WorldWideScience

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. Microstructures of negative and positive azeotropes.

    Science.gov (United States)

    Shephard, J J; Callear, S K; Imberti, S; Evans, J S O; Salzmann, C G

    2016-07-28

    Azeotropes famously impose fundamental restrictions on distillation processes, yet their special thermodynamic properties make them highly desirable for a diverse range of industrial and technological applications. Using neutron diffraction, we investigate the structures of two prototypical azeotropes, the negative acetone-chloroform and the positive benzene-methanol azeotrope. C-HO hydrogen bonding is the dominating interaction in the negative azeotrope but C-ClO halogen bonding contributes as well. Hydrogen-bonded chains of methanol molecules, which are on average longer than in pure methanol, are the defining structural feature of the positive azeotrope illustrating the fundamentally different local mixing in the two kinds of azeotropes. The emerging trend for both azeotropes is that the more volatile components experience the more pronounced structural changes in their local environments as the azeotropes form. The mixing of the acetone-chloroform azeotrope is essentially random above 20 Å, where the running Kirkwood-Buff integrals of our structural model converge closely to the ones expected from thermodynamic data. The benzene-methanol azeotrope on the other hand displays extended methanol-rich regions and consequently the running Kirkwood-Buff integrals oscillate up to at least 60 Å. Our study provides the first experimental insights into the microstructures of azeotropes and a direct link with their thermodynamic properties. Ultimately, this will provide a route for creating tailored molecular environments in azeotropes to improve and fine-tune their performances. PMID:27367534

  3. 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....

  4. On the Responses of Azeotropes to Pressure Variations

    DEFF Research Database (Denmark)

    Abildskov, Jens; O’Connell, John P.

    2014-01-01

    Systems with azeotropes cannot be separated by simple distillation since the vapor and liquid compositions are the same. Variation of the applied pressure can shift the azeotropic composition out of the range of purification of a single column or may allow pressure swing operation of two columns....... Because of the sensitivity of column size to accurate estimates of the relative volatility, it is important to use reliable phase equilibrium thermodynamics when exploring the possibility of varying pressure to avoid an azeotrope. Based on an analysis of the pressure sensitivity of azeotropic compositions...

  5. Ionic liquids in separations of azeotropic systems – A review

    International Nuclear Information System (INIS)

    Highlights: ► This paper provides a review of methods using ionic liquids as azeotrope breakers. ► Azeotrope breaking potential of ILs was compared to that of conventional solvents. ► The influence of ILs structure on the azeotrope breaking capacity was accomplished. ► Guidelines to select the most suitable ILs as azeotrope breakers were established. - Abstract: Efforts to make existing separation methods more efficient and eco-friendly may get a boost from the use of a relatively new class of compounds known as ionic liquids (ILs). The separation of azeotropic mixtures has conventionally been one of the most challenging tasks in industrial processes due to the fact that their separation by simple distillation is basically impossible. This paper provides a critical review of methods using ILs as azeotrope breakers. Three separation processes were addressed: liquid–liquid extraction, extractive distillation, and supported liquid membranes. We examine the azeotrope breaking potential of ILs and compare their performance to that of conventional solvents. A systematic analysis of the influence of the structure of ILs on their azeotrope breaking capacity contributes to the establishment of guidelines for selecting the most suitable ILs for the separation of specific azeotropic mixtures.

  6. Responses of azeotropes and relative volatilities to pressure variations

    DEFF Research Database (Denmark)

    Abildskov, Jens; O’Connell, John P.

    2015-01-01

    Mixtures with azeotropes cannot be separated by simple distillation since the vapor and liquid compositions are the same. One option to overcome this limitation is to vary the applied pressure to shift the azeotropic composition out of the range of a single column or use pressure-swing operation ...... of mixture excess enthalpies and pure component enthalpies of vaporization....

  7. 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....

  8. Separation of organic azeotropic mixtures by pervaporation

    Energy Technology Data Exchange (ETDEWEB)

    Baker, R.W.

    1991-12-01

    Distillation is a commonly used separation technique in the petroleum refining and chemical processing industries. However, there are a number of potential separations involving azetropic and close-boiling organic mixtures that cannot be separated efficiently by distillation. Pervaporation is a membrane-based process that uses selective permeation through membranes to separate liquid mixtures. Because the separation process is not affected by the relative volatility of the mixture components being separated, pervaporation can be used to separate azetropes and close-boiling mixtures. Our results showed that pervaporation membranes can be used to separate azeotropic mixtures efficiently, a result that is not achievable with simple distillation. The membranes were 5--10 times more permeable to one of the components of the mixture, concentrating it in the permeate stream. For example, the membrane was 10 times more permeable to ethanol than methyl ethyl ketone, producing 60% ethanol permeate from an azeotropic mixture of ethanol and methyl ethyl ketone containing 18% ethanol. For the ethyl acetate/water mixture, the membranes showed a very high selectivity to water (> 300) and the permeate was 50--100 times enriched in water relative to the feed. The membranes had permeate fluxes on the order of 0.1--1 kg/m{sup 2}{center dot}h in the operating range of 55--70{degrees}C. Higher fluxes were obtained by increasing the operating temperature.

  9. 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.

  10. 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

  11. Tissue free water tritium separation from foodstuffs by azeotropic distillation

    International Nuclear Information System (INIS)

    In this paper the tritium separation from tissue free water in foodstuffs by azeotropic distillation is described. Tritium in tissue water is assayed by liquid scintillation counting using well-established quenched correction method. The mean value of the tritium concentration in tissue water from foodstuffs is about 6-12 Bq/l very similar to the tritium mean concentration measured in the surface waters of the area where the samples have been collected (about 12 Bq/l. Therefore, the tritium content in the water fraction of the food samples can be considered in equilibrium with the local environmental water sources. The azeotropic distillation it is an accessible separation method which does not need a sophisticated and expansive distillation apparatus. It is a fast method of separation tissue free water from foodstuffs being very important in the surveillance activity of the environmental within nuclear electric plant. It is suitable for processing a small quantity of samples and for a production type facility when a large number of samples must be processed because the solvent can be purified and reused. The azeotropic distillation has some limits being used to separate water from samples with high content of water (85-90%) and simple a simple chemical structures as: vegetables, fruits, cereal, soil, vegetation. According to the results obtained, the organic substituents of milk, wine, meat (casein, lactose, milk fat, alcohol, esters) may enhance the chemisorption of tritium on through exchange organic hydrogen as -OH, -SH, -NH, -COOH with tritium. Also, the tissue water separation by azeotropic distillation is not complete and can not guarantee the absence of the vaporization isotope effect of the HTO/H2O system., However, the azeotropic distillation is the preferred method of the water extraction from food samples, which makes it useful for the tritium transfer from soil to foodstuffs. (authors)

  12. 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.

  13. The effect of azeotropism on combustion characteristics of blended fuel pool fire.

    Science.gov (United States)

    Ding, Yanming; Wang, Changjian; Lu, Shouxiang

    2014-04-30

    The effect of azeotropism on combustion characteristics of blended fuel pool fire was experimentally studied in an open fire test space of State Key Laboratory of Fire Science. A 30 cm × 30 cm square pool filled with n-heptane and ethanol blended fuel was employed. Flame images, burning rate and temperature distribution were collected and recorded in the whole combustion process. Results show that azeotropism obviously dominates the combustion behavior of n-heptane/ethanol blended fuel pool fire. The combustion process after ignition exhibits four typical stages: initial development, azeotropic burning, single-component burning and decay stage. Azeotropism appears when temperature of fuel surface reaches azeotropic point and blended fuel burns at azeotropic ratio. Compared with individual pure fuel, the effect of azeotropism on main fire parameters, such as flame height, burning rate, flame puffing frequency and centerline temperature were analyzed. Burning rate and centerline temperature of blended fuel are higher than that of individual pure fuel respectively at azeotropic burning stage, and flame puffing frequency follows the empirical formula between Strouhal and Froude number for pure fuel. PMID:24632362

  14. Separation of organic azeotropic mixtures by pervaporation. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Baker, R.W.

    1991-12-01

    Distillation is a commonly used separation technique in the petroleum refining and chemical processing industries. However, there are a number of potential separations involving azetropic and close-boiling organic mixtures that cannot be separated efficiently by distillation. Pervaporation is a membrane-based process that uses selective permeation through membranes to separate liquid mixtures. Because the separation process is not affected by the relative volatility of the mixture components being separated, pervaporation can be used to separate azetropes and close-boiling mixtures. Our results showed that pervaporation membranes can be used to separate azeotropic mixtures efficiently, a result that is not achievable with simple distillation. The membranes were 5--10 times more permeable to one of the components of the mixture, concentrating it in the permeate stream. For example, the membrane was 10 times more permeable to ethanol than methyl ethyl ketone, producing 60% ethanol permeate from an azeotropic mixture of ethanol and methyl ethyl ketone containing 18% ethanol. For the ethyl acetate/water mixture, the membranes showed a very high selectivity to water (> 300) and the permeate was 50--100 times enriched in water relative to the feed. The membranes had permeate fluxes on the order of 0.1--1 kg/m{sup 2}{center_dot}h in the operating range of 55--70{degrees}C. Higher fluxes were obtained by increasing the operating temperature.

  15. 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.

  16. 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.

  17. Interference phenomena in azeotropic distillation for liquid scintillation measurement

    International Nuclear Information System (INIS)

    Full text: The Cryogenic Pilot is an experimental project within the National Nuclear Energy Research Program, which aims at developing technologies for tritium and deuterium separation by cryogenic distillation. The process used in this installation is based on a combined method for liquid-phase catalytic exchange (LPCE) and cryogenic distillation. There are two ways in which the Cryogenic Pilot can interact with the environment: by atmospheric release and through the sewage system. In order to establish the base concentration level of thr tritium released in the environment around the nuclear facilities, we investigated the sample preparation treatment for different types of samples: spinach, spring wheat, onion, hay, grass, apple, garden lettuce, soil, milk, and meat. For the azeotropic distillation of all types of samples were used two solvents, toluene and cyclohexane, and all measurements for the determination of environmental tritium concentration were carried out using liquid scintillation counting (LSC), with ultra-low liquid scintillation spectrometer Quantulus 1220 specially designed for environmental samples and low radioactivity. Sample scintillation cocktail ratio was 8:12 ml and liquid scintillation cocktail was UltimaGold LLT. The background determined for the prepared control samples was between 0.926 CPM and 1.002 CPM and the counting efficiency between 25.4% and 26.1%. The counting time was 1000 minutes (50 minutes/20 cycles) for each sample, and the minimum detectable activity according to ISO 9698 was 8.9 TU, and 9.05 TU, respectively, with a confidence factor of 3. (authors)

  18. A PROCESS FOR SEPARATING AZEOTROPIC MIXTURES BY EXTRACTIVE AND CONVECTIVE DISTILLATION

    Science.gov (United States)

    Frazer, J.W.

    1961-12-19

    A method is described for separating an azeotrope of carbon tetrachloride and 1,1,2,2-tetrafluorodinitroethane boiling at 60 deg C. The ndethod comnprises, specifically, feeding azeotrope vapors admixed with a non- reactive gas into an extractive distillation column heated to a temperature preferably somewhat above the boiling point of the constant boiling mixture. A solvent, di-n-butylphthalate, is metered into the column above the gas inlet and permitted to flow downward, earrying with it the higher bomling fraction, while the constituent having the lower boiling point passes out of the top of the column with the non-reactive gas and is collected in a nitrogen cold trap. Other solvents which alter the vapor pressure relationship may be substituted. The method is generally applicable to azeotropic mixtures. A number of specific mixtures whicb may be separated are disclosed. (AEC)

  19. 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

    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...... design (CAMD) method and the UNIFAC-IL model is used to screen design candidates based on minimum ionic liquid concentration needed to break the azeotrope. Once the ionic liquid has been designed, the extractive distillation column for the azeotropic mixture is designed using the driving force method...... with a new proposed feed stage scaling to minimize energy inputs. Along with the distillation column, an ionic liquid recovery stage is designed and simulations are used to determine the overall heat duty for the entire process for the best ionic liquid candidates. Use of a designed ionic liquid reduces...

  20. Investigation on incomplete condensation of non-azeotropic working fluids in high temperature heat pumps

    International Nuclear Information System (INIS)

    In order to improve high temperature heat pumps (HTHP), firstly, after theoretical analysis is conducted about the heat transfer of non-azeotropic working fluids in the condenser, the possibility of incomplete condensation of non-azeotropic working fluids in the condenser of a HTHP is presented. Secondly, an experimental plan is designed to study the phenomenon, and many working conditions experiments (flow rate, temperature and frequency are changed) are done on a water-to-water heat pump unit. Finally, the incomplete condensation is found, and some relationships are presented between the phenomenon and the parameters, which are helpful to improve the control strategy of the HTHP

  1. Behavior of the Thermodynamic Properties of Binary Mixtures near the Critical Azeotrope

    Directory of Open Access Journals (Sweden)

    Azzedine Abbaci

    2003-12-01

    Full Text Available Abstract: In this work we investigate the critical line of binary azeotropic mixtures of acetone-n-pentane. We pinpoint the abnormal behavior of the critical density line as a function of the mole fraction of one of the component and show its influence on other thermodynamic properties such as the volume, the enthalpy and the entropy.

  2. 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.

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

    DEFF Research Database (Denmark)

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

    environmental impact would they cause? Ionic liquids show great promise for solvent-based separation, particularly for extractive distillation-based separations, due to their negligible vapor pressures and the fact that a wide range of solubilities and other properties can be obtained through structural changes....... Since a large number of azeotropes encountered include water as one of the compounds, the use of ionic liquids in solvent-based separation of water in azeotropic systems has been investigated. Along with the design of the ionic liquid being used to entrain water, the extractive distillation process has...... also designed as an integrated ionic liquid –extractive process design. Based on the separation desired (for example, remove the water), an ionic liquid solvent and the separation process is designed or selected from a library of designed solutions, based upon the methodology that has been developed...

  4. 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

  5. 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.)

  6. 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.

  7. Azeotropic distillation in a middle vessel batch column. 3: Model validation

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, W.; Barton, P.I. [Massachusetts Inst. of Tech., Cambridge, MA (United States)

    1999-04-01

    A dimensional time model of the middle vessel batch distillation column (MVC) is developed in the ABACUSS process modeling environment, and simulations are conducted to validate the theoretical insights developed for the operation of the MVC based on a warped time model of the MVC. The qualitative dynamics of the MVC operated in the presence of linear separation boundaries are validated via simulations conducted on the ternary azeotropic mixture of acetone, chloroform, and methanol. It is also shown via simulation that the separation results obtained from a column with significant but reasonable amounts of holdup on the trays are not significantly different from a column in which holdup in the trays is assumed to be negligible. Theoretical operating policies for separating the azeotrope of acetone and chloroform using benzene as a batch entrainer are also validated using the ABACUSS model. Finally, the authors explore the advantages and disadvantages of different feasible operating policies for separating a mixture of acetone, benzene, and chloroform completely into its constituent pure components.

  8. An Analytical Method to Measure Free-Water Tritium in Foods using Azeotropic Distillation.

    Science.gov (United States)

    Soga, Keisuke; Kamei, Toshiyuki; Hachisuka, Akiko; Nishimaki-Mogami, Tomoko

    2016-01-01

    A series of accidents at the Fukushima Dai-ichi Nuclear Power Plant has raised concerns about the discharge of contaminated water containing tritium ((3)H) from the nuclear power plant into the environment and into foods. In this study, we explored convenient analytical methods to measure free-water (3)H in foods using a liquid scintillation counting and azeotropic distillation method. The detection limit was 10 Bq/L, corresponding to about 0.01% of 1 mSv/year. The (3)H recoveries were 85-90% in fruits, vegetables, meats and fishes, 75-85% in rice and cereal crops, and less than 50% in sweets containing little water. We found that, in the case of sweets, adding water to the sample before the azeotropic distillation increased the recovery and precision. Then, the recoveries reached more than 75% and RSD was less than 10% in all food categories (13 kinds). Considering its sensitivity, precision and simplicity, this method is practical and useful for (3)H analysis in various foods, and should be suitable for the safety assessment of foods. In addition, we examined the level of (3)H in foods on the Japanese market. No (3)H radioactivity was detected in any of 42 analyzed foods. PMID:27558225

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Phosphoric-based ionic liquids as solvents to separate the azeotropic mixture of ethanol and hexane

    International Nuclear Information System (INIS)

    Graphical abstract: Potential solvent for the separation of ethanol and hexane in (liquid + liquid) extraction. - Highlights: • Phosphoric-based ILs were studied as solvents to extract ethanol from hexane. • LLE data for ternary systems with miscibility gap were presented. • The NRTL model can correlate the experimental LLE data with a good accuracy. • [MMIM][DMP] was a promising solvent for the separation of ethanol and hexane. - Abstract: Ethanol and hexane mixtures are present in industrial processes producing oxygenated additives for unleaded gasoline. The separation of ethanol and hexane is important but challenging due to the formation of an azeotropic mixture. This research focuses on the study of phosphoric-based ionic liquids (ILs) as green solvents for the separation of ethanol from hexane in a liquid extraction process. The knowledge of the (liquid + liquid) equilibrium (LLE) of this mixture is essential for the design of the extraction separation technique. Hence, the experimental determination of the LLE data for the ternary system {ethanol + hexane + 1,3-dimethylimidazolium dimethylphosphate ([MMIM][DMP])}, {ethanol + hexane + 1-ethyl-3-methylimidazolium diethylphosphate ([EMIM][DEP])} and {ethanol + hexane + 1-butyl-3-methylimidazolium dibutylphosphate ([BMIM][DBP])} at T = 303.2 K and atmospheric pressure was carried out. The reliability of the experimental LLE data was confirmed by applying the Othmer–Tobias and Hand equations, and the NRTL model was used to correlate the experimental results for the studied ternary system. The solute distribution ratio and selectivity, derived from the experimental LLE data, were calculated and analyzed evaluate the capacity of the investigated ILs as solvents in liquid extraction process. This capacity was also compared with that of other ILs. The experimental results show that the studied ILs can be suitable solvents in a (liquid + liquid) extraction for the separation of azeotropic mixtures of ethanol

  15. 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 ℃.

  16. 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.

  17. Observation of vapor bubble of non-azeotropic binary mixture in microgravity with a two-wavelength interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Yoshiyuki; Iwasaki, Akira

    1999-07-01

    Although non-azeotropic mixtures are considered to be promising working fluids in advanced energy conversion systems, the primary technical problems in the heat transfer degradation in phase change processes cause economical handicap to wide-spread applications. The boiling behavior of mixtures still remains a number of basic questions being not answered yet, and the present authors believe that the most essential information for the boiling process in non-azeotropic mixtures is how temperature and concentration profiles are developed around the bubbles. The present study attempts at understanding fundamental heat and mass transfer mechanisms in nucleate pool boiling of non-azeotropic binary mixtures, and with the knowledge to develop a passive boiling heat transfer enhancement eventually. To this end, the authors have employed microgravity environment for rather detailed observation around vapor bubbles in the course of boiling inception and bubble growth. A two-wavelength Mach-Zehnder interferometer has been developed, which withstands mechanical shock caused by gravity change from very low gravity of the order of 10{sup {minus}5} g to relatively high gravity of approximately 8 g exposed during deceleration period. A series of experiments on single vapor bubbles for CFC113 single component and CFC12/CFC112 non-azeotropic binary mixture have been conducted under a high quality microgravity conditions available in 10-second free-fall facility of Japan Microgravity Center (JAMIC). The results for single component liquid showed a strong influence due to Marangoni effect caused by the temperature profile around the bubble. The results for non-azeotropic binary mixture showed, however, considerably different behavior from single component liquid. Both temperature and concentration profiles around a single vapor bubble were evaluated from the interferograms. The temperature and concentration layers established around the bubbles were nearly one order of magnitude larger

  18. 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.

  19. Ethanol extraction from its azeotropic mixture with hexane employing different ionic liquids as solvents

    International Nuclear Information System (INIS)

    Highlights: ► Several ionic liquids were investigated as solvents to extract ethanol from hexane. ► Determination of LLE for the ternary systems was carried out at T = 298.15 K. ► Structural influence of the ionic liquids on the extraction process was analyzed. ► Experimental LLE data were correlated by means of the NRTL and UNIQUAC models. - Abstract: In this work, the ionic liquids 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [EMim][NTf2], 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [BMim][NTf2], 1-butyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide, [BMpy][NTf2], 1-butyl-3-methylpyridinium trifluoromethanesulfonate, [BMpy][TfO], have been investigated for their use as solvents in extraction processes for the ethanol removal from its azeotropic mixture with hexane. Therefore, the experimental determination of the liquid + liquid equilibrium for the ternary systems {hexane (1) + ethanol (2) + [EMim][NTf2] (3)}, {hexane (1) + ethanol (2) + [BMim][NTf2] (3)}, {hexane (1) + ethanol (2) + [BMpy][NTf2] (3)} and {hexane (1) + ethanol (2) + [BMpy][TfO] (3)} was carried out at T = 298.15 K and atmospheric pressure. Classical parameters such as selectivity and solute distribution ratio, derived from the tie-line data, were calculated and afterwards, the structural influence of the ionic liquids on the extraction process was analyzed. Finally, the experimental LLE data were correlated by means of the NRTL and UNIQUAC models.

  20. Synthesis of γ-Al2O3 with High Surface Area and Large Pore Volume by Reverse Precipitation-azeotropic Distillation Method

    Institute of Scientific and Technical Information of China (English)

    WU Yu-sheng; MA Jiao; LI Ming-chun; HU Fang

    2013-01-01

    γ-A12O3 with high surface area and large pore volume combined with high thermal stability was synthesized by a reverse precipitation-azeotropic distillation method.The effects of azeotropic distillation on the characteristics of γ-A12O3 were studied by means of X-ray diffraction(XRD),Fourier transform infrared(FTIR) spectroscopy,transmission electron microscopy(TEM) and N2 adsorption-desorption.The results show that γ-A12O3 dried by azeotropic distillation has excellent structure characteristics with a high surface area of 426 m2/g and a large pore volume of 2.56 cm3/g.After calcination at 1100 C,the surface area of γ-A12O3 was still 92 m2/g with a large pore volume of 1.00 cm3/g,indicating the potential application in catalyst and petroleum industry.

  1. 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

    2016-07-01

    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.

  2. 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...

  3. 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

  4. 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

  5. PREPARATION OF NANOMETER ZrO2-8%Y2O3 POWDERS BY AZEOTROPIC DISTILLATION PROCESSING

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Gels of Zr(OH)4 and Y(OH)3, prepared by the chemical coprecipitation method, were effec tively dehydrated by the azeotropic distillation processing. Because of the removal of interparticle free water,replacement of surface hydroxyl groups with butoxy groups and steric effects of n-butanol, colse approach of gel particles and Zr-O-Zr chemical bond formation between them were prevented. Nanometer ZrO2-8 % (mole fraction, % )Y2O3 powders prepared by this processing, with the average particle size of 16 nm, can be sintered to 98.5 % TD at 1450 ℃ for 2 h with an average grain size of ceramic of 0.3 μm.

  6. 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.

  7. Water content of pyrolysis oil: Comparison between Karl Fischer titration, GC/MS-corrected azeotropic distillation and H-1 NMR spectroscopy

    OpenAIRE

    Smets, Koen; Adriaensens, Peter; VANDEWIJNGAARDEN, Jens; STALS, Mark; Cornelissen, Tom; Schreurs, Sonja; Carleer, Robert; Yperman, Jan

    2011-01-01

    Pyrolysis converts biomass waste mainly into pyrolysis oil, which is a possible source of renewable energy and/or value-added chemicals. A very important characteristic of pyrolysis oil is its water content. Karl Fischer titration and azeotropic distillation by the Dean-Stark method are two common techniques for water determination. In this study, the water content is determined for several pyrolysis oil samples with a wide range in water content and/or originating from different types of bio...

  8. 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.

  9. Use of azeotropic distillation for isotopic analysis of deuterium in soil water and saturate saline solution; Emprego da destilacao azeotropica para analise isotopica do deuterio em agua do solo e solucao salina saturada

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Antonio Vieira dos

    1995-05-01

    The azeotropic distillation technique was adapted to extract soil water and saturate saline solution, which is similar to the sea water for the Isotopic Determination of Deuterium (D). A soil test was used to determine the precision and the nature of the methodology to extract soil water for stable isotopic analysis, using the azeotropic distillation and comparing with traditional methodology of heating under vacuum. This methodology has been very useful for several kinds of soil or saturate saline solution. The apparatus does not have a memory effect, and the chemical reagents do not affect the isotopic composition of soil water. (author). 43 refs., 10 figs., 12 tabs.

  10. Azeotropic Pressure Swing Distillation

    OpenAIRE

    Klein, Andreas

    2008-01-01

    Ziel der vorliegenden Arbeit ist die Analyse, Bewertung und der Vergleich des kontinuierlichen und der diskontinuierlichen (Batch) Zweidruck-Destillations-Prozesse. Hierzu wurde ein rigoroses dynamisches Modell entwickelt, welches den Anfahrvorgang der Kolonnen aus kaltem und leerem Zustand für beide Prozesse berücksichtigt. Für den kontinuierlichen Prozess wurde die Wärmeintegration analysiert. Hier sind Energieeinsparungen von bis zu 45% möglich. Mit Hilfe des Modells wurden unterschiedlich...

  11. 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.

  12. Cálculo y Predicción de Azeótropos Multicomponentes con Modelos de Coeficientes de Actividad Calculation and Prediction of Multicomponent Azeotropes with Activity Coefficient Models

    Directory of Open Access Journals (Sweden)

    Beatriz A Mandagarán

    2008-01-01

    Full Text Available Se estudia la capacidad predictiva de azeótropos multicomponentes con modelos de coeficiente de actividad. Para los azeótropos homogéneos se utilizan Wilson y UNIFAC y para los azeótropos heterogéneos se utilizan UNIQUAC y UNIFAC. Los cálculos se realizan con el software comercial DISTIL y HYSYS con los parámetros binarios de la base de DISTIL ó en su defecto estimados a partir de información experimental de los binarios. Los resultados del trabajo indican que la capacidad predictiva de los modelos disminuye al aumentar el número de componentes de la mezcla. La predicción es buena para azeótropos ternarios y regular para azeótropos de 4 y 5 componentes, tanto para Wilson como para UNIQUAC. Las predicciones con UNIFAC son comparables a los cálculos con los otros modelos pero introducen inmiscibilidad de fases en algunos sistemas homogéneos.This paper studies the multicomponent azeotropic capacity prediction of activity coefficient models. Wilson and UNIFAC models are used for homogeneous azeotropes while UNIQUAC and UNIFAC models are used for heterogeneous azeotropes. Calculations were done with the commercial software DISTIL and HYSYS using the DISTIL Data Base for the binary parameters. In the case that binary parameters were not available they were estimated from binary experimental data. The prediction capability of the models decreases as the number of components in the mixtures increases. Prediction from Wilson and UNIQUAC are good for ternaries and poor for 4 and 5 component mixtures. Prediction using UNIFAC is as good as those from Wilson and UNIQUAC. However, calculations with UNIFAC produce occasionally two liquid phases in homogeneous systems.

  13. Synthesis of CeO2 Nanoparticles by Azeotropic Distillation Processing%共沸蒸馏法合成CeO2纳米颗粒研究

    Institute of Scientific and Technical Information of China (English)

    宋晓岚; 何希; 曲鹏; 江楠; 邱冠周

    2008-01-01

    分别以乙醇、正丙醇、异丙醇、正丁醇、异丁醇、仲丁醇及叔丁醇等七种有机醇作为共沸剂,采用液相沉淀法结合共沸蒸馏处理前驱体成功合成了分散性良好、粒子尺寸分布为10~20nm的纳米CeO2颗粒,运用TG/DTA、FIIR、XRD、TEM等方法对不同有机醇的共沸蒸馏作用以及产品性能进行了分析和表征,探讨了共沸蒸馏法制备纳米CeO2的机理.结果表明:共沸蒸馏能起到有效脱除前驱体凝胶中的水分,防止其干燥和焙烧过程中的硬团聚形成的作用,其中七种醇中以正丁醇的共沸蒸馏效果最佳,所得纳米CeO2颗粒的粒度、均匀及分散性能最好.%CeO2 nanoparticles were synthesized by precipitation method.The azeotropic distillation technique was carried out to dehydrate hydrous gels and ensure complete elimination of the residual water in the precursors.The effects of seven different alcohols(ethanol,n-propyl alcohol,isopropanol,n-butyl alcohol,isobutanol,secondary butyl alcohol,tert-butyl alcohol)as entrainer were compared with each other.DSC(different scanning calorimetry)/TG(thermalgravimetric),FI-IR(Infra-red spectrum analysis),XRD(X-ray diffraction)and TEM(transmission electron spectroscopy)were performed to characterize the structures and properties of CeO2 nanoparticles.Among seven alcahols,n-butyl aleohol has the best effect during azeotropic distillation.After azeotropic distillation with n-butyl alcohol,particles with well dispersity and an average size of 10~20nm were obtained.The azeotropic distillation processing Was proved to be quite effective in reduced the possibility of the formation of chemical bonds and prevented the formation of hard agglomerates.

  14. 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.

  15. 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.

  16. Effect of methylimidazolium-based ionic liquids on vapor-liquid equilibrium behavior of tert-butyl alcohol+water azeotropic mixture at 101.3 kPa☆

    Institute of Scientific and Technical Information of China (English)

    Zhigang Zhang; Qiang Zhang; Tao Zhang; Qinqin Zhang; Wenxiu Li

    2016-01-01

    Three ionic liquids (ILs), 1-ethyl-3-methylimidazolium bromine ([EMIM]Br), 1-butyl-3-methylimidazolium bro-mine ([BMIM]Br), and 1-hexyl-3-methylimidazolium bromine ([HMIM]Br), were used as the solvent for separa-tion of{tert-butyl alcohol (TBA)+water}azeotrope. Vapor–liquid equilibrium (VLE) data for{TBA+water+IL}ternary systems were measured at 101.3 kPa. The results indicate that al the three ILs produce an obvious effect on the VLE behavior of{TBA+water}system and eliminate the azeotropy in the whole concentration range. [EMIM]Br is the best solvent for the separation of{TBA+water}system by extractive distil ation among the three ILs. The experimental VLE data for the ternary systems are correlated with the NRTL model equation with good correlations. Explanations are given with activity coefficients of water and TBA, and the experimental VLE-temperature data for{TBA or water+IL}binary systems.

  17. 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.

  18. 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%.

  19. 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.

  20. 三元共沸物法提纯米糠蜡工艺条件的优化%The optimization of process conditions for ternary azeotrope to extract rice bran wax

    Institute of Scientific and Technical Information of China (English)

    张根生; 王洪娟; 张明刚; 艾晓丽; 刘琼

    2011-01-01

    Chose wax paste of rice bran oil processing by-products as raw materials,ethyl acetate-ethanol-water ternary azeotrope as solvent,extraction yield and acetone insoluble(purity)as index,after get rice bran wax by process of extraction[solvent∶ raw materials(v∶ m),6∶ 1],centrifugal separation,rotating evaporation,low temperature drying.Rice bran wax extraction process condition was optimized through the response surface method.Results showed the best extraction condition was∶ solvent than was 6∶ 1,extraction temperature 65℃,45min for extraction time,cooling temperature was 20℃.At this time,model predicts extraction rate of rice bran wax was 89.65%,acetone insoluble was 64.30%,verifying test for extraction of rice bran wax was 89.17%,acetone insoluble was 63.67%,and basically consistent with the predicted value.%以米糠油加工的副产物蜡糊为原料,乙酸乙酯-乙醇-水三元共沸物为溶剂,以提取率和丙酮不溶物(纯度)为指标,经萃取[溶剂∶原料(v∶m),6∶1]、离心分离、旋转蒸发、低温干燥制得米糠蜡;通过响应曲面法优化米糠蜡提取工艺条件。结果表明,最佳提纯条件为:料液比6∶1,提取温度65℃,提取时间45min,冷却温度20℃,此时,模型预测米糠蜡提取率为89.65%,丙酮不溶物为64.30%。验证实验得米糠蜡提取率为89.17%,丙酮不溶物为63.67%,与预测值基本吻合。

  1. 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.

  2. 不饱和聚酯树脂高浓度废水共沸精馏资源化与治理技术%Recycling by azeotropic distillation and treatment technologies for high concentration wastewater from unsaturated polyester resin process

    Institute of Scientific and Technical Information of China (English)

    赵贤广; 李武; 朱明新; 徐炎华; 许培圣; 盛建凯; 马越群; 沈洪; 朱锐

    2011-01-01

    Aiming at the characteristics of high concentration wastewater from unsaturated polyester resin process, a novel azeotropic distillation was adopted as a recycling pretreatment. The experimental results showed that by the azeotropic distillation, the organic compounds in the wastewater, such as raw materials, polymeriza- tion intermediate etc, were almost condensed in the tower bottom liquid with COD up to 1 200 000 mg/L, and the total recovery rate of the organic compounds was about 93% -96%. Feeding the condensed liquid with COD 1 200 000 mg/L into the unsaturated polyester resin synthesis in 20% ratio to another raw materials, a new un- saturated polyester resin with better performances was attained, and the yielding rate increased from 93.4% in traditional process to 99.77%. For the distilled wastewater with COD about 10 000 mg/L separated from the en- trainer, a multi-technology enhanced catalytic oxidation technique was employed as pretreatment, resulting in the wastewater B/C increase from 0. 021 to above 0.3. The pretreated wastewater was treated again with biochemical treatment by EGSB + MBBR technology and advanced treatment by activated carbon adsorption technology. E- ventually, the quality of effluent water could meet the state' s discharge standard and the cooling water standard.%针对不饱和聚酯树脂生产高浓度废水的特点,采用新型共沸精馏技术进行资源化预处理。实验结果表明,共沸精馏几乎将废水中的原料、聚合中间体等有机物全部浓缩于釜液中,釜底浓缩液COD可高达120万mg/L左右,有机物回收率达93%~96%。将COD约120万nq-g/L的釜液以20%比例投入不饱和聚酯树脂合成反应中,制得了一种新型高性能树脂,且树脂的得率由常规生产的93.4%提高至99.77%。对与共沸剂分离后的COD约为1万mg/L的馏出液采用新型多技术协同催化氧化技术进行预处理,使废水B/C由0.021提高至0.3以

  3. 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 .

  4. 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.

  5. 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...

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

    OpenAIRE

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

    2010-01-01

    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 x1 = 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 x1 < 0.90, the enthalpy ...

  7. 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.

  8. Flow boiling heat transfer of a non-azeotropic mixture inside a single microchannel

    OpenAIRE

    Del Col, D; Azzolin, M; Bortolin, S; 4th Micro and Nano Flows Conference (MNF2014)

    2014-01-01

    This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, U...

  9. 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.

  10. R–502 and Two Near-Azeotropic Alternatives. Part II: Two-Phase Flow Patterns.

    OpenAIRE

    Kattan, Nakhlé; Favrat, Daniel; Thome, John R.

    1995-01-01

    Flow patterns for horizontal intube flow boiling have been studied for the new refrigerants HP80 and HP62 and the conventional refrigerant R-502. The flow pattern observations were compared with several criteria utilized in horizontal flow boiling correlations for determining whether the entire circumference of a horizontal evaporator tube is all wet or only partially wet. Use of only the liquid Froude number FrL (utilized by numerous flow boiling correlations) is shown to b...

  11. 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......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...

  12. 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.

  13. 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

  14. Actual inevitable exergy loss in vapor-compression refrigeration cycle with non-azeotropic refrigerant mixtures%非共沸混合工质压缩制冷循环的不可避免(火用)损失

    Institute of Scientific and Technical Information of China (English)

    肖跃雷; 傅秦生; 冯霄; 鲁立平

    2003-01-01

    以非共沸混合工质替代CFCs是比较有效的替代方案.通过对给定节点温差下的蒸发器和冷凝器内的温度匹配分析,提出利用调节非共沸混合工质的配比来优化蒸发器和冷凝器内的温度匹配,并可计算出循环的实际不可避免(火用)损失,从而提出采用非共沸混合工质的蒸气压缩制冷循环的实际不可避免(火用)损失的计算方法,并提出利用最佳配比和实际不可避免的(火用)损失的计算,对各种非共沸混合工质对进行筛选,以进一步减少循环可避免的(火用)损失,为优化蒸气压缩制冷循环,提高循环的性能奠定基础.

  15. Feasibility of extractive distillation process variants in batch rectifier column

    OpenAIRE

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

    2005-01-01

    A systematic comparison is presented about the separation tasks of azeotropic and close-boiling mixtures applying batch extractive distillation (BED) in rectifier. All the eight possible mixture types with at most a single azeotrope (minimum and maximum boiling azeotropes with heavy, light, and intermediate boiling entrainers; and close boiling mixtures with heavy and light entrainers) are compared. The main results of the feasibility studies on the hitherto unpublished cases are presented. A...

  16. Volume reduction and encapsulation process for water containing low level radioactive waste

    International Nuclear Information System (INIS)

    In encapsulating solutions or slurries of radio-active waste within polymeric material for disposal, the water is removed therefrom by adding a water insoluble liquid forming a low boiling azeotrope and evaporating the azeotrope, and then a polymerisable composition is dispersed throughout the dewatered waste and allowed to set. (author)

  17. 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.

  18. Vapor-Liquid Equilibrium for Binary Mixtures of 1,4-Diazabicyclo[2.2.2]octane with Ethylenediamine, Ethanolamine, and Ethylene Glycol

    Science.gov (United States)

    Trejbal, Jiří

    2009-04-01

    Vapor-liquid equilibria of mixtures of 1,4-diazabicyclo[2.2.2]octane with ethylenediamine, ethanolamine, and ethylene glycol were studied. Ideal behavior in the ethylenediamine and 1,4-diazabicyclo[2.2.2]octane mixture was observed. Ethanolamine and 1,4-diazabicyclo[2.2.2]octane form an azeotrope with a minimum boiling point whereas ethylene glycol and 1,4-diazabicyclo[2.2.2]octane form an azeotrope with a maximum boiling point. Non-ideal behavior of the mixtures was described by the NRTL equation, and the corresponding constants were calculated.

  19. Vapor-liquid equilibria for acetone + chloroform + methanol and constituent binary systems at 101. 3 kPa

    Energy Technology Data Exchange (ETDEWEB)

    Hiaki, Toshihiko (Nihon Univ., Chiba (Japan). Dept. of Industrial Chemistry); Kurihara, Kiyofumi; Kojima, Kazuo (Nihon Univ., Tokyo (Japan). Dept. of Industrial Chemistry)

    1994-10-01

    Vapor-liquid equilibria (VLE) and azeotropic data, which are useful for the design and operation of separation processes, have been observed for many systems. Isobaric vapor-liquid equilibria for acetone + chloroform + methanol and for the constituent binary systems chloroform + methanol and chloroform + acetone were measured at 101.3 kPa using a liquid-vapor ebullition-type equilibrium still. The experimental data were correlated with the extended Redlich-Kister and Wilson equations. The data were best correlated and completely calculated for the ternary and three binary azeotropic data using the extended Redlich-Kister equation.

  20. Fluid Phase Topology of Benzene + Cyclohexane + 1-Propanol at 101.3 kPa

    Science.gov (United States)

    Andrade, R. S.; Iglesias, M.

    2015-07-01

    Isobaric vapor-liquid equilibria for the benzene + cyclohexane + 1-propanol ternary mixture were experimentally investigated at atmospheric pressure. Data were tested and considered thermodynamically consistent by means of the McDermott and Ellis method. The experimental results showed that this ternary mixture is completely miscible and exhibits three binary minimum homogeneous azeotropes and a ternary minimum azeotrope at the studied conditions. Satisfactory results were obtained for correlation of equilibrium compositions with the UNIQUAC equation and also for prediction with the UNIFAC method. In both cases, low root-mean-square deviations of the vapor mole fraction and temperature were calculated. The capability of 1-propanol as a modified distillation agent at atmospheric conditions is discussed in terms of thermodynamic topological analysis. However, because of the complex topology of the ternary mixture, it leads to a distillation scheme with two columns specifying ternary azeotrope recycling and difficult operation. Thus, this compound is not recommended as a separation agent for the binary benzene + cyclohexane azeotrope.

  1. 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…

  2. 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

  3. 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.

  4. 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...

  5. 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.

  6. 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.

  7. Influences of dehydrating process on properties of ATO nano-powders

    Institute of Scientific and Technical Information of China (English)

    吴湘伟; 陈振华; 黄培云

    2004-01-01

    Sb-doped SnO2 (ATO) nanometer powders were synthesized by hydrolysis of alkoxides, using SnCl4 ·5H2O and SbCl3 as raw materials. Some dehydrating processes, such as n-butanol/xylene mixed solvent heterogeneous azeotropic distillation, organic dehydrating agent and other dehydrating processes, were used to treat the wet colloids for preparing nonagglomerated ATO nanoparticles. The influences of dehydrating processes on the particle size, agglomeration and resistance were investigated using X-ray diffraction (XRD), transmission electron microscopy (TEM) and Brunauer-Emmet-Teller (BET). It is indicated that the dehydrating methods have great influences on the products properties, and that n-butanol/xylene mixed solvent heterogeneous azeotropic distillation processing and organic dehydrating agent can effectively remove the residual H2O molecules in wet colloids, and be used to prepare powders with high surface areas, about 85.32 m2/g, low agglomeration and good conductivity.

  8. 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.

  9. 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.

  10. Alternatives to R-502 and R-22; Alternativen zu R-502 und R-22

    Energy Technology Data Exchange (ETDEWEB)

    Wilms, M. [DuPont de Nemours International S.A, Genf (Switzerland); Gerstel, J. [DuPont de Nemours (Deutschland) GmbH, Bad Homburg (Germany); Zakrzewski, U. [DuPont de Nemours (Deutschland) GmbH, Bad Homburg (Germany)

    1994-12-31

    DuPont has recently presented the refrigerants SUVA AC9000 and SUVA HP62, an almost azeotropic mixture, as alternatives to R22 and R502. The search for new materials as refrigerants has ushered in a third generation of alternatives, such as, e.g. ether compounds. The present paper gives a detailed description of all three refrigerants. (BWI) [Deutsch] Als Alternativprodukte fuer R22 und R502 wurden von DuPont vor kurzem die Kaeltemittel SUVA AC9000 und SUVA HP62, ein fast azeotropes Gemisch. Bei der Suche nach neuen Arbeitsstoffen ist auch eine 3. Generation von Alternativen zunehmend in Diskussion gekommen, wie z.B. Etherverbindungen. Der vorliegende Beitrag stellt alle drei Kaeltemittel detailliert vor. (BWI)

  11. Alternatives to R 502 and R 22; Alternativen zu R-502 und R-22

    Energy Technology Data Exchange (ETDEWEB)

    Wilms, M. [DuPont de Nemours International S.A., Genf (Switzerland); Gerstel, J. [DuPont de Nemours (Deutschland) GmbH, Bad Homburg (Germany); Zakrzewski, U. [DuPont de Nemours (Deutschland) GmbH, Bad Homburg (Germany)

    1994-12-31

    Efforts to substitute fully and partially halogenated refrigerants have led to intensive research activities during the past years. DuPont has developed SUVA HP62, and almost azeotropic mixture, as an alternative to R502 and SUVA AC9000 as an alternative to R22. The search for new refrigerants has led to the emergence of a third generation of candidate substitutes, e.g. ether compounds. The present paper describes in detail the properties of the mentioned alternative refrigerants. (BWI) [Deutsch] Der Versuch voll- und teilhalogenierte Kaeltemittel zu ersetzen, fuehrten in den letzten Jahren zu intensiven Forschungstaetigkeiten. Als Alternative zu R502 wurde von DuPont das fast azeotrope Gemisch SUVA HP62 entwickelt, als Alternative zu R22 - SUVA AC9000. Bei der Suche nach neuen Arbeitsstoffen ist auch eine 3. Generation von Alternativen in Diskussion gekommen, z.B. Etherverbindungen. Der vorliegende Beitrag stellt die Eigenschaften der genannten Kaeltemittel-Alternativen detailliert dar. (BWI)

  12. Multiple Steady States in Distillation

    OpenAIRE

    Bekiaris, Nikolaos

    1995-01-01

    We study multiple steady states in distillation. We first analyze the simplest case of ternary homogeneous azeotropic mixtures. We show that in the case of infinite reflux and an infinite number of trays (∞/∞ case) one can construct bifurcation diagrams on physical grounds with the distillate flow as the bifurcation parameter. Multiple steady states exist when the distillate flow varies non-monotonically along the continuation path of the bifurcation diagram. We derive a necessary and suffici...

  13. 水平管群における二成分不溶性混合冷媒の凝縮熱伝達: イナンデーションの影響とモデル化

    OpenAIRE

    寺西, 恒宣; 牧野, 智也; 滝本, 昭; 林, 勇二郎

    1996-01-01

    This work was undertaken experimentally and analytically to acquire a better understanding of condensation heat transfer of binary vapors of immiscible liquids on horizontal tube banks. The characteristics of condensation heat transfer on lower tubes, which received condensates inundated at the upper tube banks, were clarified through detailed experiments using an azeotropic mixture of carbon tetrachloride and water as binary vapors. Due to the combination of the organic immutable behavior an...

  14. 二成分不溶性混合冷媒の凝縮熱伝達: 水平フィン付き円管上への凝縮

    OpenAIRE

    寺西, 恒宣; 滝本, 昭; 林, 勇二郎

    1994-01-01

    In order to enhance the condensation heat transfer of binary vapors of immiscible liquids, detailed experiments have been conducted with regard to the condensation of an azeotropic mixiture of carbon tetrachloride and water on horizontal tubes with enhanced fins. The condensation mechanism of this kind of vapor on horizontal tubes is clarified through the measurement of droplet departure frequency and heat transfer rates. The experimental results indicate that finned tubes are more effective ...

  15. 2成分不溶性混合冷媒の凝縮熱伝達: フィン付き面による伝熱促進

    OpenAIRE

    寺西, 恒宣; 滝本, 昭; 高橋, 信哉; 林, 勇二郎

    1992-01-01

    In order to pursue the enhancement of condensation heat transfer of binary vapors of immiscible liquids, detailed experiments have been conducted with regard to the condensation of an azeotropic mixture of carbon tetrachloride and water on vertical flat plates with enhanced fins. The condensation mechanism of this kind of vapor on finned surfaces was clarified through measurements of the droplets departure frequency and heat transfer rates. The experimental results indicate that finned surfac...

  16. 2成分不溶性混合冷媒の凝縮熱伝達に関する研究: 凝縮形態と熱伝達

    OpenAIRE

    滝本, 昭; 寺西, 恒宣; 羽根田, 完爾; 林, 勇二郎

    1991-01-01

    In order to clarify the condensation heat transfer mechanism of binary vapors of immiscible liquids, detailed experiments have been conducted with regard to the condensation of an azeotropic mixture of carbon tetrachloride and water on a vertical flat plate. The experimental results indicate that the condensation heat transfer coefficient of the mixture is larger than that of the pure organic vapor, and its mechanism can be explained to be in relation with the dynamic behavior of mixed conden...

  17. <報文>NOF-HF 系共沸混合物で 52°物質と名付けた溶液の蒸気圧測定

    OpenAIRE

    大川, 淳

    1994-01-01

    Vapor pressure of 52° material measured with direct method at room temperature to over the its boiling point. Relation of heating temperature and vapor pressure could be formularized as follow. log P(mmHg)=-1928/T+8.82 T : temperature K In the temperature range, 25∿52℃, chemical composition of azeotrope gas could be showen NOF・6HF・1.87HNO_3.

  18. A regression model for calculating the boiling point isobars of tetrachloromethane-based binary solutions

    Science.gov (United States)

    Preobrazhenskii, M. P.; Rudakov, O. B.

    2016-01-01

    A regression model for calculating the boiling point isobars of tetrachloromethane-organic solvent binary homogeneous systems is proposed. The parameters of the model proposed were calculated for a series of solutions. The correlation between the nonadditivity parameter of the regression model and the hydrophobicity criterion of the organic solvent is established. The parameter value of the proposed model is shown to allow prediction of the potential formation of azeotropic mixtures of solvents with tetrachloromethane.

  19. Synthesis and optimization of integrated chemical processes

    Energy Technology Data Exchange (ETDEWEB)

    Barton, Paul I.; Evans, Lawrence B.

    2002-04-26

    This is the final technical report for the project titled ''Synthesis and optimization of integrated chemical processes''. Progress is reported on novel algorithms for the computation of all heteroazeotropic compositions present in complex liquid mixtures; the design of novel flexible azeotropic separation processes using middle vessel batch distillation columns; and theory and algorithms for sensitivity analysis and numerical optimization of hybrid discrete/continuous dynamic systems.

  20. Determination of tritium in wine yeast samples

    International Nuclear Information System (INIS)

    Analytical procedures were developed to determine tritium in wine and wine yeast samples. The content of organic compounds affecting the LSC measurement is reduced by fractioning distillation for wine samples and azeotropic distillation/fractional distillation for wine yeast samples. Finally, the water samples were normally distilled with K MO4. The established procedures were successfully applied for wine and wine samples from Murfatlar harvests of the years 1995 and 1996. (authors)

  1. Sensitivity of Process Design due to Uncertainties in Property Estimates

    DEFF Research Database (Denmark)

    Hukkerikar, Amol; Jones, Mark; Sarup, Bent;

    2012-01-01

    accuracy for different thermo-physical property prediction models; and c) design variables versus properties relationships. The application of the methodology is illustrated through a case study of an extractive distillation process and sensitivity analysis of designs of various unit operations found in...... chemical processes. Among others vapour pressure accuracy for azeotropic mixtures is critical and needs to be measured or estimated with a ±0.25% accuracy to satisfy acceptable safety levels in design....

  2. Liquid-vapor equilibrium under elevated pressures in the systems formed by pentanes with sulfur compounds

    Energy Technology Data Exchange (ETDEWEB)

    Shakirzyanov, R.G.; Telyakov, E.S.; Serafimov, L.A.

    1982-10-20

    The possibility of removing sulfur compounds from the pentane fraction was studied. Experimental data obtained on liquid-vapor equilibrium in the system formed by pentanes with sulfur compounds under elevated pressures is presented. Vapor-liquid equilibrium was studied with the aid of a modified Swietoslawski apparatus made of stainless steel. Experimental data on phase equilibria of binary mixtures in the system studied are presented. The compositions and boiling points of binary azeotropes at the pressures studied are also presented.

  3. A Control Strategy for Reactive and Extractive Dividing-wall Columns

    OpenAIRE

    Rodriguez Hernandez, Manuel; Li, Ping Zhou; Diaz Moreno, Francisco Ismael

    2015-01-01

    Dividing-wall Columns (DWC) are being an important breakthrough in distillation technology due to the energy consumption and capital cost reduction they provide. There is an incresing amount of research papers devoted to DWCs although most of them present different applications and DWC setups like extractive DWC, azeotropic DWC or reactive DWC. These units have strong interactions in their operation and to achieve a good control is of great importance to guarantee a smooth and stable perfo...

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

    OpenAIRE

    I. D. Gil; L. C. García; Rodríguez, G.

    2014-01-01

    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 RadFr...

  5. Synthesis of nanosized powders for preparing ceramic membranes

    International Nuclear Information System (INIS)

    Magnesium-stabilized zirconia have been synthesized by a chemical route. The aim of this work is to obtain powders with suitable chemical and physical properties to be used as ceramic membranes for nanofiltration. The coprecipitation technique with an azeotropic distillation step has been employed for this purpose. Several powder characterization techniques have been utilized. The main results show that nanosized powders with high a degree of purity, high chemical homogeneity and elevated reactivity have been obtained. (orig.)

  6. Solid Liquid Extraction of Phenolic and Flavonoid Compounds from Cotinus coggygria and Concentration by Nanofiltration

    OpenAIRE

    Koleva, V.; Simeonov, E.

    2015-01-01

    Extraction kinetics of polyphenols and flavonoids from plant material and their separation and concentration by nanofiltration were investigated. The kinetics experiments were carried out with Cotinus coggygria. The influence of the extraction solvent on the extraction rate was defined. Four different extraction solvents or mixtures were applied – methanol, azeotropic ethanol, 50/50 ethanol/water mixture, and pure water. The optimum extraction rate of flavonoids and polyphenols was achieved b...

  7. Chloride workshop wastewater treatment measures%氯化物车间废水治理的措施

    Institute of Scientific and Technical Information of China (English)

    年立春

    2012-01-01

    介绍了采用共沸蒸馏的方法治理非酸性有机废水及利用生产盐酸的方法治理酸性废水的工艺过程。%According to the actual production of organic azeotropic distillation method of treatment of organic waste acid in the treatment of acidic wastewater process. plant chloride plant wastewater, introduce by water, as well as the production of hydrochloric

  8. 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.

  9. 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.

  10. Thermal desorption and recycling of volatile selective binders used in solid wastes deashing; Desorption thermique et recyclage d'agglomerants selectifs volatils utilises en decendrage de residus solides

    Energy Technology Data Exchange (ETDEWEB)

    Bensakhria, A.; Sajet, P.; Antonini, G. [Universite de Technologie de Compiegne, Centre de Recherches de Royallieu UMR 6067, Genie des Procedes Industriels, 60 - Compiegne (France)

    2001-07-01

    A pilot unit for the deashing of coal tailings by selective agglomeration and recovery of the binder/water mixture by azeotropic desorption of binders has been tested. The effect of different experiment parameters on the deashing efficiency, on the recovery and recycling of the binding agent have been tested. A 90% deashing level with a 94% recovery of the carbonaceous matter has been obtained with a recycling level of about 82% for the agglomerating agent. (J.S.)

  11. 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.

  12. 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.

  13. Kinematic Viscosity of R410A and R407C in the Saturated Liquid Phase%R410A和R407C饱和液相运动黏度测量

    Institute of Scientific and Technical Information of China (English)

    张颖; 何茂刚; 刘洋

    2011-01-01

    改进了倾斜管式黏度测量实验系统,使其能够适用于非共沸物质饱和液相黏度的测量.对制冷剂 R22的替代物质一近共沸二元混合制冷剂R410A和非共沸三元混合制冷剂R407C的饱和液相运动黏度进行了测量,实验温度范围为256.15~336.15 K.同时,依据实验数据建立了制冷剂R410A和R407C饱和液相运动黏度与温度的关联式.%The inclined-tube viscosity measurement system was improved to be used to measure the liquid phase viscosity of non-azeotropic mixtures. The kinematic viscosities of the binary near-azeotropic mixture R410A and the ternary non-azeotropic mixture R407C in the saturated liquid phase were measured at the temperatures ranging from 256.15 to 336.15 K. According to the experimental results, the equations correlating viscosity with temperature were established for both R410A and R407C.

  14. 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.

  15. 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.

  16. Computer aided design for entrainer in heteroazeotropic distillation by combining group contribution method with graph principle%结合图论和基团贡献法的非均相共沸精馏挟带剂设计

    Institute of Scientific and Technical Information of China (English)

    杨振生; 赵先兴; 李春利; 方静

    2012-01-01

    非均相共沸精馏挟带剂的计算机辅助分子设计(CAMD)由分子合成、分子筛选及分子确认3个环节递进构成.在分子合成环节,预选基团,限定合成分子的基团总数及类型,基于图论原理实现由基团到分子的自动合成.在分子筛选环节,依据基础物性筛选指标形成基础分子库,输入待分离物系,采用非均相共沸物形成判据筛选出若干候选分子.在分子确认环节,由非均相共沸温度及组成、挟带剂的汽化热等参数组成模糊综合评判函数,实现分子排序,从而输出一组较优挟带剂.以乙酸-水物系、乙腈-乙酸乙酯物系为例,得到了相应设计结果,与文献结果进行了对比.研究表明该方法及所编程序具备可靠实用性,可为近沸程及共沸混合物分离过程的开发与设计提供先导性支持.%Heterogeneous azeotropic distillation is an effective technology to separate close boiling point or homogeneous azeotropic mixture. The first step is to select appropriate entrainers. A computer aided molecular design (CAMD) methodology for the entrainer in heterogeneous azeotropic distillation is presented in this study. The CAMD methodology is comprised of three step-by-step stages, which are molecular synthesis, molecular screening and molecular recognition. In the stages of molecular synthesis, groups are pre-selected, the total number and types of the groups for the synthesized molecule are limited, and the automatic combination of groups is completed by using a graph algorithm. In the stages of molecular screening, the basic molecular library is formed by using several limited rules of basic physical properties, such as molecular weight and boiling point. The molecules in the basic molecular library are screened when they form the heterogeneous azeotropic with input components to be separated. As a result, a series of entrainer candidates are listed. In the stages of molecular recognition, the fuzzy comprehensive

  17. The role of OH…O and CH…O hydrogen bonds and H…H interactions in ethanol/methanol-water heterohexamers.

    Science.gov (United States)

    Mejía, Sol M; Espinal, Juan F; Mills, Matthew J L; Mondragón, Fanor

    2016-08-01

    Bioethanol is one of the world's most extensively produced biofuels. However, it is difficult to purify due to the formation of the ethanol-water azeotrope. Knowledge of the azeotrope structure at the molecular level can help to improve existing purification methods. In order to achieve a better understanding of this azeotrope structure, the characterization of (ethanol)5-water heterohexamers was carried out by analyzing the results of electronic structure calculations performed at the B3LYP/6-31+G(d) level. Hexamerization energies were found to range between -36.8 and -25.8 kcal/mol. Topological analysis of the electron density confirmed the existence of primary (OH…O) hydrogen bonds (HBs), secondary (CH…O) HBs, and H…H interactions in these clusters. Comparison with three different solvated alcohol systems featuring the same types of atom-atom interactions permitted the following order of stability to be determined: (methanol)5-water > (methanol)6 > (ethanol)5-water > (ethanol)6. These findings, together with accompanying geometric and spectroscopic analyses, show that similar cooperative effects exist among the primary HBs for structures with the same arrangement of primary HBs, regardless of the nature of the molecules involved. This result provides an indication that the molecular ratio can be considered to determine the unusual behavior of the ethanol-water system. The investigation also highlights the presence of several types of weak interaction in addition to primary HBs. Graphical Abstract Water-ethanol clusters exhibit a variety of interaction types between their atoms, such as primary OH...O (blue), secondary CH...O (green) and H...H (yellow) interactions as revealed by Quantum Chemical Topology. PMID:27417312

  18. 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。

  19. 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.

  20. Alkyl aryl ethers in lignite solubilization 1. Study of the process

    Energy Technology Data Exchange (ETDEWEB)

    Mastral, A.M.; Cebolla, V.L.; Gavilan, J.M.

    1984-10-01

    The chemistry of solubilization of a lignite has been investigated with anisole, 3-methyl anisole and 1,3dimethoxybenzene catalysed by SbCl/sub 3/, ZnCl/sub 2/, AlCl/sub 3/ and BF/sub 3/ as boron trifluoride etherate, at atmospheric pressure and temperatures <220/sup 0/C. 60% of lignite was solubilized in a toluene-ethanol azeotropic mixture. During the process, the solvent is incorporated as an alkylated substratum. The yield increased with activity of the aromatic ether ring and catalyst acidity.

  1. Alkyl aryl ethers in lignite solubilization. 1. Study of the process

    Energy Technology Data Exchange (ETDEWEB)

    Mastral, A.M.; Cebolla, V.L.; Gavilan, J.M.

    1984-10-01

    The chemistry of solubilization of a lignite has been investigated with anisole, 3-methyl anisole and 13-dimethoxybenzene catalysed by SbCl/sub 3/, ZnCl/sub 2/, AlCl/sub 3/ and BF/sub 3/ as boron trifluoride etherate, at atmospheric pressure and temperatures <220 C. 60% of lignite was solubilized in a toluene-ethanol azeotropic mixture. During the process, the solvent is incorporated as an alkylated substratum. The yield increased with activity of the aromatic ether ring and catalyst acidity. 14 references.

  2. 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...

  3. Measurement of VLE data for binary lipids systems

    DEFF Research Database (Denmark)

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

    components and also for their mixtures. To contribute in this area, experimental data were obtained using the Differential Scanning Calorimetry (DSC) technique for isobaric vapor-liquid equilibrium (VLE) of two binary mixtures at two different pressures (1.2 and 2.5 KPa): system 1 [monoacylglycerol...... is revealed for both systems at the two different pressures, with azeotrope behavior observed and confirmed but the relative volatility analysis. Available thermodynamic consistency tests for TPx data were applied before performing parameter regressions for Wilson NRTL, UNIQUAC and original UNIFAC models...

  4. 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....

  5. 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.

  6. 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.

  7. 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.

  8. Densities and isobaric vapor-liquid equilibria for the mixtures formed by four butyl esters and 1-butanol

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, E.; Ortega, J. [Univ. of Las Palmas de Gran Canaria (Spain)

    1996-01-01

    Densities of 298.15 K and the vapor-liquid equilibria for 1-butanol + butyl methanoate, + butyl ethanoate, + butyl propanoate, and + butyl butanoate have been measured at 101.32 kPa in small capacity ebulliometer. All results were found to be thermodynamically consistent with a point-to-point test. The mixtures containing butyl methanoate and butyl ethanoate show azeotropes at T = 379.14 K, x = 0.871 and T = 389.64 K, x = 0.222, respectively. Different group-contribution methods were applied to these mixtures.

  9. 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.

  10. Salt effect on the isobaric vapor-liquid equilibrium of the methyl acetate + methanol system

    Energy Technology Data Exchange (ETDEWEB)

    Iliuta, M.C.; Thyrion, F.C. [Louvain Univ., Louvain-la-Neuve (Belgium). Chemical Engineering Inst.; Landauer, O.M. [Univ. Politehnica Bucharest (Romania)

    1996-07-01

    The effect of sodium thiocyanate at constant salt mole fraction from 0.01 to 0.05 and at saturation on the vapor-liquid equilibrium (VLE) of methyl acetate + methanol has been studied at 101.32 kPa using a modified Othmer equilibrium still. The salt exhibited both salting-in and salting-out effects on the methyl acetate, the azeotrope being eliminated at saturation. The results were correlated using the extended UNIQUAC model of Sander et al. and the electrolytic NRTL model of Mock et al.

  11. Pervaporation membrane being shortly put to practical use. Jitsuyoka chikazuku pervaporation maku

    Energy Technology Data Exchange (ETDEWEB)

    Kai, M.

    1990-09-01

    Pervaporation (PV), said to be a compound word of permeation plus evaporation, is a new membrane separation technology, to separate/produce liquid mixture by simultaneously making the permeation and evaporation through the membrane. Its principle, trend in putting to practical use, etc. were introduced by the present report. The PV method is to supply the liquid mixture to the primary side of membrane and keep its secondary side depressurized to collect the permeated component under a form of vapor. All the components of liquid mixture are separated from one another by the difference in membrane-permeating speed. The main purpose of use might be the separation of azeotropic, multicomponent, analogic azeotropic and other mixtures. What is presently the most advanced in being put to practical use is dewatering of water-alcohol and other organic liquid, abundant in excellent records. According to reports, recently published, new membrane is energetic in research with published reports of its application to the waste water of factory, perfumery production, etc. 6 refs., 4 figs., 1 tab.

  12. 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.

  13. First Observation of Defined Structural Motifs in the Sulfur-Iodine Thermochemical Cycle and Their Role in Hydrogen Production

    International Nuclear Information System (INIS)

    The present paper investigates the ionic species coexisting in the HIx feed of the sulfur-iodine thermochemical cycle. For this purpose, Raman and inelastic neutron scattering as well as molecular modelling were applied to the study of the binary HI-H2O system and the ternary HI-I2-H2O and KI-I2-H2O systems. Raman spectra, obtained at 298 K, strongly suggest the coexistence of I3-, I-(I2), and I-(I2)2 species. Whereas on the other hand, inelastic neutron scattering spectra (20 K) revealed, for the first time, evidence for the presence of discrete water structural motifs under specific conditions. Molecular modelling of two idealized structures has allowed to establish a reasonable interpretation of the important structural motifs in these systems, in terms of the azeotrope of the HI-H2O system and the pseudo azeotrope of the HI-I2-H2O system.

  14. 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.

  15. 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.

  16. 碳酸二甲酯合成工艺模拟的研究进展%Progress in Simulation of Dimethyl Carbonate Synthesis Process

    Institute of Scientific and Technical Information of China (English)

    王峰; 赵宁; 李荣存; 武峰; 魏伟; 孙予罕

    2012-01-01

    The recent progresses in the simulation of the process and the product separation for synthesis of dimethyl carbonate(DMC)without onphosgene were reviewed. Many literatures focused on the simulation of DMC synthesis by transesterification method with reactive distillation. The catalytic distillation and the product separation for DMC synthesis from urea and methanol were introduced. The three processes for the product separation, namely pressure-swing distillation, extractive distillation and azeotropic distillation, were analyzed, in which the pressure-swing distillation process and the extractive distillation process were more effective for separation of methanol-DMC azeotrope.%综述了近年来碳酸二甲酯(DMC)的非光气法合成工艺和DMC产品的分离T艺的模拟研究报道.重点介绍了酯交换法反应精馏工艺和分离工艺的模拟结果,尿素醇解法催化精馏工艺的非平衡级模拟的结果.在DMC产物的变压精馏、萃取精馏和共沸精馏的主要分离工艺中,变压精馏和萃取精馏是分离甲醇-DMC共沸物效率较高的两种工艺.

  17. 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. 

  18. Feasibility and parametric study of tetrahydrofuran dehydration using reactive distillation with low energy requirement

    International Nuclear Information System (INIS)

    A new configuration of a RD (reactive distillation) process is investigated to break the THF (tetrahydrofuran)/water azeotrope using Hysys process software. The main module is a column system containing the reaction of EO (ethylene oxide) with water, in which top and bottom streams are the desired products, THF and EG (ethylene glycol), respectively. This contribution explores feasibility of using the reaction in the RD column and also describes the influence of reflux ratio, reaction trays, operating pressure and feed–inlet locations of the RD column in simulation environment. The results show that high purities of EG and THF are simultaneously obtained by this novel technique leading to more profits of the RD process. The optimal design of the RD process is obtained by minimizing the energy demand and the optimum number of reactive trays is found to be 10. Furthermore, minimum energy demand is observed when the column operates at atmospheric pressure with reflux ratio of 1.25. Particularly, it is found that the optimal reboiler duty per unit THF produced is reduced from 32 to 3.7% for the new process as compared to the conventional one, while both schemes predict similar outputs. - Highlights: • A reactive distillation column is proposed to produce pure tetrahydrofuran. • The tetrahydrofuran-water azeotrope is broken using reactive distillation column. • High energy saving (88%) is found for the reactive distillation process

  19. Alternatives to R-502 and-R22; Alternativen zu R-502 und R-22

    Energy Technology Data Exchange (ETDEWEB)

    Wilms, M. [DuPont de Nemours International S.A., Genf (Switzerland); Gerstel, J. [DuPont de Nemours (Deutschland), Bad Homburg (Germany); Zakrzewski, U. [DuPont de Nemours (Deutschland), Bad Homburg (Germany)

    1994-12-31

    The need to abandon CFCs has over the past years led to enhanced efforts to find out more about alternative materials. As a result of such work DuPont was recently able to present the new refrigerant SUVA AC9000, an alternative to R 22 suitable for air conditioners and heat pumps. SUVA HP62, an almost azeotropic mixture, has been developed as an alternative to R 502 and is mainly intended for new plants. A third generation of refrigerants, including ether compounds, is currently being developed. The present paper makes use of numerous performance diagrams to describe the properties of these refrigerants. (BWI) [Deutsch] Durch den Versuch, den Einsatz von FCKWs zu vermeiden, werden seit Jahren vermehrt Anstrengungen zur Erforschung von Alternativstoffen unternommen. Als Ergebnis wurde von DuPont vor kurzem das neue Kaeltemittel SUVA AC9000 als Alternative fuer R22 in Klimageraeten und Waermepumpen. Als R502-Alternative wurde das fast azeotrope Gemisch SUVA HP62 entwickelt, das vornehmlich in Neuanlagen zum Einsatz kommt. Derzeit wird die 3. Generation von Kaeltemitteln, wie z.B. Etherverbindungen, untersucht. Der vorliegende Beitrag stellt die Eigenschaften dieser Kaeltemittel anhand von zahlreichen Leistungsdiagrammen vor. (BWI)

  20. Synthesis of alkylfurans from. gamma. -oxoaldehydes. gamma. -oxoaldehyde wo genryotosuru alkylfuran rui no gosei

    Energy Technology Data Exchange (ETDEWEB)

    Tsukasa, H. (Toyotama Perfumery, Co. Ltd., Tokyo (Japan))

    1991-06-20

    2-Alkyl 3-or 4-methy1 furans and 2-alkylfurans, which are compounds naturally produced, were synthesized from {gamma}-oxoaldehydes or {gamma}-oxoaldehyde acetals. 3-Methyl-4-oxoaldehydes were synthesized in 48 to 60% yields from aliphatic aldehyde and crotonaldehyde through a radical addition reaction. Treatment of {gamma}-oxoaldehydes with pyrophosphoric acid in benzene under reflux with the azeotropic removal of water gave alkylfurans in 3 to 42% yields. Alkylfurans were also obtained in 35 to 78% yields through the dropwise addition of {gamma}-oxoaldehyde acetal under reduced pressure. Futhermore, menthofurans, which are a minor but important olfactive ingredient of peppermint oil, were obtained in a 64% yield from 9,10-epoxy-3,3-ethylenedioxy-p-menthane. 15 refs., 2 tabs.

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

    International Nuclear Information System (INIS)

    A simple method was developed for the separation of radioactive 77As from neutron irradiated natural GeO2 samples for environmental and biochemical studies. The method is based on the volatility of GeCl4. The GeCl4 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 77Ge the separation process can be repetitive, getting a special type of 77Ge/77As 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.

  4. Effects of Fe/C phase separation on the ages of white dwarfs

    Science.gov (United States)

    Xu, Z. W.; Van Horn, H. M.

    1992-01-01

    The energy release associated with the phase separation of Fe from C in a predominantly C white dwarf is calculated. The total gravitational-plus-internal energy differences between models of homogeneous compositions and those wth Fe-enriched cores are computed. In the unlikely case where the core is pure Fe, a substantial extension of the white dwarf cooling times is found, even with the small cosmic abundance of this element. For the more realistic core compositions that result if the Fe/C phase diagram is either of the spindle or of the azeotropic type, the energy release is still sufficient to prolong the cooling times by about 0.6 Gyr, comparable to that produced by C/O phase separation. Phase separation is found to produce an appreciable 'bump' in the luminosity function, although not one large enough to exceed the observational errors at low luminosities.

  5. 混合分离过程的有序设计框架%A Framework for the Systematic Design of Hybrid Separation Processes

    Institute of Scientific and Technical Information of China (English)

    W.Marquardt; S.Kossack; K.Kraemer

    2008-01-01

    The design of optimal separation flow sheets for multi-component mixtures is still not a solved problem. This is especially the case when non-ideal or azeotropic mixtures or hybrid separation processes are considered. We review recent developments in this field and present a systematic framework for the design of separation flow sheets. This framework proposes a three-step approach. In the first step different flow sheets are generated. In the second step these alternative flow sheet structures are evaluated with shortcut methods. In the third step a rigorous mixed-integer nonlinear programming (MINLP) optimization of the entire flow sheet is executed to determine the best alternative. Since a number of alternative flow sheets have already been eliminated, only a few optimization runs are necessary in this final step. The whole framework thus allows the systematic generation and evaluation of separation processes and is illustrated with the case study of the separation of ethanol and water.

  6. 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.

  7. 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%.

  8. 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.

  9. Isobaric vapor liquid equilibria data for the binary system (glycidyl butyrate + acetone, glycidyl butyrate + carbon tetrachloride, glycidyl butyrate + chloroform) at atmospheric pressure 101 kPa

    Science.gov (United States)

    Huang, Qiang; Meng, Qingyi; Ban, Chunlan; Zhang, Rui; Gao, Yingyu

    2016-09-01

    Isobaric vapor liquid equilibria (VLE) for the binary mixtures of glycidyl butyrate(1) + acetone(2), glycidyl butyrate(1) + carbon tetrachloride(2) and glycidyl butyrate(1) + chloroform(2) at 101 kPa were studied. The experimental data were satisfactorily correlated with the models of Wilson, NRTL and UNIQUAC activity coefficients. The activity coefficients for the equilibrium data were obtained by the nonlinear least square method. The average relative deviations between experimental temperatures and calculated temperatures by the Wilson, NRTL and UNIQUAC models were 0.16, 0.16, 0.23% for glycidyl butyrate(1) + chloroform( 2), 0.38, 0.12, 0.27% for glycidylbutyrate(1) + carbon tetrachloride(2), and 0.67, 0.13, 0.54% for glycidyl butyrate(1) + acetone(2). Azeotrope behavior was not found for these systems. The thermodynamic consistency of the correlations was checked by the Herrington's area test.

  10. Design and Control of Glycerol-tert-Butyl Alcohol Etherification Process

    Directory of Open Access Journals (Sweden)

    Elena Vlad

    2012-01-01

    Full Text Available Design, economics, and plantwide control of a glycerol-tert-butyl alcohol (TBA etherification plant are presented. The reaction takes place in liquid phase, in a plug flow reactor, using Amberlyst 15 as a catalyst. The products' separation is achieved by two distillation columns where high-purity ethers are obtained and a section involving extractive distillation with 1,4-butanediol as solvent, which separates TBA from the TBA/water azeotrope. Details of design performed in AspenPlus and an economic evaluation of the process are given. Three plantwide control structures are examined using a mass balance model of the plant. The preferred control structure fixes the fresh glycerol flow rate and the ratio glycerol + monoether : TBA at reactor-inlet. The stability and robustness in the operation are checked by rigorous dynamic simulation in AspenDynamics.

  11. Recovery of Alcohols and Esters in Plasticizer Wastewater%增塑剂废水中醇酯的回收

    Institute of Scientific and Technical Information of China (English)

    郝鹏飞

    2012-01-01

    To do an separation and purification experiment of the plasticizer wastewater mixed alcohols and esters. To adopt the reduced pressure steam distillation to get mixed esters using the existing production equipment,then to get octyl alcohol by azeotropic distillation,and put forward some suggestions in the purification of the butyl alcohol by atmospheric distillation.%对增塑剂生产废水中回收的混合醇酯的分离与提纯进行实验。利用现有生产设备,先减压蒸馏、气提,得到混合酯,再采用恒沸蒸馏的方法从混合醇中分离辛醇,并提出常压精馏提纯丁醇的方法。

  12. 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)

  13. Determination of tritium in wine and wine yeast samples

    International Nuclear Information System (INIS)

    A sensitive method for evaluating the tritium content in wine and wine yeast was applied to estimate tritium impact on the environment in the surrounding area of nuclear power plant Cernavoda, where the vineyards are part of representative agricultural ecosystem. Analytical procedures were developed to determine HTO in wine and wine yeast samples. The content of organic compounds affecting the LSC measurement is reduced by fractionating distillation for wine samples and azeotropic distillation followed by fractional distillation for wine yeast samples. Finally, the water samples obtained after fractional distillation were normally distilled with KMO4. The established procedures were successfully applied for wine and wine yeast samples from Mulfatlar harvests of the years 1995 and 1996. (authors)

  14. Analytical Phase Equilibrium Function for Mixtures Obeying Raoult's and Henry's Laws

    Science.gov (United States)

    Hayes, Robert

    When a mixture of two substances exists in both the liquid and gas phase at equilibrium, Raoults and Henry's laws (ideal solution and ideal dilute solution approximations) can be used to estimate the gas and liquid mole fractions at the extremes of either very little solute or solvent. By assuming that a cubic polynomial can reasonably approximate the intermediate values to these extremes as a function of mole fraction, the cubic polynomial is solved and presented. A closed form equation approximating the pressure dependence on mole fraction of the constituents is thereby obtained. As a first approximation, this is a very simple and potentially useful means to estimate gas and liquid mole fractions of equilibrium mixtures. Mixtures with an azeotrope require additional attention if this type of approach is to be utilized. This work supported in part by federal Grant NRC-HQ-84-14-G-0059.

  15. Recovery of Styrene in Residue Tar Discharged from Styrene Distillation Separation Process%苯乙烯蒸馏残焦油中粗品苯乙烯的回收工艺

    Institute of Scientific and Technical Information of China (English)

    杨运泉; 段正康; 刘文英

    2001-01-01

    Based on the characteristic that styrene can form ternary azeotrope with some special organic solvents and water,a new separation process for recovery of styrene in residue tar discharged from the bottom of styrene distillation tower has been developed.The recovery rate of styrene in the tar is nearly 92%;the mass fraction of crude product styrene is 98%.%利用苯乙烯能与某些特定溶剂及水形成三元共沸物的特点,开发出从苯乙烯蒸馏塔釜排放的残焦油中提取粗品苯乙烯的新工艺。苯乙烯回收率可达92%以上,粗品苯乙烯的含量在98%(质量分数)以上。

  16. 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.

  17. 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.

  18. 萃取精馏溶剂选择性的温度效应%INFLUENCE OF TEMPERATURE ON SOLVENT SELECTIVITY FOR EXTRACTIVE DISTILLATION

    Institute of Scientific and Technical Information of China (English)

    张志刚; 徐世民; 李鑫钢; 张卫江

    2004-01-01

    Extractive distillation is an important and useful technique for separating close boiling and azeotropic liquid mixtures. Solvent selectivity is the key to achieving success. In this paper, the relation of solvent selectivity uersus temperature for different mixed systems (C6H6 + C6H12 + DMSO,C6H6 + C6H12+DMF, EtOH + EA + DMF + DMSO, C6H6 + C6 H12 + DMF + DMSO) was examined by the modified UNIFAC model, which is a well-tested method to select a solvent for extractive distillation.With increasing temperature, solvent selectivity was decreased. In addition, the influence of temperature on solvent selectivity was set forth for the first time by using the Clausius-Mosotti equation.

  19. Radwaste volume reduction and solidification by General Electric

    International Nuclear Information System (INIS)

    Since 1978 General Electric has been actively engaged in developing a volume reduction and solidifcation system or treatment of radwaste generated in commercial nuclear power plants. The studies have been aimed at defining an integrated system that would be directly responsive to the rapid evolving needs of the industry for the volume reduction and solidification of low-level radwaste. The resulting General Electric Volume Reduction System (GEVRS) is an integrated system based on two processes: the first uses azeotropic distillation technology and is called AZTECH, and the second is controlled-air incineration...called INCA. The AZTECH process serves to remove water from concentrated salt solutions, ion exchange resins and filter sludge slurries and then encapsulates the dried solids into a dense plastic product. The INCA unit serves to reduce combustible wastes to ashes suitable for encapsulation into the same plastic product produced by AZTECH

  20. 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.

  1. Achieving process intensification form the application of a phenomena based synthesis, Design and intensification methodology

    DEFF Research Database (Denmark)

    Babi, Deenesh Kavi; Lutze, Philip; Woodley, John;

    Process Intensification/Process Systems Engineering. Process intensification (PI) is a means by which one can achieve a more efficient and sustainable chemical process. Major success in the area of PI has been achieved by Eastman chemicals [1] which in 1984 intensified the process...... of PI still faces challenges [2] because the identification and design of intensified processes is not simple [3]. Lutze et al [3] has developed a systematic PI synthesis/design method at the unit operations (Unit-Ops) level, where the search space is based on a knowledge-base of existing PI equipment...... for the manufacture of methyl acetate by replacing with one single reactive distillation column the multi-step process which consisted of one reactor, extractive distillation, liquid-liquid separation and azeotropic distillation. However, except for reactive distillation and dividing wall columns, the implementation...

  2. Design of environmentally benign processes

    DEFF Research Database (Denmark)

    Hostrup, Martin; Harper, Peter Mathias; Gani, Rafiqul

    1999-01-01

    This paper presents a hybrid method for design of environmentally benign processes. The hybrid method integrates mathematical modelling with heuristic approaches to solving the optimisation problems related to separation process synthesis and solvent design and selection. A structured method...... of solution, which employs thermodynamic insights to reduce the complexity and size of the mathematical problem by eliminating redundant alternatives, has been developed for the hybrid method. Separation process synthesis and design problems related to the removal of a chemical species from process streams...... because of environmental constraints are particularly suited for solution with the hybrid method. Application of the hybrid method is highlighted through two illustrative examples. The first example involves the determination of an optimal flowsheet for the removal of a chemical species from an azeotropic...

  3. Design and control of an alternative distillation sequence for bioethanol purification

    DEFF Research Database (Denmark)

    Errico, Massimiliano; Ramírez-Márquez, César; Torres Ortega, Carlo Edgar;

    2015-01-01

    BACKGROUND: Bioethanol is a green fuel considered to be a sustainable alternative to petro-derived gasoline. The transport sector contributes significantly to carbon dioxide emission and consequently has a negative impact on the air quality and is responsible for the increase of the greenhouse...... separation is presented. The steady state performance and the dynamic beavior are analyzed compared with the classical configuration reported in the literature. RESULTS: Ethanol-water azeotropic separation represents a challenge for bioethanol purification. Usually a three column sequence is used to obtain...... fuel grade bioethanol by extractive distillation. In order to reduce bioethanol purification cost a two column separation sequence is proposed. This configuration shows a 10% saving in capital costs together with higher ethanol recovery and better control properties compared with the classical three...

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Effect of calcium chloride on the isobaric vapor-liquid equilibrium of 1-propanol + water

    Energy Technology Data Exchange (ETDEWEB)

    Iliuta, M.C.; Thyrion, F.C. [Louvain Univ., Louvain-la-Neuve (Belgium). Chemical Engineering Inst.; Landauer, O.M. [Univ. Politehnica Bucharest (Romania)

    1996-05-01

    The effect of calcium chloride at salt mole fractions from 0.02 to saturation on the vapor-liquid equilibrium (VLE) of 1-propanol + water has been studied at 101.32 kPa using a modified Othmer equilibrium still. The salt exhibited a salting-out effect of the alcohol over the whole range of liquid composition, the azeotrope being eliminated at salt mole fractions greater than 0.080. A liquid phase splitting into two immiscible liquid phases on the whole range of salt concentration and over a liquid range of about 0.01--0.54 1-propanol mole fraction (salt-free basis) was observed. The results were compared with the values predicted from the extended UNIQUAC models of Sander et al. and Macedo et al. and the modified UNIFAC group-contribution model of Kikic et al.

  9. 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.).

  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. 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.

  12. 冷凝式油气回收系统设计研究%Design and study on condensation refueling gas recovery system

    Institute of Scientific and Technical Information of China (English)

    杨叶; 王铁军; 王蒙; 朱志平; 缪志华; 张贵德

    2012-01-01

    设计了一种冷凝式油气回收系统,其制冷系统由单级压缩预冷单元与单级压缩2级自动复叠单元复叠而成.应用物性软件REFPROP对混合制冷剂的性质进行分析,应用大型通用流程模拟软件对油气负荷及制冷流程进行了模拟计算,研究了非共沸混合制冷剂配比变化对自动复叠单元压缩机性能的影响;通过对系统的模拟运行,研究了该冷凝式油气回收系统的工作性能,分析了冷凝温度对油气回收率和尾气油气含量的影响;在系统分析和模拟研究的基础上,为冷凝式油气回收系统关键设计参数选择提供了理论依据.%A condensation refueling gas recovery system was designed in this paper, in which the three - stage cascade refrigeration system was composed of single - stage compression pre - cooling unit and two - stage auto cascade unit. In order to syudy the effect of the proportion of the non azeotropic mixture refrigerant on the performance of the compressor used in the auto cascade unit, the software REFPROP was employed to analyze the physical properties of the non azeotropic mixture refrigerant and a common process simulation software was applied to emulate the refrigeration process and compute the load used to condense the refueling gas. According to the simulation results, the performance of condensation refueling gas recovery system was studied and the influence of the condensation temperature on the refueling gas recovery rate and the refueling gas content of the off - gas was analyzed. Based on the system analysis and simulation studies, a criterion to choose the key design parameters for the condensation refueling gas recovery system was given.

  13. 碳酸二甲酯提纯方法的研究进展%Study Progress on the Purification Methods of Dimethyl Carbonate

    Institute of Scientific and Technical Information of China (English)

    张丽红; 张艳华

    2012-01-01

    To summary the purification methods of dimethyl carbonate including industry-scal and battery-scal dimethyl carbonate.About purification of industry-scal dimethyl carbonate,to detaily introduce the separation of methanol-dimethyl carbonate azeotrope including membrane separation,adsorption separation,high-pressure distillation azeotripic distillation and extractive distillation.Separation methods of membrane or adsorption,which had the characteristics of low energy consumption and high efficiency,were new separation methods.High-pressure distillation,azeotropic distillation and extractive distillation,which had less investment,operated more expediently,obtained higher purity product,and had wider industrial foreground.About purification of battery-scal dimethyl carbonate,crystallization used simple equipment,operated more expediently,consumed less energy,showed more advantage than distillation.%综述了碳酸二甲酯提纯方法的最新研究进展,分别介绍了工业级和电池级碳酸二甲酯的提纯方法。在工业级碳酸二甲酯的提纯方法中,详细介绍了碳酸二甲酯-甲醇二元共沸物的分离方法,在各种分离方法中,膜分离和吸附分离能耗低、效率高,属于新型的分离方法;加压精馏、共沸精馏和萃取精馏具有投资较小、操作方便、产品纯度高等优势,具有较高的工业应用价值。在电池级碳酸二甲酯的提纯方法中,冷却结晶法具有设备简单、操作方便、节能的优点,比精馏法更具优势。

  14. A Comparison of Soil-Water Sampling Techniques

    Science.gov (United States)

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

    2007-12-01

    The representativeness of soil pore water extracted by suction lysimeters in ground-water monitoring studies is a problem that often confounds interpretation of measured data. Current soil water sampling techniques cannot identify the soil volume from which a pore water sample is extracted, neither macroscopic, microscopic, or preferential flowpath. This research was undertaken to compare values of extracted suction lysimeters samples from intact soil cores with samples obtained by the direct extraction methods to determine what portion of soil pore water is sampled by each method. Intact soil cores (30 centimeter (cm) diameter by 40 cm height) were extracted from two different sites - a sandy soil near Altamonte Springs, Florida and a clayey soil near Centralia in Boone County, Missouri. Isotopically labeled water (O18? - analyzed by mass spectrometry) and bromide concentrations (KBr- - measured using ion chromatography) from water samples taken by suction lysimeters was compared with samples obtained by direct extraction methods of centrifugation and azeotropic distillation. Water samples collected by direct extraction were about 0.25 ? more negative (depleted) than that collected by suction lysimeter values from a sandy soil and about 2-7 ? more negative from a well structured clayey 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. In cases where a sufficient volume of water has passed through the soil profile and displaced previous pore water, suction lysimeters will collect a representative sample of soil pore water from the sampled depth interval. It is suggested that for stable isotope studies monitoring precipitation and soil water, suction lysimeter should be installed at shallow depths (10 cm). Samples should also be coordinated with precipitation events. The data also indicate that each extraction method be use to sample a different

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Isolation of levoglucosan from pyrolysis oil derived from cellulose

    Science.gov (United States)

    Moens, Luc

    1994-01-01

    High purity levoglucosan is obtained from pyrolysis oil derived from cellulose by: mixing pyrolysis oil with water and a basic metal hydroxide, oxide, or salt in amount sufficient to elevate pH values to a range of from about 12 to about 12.5, and adding an amount of the hydroxide, oxide, or salt in excess of the amount needed to obtain the pH range until colored materials of impurities from the oil are removed and a slurry is formed; drying the slurry azeotropically with methyl isobutyl ketone solvent to form a residue, and further drying the residue by evaporation; reducing the residue into a powder; continuously extracting the powder residue with ethyl acetate to provide a levoglucosan-rich extract; and concentrating the extract by removing ethyl acetate to provide crystalline levoglucosan. Preferably, Ca(OH).sub.2 is added to adjust the pH to the elevated values, and then Ca(OH).sub.2 is added in an excess amount needed.

  20. An intermediate heat exchanging-depressurizing loop for nuclear hydrogen production

    International Nuclear Information System (INIS)

    Sulfur-iodine (SI) cycle should overcome many engineering challenges to commercialize and prove its feasibilities to compete other thermo-chemical cycles. Some critical issues such as structural material, harsh operating condition and high capital costs were considered obstacles to be actualized. Operating SI cycle at low-pressure is one of the solutions to actualize the cycle. The flash operation with over-azeotropic HI at low pressure does not require temperature and pressure as high as those in the existing methods as well as heating for separation. The operation in low pressure reduces corrosion problems and enables us to use flexible selection of structural material. We devised an intermediate heat exchanging-depressurizing loop to eliminate high operating pressure in the hydrogen side as well as a large pressure difference between the reactor side and the hydrogen side. Molten salts are adequate candidates as working fluids under the high-temperature condition with homogeneous phase during pressure changing process. Using molten salts, 2.20-4.65 MW of pumping work is required to change the pressure from 1 bar to 7 MPa. We selected BeF2-containing salts as the possible candidates based on preliminary economic and thermal hydraulic consideration.

  1. 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.

  2. 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.

  3. Boronic, diboronic, and α-amino-boronic acids derived from 1-ethynyl-3, 4-dimethoxybenzene

    International Nuclear Information System (INIS)

    This work was undertaken with the intention of synthesizing (α-amino-β-(3, 4-dihydroxyphenyl) ethylboronic acid. Unfortunately, the goal could not be attained since the isolation of the target compound could not be achieved though some information suggested its existence in the final product. The methods of synthesis used in the second half of the attempted preparation are described here (compounds in the first half have been published elsewhere). In this procedure, (β-(3, 4-dimethoxyphenyl)) ethenylboronic acid is esterified and azeotropic distillation is conducted to provide diethyl (β-(3, 4-dimethoxyphenyl)) ethenylboronate. This compound is dissolved in diglyme and diborane gas is introduced. The hydroboration product is then subjected to amination with hydroxylamine-0-sulfonic acid. (β-(3, 4-dimethoxyphenyl)) ethyl-α, α-diboronic acid is obtained from the residue of acetone extraction. The acetone extract is concentrated to a solid caramel, from which (α-borono-β-(3, 4-dimethoxyphenyl)) ethylammonium tetraphenylborate is formed. Conversion from the tetraphenylborate salt to (α-amino-β-(3, 4-dimethoxyphenyl)) ethylboronic acid hydrochloride is attempted by the double decomposition RH BPh4 + CsCl -- RH Cl + CsBPh4. The product is subjected to demethylation and treated with sodium tetraphenylborate to precipitate (α-borono-β-(3, 4-dihydroxyphenyl)) ethylammonium tetraphenylborate. Conversion of this to the target compound is tried by double decomposition. (Nogami, K.)

  4. 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.

  5. 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.

  6. 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%.

  7. 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.

  8. 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.

  9. 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.

  10. Dewatering of HI{sub x} solutions by pervaporation through Nafion {sup registered} membranes

    Energy Technology Data Exchange (ETDEWEB)

    Elder, Rachael H.; Priestman, Geoffrey H.; Allen, Ray W.K. [Department of Chemical and Process Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom)

    2009-08-15

    The Sulphur Iodine (SI) thermochemical cycle is a promising route for hydrogen production from water. It requires the processing of a complex solution, termed HI{sub x}, which contains HI, H{sub 2}O, very high concentrations of I{sub 2}, plus a range of iodide species. Process efficiency can be improved by dewatering the HI{sub x} stream beyond its azeotropic point. This paper reports work aimed at achieving this by pervaporation through a membrane operating at the harsh process conditions involved. Nafion {sup registered} 117 and Nafion {sup registered} 212 are investigated using both a batch and a continuous flow arrangement operating with a range of HI-H{sub 2}O and HI-H{sub 2}O-I{sub 2} solution concentrations, up to the expected SI cycle composition. Permeates of almost pure water and reasonable fluxes are seen, and good correspondence is observed between the results from the two rigs. Consideration of the solution-diffusion model suggests that sorption and desorption, as well as diffusion, play a limiting role in the permeate flux. (author)

  11. 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.

  12. 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。

  13. 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.

  14. Room temperature inorganic polycondensation of oxide (Cu{sub 2}O and ZnO) nanoparticles and thin films preparation by the dip-coating technique

    Energy Technology Data Exchange (ETDEWEB)

    Salek, G.; Tenailleau, C., E-mail: tenailleau@chimie.ups-tlse.fr; Dufour, P.; Guillemet-Fritsch, S.

    2015-08-31

    Oxide thin solid films were prepared by dip-coating into colloidal dispersions of oxide nanoparticles stabilized at room temperature without the use of chelating or complex organic dispersing agents. Crystalline oxide nanoparticles were obtained by inorganic polycondensation and characterized by X-ray diffraction and field emission gun scanning electron microscopy. Water and ethanol synthesis and solution stabilization of oxide nanoparticle method was optimized to prepare two different structural and compositional materials, namely Cu{sub 2}O and ZnO. The influence of hydrodynamic parameters over the particle shape and size is discussed. Spherical and rod shape nanoparticles were formed for Cu{sub 2}O and ZnO, respectively. Isoelectric point values of 7.5 and 8.2 were determined for cuprous and zinc oxides, respectively, after zeta potential measurements. A shear thinning and thixotropic behavior was observed in both colloidal sols after peptization at pH ~ 6 with dilute nitric acid. Every colloidal dispersion stabilized in a low cost and environmentally friendly azeotrope solution composed of 96 vol.% of ethanol with water was used for the thin film preparation by the dip-coating technique. Optical properties of the light absorber cuprous oxide and transparent zinc oxide thin solid films were characterized by means of transmittance and reflectance measurements (300–1100 nm). - Highlights: • Room temperature inorganic polycondensation of crystalline oxides • Water and ethanol synthesis and solution stabilization of oxide nanoparticles • Low cost method for thin solid film preparation.

  15. 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.

  16. Metal fluorides

    International Nuclear Information System (INIS)

    Systems formed by fluorides of alkali, alkali earth, rare earth elements, yttrium, zirconium, hafnium, bismuth, antimony are investigated with the aim of preparing new fluoride materials and studying their thermodynamic and other physical and chemical properties. The respective phase diagrams are plotted. On the basis of the research fluoroberyllate glasses with rare earth additions of improved qualities (moisture resistance, crystallization resistance, resistance against radiation up to 100 Mrad) are prepared. The rho-T-x phase diagrams of the systems studied show that many compounds are sublimated congruently at certain temperatures and incongruently - above them. The existence of congruently sublimated compounds and azeotropically sublimated compositions provides for the preparation of uniform optical films. In connection with the search for new materials-luminophores and matrices of optical quantum generators - the fluoride systems of alkali metals and lanthanides are studied; the formation of binary fluorides of M3LnF6, M2LnF5, MLnF4, MLn2F7, MLn3F10 compositions is established. To search for new solid electrolytes, the solid-phase interaction of Sb-and Bi trifluorides with their oxides and alakali metal fluorides is studied. The electric conductivity of the compounds obtained is studied

  17. 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. PMID:27178937

  18. 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...

  19. 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.

  20. Ethanol fuels in Brazil

    International Nuclear Information System (INIS)

    The largest alternative transportation fuels program in the world today is Brazil's Proalcool Program. About 6.0 million metric tons of oil equivalent (MTOE) of ethanol, derived mainly from sugar cane, were consumed as transportation fuels in 1991 (equivalent to 127,000 barrels of crude oil per day). Total primary energy consumed by the Brazilian economy in 1991 was 184.1 million MTOE, and approximately 4.3 million vehicles -- about one third of the total vehicle fleet or about 40 percent of the total car population -- run on hydrous or open-quotes neatclose quotes ethanol at the azeotropic composition (96 percent ethanol, 4 percent water, by volume). Additional transportation fuels available in the country are diesel and gasoline, the latter of which is defined by three grades. Gasoline A (regular, leaded gas)d has virtually been replaced by gasoline C, a blend of gasoline and up to 22 percent anhydrous ethanol by volume, and gasoline B (premium gasoline) has been discontinued as a result of neat ethanol market penetration

  1. 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.

  2. 甲醇与碳酸二甲酯共沸物体系汽液平衡的计算%Prediction of Vapor-liquid Equilibrium of Dimethyl-carbonate-methanol System

    Institute of Scientific and Technical Information of China (English)

    张立庆; 孙素敏

    2001-01-01

    利用共沸点数据,运用计算机编程,采用EOS+r法分别用Wilson,NRTL和UNIFAC方程计算了碳酸二甲酯-甲醇二元体系在常压和加压下的汽液平衡。三种不同模型的计算结果与实验值都较为吻合,其中以UNIFAC方程的拟合结果为最好。%Boiling point and azeotropic data were used to predict critical parameter of dimethyl carbonate. Therefore several physical-chemical properities of dimethyl carbonate were estimated. The binary (dimetyl carbonate-methanol) system vapor liquid equilibrium in normal pressure and high pressure was predicted using Wilson equation, NRTL equation and UNIFAC model respecitively. The calculated results of three different models are in perfect agreement with experiment data. The calculated results of UNIFAC equation is the best in several models. So the results can be used for Chemical engineering calculation.

  3. Production of glycerol carbonate via reactive distillation and extractive distillation:An experimental study☆

    Institute of Scientific and Technical Information of China (English)

    Huajun Wang; Lei Pang; Chao Yang; Yihua Liu

    2015-01-01

    A process for the production of glycerol carbonate (GC) is proposed with the transesterification of glycerol (GL) and dimethyl carbonate (DMC) with CaO as catalyst by reactive distil ation and extractive distil ation. The perfor-mance of solvents in separating DMC-methanol azeotrope and the effects of operation parameters on the reactive distillation process are investigated experimental y. The results indicate that both the GL conversion and GC yield increase with the DMC/GL molar ratio, reflux ratio, final temperature of tower bottom, and CaO/GL molar ratio and decrease as the recycle number of CaO increases. The calcium concentration in the residual reaction mixture also decreases remarkably as the DMC/GL molar ratio increases. At DMC/GL molar ratio 4.0, reflux ratio 1.0, final temperature of tower bottom 358 K, and CaO/GL molar ratio 0.05, both the GL conversion and GC yield can reach above 99.0%, and the mass concentration of calcium in the product is less than 0.08%.

  4. Establishing a routine procedure for extraction of water from vegetation samples

    International Nuclear Information System (INIS)

    Full text: The Cryogenic Pilot is an experimental project within the nuclear energy national research program, which has the aim of developing technologies for tritium and deuterium separation by cryogenic distillation. The process, used in this installation, is based on a combined method for liquid-phase catalytic exchange (LPCE) and cryogenic distillation. There are two ways that Cryogenic Pilot can interact with the environment: by atmospheric release and by sewage. In order to establish the base line of tritium concentration in the environment around the nuclear facilities we investigated the preparation procedure for different type of samples: soil, hay, apple, grass, milk, meat and water. For azeotropic distillation of all types of samples two solvents were used, toluene and cyclohexane, and all measurements for determination of environmental tritium concentration were carry out using liquid scintillation counting (LSC), with ultra-low level liquid scintillation spectrometer Quantulus 1220 specially designed for environmental samples and low radioactivity. Sample scintillation cocktail ratio was 8:12 ml and liquid scintillation cocktail was UltimaGold LLT. The background determined for control samples prepared ranged between 0.926 Cpm and 1.002 Cpm and counting efficiency between 25.3% and 26.1%. The counting time was 1000 minutes (50 minutes/20 cycles) for each sample, and minimum detectable activity according to ISO 9698 was 8.9 TU, and 9.05 TU, respectively, with a confidence coefficient of 3. (authors)

  5. 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.

  6. 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.

  7. Transferable force field for alcohols and polyalcohols.

    Science.gov (United States)

    Ferrando, Nicolas; Lachet, Véronique; Teuler, Jean-Marie; Boutin, Anne

    2009-04-30

    A new force field has been developed for alcohol and polyalcohol molecules. Based on the anisotropic united-atom force field AUA4 developed for hydrocarbons, it only introduces one new anisotropic united atom corresponding to the hydroxyl group OH. In the case of polyalcohols and complex molecules, the calculation of the intramolecular electrostatic energy is revisited. These interactions are calculated between charges belonging to the different local dipoles of the molecule, one dipole being defined as a group of consecutive charges globally neutral. This new method allows avoiding the use of empirical scaling parameters commonly introduced to calculate 1-4 electrostatic interactions. The transferability of the proposed potential is demonstrated through the simulation of a wide variety of alcohol families: primary alcohols (methanol, ethanol, propan-1-ol, hexan-1-ol, octan-1-ol), secondary alcohols (propan-2-ol), tertiary alcohols (2-methylpropan-2-ol), phenol, and diols (1,2-ethanediol, 1,3-propanediol, 1,5-pentanediol). Monte Carlo simulations carried out in the Gibbs ensemble lead to a good agreement between calculated and experimental data for the thermodynamic properties along the liquid/vapor saturation curve, for the critical point coordinates and for the liquid structure at room temperature. Additional simulations were performed on the methanol + n-butane system showing the capability of the proposed potential to reproduce the azeotropic behavior of such mixtures with a good agreement. PMID:19344171

  8. 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...

  9. Thermodynamic model for predicting equilibrium conditions of clathrate hydrates of noble gases + light hydrocarbons: Combination of Van der Waals–Platteeuw model and sPC-SAFT EoS

    International Nuclear Information System (INIS)

    Highlights: • Applying sPC-SAFT for phase equilibrium calculations. • Determining Kihara potential parameters for hydrate formers. • Successful usage of the model for systems with hydrate azeotropes. - Abstract: In this communication, equilibrium conditions of clathrate hydrates containing mixtures of noble gases (Argon, Krypton and Xenon) and light hydrocarbons (C1–C3), which form structure I and II, are modeled. The thermodynamic model is based on the solid solution theory of Van der Waals–Platteeuw combined with the simplified Perturbed-Chain Statistical Association Fluid Theory equation of state (sPC-SAFT EoS). In dispersion term of sPC-SAFT EoS, the temperature dependent binary interaction parameters (kij) are adjusted; taking advantage of the well described (vapor + liquid) phase equilibria. Furthermore, the Kihara potential parameters are optimized based on the P–T data of pure hydrate former. Subsequently, these obtained parameters are used to predict the binary gas hydrate dissociation conditions. The equilibrium conditions of the binary gas hydrates predicted by this model agree well with experimental data (overall AAD P ∼ 2.17)

  10. Fluorine-18 radiofluorination of (S)-N-[(1-ethyl-2-pyrrolidinyl)methyl]-5-(3-fluoropropyl)-2,3-dimethoxybenzamide

    International Nuclear Information System (INIS)

    Substituted benzamides are selective ligands for the dopamine D2 receptors in the mammalian brain. The 5-(3-fluoropropyl) analogue of the very potent SPECT agent [123I]epidepride was shown to have the properties of a potential PET agent. Cyclotron produced H18F was delivered in 400 μL H218O into a vessel containing 1 mL of K2CO3/Kryptofix [222] in 96:4 acetonitrile/water. The H218O was removed by azeotropic distillations with acetonitrile to give K+/[K222]18F as an oil. [18F]Fluoropropylepidepride 2 was prepared by adding 5 mg of the corresponding tosylate 1 in 1 mL of acetonitrile. The reaction was allowed to proceed at 88 degree C for 24 min. Unreacted 18F was removed by eluting the reaction mixture through a silica Sep-Pak with ether. The ether was evaporated and the crude product was dissolved in 100 μL of 50:50 acetonitrile/ethanol. HPLC purification gave radiochemically pure 2

  11. 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.

  12. 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. PMID:25956185

  13. New fluid for high temperature applications

    Energy Technology Data Exchange (ETDEWEB)

    Riva, M.; Flohr, F. [Solvay Fluor GmbH, Hannover (Germany); Froeba, A.P. [Lehrstuhl fuer Technische Thermodynamik (LTT), Univ. Erlangen (Germany)

    2006-12-15

    As a result of the worldwide increased consumption of energy, energy saving measures come more and more in the focus of commercial acting. Besides the efficiency enhancement of energy consuming systems the utilization of waste heat is an additional possibility of saving energy. Areas where this might be feasible are geothermal power plants, local combined heat and power plants, solar-thermal-systems and high temperature heat pumps (HTHP). All these applications need a transfer fluid which secures the transport of the energy from it's source to the place where it is needed at high temperatures. The paper will start with a description or overview of promising energy sources and their utilization. The thermophysical properties of an azeotropic binary mixture of HFC-365mfc and a per-fluoro-poly-ether (PFPE) which fulfils the requirements on a high temperature working fluid are introduced in the second part of the paper. First results and practical experiences in an ORC process are shown in this context followed by an estimation regarding the saved energy or the improved efficiency respectively for other applications The paper will end with a brief outlook on possible new applications e.g. autarkic systems or immersion cooling of electrical parts. (orig.)

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

    International Nuclear Information System (INIS)

    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 ΔGo, ΔHo and ΔSo 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.

  15. 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.

  16. TEST REPORT #33: Compressor Calorimeter Test of R-410A Alternative: R-32/R-134a Mixture Using a Scroll Compressor

    Energy Technology Data Exchange (ETDEWEB)

    Shrestha, Som [ORNL; Sharma, Vishaldeep [ORNL; Abdelaziz, Omar [ORNL

    2014-02-18

    This report investigates the tested performance of lower - GWP candidate refrigerant, 94.07 wt% R - 32 + 5.93 wt % R - 134 a mixture (hereafter referred to as R - 32/134a), as an alternative to baseline refrigerant R - 410 A using a 36,000 Btu/hr compressor calorimeter located at the Heat Exchanger Advanced Testing Facility at Oak Ridge National Laboratory . These tests were conducted during May and August 2013. R - 410A is a near - azeotropic blend of R - 32 and R - 125 with 0.5/0.5 mass fraction and has a GWP 100 of 2100. R - 32 and R - 134a are pure refrigerants and have GWP 100 of 716 and 1370 1, respectively. Based on the GWP 100 values of pure refrigerants and their mass fraction in the blend, GWP 100 of R - 32/134a, which is under development by National Refrigerant, is 755. This report compares various performance parameters, such as cooling capacity, compressor power, refrigerant mass flow rate, EER, isentropic efficiency and discharge temperature of the alternative refrigerant to that of R - 410 A.

  17. 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.

  18. 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.

  19. Analysis of divided-wall column for extractive distillation; Suichoku bunkatsugata chushutsu joryuto ni kansuru kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Midori, S.; Zheng, S.N.; Yamada, I. [Kyowa Yuka Co., Ltd., Mie (Japan). Yokkaichi Factory

    2000-09-10

    The divided-wall column (hereinafter called DWC) has received widespread attention in terms of its compact structure and high thermal efficiency, which offers savings in capital and energy costs, since it was originally reported by Wright and Elizabeth i 1949. Some DWCs, have already been commercialized successfully including that of the authors in 1996. However, with the existing DWC construction, they cannot be applied to the separation of azeotropic systems or close boiling component systems, and the application has been limited to ordinary ternary systems, i. e. the separation of light, middle, and heavy fractions. In this paper, a new extractive distillation column that the concept of DWC can be applied to is shown, and a comparison with the conventional two-column sequence has been presented in terms of process compactness and heat integration. The devised column here is called DWC-E, and it has the following features: (1) DWC-E is divided from the column top to the midportion between the feed plate and the bottom by a vertical wall (splitting plate), and (2) DWC-E is compact-type process with only two top condensers and one reboiler. Moreover, a simulation of acetone-methanol-water extractive distillation is carried out to examine the validity of DWC-E. The result shows that DWC-E can save a maximum of 36 % energy consumption compared to the conventional two-column sequence. (author)

  20. 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

  1. Optimal Process of Extractive Distillation for Separation of Ethanol-Tetrahydrofuran with Ethylene Glycol%乙二醇萃取精馏分离乙醇-四氢呋喃的最优工艺

    Institute of Scientific and Technical Information of China (English)

    王英龙; 张青; 马羽红; 李鑫; 刘兴振

    2015-01-01

    对乙二醇萃取精馏分离乙醇-四氢呋喃共沸体系的工艺基于年度总费用最小进行了优化设计。采用设计规定与序贯迭代优化程序考察了双塔萃取精馏工艺与三塔萃取精馏工艺的经济性。结果表明,最优方案与原料组成有关,当四氢呋喃摩尔分数小于37%时,采用三塔萃取精馏工艺最优;当四氢呋喃摩尔分数大于37%时,采用双塔萃取精馏工艺最优。%Optimized design was conducted for separation of ethanol-tetrahydrofuran azeotropic system using ethylene glycol as extracting agent based on the minimized total annual cost(TAC).Design specification and procedure of sequential iterative optimization were used to investigate the economical efficiency of extractive dis-tillation process with two towers or three towers.Results showed that the optimal scheme was related to the composition of raw materials.Extractive distillation process of three towers was the optimal case when the mo-lar fraction of tetrahydrofuran was lower than 37%.Extractive distillation process of two towers should be a-dopted for molar fraction of tetrahydrofuran above 37%.

  2. 自复叠热泵冷凝器设计%Condenser Design of Auto-cascade Heat Pump

    Institute of Scientific and Technical Information of China (English)

    芮胜军; 卢向华; 梁坤峰; 李健

    2013-01-01

    与传统单级压缩式热泵相比较,非共沸混合工质自复叠热泵具有工作温差大的优点,可以扩大单级热泵的工作温度范围,适合于中国北方比较寒冷地区以及需要高温热泵的情况.以自复叠热泵系统用套管式冷凝器为研究对象,重点研究其冷凝过程特性和结构尺寸.分析了混合制冷工质泡点温度和露点温度以及气液相平衡关系,计算了套管式冷凝器的冷凝负荷.根据混合工质和冷却水的换热系数,对套管式冷凝器进行了结构尺寸确定.%Compared with the traditional single stage compressive heat pump, non-azeotropic mixture auto-cascade heat pump has the advantage of large temperature difference. It can expand temperature range of single-stage heat pump. Auto-cascade heat pump is suitable for China' s northern cold areas and the case of high temperature heat pump. The condensation process characteristics and structure size of the double-pipe condenser with auto-cascade heat pump system were studied. The mixed refrigerant bubble point temperature, dew point temperature and vapor-liquid phase equilibrium relationship were analyzed. The condensing loads of condenser were calculated. According to the heat transfer coefficient of mixed refrigerant and cooling water,the structure size of double-pipe condenser was determined.

  3. 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.

  4. 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.

  5. [18F]FMeNER-D2: Reliable fully-automated synthesis for visualization of the norepinephrine transporter

    International Nuclear Information System (INIS)

    Purpose: In neurodegenerative diseases and neuropsychiatric disorders dysregulation of the norepinephrine transporter (NET) has been reported. For visualization of NET availability and occupancy in the human brain PET imaging can be used. Therefore, selective NET-PET tracers with high affinity are required. Amongst these, [18F]FMeNER-D2 is showing the best results so far. Furthermore, a reliable fully automated radiosynthesis is a prerequisite for successful application of PET-tracers. The aim of this work was the automation of [18F]FMeNER-D2 radiolabelling for subsequent clinical use. The presented study comprises 25 automated large-scale syntheses, which were directly applied to healthy volunteers and adult patients suffering from attention deficit hyperactivity disorder (ADHD). Procedures: Synthesis of [18F]FMeNER-D2 was automated within a Nuclear Interface Module. Starting from 20–30 GBq [18F]fluoride, azeotropic drying, reaction with Br2CD2, distillation of 1-bromo-2-[18F]fluoromethane-D2 ([18F]BFM) and reaction of the pure [18F]BFM with unprotected precursor NER were optimized and completely automated. HPLC purification and SPE procedure were completed, formulation and sterile filtration were achieved on-line and full quality control was performed. Results: Purified product was obtained in a fully automated synthesis in clinical scale allowing maximum radiation safety and routine production under GMP-like manner. So far, more than 25 fully automated syntheses were successfully performed, yielding 1.0–2.5 GBq of formulated [18F]FMeNER-D2 with specific activities between 430 and 1707 GBq/μmol within 95 min total preparation time. Conclusions: A first fully automated [18F]FMeNER-D2 synthesis was established, allowing routine production of this NET-PET tracer under maximum radiation safety and standardization

  6. 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.

  7. Uphill diffusion in multicomponent mixtures.

    Science.gov (United States)

    Krishna, Rajamani

    2015-05-21

    Molecular diffusion is an omnipresent phenomena that is important in a wide variety of contexts in chemical, physical, and biological processes. In the majority of cases, the diffusion process can be adequately described by Fick's law that postulates a linear relationship between the flux of any species and its own concentration gradient. Most commonly, a component diffuses down the concentration gradient. The major objective of this review is to highlight a very wide variety of situations that cause the uphill transport of one constituent in the mixture. Uphill diffusion may occur in multicomponent mixtures in which the diffusion flux of any species is strongly coupled to that of its partner species. Such coupling effects often arise from strong thermodynamic non-idealities. For a quantitative description we need to use chemical potential gradients as driving forces. The transport of ionic species in aqueous solutions is coupled with its partner ions because of the electro-neutrality constraints; such constraints may accelerate or decelerate a specific ion. When uphill diffusion occurs, we observe transient overshoots during equilibration; the equilibration process follows serpentine trajectories in composition space. For mixtures of liquids, alloys, ceramics and glasses the serpentine trajectories could cause entry into meta-stable composition zones; such entry could result in phenomena such as spinodal decomposition, spontaneous emulsification, and the Ouzo effect. For distillation of multicomponent mixtures that form azeotropes, uphill diffusion may allow crossing of distillation boundaries that are normally forbidden. For mixture separations with microporous adsorbents, uphill diffusion can cause supra-equilibrium loadings to be achieved during transient uptake within crystals; this allows the possibility of over-riding adsorption equilibrium for achieving difficult separations. PMID:25761383

  8. Numerical analysis of an air condenser working with the refrigerant fluid R407C

    International Nuclear Information System (INIS)

    As CFC (clorofluorocarbon) and HCFC (hydrochlorofluorocarbon) refrigerants which have been used as refrigerants in a vapour compression refrigeration system were know to provide a principal cause to ozone depletion and global warming, production and use of these refrigerants have been restricted. Therefore, new alternative refrigerants should be searched for, which fit to the requirements in an air conditioner or a heat pump, and refrigerant mixtures which are composed of HFC (hydrofluorocarbon) refrigerants having zero ODP (ozone depletion potential) are now being suggested as drop-in or mid-term replacement. However also these refrigerants, as the CFC and HCFC refrigerants, present a greenhouse effect. The zeotropic mixture designated as R407C (R32/R125/R134a 23/25/52% in mass) represents a substitute of the HCFC22 for high evaporation temperature applications as the air-conditioning. Aim of the paper is a numerical-experimental analysis for an air condenser working with the non azeotropic mixture R407C in steady-state conditions. A homogeneous model for the condensing refrigerant is considered to forecast the performances of the condenser; this model is capable of predicting the distributions of the refrigerant temperature, the velocity, the void fraction, the tube wall temperature and the air temperature along the test condenser. Obviously in the refrigerant de-superheating phase the numerical analysis becomes very simple. A comparison with the measurements on an air condenser mounted in an air channel linked to a vapour compression plant is discussed. The results show that the simplified model provides a reasonable estimation of the steady-state response and that this model is useful to design purposes

  9. 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.

  10. 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.

  11. Experimental comparison of R22 with R417A performance in a vapour compression refrigeration plant subjected to a cold store

    International Nuclear Information System (INIS)

    In this paper, the performances of a vapour compression refrigeration plant using as working fluids R22 and its substitute R417A (R125/R134a/R600, 46.6/50/3.4% in mass) are experimentally studied. This type of plant is applied to a commercially available cold store, generally adopted for preservation of foodstuff. Its working is regulated by on/off cycles of the compressor, operating at the nominal frequency of 50 Hz, imposed by the classical thermostatic control. The problems related to the replacement of the fully halogenated chlorofluorcarbons (CFCs) and of the partially halogenated (HCFCs) have been only partially solved. As for R22, there is no unanimous solution for its substitution. In this paper, the refrigerant fluid experimentally tested as a substitute for R22 is the non-azeotropic mixture R417A. R417A is a non-ozone depleting long term replacement for R22, which can be used in new and existing direct expansion systems using traditional R22 lubricants. R417A provides an easy solution to the legislation requirement, since it presents an ozone depletion potential equal to zero, and it does not require a change of lubricant type, equipment redesign or significant modifications. The experimental analysis has allowed the determination of the best energetic performances of R22 in comparison with those of R417A in terms of the coefficient of performance, exergetic efficiency, exergy destroyed in the plant components and other variables characterizing the refrigeration plant performance

  12. 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.

  13. 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.

  14. 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%.

  15. 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

  16. 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.

  17. 真空蒸馏技术提取土壤水实验研究%Soil water extraction using vacuum distillation technology

    Institute of Scientific and Technical Information of China (English)

    王涛; 包为民; 陈翔; 施征; 胡海英; 瞿思敏

    2009-01-01

    Four kinds of methods for soil water extraction, azeotropic, vacuum, centrifugal and zinc micro-distillation, are introduced and compared. The stable hydrogen and oxygen isotopic concentrations of the soil water from soils with high clay content and required field capacity, extracted using vacuum distillation technology with an extraction temperature of 100℃ and continuous heating for five hours, were analyzed. The results show that the percentage of soil water extraction when using the vacuum method is close to 100% under the conditions described above; some weakly bound water in the soils is extracted, making up about 0.45% of the extracted water. For clay soils with a high water content, the maximum extraction errors (isotopic differences between the extracted water and the added water) of δ(D) and δ(18O) are - 1.2% and -0.07%, respectively, and the isotopic concentrations of extracted water are lower than those of the added water.%简要介绍共沸蒸馏、真空蒸馏、离心分离、锌的微量蒸馏4种土壤水提取技术,并对其优缺点进行了比较.对黏土含量较高且达到田间持水量的土壤在提取温度为100℃、连续加热5h条件下,真空蒸馏提取土壤水进行氢氧稳定同位素分析.结果表明:真空蒸馏技术在提取温度为100℃和连续加热5h条件下,土壤水提取百分比接近100%;土壤中有部分弱束缚水被提取出来,约占提取水分的0.45%;对土壤含水量较高的黏土,δ(D)和δ(~(18)O)最大提取误差(提取的土壤水与加入水同位素的差值)分别为-1.2%和-0.07%,提取的土壤水同位素都贫化.

  18. 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

  19. Theoretical and Experimental Study on a High Temperature Heat Pump Refrigerant%一种高温热泵制冷剂的理论和实验研究

    Institute of Scientific and Technical Information of China (English)

    张于峰; 孔令腾; 于晓慧; 张彦; 高岩

    2016-01-01

    BY4 was presented as a high temperature non-azeotropic refrigerant,and its ozone depression poten-tial(ODP)was zero. Through theoretical cycle calculation comparison with other four kinds of pure refrigerant,it was concluded that the coefficient of performance(COP),unit volumetric work and condensing pressure of BY4 in the condensing temperature range(90—110,℃) were more excellent,and its thermal physical properties were also better. At the same time a high temperature heat pump unit based on BY4 refrigerant was designed to carry out a experimen-tal test,which was conducted in a transformed heat pump testing system with the evaporator inlet temperature rang-ing from 40 to 60,℃. According to the experimental results,the condenser outlet water temperature can reach as high as 110,℃,the discharge temperature and condensing pressure are moderate under this condition,when the differ-ence between the condenser outlet water temperature and the evaporator inlet temperature is less than 35,℃,COP is always higher than 3.5.%提出一种ODP为0的高温非共沸制冷剂BY4,通过与其他4种纯制冷剂的理论循环计算对比,得出BY4在冷凝温度区间(90~110,℃)的COP、单位容积功、冷凝压力方面性能优越,且热物理性质良好;同时设计了以BY4为工质的高温热泵机组,在经过改造的热泵检测系统上进行了蒸发器进水温度在40~60,℃的实验工况测试.实验结果表明:冷凝器侧最高出水温度能达到110,℃,此时排气温度和冷凝压力适中;当冷凝器侧出水温度和蒸发器侧进水温度差小于35,℃时,COP总是大于3.5.

  20. 叔丁醇与甲醇合成甲基叔丁基醚的研究%STUDY ON SYNTHESIS OF MTBE BY TERT BUTYL ALCOHOL AND METHANOL

    Institute of Scientific and Technical Information of China (English)

    杨忠梅; 朱相春; 侯磊

    2016-01-01

    介绍以叔丁醇和甲醇为原料,采用国产催化剂A催化醚化反应制MTBE,并用Aspen Plus软件模拟后续精馏分离装置的技术和工艺。采用小试装置考察了工艺条件对反应的影响。结果表明:在空速1.0 h-1、压力2.3 MPa、温度140℃、甲醇与叔丁醇摩尔比3∶1条件下,叔丁醇转化率可达79%以上,MTBE选择性可达73%以上。 Aspen Plus软件模拟结果表明,采用醇类化合物替代水作为萃取剂,能够解决叔丁醇、水的共沸问题,并将系统中的水基本脱除,能够促使主反应向右进行,有效提高叔丁醇的转化率。%The paper introduced the preparation course of MTBE with tert butyl alcohol and methanol as crude material, which adopting some domestic catalyst. Technology and process of the preparation course was simulated by Aspen Plus software, effect of the process conditions on the reaction were studied by test device. The results showed that under the following conditions such as air speed was 1. 0 h-1 , pressure was 2. 3 MPa, temperature was 140℃, ratio of metha-nol and tert butyl alcohol was 3∶1 , conversion yield of tert butyl alcohol reached higher than 79%, selectivity ratio of MTBE reached higher than 73%. Simulation results of the Aspen Plus software showed that it was feasible that azeotrope problem of tert butyl alcohol with water could be solved by adopting some alcohol substituted for water as extractant, which could promote the reaction rightward by removing water of the system, raise effectively conservation ratio of the tert butyl alcohol.

  1. Advance in Production of Acetonitrile and its Refining Process%乙腈生产及其精制工艺研究进展

    Institute of Scientific and Technical Information of China (English)

    卢英俊; 孙小方; 潘海天

    2014-01-01

    Industrial production methods of acetonitrile are classified as indirect synthesis method and direct synthesis method. According to the different raw materials used in direct synthesis method, the merits and demerits, the maturity of the processes were discussed in this paper. It can be concluded that the processes of amination-dehydrogenation of ethanol and amination-dehydration of acetic acid can be used in industrial production of acetonitrile, for which are simple, high conversion rate, good selectivity, and the acetonitrile could be purified easily. However, the propylene ammoxidation by-product method is the indirect synthesis method, which is the primary source of industrial acetonitrile. In which, the main impurities purification methods were introduced, such as hydrocyanic acid, aldehydes and ketones, oxazole, allyl alcohol, a small amount of propionitrile and water, emphases on the purification methods of water-acetonitrile azeotrope. Finally, the by-product acetonitrile refining process and the new refining process were contrasted, and the industrial development of acetonitrile was also prospected.%乙腈的工业生产分为间接法和直接合成法两类。根据原料的不同,对直接合成法中各种方法的优劣及其工艺的成熟程度进行了重点讨论,认为乙醇氨化脱氢法、乙酸氨化脱水法工艺流程简单,转化率高,选择性好,乙腈易分离提纯,最具有工业前景;间接法为丙烯氨氧化副产法,是目前工业生产乙腈的主要来源,针对其杂质种类较多等特点,分别介绍了氢氰酸、醛酮、噁唑、丙烯醇、少量丙腈和水等主要杂质的提纯方法,重点对水与乙腈共沸物的提纯做了详细阐述。最后将副产乙腈的精制工艺与新型精制工艺进行了对比,并展望了我国乙腈工业的发展未来。

  2. 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.

  3. 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

  4. Detection Analysis and System Research on Physicochemical Properties of Methanol Gasoline%甲醇汽油理化特性的检测分析与系统研究

    Institute of Scientific and Technical Information of China (English)

    张娟利; 杨天华

    2014-01-01

    As an excellent substitute fuel of vehicles, methanol gasoline has exhibited extremely broad market space and great potential for development. In this paper,the distillation range, air-lock tendency, colloid, corrosion, stability and other physicochemical properties of the methanol gasoline were analyzed. The experimental results showed that the distillation range, air-lock tendency and colloid of the methanol gasoline were significantly influenced because of the existence of multicomponent mixture containing minimum boiling point azeotrope generated from the hydrocarbons and methyl alcohol. The certain corrosion of methanol gasoline on the engine can be restrained or eliminated by means of adding corrosion inhibitors. The stability of methanol gasoline can gradually be improved with the increasing of methanol concentration. The research can provide theoretical basis in order to resolve the problems occurred in the actual use process of methanol gasoline.%甲醇汽油作为车用燃料的有效补充,显示出广阔的市场空间和巨大的发展潜力。依次对甲醇汽油的馏程、气阻倾向、胶质、腐蚀性以及抗相分离性能等理化特性进行了系统分析,实验结果表明,汽油中的烃类物质与甲醇在不同浓度下可形成多元最低共沸物,显著影响甲醇汽油的馏程、气阻倾向和胶质;甲醇汽油对发动机的腐蚀性可通过腐蚀抑制剂的加入而减缓或消除。随着甲醇浓度的不断提高,甲醇汽油的抗相分离性能逐渐增强。研究结果可为解决甲醇汽油实际使用的问题奠定理论依据。

  5. Quantification of groundwater recharge through application of pilot techniques in the unsaturated zone.

    Science.gov (United States)

    Kallioras, Andreas; Piepenbrink, Matthias; Schuth, Christoph; Pfletschinger, Heike; Dietrich, Peter; Koeniger, Franz; Rausch, Randolf

    2010-05-01

    Accurate determination of groundwater recharge is a key issue for the "smart mining" of groundwater resources. Groundwater recharge estimation techniques depend on the investigated hydrologic zone, and therefore main approaches are based on (a) unsaturated zone, (b) saturated zone and (c) surface water studies. This research contributes to the determination of groundwater recharge by investigating the infiltration of groundwater through the unsaturated zone. The investigations are conducted through the application of a combination of different pilot field as well as lab techniques. The field techniques include the installation of specially designed Time Domain Reflectometry (TDR) sensors, at different depths within the unsaturated zone for in-situ and continuous measurements of the volumetric pore water content. Additionally, the extraction of pore water -for analysis of its isotopic composition- from multilevel undisturbed soil samples through significant depths within the unsaturated zone column, enables the dating of the groundwater age through the determination of its isotopic composition. The in-situ investigation of the unsaturated zone is complemented by the determination of high resolution temperature profiles. The installation of the pilot TDR sensors is achieved by using direct push methods at significant depths within the unsaturated zone, providing continuous readings of the soil moisture content. The direct push methods are also ideal for multilevel sampling of undisturbed -without using any drilling fluids which affect the isotopic composition of the containing pore water- soil and consequent extraction of the included pore water for further isotopic determination. The pore water is extracted by applying the method of azeotropic distillation; a method which has the least isotopic fractionation effects on groundwater samples. The determination of different isotopic signals such as 18O, 2H, 3H, and 36Cl, aims to the investigation of groundwater transit

  6. 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。

  7. Determination of the δ2H and δ18O of soil water and water in plant matter; RSIL lab code 1700

    Science.gov (United States)

    Revesz, Kinga M.; Buck, Bryan; Coplen, Tyler B.

    2012-01-01

    The purpose of the Reston Stable Isotope Laboratory lab code 1700 is to determine the δ2H/1H), abbreviated as δ2H, and the δ18O/16O), abbreviated as δ18O, of soil water and water in plant matter. This method is based on the observation that water and toluene form an azeotropic mixture at 84.1 °C. This temperature is substantially lower than the boiling points of water (100 °C) and toluene (110 °C), but water and toluene are immiscible at ambient temperature. The water content of a soil or plant is determined by weighing, drying, and reweighing a small amount of sample. Sufficient sample to collect 3 to 5 milliliters of water after distillation is loaded into a distillation flask. Sufficient toluene is added so that the sample is immersed throughout the entire distillation to minimize evaporation of water, which would affect the δ2H and δ18O values. The mixture of sample and toluene is heated in a flask to its boiling point (84.1 °C) so that water from the sample and toluene can distill together into a specially designed collection funnel. The temperature of 84.1 °C is maintained until the water has been quantitatively transferred to the collection funnel, at which time the temperature is raised to the boiling point of the remaining component (toluene, 110 °C). The collection funnel is maintained at ambient temperature so that the sample water and toluene can be separated physically. After separation, the sample water is purified by addition of paraffin wax to the container with the sample water, capping the container, and heating to approximately 60 °C to melt the wax. Trace amounts of toluene will dissolve in the wax, purifying the sample water for isotopic analysis. The isotopic composition of the purified water is then determined by equilibration with gaseous hydrogen or carbon dioxide, followed by dual-inlet isotope-ratio mass spectrometry. Because laser-absorption spectrometry is sensitive to organic compounds, such as trace toluene remaining in

  8. Polimerizacija, toplinska stabilnost i mehanizam razgradnje kopolimera (metakril-dicikloheksiluree i (metakril-diizopropiluree sa stirenom i α-metilstirenom (Polymerization, Thermal Stability and Degradation Mechanism of (Methacryl-Dicyclohexylurea and (Methacryl-Diisopropylurea Copolymers with Styrene and α-Methylstyrene

    Directory of Open Access Journals (Sweden)

    Vuković, R.

    2006-05-01

    Full Text Available This paper describes the polymerization of N-acryl-N,N'-dicyclohexylurea (A-DCU, N-methacryl- N,N'-dicyclohexylurea (MA-DCU and N-methacryl-N,N'-diisopropylurea (MA-DiPrU monomers with styrene (St and α-methylstyrene (α-MeSt, thermal stability and degradation mechanism of prepared copolymers. Free-radical initiated polymerization was performed to low conversion by using dibenzoyl peroxyde (Bz2O2 in butanone at 70 °C under nitrogen stream. It was found that the pendant group in (methacrylic monomers have high influence to the polymerization as well as to the copolymer properties. A-DCU readily homopolymerized and copolymerized with St and r1,A-DCU = 0.72 and r2,α-MeSt= 0.07, while MA-DCU does not homopolymerized or copolymerized with α-MeSt under the same conditions, but copolymerized with St to randomly composed copolymers after a long heating of comonomers. Copolymers A-DCU with α-MeSt prepared under different monomer-to monomer-ratios in the feed have random composition with an azeotropic point at ratio of 0.75 (A-DCU to 0.25 (St. The initial rate of copolymerization indicates that the rate increases almost linearly with the increase of ratio of A-DCU in the comonomer feed. Reactivity ratios determined by the Kelen-Tüdös method are: r1,A-DCU = 0.72 and r2,α-MeSt = 0.07. Molar mass of copolymers increased from 8.5 to 30 (kg mol-1 when mole ratio of A-DCU to α-MeStin the feed increased from 0.1 to 0.9. Poly(A-DCU and copolymers with α-MeSt decomposed by two-step mechanism. Under TGA (nitrogen,10 °C min-1 conditions in the first step between 180 °C and 250 °C a quantitative yield of cyclohexylisocyanate (C6H11NCO separated by a decomposition of dicyclohexylurea (DCU. The thermally stable residue represented poly(acryl-cyclohexylamide, poly(A-CHA, and copolymer with α-MeSt, poly(A-CHA-co-α-MeSt. Glass transition temperature (Tg of poly(A-DCU was at 184 °C and Tg of residue, poly(A-CHA, was at 161 °C. Tg's of the copolymers are

  9. Simulation study of the methylal purification by extractive distillation with DMF%DMF萃取精馏精制高纯度甲缩醛的模拟研究

    Institute of Scientific and Technical Information of China (English)

    张于弛

    2012-01-01

    甲缩醛是一种重要的化工原料,是由甲醇和甲醛反应生成,由于甲缩醛和甲醇存在共沸,普通精馏难以提纯至99%以上,需采用特殊精馏加以分离.N,N-二甲基甲酰胺(DMF)是一种高沸点的含氮类有机溶剂,通过氢键与甲醇形成络合物降低甲醇的挥发度,提高甲缩醛对甲醇的相对挥发度,从而使甲缩醛和甲醇较易分离.本文利用化工流程模拟软件Aspen Plus采用萃取精馏,以DMF为萃取剂,对甲缩醛生产中的产品精制进行了模拟计算,详细分析了萃取精馏塔理论板数、进料位置、溶剂比和回流比对产品浓度的影响,结果表明,最优工艺方案为:理论板数30,甲缩醛进料位置23,萃取剂进料位置4,溶剂比1.0,回流比1.8,塔顶产品甲缩醛含量达到99.9%,为分离过程的优化操作和设计提供依据.%The methylal is an important chemical material, which is reacted by methanol and formaldehyde. Ordinary distillation is difficult to be purified to more than 99%, because methylal and methanol can form azeotrope. So they require the use of special distillation to be separated. N,N-dimethyl fonnamide (DMF) is a high boiling point of nitrogen-containing organic solvent, which reduces the volatility of methanol through hydrogen bonds with methanol to form complexes. Accordingly it improves methylal the relative volatility of methanol accordingly, which make methylal and methanol easier separation. In this paper, the process simulation software, Aspen Plus was used to simulate the extractive distillation in the process of methylal purification, and DMF was used as extractive agent The influence of theory stage, feed location, ratio of extractive agent and reflux ratio on the methylal purification were detailed analyzed. The results showed the optimal condition: the number of theory plates is 30, the DMF feed location was at 4# plate, the methylal feed location was at 23# plate, the ratio of extractive agent was 1.0, reflux

  10. 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

  11. THE PREPARATION OF PROPYLENE OXIDE BY PROPYLENE EPOXIDATION WITH HYDROGEN PEROXIDE IN 1.0 kt/a PILOT PLANT%1.0 kt/a丙烯与双氧水环氧化制备环氧丙烷的中试研究

    Institute of Scientific and Technical Information of China (English)

    林民; 李华; 王伟; 龙军

    2013-01-01

    在实验室研究、小试和侧线试验的基础上,建立1.0 kt/a丙烯与双氧水环氧化制备环氧丙烷的中试装置.采用空心钛硅分子筛改性制备的丙烯环氧化催化剂HPO-1,在一定的反应压力和丙烯与双氧水摩尔比的条件下,考察反应温度、甲醇与双氧水的摩尔比和双氧水空速等对双氧水转化率和环氧丙烷选择性的影响,确定中试工艺条件为:反应温度30~70℃,反应压力0.5~2.0 MPa,双氧水质量空速0.12~1.20 h-1,甲醇与双氧水的摩尔比5~25,丙烯与双氧水的摩尔比1.2~2.5.在该条件下,运行超过6 000 h,双氧水转化率为96%~99%,环氧丙烷选择性为96%~98%,催化活性未明显下降;采用双共沸蒸馏工艺分离提纯的环氧丙烷产品的纯度不小于99.97%.%The environmental friendly preparation process of propylene oxide (PO) by propylene epoxidation with hydrogen peroxide was studied.Based on the results of basic research, laboratory test and side-line testing, a 1.0 kt/a pilot plant was built for PO preparation by epoxidation of propylene with hydrogen peroxide.Factors influencing the conversion of hydrogen peroxide and PO selectivity were investigated on pilot plant, using HPO-1 catalyst containing modified hollow titanium silicalite molecular sieve.The process conditions of pilot plant test were confirmed, in which the reaction temperature is 30-70 ℃ , the WHSV of hydrogen peroxide is 0.12-1.20 h-1 , the molar ratios of methanol to hydrogen peroxide and propylene to hydrogen peroxide are 5-25 and 1.2-2.5, respectively.Running under such conditions for more than 6 000 h, the decrease of catalyst activity is nonsignificant, the conversion of hydrogen peroxide is 96%-99% and the PO selectivity is 96%-98%.By separating with dual azeotropic distillation process and purification, the purity of PO product is more than 99.97%.

  12. Surface modified carbon nanoparticle papers and applications on polymer composites

    Science.gov (United States)

    Ouyang, Xilian

    a tensile strength of 360 MPa and an electrical conductivity of 4.45x104 S/m, much better than any similar materials reported in the literature. However, they didn't show good gas barrier properties. Since the GO paper presented zero gas permeability for both CO2 and H2, a hybrid paper fabrication approach was proposed to combine the advantages of individual GP and GO papers. This was done by filtering GP and GO layer by layer with GO sandwiched in between two layers of GP. The resulting hybrid papers showed high mechanical tensile strength and EMI shielding effectiveness that are close to GP nanopapers, and excellent gas barrier properties that comparable to GO nanopapers. The GP, GO and GP-Go-GP hybrid nanopapers have been successfully coated onto the thermoplastic surface by thermal lamination and injection molding. In the third part, the effect of PANI-CNF nanopapers and a chelating agent, 2, 4- Pentanedione (2, 4-P) on kinetics of an in-mold coating (IMC) resin was investigated. The results showed that the presence of amine functionalized carbon nanoparticles tended to retard the resin reaction, while 2, 4-P was capable of promoting the redox based free radical polymerization by forming a complex with the cobalt promoter in the initiation step. In order to understand the chemical and physical changes during the resin curing process, kinetics study on two major resin components, i.e. hexanediol diacrylate (HDDA) and styrene (St), were carried out using an integrated analysis design: differential scanning calorimetry (DSC) for overall reaction, Fourier transform infrared spectroscopy (FTIR) for individual component reactions, and rheometry for liquid-solid transition during the reaction. The gel point of this radical polymerization resin system was found to be <2% which implied that most curing was conducted in the solid phase. The results showed that the double bonds in acrylates and St followed an azeotropic polymerization pattern.

  13. 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

  14. 纳米级钇稳定氧化锆的制备与电性能表征%Preparation and Electronic Properties of Nanometer YSZ

    Institute of Scientific and Technical Information of China (English)

    彭冉冉; 夏长荣; 杨蔚光; 彭定坤; 孟广耀

    2001-01-01

    :以共沸蒸馏过程辅助的化学方法制备了纳米级的钇稳定氧化锆(YSZ)粉体.结 果表明共沸蒸馏的方法有效地实现了沉淀的完全脱水,从而阻止了颗粒问的硬团聚. X射线衍射研究指出共沉淀物转变为立方相的最低温度为600℃.X射线衍射谱和高 分辨透射电镜照片均显示在600℃下灼烧得到的粉体的粒径为6nm,而由BET比表面 积测定计算所得到的粉体粒径则为11nm,从而确定团聚为软团聚.YSZ样片在 1500℃下烧结5h得到了相对密度为94.8%的烧结体.以交流阻抗谱技术研究在空气 和氩气气氛中材料的电导率,在900℃空气气氛下测得的电导率为0.056S·cm-1,而 在氩气气氛下可达到0.067S·cm-1,显著高于用单纯共沉淀法制备的YSZ样片的电 导率(0.009 S·cm-1)及用Plaster casting法制备的电导率(0.028S·cm-1).而电导活化 能为0.88-0.89eV,较文献报导值低.%Nanoscale yttria doped zirconia powders are prepared by coprecipitation route aided by the azeotropic distillation process. As a result, hydrous zirconia are dehydrated effectively and the forma tion of hard agglomerates is prevented completely. Powder X-ray diffraction is carried out to testify the lowest calcination temperature for precipitate powders to turn into cubic phase with the value of 600℃. Powder X-ray diffraction, BET method and transmission electron microscopy were performed to charac terize the powder properties. After being calcined at 600℃ for 2h, the average powder size was about 6nm calculated from XRD spectra and HRTEM photo, while by BET method, the powder size is about 11 m, which indicates that the aggregates are just soft aggregates. The density of YSZ pellets sintered at 1500℃ for 5h reached 94.8% and the electrical conductivity of the sintered pellets is 0. 056 S· cm-1 in air and 0.067 S· cm-1 in Ar measured at 900℃ by a. c. impedance spectroscopy much higher than the reported value[4,5].

  15. 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

  16. 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.

  17. Volatility and vehicle driveability performance of ethanol/gasoline blends. A literature review

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-10-15

    The effect of blending ethanol (up to 20% v/v) into gasoline on the volatility of the ethanol/gasoline blend and on the hot and cold weather vehicle driveability performance of these blends has been assessed from published literature. This literature review covers major fuel blending and vehicle driveability studies that have been completed over the past 20 years. The percentage of an ethanol/gasoline blend that evaporates at 70{sup o}C (E70) substantially increases when ethanol is blended into gasoline. The corresponding E100 (the percent of the blend that evaporates at 100{sup o}C) also increases but less substantially than the E70 value. The increase in these two volatility parameters with ethanol addition is usually smaller as the volatility of the gasoline increases. Interestingly, 'Blending E70' values for ethanol tend to decrease with increasing ethanol content while 'Blending E100' values increase. This difference is due to the formation of an azeotrope that affects the volatility behaviour of the ethanol/gasoline blend at different temperatures. Simple predictive models have been developed based on analytical data from the published studies that describe the change in Blending E70 and Blending E100 values with the base gasoline's E70 and E100 and with ethanol contents in the range of 5 to 20% v/v.. Published studies on the impact of ethanol and gasoline volatility on vehicle driveability performance have also been evaluated. These included seven studies on Hot Weather Driveability (HWD) and eleven studies on Cold Weather Driveability (CWD). These studies show that modern vehicles are much less susceptible to HWD performance problems than are older vehicles. Some early model Direct Injection Spark Ignition vehicles tested by CONCAWE/GFC (2003) showed some HWD problems but only on high volatility fuels. Current specification properties appear to be adequate to control HWD but some increases in the E70 maximum limits allowed by the

  18. 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

  19. Transient startup process of batch distillation in rotating packed bed%旋转填料床间歇精馏不稳态开工过程

    Institute of Scientific and Technical Information of China (English)

    陈攀攀; 阮奇; 苏宁子; 赖萍; 严佐毅

    2012-01-01

    The purpose of the study is to deeply understand the influence factors and laws of transient startup process of batch distillation in rotating packed bed(RPB) which is packed with triangular spiral packing. The batch distillation experiments were done with ethanol-water system at atmospheric pressure and under the total reflux conditions. The rotational speed ranged 450 rpm from 1050 rpm, which provided centrifugal forces a great many times than the Earth's gravity. By means of changing the feed concentration, rotational speed and heating power, experimental results indicate that the transient startup process is greatly enhanced in terms of shortening time and saving energy. The startup process in our study only needs about 30 minutes and the concentration of distillate is high(nearly the azeotropic mixture of the ethanol-water system). Comparing with the conventional column in the gravitational field, the startup process in RPB is not a time-consuming process. Consequently, the concentration of distillate which increases with the feed composition and the heating power of reboiler comes up to maximum under the optimal rotational speed. An unusual result is also noted that the startup process of batch distillation in RPB with different feed composition should operate under the higher heating power of reboiler and the corresponding optimal rotational speed conditions in practical production process. Therefore, the batch distillation transient startup process in RPB has the best effect under the optimal rotational speed and higher heating power. The results indicate that the startup process of batch distillation in RPB is greatly intensified, which places an important role in the process of product removal in terms of shortening period of operation, enhancing produce capacity and saving energy, etc. Moreover, the mathematical model based on the equilibrium stage theory was built to describe the laws of transient startup of batch distillation in RPB. The average

  20. 钛掺杂对纳米CeO2磨料硅片抛光性能的改善%Improvement on Polishing Performance for Silicon Wafer of Nano-sized Ceria Abrasives by Tianium-doping

    Institute of Scientific and Technical Information of China (English)

    傅毛生; 李永绣

    2013-01-01

    Titanium-doped ceria Ce1-xTixO2(x =0,0.1,0.2,0.3) powders were prepared via a co-precipitation method,using ethylene glycol (EG)/water as reaction mixed solvent and with precursor treatment of butanol azeotropic distillation.Moreover,the crystalline phase structure,morphology,zeta potential were characterized by X-ray diffraction(XRD),Transmission electron microscopy(TEM) and zeta potential analysis respectively.The polishing performance of the as-synthesized Ti-doped ceria abrasives for Silicon wafer was evaluated by the material removal rate (MRR) and atomic force microscopy (AFM).The results show that the ceria powder and Ti-doped ceria synthesized at 900℃ possesses nano-sized spheroidal morphology with a diameter of 40 ~ 50nm.A maximum MRR value of 139 nm · min-1 was obtained by using Ce0.8Ti0.2O2 nano-sized abrasives as a polishing powder for silicon wafer,and the surface roughness Ra in a 1.0μm × 1.0μm area were found to be of 0.254 nm.This MRR value is ca.2.0 times of that obtained from by using pure ceria nanoparticles (that is,67nm · min-1).However,MRR value of Ce0.9 Ti0.1O2 and Ce0.7Ti0.3O2 abrasives are 112nm · min-1 and 89nm · min-1,respectively.The facts indicate that the polishing performance for silicon wafer of nano-sized ceria abrasives is significantly improved by Titanium-doping,which closely related to the increase of the zeta potential of Ti-doped ceria and the formation of CeTi2O6.%以已二醇/水混合溶液为反应介质并结合正丁醇共沸蒸馏处理前驱体,通过化学共沉淀法制备掺钛的Ce1-xTixO2(x=0,0.1,0.2,0.3)粉体,运用X射线衍射仪(XRD)、透射电镜(TEM)、Zeta电位仪等仪器对其物相、外观形貌、表面电位等性质进行了表征,通过测定去除速率和原子力显微镜观察硅片表面的微观形貌来评价钛掺杂对CeO2磨料硅片抛光性能的影响.结果表明,900℃焙烧时所合成的CeO2及其复合氧化物为均一的纳米球状粒子,一次粒子尺寸为40 nm