependent and thus vary depending on refinery location and operation.

  20. Study of the hydrolysis of 3-aminopropyltriethoxysilane (KH550)and the surface modification of silica%KH550的水解工艺及其对SiO2表面改性的研究

    Institute of Scientific and Technical Information of China (English)

    高正楠; 江小波; 郭锴

    2012-01-01

    Through monitoring the change in conductivity during the hydrolysis of 3-aminopropyltriethoxysilane (KH550) and using FT-IR spectroscopy, the optimum conditions for the hydrolysis of KH550 were investigated. Wet silica gel from which, the physisorbed water was removed by azeotropic distillation or rapid solvent replacement was treated with KH550. The products were characterized by Fourier transform infrared spectroscopy (FT-IR) , di-n-butylphthalate (DBP) oil absorption, laser particle size analysis and contact angle measurements in order to investigate the effect of modification. The results showed that the contact angle of the modified silica increased, and the DBP absorption value significantly increased by more than 70% compared to the unmodified products. The pore volume was twice that of the unmodified silica. The amount of products in the organic phase also increased significantly. The azeotropic distillation method for wet gel modification afforded more hydrophobic silica than the solvent replacement method, and the contact angle between modified silica and water reached as high as 140°. The optimal conditions for silica modification involved a modifier mass fraction of 17. 5% of the weight of silica and the use of azeotropic distillation.%用电导率在线测量法和红外光谱法研究了硅烷偶联剂3-氨丙基三乙氧基硅烷( KH550)的水解工艺.采用共沸蒸馏和溶剂置换方式置换出湿凝胶中物理吸附水,并用KH550水解液对SiO2湿凝胶进行了改性.通过红外光谱( FT-IR)、邻苯二甲酸二丁酯(DBP)吸油值、粒度分析仪和接触角测定仪等方式对改性效果进行了表征.结果表明,采用KH550对SiO2湿凝胶进行改性后,产品的接触角显著提高,吸油值增大70%以上,孔容为未改性样品的2倍,有机相中的分散性显著提高.同时,对比共沸蒸馏和溶剂置换两种方式,共沸蒸馏得到疏水性更好的超细SiO2,改性后样品的接触角可以达到140°以

  1. SYNTHESIS OF METHYL METHACRYLATE FROM COAL-DERIVED SYNGAS

    Energy Technology Data Exchange (ETDEWEB)

    Makarand R. Gogate; James J. Spivey; Joseph R. Zoeller; Richard D. Colberg; Gerald N. Choi

    1999-07-19

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel collectively are developing a novel three-step process for the synthesis of methyl methacrylate (MMA) from coal-derived syngas that consists of the steps of synthesis of a propionate, its condensation with formaldehyde to form methacrylic acid (MAA), and esterification of MAA with methanol to produce MMA. The research team has completed the research on the three-step methanol-based route to MMA. Under an extension to the original contract, we are currently evaluating a new DME-based process for MMA. The key research need for DME route is to develop catalysts for DME partial oxidation reactions and DME condensation reactions. During the April-June quarter(04-06/99) the first in-situ formaldehyde generation from DME and condensation with methyl propionate is demonstrated and the results are summarized. The supported niobium catalyst shows better condensation activity, but supported tungsten catalyst has higher formaldehyde selectivity. The project team has also completed a 200-hour long term test of PA-HCHO condensation over 30% Nb{sub 2}O{sub 5}/SiO{sub 2}. Three activity cycles and two regeneration cycles were carried out. 30% Nb{sub 2}O{sub 5}/SiO{sub 2} showed similar MAA yields as 10% Nb{sub 2}O{sub 5}/SiO{sub 2} at 300 C. However, the deactivation appears to be slower with 30% Nb{sub 2}O{sub 5}/SiO{sub 2} than 10% Nb{sub 2}O{sub 5}/SiO{sub 2}. An detailed economic analysis of PA-HCHO condensation process for a 250 million lb/yr MMA plant is currently studied by Bechtel. Using the Amoco data-based azeotropic distillation model as the basis, an ASPEN flow sheet model was constructed to simulate the formaldehyde and propionic acid condensation processing section based on RTI's design data. The RTI MAA effluent azeotropic distillation column was found to be much more difficult to converge. The presence of non-condensible gases along with the byproduct DEK (both of which were not presented

  2. Features of non-congruent phase transition in modified Coulomb model of the binary ionic mixture

    CERN Document Server

    Stroev, N E

    2016-01-01

    Non-congruent gas-liquid phase transition (NCPT) have been studied in modified Coulomb model of a binary ionic mixture C(+6) + O(+8) on a \\textit{uniformly compressible} ideal electronic background /BIM($\\sim$)/. The features of NCPT in improved version of the BIM($\\sim$) model for the same mixture on background of \\textit{non-ideal} electronic Fermi-gas and comparison it with the previous calculations are the subject of present study. Analytical fits for Coulomb corrections to EoS of electronic and ionic subsystems were used in present calculations within the Gibbs--Guggenheim conditions of non-congruent phase equilibrium.Parameters of critical point-line (CPL) were calculated on the entire range of proportions of mixed ions $0azeotropic compositions was revealed in studied variants of BIM($\\sim$) in contrast to explicit e...

  3. GOBF-ARMA based model predictive control for an ideal reactive distillation column.

    Science.gov (United States)

    Seban, Lalu; Kirubakaran, V; Roy, B K; Radhakrishnan, T K

    2015-11-01

    This paper discusses the control of an ideal reactive distillation column (RDC) using model predictive control (MPC) based on a combination of deterministic generalized orthonormal basis filter (GOBF) and stochastic autoregressive moving average (ARMA) models. Reactive distillation (RD) integrates reaction and distillation in a single process resulting in process and energy integration promoting green chemistry principles. Improved selectivity of products, increased conversion, better utilization and control of reaction heat, scope for difficult separations and the avoidance of azeotropes are some of the advantages that reactive distillation offers over conventional technique of distillation column after reactor. The introduction of an in situ separation in the reaction zone leads to complex interactions between vapor-liquid equilibrium, mass transfer rates, diffusion and chemical kinetics. RD with its high order and nonlinear dynamics, and multiple steady states is a good candidate for testing and verification of new control schemes. Here a combination of GOBF-ARMA models is used to catch and represent the dynamics of the RDC. This GOBF-ARMA model is then used to design an MPC scheme for the control of product purity of RDC under different operating constraints and conditions. The performance of proposed modeling and control using GOBF-ARMA based MPC is simulated and analyzed. The proposed controller is found to perform satisfactorily for reference tracking and disturbance rejection in RDC.

  4. Thermodynamic study of (anthracene + phenanthrene) solid state mixtures.

    Science.gov (United States)

    Rice, James W; Fu, Jinxia; Sandström, Emma; Ditto, Jenna C; Suuberg, Eric M

    2015-11-01

    Polycyclic aromatic hydrocarbons (PAH) are common components of many materials, such as petroleum and various types of tars. They are generally present in mixtures, occurring both naturally and as byproducts of fuel processing operations. It is important to understand the thermodynamic properties of such mixtures in order to understand better and predict their behavior (i.e., fate and transport) in the environment and in industrial operations. To characterize better the thermodynamic behavior of PAH mixtures, the phase behavior of a binary (anthracene + phenanthrene) system was studied by differential scanning calorimetry, X-ray diffraction, and the Knudsen effusion technique. Mixtures of (anthracene + phenanthrene) exhibit non-ideal mixture behavior. They form a lower-melting, phenanthrene-rich phase with an initial melting temperature of 372 K (identical to the melting temperature of pure phenanthrene) and a vapor pressure of roughly lnP/Pa = -2.38. The phenanthrene-rich phase coexists with an anthracene-rich phase when the mole fraction of phenanthrene (xP) in the mixture is less than or equal to 0.80. Mixtures initially at xP = 0.90 consist entirely of the phenanthrene-rich phase and sublime at nearly constant vapor pressure and composition, consistent with azeotrope-like behavior. Quasi-azeotropy was also observed for very high-content anthracene mixtures (2.5 anthracene may accommodate very low levels of phenanthrene in its crystal structure.

  5. Synthesis and spectral characterization of ternary mixed-vanadyl β-diketonate complexes with Schiff bases.

    Science.gov (United States)

    Baranwal, Balram Prasad; Tripathi, Kiran; Singh, Alok Kumar; Tripathi, Saurabh

    2012-06-01

    A new method to synthesize some mononuclear ternary oxovanadium(IV) complexes of the general formula [VO(β-dike)(SB)] (where Hβ-dike=acetylacetone; benzoylacetone or dibenzoylmethane, HSB=Schiff bases) has been explored by stepwise substitutions of acetylacetonate ion of VO(acac)(2) with Schiff bases. The substituted acetylacetone could be fractionated out with p-xylene as an azeotrope. The complexes were characterized by elemental analyses, molecular weight determinations, spectral (electronic, infrared, (1)H NMR, EPR and powder XRD) studies, magnetic susceptibility measurements and cyclic voltammetry. Molar conductance measurements indicated the complexes to be non-electrolytes in nitrobenzene. Bidentate chelating nature of β-diketones and Schiff base anions in the complexes was established by infrared and NMR spectra. Molecular weight determinations confirmed mononuclear nature of the complexes. The EPR spectra illustrated coupling of the unpaired electron with (51)V nucleus (I=7/2). Cyclic voltammograms of all the complexes displayed two-step oxidation processes. The oxidation peak potential corresponded to the quasireversible one-electron oxidation process of the metal center, yielding V(V) species. Transmission electron microscopy (TEM) indicated spherical particles of ∼200 nm diameter. The synthesized complexes are mixed-ligand complexes showing a considerable hydrolytic stability in which vanadium is having coordination number 5. A square pyramidal geometry around vanadium has been assigned in all the complexes.

  6. Study on separation of a new diesel fuel additive polyoxymethylene dimethyl ethers%新型柴油添加剂聚缩醛二甲醚的分离研究

    Institute of Scientific and Technical Information of China (English)

    胡国庆; 田恒水; 魏永梅; 黄婕

    2015-01-01

    利用萃取等方法处理原料,有效地减轻了塔堵塞和共沸夹带过多的问题。采用常‐减压精馏相结合的方法对聚缩醛二甲醚进行了分离,得到了各产物分离的较佳工艺条件。实验中得到了纯度(质量分数)分别为99.06%的甲缩醛、97.81%的二聚产物、99.68%的三聚产物以及99.62%的四聚产物,为工业化分离提纯聚缩醛二甲醚提供了基础依据。%The raw material was treated by extraction ,which effectively reduced the tower plug‐ging and azeotropic entrainment .Polyoxymethylene dimethyl ethers (PODE) were separated by at‐mospheric‐vacuum rectification and the optimal technical conditions of each product separation were a‐chieved .In the experiment ,the purity of each product reached methyl 99 .06% ,PODE2 97 .81% , PODE3 99 .68% ,and PODE4 99 .62% ,w hich could provide an experimental basis for industrial puri‐fication of polyoxymethylene dimethyl ethers .

  7. Grafting of cellulose acetate with ionic liquids for biofuel purification by a membrane process: Influence of the cation.

    Science.gov (United States)

    Hassan Hassan Abdellatif, Faten; Babin, Jérôme; Arnal-Herault, Carole; David, Laurent; Jonquieres, Anne

    2016-08-20

    A new strategy was developed for grafting ionic liquids (ILs) onto cellulose acetate in order to avoid IL extraction and improve its performance for ethyl tert-butyl ether (ETBE) biofuel purification by the pervaporation membrane process. This work extended the scope of IL-containing membranes to the challenging separation of organic liquid mixtures, in which these ILs were soluble. The ILs contained the same bromide anion and different cations with increasing polar feature. The membrane properties were strongly improved by IL grafting. Their analysis in terms of structure-property relationships revealed the influence of the IL content, chemical structure and chemical physical parameters α, β, π* in the Kamlet-Taft polarity scale. The ammonium IL led to the best normalized flux of 0.182kg/m(2)h for a reference thickness of 5μm, a permeate ethanol content of 100% and an outstanding infinite separation factor for the azeotropic mixture EtOH/ETBE at 50°C.

  8. Discovery of optimal zeolites for challenging separations and chemical conversions through predictive materials modeling

    Science.gov (United States)

    Siepmann, J. Ilja; Bai, Peng; Tsapatsis, Michael; Knight, Chris; Deem, Michael W.

    2015-03-01

    Zeolites play numerous important roles in modern petroleum refineries and have the potential to advance the production of fuels and chemical feedstocks from renewable resources. The performance of a zeolite as separation medium and catalyst depends on its framework structure and the type or location of active sites. To date, 213 framework types have been synthesized and >330000 thermodynamically accessible zeolite structures have been predicted. Hence, identification of optimal zeolites for a given application from the large pool of candidate structures is attractive for accelerating the pace of materials discovery. Here we identify, through a large-scale, multi-step computational screening process, promising zeolite structures for two energy-related applications: the purification of ethanol beyond the ethanol/water azeotropic concentration in a single separation step from fermentation broths and the hydroisomerization of alkanes with 18-30 carbon atoms encountered in petroleum refining. These results demonstrate that predictive modeling and data-driven science can now be applied to solve some of the most challenging separation problems involving highly non-ideal mixtures and highly articulated compounds. Financial support from the Department of Energy Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences under Award DE-FG02-12ER16362 is gratefully acknowledged.

  9. Experimental and Numerical Study of the Radiant Induction-Unit and the Induction Radiant Air-Conditioning System

    Directory of Open Access Journals (Sweden)

    Qiang Si

    2016-12-01

    Full Text Available In this paper we proposed the novel air-conditioning system which combined induction ventilation and radiant air-conditioning. The indoor terminal device is the radiant induction-unit (RIDU. The RIDU is the induction unit combined with the pore radiant panel on which the copper pipes with rigid aluminum diffusion fins are installed. The two-stage evaporator chiller with the non-azeotropic mixture refrigerant is utilized in the system to reduce the initial investment in equipment. With the performance test and the steady state heat transfer model based on the theory of radiative heat transfer, the relationship between the induction ratio of the RIDU and the characteristic of the air supply was studied. Based on this, it is verified that the RIDU has a lower dew-point temperature and better anti-condensation performance than a traditional plate-type radiant panel. The characteristics of the radiation and convection heat transfer of the RIDU were studied. The total heat exchange of the RIDU can be 16.5% greater than that of the traditional plate-type radiant terminal.

  10. ARTI refrigerant database

    Energy Technology Data Exchange (ETDEWEB)

    Calm, J.M. [Calm (James M.), Great Falls, VA (United States)

    1998-08-01

    The Refrigerant Database is an information system on alternative refrigerants, associated lubricants, and their use in air conditioning and refrigeration. It consolidates and facilitates access to property, compatibility, environmental, safety, application and other information. It provides corresponding information on older refrigerants, to assist manufactures and those using alternative refrigerants, to make comparisons and determine differences. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern. The database provides bibliographic citations and abstracts for publications that may be useful in research and design of air-conditioning and refrigeration equipment. The complete documents are not included, though some may be added at a later date. The database identifies sources of specific information on many refrigerants including propane, ammonia, water, carbon dioxide, propylene, ethers, and others as well as azeotropic and zeotropic blends of these fluids. It addresses lubricants including alkylbenzene, polyalkylene glycol, polyolester, and other synthetics as well as mineral oils. It also references documents addressing compatibility of refrigerants and lubricants with metals, plastics, elastomers, motor insulation, and other materials used in refrigerant circuits. Incomplete citations or abstracts are provided for some documents. They are included to accelerate availability of the information and will be completed or replaced in future updates.

  11. Preparation of ZnO Nanoparticles and Photocatalytic H2 Production Activity from Different Sacrificial Reagent Solutions

    Institute of Scientific and Technical Information of China (English)

    Tian-you Peng; Hong-jin Lv; Peng Zeng; Xiao-hu Zhang

    2011-01-01

    ZnO nanoparticles were synthesized via a direct precipitation method followed by a heterogeneous azeotropic distillation and calcination processes,and then characterized by X-ray power diffraction,scanning electron microscopy,transmission electron microscopy,and nitrogen adsorption-desorption measurement.The effects of Pt-loading amount,calcination temperature,and sacrificial reagents on the photocatalytic H2 evolution efficiency from the present ZnO suspension were investigated.The experimental results indicate that ZnO nanoparticles calcined at 400 ℃ exhibit the best photoactivity for the H2 production in comparison with the samples calcined at 300 and 500 ℃,and the photocatalytic H2 production efficiency from a methanol solution is much higher than that from a triethanolamine solution.It can be ascribed to the oxidization of methanol also contributes to the H2 production during the photochemical reaction process.Moreover,the photocatalytic mechanism for the H2 production from the present ZnO suspension system containing methanol solution is also discussed in detail.

  12. Crosslinked chitosan/polyvinyl alcohol blend beads for removal and recovery of Cd(II) from wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Mahendra; Tripathi, Bijay P. [Electro-Membrane Processes Division, Central Salt and Marine Chemicals Research Institute, Council of Scientific and Industrial Research (CSIR), G.B. Marg, Bhavnagar 364002, Gujarat (India); Shahi, Vinod K., E-mail: vkshahi@csmcri.org [Electro-Membrane Processes Division, Central Salt and Marine Chemicals Research Institute, Council of Scientific and Industrial Research (CSIR), G.B. Marg, Bhavnagar 364002, Gujarat (India)

    2009-12-30

    Crosslinked chitosan/poly(vinyl alcohol) (PVA) beads were prepared by suspension of chitosan-PVA aqueous solution in a mixture of toluene and chlorobenzene. Some quantity of the water was distilled out as an azeotrope along with toluene-chlorobenzene and the droplets were chemically crosslinked by adding glutaraldehyde. The prepared crosslinked beads were characterized by FTIR, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The developed beads were used as an adsorbent for the adsorption of Cd(II) from wastewater. Effect of time, temperature, pH, adsorbent dose and adsorbate concentration on the adsorption of Cd(II) were investigated in batch process and pseudo-first and pseudo-second-order kinetic models were also evaluated. The equilibrium adsorption obeyed Langmuir and Freundlich isotherms as well as the thermodynamic parameters such as {Delta}G{sup o}, {Delta}H{sup o} and {Delta}S{sup o} were calculated. From thermodynamic data, it was found that the adsorption process was endothermic and spontaneous. The maximum adsorption of Cd(II) ions was found to be 73.75% at pH 6 and indicated that developed material could be effectively utilized for the removal of Cd(II) ions from wastewater.

  13. Pervaporation performance of PPO membranes in dehydration of highly hazardous mmh and udmh liquid propellants.

    Science.gov (United States)

    Moulik, Siddhartha; Kumar, K Praveen; Bohra, Subha; Sridhar, Sundergopal

    2015-05-15

    Polyphenylene oxide (PPO) membranes synthesized from 2,6-dimethyl phenol monomer were subjected to pervaporation-based dehydration of the highly hazardous and hypergolic monomethyl hydrazine (MMH) and unsymmetrical dimethyl hydrazine (UDMH) liquid propellants. Membranes were characterized by TGA, DSC and SEM to study the effect of temperature besides morphologies of surface and cross-section of the films, respectively. Molecular dynamics (MD) simulation was used to study the diffusion behavior of solutions within the membrane. CFD method was employed to solve the governing mass transfer equations by considering the flux coupling. The modeling results were highlighted by the experimental data and were in good agreement. High separation factors (35-70) and reasonable water fluxes (0.1-0.2 kg/m(2)h) were observed for separation of the aqueous azeotropes of MMH (35 wt%) and UDMH (20 wt%) and their further enrichment to >90% purity. Effect of feed composition, membrane thickness and permeate pressure on separation performance of PPO membranes were investigated to determine optimum operating conditions.

  14. Determination of impurities in crude light pyridine bases

    Energy Technology Data Exchange (ETDEWEB)

    Novikov, E.G.; Tsaur, A.G.; Lisina, L.A.; Dybkin, P.A.

    1981-01-01

    Hydrogen cyanide, hydrogen sulfide, ammonia and phenols are always products of coal pyrolysis. In addition the coke oven gas contains carbon disulfide. The simultaneous presence of ammonia and carbon disulfide leads inevitably to the formation of thiocyanates in the entire recovery system before the saturator, and particularly in the ammonia liquor. All these compounds may be expected to be present in the crude light pyridine bases (CLPB). This causes corrosion of the equipment and reduces the photostability of the final process products. The ability of the phenols to form high boiling point azeotropes with the bases reduces the ..beta..-picoline fraction yield. For these reasons the presence of the stated impurities in the CLPB is undesirable. In the present work an estimate has been made of the average annual concentration of phenols, cyanides, thiocyanates and chlorides in the crude light pyridine bases of all the plants supplying this material in the Eastern USSR. The table shows only the mean values of the concentrations for each component in the samples of the individual plants, and also those for water.

  15. Extractive distillation of nitric acid using the two-pot concept

    Energy Technology Data Exchange (ETDEWEB)

    Counce, R.M.; Groenier, W.S.; Holland, W.D.; Jubin, R.T.; North, E.D.; Thompson, L.E. Jr.; Hebble, T.L.

    1982-12-01

    Experiments have confirmed the validity of a novel design for a nitric acid concentration system for use in shielded nuclear fuel reprocessing plants. Current plans for producing the scrub solution for the IODOX process require the concentration and recycle of low strength (< 68.5 wt %) nitric acid sources. The described system utilizes extractive distillation with Mg(NO/sub 3/)/sub 2/ as the solvent and features two pots: an extractive distillation pot in which a concentrated acid product is obtained by contacting the acid feed with the solvent and a solvent recovery pot in which the solvent is dehydrated and recovered for recycle. In these experiments, a concentrated product of 89 wt % nitric acid was produced from azeotropic feed. The available vapor-liquid equilibria data for the Mg(NO/sub 3/)/sub 2/-HNO/sub 3/-H/sub 2/O system has been empirically correlated, and a design methodology has been developed for the two-pot extractive distillation process.

  16. Thermodynamic study of (anthracene + phenanthrene) solid state mixtures

    Science.gov (United States)

    Rice, James W.; Fu, Jinxia; Sandström, Emma; Ditto, Jenna C.; Suuberg, Eric M.

    2015-01-01

    Polycyclic aromatic hydrocarbons (PAH) are common components of many materials, such as petroleum and various types of tars. They are generally present in mixtures, occurring both naturally and as byproducts of fuel processing operations. It is important to understand the thermodynamic properties of such mixtures in order to understand better and predict their behavior (i.e., fate and transport) in the environment and in industrial operations. To characterize better the thermodynamic behavior of PAH mixtures, the phase behavior of a binary (anthracene + phenanthrene) system was studied by differential scanning calorimetry, X-ray diffraction, and the Knudsen effusion technique. Mixtures of (anthracene + phenanthrene) exhibit non-ideal mixture behavior. They form a lower-melting, phenanthrene-rich phase with an initial melting temperature of 372 K (identical to the melting temperature of pure phenanthrene) and a vapor pressure of roughly lnP/Pa = −2.38. The phenanthrene-rich phase coexists with an anthracene-rich phase when the mole fraction of phenanthrene (xP) in the mixture is less than or equal to 0.80. Mixtures initially at xP = 0.90 consist entirely of the phenanthrene-rich phase and sublime at nearly constant vapor pressure and composition, consistent with azeotrope-like behavior. Quasi-azeotropy was also observed for very high-content anthracene mixtures (2.5 < xP < 5) indicating that anthracene may accommodate very low levels of phenanthrene in its crystal structure. PMID:26973354

  17. Acetone-Butanol-Ethanol (ABE) production in fermentation of enzymatically hydrolyzed cassava flour by Clostridium beijerinckii BA101 and solvent separation.

    Science.gov (United States)

    Lépiz-Aguilar, Leonardo; Rodríguez-Rodríguez, Carlos E; Arias, María Laura; Lutz, Giselle

    2013-08-01

    Cassava constitutes an abundant substrate in tropical regions. The production of butanol in ABE fermentation by Clostridium beijerinckii BA101 using cassava flour (CF) was scaled-up to bioreactor level (5 L). Optimized fermentation conditions were applied; that is, 40℃, 60 g/l CF, and enzymatic pretreatment of the substrate. The batch fermentation profile presented an acidogenic phase for the first 24 h and a solventogenic phase afterwards. An average of 37.01 g/l ABE was produced after 83 h, with a productivity of 0.446 g/l/h. Butanol production was 25.71 g/l with a productivity of 0.310 g/l/h, high or similar to analogous batch processes described for other substrates. Solvent separation by different combinations of fractioned and azeotropic distillation and liquid-liquid separation were assessed to evaluate energetic and economic costs in downstream processing. Results suggest that the use of cassava as a substrate in ABE fermentation could be a cost-effective way of producing butanol in tropical regions.

  18. Separation of the Mixed Solvent Including Methanol,Acetone and Ethyl acetate in Cefotaxime sodium Production%头孢噻肟钠生产中甲醇、丙酮与乙酸乙酯混合溶媒的分离

    Institute of Scientific and Technical Information of China (English)

    王亚其; 李科

    2012-01-01

    通过萃取精馏、精馏对甲醇、丙酮与乙酸乙酯的混合溶媒加以分离,通过对生产数据的调整,确定了萃取精馏过程中混合溶媒与萃取水加入比例为1∶1,此条件下,萃取效果最好。萃取塔顶可以得到丙酮与乙酸乙酯和水的共沸物,塔底可以得到纯度为99.5%的甲醇。%To separate the mixture solvent including methanol,acetone and ethyl acetate by extractive distillation and distillation.Through adjusting production data,to determine the ratio of the mixture solvent to water was 1∶1 in the the extractive distillation process,and under the conditions,the extraction results were the best.To obtain the azeotrope including acetone ethyl acetate and water in the top of the tower,99.5% methanol in the bottom.

  19. 水热法制备片状氧化铝纳米粉体%Preparation of Plate-Like Alumina Nanometer Powder by Hydrothermal Method

    Institute of Scientific and Technical Information of China (English)

    马小玲

    2012-01-01

    在碳酸氢铵和PEG2000混合溶液中,加入硫酸铝铵和PEG400的混合溶液得到白色沉淀,将白色沉淀物与正丁醇共沸后,在900℃煅烧1 h,得到γ-Al2O3粉体,粉体粒径约为20 nm;在1 200 ℃煅烧1h,得到片状α-Al2O3粉体,粉体粒径约为60 nm.%When the solution with aluminium ammonium sulfate and PEG400 was mixed with the solution content of ammonium hydrogen carbonate and PEG2000,the white precipitation was obtained. Then the precipitation was azeotropic distillation. The y- A12O3 powder was obtained at 900 C for 1 h.with size about 20 nm. The plate-like a-- AI2O3 powder was obtained at 1 200 "C for 1 h.with size about 60 nm.

  20. 水热法制备片状氧化铝纳米粉体%Preparation of Plate-Like Alumina Nanometer Powder by Hydrothermal Method

    Institute of Scientific and Technical Information of China (English)

    马小玲

    2013-01-01

    When the solution with aluminium ammonium sulfate and PEG400 was mixed with the solution content of ammonium hydro-gen carbonate and PEG2000 ,the white precipitation was obtained .Then the precipitation was azeotropic distillation .The γ -Al2 O3 powder was obtained at 900 ℃ for 1 h ,with size about 20 nm .The plate-likeα-Al2 O3 powder was obtained at 1 200 ℃ for 1 h ,with size about 60 nm .%在碳酸氢铵和PEG2000混合溶液中,加入硫酸铝铵和PEG400的混合溶液得到白色沉淀,将白色沉淀物与正丁醇共沸后,在900℃煅烧1 h ,得到γ-Al2 O3粉体,粉体粒径约为20 nm ;在1200℃煅烧1 h ,得到片状α-Al2 O3粉体,粉体粒径约为60 nm。

  1. Synthesis, characterization, and application of silica supported ionic liquid as catalyst for reductive amination of cyclohexanone with formic acid and triethyl amine as hydrogen source

    Institute of Scientific and Technical Information of China (English)

    Ashif H. Tamboli; Avinash A. Chaugule; Faheem A. Sheikh; Wook-Jin Chung; Hern Kim

    2015-01-01

    A silica supported ionic liquid was synthesized and characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, X-ray diffraction, N2 adsorption-desorption, and thermogravimetric analysis. All these techniques, especially SEM results indicated the presence of well-defined spherical particles having diameters larger than the pristine silica particles, confirming the successful immobilization of the ionic liquid. The prepared silica supported ionic liquid was used in the reductive amination of cyclohexanone under different conditions with different azeo-tropic mixtures of formic acid and triethyl amine as a hydrogen source. The catalyst showed effi-cient catalytic performance and excellent yields of N-cyclohexyl amine derivatives in the range of 58%to 84%at 30 °C. After completion of the reaction, the catalyst was easily recovered by simple filtration and reused for another five cycles without any significant impact on product yields. The obtained catalytic performance indicates that the present catalyst is green, very active, and reusable for the reductive amination of cyclohexanone.

  2. Electrochemical characterization of YSZ thick films deposited by dip-coating process

    Energy Technology Data Exchange (ETDEWEB)

    Mauvy, F.; Lalanne, C.; Bassat, J.M.; Grenier, J.C. [Institut de Chimie de la Matiere Condensee de Bordeaux ICMCB - CNRS, Universite Bordeaux 1, 87, av. du Dr. A. Schweitzer, 33 608 Pessac-Cedex (France); Lenormand, P.; Ansart, F. [Centre Interuniversitaire de Recherche et d' Ingenierie et d' Ingenierie des Materiaux, CIRIMAT, Universite Paul Sabatier, Bat. 2R1, 118 route de Narbonne, 31062 Toulouse Cedex (France)

    2007-09-27

    Yttria stabilized zirconia (YSZ, 8% Y{sub 2}O{sub 3}) thick films were coated on dense alumina substrates by a dip-coating process. The suspension was obtained by addition of a polymeric matrix in a stable suspension of commercial YSZ (Tosoh) powders dispersed in an azeotropic mixture MEK-EtOH. The suspension composition was improved by the addition of YSZ Tosoh particles encapsulated by zirconium alkoxide sol containing yttrium nitrate which are the precursors of the 8-YSZ oxide. This optimal formulation allowed preparing, via a dip-coating process, thick films which were, after thermal treatment, homogeneous, dense and crack-free. A specific method was performed to measure the electrical conductivity, i.e. to determine the ionic conductivity of the film: it uses the four-point probe technique combined with ac impedance spectroscopy. The good agreement between the classical two-electrode measurements performed on YSZ pellets and the four-electrode ones performed on YSZ films allows concluding that this method is relevant for characterizing the transport properties of thick films. (author)

  3. ARTI Refrigerant Database

    Energy Technology Data Exchange (ETDEWEB)

    Cain, J.M. [Calm (James M.), Great Falls, VA (United States)

    1993-04-30

    The Refrigerant Database consolidates and facilitates access to information to assist industry in developing equipment using alternative refrigerants. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern. The database provides bibliographic citations and abstracts for publications that may be useful in research and design of air-conditioning and refrigeration equipment. The complete documents are not included. The database identifies sources of specific information on R-32, R-123, R-124, R-125, R-134, R-134a, R-141b, R-142b, R-143a, R-152a, R-245ca, R-290 (propane), R-717 (ammonia), ethers, and others as well as azeotropic and zeotropic blends of these fluids. It addresses lubricants including alkylbenzene, polyalkylene glycol, ester, and other synthetics as well as mineral oils. It also references documents addressing compatibility of refrigerants and lubricants with metals, plastics, elastomers, motor insulation, and other materials used in refrigerant circuits. Incomplete citations or abstracts are provided for some documents to accelerate availability of the information and will be completed or replaced in future updates.

  4. ARTI Refrigerant Database. [Quarterly progress report, 1 July 1993--30 September 1993

    Energy Technology Data Exchange (ETDEWEB)

    Calm, J.M.

    1993-11-28

    The Refrigerant Database consolidates and facilitates access to information to assist industry in developing equipment using alternative refrigerants. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern. The database provides bibliographic citations and abstracts for publications that may be useful in research and design of air-conditioning and refrigeration equipment. The complete documents are not included, though some may be added at a later date. The database identifies sources of specific information on R-32, R-123, R-124, R-125, R-134, R134a, R-141b, R-142b, R-143a, R-152a, R-227ea, R-245ca, R-290 (propane), R-717 (ammonia), ethers, and others as well as azeotropic and zeotropic blends of these fluids. It addresses lubricants including alkylbenzene, polyalkylene glycol, polyol ester, and other synthetics as well as mineral oils. It also references documents addressing compatibility of refrigerants and lubricants with metals, plastics, elastomers, motor insulation, and other materials used in refrigerant circuits. Incomplete citations or abstracts are provided for some documents. They are included to accelerate availability of the information and will be completed or replaced in future updates.

  5. Al2O3-2SiO2 Nanoparticles with Defined AI-Si Ratio: Processing Optimization and Conversion

    Institute of Scientific and Technical Information of China (English)

    郑广俭; 崔学民; 张伟鹏; 童张法; 李峰

    2012-01-01

    Attempts had been made to synthesize Al2O3-2SiO2 nanopowders by sol-gel method with tetraethoxysilane(TEOS) and aluminum nitrate(ANN) as the starting materials.DTS,TEM,SEM and BET were employed to study the effects of process parameters on the size,specific surface area and structure(morphology) of powders.The alkali-activation reactivity of the powders was tested for manufacturing geopolymers and their hydrothermal reactions were performed for fabricating zeolites.The results show that the optimum process parameters and drying method for preparing Al2O3-2SiO2 nanopowders are as follows:the molar ratio of water and ethanol to TEOS are 0:1 and 12:1 respectively at synthetic temperature of 50 ℃ and the drying method is azeotropic distillation with microwave drying.The average particle diameters of the powders were about 70 nm and the largest BET specific surface area was up to 669 m^2·g^-1.The compressive strength of the geopolymer and the calcium exchange capacity(by CaCO3) of NaA zeolite prepared with the powders reached to 29 MPa and 366 m^2·g^-1 respectively.

  6. MESERAN Test Results for Elimination of Flammable Solvents in Wipe Applications at Pantex

    Energy Technology Data Exchange (ETDEWEB)

    M. G. Benkovich

    2005-03-30

    In recent years, efforts have been made within the nuclear weapons complex (National Nuclear Security Administration) of the Department of Energy (DOE) to replace Resource Conservation and Recovery Act (RCRA) regulated solvents (i.e., flammable, toxic, corrosive, and reactive) and ozone-depleting chemicals (ODC) with more benign alternatives. Within the National Nuclear Security Administration (NNSA) and the Department of Defense (DoD) sectors, these solvents are used for cleaning hardware during routine maintenance operations. A primary goal of this study is to replace flammable solvents for wiping applications. Two cleaners, including a hydrofluoroether (HFE) and an azeotrope of the HFE and isopropyl alcohol (IPA), have been studied as potential replacements for flammable solvents. Cleaning efficacy, short-term and longterm materials compatibility, corrosion, drying times, flammability, environment, safety and health (ES&H) issues and accelerated aging studies are among the tests that are being conducted and that are used to screen candidate solvents by the interagency team performing this work. The results are compared to the traditionally used isopropyl alcohol, which serves as the baseline cleaner. This report details the results of MESERAN (Measurement and Evaluation of Surfaces by Evaporative Rate ANalysis) testing performed at the Kansas City Plant (KCP) to quantify the cleaning efficacy on samples contaminated with the various contaminants and cleaned by wiping with the various solvents being evaluated.

  7. Fluorocarbon adsorption in hierarchical porous frameworks

    Science.gov (United States)

    Motkuri, Radha Kishan; Annapureddy, Harsha V. R.; Vijaykumar, M.; Schaef, H. Todd; Martin, Paul F.; McGrail, B. Peter; Dang, Liem X.; Krishna, Rajamani; Thallapally, Praveen K.

    2014-07-01

    Metal-organic frameworks comprise an important class of solid-state materials and have potential for many emerging applications such as energy storage, separation, catalysis and bio-medical. Here we report the adsorption behaviour of a series of fluorocarbon derivatives on a set of microporous and hierarchical mesoporous frameworks. The microporous frameworks show a saturation uptake capacity for dichlorodifluoromethane of >4 mmol g-1 at a very low relative saturation pressure (P/Po) of 0.02. In contrast, the mesoporous framework shows an exceptionally high uptake capacity reaching >14 mmol g-1 at P/Po of 0.4. Adsorption affinity in terms of mass loading and isosteric heats of adsorption is found to generally correlate with the polarizability and boiling point of the refrigerant, with dichlorodifluoromethane >chlorodifluoromethane >chlorotrifluoromethane >tetrafluoromethane >methane. These results suggest the possibility of exploiting these sorbents for separation of azeotropic mixtures of fluorocarbons and use in eco-friendly fluorocarbon-based adsorption cooling.

  8. Coupled Pervaporation-Reaction Distillation Process for the Production of n-Bromopropane

    Institute of Scientific and Technical Information of China (English)

    毛澄宇; 余立新; 郭庆丰; 席春光

    2002-01-01

    The reaction of n-C3H7OH+HBr=n-C3H7Br+H2O was used to experimentally study a coupled pervaporation (PV)-reaction distillation (RD) process. The results show that polyvinyl alcohol (PVA) is a suitable membrane material for water removal. The typical separation properties of PVA polyacrylonitrile (PAN) composite membranes are a highest flux of 780 g/(m2*h) and a separation factor of 840 for the C3H7OH concentration in the original feed of 95% at 90℃ and below 3300 Pa(abs). Reaction distillation produced the n-bromopropane from the distillation column as a ternary azeotropic liquid mixture of C3H7OH, H2O and C3H7Br, with a product concentration of about 92%. The coupled PV-RD membrane reactor experiment shows that the BrPr yield can reach 92%, much higher than that for reaction-distillation without pervaporation.

  9. Pervaporation applied for dewatering of reaction mixture during esterification

    Directory of Open Access Journals (Sweden)

    Krasiński Andrzej

    2016-03-01

    Full Text Available In this work the esterification of diethyl tartrate was studied. The research was focused on the enhancement of reversible reaction yield, which is accomplished by dewatering of the reaction mixture. The removal of water shifts the equilibrium towards the main product. Pervaporation was applied for this purpose, and results were compared to distillation. The advantages and limitations of both processes are discussed. The experimental part consists of dewatering of mixture after the reaction had reached the equilibrium, and was subsequently fed to the test rig equipped with a single zeolite membrane purchased from Pervatech B.V. Results show a significant conversion increase as a result of water removal by pervaporation. Compared to distillation no addition of organics is necessary to efficiently remove water above the azeotrope. Nevertheless, some limitations and issues which call for optimisation are pointed out. A simple numerical model is proposed to support design and sizing of the pervaporation system. Various modes of integrated system operation are also briefly discussed.

  10. Pollution Prevention Wipe Application Study

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, E.P.; Modderman, W.E.; Montoya, M.G.

    1999-02-10

    As part of a pollution prevention program, a study was conducted at Sandia National Laboratories and at the Amarillo, ''Pantex Plant'' to identify a suitable replacement solvent(s) for cleaning hardware during routine maintenance operations. Current cleaning is performed using solvents (e.g. acetone, toluene, MEK, alcohols) that are classified as Resource Conservation and Recovery Act (RCW) materials. The Environmental Protection Agency (EPA) has assigned four characteristics as the criteria for determining whether a material is identified as hazardous under RCRA: Ignitability, Corrosivity, Reactivity and Toxicity. Within the DOE and DoD sector, these solvents are used with hand wipes to clean surfaces prior to O-ring replacement, to remove decals for new labeling, to clean painted surfaces prior to reconditioning, and for other general maintenance purposes. In some cases, low level radioactive contamination during cleaning necessitates that the RCIL4 solvent-containing wipes be classified as mixed waste. To avoid using RCRA materials, cleaning candidates were sought that had a flashpoint greater than 140 F, a pH between 2.5 and 12.5, and did not fail the reactivity and toxicity criteria. Three brominated cleaners, two hydrofluoroether azeotropes and two aliphatic hydrocarbon cleaner formulations were studied as potential replacements. Cleaning efficacy, materials compatibility, corrosion and accelerated aging studies were conducted and used to screen potential candidates. Hypersolve NPB (an n-propyl bromide based formulation) consistently ranked high in removing typical contaminants for weapons applications.

  11. Combustion water purification techniques influence on OBT analysing using liquid scintillation counting method

    Energy Technology Data Exchange (ETDEWEB)

    Varlam, C.; Vagner, I.; Faurescu, I.; Faurescu, D. [National Institute for Cryogenics and Isotopic Technologies, Valcea (Romania)

    2015-03-15

    In order to determine organically bound tritium (OBT) from environmental samples, these must be converted into water, measurable by liquid scintillation counting (LSC). For this purpose we conducted some experiments to determine OBT level of a grass sample collected from an uncontaminated area. The studied grass sample was combusted in a Parr bomb. However usual interfering phenomena were identified: color or chemical quench, chemiluminescence, overlap over tritium spectrum because of other radionuclides presence as impurities ({sup 14}C from organically compounds, {sup 36}Cl as chloride and free chlorine, {sup 40}K as potassium cations) and emulsion separation. So the purification of the combustion water before scintillation counting appeared to be essential. 5 purification methods were tested: distillation with chemical treatment (Na{sub 2}O{sub 2} and KMnO{sub 4}), lyophilization, chemical treatment (Na{sub 2}O{sub 2} and KMnO{sub 4}) followed by lyophilization, azeotropic distillation with toluene and treatment with a volcanic tuff followed by lyophilization. After the purification step each sample was measured and the OBT measured concentration, together with physico-chemical analysis of the water analyzed, revealed that the most efficient method applied for purification of the combustion water was the method using chemical treatment followed by lyophilization.

  12. Electrochemical characterization of YSZ thick films deposited by dip-coating process

    Science.gov (United States)

    Mauvy, F.; Lenormand, P.; Lalanne, C.; Ansart, F.; Bassat, J. M.; Grenier, J. C.; Groupement de Recherches Cnrs "Pacte", Gdr 2985

    Yttria stabilized zirconia (YSZ, 8% Y 2O 3) thick films were coated on dense alumina substrates by a dip-coating process. The suspension was obtained by addition of a polymeric matrix in a stable suspension of commercial YSZ (Tosoh) powders dispersed in an azeotropic mixture MEK-EtOH. The suspension composition was improved by the addition of YSZ Tosoh particles encapsulated by zirconium alkoxide sol containing yttrium nitrate which are the precursors of the 8-YSZ oxide. This optimal formulation allowed preparing, via a dip-coating process, thick films which were, after thermal treatment, homogeneous, dense and crack-free. A specific method was performed to measure the electrical conductivity, i.e. to determine the ionic conductivity of the film: it uses the four-point probe technique combined with ac impedance spectroscopy. The good agreement between the classical two-electrode measurements performed on YSZ pellets and the four-electrode ones performed on YSZ films allows concluding that this method is relevant for characterizing the transport properties of thick films.

  13. Transferable potentials for phase equilibria-united atom description of five- and six-membered cyclic alkanes and ethers.

    Science.gov (United States)

    Keasler, Samuel J; Charan, Sophia M; Wick, Collin D; Economou, Ioannis G; Siepmann, J Ilja

    2012-09-13

    While the transferable potentials for phase equilibria-united atom (TraPPE-UA) force field has generally been successful at providing parameters that are highly transferable between different molecules, the polarity and polarizability of a given functional group can be significantly perturbed in small cyclic structures, which limits the transferability of parameters obtained for linear molecules. This has motivated us to develop a version of the TraPPE-UA force field specifically for five- and six-membered cyclic alkanes and ethers. The Lennard-Jones parameters for the methylene group obtained from cyclic alkanes are transferred to the ethers for each ring size, and those for the oxygen atom are common to all compounds for a given ring size. However, the partial charges are molecule specific and parametrized using liquid-phase dielectric constants. This model yields accurate saturated liquid densities and vapor pressures, critical temperatures and densities, normal boiling points, heat capacities, and isothermal compressibilities for the following molecules: cyclopentane, tetrahydrofuran, 1,3-dioxolane, cyclohexane, oxane, 1,4-dioxane, 1,3-dioxane, and 1,3,5-trioxane. The azeotropic behavior and separation factor for the binary mixtures of 1,3-dioxolane/cyclohexane and ethanol/1,4-dioxane are qualitively reproduced.

  14. The Role of Hydrogen Bonding on Laminar Burning Velocity of Hydrous and Anhydrous Ethanol Fuel with Small Addition of n-Heptane

    Directory of Open Access Journals (Sweden)

    I Made Suarta

    2016-01-01

    Full Text Available The molecular structure of mixed hydrous and anhydrous ethanol with up to 10% v n-heptane had been studied. The burning velocity was examined in a cylindrical explosion combustion chamber. The result showed that the burning velocity of hydrous ethanol is higher than anhydrous ethanol and n-heptane at stoichiometric, rich, and very rich mixtures. The burning velocity of hydrous ethanol with n-heptane drops drastically compared to the burning velocity of anhydrous ethanol with n-heptane. It is caused by two reasons. Firstly, there was a composition change of azeotropic hydrous ethanol molecules within the mixture of fuel. Secondly, at the same volume the number of ethanol molecules in hydrous ethanol was less than in anhydrous ethanol at the same composition of the n-heptane in the mixture. At the mixture of anhydrous ethanol with n-heptane, the burning velocity decreases proportionally to the addition of the n-heptane composition. The burning velocity is between the velocities of anhydrous ethanol and n-heptane. It shows that the burning velocity of anhydrous ethanol mixed with n-heptane is only influenced by the mixture composition.

  15. 含离子液体溴化1-丙基-3-甲基咪唑的二元和三元体系的蒸气压测定%Determination of Vapor Pressures for Binary and Ternary Mixtures Containing Ionic Liquid 1-propyl-3-methylimidazolium Bromide

    Institute of Scientific and Technical Information of China (English)

    Zakariya R.Abusen; 赵瑾; 李春喜; 王子镐

    2005-01-01

    Vapor pressure values of binary systems water + ethanol, water + ionic liquid 1-propyl-3-methylimidazolium bromide ([PMIM] [Br]), ethanol + [PMIM][Br] and ternary system water + ethanol + [PMIM] [Br]at different temperatures were measured by using a modified boiling point method in various concentrations of (16.66%, 33.7%), (17.4%, 33.9%) and (16.5%, 32%) mass percent of ionic liquid, respectively. The experimental vapor pressures of solvent were well correlated by the Antoine-type equation, and the overall average absolute deviation (AAD) was found to be 0.39%. The experimental results for mixtures containing ionic liquid indicate that the vapor pressure of the solvents can be decreased noticeably to different extent due to the affinity difference between ionic liquid and solvent, which is similar to the salt effect of common inorganic salts. As a result, ionic liquid may find industrial applications in extractive distillations for the system with a low separation factor or even for an azeotropic mixture.

  16. Retrofit of an MTBE-unit to ETBE

    Energy Technology Data Exchange (ETDEWEB)

    Rix, A.; Peters, U. [Degussa GmbH, Marl (Germany)

    2007-07-01

    New European policies on renewable fuels have created substantial market pressure to increase the share of bio-fuels. For blending in gasoline, ETBE formed by etherification of isobutene with bio-ethanol is an interesting alternative to direct blending of bio-ethanol. Since the physical properties of methanol and ethanol - and consequently MTBE and ETBE - are quite similar, MTBE-plants can be retrofitted for ETBE-production. Experience from a retrofit-project at Marl is presented. In an integrated C4-plant, isobutene removal is one the most important tasks of the etherification unit to purify the raffinate 2 stream for butene-1 production. Compared to MTBE, reaction rate and equilibrium constant are lower and suitable means of maintaining isobutene conversion on former levels must be found. Furthermore, the extraction of excess alcohol and its recovery by distillation is more difficult. The ethanol-water azeotrope formed on top of the alcohol recovery column has to undergo a further drying process. Alternatives for ethanol drying have been evaluated and performance data for a membrane process is presented. (orig.)

  17. Shortcut Algorithm for Simulation of Batch Extractive Distillation

    Institute of Scientific and Technical Information of China (English)

    WU Huixiong; XU Shimin; HU Hui; XIAO Bin

    2007-01-01

    The batch extractive distillation (BED) process has the advantages of both batch and extractive distillation. It is one of the most promising means for the separation of azeotropic and close-boiling point systems. However, so far this process has not been applied in industry due to its over-complexity. A new shortcut model was proposed to simulate the operation of the batch extractive distillation operations. This algorithm is based on the assumption that the batch extractive distillation column can be considered as a continuous extractive distillation column with changing feed at anytime. Namely, the whole batch process is simulated as a succession of a finite number of steady states of short duration, in which holdup is considered as constant mole. For each period of time the batch extractive distillation process is solved through the algorithm for continuous extractive distillation. Finally, the practical implementation of the shortcut model is discussed and data from the lab-oratory and literature are presented. It is found that this model has better adaptability, more satisfactory accuracy and less calculative load than previous rigorous model. Hence the algorithm for simulating BED is verified.

  18. Separation of Benzene and Cyclohexane by Batch Extractive Distillation

    Institute of Scientific and Technical Information of China (English)

    XU Jiao; ZHANG Weijiang; GUI Xia

    2007-01-01

    Azeotropic liquid mixture cannot be separated by conventional distillation. But extractive distillation or combination of the two can be valid for them. An experiment to separate benzene and cyclohexane by batch extractive distillation was carried out with N, N-dimethylformide (DMF), dimethyl sulfoxide (DMSO) and their mixture as extractive solvent. The effect of the operation parameterssuch as solvent flow rate and reflux ratio on the separation was studied under the same operating conditions. The results show that the separation effect was improved with the increase of solvent flow rate and the reflux ratio; all the three extractive solvents can separate benzene and cyclohexane, with DMF being the most efficient one, the mixture the second, and DMSO the least. In the experiment the best operation conditions are with DMF as extractive solvent, the solvent flow rate being 12.33 mL/min, and the reflux ratio being 6. As a result, we can get cyclohexane from the top of tower with the average product content being 86.98%, and its recovering ratio being 83.10%.

  19. 乙醇-乙酸乙酯体系的间歇萃取精馏研究%Study on Batch Extractive Distillation of Ethanol- Ethyl Acetate System

    Institute of Scientific and Technical Information of China (English)

    张剑锋; 袁旭宏; 黄海明; 陈红; 叶余原; 尤玉静; 熊双喜

    2014-01-01

    In the conventional batch extractive distillation experimental device, the batch extractive distillation process of ethanol- ethyl acetate system by using N,N-dimethy formamide and dimethy sulphoxide as extracting agents was studied. Effects of total reflux time, extractant, azeotrope composition, volume ratio of solvent to mixture ,adding salt, adding alkali and other factors on the extractive distillation separation of ethanol- ethyl acetate system were investigated, then the best extractive distillation conditions were obtained .%在常规的间歇萃取精馏实验装置中,研究了以 N,N-二甲基酰胺(DMF)和二甲亚砜(DMSO)作萃取剂;在间歇萃取精馏塔中分离乙醇-乙酸乙酯体系的过程。对全回流时间、不同萃取剂、恒沸物组成、溶剂和混合物的体积比、加盐及加碱等因素考察,分析萃取精馏分离乙醇-乙酸乙酯共沸体系的影响,从而得出最佳的萃取条件。

  20. Concerted nucleophilic aromatic substitution with 19F- and 18F-

    Science.gov (United States)

    Neumann, Constanze N.; Hooker, Jacob M.; Ritter, Tobias

    2016-06-01

    Nucleophilic aromatic substitution (SNAr) is widely used by organic chemists to functionalize aromatic molecules, and it is the most commonly used method to generate arenes that contain 18F for use in positron-emission tomography (PET) imaging. A wide range of nucleophiles exhibit SNAr reactivity, and the operational simplicity of the reaction means that the transformation can be conducted reliably and on large scales. During SNAr, attack of a nucleophile at a carbon atom bearing a ‘leaving group’ leads to a negatively charged intermediate called a Meisenheimer complex. Only arenes with electron-withdrawing substituents can sufficiently stabilize the resulting build-up of negative charge during Meisenheimer complex formation, limiting the scope of SNAr reactions: the most common SNAr substrates contain strong π-acceptors in the ortho and/or para position(s). Here we present an unusual concerted nucleophilic aromatic substitution reaction (CSNAr) that is not limited to electron-poor arenes, because it does not proceed via a Meisenheimer intermediate. We show a phenol deoxyfluorination reaction for which CSNAr is favoured over a stepwise displacement. Mechanistic insights enabled us to develop a functional-group-tolerant 18F-deoxyfluorination reaction of phenols, which can be used to synthesize 18F-PET probes. Selective 18F introduction, without the need for the common, but cumbersome, azeotropic drying of 18F, can now be accomplished from phenols as starting materials, and provides access to 18F-labelled compounds not accessible through conventional chemistry.

  1. New phase diagrams for dense carbon-oxygen mixtures and white dwarf evolution

    CERN Document Server

    Althaus, Leandro G; Isern, Jordi; Córsico, Alejandro H; Bertolami, Marcelo M Miller

    2011-01-01

    Cool white dwarfs are reliable and independent stellar chronometers. The most common white dwarfs have carbon-oxygen dense cores. Consequently, the cooling ages of very cool white dwarfs sensitively depend on the adopted phase diagram of the carbon-oxygen binary mixture. A new phase diagram of dense carbon-oxygen mixtures appropriate for white dwarf interiors has been recently obtained using direct molecular dynamics simulations. In this paper, we explore the consequences of this phase diagram in the evolution of cool white dwarfs. To do this we employ a detailed stellar evolutionary code and accurate initial white dwarf configurations, derived from the full evolution of progenitor stars. We use two different phase diagrams, that of Horowitz et al. (2010), which presents an azeotrope, and the phase diagram of Segretain & Chabrier (1993), which is of the spindle form. We computed the evolution of 0.593 and 0.878M_sun white dwarf models during the crystallization phase, and we found that the energy released...

  2. Process for dehydration of oregano using propane gas as fuel

    Directory of Open Access Journals (Sweden)

    Carlos O. Velásquez-Santos

    2014-08-01

    Full Text Available The article describes two important issues, the first is the process to design, implement and validate a mechanical dryer of oregano, using propane gas as fuel, and the second is the cost of the process of dehydrated, taking into account the cost of electric energy consumption by the fan and the cost of propane gas consumption by the heat exchanger. To achieve this, it was necessary review the state of the art and the study of the raw material (oregano, were established as premises of design the necessary technical specifications and the variables involved in the process, using conceptual methods and simulation to ensure that it complies with the ISO standard 7925:1999, which defines the requirements for the marketing of dried oregano and processed. Emphasis was made on the percentage of moisture that is 10%, the moisture of the product was found by the azeotropic distillation method, subsequently was validated the functionality and efficiency, comparing the results from an experimental design, then it was obtained the drying curve of oregano with the prototype of drying and it was checked if it meets ISO 7925:1999 standard and the NTC 4423 standard in order to obtain a final product dehydrated with the percentage of humidity appropriate.

  3. Experimental measurement of vapor pressures and (vapor + liquid) equilibrium for {l_brace}1,1,1,2-tetrafluoroethane (R134a) + propane (R290){r_brace} by a recirculation apparatus with view windows

    Energy Technology Data Exchange (ETDEWEB)

    Dong Xueqiang [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, P.O. Box 2711, Beijing 100190 (China); Graduate University of Chinese Academy of Sciences, Beijing 100039 (China); Gong Maoqiong, E-mail: gongmq@mail.ipc.ac.c [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, P.O. Box 2711, Beijing 100190 (China); Liu Junsheng [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, P.O. Box 2711, Beijing 100190 (China); Graduate University of Chinese Academy of Sciences, Beijing 100039 (China); Wu Jianfeng, E-mail: jfwu@mail.ipc.ac.c [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, P.O. Box 2711, Beijing 100190 (China)

    2011-03-15

    The saturated vapor pressures of 1,1,1,2-tetrafluoroethane (R134a) and propane (R290), and the (vapor + liquid) equilibrium (VLE) data at (255.000, 265.000, 275.000, and 285.000) K for the (R134a + R290) system were measured by a recirculation apparatus with view windows. The uncertainty of the temperatures, pressures, and compositions are less than {+-}5 mK, {+-}0.0005 MPa, and {+-}0.005, respectively. The saturated vapor pressures data were correlated by a Wagner type equation and compared with the reference data. The binary VLE data were correlated with the Peng-Robinson equation of state (PR EoS) incorporating the Huron-Vidal (HV) mixing rule utilizing the nonrandom two-liquid (NRTL) activity coefficient model. For mixtures, the maximum average absolute relative deviation of pressure is 0.15%, while the maximum average absolute deviation of vapor phase mole fraction is 0.0045. Azeotropic behavior can be found for the (R134a + R290) system at measured temperatures.

  4. The element technology of clean fuel alcohol plant construction

    Energy Technology Data Exchange (ETDEWEB)

    Lee, D.S; Lee, D.S. [Sam-Sung Engineering Technical Institute (Korea, Republic of); Choi, C.Y [Seoul National University, Seoul (Korea, Republic of)] [and others

    1996-02-01

    The fuel alcohol has been highlighted as a clean energy among new renewable energy sources. However, the production of the fuel alcohol has following problems; (i)bulk distillate remains is generated and (ii) benzene to be used as a entertainer in the azeotropic distillation causes the environmental problem. Thus, we started this research on the ground of preserving the cleanness in the production of fuel alcohol, a clean energy. We examined the schemes of replacing the azotropic distillation column which causes the problems with MSDP(Molecular Sieve Dehydration Process) system using adsorption technology and of treating the bulk distillate remains to be generated as by-products. In addition, we need to develop the continuous yea station technology for the continuous operation of fuel alcohol plant as a side goal. Thus, we try to develop a continuous ethanol fermentation process by high-density cell culture from tapioca, a industrial substrate, using cohesive yeast. For this purpose, we intend to examine the problem of tapioca, a industrial substrate, where a solid is existed and develop a new process which can solve the problem. Ultimately, the object of this project is to develop each element technology for the construction of fuel alcohol plant and obtain the ability to design the whole plant. (author) 54 refs., 143 figs., 34 tabs.

  5. Pinch Point Calculations and Its Implications on Robust Distillation Design

    Institute of Scientific and Technical Information of China (English)

    Daniel A. Beneke; Seon B. Kim; Andreas A. Linninger

    2011-01-01

    Rising energy costs and growing environmental awareness motivate a critical revision of the design of distillation units. Systematic design techniques, such as the rectification body, column profile map, and temperature collocation methods, require exact knowledge of all pinch points in a particular system, because these stationary points delineate the possible composition trajectories realizable in separation columns. This paper demonstrates novel methods for rigorously determining all pinch points for the constant relative volatility, ideal and non-ideal systems. Constant relative volatility and ideal solution systems are transformed into one-dimensional polynomial and nonlinear functions, regardless of the number of the components. A deflation method is proposed to locate all zeros in ideal and non-ideal zeotropic problems. For more challenging non-ideal problems, a novel hybrid sequential niche algorithm is used to solve hard azeotropic problems successfully. Finally, the design implications of these pinch point locations are investigated to show how new separation configurations can be devised. Methodically the paper points out the use of rigorous pinch point computations in conjunction with continuous composition profiles for robust distillation design.

  6. Skin efficacy of liposomes composed of internal wool lipids rich in ceramides.

    Science.gov (United States)

    Ramírez, R; Martí, M; Barba, C; Méndez, S; Parra, J L; Coderch, L

    2010-01-01

    Ceramides from intercellular lipids of skin stratum corneum are known to play an essential role in maintaining and structuring the lipid barrier of the skin. Internal wool lipids (IWL), which are also rich in ceramides, have a composition similar to that of the stratum corneum lipids. IWL extracted with chloroform/methanol azeotrope at the laboratory scale have been shown to be capable of forming liposomes with a stable bilayer structure. Furthermore, topical application of these IWL liposomes on intact and compromised skin has been demonstrated to improve barrier skin properties.In this study we evaluated the effect on human skin repair of different IWL extract compositions obtained by two extraction methodologies. The formation and characteristics of the liposomes prepared were greatly influenced by the IWL composition, primarily the sterol sulfate content. The IWL liposomes improved skin barrier integrity and increased skin hydration when applied onto intact skin. These improvements were slightly enhanced in the case of IWL liposomes that were richer in polar lipids.

  7. Biodiesel Production from Waste Edible Oils and Grease Containing Free Fatty Acids

    Institute of Scientific and Technical Information of China (English)

    Huang Fenghong; Guo Pingmei; Huang Qingde

    2005-01-01

    Till now, most part of the biodiesel is produced from the refined vegetable oils using methanol as feedstock in the presence of an alkali catalyst. However, large amount of waste edible oils and grease are available. The difficulty with alkali-catalyzed esterification of these oils is that they often contain large amount of free fatty acids (FFA), polymers and decomposition products. These free fatty acids can quickly react with the alkali catalyst to produce soaps that inhibit the separation of the ester and glycerine. An esterification and transesterification process is developed to convert the high FFA oil to its monoesters. The first step, the acidcatalyzed esterification with glycerine and these FFA reduces the FFA content of the oil and grease to less than3%, and then an azeotropic distillation solvent is used to remove the water. The major factors affecting the conversion efficiency of the process such as glycerol to free fatty acid molar ratio, catalyst amount, reaction temperature and reaction duration are analyzed. The second step, alkali-catalyzed transesterification process converts the products of the first step to its monoesters and glycerol, and then the glycerol is recycled for utilization in the first step. Technical indicators of the biodiesel product can meet the ASTM 6751 standard.

  8. Experimental study and modelling of heat transfer during condensation of pure fluid and binary mixture on a bundle of horizontal finned tubes

    Energy Technology Data Exchange (ETDEWEB)

    Belghazi, M.; Marvillet, C. [Commissariat a l' Energie Atomique, Grenoble (France). Groupement pour la Recherche sur les Echangeurs thermiques; Bontemps, A. [Universite Joseph Fourier, Grenoble (France). LEGI/GRETh

    2003-03-01

    An experimental investigation was conducted to measure the local heat transfer coefficient for each row in a trapezoidal finned horizontal tube bundle during condensation of both pure fluid (HFC 134a) and several compositions of the non-azeotropic binary mixture HFC 23/HFC 134a. The test section is a 13x3 (rows x columns) tube bundle and the heat transfer coefficient is measured using the modified Wilson plot method. The inlet vapour temperature is fixed at 40{sup o}C and the water flow rate in each active row ranges from 170 to 600 l/h. The test series cover five different finned tubes all commercially available, K11 (11 fins/inch), K19 (19 fins/inch), K26 (26 fins/inch), K32 (32 fins/inch), K40 (40 fins/inch) and their performances were compared. The experimental results were checked against available models predicting the heat transfer coefficient during condensation of pure fluids on banks of finned tubes. Modelling of heat exchange during condensation of binary mixtures on bundles of finned tubes based on the curve condensation model is presented. (author)

  9. Separation of ethanol and water by extractive distillation with salt and solvent as entrainer: process simulation

    Directory of Open Access Journals (Sweden)

    I. D. Gil

    2008-03-01

    Full Text Available The aim of this work is to simulate and analyze an extractive distillation process for azeotropic ethanol dehydration with ethylene glycol and calcium chloride mixture as entrainer. The work was developed with Aspen Plus® simulator version 11.1. Calculation of the activity coefficients employed to describe vapor liquid equilibrium of ethanol - water - ethylene glycol - calcium chloride system was done with the NRTL-E equation and they were validated with experimental data. The dehydration process used two columns: the main extractive column and the recovery column. The solvent to feed molar ratio S/F=0.3, molar reflux ratio RR=0.35, number of theoretical stages Ns=18, feed stage Sf=12, feed solvent stage SS=3, and feed solvent temperature TS=80 ºC, were determined to obtain a distillate with at least 99.5 % mole of ethanol. A substantial reduction in the energy consumption, compared with the conventional processes, was predicted by using ethylene glycol and calcium chloride as entrainer.

  10. Producing fuel alcohol by extractive distillation: Simulating the process with glycerol

    Directory of Open Access Journals (Sweden)

    Ana María Uyazán

    2010-07-01

    Full Text Available Downstream separation processes in biotechnology form part of the stages having most impact on a product’s final cost. The tendency throughout the world today is to replace fossil fuels with those having a renewable origin such as ethanol; this, in turn, produces a demand for the same and the need for optimising fermentation, treating vinazas and dehydration processes. The present work approaches the problem of dehydration through simulating azeotropic ethanol extractive distillation using glycerol as separation agent. Simulations were done on an Aspen Plus process simulator (Aspen Tech version 11.1. The simulated process involves two distillation columns, a dehydrator and a glycerol recuperation column. Simulation restrictions were ethanol’s molar composition in dehydrator column distillate and the process’s energy consumption. The effect of molar reflux ratio, solvent-feed ratio, solvent entry and feed stage and solvent entry temperature were evaluated on the chosen restrictions. The results showed that the ethanol-water mixture dehydration with glycerol as separation agent is efficient from the energy point of view.

  11. Indium tin oxide nanosized composite powder prepared using waste ITO target

    Institute of Scientific and Technical Information of China (English)

    LIU Jiaxiang; GAN Yong; ZENG Shengnan

    2005-01-01

    Indium tin oxide (TTO) nano-particles were prepared directly using waste ITO target, which had been coated by magnetron controlled sputtering. The waste ITO target was cleaned with de-ionized water, and then dissolved in acid, filtrated, neutralized, manipulated through azeotropic distillation and finally dried, and in this way the precursor of indium tin hydroxide was obtained. The nanosized ITO composite powder was prepared after the precursor heat-treated at 500C for 2h. TEM images show a narrow distribution of particle size is 5-20 nm and the particle size can be controlled. Its granule has a spherical shape and the dispersion of the particle is well. X-ray diffraction (XRD) patterns indicate the only cubic In2O3 phase in the ITO powder heat-treated at 500C. The purity of ITO composite powder is 99.9907%. The content of indium within filtrate was detected by using the EDTA titration of determination of indium in the ITO powder and ITO target. Apfully prepared by heat-treating.

  12. Design and control of methyl acetate-methanol separation via heat-integrated pressure-swing distillation

    Institute of Scientific and Technical Information of China (English)

    Zhishan Zhang; Qingjun Zhang; Guijie Li; Meiling Liu; Jun Gao

    2016-01-01

    Design and control of pressure-swing distil ation (PSD) with different heat integration modes for the separation of methyl acetate/methanol azeotrope are explored using Aspen Plus and Aspen Dynamics. First, an optimum steady-state separation configuration conditions are obtained via taking the total annual cost (TAC) or total reboiler heat duty as the objective functions. The results show that about 27.68%and 25.40%saving in TAC can be achieved by the PSD with full and partial heat integration compared to PSD without heat integration. Second, temperature control tray locations are obtained according to the sensitivity criterion and singular value decom-position (SVD) analysis and the single-end control structure is effective based on the feed composition sensitivity analysis. Final y, the comparison of dynamic controllability is made among various control structures for PSD with partial and full heat integration. It is shown that both control structures of composition/temperature cascade and pressure-compensated temperature have a good dynamic response performance for PSD with heat integration facing feed flowrate and composition disturbances. However, PSD with full heat integration performs the poor control ability despite of a little bit of economy.

  13. Synthesis and Characterization of a Gasoline Oxygenate, Ethyl tert-Butyl Ether

    Science.gov (United States)

    Donahue, Craig J.; D'Amico, Teresa; Exline, Jennifer A.

    2002-06-01

    A laboratory procedure involving the synthesis and characterization of ethyl tert-butyl ether (ETBE) is described. This experiment has been used in a general chemistry sequence that includes a section on organic chemistry, but is also well suited for an introductory organic chemistry laboratory course. ETBE is prepared by the acid-catalyzed reaction of tert-butyl alcohol with ethyl alcohol. The product is recovered as a low-boiling azeotrope and purified by liquid liquid extraction with water. By using gas chromatography and IR spectroscopy to examine both the crude and the purified products, students can see how much the purity of their sample improves. They can also appreciate the value of these methods (especially GC) as tools to establish purity. Student results are presented. The use of ETBE and its more prominent cousin methyl tert-butyl ether (MTBE) as gasoline oxygenates has become very controversial because they have polluted underground water supplies. This lab permits students to prepare a compound that has a real use and regularly makes headlines in the news. This lab experiment is part of an effort to develop a general chemistry sequence for engineering students using the theme of "Chemistry and the Automobile".

  14. 固体超强酸SO42-/SnO2-Nb2O5的制备及其表征%PREPARATION AND CHARACTERIZATION OF SO42-/SnO2-Nb2O5 SOLID SUPERACID CATALYST

    Institute of Scientific and Technical Information of China (English)

    黄建团; 郭海福; 闫鹏; 陈志胜

    2012-01-01

    采用共沸除氯工艺制备SO42-/SnO2-Nb2O5固体超强酸,该方法引入共沸蒸馏,以正丁醇和无水乙醇为溶剂,锡盐醇溶液滴加氨水前除去其中结晶水再除氯离子,免去抽滤除氯步骤,缩短了催化剂制备时间.将制备的SO42-/SnO2-Nb2O5用于催化α-蒎烯的异构化反应,考察催化剂制备条件对催化剂活性的影响,采用FT-IR,XRD,TG-DTA等对催化剂的物化性质进行表征,并与沉淀法、sol-gel法制备的催化剂进行对比.结果表明:催化剂最佳制备条件为Nb2O5加入量为SnO2质量的25%、浸渍液硫酸浓度0.5 mol/L、焙烧温度500℃、焙烧时间2h,将该条件下制备的SO42-/SnO2-Nb2O5应用于催化α-蒎烯异构化反应时,α-蒎烯完全转化,莰烯选择性为66.49%;与沉淀法、sol-gel法相比,相同条件下共沸除氯法制备的催化剂较好.%SO42-/SnO2-Nb2O5 solid superacid catalyst was prepared by azeotropic dechlorination method, using w-butanol and anhydrous alcohol as solvents, a filtration step could be omitted, and thus the catalyst preparation time was much shortened. The prepared catalyst was characterized by XRD, FT-IR, TG-DTA and its catalytic performance was evaluated using isomerization of a-pinene as probe reaction. Test results showed that the optimum preparation conditions of SO42-/SnO2-Nb2O5 solid superacid catalyst were as follows: a Nb2O5/SnO2 mass ratio of 0. 25, the concentration of impregnating sulfuric acid solution was 0. 50 mol/L and calcined at 500 ℃ for 2. 0 h; catalyst prepared under such conditions exhibited good catalytic performance in isomerization of crpinene, the conversion of α-pinene and selectivity of camphene was 100% and 66.49%, respectively. Compared with other preparation methods, such as precipitation and sol-gel methods, catalyst prepared by azeotropic dechlorination method was better.

  15. EXTRACTIVE DISTILLATION PROCESS SIMULATION FOR SEPARATION OF DICHLOROMETHANE AND ACETONE%萃取精馏分离二氯甲烷-丙酮的工艺模拟

    Institute of Scientific and Technical Information of China (English)

    王震; 高晓冲; 夏庆宁; 高瑞昶

    2012-01-01

    Dichloromethane and acetone can form the highest azeotrope, so it can not be separated by conventional distillation. Extractive distillation for separation of dichloromethane and acetone was simulated by computer. Wilson model and NRTL model were used for predicting VLE and LLE. The influence of operation factors such as stage number, reflux ratio, extractant feed rate, location, temperature and material feed location, temperature were analyzed. The optimal parameters of column were proposed: the theoretical total plate number of extraction column is 36, the reflux ratio is 3, the raw material is fed at 16th plate, the extractant is fed at 7th plate and the feed rate is 1 500 kg/h. Di-chloromethane-water azeotrope was obtained at the top of the extraction column. The dichloromethane layer was 99. 9%. Acetone-water mixture which was obtained at the bottom of extraction column was put into the acetone column, the theoretical total plate number of acetone column is 35, the reflux ratio is 4, and the raw material is fed at 25th plate. A top product of acetone with 99. 7% concentration and a bottom product of almost pure water which can be recycled as extraction water after cooling could be obtained. These results are useful for construction design and improvement.%以水为萃取剂对二氯甲烷丙酮混合物进行了萃取精馏过程模拟,体系的气-液平衡和液液平衡分别采用Wilson模型和NRTL模型预测.分析了总理论板数,回流比,萃取剂进料速率、塔板数、温度和原料进料塔板数、温度等操作参数对精馏过程的影响.并取得了最佳工艺参数为:萃取塔采用36块理论板,回流比为3,原料在第16块板进料,萃取剂用量1 500 kg/h,第7块板进料时塔顶得到二氯甲烷-水的共沸物,分层得99.9%的二氯甲烷,塔釜得到丙酮-水的混合物进入丙酮塔;丙酮塔为简单精馏塔,采用35块理论板,回流比为4,第25块板进料,塔顶可得99.7%的丙酮,塔釜得到几乎

  16. Ni2P/Al-MCM-41催化剂的制备及其加氢脱硫性能%Preparation and hydrodesulfurization performance of Al-MCM-41 supported nickel phosphide catalysts

    Institute of Scientific and Technical Information of China (English)

    匡志敏; 龚建议; 杨运泉; 王威燕; 陈来福; 贺恒

    2011-01-01

    A1-MCM-41 mesoporous molecular sieves were prepared by the azeotropic distillation and ultrasonic dispersive technology using sodium silicate as silica source , aluminum sulfate as aluminum source and cetyltrimethyl ammonium bromide as structure-directing agent. By using A1-MCM-41 as support, nickel nitrate and diammonium hydrogen phosphate as raw materials, a series of supported Ni2P catalysts on A1-MCM-41 was prepared via the method of temperature-programmed reduction under ultrasonic oscillation. The catalysts were characterized by FT1R, BET, XRD and SEM.Hydrodesulfurization of thiophene catalyzed by Ni2P/Al-MCM-41 was carried out in a high pressure autoclave reactor. The experimental results showed that Al-MCM-41 prepared by ultrasonic dispersive technology had a much higher specific surface area, larger pore volume and pore diameter than that prepared by conventional mechanical mixing. The Al-MCM-41 prepared by azeotropic distillation with ultrasonic dispersive technology was also better than that using only ultrasonic dispersive technology.The Ni2P/A1-MCM-41 catalysts, hydrodesulfurization conversion of thiophene nearly reached 100% at the reaction time 5 h, reaction temperature 548 K, and reaction pressure 3.5 MPa.%以硅酸钠为硅源、硫酸铝为铝源、十六烷基三甲基溴化铵(CTAB)作模板剂,采用共沸蒸馏与超声波分散技术相结合的方法制备了介孔分子筛Al-MCM-41.以Al-MCM-41为载体,硝酸镍和磷酸氢二氨为原料,采用超声波振荡、程序升温还原法制备了Ni2P/Al-MCM-41催化剂,并对Al-MCM-41和Ni2P/Al-MCM-41进行了傅里叶变换红外光谱、比表面积测定、X射线衍射、扫描电镜表征.考察了Ni2P/Al-MCM-41催化剂对噻吩加氢脱硫的催化性能.结果表明:采用超声波制得的Al-MCM-41其比表面积,孔容和孔径明显高于常规搅拌制得的Al-MCM-41,共沸蒸馏制得的Al-MCM-41其比表面积、孔容和孔径高于未共沸蒸馏的Al-MCM-41;

  17. 萃取精馏分离丙酮-四氢呋喃的研究%Separation of acetone-tetrahydrofuran by extractive distillation

    Institute of Scientific and Technical Information of China (English)

    刘岩; 白鹏

    2012-01-01

    In order to separate acetone-tetrahydrofuran mixture, ethylbenzene as the solvent for separating acetone-tetrahydrofuran mixture by extractive distillation was chosen according to the basic selection rules. The simulation of vapor-liquid equilibrium using NRTL model for acetone-tetrahydrofuran system with and without ethylbenzene under atmospheric pressure and the vapor-liquid equilibrium experiment were performed. The simulation results agree well with the experimental data. The effectiveness of the solvent selected was also investigated by the batch extractive distillation experiments. The results show that ethylbenzene can eliminate the azeotropic point of acetone-tetrahydrofuran system. The batch distillation was carried out in a packed column of 40 theoretical plates. With the reflux ratio of 5 and the solvent mole ratio of 2. 5 : 1 ,the product mass fraction of acetone reaches 99. 34% , which reveals that the extractive distillation with ethylbenzene as solvent is useful in the separation of acetone-tetrahydrofuran. At last,the flow sheet of separating this azeotrope by batch and continual extractive distillation were simulated. The technological parameters obtained can provide the theoretical basis for further industrial application.%为了分离丙酮-四氢呋喃共沸混合物,研究了萃取精馏在丙酮-四氢呋喃物系中的应用.通过溶剂选择原理初选出乙苯作为萃取精馏分离此共沸物系的溶剂,同时采用NRTL模型对常压下丙酮-四氢呋喃物系和加入溶剂乙苯后的汽液平衡进行模拟和实验验证,模拟结果与实验数据吻合较好.然后进行了间歇萃取精馏分离此共沸物的实验研究来进一步考察所选萃取剂的效果.结果表明:乙苯能够消除丙酮-四氢呋喃共沸物系的共沸点,采用有40块理论板的填料塔,回流比为5,溶剂摩尔比为2.5∶1时塔顶可以得到质量分数为99.34%的丙酮产品,说明采用乙苯作萃取剂分离丙

  18. Ebulliometric determination and prediction of (vapor + liquid) equilibria for binary and ternary mixtures containing alcohols (C{sub 1}-C{sub 4}) and dimethyl carbonate

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Hiroyuki, E-mail: matsuda@chem.cst.nihon-u.ac.jp [Department of Materials and Applied Chemistry, Nihon University, 1-8 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Fukano, Makoto; Kikkawa, Shinichiro [Department of Materials and Applied Chemistry, Nihon University, 1-8 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Constantinescu, Dana [Carl von Ossietzky Universitaet Oldenburg, Technische Chemie, D-26111 Oldenburg (Germany); Kurihara, Kiyofumi; Tochigi, Katsumi; Ochi, Kenji [Department of Materials and Applied Chemistry, Nihon University, 1-8 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Gmehling, Juergen [Carl von Ossietzky Universitaet Oldenburg, Technische Chemie, D-26111 Oldenburg (Germany)

    2012-01-15

    Highlights: > The VLE behavior of systems containing dimethyl carbonate (DMC) was investigated. > VLE data for ternary and binary mixtures containing alcohol and DMC were measured. > Several activity coefficient models were used for data reduction or prediction. > Valley line, i.e., distillation boundary, was observed for the ternary mixture. > Residue curves were calculated to investigate composition profile for distillation. - Abstract: (Vapor + liquid) equilibrium (VLE) data for a ternary mixture, namely {l_brace}methanol + propan-1-ol + dimethyl carbonate (DMC){r_brace}, and four binary mixtures, namely an {l_brace}alcohol (C{sub 3} or C{sub 4}) + DMC{r_brace}, containing the binary constituent mixtures of the ternary mixture, were measured at p = (40.00 to 93.32) kPa using a modified Swietoslawski-type ebulliometer. The experimental data for the binary systems were correlated using the Wilson model. The Wilson model was also applied to the ternary system to predict the VLE behavior using parameters from the binary mixtures. The modified UNIFAC (Dortmund) model was also tested for the predictions of the VLE behavior of the binary and ternary mixtures. In addition, the experimental VLE data for the ternary and constituent binary mixtures were correlated using the extended Redlich-Kister (ERK) model, which can completely represent the azeotropic points. For the ternary system, a comparison of the experimental and the predicted or correlated boiling points obtained using the Wilson and ERK models showed that the ERK model is more accurate. The valley line, i.e., the curve which divides the patterns of vapor-liquid tie lines, was found in the (methanol + propan-1-ol + DMC) system. This valley line could be represented by the ERK model. Finally, the composition profile for simple distillation of this ternary mixture was obtained by analysis of the residue curves from the estimated Wilson parameters of the constituent binary mixtures.

  19. Toxicity Data to Determine Refrigerant Concentration Limits

    Energy Technology Data Exchange (ETDEWEB)

    Calm, James M.

    2000-09-30

    This report reviews toxicity data, identifies sources for them, and presents resulting exposure limits for refrigerants for consideration by qualified parties in developing safety guides, standards, codes, and regulations. It outlines a method to calculate an acute toxicity exposure limit (ATEL) and from it a recommended refrigerant concentration limit (RCL) for emergency exposures. The report focuses on acute toxicity with particular attention to lethality, cardiac sensitization, anesthetic and central nervous system effects, and other escape-impairing effects. It addresses R-11, R-12, R-22, R-23, R-113, R-114, R-116, R-123, R-124, R-125, R-134, R-134a, R-E134, R-141b, R-142b, R-143a, R-152a, R-218, R-227ea, R-236fa, R-245ca, R-245fa, R-290, R-500, R-502, R-600a, R-717, and R-744. It summarizes additional data for R-14, R-115, R-170 (ethane), R-C318, R-600 (n-butane), and R-1270 (propylene) to enable calculation of limits for blends incorporating them. The report summarizes the data a nd related safety information, including classifications and flammability data. It also presents a series of tables with proposed ATEL and RCL concentrations-in dimensionless form and the latter also in both metric (SI) and inch-pound (IP) units of measure-for both the cited refrigerants and 66 zerotropic and azeotropic blends. They include common refrigerants, such as R-404A, R-407C, R-410A, and R-507A, as well as others in commercial or developmental status. Appendices provide profiles for the cited single-compound refrigerants and for R-500 and R-502 as well as narrative toxicity summaries for common refrigerants. The report includes an extensive set of references.

  20. Lanthanum(III) catalysts for highly efficient and chemoselective transesterification.

    Science.gov (United States)

    Hatano, Manabu; Ishihara, Kazuaki

    2013-03-11

    A facile, atom-economical, and chemoselective esterification is crucial in modern organic synthesis, particularly in the areas of pharmaceutical, polymer, and material science. However, a truly practical catalytic transesterification of carboxylic esters with various alcohols has not yet been well established, since, with many conventional catalysts, the substrates are limited to 1°- and cyclic 2°-alcohols. In sharp contrast, if we take advantage of the high catalytic activities of La(Oi-Pr)(3), La(OTf)(3), and La(NO(3))(3) as ligand-free catalysts, ligand-assisted or additive-enhanced lanthanum(III) catalysts can be highly effective acid-base combined catalysts in transesterification. A highly active dinuclear La(III) catalyst, which is prepared in situ from lanthanum(III) isopropoxide and 2-(2-methoxyethoxy)ethanol, is effective for the practical transesterification of methyl carboxylates, ethyl acetate, weakly reactive dimethyl carbonate, and much less-reactive methyl carbamates with 1°-, 2°-, and 3°-alcohols. As the second generation, nearly neutral "lanthanum(III) nitrate alkoxide", namely La(OR)(m)(NO(3))(3-m), has been developed. This catalyst is prepared in situ from inexpensive, stable, low-toxic lanthanum(III) nitrate hydrate and methyltrioctylphosphonium methyl carbonate, and is highly useful in the non-epimerized transesterification of α-substituted chiral carboxylic esters, even under azeotropic reflux conditions. In these practical La(III)-catalyzed transesterifications, colorless esters can be obtained in small- to large-scale synthesis without the need for inconvenient work-up or careful purification procedures.

  1. Experimental study on the adsorptive-distillation for dehydration of ethanol-water mixture using natural and synthetic zeolites

    Science.gov (United States)

    Megawati, Wicaksono, D.; Abdullah, M. S.

    2017-03-01

    This research studied adsorptive-distillation (AD) for dehydration of ethanol-water mixture using natural and synthetic zeolites as adsorbent for ethanol purification. Especially, the effect of purification time is recorded and studied to evaluate performance of designed AD equipment. This AD was performed in a batch condition using boiling flask covered with heating mantle and it was maintained at 78°C temperature and 1 atm pressure. The initial ethanol volume was 300 mL with 93.8% v/v concentration. The synthetic zeolite type used was zeolite 3A. The flowed vapour was condensed using water as a cooling medium. Every 5 minutes of time duration the samples were collected until the vapour could not be condensed in that condition and then be analyzed its concentration using Gas-Chromatography. Experiment shows that the designed AD equipment could increase ethanol concentration at first 5 minutes with highest ethanol concentration achieved using synthetic zeolite (97.47% v/v). However, ethanol concentration from AD process using natural zeolite only reached 96.5% v/v. Thus, synthetic zeolite as adsorbent could pass azeotropic point, but natural zeolite fail. The ratio of adsorbed water per adsorbent for natural and synthetic zeolites are about 0.023 and 0.056 gwater/gads, respectively, at 50 minutes of time. Finally, synthetic zeolite (at 55 minutes the value of C/C0 is about 0.85 and the average outlet water concentration is 4.70 mole/L) as adsorbent for AD of ethanol water is better than natural zeolite (at 55 minutes the value of C/C0 is about 0.63 and the average outlet water concentration is 6.43 mole/L).

  2. Method for Extracting Nano γ -Al2O3 by Oil Shale Ash%油页岩灰渣制备纳米γ-Al2O3的方法研究

    Institute of Scientific and Technical Information of China (English)

    季桂娟; 郝磊; 李晓军; 高桂梅; 甘树才

    2011-01-01

    本文研究了以油页岩灰渣为原料提取纳米γ -Al2O3的方法,该方法包括浸取和烧结两个步骤.以表面活性剂进行表面改性,辅以超声震荡,最后以正丁醇为置换剂进行共沸蒸馏去除前躯体表面的羟基以及吸附的水分子.用X-射线衍射、透射扫描电镜、比表面积(BET)检测手段对制备出的氧化铝纳米粉末进行了分析.试验结果表明,所得的纳米氧化铝分散均匀,粒径为20 ~ 40nm.%A combined process was proposed for the utilization of waste oil shale ash (OS A) in the production of y -A12O3 nanoparticles. The process consisted of two stages, leaching and sintering. The ultrasonic technique followed by a heterogeneous azeotropic distillation process in the presence of polyethylene glycol (PEG) was carried to ensure complete elimination of the residual water in the precipitate. The structural and morphological properties of the calcined nanocrystalline powders were characterized by X-ray diffractometer (XRD), transmission electron microscope (TEM), Brunauer-Emmett-Teller nitrogen-gas adsorption method (BET). The results indicated that the y -A12O3 powder with a uniform particle was well dispersed and the particle size was 20~40nm.

  3. Highly Efficient Esterification of an Equimolar Amount of Carboxylic Acids and Alcohols Catalyzed by ZrOCl2·8H2O

    Institute of Scientific and Technical Information of China (English)

    Sun Hong-Bin; Hua Ruimao; Yin Ying-Wu

    2004-01-01

    Esterification of carboxylic acids with alcohols is one of the most fundamental and useful transformations in organic synthesis. The most common catalysts are H2SO4 and TsOH. However,H2SO4 or TsOH-catalyzed esterification procedure has some problems such as corrosion, side reactions, difficulty in separation. Hence, recently, various solid acid catalysts such as ion-exchanged resins, molecular sieve, and heteropoly acids etc. have been employed for esterification reaction.However, the solid acid catalysts are usually not easily accessible and expensive In addition, for achieving the high yield of esters, it is usually to carry out the esterification reaction by addition of an excess of one of the reactants. Therefore it is still interesting to develop the high activity,cost-effective catalyst system.which is a commercially available and very cheap inorganic salt.The esterification was carried out in the presence of ZrOCl2. 8H2O (0.05 mol %) using equimolar amount of carboxylic acids and alcohols at room temperature or at 50℃. For example, the esterification of propionic acid with methanol at room temperature for 24 h gave methyl propionate in 81% GC yield. A higher yield of esters can be obtained by the removal of water azeotropically.The present esterification procedure has the following advantages:1) Esters can be obtained in high yield with the use of equimolar amount of carboxylic acids and alcohols.2) Esterification proceeds at room temperature, the catalyst system is suitable for the esterification of highly reactive carboxylic acids such as acrylic acid.3) It is easy to isolate and purify the esters, and the catalyst is recyclable. The complete reaction mixture becomes two phases at room temperature, the esters in the organic phase can be separated conveniently by decanting, and the catalyst in the water can be reused without any treatment.

  4. Stereochemical features of unsaturated aminodiesters - intermediates in the synthesis of Richlocaine

    Directory of Open Access Journals (Sweden)

    Meyrambek Ospanov

    2014-10-01

    Full Text Available The article provides information on the methods for synthesis of unsaturated aminodiesters, which are the key intermediates in the synthesis of N-substituted 2,5-dimethyl-piperidin-4-ones, including 1,2,5-trimetilpieridin-3-one. The developed method includes reaction of methyl ester of methacrylic acid with alkyl (alkenyl amines. The obtained N-alkyl(alkenyl-(2-methyl-2- carbmetoxyethyl methylamine are attached to acetoacetic ester being in the enol form. The optimal conditions for synthesis of N-alkyl(alkenyl-(2-methyl-2-carbethoxyethenemethylamines have been established. Results of gas chromatographic analysis has showed that, at room temperature, the reaction in polar solvents is delayed for two days. In non-polar solvents, the reaction runs with simultaneous distillation of water as an azeotrope with the solvent. Increase of the radical size at N atom has little effect on the reaction rate. Introduction of allyl radical at the nitrogen atom, apparently due to steric hindrance, resulted in lower reactivity of the monoester with allyl radical by condensation with acetoacetic ester. The structure of (1-methyl-2-carbethoxyethene-(2-methyl-2-carbmethoxyethyl methylamine has been studied by PMR spectroscopy. Study of the effect of chirality on the NMR spectra showed that, if the molecule of the organic compound has an asymmetric carbon atom, it may lead to the disappearance of the magnetic equivalence of neighboring protons or group of protons. Presence of an asymmetric carbon atom in b-position to the amino group of enamine leads to the disappearance of the magnetic equivalence of the neighboring protons is observed in the form of two quartets. For enaminodiesters, equilibrium is shifted toward the trans-S-cis conformer where less steric hindrance is pronounced.

  5. Preliminary results from bench-scale testing of a sulfur-iodine thermochemical water-splitting cycle

    Energy Technology Data Exchange (ETDEWEB)

    O' Keefe, D.; Allen, C.; Besenbruch, G.; McCorkle, K.; Norman, J.; Sharp, R.

    1980-07-01

    Portions of a bench-scale model of a sulfur-iodine thermochemical water-splitting cycle have been operated at General Atomic Company as part of a comprehensive program to demonstrate the technology for hydrogen production from nonfossil sources. The hydrogen program is funded by the US Department of Energy, the Gas Research Institute, and General Atomic Company. The bench-scale model consists of three subunits which can be operated separately or together and is capable of producing as much as 4 std liters/min (6.7 x 10/sup -5/ m/sup 3//s at standard conditions) of gaseous hydrogen. One subunit (main solution reaction) reacts liquid water, liquid iodine (I/sub 2/) and gaseous sulfur dioxide (SO/sub 2/) to form two separable liquid phases: 50 wt % sulfuric acid (H/sub 2/SO/sub 4/) and a solution of iodine in hydriodic acid (HI/sub x/). Another subunit (H/sub 2/SO/sub 4/ concentration and decomposition) concentrates the H/sub 2/SO/sub 4/ phase to the azeotropic composition, then decomposes it at high temperature over a catalyst to form gaseous SO/sub 2/ and oxygen. The third subunit (HI separation and decomposition) separates the HI from water and I/sub 2/ by extractive distillation with phosphoric acid (H/sub 3/PO/sub 4/) and decomposes the HI in the vapor phase over a catalyst to form I/sub 2/ and product hydrogen. This paper presents the results of on-going parametric studies to determine the operating characteristics, performance, and capacity limitations of major components.

  6. Theoretical studies on new refrigerant in refrigeration system for freeze and cold storage%用于冷冻冷藏制冷系统的新型制冷剂的理论研究

    Institute of Scientific and Technical Information of China (English)

    高赞军; 徐英杰; 仇宇; 李鹏; 韩晓红; 陈光明

    2012-01-01

    综述在冷冻冷藏系统中制冷剂替代研究的现状.在此基础上,提出一种新的混合制冷剂(HFG-161/HFC-125/HFC-143a,15/45/40)用于替代HFC-404A,该新型制冷剂的ODP为零,GWP比HFC-404A和R507A要小,其基本热力学性能与HFC-404A相近.对新型混合制冷剂和HFC-404A的循环性能进行理论分析与比较.结果表明,新型混合制冷剂的性能要比HFC-404A优越,环境性能更好,是HFC-404A潜有力的替代制冷剂.%The research status on refrigerant substitute for the freeze and cold storage system is reviewed. Based on this,a new ternary non-azeotropic mixture of HFC-161/HFC-125/HFC-143a( 15/45/40) as a promising mixed refrigerant to HFO404A is presented. The ODP of the new refrigerant is zero and its basic thermodynamic properties are similar to those of HFC-404A,and its GWP is much smaller than that of R507A or HFC-404A. The cycle performance between the new mixture refrigerant and HFC-404A is theoretically analyzed and compared. The results show that the cycle performance and environmental performance of the new mixture refrigerant are better than those of HFC-404A. The new mixture refrigerant may be a promising alternative refrigerant for HFC-404A.

  7. Separation and simulation of products from direct cyclization of ethylenediamine%乙二胺直接环化产物的分离与模拟

    Institute of Scientific and Technical Information of China (English)

    田忠社; 梁建国; 韦雄雄; 刘荣杰; 郝红

    2012-01-01

    With toluene as entrainer, the batch azeotropic distillation was put forward to remove the ethylenediamine and crystal water of the mixture. Piperazine with mass fraction of 96.79% and triethylenediamine with mass fraction of 98.26% were finally obtained, and the entrainer recycling was achieved with water as extraction solvent. Aspen Plus chemical process simulation software was applied to simulate the distillation process so as to design the industrial experimental device including four columns for distillation and separation with entrainer recycling. Sensitivity analytic module was used for operational parameters optimization of the column, and the mass fraction of piperazine and triethylenediamine obtained reaches 98. 60% and 99.20% respectively.%提出以甲苯为共沸剂去除混合溶液中的乙二胺和结晶水的间歇共沸精馏法,最后得到质量分数为96.79%的哌嗪及98.26%三乙烯二胺产品,并以水为萃取剂,实现共沸剂的回收利用.采用Aspen Plus化工模拟软件对精馏分离过程进行模拟计算,设计了4塔精馏分离及共沸剂回收的工业化实验装置,利用灵敏度分析模块对精馏塔各操作参数进行优化,从而获得质量分数分别为98.60%和99.20%的哌嗪和三乙烯二胺产品.

  8. Identification and separation of the organic compounds in coal-gasification condensate waters. [5,5 dimethyl hydantoin, dihydroxy benzenes, acetonitrile

    Energy Technology Data Exchange (ETDEWEB)

    Mohr, D.H. Jr.; King, C.J.

    1983-08-01

    A substantial fraction of the organic solutes in condensate waters from low-temperature coal-gasification processes are not identified by commonly employed analytical techniques, have low distriution coefficients (K/sub C/) into diisopropyl ether (DIPE) or methyl isobutyl ketone (MIBK), and are resistant to biological oxidation. These compounds represent an important wastewater-treatment problem. Analytical techniques were developed to detect these polar compounds, and the liquid-liquid phase equilibria were measured with several solvents. A high-performance liquid - chromatography (HPLC) technique was employed to analyze four condensate-water samples from a slagging fixed-bed gasifier. A novel sample-preparation technique, consisting of an azeotropic distillation with isopropanol, allowed identification of compounds in the HPLC eluant by combined gas chromatography and mass spectrometry. 5,5-dimethyl hydantoin and related compounds were identified in condensate waters for the first time, and they account for 1 to 6% of the chemical oxygen demand (COD). Dimethyl hydatoin has a K/sub D/ of 2.6 into tributyl phosphate (TBP) and much lower K/sub D/ values into six other solvents. It is also resistant to biological oxidation. Phenols (59 to 76% of the COD), dihydroxy benzenes (0.02 to 9.5% of the COD), and methanol, acetonitrile, and acetone (15% of the COD in one sample) were also detected. Extraction with MIBK removed about 90% of the COD. MIBK has much higher K/sub D/ values than DIPE for dihydroxy benzenes. Chemical reactions occurred during storage of condensate-water samples. The reaction products had low K/sub D/ values into MIBK. About 10% of the COD had a K/sub D/ of nearly zero into MIBK. These compounds were not extracted by MIBK over a wide range of pH. 73 references, 6 figures, 35 tables.

  9. Synthesis of Ca(BH4)2 from Synthetic Colemanite Used in Hydrogen Storage by Mechanochemical Reaction

    Science.gov (United States)

    Karabulut, Ahmet F.; Guru, Metin; Boynueğri, Tuğba A.; Aydin, Mustafa Yasir

    2016-08-01

    In this study, synthesis of Ca(BH4)2 has been carried out with a solid phase reaction in which synthetic colemanite has been used as a raw material. Three dimensional high energy spex collider was selected for this mechanochemical reaction. Calcium borohydride is one of the most valuable metal borohydrides. In order to produce calcium borohydride economically, anhydrous colemanite mineral has been used as reactant. Calcium borohydride has been directly manufactured from anhydrous colemanite in spex-type ball milling without the need for any intermediate product. Thus, the advantages of this method over wet chemical procedure (such as having no intermediate product, no azeotropic limitations and no need of regaining product from solution after production by using evaporation, crystallization and drying processes) have made it possible to achieve the desired economical gains. Parametric experiments were conducted to determine the best conditions for the highest yield of solid phase reaction in the spex-type ball milling. Best results have been determined by using areas of related peaks in spectra of Fourier transform infrared spectroscopy (FT-IR). In order to use peaks area for determining Ca(BH4)2 concentration, a calibration graph of FT-IR absorbance peak areas has been created by using samples with known different concentrations of commercial Ca(BH4)2. Optimum amounts of calcium hydride and synthesis reaction time were found to be 2.1 times the stoichiometric ratio and 2500 min, respectively. As a result of these optimizations, the maximum yield of the solid phase reaction carried out by the spex-type ball milling has been determined as 93%.

  10. Studies on colour fixation of the oil of mature, immature and damaged cottonseed

    Directory of Open Access Journals (Sweden)

    Helmy, H. E.

    1994-06-01

    Full Text Available Oil was extracted from mature, inmature and damaged cottonseed with the acetone-hexane-water azeotrope (53:44:3 by volume. Mature cottonseed oil (M, 10% immature cottonseed oil in mature cottonseed oil (MIM and 10% damaged cottonseed oil in mature cottonseed oil (MD were subjected to some treatments e.g. refining and bleaching or the addition of sodium silicate before refining and bleaching or before colour fixation. The treated oils were spectrophotometrically studied.
    The presence of 10% oil from immature or damaged cottonseed in oil from mature cottonseed produced an increase in the colour and absorption spectra of most samples, resulting in an oil that could not be refined and bleached satisfactorily. Sodium silicate proved to be an effective treatment before refining and colour fixation of the oils. The study revealed gossypol pigments, carotenoids and chlorophylls present in different M, MIM and MD samples.

    Se extrajo aceite de semilla de algodón madura, Inmadura y dañada con el azeotropo, acetona-hexano-agua (53:44:3 v/v/v. Se sometieron a diversos tratamientos tales como refinación y decoloración, silicato sódico antes de la refinación y decoloración o antes de la fijación de color, a aceite de semilla de algodón madura (M, 10% de aceite de semilla de algodón inmadura en aceite de semilla de algodón madura (MIM y 10% de aceite de semilla de algodón dañada en aceite de semilla de algodón.
    madura (MD. Los aceites tratados se estudiaron espectrofotométricamente. La presencia de un 10% de aceite de semilla de algodón inmadura o dañada con aceite de semilla de algodón madura produjo un incremento en el color y en el espectro de absorción de la mayoría de las muestras, así ocurrió en un aceite que no pudo ser refinado y decolorado satisfactoriamente. El tratamiento con silicato sódico resultó efectivo antes de la refinación y fijación del color de los aceites. El estudio reveló la presencia de

  11. Vapor-Liquid Equilibrium for Methanol-Acetonitrile-1-Butyl-3-Methylimidazolium Tetrafluoroborate Ternary System%甲醇-乙腈-1-丁基-3-甲基咪唑四氟硼酸盐三组分物系的汽液平衡

    Institute of Scientific and Technical Information of China (English)

    李群生; 王海川; 冉晓萌; 朱炜; 付永泉; 王宝华

    2012-01-01

    在101.32 kPa下,用CE-2型Othmer汽液平衡釜测定了甲醇-乙腈-1-丁基-3-甲基咪唑四氟硼酸盐([bmim]BF4)三组分物系的等压汽液平衡数据;采用UNIFAC方程对实验数据进行了关联.实验结果表明,与未加入[bmim]BF4相比,加入[bmim]BF4后甲醇-乙腈二组分物系的汽液平衡线产生偏离,[bmim]BF4含量越高,偏离程度越大;[bmim]BF4具有明显的盐析效应,当[bmim]BF4的含量为10%(x)时,甲醇-乙腈物系的共沸点消失;UNIFAC方程可用于预测甲醇-乙腈-[bmim]BF4三组分物系的汽液平衡.%Isobaric vapor-liquid equilibrium for methanol-acetonitrile-1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4) ternary system was measured at 101.32 kPa using CE-2 Othmer vapor-liquid equilibrium still. UNIFAC equations were used to correlate the experimental data. The experimental results indicated that the vapor-liquid equilibrium curves of the methanol-acetonitrile-. [bmim]BF4 system deviated from that of the [bmim]BF4-free system and the deviation increased with the increase of the [bmim]BF4 dosage. The ionic liquid [bmim]BF4 exhibited notable salt-out effect which could enhance the relative volatility. When the mole fraction of [bmim]BF4 amounted to 10%, the azeotropic point disappeared. UNIFAC equation can be used to predict the equilibrium of methanol-acetonitrile- [bmim]BF4 system.

  12. Phase diagrams and kinetics of solid-liquid phase transitions in crystalline polymer blends

    Science.gov (United States)

    Matkar, Rushikesh A.

    A free energy functional has been formulated based on an order parameter approach to describe the competition between liquid-liquid phase separation and solid-liquid phase separation. In the free energy description, the assumption of complete solvent rejection from the crystalline phase that is inherent in the Flory diluent theory was removed as solvent has been found to reside in the crystalline phase in the form of intercalates. Using this approach, we have calculated various phase diagrams in binary blends of crystalline and amorphous polymers that show upper or lower critical solution temperature. Also, the discrepancy in the chi values obtained from different experimental methods reported in the literature for the polymer blend of poly(vinylidenefluoride) and poly(methylmethacrylate) has been discussed in the context of the present model. Experimental phase diagram for the polymer blend of poly(caprolactone) and polystyrene has also been calculated. Of particular importance is that the crystalline phase concentration as a function of temperature has been calculated using free energy minimization methods instead of assuming it to be pure. In the limit of complete immiscibility of the solvent in the crystalline phase, the Flory diluent theory is recovered. The model is extended to binary crystalline blends and the formation of eutectic, peritectic and azeotrope phase diagrams has been explained on the basis of departure from ideal solid solution behavior. Experimental eutectic phase diagram from literature of a binary blend of crystalline polymer poly(caprolactone) and trioxane were recalculated using the aforementioned approach. Furthermore, simulations on the spatio temporal dynamics of crystallization in blends of crystalline and amorphous polymers were carried out using the Ginzburg-Landau approach. These simulations have provided insight into the distribution of the amorphous polymer in the blends during the crystallization process. The simulated results

  13. Simulation of separation for 2-methoxyethanol-water system by separate heat pump distillation%基于分割式热泵的2-甲氧基乙醇-水精馏工艺模拟

    Institute of Scientific and Technical Information of China (English)

    杨德明; 王杨; 廖巧

    2012-01-01

    Separate heat pump distillation was applied to separate 2-methoxyethanol-water system based on the azeotropic characters of the system. The binary interaction parameters of UNIQUAC equation used for calculating vapor-liquid equilibrium data were fitted against the experimental data of 2-methoxyethanol-water system. Based on the minimum annual operation cost, the simulation and optimization for separate heat pump distillation process were performed by Radfrac block and Compr block in Aspen Plus software, and the optimum conditions were determined, such as the breakpoint mole fraction x(H2O) =0. 17 and the stream input of compressor 6. 16 t/h. The simulation results show that the separate heat pump distillation process can save total annual cost by 34. 4% and the annual operating cost by 36. 3% compared with the conventional heat pump distillation.%基于2-甲氧基乙醇-水体系的共沸特性,应用分割式热泵精馏用于该体系的分离.采用UNIQUAC方程计算该体系的相平衡数据,并利用实验数据对UNIQUAC方程中的二元交互作用参数进行修正.利用Aspen Plus过程模拟软件中的Radfrac精馏模型和Compr等熵压缩模型,以年总费用最小为目标函数,对提出的分割式热泵精馏工艺进行了模拟与优,得到了合适的工艺参数,如分割点摩尔分数为x(H20) =0.17、压缩机进气量为6.16 t/h等关键工艺变量.模拟结果表明,与常规热泵精馏工艺相比,分割式热泵精馏工艺的年总费用可节约34.4%,操作费用可节约36.3%.

  14. 基于双塔精馏的甲醇-碳酸二甲酯分离工艺%Separation technology for methanol-dimethyl carbonate system by double column distillation

    Institute of Scientific and Technical Information of China (English)

    杨德明; 王杨; 廖巧; 张雪杰

    2012-01-01

    Two kinds of double-column distillation process, double effect heat integration distillation and separate heat pump distillation, for separation of methanol-dimethyl carbonate system were simulated based on the methanol-dimethyl carbonate system azeotropic character. The binary interaction parameters of Wilson equation were fitted against the reported experimental data of methanol-dimethyl carbonate system. Based on the minimum annual total cost, simulations for the two kinds of double-column distillation process were performed by Aspen Plus software to achieve the optimal condition. The simulation results showed that the two kinds of double-column distillation need lower energy consumption and less annual total fee. Compared with double effect heat integration distillation, separate heat pump distillation can save total capital fee by 2.69% and annual total fee by 17.33%.%基于甲醇和碳酸二甲酯体系的共沸特性,应用双效热集成和分割式热泵两种双塔精馏工艺进行该体系的分离研究。利用文献报道的实验数据对选用的Wilson物性方程中的二元交互作用参数进行回归修正。利用Aspen Plus模拟软件,以年运行总费用最小为目标函数,分别对提出的两种双塔精馏工艺进行模拟与优化,得到合适的工艺参数。模拟结果表明,两种双塔精馏工艺均比单塔加压精馏工艺其能耗更低、年运行总费用更少。就两种双塔精馏工艺而言,分割式热泵精馏工艺较双效热集成精馏工艺,可节约设备投资费用约2.69%,年运行总费用节约17.33%。

  15. 连钱草挥发油的最佳提取工艺研究%Study on the Extraction Technology of Essential Oils from Glechoma longituba (Nakai) Kupr

    Institute of Scientific and Technical Information of China (English)

    李贵花

    2011-01-01

    [目的]优选采用压力共沸精馏装置提取连钱草挥发油的最佳工艺.[方法]采用正交试验对连钱草挥发油的提取工艺条件进行优选,以挥发油得率为指标,选用L9(34)正交试验表;考察影响挥发油收率的浸泡时间(A)、料液比(B)、提取时间(C)、NaCl浓度(D)4个因素,每个因素取3个水平.[结果]连钱草挥发油的最佳提取工艺为浸泡时间6h,料液比1∶16(g/ml),提取时间4h,NaCl浓度为0;在此条件下连钱草精油的得率为0.03%.[结论]该方法可靠、快捷,准确度高,可用于连钱草挥发油的提取.%[Objective] To confirm the optimum extraction technology of essential oils from Glechoma longituba(Nakai)Kupr on a pressure a-zeotropic distillation device. [Method] Taking the yield of essential oils as index, L9(34) orthogonal lest designed with 4 factors including soa-king time (A) , solid-liquid ratio (B) , extraction time ? and NaCl concentration (D) each of 3 levels was carried out to optimize the extrac-tion technology of essential oils from Gleckoma longituba( Nakai) Kupr. [ Results] The optimum technology for extracting essential oils from Gle-choma longituba(Nakai) Kupr was a combination of 6 h soaking time, 1:16 solid-liquid ratio,4 h extraction time and 0 NaCl concentration,un-der which the yield of essential oils could reach 0.03%. [Conclusion] The method was reliable, rapid and accurate, which could be used to ex-tract essential oils from Glechoma longituba(Nakai)Kupr.

  16. 操作条件对C4醚化产物集成分离的影响%Influence of Operating Conditions on the Hybrid Separation Process Used for C4 Etherified Products

    Institute of Scientific and Technical Information of China (English)

    陆茵; 陈欢林; 张林; 钱志海

    2001-01-01

    The hybrid process of distillation side-connected with pervaporation for the separation of C4 etherified products was simulated with the HYSIM modeling system.A pervaporation unit was used to remove a definite quantity of methanol from the azeotrope of C4 and methanol.The retentate was recycled back to the upper-section of the distillation tower.When a definite quantity of methanol,which was equal to that in the distillation feed was removed by the distillation-side-connected pervaporation unit,and at the meantime the reflux ratio exceeded the critical value,a qualified top product with methanol composition below 1×10-4 was obtained.Both plug-flow and perfect-mixed type pervaporation units have been considered.Simulation results show that the pervaporation unit of plug-flow requires only 64%~90% of membrane area compared to that of perfect-mixed type.If the reserved membrane area is sufficient,the hybrid process can adapt to the composition fluctuation of MTBE reactor effluent.%利用HYSIM软件系统,采用平推流与全混流两种进料方式的渗透汽化工艺,对醚化后C4产物分离的蒸馏-渗透汽化集成过程进行模拟,计算了回流比、侧线出料量、侧线进出口位置、进料及返回液中甲醇含量等操作条件对产物的影响。结果表明,平推流进料所需膜面积仅为全混流的64%~90%。当蒸馏段侧线渗透汽化装置中脱除的甲醇与进料甲醇等量时,塔顶产品不经水洗就可使甲醇摩尔分数降低到1×10-4以下。

  17. Séparations par changement de phase. Etude et représentation des équilibres liquide-vapeur Separation by Phase Hange. Study and Computing Liquid-Vapor Equilibria

    Directory of Open Access Journals (Sweden)

    Asselineau L.

    2006-11-01

    Full Text Available Pour concevoir et optimiser les principales opérations de séparation (particulièrement les distillations avec ou sans solvant et l'extraction liquide-liquide on doit disposer de méthodes de corrélation ou, mieux, de prédiction des équilibres entre phases. A basse pression, et pour les mélanges d'hydrocarbures, les résultats présentés permettent la prévision des coefficients d'équilibre, même pour les séparations les plus délicates. En présence de constituants polaires, les données expérimentales d'équilibre liquide-liquide et liquide-vapeur de mélanges binaires et ternaires peuvent être simultanément corrélées dans le but de simuler et d'optimiser les distillations azéotropiques ou extractives. Sous haute pression, et particulièrement aux abords immédiats du point critique, le choix d'une équation d'état conduit à un traitement unitaire des phases en présence et permet, en particulier, la prédiction du lieu des points critiques des mélanges d'hydrocarbures et la corrélation de ce lieu en présence de solvants polaires. To determine and optimize the main separation operations (in particular distillations with or without a solvent, and liquid-liquid extraction correlation methods must be available or, better yet, methods of predicting phase equilibria. At low pressure and for hydrocarbon mixtures, the results described make the prediction of equilibrium coefficients possible, even for the most delicate separation. In the presence of polar constituents, the experimental data for the liquid-liquid and liquid-vapor equilibrium of binary and ternary mixtures can be simultaneously correlaten so as to simulate and optimize azeotropic or extractive distillations. Under high pressure and especially in the immediate vicinityof the critical point, the choice of an equation of state leads ta a unit treatment of the phases present and, in particular, makes it possible to predict the location of critical points in hydrocarbon

  18. 乙醇胺合成三乙烯二胺工艺的研究%Research for Synthesis of Triethylenedimine from Monoethanolamine

    Institute of Scientific and Technical Information of China (English)

    尚会建; 王少杰; 王丽梅; 郑学明

    2012-01-01

    在自行研制的小型固定床反应器上以乙醇胺为原料进行三乙烯二胺合成工艺的研究,考察了温度、质量空速、氨醇比以及催化剂对反应的影响.研究表明,KCl-Fe2O3-ZSM-5分子筛为最优催化剂,较优的工艺条件为反应温度为375℃、进料质量空速为2.32 h-1、氨醇比为1.6,乙醇胺的转化率可达72.23%,三乙烯二胺的产率达到37.54%,选择性为51.97%;以邻二甲苯作为共沸剂的共沸精馏分离,回流比为5,可以得到纯度为99.31%的三乙烯二胺晶体.%Synthesis process of triethylenediamine from monoethanolamine was studied in a self-developed small fixed bed reactor. The effects of temperature, weight hourly space velocity (WHSV) , the ratio of material and catalyst on reaction were investigated. The results showed that the KCl-Fe2O3-ZSM-5 was the optimum catalyst. The optimum technology conditions were reaction temperature 375 ℃, WHSV 2. 32 h-1 and the ratio of alcohol amine 1.6, the percent conversion of monoethanolamine was up to 72.23% and the yield of triethylenediamine was 37.54% , selection 51. 97%. When the reflux ratio was 5, the purity of TEDA reached 99.31% by azeotropic distillation using 1,2-xylene as the entrainer.

  19. Effect of some degossypolisation treatments of cottonseed meal on its functional properties

    Directory of Open Access Journals (Sweden)

    Mohamed, S. S.

    1993-10-01

    Full Text Available The presence of gossypol is a limiting factor in the use of cottonseed meal for animal feed and human foods. Gossypol in the free form has been found to be toxic to monogastric animals and the Protein Advisor Group of U.N. has limited its content in cottonseed protein products to 0,06%. In the present paper the effect of some degossypolisation techniques on the functional properties of cottonseed meals has been studied. Best results were obtained with the acetic acid method as it improved the nitrogen solubility and available lysine, reduced the free gossypol to 0,03% and enhanced the water absorption capacity, wettability and flowability. The protein product resulting from this treatment can be incorporated into bakery and instant products. The azeotrope: ammonium treatment produced similar effects. Ethanolamine treatment is recommended for the preparation of protein products for instant foods.

    La presencia de gosipol es un factor limitante en el uso de harina de semilla de algodón para la alimentación animal y humana. El gosipol, en forma libre, ha sido encontrado tóxico para animales monogástricos, y el Grupo Asesor en Proteína de Naciones Unidas ha limitado su contenido en productos proteínicos de semilla de algodón al 0,06%. En el presente trabajo se ha estudiado el efecto de algunas técnicas de desgosiposilación sobre las propiedades funcionales de harinas de semillas de algodón. Los mejores resultados se obtuvieron con el método del ácido acético ya que mejoró la solubilidad de nitrógeno y lisina disponible, redujo el gosipol libre al 0,03% y aumentó la capacidad de absorción de agua, humectabilidad y fluidez. El producto proteínico resultante de este tratamiento puede ser incorporado en productos alimenticios instantáneos y horneados. El tratamiento azeótropo: amonio produjo efectos similares. El tratamiento con etanolamina está recomendado para la preparación de productos proteínicos para alimentos instantáneos.

  20. Cycle performance studies on a new HFC-161/125/143a mixture as an alternative refrigerant to R404A

    Institute of Scientific and Technical Information of China (English)

    Xiao-hong HAN; Yu QIU; Ying-jie XU; Men-yuan ZHAO; Qin WANG; Guang-ming CHEN

    2012-01-01

    In this paper,a new ternary non-azeotropic mixture of HFC-161/125/143a (0.15/0.45/0.40 in mass fraction),as a promising mixed refrigerant to R404A,is presented.The ozone depletion potential (ODP) of the new refrigerant is zero and its basic thermodynamic properties are similar to those of R404A,but its global warming potential (GWP) is much smaller than those of R507A and R404A.Meanwhile,theoretical calculations show that,under the working condition Ⅰ (the average evaporation temperature:-23 ℃,the average condensing temperature:43 ℃,the superheat temperature:28 ℃,the subcooling temperature:5 ℃),the volumetric refrigerating effect and specific refrigerating effect of the new mixture are 2.33% and 15.48% higher,respectively,than those of R404A.The coefficient of performance (COP) of the new mixture is 5.19% higher than that of R404A and the pressure ratio of the new mixture is 0.82% lower than that of R404A.Equally,under the working condition Ⅱ (the average evaporation temperature:-40 ℃,the average condensing temperature:35 ℃,the superheating temperature:30 ℃,the subcooling temperature:5 ℃),the volumetric refrigerating effect and specific refrigerating effect of the new mixture are 2.24% and 20.58% higher,respectively,than those of R404A.The COP of the new mixture is 4.60% higher than that of R404A and the pressure ratio of the new mixture is similar to that of R404A.The performances of the new mixture and R404A are compared in a vapor compressor refrigeration apparatus originally designed for R404A under several working conditions (condensing temperatures:35-45 ℃,evaporation temperatures:-40-20 ℃).Experimental results show that the new mixture can obtain a higher COP,by 6.3% to 12.1%,and a lower pressure ratio,by 1.8% to 6.6%,compared to R404A; although the discharge temperature of the new mixture is slightly higher than that of R404A.The advantages of the new mixture will be further verified in the actual system.

  1. 柠檬醛及中间体的合成%Synthesis of Citral and Its Intermediates

    Institute of Scientific and Technical Information of China (English)

    钱洪胜; 董金锋; 吕叔敏; 商志才

    2012-01-01

    Using prenal and prenol as precursors, 3-methyl-2-butenal diprenyl acetal was obtained via an acetalization reaction using senecioic acid as catalyst. Then an elimination of 3-methyl-2-butenal diprenyl acetal catalyzed by ammonium dihydrogen phosphate yielded the cis/trans-prenyl-3-methyl-butadienyl ether. Further rearrangement of the elimination product through heating produced to the target citral. The conditions of acetalization reaction and elimination reaction were optimized. It was found that a conversion yield of 63% ~64% for prenal could be achieved at 70-75℃, for 8 h with 0. 3% senecioic acid as catalyst. After azeotropism treatment, the purity and yield of 3-methyl-2-butenal diprenyl acetal are 97. 5% and 96. 8% , respectively. Using 0. 2% ~0. 5% ammonium dihydrogen phosphate as catalyst, the elimination reaction was carried out at 100 ~ 130 °C and 2. 66 kPa. The cis/irarw-prenyl-3-methylbutadienyl ether was distilled from the reaction batch and its purity and yield are 95. 9% and 97. 0% , respectively. The rearrangement reaction temperature was 120 ~ 130 °C , the purity and yield of citral are 97. 5% and 90. 2% , respectively.%以异戊烯醛和异戊烯醇为原料,经异戊烯酸催化缩醛化反应得到3-甲基-2-丁烯醛二异戊烯基缩醛,再经磷酸二氢铵催化消除反应得到顺/反-异戊二烯基-3-甲基丁二烯醚,并进一步热重排获得柠檬醛.研究了缩醛化反应条件和消除反应条件对转化率的影响.结果表明,以0.3%异戊烯酸为酸性催化剂,70~75℃共沸脱水反应8h,异戊烯醛的单程转化率达到63% ~64%,处理后可得含量为97.5%的3-甲基-2-丁烯醛二异戊烯基缩醛,收率96.8%;以0.2%~0.5%磷酸二氢铵为催化剂,100 ~ 130℃,2.66 kPa下反应并及时将反应产物蒸出,处理后得到含量为95.9%的顺/反-异戊二烯基-3-甲基丁二烯醚,收率97.0%.顺/反-异戊二烯基-3-甲基丁二烯醚在120~130℃重排反应1h,

  2. Preparation of Activated Nano-sized Kaolin Clay as Styrene Butadiene Rubber Filler%应用于橡胶补强的活性纳米高岭土制备

    Institute of Scientific and Technical Information of China (English)

    杜艳艳; 王燕民; 潘志东

    2013-01-01

    An activated nano-sized kaolin clay was prepared via an effective process with various methods such as chemical pre-intercalation, ultra-fine grinding, acid etching, drying and surface modification with cetyltrimethyl ammonium bromide (CTAB) and hydrogen silicone. The results show that the micron-sized kaolin clay that is pre-intercalated with urea is ground in a high-eneigy density stirred bead mill to prepare the nano-sized particles with the fineness of 70% < 100 nm and the lamella thickness of 10-30 nm effectively. This hybrid method could reduce the energy consumption in the preparation of the nano-sized kaolin clay, compared to the single ultra-fine grinding method. The acid etching treatment increased the specific surface area of the activated nano-sized kaolin clay without the destruction of the layered structure. The particles coated with CTAB and hydrogen silicone oil appeared a superior hydrophobicity. The azeotropic distillation drying could produce the well-dispersive activated nano-sized kaolin clay, compared to the spray drying. In addition, the as-prepared activated nano-sized kaolin clay could be used as a styrene butadiene rubber filler to improve the tensile strength and rate, and reduce the vulcanizing time.%采用化学插层-超细研磨-酸侵渍活化-干燥-表面改性的方法有效地制备了活性纳米高岭土.结果表明:通过化学插层与超细研磨的复合方法可制备70%的颗粒小于100 nm的高岭土,其片厚为10~30 nm.与单纯采用机械研磨的方法相比,该复合方法可以降低超细研磨所需的能耗.经酸侵渍活化处理可增大活性纳米高岭土的比表面积,但未破坏高岭土特有的层状结构.在活性纳米高岭土表面包覆十六烷基三甲基溴化铵和含氢硅油,可使其具有良好的亲油疏水性能.另外,对比喷雾干燥方法,经共沸蒸馏干燥的活性纳米高岭土粉体具有更好的分散性,制得的活性纳米高岭土作

  3. 乙醚-甲醇-正丁醇多元系汽液平衡的热力学性质%Thermodynamic Properties for Vapor-Liquid Equilibrium of Diethyl Ether Methanol-n-Butanol Multicomponent System

    Institute of Scientific and Technical Information of China (English)

    高大明; 张凌云; 管航敏; 孙虹; 陈红; 朱德春

    2011-01-01

    Under different liquid phase compositions, the isobaric vapor-liquid equilibrium (VLE) data of three binary systems (diethyl ether-methanol, diethyi ether-n-butanol and methanol-n-butanol) and one ternary system (diethyl ether-methanol-n-butanol) were determined at 101.325 kPa by using a novel pump-ebullionmeter.The vapor-phase compositions y of above three binary systems were calculated from T,p,x by the indirect method.The activity coefficients of the three binary systems were correlated separately with Wilson, N-RTL, Margules and van Laar models, and the parameters of liquid phase activity coefficient models were calculated through the least square method, and then the obtained parameters were used to calculate the vapor-phase compositions y. The obtained activity coefficients were used to calculate the excess Gibbs function (GE/RT) of the three binary systems,and the results show that all the systems studied here do not exhibit azeotropes. Using the obtained parameters of Wilson, NRTL, Margules and van Laar models, the experimental VLE data of the ternary system were correlated to construct the thermodynamic model of VLE for the ternary system and to calculate its equilibrating vapor-phase composition y and the bubble point, respectively. The calculated bubble points agree with the experimental data well, and the thermodynamic consistency of the phase equilibrium data of the three binary systems calculated by those model parameters were checked with area test method and got satisfactory results.%用新型泵式沸点仪测定了在101.325 kPa下乙醚-甲醇、乙醚-正丁醇、甲醇-正丁醇3个二元系以及乙醚-甲醇-正丁醇三元系在不同液相组成时的沸点,并用间接法Tpx推算了3个二元系的汽相平衡组成y.3个二元体系活度系数分别用Wilson模型、NRTL模型、Margules模型和van Laar模型进行关联,用最小二乘法求出了它们的液相活度系数模型参数,同时,用这些模型参数来计算它们的

  4. 木糖醇缩醛类凝胶因子的合成及其凝胶性能%Synthesis of Xylitol Acetal Gelators and the Properties of Gels Prepared from Gelators and Various Solvents

    Institute of Scientific and Technical Information of China (English)

    邓鹏飞; 冯亚青; 宋健

    2011-01-01

    以取代的苯甲醛和木糖醇为原料,环己烷为溶剂和夹带剂,甲醇为促进剂,十二烷基苯磺酸为催化剂,用共沸脱水法合成了5个木糖醇缩醛衍生物:1,3:2,4-二(对甲基苄叉)-D-木糖醇(Ⅰ),1,3:2,4-二(间甲基苄叉)-D-木糖醇(Ⅱ),1,3:2,4-二(邻甲基苄叉)-D-术糖醇(Ⅲ),1,3:2,4-二(3,4一二甲基苄叉)-D-木糖醇(Ⅳ),1,3:2,4-二苄叉-D-木糖醇(Ⅴ).将木糖醇缩醛衍生物用作低相对分子质量(以下简称分子量)有机凝胶因子,比较了其凝胶性能,取代基以空间位阻的形式影响凝胶因子分子的自组装,并能增强凝胶因子分子之间的相互作用.溶剂通过范德华力参与了凝胶三维网络的构建,提高网络的强度.红外光谱测试表明,凝胶形成过程中生成的氢键是该类凝胶因子自组装的驱动力.%Five low molecular-mass organic gelators were synthesized by condensation of xylitol and different derived benzaldehydes using dodecyl benzenesulfonic acid as catalyst and removing water by azeotropic distillation with cyclohexane. They are: 1, 3: 2, 4-O-bis ( 4-methylbenzylidene ) -D-xylitol ( Ⅰ ), 1,3:2,4-O-bis ( 3-methylbenzylidene ) -D-xylitol ( Ⅱ ), 1,3:2,4-O-bis ( 2-methylbenzylidene ) -D-xylitol ( Ⅲ ), 1,3: 2,4-O-bis ( 3,4-dimethylbenzylidene ) -D-xylitol ( Ⅳ ), 1,3: 2,4-O-dibenzylidene-D-xylitol ( Ⅴ ). For the first time xylitol acetal was used as gelator. The performance of gelation was tested using 34 kinds of organic solvents. The substituents of the benzene ring may affect the performance of gellation;some of them can enhance the interaction of the gelator molecular. The solvent molecular participates in the construction of the 3-D network. The infra-red spectrum test indicates that the Hbond generated in the process of producing xylitol acetal gelators provides the propelling force for the self-assembly of such gelators.

  5. CHEMICAL ANALYSIS OF DENSE-GAS EXTRACTS FROM LIME FLOWERS

    Directory of Open Access Journals (Sweden)

    Demyanenko DV

    2015-04-01

    Full Text Available The purpose of this work was to make qualitative and quantitative analysis of phenolic biologically active substances (BAS in the extracts produced from lime flowers with condensed gases, using method of high-performance liquid chromatography (HPLC. Materials and methods: materials for this study were the extracts obtained by consequent processing of the herbal drug and marcs thereof with various condensed gases: difluorochloromethane (Freon R22, difluoromethane (Freon R32, azeotropic mixture of difluoromethane with pentafluoroethane (Freon 410A and freon-ammonium mixture. Extracts obtained with the latter were subjected to further fractionation by liquidliquid separation into hexane, chloroform, ethyl acetate and aqueous-alcohol phases. Besides, the supercritical СО2 extract, obtained from the herbal drug under rather strong conditions (at temperature 60°С and pressure 400 bar, was studied in our previous research. Presence of phenolic BAS and their quantity in the researched samples were determined by method of HPLC with UVspectrometric detection. Results and discussion: It has been found that Freon R22 extracted trace amounts of rutin from lime flowers – its content was only 0.08% of the total extract weight. On the other hand, Freons R32 and R410А showed good selectivity to moderately polar BAS of lime flowers (derivatives of flavonoids and hydroxycinnamic acids: in particular, the extract obtained with freon R32 contained about 1.3% of the total phenolic substances, and it was the only one of the investigated condensed gases used by us which took the basic flavonoid of lime flowers tiliroside – its content was 0.42% of extract weight. Also Freons R32 and R410А were able to withdraw another compound dominating among phenolic substances in the yielded extracts. Its quantity was rather noticeable – up to 0.87% of extract weight. This substance was not identified by existing database, but its UV-spectrum was similar to those of

  6. Pollution control technologies and measures of rare earths hydrometallurgy wastewater%稀土湿法冶炼废水污染治理技术与对策

    Institute of Scientific and Technical Information of China (English)

    陈涛; 李宁; 晏波; 肖贤明

    2014-01-01

    This review paper summarized the source,classification and characteristic of rare earths hydrometallurgy wastewater,and discussed current progresses of the source control,resource recovery and treatment of ammonia nitrogen,fluoride,hydrochloric acid,sulfuric acid and oxalic acid. The findings in this review paper are highlighted as below:a) using fluorine to produce cryolite is an effective method for the fluoride pollution control and resource recovery in the rare earth hydrometallurgy;b) unsaponification process is the trend of the rare earth hydrometallurgy and the recovery of ammonium chloride by the mechanical vapor recompression (MVR) is the optimal process for the treatment of high concentration ammonia ammonium wastewater from the ammonia saponification process;c) the resource recovery of hydrochloric acid and oxalic acid from the oxalic acid precipitation mother liquor by azeotropic distillation has a promising application;d) the process of membrane processing plus MVR evaporation has been shown to be effective in the treatment of low concentrated ammonia nitrogen and other organic pollutants. Possible approaches for the environmental treatment of the rare earths hydrometallurgy wastewater have been also concluded:①improving resources utilization and optimizing process;②separation,recovery,reuse and treatment of wastewater;③developing the process for the advanced treatment and reuse of wastewater.%简述了稀土湿法冶炼废水的来源、分类及污染物特性,重点分析了稀土湿法冶炼废水中氨氮、氟化物、盐酸、硫酸及草酸污染物的源头控制、资源综合利用与环保治理技术现状。结果表明,利用氟生产冰晶石是稀土湿法冶炼过程中氟污染治理和资源回收的有效方法;非皂化工艺是稀土分离工艺的发展方向,采用MVR蒸发工艺回收氯化铵是目前稀土氨皂化废水中高浓度氨氮污染治理的最优工艺;草酸沉淀母液的共沸蒸馏回收盐

  7. Design methodology for integrated downstream separation systems in an ethanol biorefinery

    Science.gov (United States)

    Mohammadzadeh Rohani, Navid

    Energy security and environmental concerns have been the main drivers for a historic shift to biofuel production in transportation fuel industry. Biofuels should not only offer environmental advantages over the petroleum fuels they replace but also should be economically sustainable and viable. The so-called second generation biofuels such as ethanol which is the most produced biofuel are mostly derived from lignocellulosic biomasses. These biofuels are more difficult to produce than the first generation ones mainly due to recalcitrance of the feedstocks in extracting their sugar contents. Costly pre-treatment and fractionation stages are required to break down lignocellulosic feedstocks into their constituent elements. On the other hand the mixture produced in fermentation step in a biorefinery contains very low amount of product which makes the subsequent separation step more difficult and more energy consuming. In an ethanol biorefinery, the dilute fermentation broth requires huge operating cost in downstream separation for recovery of the product in a conventional distillation technique. Moreover, the non-ideal nature of ethanol-water mixture which forms an iseotrope at almost 95 wt%, hinders the attainment of the fuel grade ethanol (99.5 wt%). Therefore, an additional dehydration stage is necessary to purify the ethanol from its azeotropic composition to fuel-grade purity. In order to overcome the constraint pertaining to vapor-liquid equilibrium of ethanol-water separation, several techniques have been investigated and proposed in the industry. These techniques such as membrane-based technologies, extraction and etc. have not only sought to produce a pure fuel-grade ethanol but have also aimed at decreasing the energy consumption of this energy-intensive separation. Decreasing the energy consumption of an ethanol biorefinery is of paramount importance in improving its overall economics and in facilitating the way to displacing petroleum transportation fuel

  8. Quantitative HAZOP analysis of ethylene/ethane hybrid distillationmembrane separation system%乙烯/乙烷精馏-膜耦合分离系统的HAZOP量化分析

    Institute of Scientific and Technical Information of China (English)

    冉慧丽; 肖武; 王明洋; 贺高红

    2012-01-01

    used to separate many industrially important systems. These systems were difficult or impossible to be separated by simple continuous distillation because the phase behavior contains an azeotrope, a tangent pinch, or an overall low relative volatility. But so far HAZOP analysis for the hybrid separation process has rarely been reported. Simulation model of ethylene/ethane hybrid distillation-membrane separation system was built using the Membrane Extension module developed based on UniSim Design software by our research group. Quantitative HAZOP analysis of hybrid distillation-membrane separation system was achieved by combining HAZOP with process simulation. Then effects of different grade deviations of parameters, including feed temperature, feed flow rate and side-draw flow rate of the rectifying column, were investigated. On the basis of simulated results, firstly, deviations used in HAZOP analysis were quantified according to the safety operation scopes of the equipments, then safety thresholds were achieved. Secondly, results of HAZOP analysis were quantified. Reasons of the deviations, consequences of the accident and the severity were analyzed according to the deviation levels. Then the hazard levels were developed. Finally, an analysis report of ethylene/ethane hybrid distillation-membrane separation system was provided based on deviations used in HAZOP analysis and results of HAZOP analysis.