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Sample records for azeotrope

  1. 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

  2. Static multiplicities in heterogeneous azeotropic distillation sequences

    DEFF Research Database (Denmark)

    Esbjerg, Klavs; Andersen, Torben Ravn; Jørgensen, Sten Bay; Müller, Dirk; Marquardt, Wolfgang

    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...... different static behavior. The method of Petlyuk and Avet'yan (1971), Bekiaris et al. (1993), which assumes infinite reflux and infinite number of stages, is extended to and applied on heterogeneous azeotropic distillation sequences. The predictions are substantiated through simulations. The static sequence...

  3. Simultaneous Design of Ionic Liquids and Azeotropic Separation Processes

    DEFF Research Database (Denmark)

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

    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. 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.

  5. On the Responses of Azeotropes to Pressure Variations

    DEFF Research Database (Denmark)

    Abildskov, Jens; O’Connell, John P.

    . 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...

  6. 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.

  7. Responses of azeotropes and relative volatilities to pressure variations

    DEFF Research Database (Denmark)

    Abildskov, Jens; O’Connell, John P.

    2015-01-01

    two columns. Because operating costs are highly sensitive to the pressure dependence of azeotropic compositions, reliable and accurate phase equilibrium thermodynamic property information is needed to computationally explore pressure variation for such processes. An analysis of property modeling has......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...... been done for the pressure sensitivity of azeotropic composition, and examples are given of modeling strategies for binary and ternary mixtures. A quantitative criterion for the need to consider nonideality effects in both modeling and parameter regression has been established, based on similarity of...

  8. 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.

  9. Ionic-Liquid Based Separation of Azeotropic Mixtures

    DEFF Research Database (Denmark)

    Kulajanpeng, Kusuma; Suriyapraphadilok, Uthaiporn; Gani, Rafiqul

    2014-01-01

    methodology for the screening of ionic liquids (ILs) as entrainers for ILs-based separation processes in binary aqueous azeotropic systems (e.g., water + ethanol and water + isopropanol) is presented. Ionic liquids as entrainers were first screened based on a combination of criteria 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...... minimum concentration of the ILs required to break the given azeotrope, the best ILs as entrainers for water + ethanol and water + isopropanol azeotropic mixtures were [C1MIM][DMP] and [C2MIM][N(CN)2], respectively....

  10. Analytical determination of distillation boundaries for ternary azeotropic systems

    OpenAIRE

    Marcilla Gomis, Antonio; Reyes Labarta, Juan Antonio; Velasco, Raúl; Serrano Cayuelas, María Dolores; Olaya López, María del Mar

    2009-01-01

    A new straight forward algorithm to calculate distillation boundaries in ternary azeotropic systems has been developed. The proposed method allows, using cubic splines, the calculation of distillation trajectories and the calculation of that corresponding to the searched distillation boundaries. The algorithm is applied to 4 ternary liquid-vapour systems to test its validity.

  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. Ionic-Liquid Based Separation of Azeotropic Mixtures

    DEFF Research Database (Denmark)

    Kulajanpeng, Kusuma; Suriyapraphadilok, Uthaiporn; Gani, Rafiqul

    2014-01-01

    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......methodology for the screening of ionic liquids (ILs) as entrainers for ILs-based separation processes in binary aqueous azeotropic systems (e.g., water + ethanol and water + isopropanol) is presented. Ionic liquids as entrainers were first screened based on a combination of criteria such as...... [C1MIM][DMP]. For the final evaluation, the best candidates for aqueous systems were used as entrainers, and then the vapor-liquid equilibrium (VLE) of the ternary systems containing ILs was predicted by the Non Random Two Liquids (NRTL) model to confirm the breaking of the azeotrope. Based on...

  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. 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......A methodology and tool set for the simultaneous design of ionic liquid entrainers and azeotropic separation processes is presented. By adjusting the cation, anion, and alkyl chain length on the cation, the properties of the ionic liquid can be adjusted to design an entrainer for a given azeotropic...

  15. Mixing properties of binary mixtures presenting azeotropes at several temperatures

    International Nuclear Information System (INIS)

    Experimental densities, speeds of sound, and refractive indices of the binary mixtures presenting azeotropes of (ethanol with hexane or heptane or 2-butanone) and (2-propanol with 2-butanone or ethylacetate or cyclohexane) were determined from T = (293.15 to 303.15) K. Excess molar volumes, changes of refractive index on mixing and deviations in isentropic compressibility for the above systems were calculated. A function of the mole fraction and temperature polynomial equation was used to fit these quantities. The standard deviations between experimental and calculated values are shown

  16. 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.

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

    DEFF Research Database (Denmark)

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

    fraction of water at the azeotrope is less than 30%. For promising ionic liquid candidates, the extractive distillation processes were designed using a reverse simulation approach and characterized in terms of the driving force (calculated from the predicted vapor-liquid equilibria) that corresponds to the...... optimal design of the separation process (in terms of number of stages, feed plate location, energy used, solvent loss, environmental impact, etc.). To ensure the feasibility of ionic liquids to be used as industrial entrainers, a correlation was also made relating molecular structure to thermal...... decomposition temperature. For any new synthesis-design problem involving aqueous azeotropes, all it now requires is to find the azeotropic composition of water and based on it, to identify an appropriate ionic liquid. Then the driving force is calculated for the azeotrope ionic liquid and based on it, the...

  18. Interference phenomena in azeotropic distillation for liquid scintillation measurement

    International Nuclear Information System (INIS)

    The Cryogenic Pilot is an experimental project in the national nuclear energy 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 in which the Cryogenic Pilot can interact with the environment: by atmospheric release and through the sewage system. In order to establish the base level of tritium concentration 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 two solvents were used, toluene and cyclohexane, and all measurements for the determination of environmental tritium concentration was 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 blank samples was between 0.926 CPM and 1.002 CPM and the counting efficiency between 25.37% and 26.10%. 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

  19. 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)

  20. 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.

  1. 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)

  2. 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

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

    Science.gov (United States)

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

    2015-01-14

    Monodisperse silver nanocages (AgNCs) with specific interiors were successfully synthesized by an azeotropic distillation (AD) assisted method and exhibited excellent catalytic activities for reduction of 4-nitrophenol (4-NP) into 4-aminophenol (4-AP) due to the unique hollow morphology and small thickness of the silver shell. PMID:25421649

  4. 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.

  5. 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.

  6. 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

  7. 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.)

  8. Efficient water removal in lipase-catalyzed esterifications using a low-boiling-point azeotrope.

    Science.gov (United States)

    Yan, Youchun; Bornscheuer, Uwe T; Schmid, Rolf D

    2002-04-01

    High conversions in lipase-catalyzed syntheses of esters from free acyl donors and an alcohol requires efficient removal of water preferentially at temperatures compatible to enzyme activity. Using a lipase B from Candida antarctica (CAL-B)-mediated synthesis of sugar fatty-acid esters, we show that a mixture of ethyl methylketone (EMK) and hexane (best ratio: 4:1, vo/vo) allows efficient removal of water generated during esterification. Azeotropic distillation of the solvent mixture (composition: 26% EMK, 55% hexane, 19% water) takes place at 59 degrees C, which closely matches the optimum temperature reported for CAL-B. Water is then removed from the azeotrope by membrane vapor permeation. In case of glucose stearate, 93% yield was achieved after 48 h using an equimolar ratio of glucose and stearic acid. CAL-B could be reused for seven reaction cycles, with 86% residual activity after 14 d total reaction time at 59 degrees C. A decrease in fatty-acid chain length as well as increasing temperatures (75 degrees C) resulted in lower conversions. In addition, immobilization of CAL-B on a magnetic polypropylene carrier (EP 100) facilitated separation of the biocatalyst. PMID:11857278

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. Thermodynamic investigation on the azeotropic mixture composed of water + n-propanol + benzene

    International Nuclear Information System (INIS)

    Molar heat capacity of the azeotropic mixture composed of water, n-propanol, and benzene was measured by an adiabatic calorimeter from 79 to 320 K. The glass transition and melting processes of the mixture were determined based on the curve of the heat capacity with respect to temperature. The glass transition occurred at 101.920 K. The melting processes took place in temperature ranges 258-268 and 268-279 K. The corresponding melting enthalpies and entropies were calculated to be 1.474 kJ mol-1, 5.508 J K-1 mol-1; 6.144 kJ mol-1, 22.28 J K-1 mol-1, respectively. The thermodynamic functions and the excess thermodynamic functions of the mixture relative to 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

  14. 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.

  15. 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

  16. 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 ℃.

  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. 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.

  19. Low-temperature heat capacity of the azeotropic mixture composed of water+ethanol+benzene

    International Nuclear Information System (INIS)

    Molar heat capacity of the azeotropic mixture composed of water, ethanol, and benzene was measured by an adiabatic calorimeter from 80 to 320 K. The glass transition and phase transitions of the mixture were determined based on the curve of the heat capacity with respect to temperature. The glass transition occurred at 102.850 K. The phase transitions took place in temperature ranges 140-155 K and 265-280 K corresponding to the solid-liquid phase transitions of ethanol, water and benzene, respectively. The corresponding enthalpies and entropies of the phase transition were calculated to be 0.4157 kJ mol-1, 2.824 J K-1 mol-1; 1.293 kJ mol-1, 4.692 J K-1 mol-1; 4.876 kJ mol-1, 17.67 J K-1 mol-1; respectively. The thermodynamic functions and the excess thermodynamic functions of the mixture relative to 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

  20. 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.

  1. Cation effect of ammonium imide based ionic liquids in alcohols extraction from alcohol-alkane azeotropic mixtures

    International Nuclear Information System (INIS)

    Highlights: • Six ternary liquid+liquid equilibriums alkane + alcohol + IL were studied. • The influence of IL cation structure was evaluated. • The ethanol extraction ability from alkanes was determined for each IL. • Determination of solute distribution ratio and selectivity was required. • Experimental data correlation was realized by NRTL model. -- Abstract: During recent last years, outstanding properties of ionic liquids such as low melting point, large liquid range and negligible volatility have turned them into possible volatile organic solvents replacers to break alcohol-alkane azeotropic mixtures. On this basis, two ionic liquids, butyltrimethylammoniumbis(trifluoromethylsulfonyl)imide, [BTMA][NTf2], and tributylmethylammoniumbis(trifluoromethylsulfonyl)imide, [TBMA][NTf2], were studied through ternary liquid+liquid equilibrium (LLE) of {alkane(1) + alcohol (2) + IL(3)} at T = 298.15 K and atmospheric pressure in order to consider the effect of ionic liquid cation alkyl chain length on the extraction process. The ILs capability as azeotrope breakers was determined by the calculation of parameters such as solute distribution ratio, β, and selectivity, S and this capability was compared with other bis (trifluoromethylsulfonyl)imide based ionic liquids from literature. The consistency of tie-line data was ascertained by applying the Othmer–Tobias and Hand equations. Finally, the experimental LLE were correlated by the Non Random Two Liquid (NRTL) thermodynamic model

  2. 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.

  3. 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...

  4. 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

  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. 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...

  7. 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.

  8. Improving the (18)F-fluoromethylcholine ((18)F-FCH) radiochemical yield via optimising the azeotropic drying of non-carrier-added (18)F-fluorine.

    Science.gov (United States)

    Hassan, Hishar; Abu Bakar, Suharzelim; Halim, Khairul Najah Che A; Idris, Jaleezah; Ahmad Saad, Fathinul Fikri; Nordin, Abdul Jalil

    2015-01-01

    (18)F-Fluoromethylcholine ((18)F-FCH) has been suggested as one of the reputable imaging tracers for diagnosis of prostate tumour in PET/CT examination. Nevertheless, it has never been synthesised in Malaysia. We acknowledged the major problem with (18)F-FCH is due to its relatively low radiochemical yield at the end of synthesis (EOS). Therefore, this technical note presents improved (18)F-FCH radiochemical yields after carrying out optimisation on azeotropic drying of non-carrier-added (18)F-Fluorine. PMID:26395258

  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. Dehydration of an azeotrope of ethanol/water by sodium carboxymethylcellulose membranes cross-linked with organic or inorganic cross-linker

    Directory of Open Access Journals (Sweden)

    2010-11-01

    Full Text Available To control the swelling of sodium carboxymethylcellulose (CMCNa membranes, mixtures of CMCNa and glutaraldehyde (GA and mixtures of CMCNa as an organic component and tetraethoxysilane (TEOS as an inorganic component were prepared, and CMCNa/GA cross-linked membranes and CMCNa/TEOS hybrid membranes were formed. In the separation of an ethanol/water azeotrope by pervaporation (PV, the effects of the GA or TEOS content on the water/ethanol selectivity and permeability of these CMCNa/GA cross-linked and CMCNa/TEOS hybrid membranes were investigated. Cross-linked and hybrid membranes containing up to 10 wt% GA or 10 wt% TEOS exhibited higher water/ethanol selectivity than CMCNa membrane without any cross-linker. This resulted from both increased density and depressed swelling of the membranes by the formation of a cross-linked structure. The relationship between the structure of the CMCNa/GA cross-linked membranes and CMCNa/TEOS hybrid membranes and their permeation and separation characteristics for an ethanol/water azeotrope during PV is discussed in detail.

  11. 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...

  12. 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.

  13. 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.

  14. 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.

  15. 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。

  16. 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

  17. Improvement of Batch Distillation Separation of Azeotropic Mixtures

    OpenAIRE

    Hegely, Laszlo

    2013-01-01

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

  18. 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 ...

  19. 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.

  20. 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...

  1. 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...

  2. Validating the Equilibrium Stage Model for an Azeotropic System in a Laboratorial Distillation Column

    Science.gov (United States)

    Duarte, B. P. M.; Coelho Pinheiro, M. N.; Silva, D. C. M.; Moura, M. J.

    2006-01-01

    The experiment described is an excellent opportunity to apply theoretical concepts of distillation, thermodynamics of mixtures and process simulation at laboratory scale, and simultaneously enhance the ability of students to operate, control and monitor complex units.

  3. Designing And Manufacture Of The Automatic Temperature Controller For Azeotropic Distillation Apparatus

    International Nuclear Information System (INIS)

    The process of establishing joint technology mark on the oil wells, Mark Technical Department of the Center for Applications of Nuclear Techniques in Industry (CANTI) have used the low carbon number alcohol like methanol (MeOH) attached 14C mark and Ethanol (EtOH) affixed 3H wells in the joint survey of rock and sand foundation. Fractional distillation technique used for separation and enrichment of alcohol. The radioactive isotope 14C and 3H in the marking compound after enrichment was analyzed by measurement of liquid scintillation counting. Mission design, installation and testing of 02 systems automatic temperature controller for distillation systems enriched tracers isotopes by the method of PID feedback control to stabilize the temperature at Isothermal, in order to increase yield by fractional distillation system enriched isotopes radioactive and stable and uniform distillation time of the distillation system, on the other hand, saving time of people who do experiments in distillation. The device includes a temperature control module integrates its PID Omron (OMRON E5CN-Q2HBT) is highly accurate and easy parameter setting right on the machine controller and displayed on the display; Solid State Relay (SSR) of the firm Omron (OMRON G3PA-210B) precision and high switching frequency, time delay for the switching process is 3ms, the large load 6A; BTA-06 triac circuit used to current controller provides heating stove; Thermocouple used with Omron's JPT 100 resolution thermal measurements from -200 to 500oC. The device can operate in two modes distilled through the switch back, the first mode is the mode of the old distillery system and mode 2 is the distillation mode automatically controls the temperature of the newly installed. Automatic temperature controller with an error in temperature for the two processes of fractional distillation is CANTI ±1oC; recovery efficiency of the two processes are analyzed to achieve > 65% for process MeOH and > 75% for the EtOH process analysis; distillation time stability for the two systems is 6 hours or 8 hours depending on the parameter settings for the current percentage of the BTA. Purpose: Designed and manufactured automatic temperature controller for distillation apparatus which enriched radioisotopes in studying produced water in the oilfield, can establish temperature for each different distillation procedures with an error of ± 1oC. (author)

  4. 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...

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

    OpenAIRE

    F. Anguebes-Franseschi; E. Bolaños-Reynoso; A. Castro-Montoya; D. Cantú-Lozano

    2004-01-01

    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 res...

  6. 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.

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

    OpenAIRE

    Beatriz A Mandagarán; Enrique A Campanella

    2008-01-01

    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 m...

  8. 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...

  9. Isopropyl alcohol recovery by heteroazeotropic batch distillation

    OpenAIRE

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

    2010-01-01

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

  10. 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)

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

    OpenAIRE

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

    2009-01-01

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

  12. 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.

  13. 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.

  14. 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…

  15. 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.

  16. Isopropanol dehydration via extractive distillation using low transition temperature mixtures as entrainers

    International Nuclear Information System (INIS)

    Highlights: • Low transition temperature mixtures (LTTMs) were used for the (isopropanol + water) separation. • (Vapor + liquid) equilibrium (VLE) data of pseudo-binary and pseudo-ternary systems were measured. • The VLE data were successfully correlated using the NRTL model. • (Glycolic acid + choline chloride) (molar ratio = 3:1) showed the largest azeotrope displacement. - Abstract: Low transition temperature mixtures (LTTMs), also known as deep eutectic solvents, show properties that make them suitable as entrainers for extractive distillation. Two different low transition temperature mixtures were considered as potential entrainers for the extractive distillation of the azeotropic mixture (isopropanol + water). (Lactic acid + choline chloride) (2:1) and (glycolic acid + choline chloride) (3:1) were selected for this work. (Vapor + liquid) equilibrium measurements of the pseudo-binary systems (isopropanol + LTTM) and (water + LTTM) were measured at different concentrations of LTTM in a pressure range of 10 to 100 kPa. (Vapor + liquid) equilibrium data of the pseudo-ternary system (isopropanol + water + LTTM) were also measured at constant pressure (100 kPa) and constant LTTM molar fraction of 0.05 and 0.1. It was found that these LTTMs cannot break the azeotrope at those concentrations. However, the azeotrope was displaced to a much higher isopropanol concentration. The NRTL model was successfully applied to fit the experimental data

  17. Synthesis and gas permeability of block copolymers composed of poly(styrene-co-acrylonitrile) and polystyrene blocks

    Czech Academy of Sciences Publication Activity Database

    Lokaj, Jan; Brožová, Libuše; Holler, Petr; Pientka, Zbyněk

    2002-01-01

    Roč. 67, č. 2 (2002), s. 267-278. ISSN 0010-0765 R&D Projects: GA ČR GA203/99/0572 Institutional research plan: CEZ:AV0Z4050913 Keywords : azeotropic styrene- acrylonitrile copolymers * block copolymers * nitroxide-mediated copolymerization Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.848, year: 2002

  18. 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.

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

    International Nuclear Information System (INIS)

    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 GE. - 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 (GE) 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 GE for all investigated temperatures over the whole composition range.

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

    DEFF Research Database (Denmark)

    Kulajanpeng, Kusuma; Suriyapraphadilok, Uthaiporn; Gani, Rafiqul

    2016-01-01

    based on a combination of criteria such as stability, toxicity, and their environmental impacts. All best ILs were used as entrainers, and an extractive distillation column (EDC) and ionic liquid recovery column were designed and simulated with a process simulator to determine the overall energy...... consumption of the ILs-based separation processes. Among all candidates, the best IL was selected based on the minimum energy requirement obtained from the simulation. Finally, the modification of the separation process to obtain design flexibility for other azeotropic series with respect to the change in...... size of the target solute was investigated using the same separation process and IL entrainer to obtain the same product purity. The proposed methodology has been evaluated through a case study of binary alcoholic aqueous azeotropic separation: water+ethanol and water+isopropanol....

  1. 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.

  2. 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.

  3. Thermodynamic functions, freezing transition, and phase diagram of dense carbon-oxygen mixtures in white dwarfs

    International Nuclear Information System (INIS)

    Equations of state for dense carbon-oxygen (C-O) binary-ionic mixtures (BIM's) appropriate to the interiors of white dwarfs are investigated through Monte Carlo simulations, by solution of relevant integral equations and variational calculations in the density-functional formalism. It is thereby shown that the internal energies of the C-O BIM solids and fluids both obey precisely the linear mixing formulas. We then present an accurate calculation of the phase diagram associated with freezing transitions in such BIM materials, resulting in a novel prediction of an azeotropic diagram. Discontinuities of the mass density across the azeotropic phase boundaries are evaluated numerically for application to a study of white-dwarf evolution

  4. Preparation of nano-sized α-Al2O3 from oil shale ash

    International Nuclear Information System (INIS)

    Oil shale ash (OSA), the residue of oil shale semi-coke roasting, was used as a raw material to synthesize nano-sized α-Al2O3. Ultrasonic oscillation pretreatment followed by azeotropic distillation was employed for reducing the particle size of α-Al2O3. The structural characterization at molecular and nanometer scales was performed using X-ray diffraction (XRD), transmission electron microscopy (TEM), respectively. The interaction between alumina and n-butanol was characterized by Fourier transform infrared spectroscopy (FT-IR). The results revealed that the crystalline phase of alumina nanoparticles was regular and the well dispersed alumina nanoparticles had a diameter of 50-80 nm. In addition, the significant factors including injection rate of carbon oxide (CO2), ultrasonic oscillations, azeotropic distillation and surfactant were investigated with respect to their effects on the size of the alumina particles.

  5. Quaternary isobaric (vapor + liquid + liquid) equilibrium and (vapor + liquid) equilibrium for the system (water + ethanol + cyclohexane + heptane) at 101.3 kPa

    International Nuclear Information System (INIS)

    Highlights: → Water-ethanol-cyclohexane-heptane and water-cyclohexane-heptane isobaric VLLE. → Isobaric experimental data were determined at 101.3 kPa. → A dynamic recirculating still with an ultrasonic homogenizer was used. → The quaternary system does not present quaternary azeotropes. - Abstract: Experimental isobaric (vapor + liquid + liquid) and (vapor + liquid) equilibrium data for the ternary system {water (1) + cyclohexane (2) + heptane (3)} and the quaternary system {water (1) + ethanol (2) + cyclohexane (3) + heptane (4)} were measured at 101.3 kPa. An all-glass, dynamic recirculating still equipped with an ultrasonic homogenizer was used to determine the VLLE. The results obtained show that the system does not present quaternary azeotropes. The point-by-point method by Wisniak for testing the thermodynamic consistency of isobaric measurements was used to test the equilibrium data.

  6. 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. PMID:27320380

  7. 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)

  8. 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)

  9. Quaternary isobaric (vapor + liquid + liquid) equilibrium and (vapor + liquid) equilibrium for the system (water + ethanol + cyclohexane + heptane) at 101.3 kPa

    Energy Technology Data Exchange (ETDEWEB)

    Pequenin, Ana; Asensi, Juan Carlos [Departamento de Ingenieria Quimica, Universidad de Alicante, Ap. 99, E-03080 Alicante (Spain); Gomis, Vicente, E-mail: vgomis@ua.es [Departamento de Ingenieria Quimica, Universidad de Alicante, Ap. 99, E-03080 Alicante (Spain)

    2011-08-15

    Highlights: > Water-ethanol-cyclohexane-heptane and water-cyclohexane-heptane isobaric VLLE. > Isobaric experimental data were determined at 101.3 kPa. > A dynamic recirculating still with an ultrasonic homogenizer was used. > The quaternary system does not present quaternary azeotropes. - Abstract: Experimental isobaric (vapor + liquid + liquid) and (vapor + liquid) equilibrium data for the ternary system {l_brace}water (1) + cyclohexane (2) + heptane (3){r_brace} and the quaternary system {l_brace}water (1) + ethanol (2) + cyclohexane (3) + heptane (4){r_brace} were measured at 101.3 kPa. An all-glass, dynamic recirculating still equipped with an ultrasonic homogenizer was used to determine the VLLE. The results obtained show that the system does not present quaternary azeotropes. The point-by-point method by Wisniak for testing the thermodynamic consistency of isobaric measurements was used to test the equilibrium data.

  10. UNIQUAC activity coefficient model for the systems of 1-propanol + water and 2-propanol + water

    OpenAIRE

    Numuang, C.; Kaewsichan, L.

    2005-01-01

    Predictions of vapor liquid equilibria and azeotrope conditions of binary systems of 1-propanol+ water and 2-propanol+water at 30, 60, and 100 kPa were conducted in this work. UNIQUAC activity coefficient and ideal gas models represented behavior of the systems in liquid phase and vapor phase respectively. Experimental data collected from the literature (Gobaldon et al., 1996 and Marzal et al., 1996) were used to calculate energy interaction parameters of the UNIQUAC activity coefficient mode...

  11. 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...

  12. 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 ...

  13. 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...

  14. 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...

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

    OpenAIRE

    Helmy, H. E.; El-Nockrashy, A. S.; El-Noamany, H. M.

    1994-01-01

    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 pr...

  16. <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.

  17. 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.

  18. Characterization of NaA-zeolite membranes using pervaporation / Nozipho Nompumelelo Mzinyane

    OpenAIRE

    Mzinyane, Nozipho Nompumelelo

    2005-01-01

    Pervaporation has gained increasing attention as an energy saving process for separating azeotropes such as ethanol and water mixtures. Pervaporation distinguishes itself from other membrane processes in that it entails a phase transition step that occurs during the diffusion through the membrane, from the liquid phase in the feed to a vapor phase in the permeate. Pervaporation performance is mainly regulated by the physicochemical structure of the membrane rather than the v...

  19. HIDiC - Design, Sensitivity and Graphical Representation

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  20. 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.

  1. 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

  2. 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....

  3. 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.)

  4. 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...

  5. Hydrogen production based on magnetic fusion

    International Nuclear Information System (INIS)

    Aspects of the work that are reported are (1) a brief summary of the status of TMR blanket design studies as an energy source for thermochemical cycles, (2) a joule-boosted decomposer concept for SO3 decomposition, and (3) some of the details of the thermodynamics of boiling of the H2SO4 azeotrope and the enthalpy of the resulting vapor as a function of temperature

  6. 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...

  7. 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.

  8. 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.)

  9. 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...

  10. 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.

  11. Drying poly(ethylene glycol)

    OpenAIRE

    sprotocols

    2015-01-01

    Authors: Lucas Kinard, Kurtis Kasper & Antonios Mikos ### Abstract This protocol describes the drying of poly(ethylene glycol) (PEG) by a simple 6 step procedure. One can implement this protocol using common lab glass and lab equipment. Water is removed from PEG by azeotropic distillation in toluene. The two components are mixed and toluene and water are distilled off by heating the solution to 170°C. This procedure can be implemented in ~2 h. ### Introduction In many ...

  12. 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)

  13. 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.

  14. 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.

  15. 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.

  16. VLE measurements using a static cell vapor phase manual sampling method accompanied with an empirical data consistency test

    International Nuclear Information System (INIS)

    Highlights: • We use a new, simple static cell vapor phase manual sampling method (SCVMS) for VLE (x, y, T) measurement. • The method is applied to non-azeotropic, asymmetric and two-liquid phase forming azeotropic binaries. • The method is approved by a data consistency test, i.e., a plot of the polarity exclusion factor vs. pressure. • The consistency test reveals that with the new SCVMS method accurate VLE near ambient temperature can be measured. • Moreover, the consistency test approves that the effect of air in the SCVMS system is negligible. - Abstract: A new static cell vapor phase manual sampling (SCVMS) method is used for the simple measurement of constant temperature x, y (vapor + liquid) equilibria (VLE). The method was applied to the VLE measurements of the (methanol + water) binary at T/K = (283.2, 298.2, 308.2 and 322.9), asymmetric (acetone + 1-butanol) binary at T/K = (283.2, 295.2, 308.2 and 324.2) and two-liquid phase forming azeotropic (water + 1-butanol) binary at T/K = (283.2 and 298.2). The accuracy of the experimental data was approved by a data consistency test, that is, an empirical plot of the polarity exclusion factor, β, vs. the system pressure, P. The SCVMS data are accurate, because the VLE data converge to the same lnβ vs. lnP straight line determined from conventional distillation-still method and a headspace gas chromatography method

  17. The potential of head-space gas chromatography for VLE measurements

    International Nuclear Information System (INIS)

    Highlights: ► HS-GC is a potential technique to obtain VLE data in a high throughput scenario. ► We applied HS-GC and evaluate the main issues to consider. ► Four azeotropic mixtures of industrial interest are studied. ► The thermodynamic analysis of VLE shows the strong non-ideality of the mixtures. - Abstract: Head-space gas chromatography (HS-GC) is thought to allow the performance of (vapour + liquid) equilibrium (VLE) measurements in a fast and automated way. However, two decades after the first applications of HS-GC for this purpose, the potential of this technique is not fully developed yet. Measurements of isothermal VLE and activity coefficients of mixtures can be obtained in a high throughput scenario. However, several considerations have to be taken into account before starting the analysis, such as the equilibration time or the minimum sample volume and the GC response factors. These aspects can strongly influence on the validity of the results and should therefore be determined for each mixture. In this paper, four azeotropic mixtures of interest in the pharmaceutical and chemical industry, i.e., (ethylacetate + water), which forms a heterogeneous azeotrope, (ethylacetate + isooctane), (acetonitrile + toluene) and the ternary mixture (acetonitrile + toluene + tetrahydrofuran), are considered to show the potential of HS-GC for VLE measurements. The thermodynamic analysis of VLE data leads to activity coefficients for the mixtures at (35, 50, and 70) °C. In addition, the experimental data are compared with thermodynamic models and data from the literature, when available.

  18. The buffering-out effect and phase separation in aqueous solutions of EPPS buffer with 1-propanol, 2-propanol, or 2-methyl-2-propanol at T = 298.15 K

    International Nuclear Information System (INIS)

    Highlights: ► Buffering-out is a new liquid–liquid phase separation containing biological buffer. ► EPPS buffer-induced phase separation of aqueous solutions of aliphatic alcohols. ► Phase diagrams of EPPS + water + 1-propanol/2-propanol/2-methyl-2-propanol are studied. ► EPPS breaks the 1-propanol + water and 2-methyl-2-propanol + water azeotropes. ► The (liquid + liquid) equilibria can be well correlated by the NRTL model. - Abstract: Buffering-out is a new liquid–liquid phase separation phenomenon observed in mixtures containing a buffer as a mass separating agent. The (liquid + liquid) equilibrium (LLE) and (solid + liquid + liquid) equilibrium (SLLE) data were measured for the ternary systems {3-[4-(2-hydroxyethyl)piperazin-1-yl]propanesulfonic acid (EPPS) buffer + 1-propanol, 2-propanol, or 2-methyl-2-propanol + water} at T = 298.15 K under atmospheric pressure. The phase boundary data were fitted to an empirical equation relating to the concentrations of organic solvent and buffer. The effective excluded volume (EEV) values of EPPS were obtained from the phase boundary data. The phase-separation abilities of the investigated aliphatic alcohols were discussed. The reliability of the experimental tie-lines was satisfactorily confirmed by the Othmer–Tobias correlation. The experimental tie-lines data for the ternary systems have been correlated using the NRTL activity coefficient model. The separation of these aliphatic alcohols from their azeotropic aqueous mixtures is of particular interest to industrial process. The addition of the EPPS as an auxiliary agent breaks the (1-propanol + water) and (2-methyl-2-propanol + water) azeotropes. The possibility of using the new phase separation systems in the extraction process is demonstrated by using different dyestuffs.

  19. Vapour pressures and vapour-liquid equilibria of propyl acetate and isobutyl acetate with ethanol or 2-propanol at 0.15 MPa. Binary systems

    Directory of Open Access Journals (Sweden)

    Susial Pedro

    2012-01-01

    Full Text Available Vapour pressures of propyl acetate, isobutyl acetate and 2-propanol from 0.004 to 1.6 MPa absolute pressure and VLE data for the binary systems propyl acetate+ethanol, propyl acetate+2-propanol, isobutyl acetate+ethanol and isobutyl acetate+2-propanol at 0.15 MPa have been determined. The experimental VLE data were verified with the test of van Ness and the Fredenslund criterion. The propyl acetate+ethanol or +2-propanol binary systems have an azeotropic point at 0.15 MPa. The different versions of the UNIFAC and ASOG group contribution models were applied.

  20. Modular radwaste volume reduction and solidification systems

    International Nuclear Information System (INIS)

    This paper describes both the modular transportable and the modular mobile liquid radwaste volume reduction and solidification units based on a General Electric Company developed and patented process called AZTECH (a trademark of GE). An AZTECH system removes all water by azeotropic distillation and encapsulates the remaining solids in a polyester compound. The resulting monolith is suitable for either long term above ground storage or shallow land burial. Pilot and demonstration plant testing has confirmed the design parameters. The three processing modules are covered together with data which resulted in Nuclear Regulatory Commission approval on Dec. 30, 1985

  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 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.

  2. 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.

  3. An integrated computer aided system for integrated design of chemical processes

    DEFF Research Database (Denmark)

    Gani, Rafiqul; Hytoft, Glen; Jaksland, Cecilia;

    1997-01-01

    In this paper, an Integrated Computer Aided System (ICAS), which is particularly suitable for solving problems related to integrated design of chemical processes; is presented. ICAS features include a model generator (generation of problem specific models including model simplification and model......, design, control form the basis for the toolboxes. The available features of ICAS are highlighted through a case study involving the separation of binary azeotropic mixtures. (C) 1997 Elsevier Science Ltd....... reduction), a simulator (use of problem specific simulation strategies for steady state and dynamic simulation), toolboxes (thermodynamic toolbox, synthesis toolbox, control toolbox, design toolbox and analysis toolbox), and an interface for problem defintion. Each toolbox solves aspecific set of problems...

  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. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-07-01

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

  7. High temperature reaction of insoluble residue

    International Nuclear Information System (INIS)

    The dissolution and vaporization of insoluble residue in overheated nitric acid, and the oxidation and vaporization of insoluble residue in air were investigated. Only 8% of Ru in the insoluble residue was dissolved into boiling azeotropic nitric acid in 48 hours. The amount of dissolved Ru increases its concentration only by 10% from normal condition. No significant vaporization of Ru was observed. In the air, insoluble residue was not oxidized by 400degC. The metal of Ru started to be oxidized from 550degC, but was not vaporized below 1000degC. (author)

  8. Isobaric (vapour + liquid + liquid) equilibrium data for (di-n-propyl ether + n-propyl alcohol + water) and (diisopropyl ether + isopropyl alcohol + water) systems at 100 kPa

    International Nuclear Information System (INIS)

    Isobaric (vapour + liquid + liquid) equilibria were measured for the (di-n-propyl ether + n-propyl alcohol + water) and (diisopropyl ether + isopropyl alcohol + water) system at 100 kPa. The apparatus used for the determination of (vapour + liquid + liquid) equilibrium data was an all-glass dynamic recirculating still with an ultrasonic homogenizer couple to the boiling flask. The experimental data demonstrated the existence of a heterogeneous ternary azeotrope for both ternary systems. The (vapour + liquid + liquid) equilibria data were found to be thermodynamically consistent for both systems. The experimental data were compared with the estimation using UNIQUAC and NRTL models and the prediction of UNIFAC model

  9. Measurement and correlation of the (vapor + liquid) equilibria of pure 4-ethylmorpholine, 1,2-dimethylisopropylamine and N,N-dimethylethanolamine, and their binary aqueous solutions

    International Nuclear Information System (INIS)

    Highlights: • Vapor pressures of 4-ethylmorpholine, DMIPA and DMAE and their aqueous solutions. • The investigated temperatures are from 273 K through 363 K. • The two first mixtures show positive azeotropic behavior and exhibit positive GE. • The third solution shows either positive or sinusoidal shape for GE. • The Wilson, NRTL and UNIQUAC models were applied. -- Abstract: The vapor pressures of (4-ethylmorpholine + water), (1,2-dimethylisopropylamine + water), (N,N-dimetylethanolamine + water) binary mixtures, and of pure 4-ethylmorpholine, 1,2-dimethylisopropylamine and N,N-dimethylethanolamine components were measured by means of two static devices at temperatures between {273 (or 283) and 333 (or 363)} K. The data were correlated with the Antoine equation. From these data excess Gibbs functions (GE) were calculated for several constant temperatures and fitted to a fourth-order Redlich–Kister equation using the Barker’s method. The (4-ethylmorpholine + water), and (1,2-dimethylisopropylamine + water) binary systems show positive azeotropic behavior. The aqueous solutions of 4-ethylmorpholine and 1,2-dimethylisopropylamine exhibit positive deviations in GE for all investigated temperatures over the whole composition, where the aqueous solution of N,N-dimetyhlethanolamine show a S shape for GE for (273.15 < T < 313.15) K. Additionally, the Wilson, NRTL or UNIQUAC models have been used and quite good results were obtained in the prediction of the total pressure

  10. 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.

  11. 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. 

  12. Isothermal phase (vapour + liquid) equilibrium data for binary mixtures of propene (R1270) with either 1,1,2,3,3,3-hexafluoro-1-propene (R1216) or 2,2,3-trifluoro-3-(trifluoromethyl)oxirane in the temperature range of (279 to 318) K

    International Nuclear Information System (INIS)

    Highlights: • Phase equilibrium data for propene and hexafluoropropylene. • Phase equilibrium data for propene and hexafluoropropylene oxide. • Systems exhibit pressure-maximum azeotropes. • Data well correlated by Peng–Robinson equation of state with the Wong–Sandler mixing rule. - Abstract: Isothermal (vapour + liquid) equilibrium data (P–x–y) are presented for the 1-propene 1,1,2,3,3,3-hexafluoro-1-propene and the 1-propene + 2,2,3-trifluoro-3-(trifluoromethyl)oxirane binary systems. Both binary systems were studied at five temperatures, ranging from (279.36 to 318.09) K, at pressures up to 2 MPa. The experimental (vapour + liquid) equilibrium data were measured using an apparatus based on the “(static + analytic)” method incorporating a single movable Rapid On-Line Sampler-Injector to sample the liquid and vapour phases at equilibrium. The expanded uncertainties are approximated on average as T = 0.07 K, 0.008 MPa, and 0.007 and 0.009 for the temperature, pressure, and the liquid and vapour mole fractions, respectively. A homogenous maximum-pressure azeotrope was observed for both binary systems at all temperatures studied. The experimental data were correlated with the Peng–Robinson equation of state using the Mathias–Copeman alpha function, paired with the Wong–Sandler mixing rule and the Non-Random Two Liquid activity coefficient model. The model provided satisfactory representation of the phase equilibrium data measured

  13. Interlaboratory comparison of methods to determine the stable isotope composition of soil water

    International Nuclear Information System (INIS)

    The results of an interlaboratory comparison of soil distillation techniques are presented. In the comparison, four dry soils (a sand, a gypseous sand and a clayey soil with high and low water contents) were prepared and distributed to 14 laboratories in 4 continents. Water was then extracted from those samples and analysed using the laboratories' standard methods. Various verification procedures were used to ensure that the experiment was truly a comparison of distillation techniques and that the most variation was not due to sample preparation, transport or measurement. The distillation techniques included azeotropic, vacuum, centrifugation and microdistillation methods. Different organic solvents were used in the azeotropic distillations. The vacuum distillations were carried out across a range of temperatures. The results show a large variation (of up to 30 per mille for 2H and 3.4 per mille for 18O) in the isotopic composition of the extracted water. The variation increased as the water content of the soil decreased and was greater for clays than sands at a comparable soil matric suction. The isotope value obtained was correlated with the final extraction temperature. The most probable cause for the variation was incomplete extraction. The study highlights the need to develop standard protocols for each of the major distillation methods. (author). 4 refs, 3 figs, 1 tab

  14. 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.

  15. Recovery of hydrogen iodide

    Science.gov (United States)

    Norman, John H.

    1983-01-01

    A method of extraction of HI from an aqueous solution of HI and I.sub.2. HBr is added to create a two-phase liquid mixture wherein a dry phase consists essentially of HBr, I and HI and is in equilibrium with a wet phase having a far greater HBr:HI ratio. Using a countercurrent extractor, two solutions can be obtained: a dry HBr--HI--I.sub.2 solution and a wet essentially HBr solution. The dry and wet phases are easily separable, and HI is recovered from the dry phase, after first separating I.sub.2, as by distillation. Alternatively, the HI-HBr liquid mixture is treated to catalytically decompose the HI. HBr is recovered from the wet phase by suitable treatment, including high-pressure distillation, to produce an H.sub.2 O--HBr azeotrope that is not more than 25 mole percent HBr. The azeotrope may be returned for use in an earlier step in the overall process which results in the production of the aqueous solution of HI and I.sub.2 without major detriment because of the presence of HBr.

  16. 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.

  17. Measurements of isothermal (vapor + liquid) phase equilibrium for {trifluoroiodomethane (R13I1) + 1,1-difluoroethane (R152a)} from T = (258.150 to 283.150) K

    International Nuclear Information System (INIS)

    Highlights: • VLE data for (R13I1 + R152a) system were measured at four temperatures. • Experiments were based on the vapor-recirculation method. • VLE data were correlated using PR−VdWs and PR−HV−NRTL models. • Azeotropic behavior can be found. - Abstract: In this paper, isothermal (vapor + liquid) equilibrium (VLE) values for {trifluoroiodomethane (R13I1) + 1,1-difluoroethane (R152a)} at T = (258.150 to 283.150) K are presented. The experimental apparatus was based on a vapor-recirculation method. The VLE measurements were regressed by the Peng–Robinson equation of state with two models, the Van der Waals mixing rules and the Huron–Vidal mixing rules using the NRTL activity coefficient model. The newly measured VLE values satisfied the thermodynamic consistency test. The results have led to that the two models selected are both suitable for the description of the binary system. Azeotropic behavior can be found for the system measured

  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. 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.

  1. The radiochemistry of [18 F]-FDG: the first experience in Mexico

    International Nuclear Information System (INIS)

    The present work describes the more used method for the synthesis of 2 - [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) [18 F-] - nucleophilic radio fluorination and i i) a hydrolysis catalyzed by acid. The first reaction incorporates to the [18 F]- fluorine labelled inside the organic precursor 1,3,4,6-tetra- O -acetil-2- O-trifluoromethanesulfonyl- β-D-mannopyranose (triflate of mannose). The mechanism of this reaction is a bimolecular nucleophilic substitution (SN2) with the ion [18 F-] - fluoride; in the second reaction, the hydrolysis of those protective acetyl groups generate the hydroxyl groups free of the [18 F]-FDG. The process includes an azeotropic distillation and several purification steps. (Author)

  2. 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.

  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. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-01

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

  6. Validation of tritium measurements in biological materials

    International Nuclear Information System (INIS)

    The maximum deviation of experimental R value from its real value, which is defined as the ratio of tissue bound to tissue water tritium, has been calculated and verified experimentally by taking consideration of isotopic fractionation arised in the course of water separation. Experimental procedures examined for the purpose are the azeotropic distillation and lyophilization for the removal of tissue water and the oxidative combustion of organic residue either by thermal process or by low temperature plasma generation. Each procedure optimalized by obviating or correcting isotope effects as well as other sources of error has been tested with mixed standards and biological samples. By washing out the exchangeable tritium and also physically bound tritium, the precision and accuracy of R values are further improved

  7. Analysis and optimal process development of the iodine-Sulfur cycle for nuclear hydrogen production

    International Nuclear Information System (INIS)

    Hydrogen is expected to be a main energy vector for the future society. Among many thermo-chemical water splitting technologies for mass production of hydrogen, Iodine-Sulfur (I-S) cycle is considered to be the most promising one. Originated in the 1980s by General Atomics in the United States, the I-S cycle utilizes high temperature heat from energy sources such as nuclear reactors. Despite its high viability relative to many other options, lots of technical challenges need to be resolved until it can practically contribute to the mass production of hydrogen. In the present work, based on the experimental data available from previous works and discussions collected through the literature survey, the optimal operating conditions were proposed for the Bunsen reaction, considering the key concerns of the I-S cycle: i.e., the liquid-liquid (L-L) phase separation performance, the water distributions between the sulfuric acid and poly-hydroiodic acid (HIx) phases, the side reactions, and the operating cost due to the excess iodine and water. All the available experimental data were combined together, and a series of parametric studies were done to find out any trends among parameters. The optimal operating point is determined as 4 mol of excess iodine and 11 mol of excess water in the stoichiometry at temperature of 330K, while the allowable window ranges between 4∼6 mol for excess iodine, 11∼13 moles for excess water, and 330∼350K for temperature. As for the distribution of excess water after the Bunsen reaction and L-L phase separation, 5 mol moves to the sulfuric acid phase and 6∼8 mol to the HIx phase. By controlling the operation within this window, it should be possible to avoid the side reaction and iodine solidification, to increase the HI concentration well above the azeotrope in the HIx section, and to minimize the operating cost caused by the excess iodine and water. With the optimized Bunsen reaction process to yield an over-azeotropic HI liquid

  8. 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.

  9. A thermodynamic study on solubility and liquid-liquid phase behaviour for 2,2,2-trifluoroethanol + cyclohexane + 1-butanol at three temperatures and pressure 101.3 kPa

    International Nuclear Information System (INIS)

    This study demonstrates the course of solubility and (liquid + liquid) equilibrium (LLE) for the system (cyclohexane + 1-butanol + 2,2,2-trifluoroethanol) at temperatures of (288.15, 298.15, and 308.15) K and pressure 101.3 kPa. The titration method was used to assess solubility (binodal) curves, while a direct analytical method to acquire tie lines. The consistency of the binodal curves and phase diagrams data were well calculated by Hand and Othmer-Tobias empirical equations. The NRTL and UNIQUAC thermodynamic models gave accurate tie-line values for the systems. Plait-point, distribution coefficient, solvent selectivity, and NRTL and UNIQUAC binary interaction parameters were obtained. The immiscibility region of the system decreases significantly with increasing temperature. The results present an overview of the high efficiency of liquid extraction using 2,2,2-trifluoroethanol as solvent to yield pure cyclohexane from its 1-butanol azeotrope mixture at ambient temperatures.

  10. Ethanol fermentation from molasses at high temperature by thermotolerant yeast Kluyveromyces sp. IIPE453 and energy assessment for recovery.

    Science.gov (United States)

    Dasgupta, Diptarka; Ghosh, Prasenjit; Ghosh, Debashish; Suman, Sunil Kumar; Khan, Rashmi; Agrawal, Deepti; Adhikari, Dilip K

    2014-10-01

    High temperature ethanol fermentation from sugarcane molasses B using thermophilic Crabtree-positive yeast Kluyveromyces sp. IIPE453 was carried out in batch bioreactor system. Strain was found to have a maximum specific ethanol productivity of 0.688 g/g/h with 92 % theoretical ethanol yield. Aeration and initial sugar concentration were tuning parameters to regulate metabolic pathways of the strain for either cell mass or higher ethanol production during growth with an optimum sugar to cell ratio 33:1 requisite for fermentation. An assessment of ethanol recovery from fermentation broth via simulation study illustrated that distillation-based conventional recovery was significantly better in terms of energy efficiency and overall mass recovery in comparison to coupled solvent extraction-azeotropic distillation technique for the same. PMID:24682264

  11. ARTI Refrigerant Database

    Energy Technology Data Exchange (ETDEWEB)

    Calm, J.M.

    1992-04-30

    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, 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-134a, R-141b, R142b, R-143a, R-152a, R-290 (propane), R-717 (ammonia), ethers, and others as well as azeotropic and zeotropic blends of these fluids. It addresses polyalkylene glycol (PAG), ester, and other lubricants. It also references documents addressing compatibility of refrigerants and lubricants with metals, plastics, elastomers, motor insulation, and other materials used in refrigerant circuits.

  12. 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.

  13. Influence of solvent addition on the physicochemical properties of Brazilian gasoline

    Energy Technology Data Exchange (ETDEWEB)

    E.V. Takeshita; R.V.P. Rezende; S.M.A. Guelli; U. de Souza; A.A. Ulson de Souza [Federal University of Santa Catarina, Florianopolis (Brazil). Chemical Engineering Department

    2008-08-15

    The influence of several solvents (anhydrous ethanol, white spirit, alkylbenzene AB9, diesel) on the physicochemical parameters of gasoline was studied according to ASTM international standard methods. The parameters investigated (distillation curves, density, Reid vapor pressure) showed differentiated behavior, depending on the class of the solvent (oxygenated, light and heavy aliphatic, aromatic) and the quantity added to the gasoline. The azeotropic mixtures formed by ethanol and hydrocarbons showed a strong influence on the behavior of the distillation curves and the location of the point of a sudden change in temperature was shown to be a possible way to detect adulterations and determine the quantity of solvent added to the gasoline. 28 refs., 9 figs., 5 tabs.

  14. Enhancement of impact strength of poly (methyl methacrylate) with surface fine-tuned nano-silica

    Science.gov (United States)

    Wen, Bin; Dong, Yixiao; Wu, Lili; Long, Chao; Zhang, Chaocan

    2015-07-01

    Highly dispersible nanoparticles in organic solvent always receive wide interests due to their compatibility with polymer materials. This paper reported a kind of isopropanol alcohol silica dispersion which obtained using a method of azeotropic distillation. The isopropanol alcohol dispersed silica (IPADS) were treated with coupling agents to fine-tune their surface properties. Polymethyl methacrylate (PMMA) was then used as a research object to test the compatibility between IPADS and polymer. UV-vis spectra indicate that IPADS would reach its high compatibility with PMMA if coupling with trimethoxypropylsilane (PTMS). Followed experiments on PMMA proved that the high compatibility can prominently enhance the impact strength about 30%. The results may provide reference both for nano-silica modification and better understanding of nano-enhanced materials.

  15. 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

  16. 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)

  17. 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.

  18. 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.

  19. 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 .

  20. 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.

  1. 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.

  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. To...... 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...... the performance of predictive thermodynamic models was confirmed in this work by analyzing the calculated values of original UNIFAC model. For solid-liquid equilibrium (SLE) data, new consistency tests have been developed [2]. Some of the developed tests were based in the quality tests proposed for...

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

    Institute of Scientific and Technical Information of China (English)

    刘建本; 阮建明; 邹俭鹏; 李亚军; 骆锋

    2003-01-01

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

  4. A pumped two-phase cooling system for spacecraft

    Science.gov (United States)

    Ollendorf, S.; Costello, F. A.

    1983-01-01

    A pumped, two-phase heat-transport system is being developed for possible use for temperature control of scientific instruments on future NASA missions. As compared to a single-phase system, this two-phase system can maintain tighter temperature control with less pumping power. A laboratory model of the system has been built and tested. The measured heat transfer coefficients were approximately the same as in heat pipes, 220 Btu/hr-sq ft-F, as compared to 25 Btu/hr-sq ft-F for single-phase liquid flow. Heat shearing between experiments has been demonstrated wherein vapor generated in the cold plate of an active experiment was condensed in a cold, unheated experiment. System stability has been observed. However, additional development is needed. The use of non-azeotropic mixtures of coolants appears especially promising as a simple way to determine exit quality and thus control the flow rates to prevent dryout.

  5. 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.

  6. 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.

  7. 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)

  8. 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.

  9. Biofuels sources, biofuel policy, biofuel economy and global biofuel projections

    International Nuclear Information System (INIS)

    The term biofuel is referred to liquid, gas and solid fuels predominantly produced from biomass. Biofuels include energy security reasons, environmental concerns, foreign exchange savings, and socioeconomic issues related to the rural sector. Biofuels include bioethanol, biomethanol, vegetable oils, biodiesel, biogas, bio-synthetic gas (bio-syngas), bio-oil, bio-char, Fischer-Tropsch liquids, and biohydrogen. Most traditional biofuels, such as ethanol from corn, wheat, or sugar beets, and biodiesel from oil seeds, are produced from classic agricultural food crops that require high-quality agricultural land for growth. Bioethanol is a petrol additive/substitute. Biomethanol can be produced from biomass using bio-syngas obtained from steam reforming process of biomass. Biomethanol is considerably easier to recover than the bioethanol from biomass. Ethanol forms an azeotrope with water so it is expensive to purify the ethanol during recovery. Methanol recycles easier because it does not form an azeotrope. Biodiesel is an environmentally friendly alternative liquid fuel that can be used in any diesel engine without modification. There has been renewed interest in the use of vegetable oils for making biodiesel due to its less polluting and renewable nature as against the conventional petroleum diesel fuel. Due to its environmental merits, the share of biofuel in the automotive fuel market will grow fast in the next decade. There are several reasons for biofuels to be considered as relevant technologies by both developing and industrialized countries. Biofuels include energy security reasons, environmental concerns, foreign exchange savings, and socioeconomic issues related to the rural sector. The biofuel economy will grow rapidly during the 21st century. Its economy development is based on agricultural production and most people live in the rural areas. In the most biomass-intensive scenario, modernized biomass energy contributes by 2050 about one half of total energy

  10. Condensation heat transfer coefficients of HCFC22, R410A, R407C and HFC134a at various temperatures on a plain horizontal tube

    International Nuclear Information System (INIS)

    In this study, external condensation heat transfer coefficients (HTCs) of HCFC22, R410A, R407C, and HFC134a were measured on a smooth horizontal tube at 30, 39, and 50 .deg. C with the wall subcooling of 3∼8 .deg. C. The results showed that condensation HTCs decreased for all fluids tested with an increase in temperature. This is due mainly to such properties as the saturated liquid density and liquid thermal conductivity. These properties decrease as the temperature increase and accordingly HTCs decrease. The condensation HTCs of R410A are 9.2∼19.7% higher than those of HCFC22 while those of R134a are 2.5∼10.2% lower than those of HCFC22. Condensation HTCs of R407C, non-azeotropic mixture, are 29.4?34.3% lower than those of HCFC22. Overall, the HTCs of R407C are much lower than those of HCFC22, HFC134a and R410A due to the mass transfer resistance in a diffusion vapor film. Condensation HTCs of HCFC22 and HFC134a are higher than those calculated by Nusselt's equation by 7.7∼11.8% and 4.0∼11.1% respectively. On the other hand, HTCs of R407C measured on plain tube, however, are not well predicted by these well-known prediction correlations due to the introduction of mass transfer resistance associated with non-azeotropic mixtures

  11. 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。

  12. SYNTHESIS OF METHYL METHACRYLATE FROM COAL-DERIVED SYNGAS

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-07-19

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

  13. UNIQUAC activity coefficient model for the systems of 1-propanol + water and 2-propanol + water

    Directory of Open Access Journals (Sweden)

    Numuang, C.

    2005-12-01

    Full Text Available Predictions of vapor liquid equilibria and azeotrope conditions of binary systems of 1-propanol+ water and 2-propanol+water at 30, 60, and 100 kPa were conducted in this work. UNIQUAC activity coefficient and ideal gas models represented behavior of the systems in liquid phase and vapor phase respectively. Experimental data collected from the literature (Gobaldon et al., 1996 and Marzal et al., 1996 were used to calculate energy interaction parameters of the UNIQUAC activity coefficient model by non-linear regression method. The obtained parameters were not dependent on temperature and mole fraction; however, those parameters were dependent on pressure of the system. The mean absolute error of vapor mole fraction of alcohol and water were in the range 3.86-4.65% and 2.33-3.28% respectively for the binary system of 1-propanol +water. The mean absolute error of vapor mole fraction of alcohol and water were in the range 1.93-2.06% and 1.47-1.94% respectively for the binary system of 2-propanol+water. The thermodynamics consistency test proved that the UNIQUAC activity coefficient model was satisfied very well with Gibbs- Duhem equation.

  14. Retrofit of an MTBE-unit to ETBE

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-07-01

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

  15. 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.

  16. Alloy 33: A new material for the handling of HNO3/HF media in reprocessing of nuclear fuel

    International Nuclear Information System (INIS)

    Alloy 33, an austenitic 33Cr-32Fe-31Ni-1.6Mo-0.6Cu-0.4N material shows excellent resistance to corrosion when exposed to highly oxidizing media as e.g. HNO3 and HNO3/HF mixtures which are encountered in reprocessing of nuclear fuel. According to the test results available so far, resistance to corrosion in boiling azeotropic (67%) HNO3 is about 6 and 2 times superior to AISI 304 L and 310 L. In higher concentrated nitric acid it can be considered corrosion resistant up to 95% HNO3 at 25 C, up to 90% HNO3 at 50 C and up to somewhat less than 85% HNO3 at 75 C. In 20% HNO3/7% HF at 50 C its resistance to corrosion is superior to AISI 316 Ti and Alloy 28 by factors of about 200 and 2.4. Other media tested with different results include 12% HNO3 with up to 3.5% HF and 0.4% HF with 32 to 67.5% HNO3 at 90 C. Alloy 33 is easily fabricated into all product forms required for chemical plants (e.g. plate, sheet, strip, wire, tube and flanges). Components such as dished ends and tube to tube sheet weldments have been successfully fabricated facilitating the use of Alloy 33 for reprocessing of nuclear fuel

  17. 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.

  18. 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.

  19. 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.

  20. 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.)

  1. 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.

  2. Room temperature inorganic polycondensation of oxide (Cu2O and ZnO) nanoparticles and thin films preparation by the dip-coating technique

    International Nuclear Information System (INIS)

    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 Cu2O and ZnO. The influence of hydrodynamic parameters over the particle shape and size is discussed. Spherical and rod shape nanoparticles were formed for Cu2O 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

  3. 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.

  4. Single-step method for hydrogen isotope ratio measurement of water in porous media

    Energy Technology Data Exchange (ETDEWEB)

    Turner, J.V.; Gailitis, V.

    1988-06-01

    The standard zinc reduction technique for stable hydrogen isotope analysis has been modified to a single-step method which enables rapid measurement of the deuterium to hydrogen (/sup 2/H//sup 1/H) ratio in water from porous media. The novel feature of the method is microdistillation of water from the porous medium within the zinc reduction tube. The need for such a technique arose from a requirement for /sup 2/H//sup 1/H ratio measurement on microliter quantities of water from unsaturated porous media. Conventional methods using reduction of water over zinc or uranium require free water which must be extracted from the porous medium by either immiscible fluid displacement, vacuum distillation, azeotropic distillation, or squeezing. Each of these methods is time-consuming, can present extraction difficulties at low water content, and may lead to isotope fractionation where phase changes occur during the extraction procedure. Because the technique presented here requires only 100-300 mg, of sample (5-30 mg of water, depending on water content) it has a wide application to experimental studies of water movement in porous media using water either artificially enriched in deuterium or of natural abundance. The authors have used the method successfully in field and laboratory experiments at both environmental and enriched concentrations of deuterium. The method is equally applicable to saturated porous media and also gives a measure of the water content of the sample.

  5. An automated technique for measuring deltaD and delta18O values of porewater by direct CO2 and H2 equilibration.

    Science.gov (United States)

    Koehler, G; Wassenaar, L I; Hendry, M J

    2000-11-15

    The stable-oxygen and -hydrogen isotopic values (deltaD, delta18O) of porewater in geologic media are commonly determined on water obtained by extraction techniques such as centrifugation, mechanical squeezing, vacuum heating and cryogenic microdistillation, and azeotropic distillation. Each of these techniques may cause isotopic fractionation as part the extraction process and each is laborious. Here we demonstrate a new approach to obtain automated, high-precision deltaD and delta18O measurements of porewater in geologic sediments by direct H2- and CO2-porewater equilibration using a modified commercial CO2-water equilibrator. This technique provides an important and cost-effective improvement over current extraction methods, because many samples can be rapidly analyzed with minimal handling, thereby reducing errors and potential for isotopic fractionation. The precision and accuracy of direct H2- and CO2-porewater equilibration is comparable to or better than current porewater extraction methods. Finally, the direct equilibration technique allows investigators to obtain high-resolution (cm scale) porewater deltaD and delta18O profiles using cores from individual boreholes, eliminating the need for costly piezometers or conventional porewater extractions. PMID:11101245

  6. Energy consumption analysis of integrated flowsheets for production of fuel ethanol from lignocellulosic biomass

    International Nuclear Information System (INIS)

    Fuel ethanol is considered one of the most important renewable fuels due to the economic and environmental benefits of its use. Lignocellulosic biomass is the most promising feedstock for producing bioethanol due to its global availability and to the energy gain that can be obtained when non-fermentable materials from biomass are used for cogeneration of heat and power. In this work, several process configurations for fuel ethanol production from lignocellulosic biomass were studied through process simulation using Aspen Plus. Some flowsheets considering the possibilities of reaction-reaction integration were taken into account among the studied process routes. The flowsheet variants were analyzed from the energy point of view utilizing as comparison criterion the energy consumption needed to produce 1 L of anhydrous ethanol. Simultaneous saccharification and cofermentation process with water recycling showed the best results accounting an energy consumption of 41.96 MJ/L EtOH. If pervaporation is used as dehydration method instead of azeotropic distillation, further energy savings can be obtained. In addition, energy balance was estimated using the results from the simulation and literature data. A net energy value of 17.65-18.93 MJ/L EtOH was calculated indicating the energy efficiency of the lignocellulosic ethanol

  7. 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)

  8. 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

  9. 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.

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

    International Nuclear Information System (INIS)

    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 (14C from organically compounds, 36Cl as chloride and free chlorine, 40K 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 (Na2O2 and KMnO4), lyophilization, chemical treatment (Na2O2 and KMnO4) 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

  11. 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

  12. 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.

  13. 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.

  14. 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%.

  15. 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...

  16. 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)

  17. Assessment of solvent extraction efficiency in sandstones using BET [Brunauer-Emmett-Teller] specific surface area measurements

    Energy Technology Data Exchange (ETDEWEB)

    French, P.R.; Mannhardt, K.; DeBree, N.; Shaw, J.C. [Petroleum Recovery Inst. (Canada)

    1995-03-01

    Cleaning core is standard procedure prior to routine measurement of parameters such as porosity and permeability, and before performing special core analyses. It is shown that the cleaning efficiency of different solvents and the degree of cleanliness of a core can be assessed through specific surface area measurements. Berea and Crossfield Cardium sandstone sandstone core plugs containing residual Crossfield Cardium oil from laboratory core floods were extracted with the azeotropic mixture of chloroform/methanol, toluene, and methylene chloride, and the specific surface areas were measured as a function of cleaning time. Solvent cleaning increased the specific surface areas by a factor of three to four in some instances. Cloroform/methanol was found to be the most efficient of the three tested solvents. It is shown that the presence of residual oil may render a drastically reduced specific surface area for a rock, but the specific surface area can be restored to its original value by extraction with chloroform/methanol. The solvent itself does not seem to alter the clay structure within the rock. 19 refs., 4 figs., 5 tabs.

  18. 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.

  19. Syntheses of 7-Substituted α-Cyperone Derivatives for Selective Sigma-1 Receptor over Cannabinoid-1 Receptor Binding Affinities

    International Nuclear Information System (INIS)

    We have successfully synthesized seven α-cyperone derivatives and found that the presence of a hydrogen bond donor/acceptor groups at the C7 position of α-cyperone significantly affects specificity and potency of CB1 receptor binding affinity over sigma-1 receptor binding affinity. In particular, the presence of the amino moiety at the C7 position of α-cyperone is beneficial for binding to sigmia-1 receptor. The molecular mechanism of compound 8 involved in the high binding affinity to sigma-1 receptor is under investigation. We first synthesized α-cyperone 1 by following the previously reported synthetic routes.15-19 In brief, azeotropic imination of (+)-dihydrocarvone and (R)-(+)-1-phenylethylamine followed by alkylation with a slight excess of ethyl vinyl ketone (EVK) in THF at 40 .deg. C produced the Micheal adduct. The resulting adduct was hydrolyzed and then treated with sodium methoxide at room temperature to give an easily separable mixture of α-cyperone 1 and its side product. Flash chromatography resulted in pure α-cyperone 1 in a 30% yield from (+)-dihydrocarvone

  20. 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)

  1. 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.

  2. 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.

  3. Concerted nucleophilic aromatic substitution with 19F‑ and 18F‑

    Science.gov (United States)

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

    2016-06-01

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

  4. 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

  5. Effect of mono-, di- and tri-ethanolammonium tetrafluoroborate protonic ionic liquids on vapour liquid equilibria of ethanol aqueous solution

    International Nuclear Information System (INIS)

    Vapour pressures were measured using a quasi-static ebulliometer for the binary mixture of (water + ethanol) containing one of three protonic ionic liquids (PIL), namely, mono-, di- or tri-ethanolammonium tetrafluoroborate, over the temperature range of (318.24 to 356.58) K at fixed PIL content of 0.30 in mass fraction. The vapour pressure data of the PIL-containing ternary systems were correlated using the NRTL equation with an overall root mean square deviation (RMSD) of 0.0092. The regressed NRTL parameters were used to predict the isobaric vapour liquid equilibria (VLE) for ternary systems (water + ethanol + PIL) at varying mass fraction of PIL and atmospheric pressure (101.3 kPa). It is shown that the effect of PILs on the VLE of the (water + ethanol) mixture follows the order: [HTEA][BF4] > [HDEA][BF4] > [HMEA][BF4]. In addition, the relative volatilities of ethanol to water for pseudo-binary systems (water + ethanol + PIL) were calculated. The results indicate that the PILs studied can enhance the relative volatility of ethanol to water and even break the azeotropic behaviour of ethanol aqueous solution when PIL content is increased to a specified content.

  6. Effect of mono-, di- and tri-ethanolammonium tetrafluoroborate protonic ionic liquids on vapour liquid equilibria of ethanol aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Shen Chong [State Key Laboratory of Chemical Resource Engineering and College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Ma Xiaoyan [College of Science, Beijing University of Chemical Technology, Beijing 100029 (China); Lu Yingzhou [State Key Laboratory of Chemical Resource Engineering and College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Li Chunxi, E-mail: Licx@mail.buct.edu.c [State Key Laboratory of Chemical Resource Engineering and College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029 (China)

    2011-03-15

    Vapour pressures were measured using a quasi-static ebulliometer for the binary mixture of (water + ethanol) containing one of three protonic ionic liquids (PIL), namely, mono-, di- or tri-ethanolammonium tetrafluoroborate, over the temperature range of (318.24 to 356.58) K at fixed PIL content of 0.30 in mass fraction. The vapour pressure data of the PIL-containing ternary systems were correlated using the NRTL equation with an overall root mean square deviation (RMSD) of 0.0092. The regressed NRTL parameters were used to predict the isobaric vapour liquid equilibria (VLE) for ternary systems (water + ethanol + PIL) at varying mass fraction of PIL and atmospheric pressure (101.3 kPa). It is shown that the effect of PILs on the VLE of the (water + ethanol) mixture follows the order: [HTEA][BF{sub 4}] > [HDEA][BF{sub 4}] > [HMEA][BF{sub 4}]. In addition, the relative volatilities of ethanol to water for pseudo-binary systems (water + ethanol + PIL) were calculated. The results indicate that the PILs studied can enhance the relative volatility of ethanol to water and even break the azeotropic behaviour of ethanol aqueous solution when PIL content is increased to a specified content.

  7. 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

  8. 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.

  9. 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.

  10. Monte Carlo simulations of mixtures involving ketones and aldehydes by a direct bubble pressure calculation.

    Science.gov (United States)

    Ferrando, Nicolas; Lachet, Véronique; Boutin, Anne

    2010-07-01

    Ketone and aldehyde molecules are involved in a large variety of industrial applications. Because they are mainly present mixed with other compounds, the prediction of phase equilibrium of mixtures involving these classes of molecules is of first interest particularly to design and optimize separation processes. The main goal of this work is to propose a transferable force field for ketones and aldehydes that allows accurate molecular simulations of not only pure compounds but also complex mixtures. The proposed force field is based on the anisotropic united-atoms AUA4 potential developed for hydrocarbons, and it introduces only one new atom, the carbonyl oxygen. The Lennard-Jones parameters of this oxygen atom have been adjusted on saturated thermodynamic properties of both acetone and acetaldehyde. To simulate mixtures, Monte Carlo simulations are carried out in a specific pseudoensemble which allows a direct calculation of the bubble pressure. For polar mixtures involved in this study, we show that this approach is an interesting alternative to classical calculations in the isothermal-isobaric Gibbs ensemble. The pressure-composition diagrams of polar + polar and polar + nonpolar binary mixtures are well reproduced. Mutual solubilities as well as azeotrope location, if present, are accurately predicted without any empirical binary interaction parameters or readjustment. Such result highlights the transferability of the proposed force field, which is an essential feature toward the simulation of complex oxygenated mixtures of industrial interest. PMID:20540589

  11. 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

  12. 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.

  13. 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

  14. 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.)

  15. Formation and electrical characteristics of silicon dioxide layers by use of nitric acid oxidation method

    International Nuclear Information System (INIS)

    SiO2/Si structure can be formed at low temperatures by use of nitric acid (HNO3) oxidation of Si (NAOS) method. When Si wafers are immersed in ∼ 40 wt% HNO3 solutions at 108 deg C, ∼ 1 nm SiO2 layers are formed. The subsequent immersion in 68 wt% HNO3 (i.e., azeotropic mixture of HNO3 with water) at 121 deg C increases the SiO2 thickness. The 3,5 nm-thick SiO2 layers produced by this two-step NAOS method possess a considerably low leakage current density (e.g. 1 x 102 A/cmi2 at the forward gate bias, VG, of 1.5 V), in spite of the low temperature oxidation, and further decreased (e.g., 8 x 104 A/cm2 at VG = 1.5 V) by post-metallization annealing at 250 deg C in hydrogen atmosphere. In order to increase the SiO2 thickness, a bias voltage is applied during the NAOS method. When 10 V is applied to Si with respect to a Pt counter electrode both immersed in 1 M HNO3 solutions at 25 deg C, SiO2 layers with 8 nm thickness can be formed for 1 h(Authors)

  16. 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.

  17. 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%.

  18. 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.

  19. PETIs as High-Temperature Resin-Transfer-Molding Materials

    Science.gov (United States)

    Connell, John N.; Smith, Joseph G., Jr.; Hergenrother, Paul M.

    2005-01-01

    Compositions of, and processes for fabricating, high-temperature composite materials from phenylethynyl-terminated imide (PETI) oligomers by resin-transfer molding (RTM) and resin infusion have been developed. Composites having a combination of excellent mechanical properties and long-term high-temperature stability have been readily fabricated. These materials are particularly useful for the fabrication of high-temperature structures for jet-engine components, structural components on highspeed aircraft, spacecraft, and missiles. Phenylethynyl-terminated amide acid oligomers that are precursors of PETI oligomers are easily made through the reaction of a mixture of aromatic diamines with aromatic dianhydrides at high stoichiometric offsets and 4-phenylethynylphthalic anhydride (PEPA) as an end-capper in a polar solvent such as N-methylpyrrolidinone (NMP). These oligomers are subsequently cyclodehydrated -- for example, by heating the solution in the presence of toluene to remove the water by azeotropic distillation to form low-molecular-weight imide oligomers. More precisely, what is obtained is a mixture of PETI oligomeric species, spanning a range of molecular weights, that exhibits a stable melt viscosity of less than approximately 60 poise (and generally less than 10 poise) at a temperature below 300 deg C. After curing of the oligomers at a temperature of 371 deg C, the resulting polymer can have a glass-transition temperature (Tg) as high as 375 C, the exact value depending on the compositions.

  20. 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)

  1. 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.

  2. Nitric acid oxidation of Si (NAOS) method for low temperature fabrication of SiO2/Si and SiO2/SiC structures

    International Nuclear Information System (INIS)

    We have developed low temperature formation methods of SiO2/Si and SiO2/SiC structures by use of nitric acid, i.e., nitric acid oxidation of Si (or SiC) (NAOS) methods. By use of the azeotropic NAOS method (i.e., immersion in 68 wt% HNO3 aqueous solutions at 120 deg. C), an ultrathin (i.e., 1.3-1.4 nm) SiO2 layer with a low leakage current density can be formed on Si. The leakage current density can be further decreased by post-metallization anneal (PMA) at 200 deg. C in hydrogen atmosphere, and consequently the leakage current density at the gate bias voltage of 1 V becomes 1/4-1/20 of that of an ultrathin (i.e., 1.5 nm) thermal oxide layer usually formed at temperatures between 800 and 900 deg. C. The low leakage current density is attributable to (i) low interface state density, (ii) low SiO2 gap-state density, and (iii) high band discontinuity energy at the SiO2/Si interface arising from the high atomic density of the NAOS SiO2 layer. For the formation of a relatively thick (i.e., ≥10 nm) SiO2 layer, we have developed the two-step NAOS method in which the initial and subsequent oxidation is performed by immersion in ∼40 wt% HNO3 and azeotropic HNO3 aqueous solutions, respectively. In this case, the SiO2 formation rate does not depend on the Si surface orientation. Using the two-step NAOS method, a uniform thickness SiO2 layer can be formed even on the rough surface of poly-crystalline Si thin films. The atomic density of the two-step NAOS SiO2 layer is slightly higher than that for thermal oxide. When PMA at 250 deg. C in hydrogen is performed on the two-step NAOS SiO2 layer, the current-voltage and capacitance-voltage characteristics become as good as those for thermal oxide formed at 900 deg. C. A relatively thick (i.e., ≥10 nm) SiO2 layer can also be formed on SiC at 120 deg. C by use of the two-step NAOS method. With no treatment before the NAOS method, the leakage current density is very high, but by heat treatment at 400 deg. C in pure hydrogen, the

  3. Nitric acid oxidation of Si (NAOS) method for low temperature fabrication of SiO{sub 2}/Si and SiO{sub 2}/SiC structures

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, H., E-mail: koba771@ybb.ne.jp [Institute of Scientific and Industrial Research, Osaka University, and CREST, Japan Science and Technology Agency, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Imamura, K.; Kim, W.-B.; Im, S.-S.; Asuha [Institute of Scientific and Industrial Research, Osaka University, and CREST, Japan Science and Technology Agency, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan)

    2010-07-15

    We have developed low temperature formation methods of SiO{sub 2}/Si and SiO{sub 2}/SiC structures by use of nitric acid, i.e., nitric acid oxidation of Si (or SiC) (NAOS) methods. By use of the azeotropic NAOS method (i.e., immersion in 68 wt% HNO{sub 3} aqueous solutions at 120 deg. C), an ultrathin (i.e., 1.3-1.4 nm) SiO{sub 2} layer with a low leakage current density can be formed on Si. The leakage current density can be further decreased by post-metallization anneal (PMA) at 200 deg. C in hydrogen atmosphere, and consequently the leakage current density at the gate bias voltage of 1 V becomes 1/4-1/20 of that of an ultrathin (i.e., 1.5 nm) thermal oxide layer usually formed at temperatures between 800 and 900 deg. C. The low leakage current density is attributable to (i) low interface state density, (ii) low SiO{sub 2} gap-state density, and (iii) high band discontinuity energy at the SiO{sub 2}/Si interface arising from the high atomic density of the NAOS SiO{sub 2} layer. For the formation of a relatively thick (i.e., {>=}10 nm) SiO{sub 2} layer, we have developed the two-step NAOS method in which the initial and subsequent oxidation is performed by immersion in {approx}40 wt% HNO{sub 3} and azeotropic HNO{sub 3} aqueous solutions, respectively. In this case, the SiO{sub 2} formation rate does not depend on the Si surface orientation. Using the two-step NAOS method, a uniform thickness SiO{sub 2} layer can be formed even on the rough surface of poly-crystalline Si thin films. The atomic density of the two-step NAOS SiO{sub 2} layer is slightly higher than that for thermal oxide. When PMA at 250 deg. C in hydrogen is performed on the two-step NAOS SiO{sub 2} layer, the current-voltage and capacitance-voltage characteristics become as good as those for thermal oxide formed at 900 deg. C. A relatively thick (i.e., {>=}10 nm) SiO{sub 2} layer can also be formed on SiC at 120 deg. C by use of the two-step NAOS method. With no treatment before the NAOS method

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

    Directory of Open Access Journals (Sweden)

    Meyrambek Ospanov

    2014-10-01

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

  5. Phase behavior of ternary mixtures {aliphatic hydrocarbon + aromatic hydrocarbon + ionic liquid}: Experimental LLE data and their modeling by COSMO-RS

    International Nuclear Information System (INIS)

    Highlights: • Several ionic liquids were studied as solvent to separate aromatic and aliphatic hydrocarbons. • (Liquid + liquid) equilibrium data were experimental determined at T = 298.15 K and p = 1 atm. • Selectivity and solute distribution ratio were calculated. • Experimental data were correlated using NRTL and UNIQUAC thermodynamic models. • COSMO-RS model was applied to predict the (liquid + liquid) equilibrium. - Abstract: Separation of aromatic and aliphatic hydrocarbons is a complex process in the petrochemical industry due to overlapping boiling points and azeotrope formation. In this paper, liquid extraction of aromatic compounds (toluene and ethylbenzene) from aliphatic compounds (hexane and cyclohexene) using ionic liquids (1-butyl-3-methylimidazolium methylsulfate, BMimMSO4, 1-propyl-3-methylimidazolium bis{trifluoromethylsulfonyl}imide, PMimNTf2, and 1-butyl-3-methylimidazolium bis{trifluoromethylsulfonyl}imide, BMimNTf2) as solvent was studied. (Liquid + liquid) equilibrium (ELL) data for the ternary systems {hexane (1) + ethylbenzene (2) + BMimMSO4, or BMimNTf2, or PMimNTf2 (3)}, {hexane (1) + toluene (2) + BMimMSO4 (3)} and {cyclohexene (1) + ethylbenzene (2) + BMimMSO4 (3)} were experimentally determined at T = 298.15 K and atmospheric pressure. Moreover, an analysis of the influence of the structure of each compound on the phase behavior was also carried out. The ability of the studied ILs to separate aromatic from aliphatic compounds was evaluated in terms of the solute distribution ratio, β, and the selectivity, S. The Non Random Two-Liquid (NRTL) and UNIversal QUAsiChemical (UNIQUAC) thermodynamic models were used to correlate the experimental LLE data. Furthermore, the COnductor-like Screening MOdel for Real Solvents (COSMO-RS) was applied to predict the (liquid + liquid) equilibrium. The suitability of this model to describe the phase behavior of the studied mixtures was evaluated comparing the experimental and calculated data

  6. Measurement of mass transfer coefficient in direct contact sulfuric acid concentration for IS process

    International Nuclear Information System (INIS)

    Hydrogen is expected to serve as a clean secondary energy, because it can be manufactured from water, used in a variety of energy end-use sectors as fuel, and returned to water after burning. For the realization of hydrogen energy system, development of efficient and economical hydrogen production methods is required to meet the future huge demand of hydrogen. The Iodine-Sulfur (IS) process is a promising candidate of such hydrogen production methods, in which water reacts with iodine and sulfur dioxide to produce hydrogen iodide and sulfuric acid (Bunsen reaction) and the produced acids are then decomposed to produce hydrogen and oxygen, respectively. This study is concerned with the development of IS process equipment named direct contact sulfuric acid concentrator, in which gaseous mixture produced by thermal decomposition of sulfuric acid contacts directly with sulfuric acid solution. In the concentrator, the high temperature heat of the decomposed gas is recovered and used to concentrate sulfuric acid solution and, at the same time, the undecomposed sulfuric acid is condensed and separated from the decomposition products of sulfur dioxide and oxygen. Although the concept is very attractive from the viewpoint of the development of compact and efficient sulfuric acid concentrator, little is known on the heat and mass transfer relevant to the concentrator. Therefore, experimental methods were discussed to acquire the gas-phase mass transfer coefficient required for the optimal design of the concentrator. Assuming the use of wetted-wall column and also of the sulfuric acid of azeotropic composition as the test solution which could eliminate the liquid-phase mass transfer resistance, the column specification and the measurement conditions were determined by which flooding could be avoided and surface wetting could be assured, as well. (author)

  7. 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

  8. Ebulliometric determination and prediction of (vapor + liquid) equilibria for binary and ternary mixtures containing alcohols (C1-C4) and dimethyl carbonate

    International Nuclear Information System (INIS)

    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 {methanol + propan-1-ol + dimethyl carbonate (DMC)}, and four binary mixtures, namely an {alcohol (C3 or C4) + DMC}, 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.

  9. 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.

  10. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1983-08-01

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

  12. [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

  13. Tritium monitoring in environment at ICIT Tritium Separation Facility

    International Nuclear Information System (INIS)

    Full text: The Cryogenic Pilot is an experimental project developed within the national nuclear energy research program, which is designed to develop the required technologies for tritium and deuterium separation by cryogenic distillation of heavy water. The process used in this installation is based on a combination between liquid-phase catalytic exchange (LPCE) and cryogenic distillation. Basically, there are two ways that the Cryogenic Pilot could interact with the environment: by direct atmospheric release and through the sewage system. This experimental installation is located 15 km near the region biggest city and in the vicinity - about 1 km, of Olt River. It must be specified that in the investigated area there is an increased chemical activity; almost the entire Experimental Cryogenic Pilot's neighborhood is full of active chemical installations. This aspect is really essential for our study because the sewerage system is connected with the other three chemical plants from the neighborhood. For that reason we progressively established elements of an environmental monitoring program well in advance of tritium operation in order to determine baseline levels. The first step was the tritium level monitoring in environmental water and wastewater of industrial activity from neighborhood. In order to establish the base level of tritium concentration in the environment around the nuclear facilities, we investigated the sample preparation treatment for different types of samples: onion, green beams, grass, apple, garden lettuce, tomato, cabbage, strawberry and grapes. We used azeotropic distillation of all types of samples, the carrier solvent being toluene from different Romanian providers. All measurements for the determination of environmental tritium concentration were performed using liquid scintillation counting (LSC), with the Quantulus 1220 spectrometer. (authors)

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

    Science.gov (United States)

    Hatano, Manabu; Ishihara, Kazuaki

    2013-03-11

    A facile, atom-economical, and chemoselective esterification is crucial in modern organic synthesis, particularly in the areas of pharmaceutical, polymer, and material science. However, a truly practical catalytic transesterification of carboxylic esters with various alcohols has not yet been well established, since, with many conventional catalysts, the substrates are limited to 1°- and cyclic 2°-alcohols. In sharp contrast, if we take advantage of the high catalytic activities of La(Oi-Pr)(3), La(OTf)(3), and La(NO(3))(3) as ligand-free catalysts, ligand-assisted or additive-enhanced lanthanum(III) catalysts can be highly effective acid-base combined catalysts in transesterification. A highly active dinuclear La(III) catalyst, which is prepared in situ from lanthanum(III) isopropoxide and 2-(2-methoxyethoxy)ethanol, is effective for the practical transesterification of methyl carboxylates, ethyl acetate, weakly reactive dimethyl carbonate, and much less-reactive methyl carbamates with 1°-, 2°-, and 3°-alcohols. As the second generation, nearly neutral "lanthanum(III) nitrate alkoxide", namely La(OR)(m)(NO(3))(3-m), has been developed. This catalyst is prepared in situ from inexpensive, stable, low-toxic lanthanum(III) nitrate hydrate and methyltrioctylphosphonium methyl carbonate, and is highly useful in the non-epimerized transesterification of α-substituted chiral carboxylic esters, even under azeotropic reflux conditions. In these practical La(III)-catalyzed transesterifications, colorless esters can be obtained in small- to large-scale synthesis without the need for inconvenient work-up or careful purification procedures. PMID:23325290

  15. 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%.

  16. 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

  17. Comparación de Secuencias de Deshidratación de Etanol por Destilación Extractiva con Benceno Comparison of Ethanol Dehydration Sequences by Extractive Distillation with Benzene

    Directory of Open Access Journals (Sweden)

    V. M. Beckley

    2005-01-01

    Full Text Available Este trabajo tiene el objetivo de comparar un conjunto de secuencias de separación para la deshidratación de una mezcla diluida de etanol en agua por destilación azeotrópica heterogénea usando benceno como solvente. Previo a la comparación, las secuencias se optimizan cambiando sus parámetros de diseño. Las tareas de optimización y comparación se llevaron a cabo con los programas HYSYS y DISTIL. Se compararon secuencias constituidas por dos y tres columnas. Algunas secuencias fueron extraídas de patentes y otras fueron generadas con un proceso de síntesis. Los resultados obtenidos para la comparación se resumen en un balance entre el número de platos y un factor que tiene en cuenta el caudal total de vapor de la secuencia.The objective of this work was to compare separation sequences for the dehydration of a diluted mixture of ethanol in water by azeotropic heterogeneous extractive distillation using benzene as a solvent. Prior to the comparison, the sequences are optimized by changing their design parameters. The tasks of optimization and comparison are performed using the HYSYS and DISTIL programs. Sequences were made up of two and three columns were compared. Some sequences were obtained from patents, and others were generated by a synthesis process. Results obtained for the comparison can be summarised as a balance between plate number and a factor that accounts for the total vapor flow of the sequence.

  18. 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%.

  19. 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。

  20. 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.

  1. Thermodynamic Phase Relations in the MgO-FeO-SiO2 System in the Lower Mantle

    Science.gov (United States)

    Wolf, A. S.; Caracas, R.; Asimow, P. D.

    2008-12-01

    The perovskite (Pv) to post-perovskite (PPv) phase transition at pressures near the Earth's core-mantle boundary (CMB) is currently the favored candidate for explaining most, if not all, of the peculiarities of the D" layer (~200 km region above core) [1, 2]. Additionally, the pressure- and temperature-dependence of this phase boundary in the Earth provides the possibility of an important new thermo-barometer at the bottom of the convecting mantle. The post-perovskite phase boundary in pure MgSiO3 is fairly well known, but the experimental and calculated results on the partitioning of Fe among the stable coexisting phases and its influence on the transition pressure are currently contradictory [3, 4, 5, 6]. Using density functional theory (DFT), we investigate the MgO-FeO-SiO2 ternary system over the temperatures and pressures relevant to the core-mantle boundary. We use DFT to calculate the energies of the relevant stable phases (Pv, PPv, (Mg,Fe)O magnesio-wustite, and SiO2 stishovite) for a range of Fe compositions along the Mg-Fe binary. These results are fit with a Vinet equation of state, allowing us to parameterize the effect of both pressure and Fe composition. The effect of temperature is modeled using a Grüneisen thermal correction, where the vibrational heat capacities are determined using DFT perturbation calculations and the quasi-harmonic approximation. These pressure-, temperature-, and composition-dependent equations of state are then used to explore the predicted phase relations. The results of this investigation are a complete thermodynamic description of the stable phases for this simplified chemistry and a theoretical prediction for iron partioning in the lower mantle. In particular, we find that there may be a coincidence point (azeotrope) on the Pv-PPv phase loop, across which the sense of Fe-partitioning changes sign, as well as significant immiscibility between Mg-rich and Fe-rich post-perovskite. These findings help explain many of the

  2. 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。

  3. 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

  4. 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.

  5. 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

  6. 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

  7. Evaluation of specific tritium transfer parameters in equilibrium conditions for Cernavoda area

    International Nuclear Information System (INIS)

    In Romania, a CANDU nuclear power plant with five reactors of 600 MWe is under construction. The first unit reached its criticality on April 1996 and became operational at full power on December 1996. The nuclear power plant is placed in Cernavoda area, in the S-E of Romania, between the Danube River and the Danube-Black Sea Canal. The prevalent local climate is continental and agricultural activity in the neighbourhood of the nuclear power plant is of intensive type. The routine atmospheric tritium release from the 3 GWe nuclear power plant is expected to be about 460 TBq/year and the aqueous release is expected to be 350 TBq/year. The aim of this study was to evaluate the environmental tritium reference level before commissioning the nuclear power plant. Representative samples for Cernavoda area were analysed: air humidity; water from Danube River, Danube-Black Sea Canal, lakes; drinking and ground water, rain (snow) water; soil at different depths; tissue free water tritium in vegetal and animal foodstuff relevant for human diet: cereals (wheat, maize, barley), vegetables (potato, tomato, cabbage, onion, bean), fruits, grapes, wine and milk; organically bound tritium in wheat and maize grains. The equipment and methods used were: Liquid scintillation analyzer of type TRICARB 1900 TR; scintillation cocktails of Instagel and Pico Fluor LLT type; sampling system for trapping the atmospheric tritium on molecular sieves; furnace; vacuum line and freeze trap (-60 deg. C); equipment for simple, fractionating and azeotropic distillation. The background level of tritium concentration was determined in environmental samples in Cernavoda area, in preoperational stage of nuclear power plant. The mean values determined during 1994-early 1996 are : (7.4±5.5) Bq/L in air humidity, (3.1±1.0) Bq/L in water, (3.53±0.4) Bq/L in tissue water from vegetable and (4.9±1.7) Bq/L in tissue water from cereals (grains). The values of tritium concentration in air, water, soil and

  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. 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].

  10. Origins of Linear Partitioning in Binary Solutions: the Exchange Coefficient

    Science.gov (United States)

    Morse, S. A.

    2006-05-01

    Linear partitioning occurs when, as often in petrologic systems and perhaps always in azeotropes, a straight- line relationship occurs when the partition coefficient D = X1S/X1L is plotted against the solid composition X2S and runs from an intercept value KD at pure (2) to 1.0 at pure (1). The equation is then D = KD*X2S + X1S (Morse 1997, JGeol 105:471; 2000 GCA, 64:2309). The notation KD was taken from its long-standing familiarity in binary solutions (Roeder & Emslie 1970, CMP 29:275) and described as the exchange coefficient (Beattie et al. 1993 GCA 57:1605). But the binary loop is not in itself an exchange equilibrium; it is a transfer equilibrium marching to a different drummer, and that causes a problem (Kretz 2005, CanMin 43:1349). In at least three ways, the binary loop qualifies as an exchange reaction and justifies calling the intercept KD. To the experimentalist this issue never arises. In a perfect liquidus experiment, an infinitesimal mass of liquid is indeed transferred to the crystal. A second bulk composition is then made, and at the new liquidus a second mass transfer occurs. The ensemble of all such perfect partitioning experiments in sufficient number then completely delineates the binary loop without any continuous transfer at changing T having taken place. The partitionings are therefore truly independent of the path. Moreover, each equilibrium pair defines a common tangent in G-X space whose intercept at pure (2) unarguably gives the value of the common chemical potential, a partial Gibbs energy. But where is the exchange reaction? The real experimentalist makes no perfect experiments, and neither does nature. In reality, the barrier to nucleation (particularly formidable in the case of plagioclase) dictates that the crystals nucleate only at some supercooling. They therefore have some composition between the initial solidus and the liquid lying at the bulk composition (BC). Over time the two phases may drift apart by diffusion, the crystal

  11. 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

  12. 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.

  13. 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

  14. 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.

  15. 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

  16. 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