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1

Efficiencies of trays in cryogenic distillation columns  

NASA Astrophysics Data System (ADS)

This Paper considers the behaviour of the distillation trays in conventional use in cryogenic air separation plants. An earlier study showed that the trays should operate at higher efficiencies than plant experience would indicate. This conclusion was based on the assumption of uniform liquid flow across the trays. In practice, stagnant zones can occur which reduce the efficiency. A study of a small hole-size tray, rectangular in shape, providing uniform flow has confirmed the predictions of the theoretical model by producing high efficiencies. These results, together with those from the earlier study, provide an indication of the benefits of improving the flow behaviour of air separation distillation trays.

Biddulph, M. W.

1986-01-01

2

Nonlinear Model Predictive Control of High Purity Distillation Columns for Cryogenic Air Separation  

Microsoft Academic Search

High purity distillation columns are critical unit operations in cryogenic air separation plants that supply purified gases to a number of industries. We have developed a nonlinear model predictive control (NMPC) strategy based on the assumption of full-state feedback for a prototypical cryogenic distillation column to allow effective operation over a wide range of plant production rates. The controller design

Zhongzhou Chen; Michael A. Henson; Paul Belanger; Lawrence Megan

2010-01-01

3

Effects of helium on separation characteristics of cryogenic distillation column cascade for fusion reactor  

Microsoft Academic Search

By choosing the cryogenic distillation column cascade developed at Los Alamos National Laboratory, the effects of helium on separation characteristics of the columns are analyzed in a probable case of input and output specifications. Column (2) is mainly affected by the presence of helium. If the helium percentage in the raw fuel input is 1%, the column performance can be

Kinoshita

1984-01-01

4

Low-order dynamic modeling of cryogenic distillation columns based on nonlinear wave phenomenon  

Microsoft Academic Search

A low-order dynamic model based on nonlinear wave theory is developed for a cryogenic distillation column used for nitrogen purification. By tracking the wave front propagating through the column, a simple mathematical model capable of describing the essential column dynamics is derived. The combined reboiler\\/condenser system is modeled using rigorous mass and energy balances. The low-order model is compared with

Guang-Yan Zhu; Michel A. Henson; Lawrence Megan

2001-01-01

5

Separation characteristics of cryogenic distillation column with a feedback stream for separation of protium and tritium  

SciTech Connect

A mathematical simulation procedure is developed for a single cryogenic distillation column with a feedback stream and a catalytic equilibrator used for protium-tritium (HT) separation. Large errors in calculation of mole fractions of the HT in the two products may occur unless special care is taken. Errors are minimized here by solving a single-variable nonlinear equation using the Newton-Raphson method. Parametric investigations of interest for column design and operation are also presented. One result is that the sidestream location is found to strongly affect column performance, and the optimum location depends strongly on the external feed composition. Further, as the mole percentage of HT in the external feed increases, the flow rate of the sidestream must be increased. Finally the effect of thermodynamic properties of the isotopes and of the decay heat of tritium on static column behavior are examined. Differences in the latent heat of vaporization among the three molecular species (H/sub 2/, HT, and T/sub 2/) are found to be significant. It appears that consideration of the decay heat of tritium and of the nonideality of the H/sub 2/-HT-T/sub 2/ solution is necessary to accurately predict the tritium concentration in the top product of high purity protium, a key output parameter. The usual assumption of equal molal heats and equal molal overflows within the column can lead to error in the reboiler load exceeding +250%.

Masahiro Kinoshita; Yuji Naruse

1982-07-01

6

Experimental results of hydrogen distillation at the low power cryogenic column for the production of deuterium depleted hydrogen  

SciTech Connect

The Deuterium Removal Unit (DRU) has been designed and built at the Petersburg Nuclear Physics Inst. (PNPI) to produce isotopically pure hydrogen with deuterium content less than 1 ppm. The cryogenic distillation column of 2.2 cm inner diameter and 155 cm packing height is the main element of the DRU. Column performances at different hydrogen distillation operating modes have been measured. The height equivalent to theoretical plate (HETP) for the column is 2.2 cm and almost constant over a wide range of vapour flow rates. Deuterium depleted hydrogen with a deuterium content of less than 0.1 ppm was produced in required quantity. (authors)

Alekseev, I.; Fedorchenko, O.; Kravtsov, P.; Vasilyev, A.; Vznuzdaev, M. [Petersburg Nuclear Physics Inst., Leningrad district, Gatchina, 188300 (Russian Federation)

2008-07-15

7

Derivation of Working Equations for Dynamic Simulation of Cryogenic Distillation Column Incorporating Vapor Holdups on Stages within Column.  

National Technical Information Service (NTIS)

If a distillation column has a packed section whose inner diameter is considerably small, a small number of the total theoretical stages, and a condenser whose volume is very large, the vapor holdup in the condenser could be significant in dynamic simulat...

M. Kinoshita

1983-01-01

8

A simplified mathematical model of the cryogenic distillation with application to the (13C) isotope separation column  

NASA Astrophysics Data System (ADS)

The isotope (13C) has a widespread application in many fields such as chemistry, physics, medicine, etc. To obtain a high concentration in isotope of interest, in our case (13C), it is used the method of cryogenic distillation of carbon monoxide (CO) which is based on the difference between the vapor pressure of (12C16O) and (13C16O) at the temperature of liquid nitrogen. Isotopic separation plant, used to obtain the isotope (13C), is a complex installation, with many inputs and outputs, rather difficult to control. Due to this reason, from the point of view of automation, it is needed a simplified mathematical model. This model can be determined only with some presumption and simplification assumptions. Using the physical laws, the hydrodynamic part of the process and the mass balance will be described by partial differential equations. In order to design a controller for the column, it is needed a transfer function or a statespace realization of the plant, which is the main contribution of the present work. Implementing this mathematical model will be the key element for describing and understanding the operation of the plant and for future development of process control strategies.

Neaga, A. O.; Festila, C.; Dulf, E. H.; Both, R.; Szelitzky, T.; Gligan, M.

2012-02-01

9

Simplified distillation column controls  

SciTech Connect

A simple, energy efficient method of controlling single or double distillation columns for the production of ethyl alcohol is described. The control system is based on a material balance scheme centered around a thermostat actuated control valve to regulate reflux rate and product purity. Column bottom's levels are automatically regulated by vented suction lines on the pump inlets. Methods of minimizing control input variations are used including column insulation, stillage-to-beer heat exchanger, and a steam pressure regulator.

Badger, P.; Pile, R.; Lightsey, G.

1984-01-01

10

Cryogenic hydrogen isotope distillation for the fusion fuel cycle  

SciTech Connect

Cryogenic distillation is an attractive method for the hydrogen isotopic separations required in fusion fuel cycles. The theoretical and practical aspects of designing and constructing such systems are well established. Practical considerations in the design of systems are presented and applied to the Isotope Separation System (ISS) at the Tritium Systems Test Assembly (TSTA), as well as systems of distillation columns that might be used for a reactor such as the Tokamak Fusion Core Experiment (TFCX) and the recovery of breeding blanket product.

Sherman, R.H.

1985-01-01

11

Optimal design of thermally coupled distillation columns  

Microsoft Academic Search

This paper considers the optimal design of thermally coupled distillation columns and dividing wall columns using detailed column models and mathematical optimization. The column model used is capable of describing both conventional and thermally coupled columns, which allows comparisons of different structural alternatives to be made. Possible savings in both operating and capital costs of up to 30% are illustrated

G. Duennebier; Constantinos C. Pantelides

1999-01-01

12

Investigation related to hydrogen isotopes separation by cryogenic distillation  

SciTech Connect

Research conducted in the last fifty years has shown that one of the most efficient techniques of removing tritium from the heavy water used as moderator and coolant in CANDU reactors (as that operated at Cernavoda (Romania)) is hydrogen cryogenic distillation. Designing and implementing the concept of cryogenic distillation columns require experiments to be conducted as well as computer simulations. Particularly, computer simulations are of great importance when designing and evaluating the performances of a column or a series of columns. Experimental data collected from laboratory work will be used as input for computer simulations run at larger scale (for The Pilot Plant for Tritium and Deuterium Separation) in order to increase the confidence in the simulated results. Studies carried out were focused on the following: - Quantitative analyses of important parameters such as the number of theoretical plates, inlet area, reflux flow, flow-rates extraction, working pressure, etc. - Columns connected in series in such a way to fulfil the separation requirements. Experiments were carried out on a laboratory-scale installation to investigate the performance of contact elements with continuous packing. The packing was manufactured in our institute. (authors)

Bornea, A.; Zamfirache, M.; Stefanescu, I.; Preda, A.; Balteanu, O.; Stefan, I. [INC-DTCI-ICSI Rm. Valcea, str.Uzinei, Nr.4, 240050 (Romania)

2008-07-15

13

Numerically optimized performance of diabatic distillation columns  

Microsoft Academic Search

Recently, the concept of equal thermodynamic distance (ETD) has been proposed to minimize entropy production in a distillation process using a diabatic column. ETD gives the optimal temperature profile to first-order in N?1, where N is the number of trays. ETD, however, does not generally give the true minimum for distillation columns with few trays. We therefore apply a fully

Markus Schaller; Karl Heinz Hoffmann; Gino Siragusa; Peter Salamon; Bjarne Andresen

2001-01-01

14

Avoid problems during distillation column startups  

Microsoft Academic Search

The startup of a distillation column is the end product of the design process. Indeed, startup is the culmination of the theory and practice of designing the column to meet the process objectives. The author will direct most of this discussion towards column revamps due to their inherent complexity; however, the points apply equally to new columns, as well. The

Sloley

1996-01-01

15

Simplified Design of Batch Reactive Distillation Columns  

Microsoft Academic Search

This work proposes a simplified methodology for the analysis and design of reactive batch distillation columns based on the McCabe-Thiele method for reactive continuous columns and on the concept of a reactive difference point. To extend the application of the concept of a reactive difference point for reactive batch distillation columns, expressions for the McCabe-Thiele operating line and for the

Maria E. Huerta-Garrido; Vicente Rico-Ramirez; Salvador Hernandez-Castro

2004-01-01

16

Study on a Continuous Heat Integrated Distillation Column  

Microsoft Academic Search

A novel continuous heat integrated distillation column called a concentric column has been studied using computer simulation. It is shown that a concentric column is a novel implementation of a thermodynamically reversible distillation column and has a lower energy loss than an ordinary distillation column. Our studies show that a concentric column has reduced column height, since the stripping section

Thomas Glenchur; Rakesh Govind

1987-01-01

17

Optimal design of complex azeotropic distillation columns  

Microsoft Academic Search

Geometric methods are valuable tools for process synthesis and design since they provide designers with intuition and quantitative results. The calculation and graphical representation of azeotropes, residue curves and distillation boundaries provide a wealth of knowledge about the entire composition space. This paper shows how these tools can be used for optimal design of complex azeotropic distillation columns. Two examples

Stanislaw K Wasylkiewicz; Leo C Kobylka; Francisco J. L Castillo

2000-01-01

18

Simulation and control of reactive distillation column  

Microsoft Academic Search

The paper discusses about the application of PID controller and fuzzy controller in reactive distillation column. A generic mathematical model of reactive distillation has been taken for simulation. The PID and fuzzy controllers are designed for the process and then the overall process is controlled by using conventional (PID) and intelligent (fuzzy) controllers separately. Conventional PID controller is used to

Ujjwal Kapoor; Asha Rani; Vijander Singh; J. R. P Gupta

2011-01-01

19

Thermal Integration of a Distillation Column Through Side-Exchangers  

Microsoft Academic Search

Thermal integration of a distillation column with the background process through side exchangers (side reboilers\\/condensers) is important for designing an energy-efficient distillation column. Thermal integration of a distillation column through side exchangers also improves the exergetic efficiency of the column. Invariant rectifying and stripping (IRS) curves are employed for thermodynamic analysis of a distillation column. Different configurations for side-exchanger integration

S. Bandyopadhyay

2007-01-01

20

Heat Integration in Batch Distillation Column  

NASA Astrophysics Data System (ADS)

A new heat integrated batch distillation column has been configured in this paper. Here the column and reboiler are connected in an annular arrangement and a compressor is positioned between them to maintain the pressure difference. The heat integration is between the rectifying batch column and one concentric reboiler. Ethanol-Water binary system is chosen as an example for the design and analysis of this heat integrated batch distillation column (HIBDiC). In this work, a sensitivity test for selecting the optimal value of the total number of trays and reboiler duty and a thermodynamic feasibility test for its design acceptability has been accomplished. The principal objective of this study is to investigate the influence of compression ratio (CR) on the energy consumption of distillation and to find out the optimal value of CR. Also a comparative analysis of HIBiDC on energy consumption in steady state as well as in dynamic state has been carried out on the basis of its conventional model. The proposed scheme is capable to save the energy up to 50.52% compared to its conventional one by selecting the CR of 1.4 as an optimal value.

Maiti, Debadrita; Jana, Amiya K.; Samanta, Amar Nath

2010-10-01

21

Control of a heat pump assisted distillation column  

Microsoft Academic Search

Based on the basic concepts and techniques involved for automatic control of continuous distillation columns for binary systems, a scheme is proposed for the control of distillation column for the ethanol–water system. Using the established norms for the control of mechanical vapor compression heat pumps, a control scheme is proposed for the heat pump assisted distillation column for the ethanol–water

Ishwar Chandra; Sukumar Devotta

1998-01-01

22

Final Report, Distillation Column Flooding Predictor  

SciTech Connect

The Flooding Predictor is an advanced process control strategy comprising a patented pattern-recognition methodology that identifies pre-flood patterns discovered to precede flooding events in distillation columns. The grantee holds a U.S. patent on the modeling system. The technology was validated at the Separations Research Program, The University of Texas at Austin under a grant from the U. S. Department of Energy, Inventions & Innovation Program. Distillation tower flooding occurs at abnormally high vapor and/or liquid rates. The loss in tray efficiencies is attributed to unusual behavior of liquid inventories inside the column leading to conditions of flooding of the space in between trays with liquid. Depending on the severity of the flood condition, consequences range from off spec products to equipment damage and tower shutdown. This non-intrusive pattern recognition methodology, processes signal data obtained from existing column instrumentation. Once the pattern is identified empirically, it is modeled and coded into the plant's distributed control system. The control system is programmed to briefly "unload" the tower each time the pattern appears. The unloading takes the form of a momentary reduction in column severity, e.g., decrease bottom temperature, reflux or tower throughput. Unloading the tower briefly at the pre-flood state causes long-term column operation to become significantly more stable - allowing an increase in throughput and/or product purity. The technology provides a wide range of value between optimization and flooding. When a distillation column is not running at capacity, it should be run in such a way ("pushed") that optimal product purity is achieved. Additional benefits include low implementation and maintenance costs, and a high level of console operator acceptance. The previous commercial applications experienced 98% uptime over a four-year period. Further, the technology is unique in its ability to distinguish between different flooding mechanisms within the same tower, e.g., liquid and jet flooding.

George E. Dzyacky

2003-05-31

23

Improve distillation-column control design  

SciTech Connect

Steady-state process models have long been used to assist the engineer in designing control strategies for distillation columns. Yet, a large number of industrial columns still operate in manual or with ineffectual controls. So, better control design techniques using steady-state models certainly are needed. In this article, the authors introduced an improved method that already has proven itself on 33 industrial columns. This article deals exclusively with the design of single-point composition controls. The vast majority of columns have one-sided composition specifications. With such specifications, a single-point composition control scheme can keep both top and bottom product compositions at or below limits for a wide range of disturbances. The predominance of one-sided specifications means that the main incentive for dual-point control schemes is achieving energy savings. In most cases, though, the energy savings are small and do not justify the added difficulty of implementing and maintaining dual-point control. Additionally, dual-point schemes often have significantly longer recoveries from upsets due to interactions between the control loops. The design procedure can be best thought of as a general approach rather than a single detailed procedure that covers all cases. The produce must be adapted to each problem because there are many different types of distillation and almost every industrial problem has some unique requirement.

Fruehauf, P.S.; Mahoney, D.P.

1994-03-01

24

Studies on dynamics and control of distillation columns.  

National Technical Information Service (NTIS)

Distillation is an important unit operation in which a given feed is separated into two or more products of different compositions. The separation requires input of relatively large amounts of energy. Improved composition control of distillation columns m...

E. W. Jacobsen

1991-01-01

25

Model about the separation of molecular species of hydrogen isotopes by cryogenic distillation using the elementary theory of transport phenomena  

Microsoft Academic Search

In the paper we developed a separation model for a cryogenic distillation column of hydrogen and it's isotopes, deuterium and tritium. Using the law of mass diffusion for mixtures (deduced in the frame of elementary theory of transport phenomena) we computed the components concentrations on two phases: vapor and liquid for a separation unit (theoretical plate). The multicomponent coefficients of

I. Cristescu; V. Poenariu; Irina Preda; L. Stefan

2000-01-01

26

The Distillate Bottoms Control of Distillation Columns: Modeling, Tuning and Robustness Issues  

Microsoft Academic Search

The DB (distillate-bottoms) structure was proposed by Luyben and coworkers on the basis of operators experience for the dual composition control of a distillation column. The DB structure, in regards to a relatively low volatibility and high purity column, has been indicated by the results to possess a better disturbance rejection capability over the conventional DV (distillate-vapor boilup) structure. The

DER-MING CHANG; CHENG-CHING Yu

27

Continuous and Batch Distillation in an Oldershaw Tray Column  

ERIC Educational Resources Information Center

|The importance of distillation in the separation field prompts the inclusion of distillation experiments in the chemical engineering curricula. This work describes the performance of an Oldershaw column in the rectification of a cyclohexane/n-heptane mixture. Total reflux distillation, continuous rectification under partial reflux, and batch…

Silva, Carlos M.; Vaz, Raquel V.; Santiago, Ana S.; Lito, Patricia F.

2011-01-01

28

Optimal synthesis of complex distillation columns using rigorous models  

Microsoft Academic Search

The synthesis of complex distillation columns has remained a major challenge since the pioneering work by Sargent and Gaminibanadara that was reported in 1976. In this paper we first provide a review of recent work for the optimal design of distillation of individual columns using tray-by-tray models. We examine the impact of different representations and models, NLP, MINLP and GDP,

Ignacio E. Grossmann; Pío A. Aguirre; Mariana Barttfeld

2005-01-01

29

Nonlinear model predictive control of a packed distillation column  

Microsoft Academic Search

A rigorous dynamic model based on fundamental chemical engineering principles was formulated for a packed distillation column separating a mixture of cyclohexane and n-heptane. This model was simplified to a form suitable for use in on-line model predictive control calculations. A packed distillation column was operated at several operating conditions to estimate two unknown model parameters in the rigorous and

Ashutosh A. Patwardhan; Thomas F. Edgar

1993-01-01

30

Internally Heat-Integrated Distillation Columns: A Review  

Microsoft Academic Search

The heat-integrated distillation column to be addressed in this paper is a special distillation column that involves internal heat integration between the whole rectifying and the whole stripping sections. An overview of the research on this process is presented in this work. It covers from the thermodynamic development and evaluations to the practical design and operation investigations for the process.

M. Nakaiwa; K. Huang; A. Endo; T. Ohmori; T. Akiya; T. Takamatsu

2003-01-01

31

Improved operational policies for batch extractive distillation columns  

Microsoft Academic Search

The authors and others have previously developed insights into batch distillation when using a middle vessel batch column. They extended earlier work on reachable product regions for continuous columns to this and other batch column configurations. The work also examined the use of a continuously flowing extractive agent to facilitate the separation of azeotropic mixtures. A middle vessel batch column

Boyd T. Safrit; Arthur W. Westerberg

1997-01-01

32

The setup of an extraction system coupled to a hydrogen isotopes distillation column  

SciTech Connect

Among the most difficult problems of cryogenic distillation one stands apart: the extraction of the heavy fraction. By an optimal design of the cycle scheme, this problem could be avoided. A 'worst case scenario' is usually occurring when the extracted fraction consists of one prevalent isotope such as hydrogen and small amounts of the other two hydrogen isotopes (deuterium and/or tritium). This situation is further complicated by two parameters of the distillation column: the extraction flow rate and the hold-up. The present work proposes the conceptual design of an extraction system associated to the cryogenic distillation column used in hydrogen separation processes. During this process, the heavy fraction (DT, T{sub 2}) is separated, its concentration being the highest at the bottom of the distillation column. From this place the extraction of the gaseous phase can now begin. Being filled with adsorbent, the extraction system is used to temporarily store the heavy fraction. Also the extraction system provides samples for the gas Chromatograph. The research work is focused on the existent pilot plant for tritium and deuterium separation from our institute to validate the experiments carried out until now. (authors)

Zamfirache, M.; Bornea, A.; Stefanescu, I.; Bidica, N.; Balteanu, O.; Bucur, C. [INC-DTCI, ICSIRm. Valcea, Uzinei Street 4, Rm. Valcea (Romania)

2008-07-15

33

A geometric design method for side-stream distillation columns  

Microsoft Academic Search

A side-stream distillation column may replace two simple columns for some applications, sometimes at considerable savings in energy and investment. This paper describes a geometric method for the design of side-stream columns; the method provides rapid estimates of equipment size and utility requirements. Unlike previous approaches, the geometric method is applicable to nonideal and azeotropic mixtures. Several example problems for

Raymond E. Rooks; Michael F. Malone; Michael F. Doherty

1996-01-01

34

Applying risk assessment principles to a batch distillation column  

Microsoft Academic Search

Some distillation columns in the chemical industry are operated in batch mode with a fairly short operating cycle. At the end of each cycle the columns are cooled and recharged. During the cooling cycle, air will be drawn into the column by the action of a vacuum relief valve. Consequently, for a finite portion of the operating cycle a flammable

John L. Woodward; Michael D. Moosemiller; Robert Chopp

1996-01-01

35

Improved direct and indirect systems of columns for ternary distillation  

SciTech Connect

Separation of a ternary mixture into almost pure components is discussed. Systems of distillation columns, with higher thermodynamic efficiency, are developed from a direct sequence (or indirect sequence) of distillation columns by allowing for two interconnecting streams of the same composition and different enthalpy. This increases the reversibility of distillation in the second column, which results in replacing a portion of the high-temperature boiling duty with a lower-temperature heat in the direct split case. For the indirect split case, the improvement allows a portion of the low-temperature condensing duty to be replaced with a higher-temperature condensation.

Agrawal, R.; Fidkowski, Z.T. [Air Products and Chemicals, Inc., Allentown, PA (United States)

1998-04-01

36

Tritium Isotope Separation Using Adsorption-Distillation Column  

SciTech Connect

In order to miniaturize the height of a distillation tower for the detritiation of waste water from fusion reactors, two experiments were conducted: (1) liquid frontal chromatography of tritium water eluting through an adsorption column and (2) water distillation using a column packed with adsorbent particles. The height of the distillation tower depends on the height equivalent to a theoretical plate, HETP, and the equilibrium isotope separation factor, {alpha}{sub H-T}{sup equi}. The adsorption action improved not only HETP but also {alpha}{sub H-T}{sup equi}. Since the adsorption-distillation method proposed here can shorten the tower height with keeping advantages of the distillation, it may bring an excellent way for miniaturizing the distillation tower to detritiate a large amount of waste water from fusion reactors.

Fukada, Satoshi [Kyushu University (Japan)

2005-07-15

37

A nonequilibrium model for dynamic simulation of tray distillation columns  

Microsoft Academic Search

A nonequilibrium model for the dynamic simulation of distillation columns is described. The nonequilibrium model includes the direct calculation of the rates of mass and energy transfer and is better able to model the actual physical processes occurring on a real distillation tray than is the conventional equilibrium stage model. Example calculations show that heat-transfer limitations and the vapor holdup

Hendrik A. Kooijman; Ross Taylor

1995-01-01

38

Entropy production and exergy loss in experimental distillation columns  

Microsoft Academic Search

Diabatic distillation, i.e. with heat exchangers on all trays, can increase the second law energy efficiency drastically compared to adiabatic distillation. The purpose of this research was to describe the entropy production rate in one adiabatic and one diabatic experimental water\\/ethanol rectifying column by applying the theory of irreversible thermodynamics. As a benchmark for the description, an exergy analysis of

Gelein de Koeijer; Ricardo Rivero

2003-01-01

39

Experimental study of wave propagation dynamics of multicomponent distillation columns  

SciTech Connect

Distillation columns with sharp separations exhibit severely nonlinear behavior, which has been known to cause difficulties in column control and design. Such a column is characterized by sharp composition and temperature variations in the column. Previously, the binary distillation case was thoroughly analyzed using a nonlinear wave theory and such an analysis was experimentally validated. For multicomponent distillation, the complicated nonlinear dynamics of the movement and interference of multiple sharp composition variations can be elucidated with a coherent-wave theory developed earlier for general countercurrent separation processes. With a ternary alcohol mixture, the present study has experimentally verified the theory by demonstrating the existence and propagation of constant-pattern coherent waves in a 50-tray stripping column in response to a step disturbance of feed composition, feed flow rate, or reboiler heat supply. The study has also tested the theory's predictions of composition profile, wave velocities, and asymmetric dynamics.

Ting, J.; Helfferich, F.G.; Hwang, Y.L.; Graham, G.K.; Keller, G.E. II

1999-10-01

40

Dual cascade control design for binary distillation columns  

Microsoft Academic Search

In this paper, a linear cascade scheme to control both effluent purities in binary distillation columns with temperature and delayed composition measurements is presented. First, the column input-output behavior is modeled as a set of linear integrators, driven by control inputs and reconstruction load disturbances. This control model yields a linear cascade control scheme with: (i) a purely integral decentralized

Eduardo Castellanos-Sahagún; Jesús Alvarez

2006-01-01

41

Exergetic and economic analysis of an industrial distillation column  

Microsoft Academic Search

In this work, applications of exergy and economic concepts to compression, heat exchange, and separation processes were used for calculation of the irreversibility rate, thermodynamic efficiency, and internal rate of return (IRR) of the profitability. A case study based on a real process, the purification of 1,2- dichloroethane (DCE) in a high-purity distillation column, is presented. This column has the

A. C. B. Araújo; L. G. S. Vasconcelos; M. F. Fossy; R. P. Brito

2007-01-01

42

Scale-up of reactive distillation columns with catalytic packings  

Microsoft Academic Search

The scale-up of reactive distillation columns with catalytic packings requires the knowledge of reaction kinetics, phase equilibrium and packing characteristics. Therefore, pressure drop, liquid holdup and separation efficiency have been determined for the catalytic packing MULTIPAK®. A new hydrodynamic model that describes the countercurrent gas-liquid flow for the whole loading range and considers the influence of the column diameter has

Achim Hoffmann; Christoph Noeres; Andrzej Górak

2004-01-01

43

Temperature cascade control of distillation columns  

SciTech Connect

This paper examines how difficult control tasks are enhanced by introducing secondary measurements, creating control cascades. Temperature is much used as secondary measurement because of cheap implementation and quick and accurate response. Distillation is often operated in this manner due to slow or lacking composition measurements, although the benefits have hardly been investigated closely, especially for multivariable control applications. The authors therefore use distillation as the example when quantifying improvements in interaction and disturbance rejection. They also give analytical expressions for the secondary controller gain. The improvements are reached through simple cascade operation of the control system and require no complicated estimator function.

Wolff, E.A.; Skogestad, S. [Univ. of Trondheim (Norway). Dept. of Chemical Engineering

1996-02-01

44

Temperature–enthalpy curve for energy targeting of distillation columns  

Microsoft Academic Search

The temperature–enthalpy (T–H) diagram of a distillation column at practical near-minimum thermodynamic condition (PNMTC) or the column grand composite curve (CGCC) is a useful representation for energy targeting studies and may be generated from a converged simulation of a base-case column design. The calculation procedure for the CGCC involves determination of the net enthalpy deficit at each stage by generating

Santanu Bandyopadhyay; Ranjan K. Malik; Uday V. Shenoy

1998-01-01

45

Self-Tuning Control of Distillation Columns: Theory and Practice  

Microsoft Academic Search

An experimental evaluation of multivariable self-tuning control algorithms for the simultaneous control of both top and bottom product compositions of a binary distillation column is presented. The study was carried out using an 8-tray, 30.5 cm diameter methanol-water pilot scale column. The column is controlled using an LSI 11\\/03 microcomputer with continuous capacitance analysis of top product composition and with

F. Vagi; R. K. Wood; A. J. Morris; M. Tham

1985-01-01

46

Dynamic and Steady State Behaviour of an Extractive Distillation Column  

Microsoft Academic Search

This project was the second part of a long-term study into the control of an extractive distillation unit. A fifteen stage extractive distillation column was re-built and operated over a range of operating levels. Overhead product acetone composition was limited to approximately 0.94 mole fraction acetone due to tray liquid priming. A steady state simulation was developed to aid in

Dwayne L. ONeill

1975-01-01

47

Minimum-reflux regime of simple distillation columns  

Microsoft Academic Search

A general algorithm for calculating minimum reflux ratios in simple distillation columns used for the separation of ideal\\u000a and nonideal (including azeotropic) homogeneous multicomponent mixtures is proposed. The algorithm deals with various splits:\\u000a direct, indirect, intermediate, and with one distributed component. The algorithm is mathematically rigorous, developed on\\u000a the basis of the geometrical theory of distillation, and makes it possible

R. Yu. Danilov; F. B. Petlyuk; L. A. Serafimov

2007-01-01

48

Kinetic azeotropy and design of reactive distillation columns  

SciTech Connect

The reactive fixed points in the distillation maps of a reactive distillation column (RDC) with kinetically controlled reactions are identified and their role in deciding the design feasibility has been elucidated. The fixed points at which both reaction and distillation vectors have zero magnitudes correspond to the equilibrium fixed point. It is known that the relative positions of these points for the rectifying and stripping sections determine the value of the minimum reflux ratio. However, apart from these fixed points, there are certain fixed points in the distillation map at which, though the reaction and distillation vectors have nonzero magnitudes, they nullify the effects of each other. These points correspond to the kinetic fixed points and have a special significance. Their positions have direct influence on the feasible product composition. A simple example of an ideal ternary system undergoing a reaction 2B {longleftrightarrow} A + c has been illustrated to show the importance of kinetic azeotropy in the design aspects of RDC.

Mahajani, S.M. [Monash Univ., Clayton, Victoria (Australia). Dept. of Chemical Engineering

1999-01-01

49

Improved operational policies for batch extractive distillation columns  

SciTech Connect

The authors and others have previously developed insights into batch distillation when using a middle vessel batch column. They extended earlier work on reachable product regions for continuous columns to this and other batch column configurations. The work also examined the use of a continuously flowing extractive agent to facilitate the separation of azeotropic mixtures. A middle vessel batch column has both an enriching and stripping section and thus both a distillate and bottoms product. In many ways it is just like a traditional continuous column, but the authors feed it by charging a middle tray having a very large holdup (a pot or still) with the initial feed. The work compared running this column with running a batch rectifier for an azeotropic mixture when using an extractive agent. They showed that both are often able in theory to recover all of the distillate component in relatively pure form, with the middle vessel accomplishing this by steering the still pot composition against time through the choice of reflux, reboil, entrainer, and product rates. The middle vessel also requires a much smaller pot, as the authors can continually remove and recycle the extractive agent. In this work the authors show the sensitivity of the separation`s profit to the entrainer flow rate, the operation`s switching times between fractions, and the bottom flow rate policy for an extractive middle vessel batch column. They illustrate with an example problem.

Safrit, B.T.; Westerberg, A.W. [Carnegie Mellon Univ., Pittsburgh, PA (United States)

1997-02-01

50

Multivariable control of an energy-integrated distillation column  

SciTech Connect

Distillation columns that have design modifications for the purpose of more efficient-energy utilization are often complex systems which present difficult process control problems. The work discusses the theory and development of several algorithms that offer improved controller responses and operational flexibility. One of the major contributions of this work is the development of methods where the number of manipulated variables exceeds the number of controlled variables. The system is a binary distillation column equipped with an intermediate heat exchanger that partially condenses vapors in the rectifying section of the column. This intermediate condenser allows a portion of the energy expended in the reboiler to be recovered at a useful temperature. The inter-condenser heat duty was examined for use as an extra process control input, used for regulating the distillate and bottoms product compositions, which were the controlled variables. Both conventional energy balance control pairing and material balance pairing were examined in conjunction with the intermediate condenser system. Three different controller algorithms were developed for designing non-square process controllers; a switching MVSISO method, multivariable optimal control, and structural compensation were implemented on a computer simulation of the distillation unit. A second part of the research is the development of accurate low order models for distillation systems. In particular, a reduced order, compartmental modeling approach was investigated for simulation and process control applications. This research identified critical parameters of the compartmental model which affect the accuracy of the resulting low order dynamic model.

Horton, R.R.

1987-01-01

51

An indirect feedforward composition controller for distillation columns  

Microsoft Academic Search

This paper addresses the problem of designing an indirect feedforward controller, also called cascade control, to regulate the product composition of distillation columns to overcome load disturbances. The overall controller is composed of two cascaded controllers. The primary controller is basically a low-gain controller, which uses slow (delayed) composition measurements to provide servo responses (composition control). The secondary controller has

Rosendo Monroy-Loperena; Jose Alvarez-Ramirez

2002-01-01

52

A geometric design method for side-stream distillation columns  

SciTech Connect

A side-stream distillation column may replace two simple columns for some applications, sometimes at considerable savings in energy and investment. This paper describes a geometric method for the design of side-stream columns; the method provides rapid estimates of equipment size and utility requirements. Unlike previous approaches, the geometric method is applicable to nonideal and azeotropic mixtures. Several example problems for both ideal and nonideal mixtures, including azeotropic mixtures containing distillation boundaries, are given. The authors make use of the fact that azeotropes or pure components whose classification in the residue curve map is a saddle can be removed as side-stream products. Significant process simplifications are found among some alternatives in example problems, leading to flow sheets with fewer units and a substantial savings in vapor rate.

Rooks, R.E.; Malone, M.F.; Doherty, M.F. [Univ. of Massachusetts, Amherst, MA (United States). Dept. of Chemical Engineering

1996-10-01

53

Experimental study of wave propagation dynamics of binary distillation columns  

SciTech Connect

High-purity distillation columns are typically difficult to control because of their severely nonlinear behavior reflected by their sharp composition and temperature profiles. The dynamic behavior of such a column, as characterized by the movement of its sharp profile, was elucidated by a nonlinear wave theory established previously. With binary alcohol mixtures, this study provides an experimental observation of such wave-propagation dynamics of a 40-tray stripping column and a 50-tray fractionation column in response to step disturbances of feed composition, feed flow rate, and reboiler heat supply. These experimental results have verified that the sharp profile in a high-purity column moves as a constant-pattern wave and that the nonlinear wave theory predicts its velocity satisfactorily with very simple mathematics. Results also demonstrate the asymmetric dynamics of the transitions between two steady states.

Hwang, Y.L.; Graham, G.K.; Keller, G.E. II [Union Carbide Corp., South Charleston, WV (United States); Ting, J.; Helfferich, F.G. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Chemical Engineering

1996-10-01

54

A nonequilibrium model for dynamic simulation of tray distillation columns  

SciTech Connect

A nonequilibrium model for the dynamic simulation of distillation columns is described. The nonequilibrium model includes the direct calculation of the rates of mass and energy transfer and is better able to model the actual physical processes occurring on a real distillation tray than is the conventional equilibrium stage model. Example calculations show that heat-transfer limitations and the vapor holdup above the froth cannot be neglected at elevated pressures. Back-computed Murphree tray efficiencies are not constant over time, which implies that the equilibrium model should not be used for dynamic simulations.

Kooijman, H.A.; Taylor, R. [Clarkson Univ., Potsdam, NY (United States). Dept. of Chemical Engineering

1995-08-01

55

A general distillation modeling framework applied to an isotopic distillation column  

Microsoft Academic Search

Being one of the most approached subjects in the field of chemical engineering, a lot of numerical modeling methods for the distillation columns were presented in scientific papers. This means that in order to find a model that would suit a specific process requires a considerable amount of time. This paper will present a general first principle model that aims

Ionut Muntean; Maxim Stuckert; Mihail Abrudean

2011-01-01

56

Cryogenic focussing, ohmically heated on-column trap  

SciTech Connect

A procedure is described for depositing a conductive layer of gold on the exterior of a fused-silica capillary used in gas chromatography. By subjecting a section of the column near the inlet to a thermal cycle of cryogenic cooling and ohmic heating, volatile samples are concentrated and subsequently injected. The performance of this trap as a chromatographic injector is demonstrated. Several additional applications are suggested and the unique properties of this device are discussed. 11 refs., 5 figs., 1 tab.

Springston, S.R.

1991-12-01

57

THE THEORY OF THE NON-STATIONARY BEHAVIOR OF DISTILLATION COLUMNS  

Microsoft Academic Search

In order to be able to control distillation columns in an optimum ; manner, it is necessary to investigate the behavior of the distillation column at ; control intervals. The behavior of a 5- and a 30-stage distillation column was ; investigated for imposed fluctuations of the initiai concentrations. (trauth);

G. Voigt; O. Gebhardt

1962-01-01

58

Applying risk assessment principles to a batch distillation column  

SciTech Connect

Some distillation columns in the chemical industry are operated in batch mode with a fairly short operating cycle. At the end of each cycle the columns are cooled and recharged. During the cooling cycle, air will be drawn into the column by the action of a vacuum relief valve. Consequently, for a finite portion of the operating cycle a flammable mixture will exist in the column. Here we evaluate the risk posed by such an operation to see if a mitigation measure is justified. We develop a fault tree and estimate the frequency of ignition by all possible ignition sources. By comparing the risk reduction attainable by installing a lightning protection system with that attainable by using an inert blanketing system the lightning protection system is found to be the preferred solution. It provides about the same risk reduction at a lower overall cost. 2 refs., 3 figs., 4 tabs.

Woodward, J.L.; Moosemiller, M.D. [DNV Technica, Columbus, OH (United States)

1996-12-31

59

Fuzzy Control of Distillation Columns with and without Side Streams  

Microsoft Academic Search

\\u000a Besides the classical control theories the method of fuzzy control gains increasing interest. A great number of publications\\u000a deals with this topic describing it as very efficient concept. In this paper the development of control systems based upon\\u000a fuzzy control theory for distillation columns with and without sidestreams is pointed out. The performance of this control\\u000a application is compared to

Chr. Remberg; G. Fieg; G. Wozny; F. N. Fett

60

Demonstration of ``regulatory`` process controls on the TSTA cryogenic distillation system  

SciTech Connect

Due to the nature of its fusion reaction, most of the DT used to fuel the International Thermonuclear Experimental Reactor (ITER) will exit unreacted. This effluent will be purified by the fuel cleanup system so that the isotope separation system (ISS) will be fed only hydrogen isotopes and possibly some helium. The ISS will separate this feed into streams nominally composed of He/H2/HD, D2, DT, and T2. These products will be recycled through appropriate fueling systems back to the fusion reactor or returned to storage. The ISS will have to respond properly to feed conditions which change rapidly. Feed changes will propagate quickly through the entire cascade. It is apparent that an automatic control system will be required to respond to these changes and maintain product quality. It is convenient to divide such a distillation control system into `regulatory` controls and composition controls. The `regulatory` controls include liquid levels, flowrates, reboiler heats, and pressure. A system of regulatory controls has been devised and installed on the four-column cascade of cryogenic columns at the Tritium Systems Test Assembly (TSTA) at Los Alamos National Laboratory. This tritium-compatible ISS is designed for approximately 1/10 the ITER flowrate and is dedicated to fusion fuel studies. Details of the TSTA ISS have been published previously.

Willms, R.S.; Sherman, R.H.; Cole, S.P.; Riggs, J.B.; Okuno, K.

1995-04-01

61

The second law optimal state of a diabatic binary tray distillation column  

Microsoft Academic Search

A new numerical procedure to minimize the entropy production in diabatic tray distillation columns has been developed. The method was based on a least square regression of the entropy production at each tray. A diabatic column is a column with heat exchangers on all trays. The method was demonstrated on a distillation column separating propylene from propane. The entropy production

A. Røsjorde; S. Kjelstrup

2005-01-01

62

Air separation process using packed columns for oxygen and argon recovery  

Microsoft Academic Search

This patent describes an improvement in a process for the separation of mixtures, which comprise oxygen, nitrogen, and argon, by cryogenic distillation in an integrated multi-column distillation system of at least three distillation columns, having a higher pressure column, low pressure column and an argon sidearm column. Wherein the argon sidearm column integrally communicates with the low pressure column. Wherein

R. M. Thorogood; D. L. Bennett; R. J. Allam; A. L. Prentice; B. K. Dawson

1989-01-01

63

Experimental study on pressure drops in a dividing wall distillation column  

Microsoft Academic Search

Previous studies in the fields of process design and process control [1] have shown the potential benefits that can be achieved through the implementation of thermally coupled distillation sequences, in particular, the dividing wall distillation column. The dividing wall distillation column meets important goals of process intensification, including energy savings, reduction in carbon dioxide emissions and miniaturization. In this paper,

Fabricio Omar Barroso-Muñoz; Salvador Hernández; Héctor Hernández-Escoto; Juan Gabriel Segovia-Hernández; Vicente Rico-Ramírez; Rosa-Hilda Chavez

2010-01-01

64

Cryogenic distillation: a fuel enrichment system for near-term tokamak-type D-T fusion reactors  

SciTech Connect

The successful operation and economic viability of deuterium-tritium- (D-T-) fueled tokamak-type commercial power fusion reactors will depend to a large extent on the development of reliable tritium-containment and fuel-recycle systems. Of the many operating steps in the fuel recycle scheme, separation or enrichment of the isotropic species of hydrogen by cryogenic distillation is one of the most important. A parametric investigation was carried out to study the effects of the various operating conditions and the composition of the spent fuel on the degree of separation. A computer program was developed for the design and analysis of a system of interconnected distillation columns for isotopic separation such that the requirements of near-term D-T-fueled reactors are met. The analytical results show that a distillation cascade consisting of four columns is capable of reprocessing spent fuel varying over a wide range of compositions to yield reinjection-grade fuel with essentially unlimited D/T ratio.

Misra, B.; Davis, J.F.

1980-02-01

65

Dividing wall distillation columns for separation of azeotropic mixtures: feasibility procedure and rigorous optimization  

Microsoft Academic Search

In this work, we propose the use of dividing wall distillation columns, DWC, to separate azeotropic mixtures. First, we present a procedure to guarantee the feasibility of the desired split, based on material balances. Once the feasibility is verified, a preliminary design is calculated considering the DWC as an arrangement of three disengaged conventional distillation columns. Then, this design is

Abel Briones-Ramírez; Claudia Gutiérrez-Antonio

2009-01-01

66

Short-cut methods for the optimal design of simple and complex distillation columns  

Microsoft Academic Search

New short-cut methods providing optimal design parameters for distillation columns with simple and complex configurations including two-feed and one-feed-one-side-stream columns are presented. The methods assume constant relative volatilities and constant molar flow rates within each distillation section. The design equations are based on the Underwood equations for the calculation of minimum reflux (reboil) ratio, the analytical formulations of the distillation

Chafika Adiche; Alfons Vogelpohl

2011-01-01

67

The product composition regions of azeotropic distillation columns. 2. Separability in two-feed columns and entrainer selection  

Microsoft Academic Search

A method to assess the product composition regions for distillation of ternary mixtures in single-feed distillation columns, introduced in the first paper of this series, is generalized to account for the effect of introducing multiple feeds of different trays. The method relies on so-called fixed point curves which are trajectories in the compositions space. These trajectories describe the possible compositions

Oliver M. Wahnschafft; Arthur W. Westerberg

1993-01-01

68

A design method for internal heat integrated distillation columns (iHIDiCs)  

Microsoft Academic Search

Distillation of close-boiling mixtures, such as propylene-propane and ethyl benzene-styrene systems, is an energy intensive process. Vapor recompression (VRC) techniques and heat pumping-assisted columns have been adopted for such applications for their high potential of energy savings. In direct vapor recompression columns, the vapor leaving the top of the distillation column is compressed and then it is condensed in the

Mamdouh Gadalla; Zarko Olujic; Laureano Jiménez Esteller; Gonzalo Guillén-Gosálbez

2007-01-01

69

The separation study of hydrogen isotopes with Cryogenic-Wall thermal diffusion column  

SciTech Connect

The thermal diffusion is one of the useful methods of the hydrogen isotope separation. This paper reports on the experiments using Cryogenic-Wall thermal diffusion column cooled by liquid nitrogen which have been performed in the total reflux and the withdraw modes. As using the same inner diameter column, Cryogenic-Wall thermal diffusion column has the higher separation factor, but the lower optimum pressure than Ordinary-Wall thermal diffusion column cooled by water. It is obtained that Cryogenic-Wall column with a smaller inner diameter has the remarkable high separation factor and the higher optimum pressure. In the withdraw mode, the characteristics of the separation factor as a function of the feed rates is obtained about the several inner diameter columns.

Okada, Y.; Sakai, F.; Mitsui, J. (Sumitomo Heavy Industries Ltd., Hiratsuka (Japan))

1992-03-01

70

Startup of distillation columns using profile position control based on nonlinear wave model  

SciTech Connect

Startup of distillation columns is a very challenging control problem because of its strong nonlinearity and a wide operating range during the transient period. A nonlinear wave model captures the essential dynamic behavior of the distillation process so that it is possible to deal with the difficulties encountered during startup operation. This paper is concerned with the startup of distillation systems using nonlinear wave model based control developed by Han and Park. This control scheme uses profile positions as controlled variables and is based on the nonlinear wave model by Hwang and generic model control scheme by Lee and Sullivan. It can be applied to a binary or a multicomponent distillation system that can be represented as a pseudobinary. The proposed control scheme is shown by simulation studies to provide a safe and economic startup operation not only for dual composition control of a simple distillation column but also for a complex distillation configuration.

Han, M.; Park, S. [Chungnam National Univ., Taejon (Korea, Republic of). Chemical Engineering Dept.]|[Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of). Chemical Engineering Dept.

1999-04-01

71

Thermodynamically equivalent distillation schemes to the Petlyuk column for ternary mixtures  

Microsoft Academic Search

Thermally coupled distillation sequences for ternary separations have been shown to provide significant energy savings with respect to the conventional direct and indirect distillation sequences. Although the Petlyuk column is generally more efficient than the other thermally coupled schemes, its structure creates potential operating problems because of the bi-directional vapour interconnecting streams. In this paper, second law calculations were performed

Salvador Hernández; Juan Gabriel Segovia-Hernández; Vicente Rico-Ramírez

2006-01-01

72

A generalized model for distillation columns—I Model description and applications  

Microsoft Academic Search

AM-A generalized model for the dynamic simulation of distillation columns is presented. The model allows the solution of a wide variety of problems, from open- and closed-loop responses of single (and multiple) columns to operability studies (of feed changeover and start-up operations) and column instability studies (effect of plate hydraulics during transient operations). Results are given for single columns (including

R. GANI; I. T. CAMERONS

1986-01-01

73

Internal heat integrated distillation columns (iHIDiCs)—New systematic design methodology  

Microsoft Academic Search

Distillation of close-boiling mixtures, such as propylene–propane and ethyl benzene–styrene systems, is an energy intensive process. Vapor recompression techniques and heat pumping-assisted columns have been adopted for such applications for their high potential of energy savings. In direct vapor recompression columns, the vapors leaving the top of the column are compressed, and in the reboiler of the same column, these

Mamdouh A. Gadalla

2009-01-01

74

Assessing Safety in Distillation Column Using Dynamic Simulation and Failure Mode and Effect Analysis (FMEA)  

NASA Astrophysics Data System (ADS)

Safety assessment becomes an important activity in chemical industries since the need to comply with general legal requirements in addition to meet safer plant and profit. This paper reviews some most frequently causes of distillation column malfunction. First, analysis of case histories will be discussed for providing guidelines in identifying potential trouble spots in distillation column. A dynamic simulation for operational failure is simulated as the basis for assessing the consequences. A case study will be used from a side stream distillation column to show the implementation of the concept. A framework for assessing safety in the column is proposed using Fault Mode and Effect Analysis (FMEA). Further, trouble-free operation in order to reduce the risk associated with column malfunction is described.

Werner, Suhendra; Fred, Witt; Compart

75

Towards further internal heat integration in design of reactive distillation columns—Part IV: Application to a high-purity ethylene glycol reactive distillation column  

Microsoft Academic Search

In the first three papers of this series, it has been shown that strengthening internal heat integration within a reactive distillation column involving reactions with high thermal effect is really effective for the reduction of utility consumption and capital investment besides the improvement in process dynamics and operation. One important issue that remains unstudied so far is the influences of

Fanghong Zhu; Kejin Huang; Shaofeng Wang; Lan Shan; Qunxiong Zhu

2009-01-01

76

APSA: A new cape tool for design and troubleshooting of azeotropic distillation columns  

Microsoft Academic Search

The azeotrope pressure sensitivity analysis (APSA) provides a dependence of compositions and temperatures of azeotropes with respect to changes in pressure. This information can be of critical importance in the design and troubleshooting of real distillation columns, especially when there is a substantial pressure drop in the column. In some cases, this can lead to a switch in topology of

Stanislaw K. Wasylkiewicz

2004-01-01

77

The Influence of Heat Transfer Irreversibilities on the Optimal Performance of Diabatic Distillation Columns  

Microsoft Academic Search

A distillation column with the possibility of heat exchange on every tray (a fully diabatic column) is optimized in the sense of minimizing its total entropy production. This entropy production counts the interior losses due to heat and mass flow as well as the entropy generated in the heat exchangers. It is observed that the optimal heating distribution, i.e. the

M. Schaller; K. H. Hoffmann; R. Rivero; B. Andresen; P. Salamon

2002-01-01

78

Implementation of a reactive dividing wall distillation column in a pilot plant  

Microsoft Academic Search

Based on the knowledge regarding steady state design, optimization and control obtained by using Aspen Plus and Aspen Dynamics process simulators, we have designed and implemented a reactive dividing wall distillation column (DWDC). The column can be used to carry out the equilibrium reaction between ethanol and acetic acid to produce ethyl acetate and water catalyzed by sulfuric acid. The

Rodrigo Sandoval-Vergara; Fabricio Omar Barroso-Muñoz; Héctor Hernández-Escoto; Juan Gabriel Segovia-Hernández; Salvador Hernández; Vicente Rico-Ramírez

2008-01-01

79

Modeling and control of a packed distillation column using artificial neural networks  

Microsoft Academic Search

Artificial neural networks, because they are nets of basis functions, can provide good empirical models of complex nonlinear processes that are useful for many purposes including process control. The modelling of a packed distillation column described here provides an interesting example of complex modeling because the column exhibits a change in the sign of the gain under various operating conditions.

J. C. Macmurray; D. M. Himmelblau

1995-01-01

80

Steady States of the Reactor–Distillation Column System for an A + B ? C Reaction  

Microsoft Academic Search

The steady states of the reactor-distillation column recycle system are analyzed for the reaction A + B ? C at various feed compositions. The analysis is performed for an infinite column operated at total reflux. If the lightest component, A, is in excess, the complete conversion of the medium-boiling component, B, is impossible. If reactant B is in excess, there

S. L. Nazanskii; A. V. Solokhin; S. A. Blagov; V. S. Timofeev

2001-01-01

81

Heat Transfer Study of Heat-Integrated Distillation Column (HIDiC) Using Simulation Techniques  

NASA Astrophysics Data System (ADS)

Separation processes is largely used in petroleum refining and alcohol industries. Distillation columns consume a huge amount of energy in industrial process. Therefore, the concept of Heat-Integrated Distillation Column (HIDiC) was studied using simulation techniques in order to overcome this drawback. In this configuration the column is composed for two concentric sections called rectifying and stripping. The heat transfer is conducted from the rectifying section (which works at higher pressure and temperature) to the stripping section (which works at lower pressure and temperature) using the heat present in the process and decreasing the energy charge required by the reboiler. The HIDiC column offers great potential to reduce energy consumption compared to conventional columns. However, the complexity of the internal configuration requires the development of rigorous works that enable a better understanding of the column operation. For this reason, techniques of simulation were used through of computational software. The current work presents a heat transfer study in a concentric stage of a HIDiC column. The results obtained by Aspen Plus and CFD simulation showed the internal heat transfer in a concentric tray as a promissory configuration in order to decrease energy consumption in distillation processes.

Pulido, Jeffrey León; Martínez, Edgar Leonardo; Wolf, Maria Regina; Filho, Rubens Maciel

2011-08-01

82

Distillation Columns with Structured Packings in the Next Decade  

Microsoft Academic Search

The analysis of the history of structured packings allows the conclusion that the inno- vation cycle will become faster. Based on the separation power as an alternative way to represent the performance characteristics an estimate of the next level of what might be the ultimative separa- tion power is given. Regarding the column internals like distributors only slight improvements are

Lothar Spiegel; Werner Meier

2003-01-01

83

The effects of thermodynamic data on the design and operation of distillation columns  

Microsoft Academic Search

The relative importance of various physical properties for distillation-column design and operation is classified. Vapor-liquid equilibrium data have a dominant effect. It is possible to quantify the effect of errors of relative volatility on the uncertainty of the number of stages required for a given simple binary separation problem by using the simplest, so-termed short-cut methods of column design, because

Zeck

1993-01-01

84

Operation of a batch distillation column with a middle vessel: experimental results for the separation of zeotropic and azeotropic mixtures  

Microsoft Academic Search

Batch distillation in a column with a middle vessel can avoid many of the disadvantages associated with the regular batch distillation processes. In this paper, we present an experimental investigation of the separation of a zeotropic ternary mixture via total reflux operation and of the separation of an azeotropic binary mixture via batch-wise extractive distillation. Moreover, the results obtained for

M. Warter; D. Demicoli; J. Stichlmair

2004-01-01

85

Integration of reaction and separation in a batch extractive distillation column with a middle vessel  

Microsoft Academic Search

In this work, the integration of reaction and separation in a batch extractive distillation column with a middle vessel\\/reactor is analyzed for azeotrope-forming mixtures. This equipment configuration has the potential to promote complete conversion of reactants and therefore, the main process characteristics are investigated. A mixture showing several azeotropes and suffering an esterification reaction was selected as an academic example.

José Espinosa

2002-01-01

86

Control strategies analysis for a batch distillation column with experimental testing  

Microsoft Academic Search

The dynamic nature and the non-linear behaviour of batch distillation equipment pose challenging control system design when products of constant purity are to be recovered. Several alternative column configurations and operating policies have been studied. However, issues related to the on-line operation of such process have not been properly addressed. The present work describes the investigation with experimental verification of

Ana M Frattini Fileti; Sandra L Cruz; João A. F. R Pereira

2000-01-01

87

Prediction of the Trayed Distillation Column Mass-Transfer Performance by Neural Networks  

Microsoft Academic Search

The sieve-tray distillation column mass-transfer efficiency was successfully modeled using a neural network. The database developed by Garcia and Fair (Ind. Eng. Chem. Res. 2000, 39, 1809) was utilized to train and validate the neural network model. The results indicate that, if the system is similar to the data used to train the neural network, the purely empirical neural network

Eric Olivier; R. Bruce Eldridge

2002-01-01

88

Counter-current operation of structured catalytically packed distillation columns: pressure drop, holdup and mixing  

Microsoft Academic Search

Structured packed columns, in which the catalyst particles are enclosed within wire gauze envelopes (“sandwiches”) are promising reactor configurations for reactive distillation and hydroconversions. By allowing preferential channels for the gas and liquid phases, counter-current operation is achieved even for millimeter sized catalyst particles without the problem of flooding. This paper reports the results of a comprehensive experimental study of

J. Ellenberger; R. Krishna

1999-01-01

89

Excess Methanol Recovery in Biodiesel Production Process Using a Distillation Column: A Simulation Study  

Microsoft Academic Search

This paper presents an ASPEN PLUS TM simulation study for excess methanol recovery in continuous biodiesel production process using a distillation column. The feedstock used for biodiesel production was Triolein containing 15% free fatty acid (Oleic Acid). The special attention was devoted to the e ect of di erent alcohol to oil ratio and important design and operating parameters of

Bipro Ranjan Dhar; Kawnish Kirtania

2009-01-01

90

Distillation columns containing structured packings: A comprehensive model for their performance. 2: Mass-transfer model  

Microsoft Academic Search

This is the second part of a two-part paper dealing with the fluid mechanics and mass transfer in structured packings for distillation column service. The first part elucidated pressure drop, flooding, and liquid holdup. The second part covers the generation of effective interfacial area and provides a general correlation for predicting the mass-transfer efficiency as a function of surface type,

J. Antonio Rocha; Jose L. Bravo; James R. Fair

1996-01-01

91

Distillation columns containing structured packings: A comprehensive model for their performance. 1. Hydraulic models  

Microsoft Academic Search

A mechanistically-based model has been developed to aid the analysis and design of distillation columns containing structured packings of the corrugated plate type. The model encompasses the important, and related, parameters of liquid holdup, pressure drop, flooding, and mass-transfer efficiency. Since it deals with the countercurrent contacting of liquid with gas or vapor, the model may also be applied to

J. Antonio Rocha; Jose L. Bravo; James R. Fair

1993-01-01

92

Control of high-purity distillation column using a nonlinear wave theory  

Microsoft Academic Search

A new model-based controller for profile position control of high-purity distillation columns is presented. The controller has been developed by incorporating nonlinear wave model into the generic model control framework. An observer based on the nonlinear wave theory is also proposed to determine the profile position. The performance of the nonlinear control scheme has been tested in simulation experiments of

Myungwan Han

1993-01-01

93

Transient Response of a Distillation Column Plate. Part I. Theory: Five Models and Their Fourier Transforms  

Microsoft Academic Search

Five models are used to describe the transient behavior of the liquid composition on a distillation column bubble cap tray when the liquid composition entering the tray undergoes a composition transient. The assumptions required for the models are discussed. The equations are transformed by the Laplace operator, and the solutions are left in the frequency response form for comparison with

Chester N. Sittel Jr; Gerald T. Fisher

1973-01-01

94

Control of high-purity distillation column using a nonlinear wave theory  

SciTech Connect

A new model-based controller for profile position control of high-purity distillation columns is presented. The controller has been developed by incorporating nonlinear wave model into the generic model control framework. An observer based on the nonlinear wave theory is also proposed to determine the profile position. The performance of the nonlinear control scheme has been tested in simulation experiments of high-purity binary distillation columns. Tight control of profile position, which leads to fast stabilization of product compositions, has been achieved. Since the profile position control alone produces a slight offset from the desired product concentration, the composition/profile position cascade system has been used to remove the offset. The control scheme can handle significant disturbances and model-plant mismatch.

Han, Myungwan; Park, Sunwon (KAIST, Taejon (Korea, Republic of))

1993-05-01

95

The effects of thermodynamic data on the design and operation of distillation columns  

SciTech Connect

The relative importance of various physical properties for distillation-column design and operation is classified. Vapor-liquid equilibrium data have a dominant effect. It is possible to quantify the effect of errors of relative volatility on the uncertainty of the number of stages required for a given simple binary separation problem by using the simplest, so-termed short-cut methods of column design, because the results obtained are, practically, the same as those found by more sophisticated methods. The same error in the relative volatility [alpha] leads to a sharply increasing uncertainty in the number of stages required as the value of [alpha] approaches unity.

Zeck, S. (BASF Aktiengesellschaft, Ludwigshafen (Germany))

1993-04-01

96

Fatty acid fractionation by column distillation: Purity, energy consumption and operating conditions  

Microsoft Academic Search

This paper discusses the optimal process conditions for production of individual fatty acids of any desired purity up to higher\\u000a than 99% and describes especially the influences of column internals as well as exchange numbers, reflux ratios and fatty\\u000a acid residence times at distillation temperatures. The new process conditions are characterized by degasification at low temperatures\\u000a followed by efficient dehydration

Hermann Stage

1984-01-01

97

CFD modeling of mass-transfer processes in randomly packed distillation columns  

Microsoft Academic Search

The volume-averaged equations for velocity and concentration fields have been used to simulate the hydrodynamics and mass-transfer processes in randomly packed distillation columns. This approach is regarded as a second-generation computational fluid dynamics (CFD) based model, and a significant departure from the traditional one-dimensional, first-generation models. The model has ability to capture radial and axial variations in flow and mass-transfer

F. H. Yin; C. G. Sun; A. Afacan; K. Nandakumar; K. T. Chuang

2000-01-01

98

Azeotropic distillation in a middle vessel batch column. 1: Model formulation and linear separation boundaries  

SciTech Connect

A mathematical model for the middle vessel batch distillation column (MVC) is developed using the concept of warped time analysis and used to study the qualitative dynamics of the MVC when it is used to separate multicomponent azeotropic mixtures. A limiting analysis is then developed for a MVC with an infinite number of trays, operated under infinite reflux/reboil ratios, under the assumption of linear separation boundaries. It is determined that, under limiting conditions, the distillate product drawn from the MVC is given by the {alpha} limit set of the MVC still pot composition, while the bottoms product drawn from the MVC is given by the {omega} limit set of the MVC still pot composition. The net product composition is determined by taking a convex combination of the two products. The notions of steering the still pot composition, the vector cone of possible motion for the still pot composition, and the equivalency of the MVC to the combined operation of a batch rectifier and a stripper are also explored. The definition of batch distillation regions for the MVC operated at a given value of the middle vessel parameter {lambda}, and the bifurcation of these regions with the variation of {lambda}, are investigated. Lastly, a mathematical model incorporating the concept of warped time is developed for a multivessel column. The MVC can be viewed as a specific case of the multivessel column.

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

1999-04-01

99

Towards further internal heat integration in design of reactive distillation columns—part I: The design principle  

Microsoft Academic Search

The thermodynamic efficiency of a reactive distillation column involving reactions with a highly thermal effect could sometimes be improved substantially through seeking further internal heat integration between the reaction operation and separation operation. Prudent arrangement of the reactive section and deliberate determination of feed location are the two effective methods that can complement internal heat integration within a reactive distillation

Kejin Huang; Koichi Iwakabe; Masaru Nakaiwa; Atsushi Tsutsumi

2005-01-01

100

Model reduction and optimization of a reactive dividing wall batch distillation column inspired by response surface methodology and differential evolution  

Microsoft Academic Search

Carrying out reaction and separation simultaneously in a reactive dividing wall batch distillation column batch RDWC in the case of ethyl acetate synthesis provides the possibility of separating both products and increasing the equilibrium reaction conversion. Overcoming the known azeotrope conditions, high purity for ethyl acetate and decreasing the batch time compared to simple reactive batch distillation are the advantages

Maysam Safe; Seyed Masoom Khazraee; Payam Setoodeh; Abdolhosein H. Jahanmiri

2012-01-01

101

Flooding characteristics of packed columns with high efficiency. [SDC protruded distillation, Podbielniak bronze Helipak, Norton pall ring, Goodloe mesh  

Microsoft Academic Search

Flooding characteristics of four high efficiency column packings, including Scientific Development Co. (SDC) protruded stainless distillation packing, Norton stainless pall rings, Podbielniak bronze Helipak, and Goodloe stainless wire mesh packing were determined experimentally. Two Plexiglas columns (6.35 cm ID and 15.2 cm ID) filled with these packings were operated with countercurrent air and water streams. Pressure drop data were recorded

W. M. Choi; R. C. Michel; J. L. P. Varlet

1976-01-01

102

Design concept of cryogenic falling liquid film helium separator  

Microsoft Academic Search

A design concept is developed for a cryogenic falling liquid film helium separator by clarifying the differences between this process and a cryogenic distillation column. The process characteristics are greatly improved by the idea of adding an Hâ gas flow to a point near the upper end of the packed section. The flow rate of tritium lost from the top

M. Kinoshita; T. Yamanishi; J. R. Bartlit; R. H. Sherman

1986-01-01

103

A new and applicable method to calculate mass and heat transfer coefficients and efficiency of industrial distillation columns containing structured packings  

Microsoft Academic Search

Most of the methods developed for efficiency estimation of distillation columns were based on the empirical mass transfer and hydraulic relations correlated to laboratory data. Therefore, these methods cannot estimate efficiency of industrial columns with sufficient accuracy. In this paper, a new and applicable method was developed for calculation of efficiency (and mass and heat transfer coefficients) of distillation columns

Hamidreza Sadeghifar; Ali Akbar Safe Kordi

2011-01-01

104

Distillation  

NSDL National Science Digital Library

Science in its earliest beginnings consisted of a practice called alchemy. Alchemy includes the study of chemistry, biology, astronomy, spirituality, physics, and art. Distillation or experiments in purification of substances may have been a part of the practice of alchemy.

N/A N/A (None;)

2005-12-24

105

Advances in Cryogenic Principles  

NASA Astrophysics Data System (ADS)

During the past 50 years, the use of digital computers has significantly influenced the design and analysis of cryogenic systems. At the time when the first Cryogenic Engineering Conference was held, thermodynamic data were presented in graphical or tabular form (the "steam table" format), whereas thermodynamic data for cryogenic system design is computer generated today. The thermal analysis of cryogenic systems in the 1950s involved analytical solutions, graphical solutions, and relatively simple finite-difference approaches. These approaches have been supplanted by finite-element numerical programs which readily solve complicated thermal problems that could not be solved easily using the methods of the 1950s. In distillation column design, the use of the McCabe-Thiele graphical method for determination of the number of theoretical plates has been replaced by numerical methods that allow consideration of several different components in the feed and product streams.

Barron, R. F.

106

Heat and mass transfer model approach to optimum design of cryogenic air separation plant by packed columns with structured packing  

Microsoft Academic Search

A process simulator for design of a cryogenic air separation plant by packed columns with structured packing was developed by use of our heat and mass transfer model. The heat and mass transfer rates were estimated by correlations which were proposed in our previous work (J. Chem. Eng. Japan 33 (2000) 245). Comparison of the predicted separation performance of a

Nobuaki Egoshi; Hiroshi Kawakami; Koichi Asano

2002-01-01

107

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

SciTech Connect

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

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

1999-04-01

108

Research on the separation properties of empty-column gas chromatography (EC-GC) and conditions for simulated distillation (SIMDIS).  

PubMed

Previous studies have revealed it is possible to separate a high-boiling mixture by gas chromatography in empty fused-silica capillary tubing rather than in columns coated with stationary phase. Chromatographic separation occurs solely on the basis of the different boiling points of the substances separated. The high similarity of such separations to those in classic distillation seems advantageous when gas chromatography is used for simulated distillation. This paper presents results from further research on the separation properties of empty fused silica tubing. The efficiency of this chromatographic system has been examined. The usefulness of such conditions has been studied for simulated distillation, i.e. to determine the boiling-point distribution of complex mixtures, mainly petroleum fractions and products, on the basis of their retention relative to reference substances. The results obtained by use of empty-column gas chromatography (EC-GC) and by use of classical simulated distillation columns have been compared for solutes of different polarity. Studies revealed boiling points determined by EC-GC were more accurate than those obtained by the standard method of simulated distillation. PMID:23925798

Boczkaj, Grzegorz; Kami?ski, Marian

2013-08-08

109

CFD modeling of mass-transfer processes in randomly packed distillation columns  

SciTech Connect

The volume-averaged equations for velocity and concentration fields have been used to simulate the hydrodynamics and mass-transfer processes in randomly packed distillation columns. This approach is regarded as a second-generation computational fluid dynamics (CFD) based model, and a significant departure from the traditional one-dimensional, first-generation models. The model has ability to capture radial and axial variations in flow and mass-transfer conditions. The spatial variation of void fraction has been included to take into account the effect of bed structures. The simulation results have been compared with experimental data reported by Fractionation Research, Inc. (FRI) which performed their tests in a 1.22-m-diameter column with a packed bed height of 3.66 m. For validation, the authors have used data obtained with 15.9-, 25.4-, and 50.8-mm metal Pall rings at various operating conditions. Good agreement between CFD predictions and published experimental data has been obtained. This is regarded as an encouraging sign that CFD models can play a useful role in studying separation processes.

Yin, F.H.; Sun, C.G.; Afacan, A.; Nandakumar, K.; Chuang, K.T.

2000-05-01

110

Analysis of the Transfer Function Model of Tray-Type Binary Distillation Columns with Liquid Hydraulic Delay.  

National Technical Information Service (NTIS)

A transfer function model (TFM) in the frequency domain is used to predict that a distillation column system (compositions to terminal flow rate) is a low pass filter with large time constants and low cut-off frequency. Computed results in frequency and t...

J. B. Edwards B. M. Zhou

1983-01-01

111

Enhanced bioethanol dehydration by extractive and azeotropic distillation in dividing-wall columns  

Microsoft Academic Search

The industrial production of anhydrous bioethanol requires energy demanding distillation steps to overcome the azeotropic behavior of ethanol–water mixture. In spite of the recent developments in pervaporation and adsorption with molecular sieves, the large scale production is dominated by extractive and azeotropic distillation as the separation of choice.This study proposes novel distillation technologies for enhanced bioethanol dehydration, by extending the

Anton A. Kiss; David J-. P. C. Suszwalak

112

Simulation and analysis of extractive distillation process in a valve tray column using the rate based model  

Microsoft Academic Search

Valve trays are becoming popular in the chemical process industries owing to their flexibility to handle a wide range of vapor\\u000a throughputs. Using the rigorous rate based model, the importance of the non-equilibrium approach is demonstrated for a typical\\u000a extractive distillation process in a Glitsch V-1 valve tray column. Simulation results based on an in-house developed code\\u000a indicated that the

Sasmita Pradhan; Aravamudan Kannan

2005-01-01

113

Experiments on water detritiation and cryogenic distillation at TLK; Impact on ITER fuel cycle subsystems interfaces  

SciTech Connect

The ITER Isotope Separation System (ISS) and Water Detritiation System (WDS) should be integrated in order to reduce potential chronic tritium emissions from the ISS. This is achieved by routing the top (protium) product from the ISS to a feed point near the bottom end of the WDS Liquid Phase Catalytic Exchange (LPCE) column. This provides an additional barrier against ISS emissions and should mitigate the memory effects due to process parameter fluctuations in the ISS. To support the research activities needed to characterize the performances of various components for WDS and ISS processes under various working conditions and configurations as needed for ITER design, an experimental facility called TRENTA representative of the ITER WDS and ISS protium separation column, has been commissioned and is in operation at TLK The experimental program on TRENTA facility is conducted to provide the necessary design data related to the relevant ITER operating modes. The operation availability and performances of ISS-WDS have impact on ITER fuel cycle subsystems with consequences on the design integration. The preliminary experimental data on TRENTA facility are presented. (authors)

Cristescu, I.; Cristescu, I. R.; Doerr, L.; Hellriegel, G.; Michling, R. [Forschungszentrum Karlsruhe, Inst. for Technical Physics, Tritium Laboratory Karlsruhe, P.O. Box 3640, D- 76021 Karlsruhe (Germany); Murdoch, D. [EFDA CSU, MPI fuer Plasmaphysik, Garching (Germany); Schaefer, P.; Welte, S.; Wurster, W. [Forschungszentrum Karlsruhe, Inst. for Technical Physics, Tritium Laboratory Karlsruhe, P.O. Box 3640, D- 76021 Karlsruhe (Germany)

2008-07-15

114

COED Transactions, Vol. X, No. 5, May 1978. STAGEF, A Program to Compute the Internal Variables of an Operating Distillation Column.  

ERIC Educational Resources Information Center

|A digital computer program, STAGEF, designed for use with the distillation experiments in a typical undergraduate Chemical Engineering laboratory in Unit Operations is explained. The program enables the student to determine the rate of liquid overflow and vapor boil-up which leaves each tray within the distillation column. The student may also…

Marcovitz, Alan B., Ed.

115

COED Transactions, Vol. X, No. 5, May 1978. STAGEF, A Program to Compute the Internal Variables of an Operating Distillation Column.  

ERIC Educational Resources Information Center

A digital computer program, STAGEF, designed for use with the distillation experiments in a typical undergraduate Chemical Engineering laboratory in Unit Operations is explained. The program enables the student to determine the rate of liquid overflow and vapor boil-up which leaves each tray within the distillation column. The student may also…

Marcovitz, Alan B., Ed.

116

Reactive dividing wall distillation columns: Simulation and implementation in a pilot plant  

Microsoft Academic Search

We performed steady state and dynamic simulations of a reactive Petlyuk column through an equivalent reactive dividing wall column (RDWDC). In the case of the reaction between ethanol and acetic acid catalyzed by sulfuric acid to produce ethyl acetate and water, we have found that the reactive Petlyuk column can achieve set point changes in two control loops of temperature.

Salvador Hernández; Rodrigo Sandoval-Vergara; Fabricio Omar Barroso-Muñoz; Rodolfo Murrieta-Dueñas; Héctor Hernández-Escoto; Juan Gabriel Segovia-Hernández; Vicente Rico-Ramirez

2009-01-01

117

Inconsistencies in dynamic models for ill-conditioned plants: Application to low-order models of distillation columns  

SciTech Connect

The paper addresses the problem of obtaining consistent dynamic models for certain ill-conditioned plants like distillation columns. Due to strong interactions there is often a single dominating slow mode (pole) that results in similar first-order responses for all outputs. Typically, models are identified on the basis of fitting individual responses, but unless special care is taken this will result in an inconsistent overall model with the slow pole repeated. It is shown that such models with excessive slow poles, although a reasonable approximation for open-loop dynamics, yield a poor prediction of the closed-loop behavior of the process, in particular under partial control.

Jacobsen, E.W.; Skogestad, S. (Univ. of Trondheim (Norway). Chemical Engineering)

1994-03-01

118

Simultaneous kinetic resolution of chiral propylene oxide and propylene glycol in a continuous reactive distillation column  

Microsoft Academic Search

Traditionally kinetic resolutions are conducted by batch processing to recover one of the desired enantiomers of the racemate, while the product formed by the resolution is discarded due to its low purity. However, chiral materials are economically valuable and simultaneously conducting the reaction and separation, using reactive distillation, allows for both a reactant enantiomer and a product enantiomer to be

Matthew J. Okasinski; Michael F. Doherty

2003-01-01

119

Equilibrium theory and nonlinear waves for reactive distillation columns and chromatographic reactors  

Microsoft Academic Search

A general framework for analyzing and understanding the dynamics of reactive separation processes is developed. The theory is based on the assumption of simultaneous phase and reaction equilibrium. It makes use of transformed concentration variables, which were first introduced by Doherty and co-workers for the steady state design of reactive distillation processes (Proc. Roy. Soc. London A 413 (1987a) 459).

S. Grüner; A. Kienle

2004-01-01

120

Nonequilibrium cell model for packed distillation columns -- The influence of maldistribution  

SciTech Connect

In this paper the authors present a nonequilibrium model for studying the effects of flow maldistribution in packed columns. The model consists of a set of mass and energy balances along with a set of mass- and energy-transfer correlations. Maldistribution is treated by means of the zone/stage approach, as developed by Zuiderweg et al. Simulations show that, for binary mixtures, packing HETPs are a function of the height of the packing. It should be noted that in some cases the behavior of HETPs is not intuitive, even for binary mixtures. For ternary mixtures, cases were found in which differences in maldistribution patterns can result in substantial differences in column behavior; in some cases completely different column products can be obtained.

Higler, A.; Krishna, R.; Taylor, R.

1999-10-01

121

Development of soft sensor for neural network based control of distillation column.  

PubMed

The present work is aimed at the design of Levenberg-Marquardt (LM) and adaptive linear network (ADALINE) based soft sensors and their application in inferential control of a multicomponent distillation process. Further the ADALINE sensor is trained online using past measurements, to adapt the changes in the inputs and is termed as dynamic ADALINE (D-ADALINE) sensor. The soft sensors are then used in the control loop to obtain LM based inferential controller (LMIC), ADALINE based inferential controller (ADIC) and D-ADALINE based inferential controller (DADIC) for the process. The performance of dynamic controller is also analyzed for different inputs and sampling intervals. The comparison of results shows the efficient and robust prediction capability of D-ADALINE sensor and hence DADIC proves to be the best controller. PMID:23375672

Rani, Asha; Singh, Vijander; Gupta, J R P

2013-01-30

122

Study about sorption in sponge and powder titanium of hydrogen isotopes obtained from a cryogenic distillation process  

Microsoft Academic Search

Currently, hydrogen may be stored as a compressed gas or as cryogenic liquid. Neither method appears to be practical for many applications in which hydrogen use would otherwise be attractive. For example, gaseous storage of stationary fuel is not feasible because of the large volume or weight of the storage vessels. Liquid hydrogen could be used extensively but the liquefaction

F. Vasut; N. Bidica; I. Stefanescu; A. Bornea; A. Preda; M. Zamfirache; C. Ducu

2008-01-01

123

Final Report - Advanced Hydraulic and Mass Transfer Models for Distillation Column Optimization and Design  

SciTech Connect

The project successfully developed a computational fluid dynamics (CFD) based simulation of the hydrodynamics of flow in a commercial structured packing element. This result fulfilled the prime objective of the research program. The simulation utilized commercial CFD code marketed by Fluent Inc. in combination with a novel graphical interface developed by Oak Ridge National Lab. The end product will allow the design of next generation column internals without the need for extensive experimental validation and will expand the fundamental understanding of the vapor-liquid contacting process.

Eldridge, Robert, B.

2005-10-13

124

Design of a selftuning fuzzy control system and the application to a distillation column  

SciTech Connect

A selftuning fuzzy control system was developed for industrial use, with a hierarchical structure of, in the lower loop, an algorithm for feedforward-feedback fuzzy control and, in the upper loop, a learning algorithm for evaluation of the control performance and selftuning of the gain of the feedforward fuzzy control. The function of the selftuning fuzzy controller is to overadjust the gain of the feedback fuzzy controller, using a learning rule which compares the trends in the manipulated variables from the feedforward and feedback controllers. This fuzzy control system was tested in a demethanizer column in an ethylene plant, and was effective for the bottom-temperature control loop, which has, hitherto, been difficult to control.

Hanakuma, Y.; Irizuki, Y; Adachi, M. (Idemitsu Petroleum Co., Ltd., Ichihara (Japan). Technical and Engineering Dept.); Nakanishi, E. (Kobe Univ. (Japan). Dept. of Chemical Engineering)

1994-01-01

125

Simultaneous micro steam distillation\\/solvent extraction for the isolation of semivolatile flavor compounds from cinnamon and their separation by series coupled-column gas chromatography  

Microsoft Academic Search

Simultaneous micro steam distillation\\/solvent extraction is an efficient method of extracting semivolatile flavor and fragrance compounds from cinnamon for subsequent separation by series coupled-column gas chromatography. With pentane as the extraction solvent and an extraction time of 1.5 h clean extracts requiring no further sample preparation prior to gas Chromatographic analysis are obtained. It is shown that adulteration of cinnamon

Arya Jayatilaka; Salwa K. Poole; Colin F. Poole; Tina M. P. Chichila

1995-01-01

126

Distillation for alcohol  

Microsoft Academic Search

A new distillation equipment for alcohol which consists mainly of a brief concentrating column a, a concentrating column b, a compressor C to compress alcohol vapor generated in column B and water evaporator D heated by the compressed alcohol vapor is developed and this especially fits for a distillation source of a glue like solution obtained by alcohol fermentation because

T. Kawase; K. Sawai

1983-01-01

127

Distillative separation of carbon dioxide from light hydrocarbons  

SciTech Connect

In the cryogenic distillative separation of methane from the acid-gas and hydrocarbon components of natural gas, processors generally have difficulty in separating by distillation the carbon dioxide from the light hydrocarbon products (such as ethane) because of the formation of CO/sub 2/-hydrocarbon azeotropes. Koch engineers have discovered that butane is an effective agent for preventing azeotrope formation. Although the presence of butane in the natural gas is not sufficient to prevent this formation, separating butane from the bottoms product and adding it back to the column at the appropriate point aids in the production of separate CO/sub 2/ and ethane streams.

Holmes, A.S.; Ryan, J.M.

1982-09-21

128

Extractive Distillation: A Review  

Microsoft Academic Search

Extractive distillation is more and more commonly applied in industry, and becomes an important separation method in chemical engineering. This paper provides an in?depth review for extractive distillation. Separation sequence of the columns, combination with other separation processes, tray configuration and operation policy are included in process of extractive distillation. Since the solvent plays an important role in the design

Zhigang Lei; Chengyue Li; Biaohua Chen

2003-01-01

129

Free Boundary Problems in Distillation  

Microsoft Academic Search

Design and scaleup of distillation equipment requires an understanding of the vapor-liquid equilibria as well as an understanding of the column hydraulics. This work focuses on two problems of fluid mechanics important in understanding the behavior of distillation columns: the shapes and stability of dielectric drops in an electric field and the flow patterns on distillation trays. Axisymmetric equilibrium shapes

Frederick Karl Wohlhuter

1992-01-01

130

Dealcoholized wines by spinning cone column distillation: phenolic compounds and antioxidant activity measured by the 1,1-diphenyl-2-picrylhydrazyl method.  

PubMed

Spinning cone column (SCC) distillation has been shown to be a commercially suitable technique for dealcoholized wine (DW) manufacturing, but there are not enough studies about its influence on the DW quality. So, the effect of this technique on the antioxidant activity (% of remaining 1,1-diphenyl-2-picrylhydrazyl radical) and the phenolic compound composition of red, rose, and white DW, obtained at pilot plant scale, has been analyzed. Nineteen raw wines (RWs) from different grape varieties and five different Spanish viticultural regions have been studied before and after dealcoholization. The total phenolic content, flavonols, tartaric esters, and anthocyanins, was determined by spectrophotometry, while the content of phenolic compounds such as stilbenes (trans- and cis-resveratrol), flavonols (rutin, quercetin, and myricetin), flavan-3-ols [(+)-catechin and (-)-epicatechin], anthocyanins (malvidin 3-glucoside), and non-flavonoids (gallic, caffeic, and p-coumaric acids) was determined by high-performance liquid chromatography (HPLC). The resveratrol contents in red wines were between 1.81 and 34.01 mg/L in RWs and between 2.12 and 39.57 mg/L in DWs, Merlot being the grape producing the RWs and DWs with higher resveratrol content. In general, the percent of remaining DPPH(*) was similar or slightly higher (until 5 units of % of remaining DPPH(*)) in DWs versus RWs. This small difference may be due to removal of SO2 (that is an antioxidant) from RWs during distillation. DWs and RWs show similar contents of the studied phenolic compounds, with a tendency, in some cases, to exhibit increases after dealcoholization, caused by the concentration effect via removal of the ethanol. From this work, we can deduce that SCC distillation is a dealcoholization technique minimally destructive with the wine phenolic compounds. PMID:19588980

Belisario-Sánchez, Yulissa Y; Taboada-Rodríguez, Amaury; Marín-Iniesta, Fulgencio; López-Gómez, Antonio

2009-08-12

131

THE DISTILLATION OF URANIUM HEXAFLUORIDE AND BROMINE PENTAFLUORIDE IN A 0.5- INCH-DIAMETER PACKED COLUMN  

Microsoft Academic Search

The efficiency of a 0.5 in. dia packed column with 1\\/16 in. nickel ; helices for the separation of the binary system UFâ-- BrFâ was ; investigated. Several distlllations were performed wlth the system ; methylcyclohexane and nheptane for purposes of callbration. For both systems, ; pressure-drop measurements at various flow rates were determined and the flooding ; rates were

Ivins

1962-01-01

132

Synthesis of azeotropic batch distillation separation systems  

Microsoft Academic Search

The sequencing of batch distillation systems, in particular batch distillation columns, can be complicated by the existence of azeotropes in the mixture. These azeotropes can form batch distillation regions where, depending on the initial feed to the batch column, the types of feasible products and separations are limited. It is very important that these distillation regions are known while attempting

Boyd T. Safrit; Arthur W. Westerberg

1997-01-01

133

Cumene by catalytic distillation  

SciTech Connect

Catalytic distillation, a combination of catalytic reaction and distillation in a single column, has several advantages when used in a process to make cumene from benzene and propylene. An extremely high purity cumene is obtained in high yield. The catalytic distillation principle was used in an earlier process to make MTBE. A unit, started up up in Houston refinery in 1981, operated successfully for four years. Since then, three other MTBE units of this design have gone into service.

Shoemaker, J.D.; Jones, E.M. Jr.

1987-06-01

134

Methanol Distillation Optimization  

Microsoft Academic Search

Michigan BioDiesel, LLC of Bangor, Michigan has called for an analysis of their methanol distillation process. The goal of this project was to determine the current operating parameters of the column and suggest improvements to the operation of the column in order to maximize the amount of methanol recovered as product and minimize the amount of waste. It was also

Kristen L. Bellmer; Scott Sherrod

2011-01-01

135

Cryogenic engineering  

NASA Astrophysics Data System (ADS)

Recent developments and trends in cryogenic engineering are reviewed, with emphasis on the role of cryogenics in power generation, machine building, chemistry, and metallurgy. Several cryogenic systems are described, including air-separation apparatus, cryogenic storage systems, cryothermovacuum devices, and the cryogenic systems of superconducting devices. The theoretical principles underlying the design of cryogenic systems are examined, along with the theory for the processes involved.

Beliakov, V. P.

136

Control of a fractional distillation process  

SciTech Connect

In a fractional distillation process in which a heating fluid and waste heat stream are utilized to supply heat to a fractional distillation column and in which the heat supplied from the waste heat stream is not controllable, control of the liquid level in the fractional distillation column is accomplished by manipulating the flow rate of the heating fluid so as to maintain a desired liquid level until such time as the flow rate of the heating fluid becomes zero at which time the flow rate of the external reflux to the fractional distillation column is manipulated to maintain a desired liquid level in the fractional distillation column. A switching of control of the liquid level provides a means by which an uncontrollable heat input may be provided to the fractional distillation column without losing control of the liquid level in the fractional distillation column.

Skraba, F.W.; Tuck, L.

1983-03-22

137

Limit Cycles in Homogeneous Azeotropic Distillation  

Microsoft Academic Search

In spite of significant nonlinearities even in the simplest model, the distillation literature generally takes for granted that distillation columns display relatively simple dynamic behavior. For example, although widely observed in chemical reactors, any instances of periodic oscillations have not yet been associated with models of distillation columns. In this paper we study the steady-state and dynamic behavior of the

Moonyong Lee; Cornelius Dorn; George A. Meski; Manfred Morari

1999-01-01

138

Catalytic distillation extends its reach  

SciTech Connect

Since the early 1980s, catalytic distillation processes have been selected by more than a hundred operators for various applications. Since such a unit performs both reaction and distillation simultaneously, a combined column can replace a separate, fixed-bed reactor and distillation column, thereby eliminating equipment and reducing capital costs. And, compared to the conventional approach, catalytic distillation may also improve other factors, such as reactant conversion, selectivity, mass transfer, operating pressure, oligomer formation and catalyst fouling. The constant washing of the catalyst by liquid flowing down the column and the distillation of high-boiling foulants results in extended catalyst life. Four selective hydrogenation applications of catalytic distillation are discussed: Butadiene selective hydrogenation combined within an MTBE unit; Pentadiene selective hydrogenation; C{sub 4} acetylene conversion; and Benzene saturation.

Rock, K.; McGuirk, T. [Catalytic Distillation Technologies, Houston, TX (United States); Gildert, G.R. [Catalytic Distillation Technologies, Pasadena, TX (United States)

1997-07-01

139

Cryogenics safety  

Microsoft Academic Search

The safety hazards associated with handling cryogenic fluids are discussed in detail. These hazards include pressure buildup when a cryogenic fluid is heated and becomes a gas, potential damage to body tissues due to surface contact, toxic risk from breathing air altered by cryogenic fluids, dangers of air solidification, and hazards of combustible cryogens such as liquified oxygen, hydrogen, or

Reider

1977-01-01

140

Modelling reactive distillation  

Microsoft Academic Search

The design and operation issues for reactive distillation systems are considerably more complex than those involved for either conventional reactors or conventional distillation columns. The introduction of an in situ separation function within the reaction zone leads to complex interactions between vapor–liquid equilibrium, vapor–liquid mass transfer, intra-catalyst diffusion (for heterogeneously catalysed processes) and chemical kinetics. Such interactions have been shown

R. Taylor; R. Krishna

2000-01-01

141

Companded total condensation loxboil air distillation  

Microsoft Academic Search

This patent describes a dual pressure cryogenic distillation process for producing gaseous oxygen from a supply of compressed and cleaned air, comprising: a. cooling a major fraction of the compressed and cleaned air; b. rectifying the major fraction in a high pressure rectifier to liquid nitrogen overhead product and kettle liquid bottom product; c. distilling the kettle liquid in a

1989-01-01

142

Synthesis of separation systems for azeotropic mixtures: Preferred distillation region  

Microsoft Academic Search

An algorithm for automatic generation of sequences of distillation columns and decanters for separation of azeotropic mixtures has been developed where distillation boundaries can be crossed by moving them with pressure change, by exploring curvatures of distillation boundaries or by liquid-liquid splits in decanters. Based on a broad knowledge of distillation regions and distillation boundaries for the separated mixture, open-loop

Stanislaw K. Wasylkiewicz

2006-01-01

143

Complex binary distillation  

SciTech Connect

This procedure extends the McCabe-Thiele diagram to columns having multiple feeds, one or more side-products, one or more points of heat removal or addition, and any combination of these. Although derived for binary systems, the procedure can be adapted for multicomponent distillation.

Kister, H.Z.

1985-01-21

144

Distillation stability using passivity and thermodynamics  

Microsoft Academic Search

Distillation is one of the most important unit operations in the chemical process industry. The stability of distillation systems has always been difficult to determine due to the nonlinear natural of the unit operation. Previous work in the area has had limited success and no theory has been able to show the stability criteria for a general multicomponent distillation column.

Duncan P. Coffey; B. Erik Ydstie; Chad A. Farschman

2000-01-01

145

Pilot plant formaldehyde distillation: experiments and modelling  

Microsoft Academic Search

Despite their industrial importance, only few experimental studies on distillation of aqueous, methanolic formaldehyde solutions are described in the literature. In the present work, for the first time, results from pilot-scale distillation of mixtures of formaldehyde, water, and methanol are presented. The experiments were carried out in a 250mm diameter distillation column equipped with 2m Sulzer BX wire gauze packing.

K. Terelak; S. Trybula; M. Majchrzak; M. Ott; H. Hasse

2005-01-01

146

Chromatographic distillation in petroleum product quality control  

Microsoft Academic Search

The extreme differences in the distillation temperatures of petroleum products are responsible for the existence of several standard methods for determining the distillation curves. In this paper, the feasibility was demonstrated of determining these curves on various petroleum products by chromatographic distillation, using the same procedure and the same apparatus in all cases. Mixtures were separated in a capillary column

G. G. Kholostova; G. S. Shimonaev; M. O. Burova

1988-01-01

147

Molten salt extractive distillation process for zirconium-hafnium separation  

Microsoft Academic Search

This patent describes an improvement in a process for zirconium-hafnium separation. It utilizes an extractive distillation column with a mixture of zirconium and hafnium tetrachlorides introduced into a distillation column having a top and bottom with hafnium enriched overheads taken from the top of the column and a molten salt solvent circulated through the column to provide a liquid phase,

D. F. McLaughlin; R. A. Stoltz

1989-01-01

148

Cryogenic exciter  

SciTech Connect

The disclosed technology is a cryogenic static exciter. The cryogenic static exciter is connected to a synchronous electric machine that has a field winding. The synchronous electric machine is cooled via a refrigerator or cryogen like liquid nitrogen. The static exciter is in communication with the field winding and is operating at ambient temperature. The static exciter receives cooling from a refrigerator or cryogen source, which may also service the synchronous machine, to selected areas of the static exciter and the cooling selectively reduces the operating temperature of the selected areas of the static exciter.

Bray, James William (Niskayuna, NY); Garces, Luis Jose (Niskayuna, NY)

2012-03-13

149

Design of processes with reactive distillation line diagrams  

SciTech Connect

On the basis of the transformation of concentration coordinates, the concept of reactive distillation lines is developed. It is applied to study the feasibility of a reactive distillation with an equilibrium reaction on all trays of a distillation column. The singular points in the distillation line diagrams are characterized in terms of nodes and saddles. Depending on the characterization of the reactive distillation line diagrams, it can be decided whether a column with two feed stages is required. On the basis of the reaction space concept, a procedure for identification of reactive distillation processes is developed, in which the reactive distillation column has to be divided into reactive and nonreactive sections. This can be necessary to overcome the limitations in separation which result from the chemical equilibrium. The concentration profile of this combined reactive/nonreactive distillation column is estimated using combined reactive/nonreactive distillation lines.

Bessling, B. [BASF Ludwigshafen (Germany). Engineering Research and Development; Schembecker, G.; Simmrock, K.H. [Univ. of Dortmund (Germany). Dept. of Chemical Engineering

1997-08-01

150

Separation of azeotropic mixtures by batch distillation using an entrainer  

Microsoft Academic Search

Batch Distillation is an efficient unit operation which allows the separation of a multicomponent mixture into its components in a single column. However, the separation of azeotropic mixtures via distillation is quite complex because at the azeotrope liquid and gas have the same composition and, therefore, the driving force for distillation disappears. A systematical presentation of batch distillation processes for

R. Düssel; J. Stichlmair

1995-01-01

151

A novel structured catalyst packing for catalytic distillation of ETBE  

Microsoft Academic Search

Catalytic distillation can offer significant reduction of capital costs in G\\/L\\/S processes that are equilibrium limited. As an alternative to existing catalytic distillation packings, containing bales or pockets of catalyst stacked in (a section of) the distillation column, a novel structured catalyst packing is proposed. The novel packing consists of a common structured distillation packing, on which a binderless film

O. L. Oudshoorn; M. Janissen; W. E. J. van Kooten; J. C. Jansen; H. van Bekkum; C. M. van den Bleek; H. P. A. Calis

1999-01-01

152

Importance of the selection of feed tray location on the optimum design of a heterogeneous azeotropic distillation column with p-xylene feed impurity  

Microsoft Academic Search

In the production of aromatic acid, such as terephthalic acid, tiny amounts of one reactant (in this study, p-xylene) may also enter into the acetic acid dehydration column through the feed stream. In this work, the process design flowsheets with and without this tiny impurity are both considered. For the case with this tiny impurity in the feed stream, a

I-Lung Chien; Hao-Yeh Lee; Tang-Kai Gau; Hsiao-Ping Huang

2006-01-01

153

Azeotropic distillation  

Microsoft Academic Search

Recent and ongoing research in the distillation of nonideal mixtures is reviewed focusing on advances in the methodologies for the synthesis, design, analysis and control of separation sequences involving homogeneous and heterogeneous azeotropic towers. Maps of residue curves and distillation lines are examined, as well as geometric methods for the synthesis and design of separation sequences, trends in the steady-state

Soemantri Widagdo; Warren D. Seider

1996-01-01

154

Distillation pressure control troubleshooting—The hidden pittfalls of overdesign  

Microsoft Academic Search

The operating pressure of a distillation column is one of the main handles with which to control and optimise separation as it affects most other parameters as well as the overall stability of the column. It is therefore one of the most important parameters to control.Controlling a distillation column, designed to be operated under a vacuum, at the intended operating

Jacques van der Merwe

2011-01-01

155

Digital distillation the easy way  

SciTech Connect

Designing distillation columns may well be the most common problem for chemical engineers. For decades, engineering students have grunted through the iterations of McCabe-Thiele diagrams; working engineers regularly cast a critical eye at column efficiencies and maintenance requirements in their plants. The design and optimization of distillation columns is a problem that has been adapted smoothly to computerization, especially on personal computers. The extensive need for accurate equilibrium and thermodynamics data is tailormade for digital storage. The iterative nature of the design process is also a common element of programming algorithms. Most of the programs on the market feature at least three components: a library of commercially available databases of fluid properties; a distillation or separations engine, using one or several design methods; and algorithms for generating physical-property data synthetically. This paper describes many of the programs on the market for this purpose.

Basta, N.

1995-10-01

156

Solar Distillation  

Microsoft Academic Search

\\u000a “Solar distillation” is a technology for producing potable water from brackish and underground water of low-quality at low\\u000a cost. It can reduce water-scarcity problems together with other water purification technologies. Solar distillation is analogous\\u000a to natural hydrological cycle. It uses an apparatus called a solar still in which water is evaporated using solar energy,\\u000a a form of renewable energy, and

Rahul Dev; Gopal Nath Tiwari

157

Fractional distillation  

Microsoft Academic Search

While practically all the fatty acids produced in the fatty acid industry are distilled products, these materials are all,\\u000a at least to some degree, fractionated fatty acids. Rarely indeed are today’s fatty acids suited for any of the many applications\\u000a to which they are put without the quality and homolog distribution improvements which only fractional distillation can guarantee.\\u000a Thus, this

R. Berger; W. McPherson

1979-01-01

158

Synthesis of azeotropic batch distillation separation systems  

SciTech Connect

The sequencing of batch distillation systems, in particular batch distillation columns, can be complicated by the existence of azeotropes in the mixture. These azeotropes can form batch distillation regions where, depending on the initial feed to the batch column, the types of feasible products and separations are limited. It is very important that these distillation regions are known while attempting to synthesize sequences of batch columns so infeasible designs can be eliminated early on in the design phase. The distillation regions also give information regarding the feasible products that can be obtained when the mixture is separated by using a variety of batch column configurations. The authors will show how a tool for finding the batch distillation regions of a particular mixture can be used in the synthesis of batch distillation column sequences. These sequences are determined by the initial feed composition to the separation network. The network of all possible sequences will be generated by using state-task networks when batch rectifying, stripping, middle vessel, and extractive middle vessel columns are allowed. The authors do not determine which sequence is the best, as the best sequence will depend on the particular application to which one is applying the algorithms. They show an example problem for illustration of this technique.

Safrit, B.T. [Eastman Chemical Co., Kingsport, TN (United States); Westerberg, A.W. [Carnegie Mellon Univ., Pittsburgh, PA (United States)

1997-05-01

159

Azeotropic distillation  

SciTech Connect

Recent and ongoing research in the distillation of nonideal mixtures is reviewed focusing on advances in the methodologies for the synthesis, design, analysis and control of separation sequences involving homogeneous and heterogeneous azeotropic towers. Maps of residue curves and distillation lines are examined, as well as geometric methods for the synthesis and design of separation sequences, trends in the steady-state and dynamic analysis of homogeneous and heterogeneous towers, the nonlinear behavior of these towers, and strategies for their control. Emphasis is placed on the methods of computing all of the azeotropes associated with a multicomponent mixture, on the features that distinguish azeotropic distillations from their zeotropic counterparts, on the potential for steady-state multiplicity, and on the existence of maximum and minimum reflux bounds. Important considerations in the selection of entrainers are examined. For the synthesis of separation trains, when determining the feasible production compositions, the graphical methods are clarified, especially the conditions under which distillation boundaries can be crossed and bounding strategies under finite reflux. The application of geometric theory to locate the fixed points, at minimum reflux, is reviewed in connection with homotopy-continuation algorithms for this purpose. The use of homotopy-continuation algorithms, especially for the steady-state simulation of heterogeneous azeotropic distillations, is justified. Methods for phase stability analysis are reviewed in connection with the location of real bifurcation points at phase transitions, an important feature of algorithms for the dynamic simulation of heterogeneous azeotropic distillations.

Widagdo, S. [Stevens Inst. of Tech., Hoboken, NJ (United States); Seider, W.D. [Univ. of Pennsylvania, Philadelphia, PA (United States). Dept. of Chemical Engineering

1996-01-01

160

Distillation (1980-1990): A bibliography  

SciTech Connect

Distillation is one of the fundamental unit operations of chemical engineering. Over the past 50 years a significant proportion of the published literature has been concerned with distillation fundamentals and applications. This article is a bibliography of 451 published papers on selected distillation topics for the period 1980-1990. The topics covered are: theory and principles; calculations and design methods; efficiency; column design data; and control and instrumentation.

Ray, M.S. (Curtin Univ. of Technology, Perth (Australia))

1992-01-01

161

Column internals  

SciTech Connect

In the fields of distillation, absorption, stripping and extraction, theory and technology go hand in hand. The thermodynamic principles of phase equilibrium and the concepts of mass transfer and fluid flow are of primary importance in all of these operations. The engineer must understand these phenomena to select equipment effectively. This article discusses the latest in commercial technology in column internals for gas-liquid and liquid-liquid contacting. The principles of operation are explained vis-a-vis the characteristics of the applications in which they are used. The focus is on moderate-to-large columns for refining and chemical applications. Guidelines for selecting the most appropriate type of device are presented, and examples of typical applications are described.

Bravo, J.L. [Shell Oil Co., Houston, TX (United States)

1998-02-01

162

Distillation plus membrane processing of gas streams  

SciTech Connect

This patent describes a process for separating components of a feed gas stream comprising carbon dioxide, hydrogen sulfide, nitrogen, methane, and higher molecular weight hydrocarbons to form a carbon dioxide-rich stream and a methane-rich stream. It comprises: passing the feed gas stream to a first fractional distillation column; withdrawing a first overhead stream from the first fractional distillation column; withdrawing a first bottoms stream from the first fractional distillation column; passing the first overhead stream to a second fractional distillation column; withdrawing a second overhead stream wherein the second overhead stream is withdrawn from the second fractional distillation column; withdrawing a second bottoms stream wherein the second bottoms stream is withdrawn from the second fractional distillation column; passing the second overhead stream to a membrane separation unit; withdrawing a residual gas stream from the membrane separation unit to form the methane-rich stream; and withdrawing a residual gas stream from the membrane separation unit to form a recycle stream having a substantially increased concentration of carbon dioxide relative to the concentration of carbon dioxide in the second overhead stream.

Waldo, R.A.; Burkinshaw, J.R.

1990-06-26

163

Distillation pressure control  

SciTech Connect

This patent describes an apparatus comprising: a fractional distillation column; means for providing a feed mixture to be fractionated to the column; means for withdrawing an overhead vapor stream from the column; means for condensing at least a portion of the overhead vapor stream; an accumulator; means for passing the resulting at least partially condensed overhead stream into the accumulator; means for withdrawing condensate from the accumulator and for passing a first portion of the thus withdrawn condensate into an upper portion of the column as an external reflux therefore and for passing a second portion of the thus withdrawn condensate as an overhead liquid product stream; means for withdrawing a first vapor stream from the accumulator and for passing a first portion of the thus withdrawn vapor through a first control valve to a vapor recovery unit and for passing a second portion of the thus withdrawn vapor stream through a second control valve to a waste gas disposal unit; means for providing a second vapor stream from an external source to the column through a third control valve wherein the second vapor stream is compatible with the first vapor stream.

Hofferber, J.A.

1988-09-06

164

Process for Efficient Fermentation and Distillation for Alcohol. Final Report, 12 August 1981-15 June 1982.  

National Technical Information Service (NTIS)

The feasibility of a vapor-compression distillation column in conjunction with continuous fermentation is studied. The distillation process was studied and a small scale distillation model was constructed and tested. (ERA citation 08:007092)

C. M. DeLair

1981-01-01

165

Process for efficient fermentation and distillation for alcohol. Final report, 12 August 1981-15 June 1982  

Microsoft Academic Search

The feasibility of a vapor-compression distillation column in conjunction with continuous fermentation is studied. The distillation process was studied and a small scale distillation model was constructed and tested. (MHR)

DeLair

1981-01-01

166

Process for efficient fermentation and distillation for alcohol. Final report, 12 August 1981-15 June 1982  

SciTech Connect

The feasibility of a vapor-compression distillation column in conjunction with continuous fermentation is studied. The distillation process was studied and a small scale distillation model was constructed and tested. (MHR)

DeLair, C.M.

1981-06-01

167

Membrane distillation  

Microsoft Academic Search

This paper provides a state-of-the-art review of the separation process known as membrane distillation, MD. An introduction to the terminology and fundamental concepts associated with MD as well as a historical review of the developments in MD are presented. Membrane properties, transport phenomena, and module design are discussed in detail. A critical evaluation of the MD literature is incorporated throughout

Kevin W. Lawson; Douglas R. Lloyd

1997-01-01

168

Multiple steady states of distillation and its realisation  

Microsoft Academic Search

Multiplicity of steady states is known for distillation of mixtures with certain type of distillation line map. This paper presents the study of its realisation for the ternary mixture with one binary azeotrope formed between light and heavy component. Continuous single-feed distillation column with a finite number of trays is considered. The steady states are determined by simulation of the

Valeri N. Kiva; Bella M. Alukhanova

1997-01-01

169

Molten salt extractive distillation process for zirconium-hafnium separation  

SciTech Connect

This patent describes an improvement in a process for zirconium-hafnium separation. It utilizes an extractive distillation column with a mixture of zirconium and hafnium tetrachlorides introduced into a distillation column having a top and bottom with hafnium enriched overheads taken from the top of the column and a molten salt solvent circulated through the column to provide a liquid phase, and with molten salt solvent containing zirconium chloride being taken from the bottom of the distillation column. The improvements comprising: utilizing a molten salt solvent consisting principally of lithium chloride and at least one of sodium, potassium, magnesium and calcium chlorides; stripping of the zirconium chloride taken from the bottom of the distillation column by electrochemically reducing zirconium from the molten salt solvent; and utilizing a pressurized reflux condenser on the top of the column to add the hafnium chloride enriched overheads to the molten salt solvent previously stripped of zirconium chloride.

McLaughlin, D.F.; Stoltz, R.A.

1989-10-17

170

Exergy simulation and optimization of adiabatic and diabatic binary distillation  

Microsoft Academic Search

A detailed exergy analysis of a distillation system has been conducted. This analysis is divided in four parts: (1) adiabatic rectification column; (2) adiabatic stripping column; (3) diabatic rectification column; and (4) diabatic stripping column. The results of all cases are presented in this paper. This analysis concerns the mixture water–ethanol working at 1 bar. The main objective is to

Ricardo Rivero

2001-01-01

171

Dephlegmator process for carbon dioxide-hydrocarbon distillation  

SciTech Connect

This patent describes a process for the separation of a carbonaceous off-gas stream containing a quantity of acid gases, such as carbon dioxide, hydrogen sulfide and carbonyl sulfide, wherein the off-gas stream is compressed, cooled and separated in a low temperature distillation column into a fuel gas stream which is recovered from the top portion of the distillation column, a liquefied acid gas sidestream and a bottoms liquid stream. The improvement comprises: (a) incorporating a dephlegmator as the top portion of the distillation column; (b) passing at least a portion of the liquefied acid gas sidestream to the dephlegmator for indirect heat exchange with distillation column fluids thereby providing refrigeration for the dephlegmator; and (c) subcooling at least a portion of the bottoms liquids stream and passing the subcooled bottoms liquids stream to the dephlegmator for indirect heat exchange with distillation column fluids thereby providing refrigeration for the dephlegmator.

Lucadamo, G.A.; Rowles, H.C.

1988-01-19

172

Hydrothermal carbonization of distiller’s grains  

Microsoft Academic Search

Wet distiller’s grains are intermediate byproducts of ethanol manufacture that have high moisture contents and require significant energy for drying and conversion into dry distiller’s grains. Hydrothermal carbonization was investigated as a wet process to provide alternative products, and chars were obtained in moderate yield that possessed high heats of combustion. The mechanism of char formation was also investigated employing

Steven M. Heilmann; Lindsey R. Jader; Michael J. Sadowsky; Frederick J. Schendel; Marc G. von Keitz; Kenneth J. Valentas

2011-01-01

173

Reactive separation of isobutene from C4 crack fractions by catalytic distillation processes  

Microsoft Academic Search

Reactive distillation is a hybrid process where chemical reaction and distillative separation are performed in a single equipment. Even though reactive distillation could increase the selectivity of the desired product by the selective reaction this is not always true as shown in this work. A study on the MTBE reaction system using two coupled reactive distillation columns to separate a

Zhiwen Qi; Kai Sundmacher; Erik Stein; Achim Kienle; Aspi Kolah

2002-01-01

174

Silicon Isotope Separation by Distillation of Silicon Tetrafluoride  

Microsoft Academic Search

Silicon isotopes were separated by distilling silicon tetrafluoride in a 150-cm packed column at temperatures of 189–206 K. The data show a reverse isotope effect with heavy isotopes more volatile in this temperature range. At total reflux, the maximum column separations were 0.926 for \\/Si and 0.872 for Si\\/Si. Carbon monoxide was also distilled in the column to obtain an

Thomas R. Mills

1990-01-01

175

CRYOGENIC DEWAR  

DOEpatents

This patent relates to a dewar for storing cryogenic gase and is of the type having aii inner flask surrounded by a vacuum jacket and having a vent spout through which evaporating gas escapes. Heretofore substantial gas loss has resulted from the radiation of heat towards the flask from the warmer outer elements of the dewar. In this invention, the mask is surrounded by a thermally conducting shield which is disposed in the vacuum space between the flask and the outer elements of the dewar. The shield contacts only the vent spout, which is cooled by the evaporating gas, and thus is maintained at a temperature very close to that of the flask itself. Accordingly, heat radiated toward the flask is intercepted and conducted to the evaporating gas rather than being re-radiated towards the hask. In a liquid helium dewar of typical configniration the mention reduces the boil-off rate by approximately one-half.(AEC)

Chamberlain, W.H.; Maseck, H.E.

1964-01-28

176

Distillation sequence for the purification and recovery of hydrocarbons  

SciTech Connect

This invention is an improved distillation sequence for the separation and purification of ethylene from a cracked gas. A hydrocarbon feed enters a C2 distributor column. The top of the C2 distributor column is thermally coupled to an ethylene distributor column, and the bottoms liquid of a C2 distributor column feeds a deethanizer column. The C2 distributor column utilizes a conventional reboiler. The top of the ethylene distributor is thermally coupled with a demethanizer column, and the bottoms liquid of the ethylene distributor feeds a C2 splitter column. The ethylene distributor column utilizes a conventional reboiler. The deethanizer and C2 splitter columns are also thermally coupled and operated at a substantially lower pressure than the C2 distributor column, the ethylene distributor column, and the demethanizer column. Alternatively, a hydrocarbon feed enters a deethanizer column. The top of the deethanizer is thermally coupled to an ethylene distributor column, and the ethylene distributor column utilizes a conventional reboiler. The top of the ethylene distributor column is thermally coupled with a demethanizer column, and the bottoms liquid of the ethylene distributor column feeds a C2 splitter column. The C2 splitter column operates at a pressure substantially lower than the ethylene distributor column, the demethanizer column, and the deethanizer column.

Reyneke, Rian (Katy, TX); Foral, Michael (Aurora, IL); Papadopoulos, Christos G. (Naperville, IL); Logsdon, Jeffrey S. (Naperville, IL); Eng, Wayne W. Y. (League City, TX); Lee, Guang-Chung (Houston, TX); Sinclair, Ian (Warrington, GB)

2007-12-25

177

Experimental study of multiple steady states in homogeneous azeotropic distillation  

Microsoft Academic Search

Bekiaris et al. (1993) explained the existence of multiple steady states in homogeneous ternary azeotropic distillation, on the basis of the analysis of the case of infinite reflux and infinite column length (infinite number of trays). They showed that the predictions of multiple steady states for such infinite columns have relevant implications for columns of finite length operated at finite

T. E. Guettinger; Cornelius Dorn; Manfred Morari

1997-01-01

178

Solar distillation of fuel alcohol. Final report  

SciTech Connect

The objective of this project was to demonstrate the application of solar energy to the distillation of ethanol for use as a fuel or fuel additive. An experimental facility was constructed to study the distillation of ethanol from a low concentration in water (10 to 20%) to a high concentration (>90%) using solar energy as the only heat source. Concentrating solar collectors were used to supply energy to a thermocline storage tank which provided a near constant temperature energy source to drive a laboratory scale distillation column. Various tests were performed on each component of the system to study its behavior. The data gathered during these tests were compared to predicted performance from theoretical considerations. Close agreement between theory and experiment was obtained in all cases. In the laboratory, energy was supplied at slightly above 210/sup 0/F to a column of 20 actual trays and a still concentration of 10% ethanol to yield a 90% ethanol distillate. Obviously, solar energy can successfully be utilized for the distillation of fuel alcohol. In an example scenario, 7500 Btu per pound of distillate are found to be needed to produce 90% ethanol. If combusted, this distillate would yield 1.7 times the energy used to produce it.

Green, S.T.; Deffenbaugh, D.M.

1981-08-31

179

Solving gas processing problems. Part 7. Distillation programs ease calculations  

SciTech Connect

Short cut distillation and tray-by-tray programs make a valuable addition to the minicomputer library for anyone involved in the processing of natural gas and/or natural gas liquids. There are two distillation packages available. The first is the shortcut distillation program which uses minimum trays and minimum reflux calculations to provide estimates of the values of operating reflux and plates required in a multicomponent distillation. The second is a tray-by-tray calculation which provides rigorous heat and material balances in combination with equilibrium calculations to estimate performance of multicomponent distillation columns.

Maddox, R.N.; Erbar, J.H.

1981-06-15

180

Refrigeration for Cryogenic Sensors.  

National Technical Information Service (NTIS)

Research in cryogenically cooled refrigerators is discussed. Low-power Stirling cryocoolers; spacecraft-borne long-life units; heat exchangers; performance tests; split-stirling, linear-resonant, cryogenic refrigerators; and computer models are among the ...

M. G. Gasser

1983-01-01

181

Refrigeration for Cryogenic Sensors  

SciTech Connect

Research in cryogenically cooled refrigerators is discussed. Low-power Stirling cryocoolers; spacecraft-borne long-life units; heat exchangers; performance tests split-stirling, linear-resonant, cryogenic refrigerators; and computer models are among the topics discussed.

Gasser, M.G.

1983-12-01

182

Cryogenic properties of polymers  

Microsoft Academic Search

The cryogenic properties of polymers are recently drawing attention with new developments in space, superconducting magnet and electronic technologies. Requirements for polymeric materials used in cryogenic environments are extremely severe and complicated. Research aimed at meeting these requirements is focused in two directions: one concerns the physical properties of polymers at cryogenic temperatures, while the other is concerned with the

Okimichi Yano; Hitoshi Yamaoka

1995-01-01

183

Setting the Pressure at Which to Conduct a Distillation.  

ERIC Educational Resources Information Center

|Discusses how pressure setting is determined for distillation columns, examining factors which must be considered when optimizing design for economical balance. Also discusses the basics of heat exchangers and cites a common problem with pressure differences. (JM)|

Barduhn, Allen J.

1984-01-01

184

Feasibility of separations for distillation of nonideal ternary mixtures  

Microsoft Academic Search

The product compositions in single-feed distillation columns can be specified only in certain regions of the composition space, which depend only on the pressure, feed, and vapor-liquid equilibrium for the mixture. In nonideal mixtures, even without azeotropes, the regions may allow unusual product distributions. For example, the distillate in a direct split is composed primarily of the lightest component. Intuition

Z. T. Fidkowski; M. F. Doherty; M. F. Malone

1993-01-01

185

Distillation with Vapour Compression. An Undergraduate Experimental Facility.  

ERIC Educational Resources Information Center

Discusses the need to design distillation columns that are more energy efficient. Describes a "design and build" project completed by two college students aimed at demonstrating the principles of vapour compression distillation in a more energy efficient way. General design specifications are given, along with suggestions for teaching and…

Pritchard, Colin

1986-01-01

186

Distillation with Vapour Compression. An Undergraduate Experimental Facility.  

ERIC Educational Resources Information Center

|Discusses the need to design distillation columns that are more energy efficient. Describes a "design and build" project completed by two college students aimed at demonstrating the principles of vapour compression distillation in a more energy efficient way. General design specifications are given, along with suggestions for teaching and…

Pritchard, Colin

1986-01-01

187

Dynamic catalytic distillation: Advanced simulation and experimental validation  

Microsoft Academic Search

Reactive distillation offers a number of potential advantages, so that many traditional operations are currently being investigated in order to discover further applications of this technology. Increasingly, it is performed in columns with catalytic packings that combine the advantages of normal structured packings and heterogeneous catalysts. Analysis of reactive distillation is difficult due to strong physico-chemical interactions, and it is

L. U. Kreul; A. Górak; C. Dittrich; P. I. Barton

1998-01-01

188

A singularity theory approach to the study of reactive distillation  

Microsoft Academic Search

Simulation studies suggest that reactive distillation processes exhibit complex multiple steady state behavior in many cases, while sources for these multiplicities have not yet been identified adequately. A singularity theory approach is applied to one-stage reactive distillation columns to contribute to the identification of possible sources of steady state multiplicities especially those related to different chemical reactions. A proposed computational

V. Gehrke; W. Marquardt

1997-01-01

189

Multiplicity Analysis in Reactive Distillation Column Using ASPEN PLUS 1 1 Supported by the Key Project of National Natural Science Foundation of China (No.20436040) and the National Natural Science Foundation of China (No.20176044, No.20476084)  

Microsoft Academic Search

Reactive distillation processes for synthesis of ethylene glycol (EG) and ethyl tert-butyl ether (ETBE) were modeled with the simulation package ASPEN PLUS. The input multiplicity and output multiplicity were discussed with the method of sensitivity analysis for both cases. In EG production process, steady state multiplicities were studied in terms of effective liquid holdup volume and boil-up ratio. In ETBE

Bolun YANG; Jiang WU; Guosheng ZHAO; Huajun WANG; Shiqing LU

2006-01-01

190

Hybrid nonlocality distillation  

NASA Astrophysics Data System (ADS)

In this Letter, we introduce the notion of hybrid nonlocality distillation, in which different nonlocal boxes are exploited for nonlocality distillation. Here, we quantify the nonlocality using the violation degree of either the Clauser-Horne-Shimony-Holt inequality or the I3322 inequality. Our study shows that hybrid nonlocality distillation can outperform nonlocality distillation using copies of single nonlocal boxes. In particular, more nonlocality of undistillable boxes can be activated with the assistance of distillable boxes. Equivalently, distillable boxes can achieve more nonlocality with the assistance of undistillable boxes.

Wu, Keng-Shuo; Hsu, Li-Yi

2013-08-01

191

Nonequilibrium modeling of three-phase distillation  

Microsoft Academic Search

A nonequilibrium (NEQ) model for a complete three-phase distillation in tray columns is described. The model consists of a set of mass and energy balances for each of the three possible phases present. Mass and heat transfer between these phases is modeled using the Maxwell–Stefan equations. Equilibrium is only assumed at the phase boundary between two phases. The equilibrium stage

A. Higler; R. Chande; R. Taylor; R. Baur; R. Krishna

2004-01-01

192

Control of a fractional distillation process  

SciTech Connect

This patent describes a method for preventing the actual pressure in a fractional distillation column from exceeding a high limit for the pressure in the fractional distillation column. This method consists of the steps of: establishing a first signal representative of the flow rate of the external reflux required to maintain a process variable at a desired value for a process variable; establishing a second signal representative of the actual pressure in the fractional distillation column means; establishing a third signal representative of a high limit for the pressure in the fractional distillation column means; comparing the second signal and the third signal and establishing a pressure compensating signal which is responsive to the difference between the second signal and the third signal. The pressure compensating signal has a magnitude of zero if the magnitude of the second signal is not greater than the magnitude of the third signal and has a first magnitude with the dimension of flow rate if the second signal is greater than the third signal; combining the first signal and the pressure compensating signal to establish a control signal; and manipulating the flow rate of the external reflux in response to the control signal. The first magnitude of the pressure compensating signal is such that combining the first signal and the pressure compensating signal results in a reduction in the flow rate of the external reflux required by the first signal if the actual pressure in the fractional distillation column means is greater than the high limit represented by the third signal.

Albers, L.R.

1986-03-25

193

Few-Step Iterative Methods for Distillation Process Design Using the Trajectory Bundle Theory: Algorithm Structure  

Microsoft Academic Search

A new method is suggested for distillation design. The method is based on a theory that predicts the arrangement of distillation trajectory bundles in the concentration simplex. At a preset excess reflux factor, it enables one to determine the possible compositions in the feed cross section and to construct, tray-by-tray, the distillation trajectories for column sections, proceeding from the feed

F. B. Petlyuk; R. Yu. Danilov

2001-01-01

194

Recovery of aromatics from pyrolysis gasoline by conventional and energy-integrated extractive distillation  

Microsoft Academic Search

Extractive distillation is widely used technology for recovering aromatics from different feedstock. This study investigates the recovery of aromatics which has an important commercial application such as benzene, toluene and xylenes from pyrolysis gasoline using a solvent called N-methylpyrolidone. The study also examines the procedures involved in implementing the energy-integrated extractive distillation technologies such as Petlyuk column, divided wall column

Faten Abushwireb; Hadi Elakrami; Mansour Emtir

2007-01-01

195

Multiple steady states in binary distillation—Theoretical and experimental results  

Microsoft Academic Search

Steady-state multiplicity and instability in distillation is studied theoretically and experimentally for columns with volumetric reflux. Using nonlinear wave propagation theory for distillation processes, we derive simple expressions for the prediction of multiplicity regions in parameter space with paper and pencil. This method also gives further insight into qualitative column dynamics in the region of multiple steady states. The results

A. Kienle; M. Groebel; E. D. Gilles

1995-01-01

196

Kinetic Method for Hydrogen-Deuterium-Tritium Mixture Distillation Simulation  

SciTech Connect

Simulation of hydrogen distillation plants requires mathematical procedures suitable for multicomponent systems. In most of the present-day simulation methods a distillation column is assumed to be composed of theoretical stages, or plates. However, in the case of a multicomponent mixture theoretical plate does not exist.An alternative kinetic method of simulation is depicted in the work. According to this method a system of mass-transfer differential equations is solved numerically. Mass-transfer coefficients are estimated with using experimental results and empirical equations.Developed method allows calculating the steady state of a distillation column as well as its any non-steady state when initial conditions are given. The results for steady states are compared with ones obtained via Thiele-Geddes theoretical stage technique and the necessity of using kinetic method is demonstrated. Examples of a column startup period and periodic distillation simulations are shown as well.

Sazonov, A.B.; Kagramanov, Z.G.; Magomedbekov, E.P. [Mendeleyev University of Chemical Technology of Russia (Russian Federation)

2005-07-15

197

Maximum fractionation by distillation of systems with constant relative volatilities  

Microsoft Academic Search

This paper addresses the problem of shortcut simulation of a continuous distillation column. A computationally inexpensive approach is presented which considers the separation of a given feed in a column with an infinite number of stages in both the enriching and the stripping sections. The results so obtained represent the maximum fractionation that can be achieved for the given mixture

Massimiliano Barolo; G. Berto Guarise

1994-01-01

198

Simulation of 1,3Butadiene Production Process by Dimethylfomamide Extractive Distillation  

Microsoft Academic Search

Nowadays, extractive distillation is the main technique to produce 1,3-butadiene. This study simulatedthe 1,3-butadiene production process with DMF extractive distillation by Aspen Plus. The solvent ratio is the most important parameter to the extractive distillation process. The article has given out the proper solvent ratios, refluxratios, distillate ratios, and bottom product ratios of the columns. It also discusses the thermal

Xiaojian YANG; Xuan YIN; Pingkai OUYANG

2009-01-01

199

Distillation of liquid fuels by thermogravimetry  

SciTech Connect

The most widely used separation technique in the petroleum industry and other liquid fuel production processes as well as in much of the chemical industry is distillation. To design and operate an appropriate commercial and laboratory distillation unit requires a knowledge of the boiling point distribution of the materials to be separated. In recognition of these needs, the ASTM developed the distillation procedures of D86, D216, D447, D850, and D1078. They are widely used in laboratories for the purposes of sample characterization, product and quality control, and distillation column design. However, the significant drawbacks of these ASTM methods include (1) close monitoring of the distillation is required. This is particularly difficult for those samples which are very toxic and/or cause any other safety problems; (2) the sample under test must be transparent and free of separated water; and (3) results obtained by these methods are not particularly precise. This motivated the development of a novel automatic distillation system based on the use of a custom-built thermogravimetric apparatus.

Huang, He; Wang, Keyu; Wang, Shaojie [Univ. of Delaware, Newark, DE (United States)] [and others

1996-12-31

200

Supercritical fluid chromatography hyphenated with twin comprehensive two-dimensional gas chromatography for ultimate analysis of middle distillates.  

PubMed

This paper reports the conditions of online hyphenation of supercritical fluid chromatography (SFC) with twin comprehensive two-dimensional gas chromatography (twin-GCxGC) for detailed characterization of middle distillates; this is essential for a better understanding of reactions involved in refining processes. In this configuration, saturated and unsaturated compounds that have been fractionated by SFC are transferred on two different GC x GC columns sets (twin-GCxGC) placed in the same GC oven. Cryogenic focusing is used for transfer of fractions into the first dimension columns before simultaneous GCxGC analysis of both saturated and unsaturated fractions. The benefits of SFC-twin-GC x GC are demonstrated for the extended alkane, iso-alkane, alkene, naphthenes and aromatics analysis (so-called PIONA analysis) of diesel samples which can be achieved in one single injection. For that purpose, saturated and unsaturated compounds have been separated by SFC using a silver loaded silica column prior to GC x GC analysis. Alkenes and naphthenes are quantitatively recovered in the unsaturated and saturated fractions, respectively, allowing their identification in various diesel samples. Thus, resolution between each class of compounds is significantly improved compared to a single GCxGC run, and for the first time, an extended PIONA analysis of diesel samples is presented. PMID:20053407

Adam, Frédérick; Thiébaut, Didier; Bertoncini, Fabrice; Courtiade, Marion; Hennion, Marie-Claire

2009-12-28

201

Cryogenic Material Properties Database Cryogenic Material Properties Database Cryogenic Material Properties Database Cryogenic Material Properties Database  

Microsoft Academic Search

NIST has published at least two references compiling cryogenic material properties. These include the Handbook on Materials for Superconducting Machinery and the LNG Materials & Fluids. Neither has been updated since 1977 and are currently out of print. While there is a great deal of published data on cryogenic material properties, it is often difficult to find and not in

E. D. Marquardt; Ray Radebaugh

202

Flexible cryogenic conduit  

Microsoft Academic Search

A flexible and relatively low cost cryogenic conduit is described. The flexible cryogenic conduit of the present invention comprises a first inner corrugated tube with single braided serving, a second outer corrugated tube with single braided serving concentric with the inner corrugated tube, and arranged outwardly about the periphery of the inner corrugated tube and between the inner and outer

P. D. Brindza; R. R. Wines; J. J. Takacs

1999-01-01

203

Cryogenic Gravity Meter.  

National Technical Information Service (NTIS)

The report describes the progress made towards the design and fabrication of a cryogenic gravity meter intended to have a sensitivity of about 25 millimicrogal. The cryogenic gravity meter consists of two parts--a suspension unit and a detection module. T...

V. S. Tuman

1970-01-01

204

Cryogenic Gravity Meter.  

National Technical Information Service (NTIS)

The report describes the progress made towards the design and fabrication of a cryogenic gravity meter intended to have a sensitivity of about 25 millimicrogal. The cryogenic gravity meter consists of two parts--a suspension unit and a detection module. T...

A. Waleh V. S. Tuman

1972-01-01

205

Cryogenic thermal diodes  

Microsoft Academic Search

Space based cryogenic thermal management systems for advanced infrared sensor platforms are a critical failure mode to the spacecraft missions they are supporting. Recent advances in cryocooler technologies have increased the achievable cooling capacities and decreased the operating temperatures of these systems, but there is still a fundamental need for redundancy in these systems. Cryogenic thermal diodes act as thermal

Brandon R. Paulsen; J. C. Batty; John Agren

2000-01-01

206

Multipartite nonlocality distillation  

SciTech Connect

The stronger nonlocality than that allowed in quantum theory can provide an advantage in information processing and computation. Since quantum entanglement is distillable, can nonlocality be distilled in the nonsignalling condition? The answer is positive in the bipartite case. In this article the distillability of the multipartite nonlocality is investigated. We propose a distillation protocol solely exploiting xor operations on output bits. The probability-distribution vectors and matrix are introduced to tackle the correlators. It is shown that only the correlators with extreme values can survive the distillation process. As the main result, the amplified nonlocality cannot maximally violate any Bell-type inequality. Accordingly, a distillability criterion in the postquantum region is proposed.

Hsu, Li-Yi; Wu, Keng-Shuo [Department of Physics, Chung Yuan Christian University, Chungli 32023, Taiwan (China)

2010-11-15

207

Multipartite nonlocality distillation  

NASA Astrophysics Data System (ADS)

The stronger nonlocality than that allowed in quantum theory can provide an advantage in information processing and computation. Since quantum entanglement is distillable, can nonlocality be distilled in the nonsignalling condition? The answer is positive in the bipartite case. In this article the distillability of the multipartite nonlocality is investigated. We propose a distillation protocol solely exploiting xor operations on output bits. The probability-distribution vectors and matrix are introduced to tackle the correlators. It is shown that only the correlators with extreme values can survive the distillation process. As the main result, the amplified nonlocality cannot maximally violate any Bell-type inequality. Accordingly, a distillability criterion in the postquantum region is proposed.

Hsu, Li-Yi; Wu, Keng-Shuo

2010-11-01

208

Free Boundary Problems in Distillation.  

NASA Astrophysics Data System (ADS)

Design and scaleup of distillation equipment requires an understanding of the vapor-liquid equilibria as well as an understanding of the column hydraulics. This work focuses on two problems of fluid mechanics important in understanding the behavior of distillation columns: the shapes and stability of dielectric drops in an electric field and the flow patterns on distillation trays. Axisymmetric equilibrium shapes and stability of dielectric drops subject to an applied electric field are determined by solving simultaneously the Young-Laplace equation for drop shape and the Maxwell equations for field distribution. Both linearly and nonlinearly polarizable drops are studied, as are drops that are pendant/sessile on a supporting plate and those that are floating freely between two plates. The range of parameters for which hysteresis in drop deformation can be observed is given for linearly and nonlinearly polarizable drops. Properly accounting for the effects of nonlinear polarization brings the theoretical results of this work into accord with previously published experimental results. Detailed examination of the electric fields inside nonlinearly polarizable drops reveals that they are very nonuniform, in contrast to the nearly uniform fields usually found in linearly polarizable drops. The concept of depth averaging the equations of motion for a thin film (relative to the length of the distillation tray) is used to reduce the three-dimensional, free surface flow problem to two dimensions. A one-dimensional model is first used to gain understanding into the behavior of the bulk flow, ignoring any edge effects. A rise in the height profile on the tray, or hydraulic jump, is predicted. The effects of Reynolds number, capillary number (surface tension), tray geometry, and film thickness are all examined. The importance of the downcomers is shown. The two-dimensional model allows examination not only of rectangular trays, but also round trays and trays which are annular arcs, so called "race track" trays. A large zone of recirculation is predicted near the walls of round trays. This is confirmed in published experimental results and in experimental observations reported here. Race track trays did not show recirculation even at large arc angles.

Wohlhuter, Frederick Karl

209

Contact structure for use in catalytic distillation  

DOEpatents

A method and apparatus are disclosed for conducting catalytic chemical reactions and fractionation of the reaction mixture, comprising and feeding reactants into a distillation column reactor contracting said reactant in a liquid phase with a fixed bed catalyst in the form of a contact catalyst structure, consisting of closed porous containers containing the catalyst for the reaction and a clip means to hold and support said containers, which are disposed above, i.e., on the distillation trays in the tower. The trays have weir means to provide a liquid level on the trays to substantially cover the containers. In other words, the trays function in their ordinary manner with the addition thereto of the catalyst. The reaction mixture is concurrently fractionated in the column. 7 figs.

Jones, E.M. Jr.

1985-08-20

210

Contact structure for use in catalytic distillation  

DOEpatents

A method is described for conducting catalytic chemical reactions and fractionation of the reaction mixture comprising feeding reactants into a distillation column reactor, contracting said reactant in liquid phase with a fixed bed catalyst in the form of a contact catalyst structure consisting of closed porous containers containing the catalyst for the reaction and a clip means to hold and support said containers, which are disposed above, i.e., on the distillation trays in the tower. The trays have weir means to provide a liquid level on the trays to substantially cover the containers. In other words, the trays function in their ordinary manner with the addition thereto of the catalyst. The reaction mixture is concurrently fractionated in the column. 7 figs.

Jones, E.M. Jr.

1984-03-27

211

Telescoping Columns.  

National Technical Information Service (NTIS)

A power operated telescoping column is described for the deployment and retraction of a large parabolic antenna for space applications. The column consists of several axially elongated rigid structural sections nested within one another. The outermost and...

J. T. Mazur

1978-01-01

212

Winogradsky Columns  

NSDL National Science Digital Library

This is an exercise about Winogradsky Columns with emphasis placed on the formation and properties of microbial biofilms. It includes background reference material, a field/lab exercise, and several applications. Applications include methods for sampling column layers and a description of how to measure the electro-chemical gradient that develops within the column. Scientific illustrations and images are included as visual references.

Lennox, John; State, Penn

213

Energy efficient distillation apparatus  

Microsoft Academic Search

An energy efficient distillation method is provided which is particularly adapted for use on a dairy farm, and which comprises a distilland evaporating receptacle, a distillate condensing receptacle, and a conduit interconnecting the evaporating receptacle and the condensing receptacle. A vacuum pump is provided for drawing a partial vacuum within the evaporating receptacle, and a vapor compression refrigeration system is

Melton

1982-01-01

214

Convolutional entanglement distillation  

Microsoft Academic Search

We develop a theory of entanglement distillation that exploits a convolutional coding structure. We provide a method for converting an arbitrary classical binary or quaternary convolutional code into a convolutional entanglement distillation protocol. The yield and error-correcting properties of such a protocol depend respectively on the rate and error-correcting properties of the imported classical convolutional code. In a convolutional entanglement

Mark M. Wilde; Hari Krovi; Todd A. Brun

2010-01-01

215

Non-distillable entanglement guarantees distillable entanglement  

Microsoft Academic Search

The monogamy of entanglement is one of the basic quantum mechanical features, which says that when two partners Alice and Bob are more entangled then either of them has to be less entangled with the third party. Here we qualitatively present the converse monogamy of entanglement: given a tripartite pure system and when Alice and Bob are entangled and non-distillable,

Lin Chen; Masahito Hayashi

2011-01-01

216

Optimization of reactive distillation processes with simulated annealing  

Microsoft Academic Search

A simulated annealing-based algorithm (MSIMPSA) suitable for the optimization of mixed integer non-linear programming (MINLP) problems was applied to the synthesis of a non-equilibrium reactive distillation column. A simulation model based on an extension of conventional distillation is proposed for the simulation step of the optimization problem. In the case of ideal vapor–liquid equilibrium, the simulation results are similar to

M. F. Cardoso; R. L. Salcedo; S. Feyo de Azevedo; D. Barbosa

2000-01-01

217

Stirling Cycle Cryogenic Cooler.  

National Technical Information Service (NTIS)

A long lifetime Stirling cycle cryogenic cooler particularly adapted for space applications comprised of a compressor section centrally aligned end to end with an expansion section and respectively including a reciprocating compressor piston and displacer...

A. Sherman M. G. Gasser P. A. Studer M. Goldowsky A. Daniels

1981-01-01

218

CRYOGENICS IN BEPCII UPGRADE.  

SciTech Connect

THIS PAPER PRESENTS A CRYOGENIC DESIGN FOR UPGRADING THE BEIJING ELECTRON POSITRON COLLIDER AT THE INSTITUTE OF HIGH ENERGY PHYSICS IN BEIJING. THE UPGRADE INVOLVES 3 NEW SUPERCONDUCTING FACILITIES, THE INTERACTION REGION QUADRUPOLE MAGNETS, THE DETECTOR SOLENOID MAGNETS AND THE SRF CAVITIES. FOR COOLING OF THESE DEVICES, A NEW CRYPLANT WITH A TOTAL CAPACITY OF 1.0KW AT 4.5K IS TO BE BUILT AT IHEP. AN INTEGRATED CRYOGENIC DESIGN TO FIT THE BEPCII CRYOGENIC LOADS WITH HIGH EFFICIENCY IS CARRIEDOUT USING COMPUTATIONAL PROCESS ANALYSIS SOFTWARE WITH THE EMPHASES ON ECONOMICS AND SAFETY IN BOTH CONSTRUCTION AND OPERATION OF THE PLANT. THIS PAPER DESCRIBES THE CRYOGENIC CHARACTERISTICS OF EACH SUPERCONDUCTING DEVICE, THEIR COOLING SCHEMES AND THE OVERALL CRYOPLANT.

JIA,L.; WANG,L.; LI,S.

2002-07-22

219

Recent Subjects in Cryogenics  

NASA Astrophysics Data System (ADS)

Several topics in the field of cryogenic engineering are described. Those are cryopumping and small refrigerators, Squid and its applications, large superconducting equipments such as a magnet for nuclear fusion, a magnet for NMR-CT, and magnetic refrigerators.

Nagano, Hiroshi

220

Cryogenics in space  

NASA Astrophysics Data System (ADS)

Cryogenics plays a key role on board space-science missions, with a range of applications, mainly in the domain of astrophysics. Indeed a tremendous progress has been achieved over the last 20 years in cryogenics, with enhanced reliability and simpler operations, thus matching the needs of advanced focal-plane detectors and complex science instrumentation. In this article we provide an overview of recent applications of cryogenics in space, with specific emphasis on science missions. The overview includes an analysis of the impact of cryogenics on the spacecraft system design and of the main technical solutions presently adopted. Critical technology developments and programmatic aspects are also addressed, including specific needs of future science missions and lessons learnt from recent programmes.

Rando, Nicola

221

Cryogenic Mass Flowmeter.  

National Technical Information Service (NTIS)

The report covers work performed on a cryogenic linear momentum mass flowmeter. The meter consists, primarily, of an oscillating dragbody with signal conditioning electronics. The meter theory and design are covered in detail, with design and performance ...

E. R. Wuori J. J. Rusnak

1971-01-01

222

Advances in Helium Cryogenics  

Microsoft Academic Search

This review provides a survey of major advances that have occurred in recent years in the area of helium cryogenics. Helium-temperature\\u000a cryogenics is the enabling technology for a substantial and growing number of low-temperature systems from superconducting\\u000a magnets to space-based experimental facilities. In recent years there have been many advances in the technology of low-temperature\\u000a helium, driven mostly by new

S. W. Van Sciver

223

Advanced Distillation Final Report  

SciTech Connect

The Advanced Distillation project was concluded on December 31, 2009. This U.S. Department of Energy (DOE) funded project was completed successfully and within budget during a timeline approved by DOE project managers, which included a one year extension to the initial ending date. The subject technology, Microchannel Process Technology (MPT) distillation, was expected to provide both capital and operating cost savings compared to conventional distillation technology. With efforts from Velocys and its project partners, MPT distillation was successfully demonstrated at a laboratory scale and its energy savings potential was calculated. While many objectives established at the beginning of the project were met, the project was only partially successful. At the conclusion, it appears that MPT distillation is not a good fit for the targeted separation of ethane and ethylene in large-scale ethylene production facilities, as greater advantages were seen for smaller scale distillations. Early in the project, work involved flowsheet analyses to discern the economic viability of ethane-ethylene MPT distillation and develop strategies for maximizing its impact on the economics of the process. This study confirmed that through modification to standard operating processes, MPT can enable net energy savings in excess of 20%. This advantage was used by ABB Lumus to determine the potential impact of MPT distillation on the ethane-ethylene market. The study indicated that a substantial market exists if the energy saving could be realized and if installed capital cost of MPT distillation was on par or less than conventional technology. Unfortunately, it was determined that the large number of MPT distillation units needed to perform ethane-ethylene separation for world-scale ethylene facilities, makes the targeted separation a poor fit for the technology in this application at the current state of manufacturing costs. Over the course of the project, distillation experiments were performed with the targeted mixture, ethane-ethylene, as well as with analogous low relative volatility systems: cyclohexane-hexane and cyclopentane-pentane. Devices and test stands were specifically designed for these efforts. Development progressed from experiments and models considering sections of a full scale device to the design, fabrication, and operation of a single-channel distillation unit with integrated heat transfer. Throughout the project, analytical and numerical models and Computational Fluid Dynamics (CFD) simulations were validated with experiments in the process of developing this platform technology. Experimental trials demonstrated steady and controllable distillation for a variety of process conditions. Values of Height-to-an-Equivalent Theoretical Plate (HETP) ranging from less than 0.5 inch to a few inches were experimentally proven, demonstrating a ten-fold performance enhancement relative to conventional distillation. This improvement, while substantial, is not sufficient for MPT distillation to displace very large scale distillation trains. Fortunately, parallel efforts in the area of business development have yielded other applications for MPT distillation, including smaller scale separations that benefit from the flowsheet flexibility offered by the technology. Talks with multiple potential partners are underway. Their outcome will also help determine the path ahead for MPT distillation.

Maddalena Fanelli; Ravi Arora; Annalee Tonkovich; Jennifer Marco; Ed Rode

2010-03-24

224

Distillation of binary mixtures with capillary porous plates  

SciTech Connect

Distillation of liquid mixtures using capillary porous plates is a new process which depends upon the use of the intermolecular interactions between solids and liquids to alter the normal vapor-liquid equilibrium of a given mixture. Distillation of different binary mixtures, namely ethanol-water, ethanol-benzene, and acetone-ethanol systems, of different compositions was experimentally studied in a continuous distillation column equipped with four, five, or six porous sintered stainless steel fractionating plates of 13.5 {micro}m pore diameter as well as six normal sieve plates. The results showed that the main factors affecting the separation efficiency in a given porous plate are the polarization of the pure liquids and the polarization difference between the mixture components. For the ethanol-water system, the results showed that while no separation was achieved in a distillation column with conventional stages, the zeotropic point of this system was broken in the distillation column with porous plates. A distillate of about 94 mol% ethanol was obtained for a feed of the zeotropic composition, i.e., 89.7 mol% ethanol. For the ethanol-benzene system, the azeotropic point was shifted from 40 mol% ethanol to about 30 mol% ethanol. For the acetone-ethanol system, there was no significant difference between the results obtained with normal stages and those with the porous plates. These results are in agreement with the developed theory.

Abu Al-Rub, F.A. [Jordan Univ. of Science and Technology, Irbid (Jordan). Dept. of Chemical Engineering; Akili, J.; Datta, R. [Univ. of Iowa, Iowa City, IA (United States). Dept. of Chemical and Biochemical Engineering

1998-07-01

225

Distillation of hydrogen isotopes for polarized HD targets  

NASA Astrophysics Data System (ADS)

We have developed a new cryogenic distillation system to purify Hydrogen-Deuteride (HD) gas for polarized HD targets in LEPS experiments at SPring-8. A small amount of ortho-H2 (?0.01%) in the HD gas plays an important role in efficiently polarizing the HD target. Since there are 1-5% impurities of H2 and D2 in commercially available HD gases, it is necessary to purify the HD gas up to ?99.99%. The distillation system is equipped with a cryogenic distillation unit filled with many small stainless steel cells called “Heli-pack”. The distillation unit consists of a condenser part, a rectification part, and a reboiler part. The unit is kept at the temperature of 17-21 K. The Heli-pack has a large surface area that makes a good contact between gases and liquids. An amount of 5.2 mol of commercial HD gas is fed into the distillation unit. Three trials were carried out to purify the HD gas by changing temperatures (17.5 K and 20.5 K) and gas extraction speeds (1.3 ml/min and 5.2 ml/min). The extracted gas was analyzed using a gas analyzer system combining a quadrupole mass spectrometer with a gas chromatograph. One mol of HD gas with a purity better than 99.99% has been successfully obtained for the first time. The effective NTP (Number of Theoretical Plates), which is an indication of the distillation performances, is obtained to be 37.2±0.6. This value is in good agreement with a designed value of 37.9. The HD target is expected to be efficiently polarized under a well-controlled condition by adding an optimal amount of ortho-H2 to the purified HD gas.

Ohta, T.; Bouchigny, S.; Didelez, J.-P.; Fujiwara, M.; Fukuda, K.; Kohri, H.; Kunimatsu, T.; Morisaki, C.; Ono, S.; Rouillé, G.; Tanaka, M.; Ueda, K.; Uraki, M.; Utsuro, M.; Wang, S. Y.; Yosoi, M.

2012-02-01

226

Distillation and absorption  

SciTech Connect

Two volumes, focusing on dynamics and control, packing, absorption and other mass transfer processes, synthesis and simulation, trays, and vapor liquid equilibria. These volumes are reference sources for distillation and absorption, equipment manufacture, and pharmaceuticals.

Haselden, G.G.

1988-01-01

227

Datalogging the Distillation Process.  

ERIC Educational Resources Information Center

|Presents a distillation experiment that uses temperature sensors connected to a computer in place of thermometers, and enables the whole class to view the data on a monitor and interpret and discuss the data in real time. (JRH)|

Soares, Allan; Creevy, Steven

1995-01-01

228

Convolutional Entanglement Distillation  

Microsoft Academic Search

We develop a theory of entanglement distillation that exploits a convolutional coding structure. We provide a method for converting an arbitrary classical binary or quaternary convolutional code into a convolutional entanglement distillation protocol. The imported classical convolutional code does not have to be dual-containing or self-orthogonal. The yield and error-correcting properties of such a protocol depend respectively on the rate

Mark M. Wilde; Hari Krovi; Todd A. Brun

2007-01-01

229

High-Purity Distillation  

Microsoft Academic Search

Distillation is one of the most common separation techniques in chemical manufacturing. This multi-input, multi-output staged separation process is strongly interactive, as determined by the singular value decomposition of a linear dynamic model of the system. Process dynamics associated with the low-gain direction are critical to the design of high-performance controllers for high-purity distillation but are difficult to estimate from

DANIEL E. RIVERA; Hyunjin Lee; HANS D. MITTELMANN; MARTIN W. BRAUN

2007-01-01

230

Flooding Characteristics of Packed Columns with High Efficiency.  

National Technical Information Service (NTIS)

Flooding characteristics of four high efficiency column packings, including Scientific Development Co. (SDC) protruded stainless distillation packing, Norton stainless pall rings, Podbielniak bronze Helipak, and Goodloe stainless wire mesh packing were de...

W. M. Choi R. C. Michel J. L. P. Varlet

1976-01-01

231

Method of improving thermal efficiency of sidedraw fractionating columns  

SciTech Connect

An improved process for the fractional distillation of a multicomponent liquid in a multiple tray fractional distillation column having at least one sidedraw tray is disclosed, the process being characterized by elimination of draw tray overflow from at least one sidedraw tray, provision of a circulating reflux, and removal of reflux from the locus of the circulating reflux withdrawal zone.

Bannon, R.P.

1981-12-29

232

40 CFR 721.4500 - Isopropylamine distillation residues and ethylamine distillation residues.  

Code of Federal Regulations, 2010 CFR

... 2009-07-01 false Isopropylamine distillation residues and ethylamine distillation residues. 721.4500 Section 721...Substances § 721.4500 Isopropylamine distillation residues and ethylamine distillation...

2009-07-01

233

40 CFR 721.4500 - Isopropylamine distillation residues and ethylamine distillation residues.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Isopropylamine distillation residues and ethylamine distillation residues. 721.4500 Section 721...Substances § 721.4500 Isopropylamine distillation residues and ethylamine distillation...

2010-07-01

234

Cryogenics for Fusion  

NASA Astrophysics Data System (ADS)

Fusion of Hydrogen to produce energy is one of the technologies under study to meet the mankind raising need in energy and as a substitute to fossil fuels for the future. This technology is under investigation for more than 30 years already, with, for example, the former construction of the experimental reactors Tore Supra, DIII-D and JET. With the construction of ITER to start, the next step to ``fusion for energy'' will be done. In these projects, an extensive use of cryogenic systems is requested. Air Liquide has been involved as cryogenic partner in most of former and presently constructed fusion reactors. In the present paper, a review of the cryogenic systems we delivered to Tore Supra, JET, IPR and KSTAR will be presented.

Dauguet, P.; Gistau-Baguer, G. M.; Bonneton, M.; Boissin, J. C.; Fauve, E.; Bernhardt, J. M.; Beauvisage, J.; Andrieu, F.

2008-03-01

235

Cryogenic engineering and fusion power  

Microsoft Academic Search

In order to reduce the consumption of power for the magnets of a fusion power plant to acceptable proportions, it is necessary that fusion reactors must use either cryogenically cooled or superconducting coils. The cryogenic aspects of reactor design are discussed. It is found that the most difficult cryogenic engineering problems of fusion reactors are mainly those caused by the

C. E. Taylor

1974-01-01

236

Latest Developments in Cryogenic Safety.  

National Technical Information Service (NTIS)

The Cryogenic Safety Manual, sponsored by the British Cryogenics Council, was published over 10 years ago. A new updated version is now available. Some general aspects of cryogenic safety are highlighted, and attention is drawn to some of the more unusual...

T. J. Webster

1983-01-01

237

Safety and Cryogenic Wind Tunnels.  

National Technical Information Service (NTIS)

The Langley 0.3-Meter Transonic Cryogenic Tunnel (0.3-m TCT) was placed in operation at NASA's Langley Research Center in 1973 as the world's first cryogenic pressure tunnel. The 0.3-m TCT can operate from ambient to cryogenic temperatures over an absolut...

E. J. Ray

1989-01-01

238

OGMS of cryogenically enhanced magnetics  

Microsoft Academic Search

The magnetic susceptibility of paramagnetic particles is enhanced by cryogenic treatment. The subsequent increased response to a magnetic force density is exploited to enhance particle deflection in open gradient magnetic separation (OGMS). Both grade and recovery values are considerably increased by the cryogenic treatment of the feed material. The cryogenic method is most useful if the response of the magnetic

P. Krist; J. Boehm; R. Gerber; D. R. Kelland

1992-01-01

239

Design of heat integrated distillation systems for a light ends separation plant  

Microsoft Academic Search

This paper presents an industrial case-study: the synthesis of partially thermally coupled and heat-integrated distillation systems applied to the light ends separation section of a crude distillation plant. The distillation systems presented in this work employ the thermal coupling and the heat-integration principles to significantly reduce the heat requirements with respect to the traditional simple column train.The work started from

Michele Mascia; Francesca Ferrara; Annalisa Vacca; Giuseppe Tola; Massimiliano Errico

2007-01-01

240

Integration and Testing of a Cogenerating Concentrating Solar Collector with Advanced Alcohol-Distillation Equipment.  

National Technical Information Service (NTIS)

An advanced concept of vapor recompression of alcohol in a distillation column has been demonstrated. Its potential as a primary method separating alcohol from water lies in its operational simplicity, potential for automation, and low operating cost. Tho...

W. Rogers D. N. Borton

1983-01-01

241

Cryogenic support member  

SciTech Connect

A cryogenic support member is described for restraining a cryogenic system comprising; a rod having a depression at a first end. The rod is made of non-metallic material. The non-metallic material has an effectively low thermal conductivity; a metallic plug; and a metallic sleeve. The plug and the sleeve are shrink-fitted to the depression in the rod and assembled thereto such that the plug is disposed inside the depression of the rod. The sleeve is disposed over the depression in the rod and the rod is clamped therebetween. The shrink-fit clamping the rod is generated between the metallic plug and the metallic sleeve.

Niemann, R.C.; Gonczy, J.D.; Nicol, T.H.

1987-09-29

242

Unique Cryogenic Welded Structures  

NASA Astrophysics Data System (ADS)

For the last few decades, the E. O. Paton Electric Welding Institute has been active in the field of cryogenic materials science. Integrated research on development of new grades of steels and alloys for cryogenic engineering was carried out in collaboration with the leading institutions of Russia, Ukraine, and Georgia. Commercially applied welding technologies and consumables were developed. They include large, spherical tanks for storage of liquefied gases (from oxygen to helium) under high pressures; space simulators with a capacity of 10 000 m3 and more; and load-carrying elements of superconducting fusion magnetic systems for the TOKAMAK, MGD, and ITER series.

Yushchenko, K. A.; Monko, G. G.

2004-06-01

243

Microbial activity in weathering columns.  

PubMed

The aim of the present work was to evaluate the metabolic activity of the microbial population associated with a pyritic tailing after a column-weathering test. For this purpose, a column 150cm high and 15cm diameter was used. The solid was a tailing with 63.4% pyrite and with minor amounts of Cu, Pb and Zn sulfides (1.4, 0.5 and 0.8%, respectively). The column model was the habitual one for weathering tests: distilled water was added at the top of the column; the water flowed down through tailings and finally was collected at the bottom for chemical and microbiological analysis. Weathering was maintained for 36 weeks. The results showed a significant presence of microbial life that was distributed selectively over the column: sulfur- and iron-oxidizing aerobic bacteria were in the more oxygenated zone; anaerobic sulfur-reducing bacteria were isolated from the samples taken from the anoxic part of the column. Activity testing showed that (oxidizing and reducing) bacteria populations were active at the end of the weathering test. The quality of the water draining from the column was thus the final product of biological oxidation and reduction promoted by the bacteria consortia. PMID:16949201

García, C; Ballester, A; González, F; Blázquez, M L

2006-07-14

244

Effect of recycle streams on energy performance and closed loop dynamics of distillation sequences  

Microsoft Academic Search

This paper presents the retrofit of five conventional distillation trains for the separation of quaternary mixtures of hydrocarbons for feed compositions with high or low content of intermediate components. The retrofit implies the incorporation of liquid or vapour recycle streams among the conventional distillation columns. Each recycle stream removes one condenser or one reboiler. The introduction of thermal links can

S. Hernández; J. G. Segovia-Hernández; J. Carlos Cárdenas; V. Rico-Ramírez

2005-01-01

245

Analysis of closed multivessel batch distillation of ternary azeotropic mixtures using elementary VLE cells  

Microsoft Academic Search

Introducing the concept of elementary topological cells, we illustrate how vapor-liquid equilibrium (VLE) diagrams like distillation lines and isotherms maps may be used in analysis of the closed (total reflux) multivessel batch distillation column. An indirect level control strategy is implemented that eliminates the need for pre-calculated vessel holdups and makes the closed operating policy flexible and simple to implement

E. K. Hilmen; V. N. Kiva; S. Skogestad

1999-01-01

246

A REACTIVE DISTILLATION PROCESS FOR AN AZEOTROPIC REACTION SYSTEM: TRANSESTERIFICATION OF ETHYLENE CARBONATE WITH METHANOL  

Microsoft Academic Search

A reactive distillation process is proposed for manufacturing dimethyl carbonate (DMC) through the transesterification reaction of ethylene carbonate (EC) with methanol. Modeling and simulation of the reactive distillation column have been carried out to study the effects of operating conditions, such as the reflux ratio, the number of theoretical plates, the feed ratio, the top effluent, the liquid holdup, and

Yun-Jin Fang; Dao-Jun Liu

2007-01-01

247

Feasibility of separations for distillation of nonideal ternary mixtures  

SciTech Connect

The product compositions in single-feed distillation columns can be specified only in certain regions of the composition space, which depend only on the pressure, feed, and vapor-liquid equilibrium for the mixture. In nonideal mixtures, even without azeotropes, the regions may allow unusual product distributions. For example, the distillate in a direct split is composed primarily of the lightest component. Intuition and experience with relatively ideal mixtures suggest that the next most plentiful component is the intermediate boiler. In nonideal mixtures, however, with or without azeotropes, the next most plentiful component may be the highest-boiling species with only trace amounts of the intermediate boiler. For azeotropic mixtures, distillation boundaries may give rise to additional restrictions on the product compositions. The authors describe how simple distillation boundaries deform into continuous distillation boundaries and, in a limited number of cases, how the simple distillation boundaries can be crossed in continuous columns for certain ranges of the design variables. Unfortunately, such designs may be quite sensitive to model uncertainties or to disturbances in the parameters.

Fidkowski, Z.T.; Doherty, M.F.; Malone, M.F. (Univ. of Massachusetts, Amherst, MA (United States). Dept. of Chemical Engineering)

1993-08-01

248

Cumene by catalytic distillation  

SciTech Connect

Chemical Research and Licensing Co. (CR and L) began developing its catalytic distillation technology in 1978. The first commercially significant application was for the manufacture of methyl tertiary butyl ether (MTBE), which started up in a Houston refinery in 1981. This unit has operated successfully, since then several other MTBE Units have gone into service. During the last two years, CR and L has worked intensively on development of aromatics alkylation by catalytic distillation, with specific emphasis on the manufacture of cumene. Previous papers have described the catalytic distillation process as applied to MTBE manufacture. This paper presents the advantages of the CR and L cumene process compared to some others which are widely used in the U.S. today.

Shoemaker, J.D.; Jones, E.M. Jr.

1987-01-01

249

Trajan's Column  

NSDL National Science Digital Library

This Website, from McMaster University, uses the combined skills of artists, writers, programmers, and Web designers to create a resource for the study of Trajan's column, a Roman architectural monument. This 100-foot marble column, built during the reign of Emperor Trajan, 98-117 AD, is topped with a gilded statue of Trajan and decorated with carvings recounting Trajan's rule, primarily the Dacian Wars and his building projects. The heart of the Website is the database of 500 slides of the carvings; indexes allow users to view the slides in thematic groupings such as images of sides of the column, groups organized by subject keywords, or carvings made with specific tools. Cartoons or drawings of the column help to contextualize the details found in the slides, and essays provide more information on its design, construction, and preservation.

250

Cumene by Catalytic Distillation  

SciTech Connect

The novel concept of Catalytic Distillation has been commercialized in the CRandL MTBE process, in which combined reaction and distillation provide energy savings over conventional processes. This concept has now been extended to production of cumene from benzene and propylene. In this case the advantages of the technique are not only energy savings but significant reductions in by-product losses and capital requirements. In this paper the development of the process is discussed and the economics of commercial operation are presented.

Jones, E.M.; Mawer, J.

1986-01-01

251

Efficient distillation beyond qubits  

SciTech Connect

We provide generalizations of known two-qubit entanglement distillation protocols for arbitrary Hilbert space dimensions. The protocols, which are analogs of the hashing and breeding procedures, are adapted to bipartite quantum states that are diagonal in a basis of maximally entangled states. We show that the obtained rates are optimal, and thus equal to the distillable entanglement, for a (d-1)-parameter family of rank deficient states. Methods to improve the rates for other states are discussed. In particular, for isotropic states it is shown that the rate can be improved such that it approaches the relative entropy of entanglement in the limit of large dimensions.

Vollbrecht, Karl Gerd H.; Wolf, Michael M. [Institute for Mathematical Physics, TU Braunschweig, Braunschweig (Germany)

2003-01-01

252

Dynamic simulation for reactive distillation with ETBE synthesis  

Microsoft Academic Search

Ethyl tert-butyl ether (ETBE) is given growing attentions to as a gasoline oxygenate and an octane enhancer. The synthesis of ether such as ETBE through reactive distillation (RD) offers several advantages of the higher conversion, the improved energy efficiency, the lower capital cost and so on. A dynamic simulation was performed for a RD column with ETBE synthesis. The RD

Young H. Jhon; Tae-hee Lee

2003-01-01

253

Synthesis of nonequilibrium reactive distillation processes by MINLP optimization  

Microsoft Academic Search

A mixed integer nonlinear programming (MINLP) model is presented for synthesizing reactive distillation columns when chemical reaction equilibrium cannot be assured. The MINLP minimizes the total annual cost subject to a rigorous tray-by-tray model. The solution of this MINLP yields the optimal number of trays, the optimal feed rates, and the optimal feed tray locations. The liquid holdup per tray,

Amy R. Ciric; Deyao Gu

1994-01-01

254

A cyclic operating policy for batch distillation — Theory and practice  

Microsoft Academic Search

This paper sets out a cyclic operation policy for batch distillation with repeated filling and dumping of the reflux drum. The cyclic policy has several advantages compared to conventional schemes; it achieves the maximum attainable separation in the column; there is a minimal need for control and it is less sensitive to disturbances and therefore safer to operate. For small

E. Sørensen; M. Prenzler

1997-01-01

255

Cryogenic Grating Spectrometer.  

National Technical Information Service (NTIS)

The Cryogenic Grating Spectrometer (CGS) first flew on the KAO in 1982 December and has been open to guest investigators since 1984 October. In the past 12 years it has completed over 100 research flights supporting 13 different principal investigators st...

E. F. Erickson M. R. Haas S. W. J. Colgan J. P. Simpson R. H. Rubin

1995-01-01

256

Compact cryogenic inductors  

SciTech Connect

Power systems requiring power levels as high as a few megawatts to a few gigawatts for periods of several microseconds to several milliseconds with repetitive frequencies of a few hertz to a few kilohertz are being considered for potential space applications. The impulsive nature of the power presents the opportunity to use inductive energy storage techniques for pulse duty to enhance economic and practical considerations. An inductors must be efficient, lightweight, and reliable, and it must have high energy density if it is to be used in space based power systems. Cryogenic inductors are best studied for such an application. Parametric analyses of the two potential types of cryogenic inductors (superconducting and hyperconducting reveal that the hyperconducting (high purity aluminum)) inductor would be significantly lighter and achieve higher energy densities without the added penalty of a helium refrigeration system, thus resulting in improved overall system reliability. The lightweight hyperconducting cryogenic inductor technology is, however, in its infancy. This paper describes the required technology base which would allow the eventual application of the lightweight cryogenic inductor in space power systems, and also conclusively demonstrates the underlying principles.

Singh, S.K.; Carr, W.J. Jr.; Fagan, T.J. Jr.; Hordubay, T.D.; Chuboy, H.L. (Westinghouse Electric Corp., Pittsburgh, PA (United States). Science and Technology Center)

1994-07-01

257

Cryogenic Gravity Meter.  

National Technical Information Service (NTIS)

The report describes a cryogenic gravity meter which has a theoretical sensitivity of about 25 millimicrogal. The instrument consists of two parts--a suspension unit and a detection module. There are nine other units of power supplies, amplifiers, and oth...

A. Waleh V. S. Tuman

1971-01-01

258

Ultrastable Cryogenic Microwave Oscillators  

Microsoft Academic Search

Ultrastable cryogenic microwave oscillators are secondary frequency standards in the microwave domain. The best of these oscillators have demonstrated a short term frequency stability in the range 10-14 to a few times 10-16. The main application for these oscillators is as flywheel oscillators for the next generation of passive atomic frequency standards, and as local oscillators in space telemetry ground

Anthony G. Mann

2001-01-01

259

Cryogenic Implications for DT.  

National Technical Information Service (NTIS)

Cryogenic hydrogen data is being compiled for magnetic fusion engineering. Many physical properties of DT can be extrapolated from H sub 2 and D sub 2 values. The phase diagram properties of the D sub 2 -DT-T sub 2 mixture are being measured. Three proper...

P. C. Souers

1977-01-01

260

Cryogenic vacuum pump design  

Microsoft Academic Search

This paper is a review of the problems and tradeoffs involved in cryogenic vacuum pump analysis, design and manufacture. Particular attention is paid to the several issues unique to cryopumps, e.g., radiation loading, adsorption of noncondensible gases, and regeneration. A general algorithm for cryopump design is also proposed.

A. J. Bartlett; P. A. Lessard

1984-01-01

261

Cryogenic structural support  

SciTech Connect

A tensile support member is provided for use in a cryogenic environment. The member is in the form of a link formed of an epoxy glass laminate with at least one ply of the laminate having its fibers aligned circumferentially about the link.

Gonczy, J.D.; Mataya, K.F.; Niemann, R.C.

1982-04-20

262

Distillation under electric fields  

SciTech Connect

Distillation Is the most common separation process used in the chemical and petroleum industry. Major limitations in the applicability and efficiency of distillation come from thermodynamic equilibria, that is, vapor-liquid equilibria (VLE), and heat and mass transfer rates. In this work, electric fields are used to manipulate the VLE of mixtures. VLE experiments are performed for various binary mixtures in the presence of electric fields on the order of a few kilovolts per centimeter. The results show that the VLE is changed by electric fields, with changes in the separation factor as high as 10% being observed. Batch distillation experiments are also carried out for binary mixtures of 2-propanol and water with and without an applied electric field. Results show enhanced distillation rates and separation efficiency in the presence of an electric field but decreased separation enhancement when the electric current is increased. The latter phenomenon is caused by the formation at the surface of the liquid mixture of microdroplets that are entrained by the vapor. These observations suggest that there should be an electric field strength for each system for which the separation enhancement is maximum.

Shah, V.M. [Univ. of Tennessee, Knoxville, TN (United States). Chemical Engineering Dept.; Blankenship, K.D.; Tsouris, C. [Oak Ridge National Lab., TN (United States)

1997-11-01

263

Tritium Attenuation by Distillation  

SciTech Connect

The objective of this study was to determine how a 100 Area distillation system could be used to reduce to a satisfactory low value the tritium content of the dilute moderator produced in the 100 Area stills, and whether such a tritium attenuator would have sufficient capacity to process all this material before it is sent to the 400 Area for reprocessing.

Wittman, N.E.

2001-07-31

264

Distill Salt Water  

NSDL National Science Digital Library

In this activity, conduct an experiment to make freshwater out of saltwater. First, make saltwater and then seal it and place it in the Sun for a couple of hours or even a whole day. This solar still will distill, or purify, the water. Use this activity to explore water purification and evaporation. This activity guide includes a step-by-step instructional video.

Center, Saint L.

2013-01-17

265

Solar distillation in Brasil  

Microsoft Academic Search

Solar stills are found to be a more economical means of providing fresh water than flash distillation, reverse osmosis or vapor compression when daily requirements amount to less than 100 cu m. The basin-type solar still design examined in this paper involves simple construction and inexpensive materials. More efficient than the simple solar still is the multiple-effect still, which relies

P. J. Catania; P. C. Lobo

1979-01-01

266

Preprototype Vapor Compression Distillation Subsystem.  

National Technical Information Service (NTIS)

A three-person capacity preprototype vapor compression distillation subsystem for recovering potable water from wastewater aboard spacecraft was designed, assembled, and tested. The major components of the subsystem are: (1) a distillation unit which incl...

G. S. Ellis R. A. Wynveen F. H. Schubert

1979-01-01

267

Cryogenic support system  

DOEpatents

A support system is disclosed for restraining large masses at very low or cryogenic temperatures. The support system employs a tie bar that is pivotally connected at opposite ends to an anchoring support member and a sliding support member. The tie bar extends substantially parallel to the longitudinal axis of the cold mass assembly, and comprises a rod that lengthens when cooled and a pair of end attachments that contract when cooled. The rod and end attachments are sized so that when the tie bar is cooled to cryogenic temperature, the net change in tie bar length is approximately zero. Longitudinal force directed against the cold mass assembly is distributed by the tie bar between the anchoring support member and the sliding support member.

Nicol, Thomas H. (Aurora, IL); Niemann, Ralph C. (Downers Grove, IL); Gonczy, John D. (Oak Lawn, IL)

1988-01-01

268

Flexible cryogenic conduit  

SciTech Connect

A flexible and relatively low cost cryogenic conduit is described. The flexible cryogenic conduit of the present invention comprises a first inner corrugated tube with single braided serving, a second outer corrugated tube with single braided serving concentric with the inner corrugated tube, and arranged outwardly about the periphery of the inner corrugated tube and between the inner and outer corrugated tubes: a superinsulation layer; a one half lap layer of polyester ribbon; a one half lap layer of copper ribbon; a spirally wound refrigeration tube; a second one half lap layer of copper ribbon; a second one half lap layer of polyester ribbon; a second superinsulation layer; a third one half lap layer of polyester ribbon; and a spirally wound stretchable and compressible filament.

Brindza, P.D.; Wines, R.R.; Takacs, J.J.

1999-12-21

269

Cryogenic thermal diodes  

NASA Astrophysics Data System (ADS)

Space based cryogenic thermal management systems for advanced infrared sensor platforms are a critical failure mode to the spacecraft missions they are supporting. Recent advances in cryocooler technologies have increased the achievable cooling capacities and decreased the operating temperatures of these systems, but there is still a fundamental need for redundancy in these systems. Cryogenic thermal diodes act as thermal switches, allowing heat to flow through them when in a conduction mode and restricting the flow of heat when in an isolation mode. These diodes will allow multiple cryocoolers to cool a single infrared focal plane array. The Space Dynamics Laboratory has undertaken an internal research and development effort to develop this innovative technology. This paper briefly describes the design parameters of several prototype thermal diodes that were developed and tested. .

Paulsen, Brandon R.; Batty, J. C.; Agren, John

2000-01-01

270

Cryogenic treatment of gas  

SciTech Connect

Systems and methods of treating a gas stream are described. A method of treating a gas stream includes cryogenically separating a first gas stream to form a second gas stream and a third stream. The third stream is cryogenically contacted with a carbon dioxide stream to form a fourth and fifth stream. A majority of the second gas stream includes methane and/or molecular hydrogen. A majority of the third stream includes one or more carbon oxides, hydrocarbons having a carbon number of at least 2, one or more sulfur compounds, or mixtures thereof. A majority of the fourth stream includes one or more of the carbon oxides and hydrocarbons having a carbon number of at least 2. A majority of the fifth stream includes hydrocarbons having a carbon number of at least 3 and one or more of the sulfur compounds.

Bravo, Jose Luis (Houston, TX); Harvey, III, Albert Destrehan (Kingwood, TX); Vinegar, Harold J. (Bellaire, TX)

2012-04-03

271

Ultrastable Cryogenic Microwave Oscillators  

Microsoft Academic Search

Ultrastable cryogenic microwave oscillators are secondary frequency standards in the microwave domain. The best of these oscillators\\u000a have demonstrated a short term frequency stability in the range 10?14 to a few times 10?16. The main application for these oscillators is as flywheel oscillators for the next generation of passive atomic frequency\\u000a standards, and as local oscillators in space telemetry ground

Anthony Mann

272

Cryogenic support member  

DOEpatents

A cryogenic support member is comprised of a nonmetallic rod having a depression in at least one end and a metallic end connection assembled to the rod. The metallic end connection comprises a metallic plug which conforms to the shape and is disposed in the depression and a metallic sleeve is disposed over the rod and plug. The plug and the sleeve are shrink-fitted to the depression in the rod to form a connection good in compression, tension and bending.

Niemann, R.C.; Gonczy, J.D.; Nicol, T.H.

1986-05-15

273

Cryogenic infrared grating spectrometer.  

PubMed

A liquid-helium-cooled Ebert-Fastie grating spectrometer for use in a sounding rocket is described. Twelve detectors and associated filters separate the 5-70-microm spectral range into twelve intervals, each of which is scanned as the grating is rotated. The instrument was launched into an aurora from Fort Churchill, Canada, but a cryogenic failure occurred early in the flight, and only a small amount of data was obtained. PMID:20154781

McNutt, D P; Shivanandan, K; Daehler, M; Feldman, P D

1975-05-01

274

Cryogenic infrared grating spectrometer  

Microsoft Academic Search

A liquid-helium-cooled Ebert-Fastie grating spectrometer for use in a sounding rocket is described. Twelve detectors and associated filters separate the 5-70-micrometer spectral range into twelve intervals, each of which is scanned as the grating is rotated. The instrument was launched into an aurora from Fort Churchill, Canada, but a cryogenic failure occurred early in the flight, and only a small

D. P. McNutt; K. Shivanandan; M. Daehler; P. D. Feldman

1975-01-01

275

Advances in Helium Cryogenics  

NASA Astrophysics Data System (ADS)

This review provides a survey of major advances that have occurred in recent years in the area of helium cryogenics. Helium-temperature cryogenics is the enabling technology for a substantial and growing number of low-temperature systems from superconducting magnets to space-based experimental facilities. In recent years there have been many advances in the technology of low-temperature helium, driven mostly by new applications. However, to keep the review from being too broad, this presentation focuses mainly on three of the most significant advances. These are: (1) the development of large-scale recuperative refrigeration systems mainly for superconducting magnet applications in accelerators and other research facilities; (2) the use of stored superfluid helium (He II) as a coolant for spacebased astrophysics experiments; and (3) the application of regenerative cryocoolers operating at liquid helium temperatures primarily for cooling superconducting devices. In each case, the reader should observe that critical technologies were developed to facilitate these applications. In addition to these three primary advances, other significant helium cryogenic technologies are briefly reviewed at the end of this chapter, along with some vision for future developments in these areas.

Sciver, S. W. Van

276

Cryogenic technology for CMBPol  

NASA Astrophysics Data System (ADS)

Future space telescopes such as CMBPol, SAFIR, DARWIN, SPICA and XEUS will require cooling to very low temperatures. Staged cooling is the most efficient means of achieving low temperature in an observatory or instrument with the least cost and mass. The first stage is usually passive radiators taking advantage of views to deep space. In the past stored cryogen systems provided the next lower stagesof cooling. Mechanical cryocoolers represent a significant enabling technology, especially at the lower temperatures where the passive coolers' effectiveness is limited. These coolers are in general lighter, have more cooling capability, and more operationally flexible than stored cryogens. Sub Kelvin cooling is required for many of the most sensitive detectors. For fundamental reasons, microcalorimeters and bolometers must be cooled to extremely low temperature to achieve their ultimate resolution and, eventually, background-limited detection. The state of the art for these cryogenic cooling technologies are presented along with plans to advance the technology readiness level to enable these future missions.

Di Pirro, M.; Johnson, D. L.; Shirron, P.

2009-03-01

277

Heterogeneous control and qualitative supervision, application to a distillation column  

Microsoft Academic Search

This paper addresses the following control problem: a continuous plant (P) is to be controlled via heterogeneous control law. The heterogeneous control laws apply even in the presence of incomplete knowledge of the system. This approach is based only on the knowledge of the physical boundaries of system input and output, and the maximum rate-of-change of the input. The qualitative

Flávio Neves Junior; Joseph Aguilar Martin

2000-01-01

278

Simulating heat and mass transfer in regular distillation column packing  

Microsoft Academic Search

Plane-parallel packing of Mellapack 250X type (without perforations) is considered. Equation systems are given that describe\\u000a the motion and heat and mass transfer in a layer of liquid and vapor. Calculations have been performed on nonstationary heat\\u000a and mass transfer in cells of several types by the use of the STAR-CD software and the subroutines Star-Design and Pro-amm.\\u000a Graphs are

I. A. Arkharov; E. S. Navasardyan

2006-01-01

279

Graph theory and model simplification. Case study: distillation column  

Microsoft Academic Search

A generic system can be seen as a set of capacities exchanging extensive quantities through connecting streams. This kind of vision can be applied with different levels of detail, focusing on smaller or bigger control volumes according on how well the dynamics of the process must be. In this way the studied system can be represented as a graph, each

Ivan Dones; Heinz A. Preisig

2009-01-01

280

Simulation, design, and analysis of azeotropic distillation operations  

SciTech Connect

The computational tools needed for simulation, design, and analysis of azeotropic distillation operations are described. These tools include simple methods to identify the existence of binary and ternary azeotropes and to classify ternary mixtures as homogeneous or heterogeneous. The tools also include more complex methods to compute the phase diagram (or a heterogeneous liquid boiling surface), predict liquid-vapor phase equilibrium, and/or predict liquid-liquid-vapor phase equilibrium for simulations of batch and continuous distillation column operations. Important new features of these tools are the incorporation of a fast and efficient method for test of phase stability in simulation of distillation operations, the ability to handle a large range of mixtures (including mixtures with supercritical compounds), and the ability for computations covering wide ranges of temperature and pressure. On the basis of these tools, simple and consistent design algorithms are developed. The applicability of the design algorithms is verified through process simulation and analysis of the predicted behavior and data from the open literature. Conditions are given for examples illustrating (when and how possible distillation boundaries can be crossed) how multiple steady states can be obtained. Finally, the effect of changes in operating on the dynamic behavior of the azeotropic distillation columns and the sensitivity of design to the prediction of phase equilibria are presented.

Bossen, B.S.; Joergensen, S.B.; Gani, R. (Technical Univ. of Denmark, Lyngby (Denmark))

1993-04-01

281

Batch distillation employing cyclic rectification and stripping operations.  

PubMed

Several strategies have been proposed to increase the operating efficiency of batch distillation. In this study, conventional batch rectification and inverted batch stripping are used cyclically to promote high product flow rates for a binary fractionation. Process controls are implemented to maintain constant product purity specifications by varying the slope of the operating line. While rectifying, the light component is removed as distillate, concentrating the heavy component in the reboiler. As a result, the distillate rate decreases with time. The column is then changed from rectification to stripping modes, and the heavy component is removed as bottoms product, concentrating the light component in the distillate drum. This causes the bottoms rate to diminish with time, and the column is once again converted back to rectifying mode. Cyclic operation, transitioning from batch rectifying to stripping back to rectifying, continues until all of the initial charge is fractionated or is combined with a new charge. The fractionation of ethanol and 1-propanol using the proposed operating strategy is shown to provide several advantages including energy and time savings when compared to conventional batch or inverted batch distillation alone. PMID:22261008

Flodman, Hunter R; Timm, Delmar C

2012-01-18

282

Silicon isotope separation by distillation of silicon tetrafluoride  

SciTech Connect

Silicon isotopes were separated by distilling silicon tetrafluoride in a 150-cm packed column at temperatures of 189-206 K. The data show a reverse isotope effect with heavy isotopes more volatile in this temperature range. At total reflux, the maximum column separations were 0.926 for {sup 28}Si/{sup 29}Si and 0.872 for {sup 28}Si/{sup 30}Si. Carbon monoxide was also distilled in the column to obtain an estimated number of separating stages. From an estimated HETP of 2 cm for the packing, the volatility of {sup 28}Si is 0.9990 relative to {sup 29}Si and 0.9982 relative to {sup 30}Si. The SiF{sub 4} isotope effect is the largest yet found in distilling silicon compounds, and the effect is opposite that seen for SiH{sub 4}. The magnitude of the isotopic relative volatilities is large enough to consider SiF{sub 4} distillation as a practical method for silicon isotopic enrichment. This effect of higher mass isotopes being more volatile has analogues in isotope effects in SF{sub 4} and BF{sub 3}.

Mills, T.R. (Los Alamos National Lab., NM (USA))

1990-03-01

283

An Analogy between Fractional Distillation and Separating Physically Fit and Physically Less Fit Persons  

Microsoft Academic Search

Separating two liquids in a fractional distillation column on the basis of their difference in boiling points is analogous to separating a group of people on the basis of their physical fitness by making them climb a flight of stairs. Several aspects of this unit operation such as column height, flooding, and reflux ratio are explained with the help of

Doble Mukesh

2001-01-01

284

Synthesis of crystallization-distillation hybrid separation processes  

SciTech Connect

A systematic method to synthesize crystallization-distillation hybrid separation processes is presented. Two classes of hybrids are identified for binary mixtures. The first bypasses azeotropes and tangent pinches, while the second bypasses eutectics. Guidelines for flow-sheet selection are proposed based on an analysis of simple eutectic, constant relative volatility systems. In addition, the hybrids are compared to both extractive and adductive crystallization in order to determine the conditions under which solvent-based crystallization techniques outperform the proposed hybrid configurations. The method is extended to ternary mixture. The use of stream combination and complex distillation columns is also considered.

Berry, D.A.; Ng, K.M. [Univ. of Massachusetts, Amherst, MA (United States). Dept. of Chemical Engineering

1997-07-01

285

Systems and methods for reactive distillation with recirculation of light components  

DOEpatents

Systems and methods for producing gas-to-liquids products using reactive distillation are provided. The method for producing gas-to-liquids products can include reacting a feedstock in a column having a distillation zone and a reaction zone to provide a bottoms stream and an overhead stream. A first portion of the overhead stream can be recycled to the column at the top of the reaction zone and second portion of the overhead stream can be recycled to the column at the bottom of the reaction zone.

Stickney, Michael J. (Nassau Bay, TX); Jones, Jr., Edward M. (Friendswood, TX)

2011-07-26

286

Cryogenic foam insulation: abstracted publications  

Microsoft Academic Search

A group of documents were chosen and abstracted which contain information on the properties of foam materials and on the use of foams as thermal insulation at cryogenic temperatures. The properties include thermal properties, mechanical properties, and compatibility properties with oxygen and other cryogenic fluids. Uses of foams include applications as thermal insulation for spacecraft propellant tanks, and for liquefied

1977-01-01

287

Thermodynamic foundations of cryogenic engineering  

Microsoft Academic Search

Cryogenic systems and their elements are examined in terms of general principles underlying their operation and characteristics, as well as their basic structure and efficiency. Special consideration is given to the thermodynamic properties of substances used in cryogenic systems, methods of thermodynamic analysis, thermomechanical methods of refrigeration, and refrigeration techniques based on quantum, magnetic, and electrocaloric effects. Microcryogenic systems, gas

V. M. Brodianskii; A. M. Semenov

1980-01-01

288

Cryogenic forced convection refrigerating system  

SciTech Connect

This patent describes the method of refrigerating products by contact with a refrigerating gas which comprises introducing product into a refrigeration zone, contacting the product with the refrigerating gas for a sufficient time to refrigerate it to the appropriate extent and removing the refrigerated product. The improvement for producing the refrigeration gas from a liquid cryogen such that essentially all of the liquid cryogen is fully vaporized before contacting the product comprises: (a) introducing the liquid cryogen, selected from the group consisting of liquid air and liquid nitrogen, at elevated pressure into an ejector as the motive fluid to accelerate a portion of a warm refrigerating gas through the ejector while mixing the cryogen and gas to effect complete vaporization of the liquid cryogen and substantial cooling of the portion of the refrigerating gas resulting in a cold discharge gas which is above the liquefaction temperature of the cryogen; (b) introducing the cold discharge gas into a forced circulation pathway of refrigerating gas and producing a cold refrigerating gas which contacts and refrigerates product and is then at least partially recirculated; (c) sensing the temperature of the refrigerating gas in the forced circulation pathway and controlling the introduction of liquid cryogen with regard to the sensed temperature to maintain the temperature of the discharge gas above the liquefacton temperature of the cryogen utilized.

Klee, D.J.

1988-02-23

289

Temperature control of cryogenic systems  

Microsoft Academic Search

A cryogenic refrigerator is described comprising: a refrigerator heat sink; a source of refrigerant gas under pressure; gas expansion means including a reciprocating piston in a cylinder for expanding the refrigerant gas in a gas expansion space within the cylinder to cool the gas and the refrigerator heat sink to cryogenic temperatures; means for selectively diverting refrigerant gas away from

P. A. Lessard; A. J. Bartlett; J. F. Peterson

1987-01-01

290

MEGARA Cryogenic System  

NASA Astrophysics Data System (ADS)

MEGARA (Multi Espectrógrafo en GTC de Alta Resolución para Astronomía) is the new integral field unit (IFU) and multi-object spectrograph (MOS) instrument for the Gran Telescopio Canarias (GTC). The selected cryogenic device to harbor the CCD detector for the MEGARA spectrograph is a liquid nitrogen open-cycle cryostat. The LN2 open-cycle cryostat is a custom made product which has been designed by the INAOE astronomical instrumentation group. The proposed cryostat offers modular stages for easy assembly and testing whilst also allowing future modifications to accommodate the required CCDs, electronics and optics.

Ferrusca, D.; Castillo, E.; Velázquez de la Rosa, M.; García-Vargas, M. L.; Zamorano, J.; Gil de Paz, A.; Gallego, J.; Carrasco, E.; Vílchez, J. M.; Sánchez-Moreno, F. M.

2013-05-01

291

Flexible cryogenic thermosyphon  

NASA Astrophysics Data System (ADS)

Cryocooler and pulse tubes have been increasingly used in small and large scale cryogenic systems including the superconducting magnet systems as heat sinks to attain and keep the required temperatures. Designing the thermal link between the mechanical refrigerator and the system may present a challenge due to the mechanical stresses developed during the cool-down of the assembled systems. Also, the cross section may be too bulky for metallic conductors for given thermal specifications. In this paper, a thermosysphon with a flexible fluid link between the evaporator and condenser is presented. The working fluid used in preliminary testing is nitrogen. The results of the initial testing of the flexible thermosyphon are presented.

Celik, Dogan; Painter, Thomas

2012-06-01

292

Cryogenic support member  

DOEpatents

A cryogenic support member is comprised of a non-metallic rod having a depression in at least one end and a metallic end connection assembled to the rod. The metallic end connection comprises a metallic plug which conforms to the shape and is disposed in the depression and a metallic sleeve is disposed over the rod and plug. The plug and the sleeve are shrink-fitted to the depression in the rod to form a connection good in compression, tension and bending.

Niemann, Ralph C. (Downers Grove, IL); Gonczy, John D. (Oak Lawn, IL); Nicol, Thomas H. (Aurora, IL)

1987-01-01

293

Biological Applications of Cryogenic Detectors  

SciTech Connect

High energy resolution and broadband efficiency are enabling the use of cryogenic detectors in biological research. Two areas where they have found initial application are X-ray absorption spectroscopy (XAS) and time-of-flight mass spectrometry (TOF-MS). In synchrotron-based fluorescence-detected XAS cryogenic detectors are used to examine the role of metals in biological systems by measuring their oxidation states and ligand symmetries. In time-of-flight mass spectrometry cryogenic detectors increase the sensitivity for biomolecule detection and identification for masses above {approx}50 kDa, and thus enable TOF-MS on large protein complexes or even entire viruses. More recently, cryogenic detectors have been proposed as optical sensors for fluorescence signals from biomarkers. We discuss the potential for cryogenic detectors in biological research, as well as the challenges the technology faces.

Friedrich, S

2003-12-03

294

Biological applications of cryogenic detectors  

NASA Astrophysics Data System (ADS)

High energy resolution and broadband efficiency enable the use of cryogenic detectors in biological research. Two areas where they have found initial application are X-ray absorption spectroscopy (XAS) and time-of-flight mass spectrometry (TOF-MS). In synchrotron-based fluorescence-detected XAS cryogenic detectors are used to examine the role of metals in biological systems by measuring their oxidation states and ligand symmetries. In TOF-MS cryogenic detectors increase the sensitivity for biomolecule detection and identification for masses above ~50kDa, and thus enable TOF-MS on large protein complexes or even entire viruses. More recently, cryogenic detectors have been proposed as optical sensors for fluorescence signals from biomarkers. We discuss the potential for cryogenic detectors in biological research, as well as the challenges the technology faces.

Friedrich, Stephan

2004-03-01

295

Mass spectrometry with cryogenic detectors  

NASA Astrophysics Data System (ADS)

Cryogenic detectors have recently been applied for the first time as ion detectors in time-of-flight mass spectrometry (TOF-MS). Because of their energy sensitivity cryogenic detectors are expected to have near 100% efficiency even for very large, slow-moving molecules, in contrast to microchannel plates whose efficiency drops considerably at large mass. Thus, cryogenic detectors could contribute to extending the mass range accessible by TOF-MS and help improving detection limits. In addition, the energy resolution provided by cryogenic detectors can be used for charge discrimination and studies of ion fragmentation, ion-detector interaction, and internal energies of large molecular ions. Cryogenic detectors could therefore prove to be a valuable diagnostic tool in TOF-MS. Here I summarize the results of recent demonstration experiments.

Frank, M.

2000-04-01

296

Cryogenic gas processing  

SciTech Connect

Higher boiling constituents are separated from a normally gaseous feed mixture, predominating in lower boiling constituents and containing significant amounts of such higher boiling constituents, such as natural gas by fractionally distilling a feed mixture having a temperature substantially below atmospheric temperature at a pressure substantially above atmospheric pressure at which temperature and pressure the feed mixture comprises both vapor and liquid phases to produce a first vapor phase substantially enriched in lower boiling constituents and a first liquid phase substantially enriched in higher boiling constituents, expanding at least a part of the first vapor phase to reduce the pressure and temperature and produce an expanded fluid stream comprising a second vapor phase and a second liquid phase, separating the second vapor phase from the second liquid phase, recycling the second liquid phase to the fractional distillation step as a reflux, recovering the second vapor phase as a product and recovering the first liquid phase as a product. In another embodiment, at least a part of the feed mixture is expanded prior to fractional distillation. In other embodiments, the feed mixture is separated into a vapor phase and a liquid phase and at least a part of the vapor phase is expanded and/or the feed mixture is first cooled by indirect heat exchange with the second vapor phase prior to recovery of the latter as a product.

Perez, E.P.

1984-04-24

297

Two-feed distillation: Same-composition feeds with different enthalpies  

SciTech Connect

Additional separation can be achieved in flash distillation by separating the liquid feed into two parts, vaporizing only one part, and feeding these (now) two feeds to the top and bottom of a column. The driving force for the additional separation is the difference in chemical potential between liquid and vapor feeds with the same composition. This idea of using two feeds with the same composition but different enthalpies (herein called two-enthalpy feed) is applied to stripping and enriching columns and fractional distillation. Two-enthalpy-feed distillation, a new method for using waste heat effectively, should be useful in heat-integrated plants. When an ordinary distillation column has a two-phase feed, the use of two-enthalpy feed increases separation (same N and L/D), or decreases the number of stages (same L/D, x{sub D}, and x{sub B}), or decreases the reflux ratio (same N, x{sub D}, and x{sub B}). The two-enthalpy-feed system has a lower minimum reflux ratio than ordinary distillation with a two-phase feed. For other types of feed, two-enthalpy-feed distillation requires either less energy or energy at a less extreme temperature (i.e., lower temperature for reboilers or higher temperature for condensers) than ordinary distillation. Examples are presented for constant relative volatilities, hydrocarbon systems, and ethanol-water.

Wankat, P.C.; Kessler, D.P. [Purdue Univ., West Lafayette, IN (United States). School of Chemical Engineering

1993-12-01

298

Heavy oil distillation system  

SciTech Connect

A method for increasing the amount of volatiles produced and decreasing the amount of coke produced from a fixed amount of a vacuum reduced crude from a vacuum distillation tower is described comprising: (a) feeding the vacuum reduced crude from the vacuum distillation tower directly into a coker combination tower; (b) coking a residuum stripped of volatiles generating coke drum vapor; (c) feeding the coke drum vapor into the coker combination tower in contact with and in direct countercurrent heat exchange relationship with the vacuum reduced crude in the coker combination tower whereby some of the coke drum vapor is absorbed by the vacuum-reduced crude generating a coker combination tower residuum; (d) feeding the coker combination tower residuum into a resid flash down tower maintained at a pressure below the pressure in the coker combination tower; (e) fractionating the coker combination tower residuum in flash down tower into a vapor stream and a liquid stream comprising a residuum stripped of volatiles; (f) feeding the residuum stripped of volatiles to a delayed coke drum and coking the resdiuum stripped of volatiles as provided in step (b); condensing the fractionated vapor stream.

Heaney, W.F.; Nitsch, A.R.

1988-04-12

299

Qutrit magic state distillation  

NASA Astrophysics Data System (ADS)

Magic state distillation (MSD) is a purification protocol that plays an important role in fault-tolerant quantum computation. Repeated iteration of the steps of an MSD protocol generates pure single non-stabilizer states, or magic states, from multiple copies of a mixed resource state using stabilizer operations only. Thus mixed resource states promote the stabilizer operations to full universality. MSD was introduced for qubit-based quantum computation, but little has been known concerning MSD in higher-dimensional qudit-based computation. Here, we describe a general approach for studying MSD in higher dimensions. We use it to investigate the features of a qutrit MSD protocol based on the five-qutrit stabilizer code. We show that this protocol distils non-stabilizer magic states, and identify two types of states that are attractors of this iteration map. Finally, we show how these states may be converted, via stabilizer circuits alone, into a state suitable for state-injected implementation of a non-Clifford phase gate, enabling non-Clifford unitary computation.

Anwar, Hussain; Campbell, Earl T.; Browne, Dan E.

2012-06-01

300

The Cryogenic Test Bed experiments: Cryogenic heat pipe flight experiment CRYOHP (STS53). Cryogenic two phase flight experiment CRYOTP (STS62). Cryogenic flexible diode flight experiment CRYOFD  

Microsoft Academic Search

This paper presents an overview of the Cryogenic Test Bed (CTB) experiments including experiment results, integration techniques used, and lessons learned during integration, test and flight phases of the Cryogenic Heat Pipe Flight Experiment (STS-53) and the Cryogenic Two Phase Flight Experiment (OAST-2, STS-62). We will also discuss the Cryogenic Flexible Diode Heat Pipe (CRYOFD) experiment which will fly in

Lee Thienel; Chuck Stouffer

1995-01-01

301

Vacuum Distillation of Americium Metal.  

National Technical Information Service (NTIS)

High-purity americium metal has been distilled in multigram quantities from a plutonium-americium alloy. The procedure consisted of a two-stage vacuum distillation carried out at 1200 exp 0 C and 10 exp -6 torr pressure. Four batches of americium metal we...

J. W. Berry J. B. Knighton C. A. Nannie

1982-01-01

302

Present status of solar distillation  

Microsoft Academic Search

In this communication an attempt has been made to review, in brief, work on solar distillation, its present status in the world today and its future perspective. The review also includes water sources, water demand, availability of potable water and purification methods including the state of art and historical background. The classification of distillation units has been done on the

G. N. Tiwari; H. N. Singh; Rajesh Tripathi

2003-01-01

303

Distillation Apparatuses Using Household Items  

Microsoft Academic Search

A simple apparatus to demonstrate distillation principles can be very difficult to build without the specialty glassware found in chemistry laboratories. We have built inexpensive but effective distillation apparatuses from equipment that can be easily purchased at local department, grocery, or hardware stores. In one apparatus, colored water is heated to boiling and the condensed vapors drip into another container.

Danielle R. D. Campanizzi; Brenda Mason; Christine K. F. Hermann

1999-01-01

304

LUX Cryogenics and Circulation  

NASA Astrophysics Data System (ADS)

LUX is a new dark matter direct detection experiment being carried out at the Sanford Underground Research Facility, at the renewed Homestake mine in Lead, SD. The detector's large size supports effective internal shielding from natural radioactivity of the surrounding materials and environment. The LUX detector consists of a cylindrical vessel containing 350 kg of liquid xenon (LXe) cooled down and maintained at 175-K operating temperature using a novel cryogenic system. We report the efficiency of our thermosyphon-based cooling system, as well as the efficiency of a unique internal heat exchanger with standard gas phase purification using a heated getter, which allows for very high flow purification without requiring large cooling power. Such systems are required for multi-ton scale up.

Bradley, Adam

2012-10-01

305

Nanodielectrics for Cryogenic Applications  

SciTech Connect

In this paper we report the recent advances in nanodielectrics that were developed and tested for cryogenic dielectric applications. The systems studied are composed of nanometer size particles. Particles were produced using either an ex-situ or in-situ technique. It is observed that there are clear differences in the structural properties of materials produced using these two approaches. Either no significant degradation or improvement in the electrical insulation properties were observed for ex-situ nano-particle samples processed with an ultrasonic processor and in-situ nano-particle samples. Nanodielectrics have the potential to be tailored with better thermal and mechanical properties without losing their electrical insulation characteristics.

Tuncer, Enis [ORNL; Sauers, Isidor [ORNL; James, David Randy [ORNL; Ellis, Alvin R [ORNL; Pace, Marshall O [ORNL; More, Karren [Oak Ridge National Laboratory (ORNL); Sathyamurthy, Srivatsan [University of Tennessee, Knoxville (UTK); Woodward, Jonathan [ORNL; Rondinone, Adam Justin [ORNL

2009-01-01

306

Cryogenic cooler apparatus  

DOEpatents

A Malone-type final stage for utilization in a Stirling cycle cryogenic cooler apparatus includes a displacer slidable within a vessel. .sup.4 He, .sup.3 He, or a mixture thereof is made to flow in a pulsating unidirectional manner through a regenerator in the displacer by utilization of check valves in separate fluid channels. Stacked copper screen members extend through the channels and through a second static thermodynamic medium within the displacer to provide efficient lateral heat exchange and enable cooling to temperatures in the range of 3-4 K. Another embodiment utilizes sintered copper particles in the regenerator. Also described is a final stage that has a non-thermally conducting displacer having passages with check valves for directing fluid past a regenerator formed in the surrounding vessel.

Wheatley, John C. (Del Mar, CA); Paulson, Douglas N. (Del Mar, CA); Allen, Paul C. (Sunnyvale, CA)

1983-01-01

307

Cryogenic nuclear gyroscope  

SciTech Connect

A cryogenic nuclear gyroscope is described that is comprised of a cylinder of niobium cooled within a helium cryostat so as to be superconducting and to provide a trapped, substantially homogeneous magnetic field, a helium-3 sample contained within a spherical pyrex cell having nuclei possessing a net magnetic moment, coils provided to polarize the sample to provide that net magnetic moment, and a SQUID magnetometer coupled to the sample by a pick-up coil of a transformer and frequency sensitive means coupled to the SQUID to detect changes in the precession of the nuclear moments of the sample caused by rotation of the gyroscope about an axis parallel to the direction of the homogeneous magnetic field. A superconducting lead shield isolates the helium-3 sample from external magnetic fields.

Gallop, J.C.; Potts, S.P.

1980-09-30

308

27 CFR 24.216 - Distilling material.  

Code of Federal Regulations, 2013 CFR

...material, using any quantity of water desired to facilitate fermentation or distillation. No sugar may be added in the production...material. Distillates containing aldehydes may be used in the fermentation of wine to be used as distilling material. Lees,...

2013-04-01

309

Argon SDC detector cryogenic design.  

National Technical Information Service (NTIS)

A first cut at designing the cryogenic systems is resented. The point design or sample design presented includes flow-rate calculations, piping sizes, dewar elevations, etc. In summary, the analysis shows argon cooling is ample even with relatively small ...

D. S. Slack

1991-01-01

310

Cryogenic Foam Insulation: Abstracted Publications.  

National Technical Information Service (NTIS)

A group of documents were chosen and abstracted which contain information on the properties of foam materials and on the use of foams as thermal insulation at cryogenic temperatures. The properties include thermal properties, mechanical properties, and co...

F. R. Williamson

1977-01-01

311

Cryogenic Temperature Control and Measurement.  

National Technical Information Service (NTIS)

A review is given of some of the many control, measurement, and regulation techniques for cryogenic temperatures, applying liquid coolants (LN2, LHe) and the equipment developed for their realization, such as pressure, coolant level, and temperature contr...

H. J. Forth

1977-01-01

312

Simulation of the Tetrahydrofuran Dehydration Process by Extractive Distillation in Aspen Plus  

Microsoft Academic Search

The aim of this work is to simulate and analyze an extractive distillation process (extractive distillation and recovery columns) for the separation of Tetrahydrofuran(THF)-Water azeotropic mixture using Aspen Plus® and Aspen Split simulators. Calculation of vapor liquid equilibrium of Tetrahydrofuran-Water- Entrainer system was done using the NRTL model, which binary interaction parameters were regressed using experimental data. A methodology for

P. Gómez; I. Gil

313

PREPARATION OF ULTRA-PURE SUCCINONITRILE BY COUNTERCURRENT DISTILLATION FOR CRYSTAL GROWTH  

Microsoft Academic Search

We developed the purification method to produce ultra-pure succinonitrile by multiple countercurrent distillations. The distillation column used was 25?mm in diameter and 110?cm in the packed height with Heli-Pak® packing (0·05” × 0·10” × 0·10”, packing factor+ 960). Typical operational conditions of each stage are as follows: condenser temperature 65 °C, reboiler temperature 160 °C, head pressure 50?m Torr or

YOUN-WOO LEE; RAMAGOPAL ANANTH; WILLIAM N. GILL

1996-01-01

314

Rheological Properties and Composition of Some Vacuum Distillates Derived from Indian Crudes  

Microsoft Academic Search

Three vacuum distillates boiling range 400°C–530°C derived from Bakrola, Dholka, and PY-3 crudes of Gujarat region (India) were subjected to urea adduction to isolate n-paraffin components from them. The deparaffinized base oils obtained after removal of n-paraffin components from the distillate fractions were further fractionated into various hydrocarbon-type constituents viz iso + cyclo paraffins, aromatics, and polar components by column

S. P. Nautiyal; H. U. Khan; K. P. Bhatt; K. M. Agrawal

2008-01-01

315

Low-order dynamic models for ideal multicomponent distillation processes using nonlinear wave propagation theory  

Microsoft Academic Search

A new approach to the development of low-order dynamic models for multicomponent distillation processes is presented. This approach makes direct use of well-known spatio-temporal pattern formation phenomena also termed as nonlinear wave propagation. It takes into account the typical features of multicomponent systems, i.e. coexistence of different constant pattern waves within a single section of a distillation column and the

Achim Kienle

2000-01-01

316

Make the most of distillation test runs  

SciTech Connect

Test runs for distillation columns can provide data that pinpoint plant problems and revamp opportunities, as well as define base line operations for statistical process control, and equipment efficiencies for process development work. In addition, they can serve as the basis for performance-guarantee validation, and pay-for-performance contracts. The test run measures three key factors -- temperature, pressure, and composition -- to define the state of streams. These measurements then allow a checking of material and heat balances. This article covers the purposes, required planning and preparation, data validation, execution, and coordination required to yield a useful test run. The authors also will show these principles applied to two actual test-run cases -- one that was a failure and one a success. They will illustrate the relative importance of the steps involved, and the uses and abuses of the data gathered.

Hanson, D.W.; Golden, S.W.; Martin, G.R.

1996-02-01

317

A decomposition method for synthesizing complex column configurations using tray-by-tray GDP models  

Microsoft Academic Search

This paper describes an optimization procedure for the synthesis of complex distillation configurations. A superstructure based on the Reversible Distillation Sequence Model (RDSM) is proposed embedding all possible alternative designs using tray-by-tray models. Generalize disjunctive programming (GDP) is used to model the superstructure. Each column section of the superstructure is modeled using rigorous MESH equations. Due to the large size

Mariana Barttfeld; P??o A Aguirre; Ignacio E. Grossmann

2004-01-01

318

Zirconium and hafnium tetrachloride separation by extractive distillation with molten zinc chloride lead chloride solvent  

SciTech Connect

In an extractive distillation method for separating hafniuim tetrachloride from zirconium tetrachloride of the type wherein a mixture of zirconium and hafnium tetrachlorides is introduced into an extractive distillation column, which extractive distillation column has a reboiler connected at the bottom and a reflux condenser connected at the top and wherein a molten salt solvent is circulated into the reflux condenser and through the column to provide a liquid phase, and wherein molten salt solvent containing zirconium tetrachloride is taken from the reboiler and run through a stripper to remove zirconium tetrachloride product from the molten salt solvent and the stripped molten salt solvent is returned to the reflux condenser and hafnium tetrachloride enriched vapor is taken as product from the reflux condenser, the improvement is described comprising: the molten salt having a composition of at least 30 mole percent zinc chloride and at least 10 mole percent of lead chloride.

McLaughlin, D.F.; Stoltz, R.A.

1988-04-12

319

Latest developments in cryogenic safety  

NASA Astrophysics Data System (ADS)

The Cryogenic Safety Manual, sponsored by the British Cryogenics Council, was published over 10 years ago. A new updated version is now available. Some general aspects of cryogenic safety are highlighted, and attention is drawn to some of the more unusual hazardous situations. An awareness of the physical properties of the cryogenic fluids being dealt with is important in directing attention to hazardous situations which may arise. Because of this, the more important properties of the cryogenic fluids are given, such as molecular weight, boiling point and freezing point. From these properties, hazardous situations can be deduced. There are hidden dangers that are not always easy to spot. Some of the unexpected hazards, most of which have led to deaths, are: asphyxiation (anoxia), frost bites and hypothermia, explosions, and combustion. The aim of this publication is to help bring about increased safety in the production and use of cryogenic products through a deeper appreciation of the scientific, technological and administrative steps which must be made if accidents, some fatal, are to be voided in the future.

Webster, T. J.

1983-03-01

320

Understand the limitations of air/water testing of distillation equipment  

SciTech Connect

Distillation continues to be a unit operation of major importance--and a dynamic area for technical development. The designs of trays and packings are rapidly evolving, and the application of equipment also is changing. As chemical processes are pushed to become more efficient and lower cost, a general reduction in the traditional values for equipment safety factors are being seen. The net results is that one now has a greater need for a more thorough and fundamental understanding of distillation equipment. One technique to improve the understanding of distillation equipment is air/water testing. Such testing of distillation trays has become very common, and air/water test results for packed columns also are being reported. In this article, the authors will provide some guidance on how to assess the validity of such tests to industrial applications. In addition, they will discuss several possible approaches to test--and develop confidence in--the design of distillation equipment.

Bennett, D.L.; Ludwig, K.A. (Air Products and Chemicals, Inc., Allentown, PA (United States))

1994-04-01

321

Technical and economic study of ethanol distillation from low-temperature sources. Final report, 23 June 1981-22 November 1982  

Microsoft Academic Search

The objectives of this project are to: (1) investigate the thermodynamics, mass transport, column contact efficiencies, and other operating characteristics of a distillation column operated with COâ carrier gas and with water absorption to remove alcohol vapor from recirculated COâ, to facilitate operation at lower temperatures; (2) modify the column to operate under a wide range of COâ flow rates,

Johnson

1983-01-01

322

Low energy distillation systems  

SciTech Connect

Much work, aimed at improvements in the manufacture and recovery of ethyl alcohol, is currently being conducted in connection with the production of substitute liquid fuels; e.g., gasohol. A primary consideration all schemes for producing substitute liquid fuels lies in the energy consumed to produce the fuels. By energy re-use, pressure cascading and waste heat recovery, the expenditure of energy in distillation (alcohol recovery) can be greatly reduced. Such energy savings have been industrially demonstrated in three systems described in this paper. For high grade industrial ethanol production, a steam consumption of 3.0 to 4.2 Kg/liter (25 to 35 lb/US gallon) of 100/sup 0/ G.L. alcohol is realized. For motor fuel grade anhydrous alcohol, the steam consumption is 1.8 to 2.5 Kg/liter (15 to 20 lb/US gallon) of 99.5/sup 0/ G.L. alcohol, and for hydrous motor fuel grade alcohol, the steam consumption is 1.2 to 1.4 Kg/liter (10 to 12 lb/US gallon) of 96/sup 0/ G.L. alcohol.

Katzen, R.; Ackley, W.R.; Moon, G.D. Jr.; Meesick, J.R.; Brush, B.F.; Kaupisch, K.F.

1980-01-01

323

Separation of n-propanol from allyl alcohol by extractive distillation  

SciTech Connect

This patent describes a method for recovering n-propanol from a mixture of n-propanol and allyl alcohol which comprises distilling a mixture of n-propanol and allyl alcohol in a rectification column in the presence of about one part of extractive agent per part of n-propanol-allyl alocohol mixture, recovering n-propanol as overhead product, obtaining the allyl alcohol and the extractive agent from the stillpot, separating the allyl alchohol from the extractive agent by distillation in another rectification column, wherein the extractive agent comprises at least one member of the group consisting of acetamide, N,N-dimethylacetamide, adiponitrile, dimethylformamide, dimethylsulfoxide and sulfolane.

Berg, L.; Vosburgh, M.G.

1986-07-22

324

Cryogenic Permanent Magnet Undulators  

SciTech Connect

For an in-vacuum undulator operated at small gaps the permanent magnet material needs to be highly resistant to possible electron beam exposure. At room temperature, one generally uses Sm{sub 2}Co{sub 17} or high coercivity NdFeB magnets at the expense of a limited field performance. In a cryogenic permanent magnet undulator (CPMU), at a temperature of around 150 K, any NdFeB grade reveals a coercivity large enough to be radiation resistant. In particular, very high remanence NdFeB material can be used to build undulators with enhanced field and X-ray brilliance at high photon energy provided that the pre-baking of the undulator above 100 deg. C can be eliminated. The ESRF has developed a full scale 2 m long CPMU with a period of 18 mm. This prototype has been in operation on the ID6 test beamline since January 2008. A significant effort was put into the characterization of NdFeB material at low temperature, the development of dedicated magnetic measurement systems and cooling methods. The measured heat budget with beam is found to be larger than expected without compromising the smooth operation of the device. Leading on from this first experience, new CPMUs are currently being considered for the upgrade of the ESRF.

Chavanne, J.; Lebec, G.; Penel, C.; Revol, F. [European Synchrotron Radiation Facility, B.P. 220, 38043 Grenoble Cedex 9 (France); Kitegi, C. [Synchrotron SOLEIL-L'Orme des Merisiers Saint-Aubin-BP 48 91192 GIF-sur-YVETTE (France)

2010-06-23

325

Cryogenic Neutron Spectrometer Development  

SciTech Connect

Cryogenic microcalorimeter detectors operating at temperatures around {approx}0.1 K have been developed for the last two decades, driven mostly by the need for ultra-high energy resolution (<0.1%) in X-ray astrophysics and dark matter searches [1]. The Advanced Detector Group at Lawrence Livermore National Laboratory has developed different cryogenic detector technologies for applications ranging from X-ray astrophysics to nuclear science and non-proliferation. In particular, we have adapted cryogenic detector technologies for ultra-high energy resolution gamma-spectroscopy [2] and, more recently, fast-neutron spectroscopy [3]. Microcalorimeters are essentially ultra-sensitive thermometers that measure the energy of the radiation from the increase in temperature upon absorption. They consist of a sensitive superconducting thermometer operated at the transition between its superconducting and its normal state, where its resistance changes very rapidly with temperature such that even the minute energies deposited by single radiation quanta are sufficient to be detectable with high precision. The energy resolution of microcalorimeters is fundamentally limited by thermal fluctuations to {Delta}E{sub FWHM} {approx} 2.355 (k{sub B}T{sup 2}C{sub abs}){sup 1/2}, and thus allows an energy below 1 keV for neutron spectrometers for an operating temperature of T {approx} 0.1 K . The {Delta}E{sub FWHM} does not depend on the energy of the incident photon or particle. This expression is equivalent to the familiar (F{var_epsilon}E{sub {gamma}}){sup 1/2} considering that an absorber at temperature T contains a total energy C{sub abs}T, and the associated fluctuation are due to variations in uncorrelated (F=1) phonons ({var_epsilon} = k{sub B}T) dominated by the background energy C{sub abs}T >> E{gamma}. The rationale behind developing a cryogenic neutron spectrometer is the very high energy resolution combined with the high efficiency. Additionally, the response function is simple and the instrument is transportable. We are currently developing a fast neutron spectrometer with 0.1% energy resolution at 1 MeV neutron energy with an efficiency of > 1%. Our fast-neutron spectrometers use boron-based and {sup 6}LiF absorber crystals with Mo/Cu thermistors readout. They have achieved an energy resolution of 5.5 keV FWHM for 2.79 MeV deposited in {sup 10}B by thermal neutron capture (fig. 1), and 46 keV FWHM for fast (MeV) neutrons absorbed in {sup 6}LiF (fig. 2). Since the energy resolution does not depend on the neutron energy, we expect a similar energy resolution for MeV neutron energies. The response function is given simply by the cross section of the capture reaction, offset from zero by the Q-value of the capture reaction. This allows straightforward discrimination against gamma-events, most of which deposit less that Q{sub 6Li} = 4.79 MeV in the {sup 6}LiF absorber, and easy deconvolution of the neutron spectrum, since there is only a single capture reaction in {sup 6}Li and the spectrum is not affected by edge effects or geometric broadening. The current challenge for microcalorimeters is their necessarily small effective pixel area, {approx}1cm{sup 3} for neutron spectrometer pixels, and their slow decay time, {approx}10ms for neutron spectrometers. The pixel size is limited by the requirement for low Cabs for high energy resolution; the decay time is set by the intrinsically weak thermal coupling between materials at low temperatures. Both issues can be addressed by fabricating large detector arrays. This will enable high-precision neutron spectrometry with high statistics, such as simulated for Pu analysis in fig 3.

Niedermayr, T; Hau, I D; Friedrich, S; Burger, A; Roy, U N; Bell, Z W

2006-03-08

326

Eliminating foaming in hydrocarbon distillations  

SciTech Connect

A method for eliminating foam in hydrocarbon distillation systems where the foaming is caused by an ionic surface-active substance is involved. Foam is eliminated by the addition of an effective amount of a surfactant electrolytically opposite to the surface-active material already in the system. The surfactant added and the surface-active substance already in the system complex to form a non-foaming combination, allowing distillation to proceed without foaming.

Veatch, F.C.; Orrell, D.D.

1984-09-25

327

Vacuum distillation of americium metal  

Microsoft Academic Search

High-purity americium metal has been distilled in multigram quantities from a plutonium-americium alloy. The procedure consisted of a two-stage vacuum distillation carried out at 1200°C and 10⁻⁶ torr pressure. Four batches of americium metal were produced ranging in weight from 13.3 grams to 54.1 grams. The purity of the americium product ranged from 99.27 to 99.79%.

J. W. Berry; J. B. Knighton; C. A. Nannie

1982-01-01

328

Distillation process using microchannel technology  

DOEpatents

The disclosed invention relates to a distillation process for separating two or more components having different volatilities from a liquid mixture containing the components. The process employs microchannel technology for effecting the distillation and is particularly suitable for conducting difficult separations, such as the separation of ethane from ethylene, wherein the individual components are characterized by having volatilities that are very close to one another.

Tonkovich, Anna Lee (Dublin, OH); Simmons, Wayne W. (Dublin, OH); Silva, Laura J. (Dublin, OH); Qiu, Dongming (Carbondale, IL); Perry, Steven T. (Galloway, OH); Yuschak, Thomas (Dublin, OH); Hickey, Thomas P. (Dublin, OH); Arora, Ravi (Dublin, OH); Smith, Amanda (Galloway, OH); Litt, Robert Dwayne (Westerville, OH); Neagle, Paul (Westerville, OH)

2009-11-03

329

Distillation control: For productivity and energy conservation  

Microsoft Academic Search

The introduction of new types of distillation control equipment has necessitated the publication of this second edition. Thermodynamic principles, flow ratios, composition control, and azeotropic distillation are among the topics covered. It includes bibliographies, computer programs suitable for distillation calculations, and a subject index. Contents Distillation fundamentals. Control system structure. Complex processes. Optimization. Appendices. Index.

Skinskey

1984-01-01

330

Azeotropic Distillation: A Review of Mathematical Models  

Microsoft Academic Search

Azeotropic distillation as an early and important special distillation process is commonly used in laboratory and industry. It can be used for separating the mixture with close boiling point or forming azeotrope. This paper tries to provide a review on azeotropic distillation for general readers, focusing on entrainer selection and mathematical models. Since the 1950s, along with extractive distillation, azeotropic

Jianwei Li; Zhigang Lei; Zhongwei Ding; Chengyue Li; Biaohua Chen

2005-01-01

331

Optimal Distillation Sequencing Using a Genetic Algorithm  

Microsoft Academic Search

Optimal distillation sequencing is a method for obtaining the best structure of multicomponent separation processes. Due to the significant contribution of the distillation sequences to the capital and operating costs for the whole chemical process, the development of a systematic framework that will select the optimal distillation sequences becomes an important research issue. Since distillation sequencing is a combinatorial problem,

P. Piumsomboon

2001-01-01

332

Latest developments in cryogenic safety  

SciTech Connect

The Cryogenic Safety Manual, sponsored by the British Cryogenics Council, was published over 10 years ago. A new updated version is now available. Some general aspects of cryogenic safety are highlighted, and attention is drawn to some of the more unusual hazardous situations. An awareness of the physical properties of the cryogenic fluids being dealt with is important in directing attention to hazardous situations which may arise. Because of this, the more important properties of the cryogenic fluids are given, such as molecular weight, boiling point and freezing point. From these properties, hazardous situations can be deduced. There are hidden dangers that are not always easy to spot. Some of the unexpected hazards, most of which have led to deaths, are: asphyxiation (anoxia), frost bites and hypothermia, explosions, and combustion. The aim of this publication is to help bring about increased safety in the production and use of crygenic products through a deeper appreciation of the scientific, technological and administrative steps which must be made if accidents, some fatal, are to be voided in the future.

Webster, T.J.

1983-03-01

333

Elastomeric Seals and Materials at Cryogenic Temperatures.  

National Technical Information Service (NTIS)

This research deals with low temperature investigations of elastomeric polymers, with particular emphasis on their use as seals at cryogenic temperatures. The present report starts with a study of correlations between physical properties and cryogenic sea...

D. H. Weitzel R. F. Robbins P. R. Ludtke Y. Ohori

1964-01-01

334

Latest developments in cryogenic safety  

NASA Astrophysics Data System (ADS)

The Cryogenic Safety Manual, published under the auspices of the British Cryogenics Council, is summarized. Since an awareness of the physical properties of the cryogenic fluids being dealt with is considered important in directing attention to hazardous situations which may arise, the manual lists the more important properties, such as molecular weight, boiling point, and freezing point. Since hydrogen and helium are very light, the possibility arises of explosive mixtures being formed at high points in buildings. Since argon is unexpectedly heavy, its removal requires suction rather than blowing. It is also pointed out that the use of inert liquid nitrogen can lead to the creation of a noninert atmosphere which supports combustion because it contains oxygen. Attention is also given to the danger of asphyxiation posed by the growing use of inert gases.

Webster, T.

1982-05-01

335

Advances in Cryogenic Avalanche Detectors  

NASA Astrophysics Data System (ADS)

Cryogenic Avalanche Detectors (CRADs) are referred to as a new class of noble-gas detectors operated at cryogenic temperatures with electron avalanching performed directly in the detection medium, the latter being in gaseous, liquid or two-phase (liquid-gas) state. Electron avalanching is provided by Micro-Pattern Gas Detector (MPGD) multipliers, in particular GEMs and THGEMs, operated at cryogenic temperatures in dense noble gases. The final goal for this kind of detectors is the development of large-volume detectors of ultimate sensitivity for rare-event experiments and medical applications, such as coherent neutrino-nucleus scattering, direct dark matter search, astrophysical (solar and supernova) neutrino detection experiments and Positron Emission Tomography technique. This review is the first attempt to summarize the results on CRAD performances obtained by different groups. A brief overview of the available CRAD concepts is also given and the most remarkable CRAD physics effects are discussed.

Buzulutskov, A.

2012-02-01

336

Irrigation of a condensation column with lateral collection  

SciTech Connect

The calculation of optimum operating conditions for the fractional distillation of coal tars is described. Temperature, reflux and irrigation regimes for a 48 plate condensation column with lateral collection have been estimated, the feed stock beam separated into a light fraction, a phenol fraction, naphthalene, wash fraction and anthracene fraction.

Zykov, D.D.; Kulagina, L.A.

1982-01-01

337

Graphically find theoretical trays and minimum reflux for Complex multicomponent distillation  

SciTech Connect

The article describes a procedure which provides the means for making the preliminary design of a distillation column and for analyzing column design and performance. Its development follows the steps of Hengstebeck's derivation for a simple, single-feed fractionator. For each feed, all the light nonkeys introduced end up in the rising vapor, and all the heavy nonkeys in the descending liquid. A useful set of guidelines on the applications of the procedure is presented.

Kister, H.Z.

1985-05-13

338

Feasibility of application of Thayer method to crude oil distillation  

SciTech Connect

The purpose of this report is to present the results of an evaluation of Victor R. Thayer's invention: ''Process and Apparatus for reducing the Energy Required to Separate Liquids by Distillation'', applied to crude oil distillation. In brief, Thayer claims that given a side draw-off pump-around on a distillation column for energy conservation, there would be a significant cost advantage by using on-tray heat exchange rather than external exchange. Preliminary cost estimates were made: external case, $1,091,000 +- 15%; on-tray case, $882,200 +- 20%; both values falling within the estimated uncertainity limits. Therefore, and coupled with much greated annual maintenance costs, a significant cost advantage of the on-tray system was not verified. The primary conclusion of the evaluation was that, in our opinion, the Thayer method will not be used for retrofit of crude oil distillation units, and probably will not be used in the design of new crude units. 12 refs.

Prengle, H.W. Jr.; Althaus, Y.E.

1987-07-31

339

Design and Synthesis Procedure for Homogeneous and Heterogeneous Azeotropic Distillations: Annual Report for Period March 1, 1986 to February 29, 1987.  

National Technical Information Service (NTIS)

The column sequencing problem for heterogeneous azeotropic distillation is investigated. It is shown that residue curve maps play an important role in interpreting the behavior of these systems. Classes of residue curve maps which give rise to feasible co...

M. F. Doherty

1986-01-01

340

Influence parameters in the ozonation of phenol wastewater treatment using bubble column reactor under continuous circulation  

Microsoft Academic Search

The ozonation of phenol wastewater treatment system has been investigated with effective mass transfer between gas and liquid phase in a bubble column reactor. The designed bubble column reactor was investigated for increasing the rate of mass transfer of ozone, the rate of oxidation of phenol in the solution, the solubility and decomposition rate of ozone in the distilled water

Manickam Matheswaran; Il Shik Moon

2009-01-01

341

Antioxidant activity of phytochemicals from dried distillers grain oil  

Technology Transfer Automated Retrieval System (TEKTRAN)

A distillate was obtained by molecular distillation of oil extracted from distiller’s dried grains (DDG). The dried distiller’s grains distillate (DDGD) contained phytosterols, steryl ferulates, tocopherols, tocotrienols, and carotenoids. DDGD was tested for its impact on the oxidative stability in...

342

Optimal protocols for nonlocality distillation  

SciTech Connect

Forster et al. recently showed that weak nonlocality can be amplified by giving the first protocol that distills a class of nonlocal boxes (NLBs) [Phys. Rev. Lett. 102, 120401 (2009)] We first show that their protocol is optimal among all nonadaptive protocols. We next consider adaptive protocols. We show that the depth-2 protocol of Allcock et al. [Phys. Rev. A 80, 062107 (2009)] performs better than previously known adaptive depth-2 protocols for all symmetric NLBs. We present a depth-3 protocol that extends the known region of distillable NLBs. We give examples of NLBs for which each of the Forster et al., the Allcock et al., and our protocols perform best. The understanding we develop is that there is no single optimal protocol for NLB distillation. The choice of which protocol to use depends on the noise parameters for the NLB.

Hoeyer, Peter; Rashid, Jibran [Department of Computer Science, University of Calgary, 2500 University Drive N.W., Calgary, Alberta, 2N 1N4 (Canada)

2010-10-15

343

Ilc Cryogenic Systems Reference Design  

NASA Astrophysics Data System (ADS)

A Global Design Effort (GDE) began in 2005 to study a TeV scale electron-positron linear accelerator based on superconducting radio-frequency (RF) technology, called the International Linear Collider (ILC). In early 2007, the design effort culminated in a reference design for the ILC, closely based on the earlier TESLA design. The ILC will consist of two 250 GeV linacs, which provide positron-electron collisions for high energy physics research. The particle beams will be accelerated to their final energy in superconducting niobium RF cavities operating at 2 kelvin. At a length of about 12 km each, the main linacs will be the largest cryogenic systems in the ILC. Positron and electron sources, damping rings, and beam delivery systems will also have a large number and variety of other superconducting RF cavities and magnets, which require cooling at liquid helium temperatures. Ten large cryogenic plants with 2 kelvin refrigeration are envisioned to cool the main linacs and the electron and positron sources. Three smaller cryogenic plants will cool the damping rings and beam delivery system components predominately at 4.5 K. This paper describes the cryogenic systems concepts for the ILC.

Peterson, T. J.; Geynisman, M.; Klebaner, A.; Parma, V.; Tavian, L.; Theilacker, J.

2008-03-01

344

Electrical insulation at cryogenic temperatures  

Microsoft Academic Search

Summary form only given, as follows. In order to reduce the size and mass of portable, high power electrical systems cryogenic cooling is being studied. This allows an increase in efficiency in the generator, high current conductors, and power electronic switches, resulting in smaller conductors, lower resistive losses, and more efficient switching. However, the effects of the low temperatures (ranging

L. B. Gordon; T. Hardy; L. Origgi; P. Vu

1996-01-01

345

ILC cryogenic systems reference design  

SciTech Connect

A Global Design Effort (GDE) began in 2005 to study a TeV scale electron-positron linear accelerator based on superconducting radio-frequency (RF) technology, called the International Linear Collider (ILC). In early 2007, the design effort culminated in a reference design for the ILC, closely based on the earlier TESLA design. The ILC will consist of two 250 GeV linacs, which provide positron-electron collisions for high energy physics research. The particle beams will be accelerated to their final energy in superconducting niobium RF cavities operating at 2 kelvin. At a length of about 12 km each, the main linacs will be the largest cryogenic systems in the ILC. Positron and electron sources, damping rings, and beam delivery systems will also have a large number and variety of other superconducting RF cavities and magnets, which require cooling at liquid helium temperatures. Ten large cryogenic plants with 2 kelvin refrigeration are envisioned to cool the main linacs and the electron and positron sources. Three smaller cryogenic plants will cool the damping rings and beam delivery system components predominately at 4.5 K. This paper describes the cryogenic systems concepts for the ILC.

Peterson, T.J.; Geynisman, M.; Klebaner, A.; Theilacker, J.; /Fermilab; Parma, V.; Tavian, L.; /CERN

2008-01-01

346

HF Cryogenic Low Noise Amplifier  

Microsoft Academic Search

AL\\/DTA and IN\\/SNEC had developed a demonstrator of an RF cryogenic LNA in order to improve the links budget of remote sensing earth station. Working in X band, the cooled LNA allows to reduce efficiently the size of the antennas. So, this solution offers a cheaper alternative to the actual technology used in this area. This demonstrator operates at 80

T. Trollier; A. Ravex; D. Butin

2004-01-01

347

Survey of cryogenic semiconductor devices  

SciTech Connect

Improved reliability and electronic performance can be achieved in a system operated at cryogenic temperatures because of the reduction in mechanical insult and in disruptive effects of thermal energy on electronic devices. Continuing discoveries of new superconductors with ever increasing values of T{sub c} above that of liquid nitrogen temperature (LNT) have provided incentive for developing semiconductor electronic systems that may also operate in the superconductor`s liquid nitrogen bath. Because of the interest in high-temperature superconductor (HTS) devices, liquid nitrogen is the cryogen of choice and LNT is the temperature on which this review is focused. The purpose of this survey is to locate and assemble published information comparing the room temperature (298 K), performance of commercially available conventional and hybrid semiconductor device with their performance at LNT (77K), to help establish their candidacy as cryogenic electronic devices specifically for use at LNT. The approach to gathering information for this survey included the following activities. Periodicals and proceedings were searched for information on the behavior of semiconductor devices at LNT. Telephone calls were made to representatives of semiconductor industries, to semiconductor subcontractors, to university faculty members prominent for their research in the area of cryogenic semiconductors, and to representatives of the National Aeronautics and Space Administration (NASA) and NASA subcontractors. The sources and contacts are listed with their responses in the introduction, and a list of references appears at the end of the survey.

Talarico, L.J.; McKeever, J.W.

1996-04-01

348

CRYOGENIC MACHINING OF KEVLAR COMPOSITES  

Microsoft Academic Search

Previous attempts to machine Kevlar aramid fibre reinforced plastics (KFRP) with conventional cutting tools have proven to be extremely difficult. This has somewhat restricted the material's usage, often negating the advantages of its high strength to weight ratio and fatigue tolerance. The present paper describes a novel technique of machining KFRP under cryogenic conditions with remarkable results compared to those

D. Bhattacharyya; M. N. Allen; S. J. Mander

1993-01-01

349

Cryogenic aerosol cleaning of photomasks  

Microsoft Academic Search

This paper describes the mechanism and cleaning results of a dry cleaning technology using CO2 cryogenic aerosols. The cleaning mechanism relies on momentum transfer from the aerosol particles to overcome the force of adhesion of the contaminant particles on the surface. Particle removal is possible without degradation or etching of underlying film or the need for drying with IPA as

S. Banerjee; C. C. Lin; S. Su; H. F. Chung; W. Brandt; K. Tang

2005-01-01

350

Solar distillation of sea water  

SciTech Connect

Indian coastal and fishing villages suffer from scarcity of potable water. Solar distillation could provide a solution to this problem by adopting the following criteria: (1) Integration of distillation and storage systems with the house design. (2) Public supply of sea water and a public drain pipe system to periodically drain away the concentrated brine. (3) Harvest and store rain water to tide over cloudy rainy periods. In India there has been a thrust towards centralized non-conventional energy systems. Decentralized non-conventional energy devices and centralized service support units may offer a better solution. 1 fig.

Subramanyam, S. (Kakatiya Institute of Technology and Science, Warangal (India))

1989-01-01

351

Distilling entanglement from arbitrary resources  

NASA Astrophysics Data System (ADS)

We obtain the general formula for the optimal rate at which singlets can be distilled from any given noisy and arbitrarily correlated entanglement resource by means of local operations and classical communication (LOCC). Our formula, obtained by employing the quantum information spectrum method, reduces to that derived by Devetak and Winter [Proc. R. Soc. London, Ser. A 461, 207 (2005)], in the special case of an independent and identically distributed resource. The proofs rely on a one-shot version of the so-called ``hashing bound,'' which, in turn, provides bounds on the one-shot distillable entanglement under general LOCC.

Buscemi, Francesco; Datta, Nilanjana

2010-10-01

352

Homoazeotropic distillation of maximum azeotropes in a batch rectifier with continuous entrainer feeding I. Feasibility studies  

Microsoft Academic Search

Our former method for the assessment of the feasibility of extractive distillation in a batch rectifier was extended for the investigation of the separation of maximum azeotropes. The method is based on the calculation of the still path and possible composition profiles of the column sections. The sequence of the separation steps was determined, then limiting values and the influence

P. Lang; G. Modla; B. Benadda; Z. Lelkes

2000-01-01

353

Design and optimization of recycle policies for multicomponent azeotropic distillation processes with bifurcation analysis  

Microsoft Academic Search

A novel design method for finding cost-optimized recycle policies for multicomponent azeotropic distillation processes is presented. The design task is formulated in form of a nonlinear optimization problem with the aim of minimizing the energy consumption of the process. The minimum energy demand of each column is determined using the rectification body method (RBM). Closure of the mass balance around

Stefan Brüggemann; Wolfgang Marquardt

2004-01-01

354

Experimental and modeling studies on a homogeneous reactive distillation system for dimethyl carbonate synthesis by transesterification  

Microsoft Academic Search

This paper gives a comprehensive study on dimethyl carbonate synthesis by transesterification reaction of methanol with ethylene carbonate (EC), resulted from CO2 and ethylene epoxide, co-producing useful ethylene glycol (EG). The reaction is reversible with an EC equilibrium conversion of about 80%. The reactive distillation column is an ideal reactor to realize a completion conversion of EC. A novel experimental

Yun-Jin Fang; Wen-De Xiao

2004-01-01

355

The Equivalence of Non-Interacting Control System Design Methods in Distillation  

Microsoft Academic Search

Singular Value Analysis has been used to design structural compensators for the material balance control scheme in distillation. The control system obtained is similar to (1) column profile control, (2) implicit decoupling, (3) modal control, (4) output decoupling and, under some conditions, (5) extensive variable control. The material balance control scheme does not require an input compensator because the right

B. W. Bequette; T. F. Edgar

1986-01-01

356

Optimum design of Petlyuk and divided-wall distillation systems using a shortcut model  

Microsoft Academic Search

An optimization approach for fully thermally coupled distillation systems for the separation of ternary mixtures is presented. The thermally coupled schemes considered here can be implemented in the form of the original Petlyuk arrangement (with an external prefractionator) or the modified Kaibel arrangement (in the form of a divided-wall column). The approach uses a shortcut design method that allows the

Nelly Ramírez-Corona; Arturo Jiménez-Gutiérrez; Angel Castro-Agüero; Vicente Rico-Ramírez

2010-01-01

357

Invariant rectifying-stripping curves for targeting minimum energy and feed location in distillation  

Microsoft Academic Search

Invariant rectifying-stripping (IRS) curves are proposed that are independent of the feed location and operating reflux of the distillation column for a given separation problem. IRS curves represent the enthalpy surpluses and deficits in the rectifying and stripping sections, respectively, as a function of temperature for all possible values of reflux and reboil. The IRS curves provide a new representation

Santanu Bandyopadhyay; Ranjan K. Malik; Uday V. Shenoy

1999-01-01

358

Integration and testing of a cogenerating concentrating solar collector with advanced alcohol-distillation equipment  

Microsoft Academic Search

An advanced concept of vapor recompression of alcohol in a distillation column has been demonstrated. Its potential as a primary method separating alcohol from water lies in its operational simplicity, potential for automation, and low operating cost. Though it does use electrical power to drive the compressor, the benefits of using the heat of condensation to drive the reboiler warrant

W. Rogers; D. N. Borton

1983-01-01

359

Prediction of Temperature and Concentration Distributions of Distillation Sieve Trays by CFD  

Microsoft Academic Search

A three-dimensional two-fluid computational fluid dynamics (CFD) model is developed to predict concentration and temperature distributions on sieve trays of distillation columns and good simulation results are obtained. The dispersed gas phase and continuous liquid phase are modeled in the Eulerian framework as two interpenetrating phases with interphase momentum, heat and mass transfer. Closure models are developed for interphase transfer

Mahmood-Reza Rahimi; Rahbar Rahimi; Farhad Shahraki; Morteza Zivdar

2006-01-01

360

A cyclic operating policy for batch distillation–theory and practice  

Microsoft Academic Search

This paper sets out a cyclic operation policy for batch distillation with repeated filling and dumping of the reflux drum. The policy has several advantages compared to conventional schemes; it achieves the maximum attainable separation in the column; there is a minimal need for control and it is less sensitive to disturbances and therefore safer to operate. In this study,

Eva Sørensen

1999-01-01

361

EXTRACTIVE DISTILLATION BY SALT EFFECT  

Microsoft Academic Search

Extractive distillation employing a dissolved salt instead of a liquid third component as the separating agent is a promising but relatively neglected technique for achieving azeotropic and other difficult separations. In systems for which a soluble and effective salt can be found, major savings in both capital and energy costs are possible. The technical aspects of such processing are described

WILLIAM F. FURTER

1992-01-01

362

DISTILLERS GRAINS IN POULTRY DIETS  

Microsoft Academic Search

Anticipation of increased supplies of distiller's dried grains with solubles (DDGS) in the Midwest has rekindled the interest in utilization of this by-product in animal feeds. In the Midwest US, corn is the primary feed stock although other grains can be processed as well. With increasing numbers of chicken layers and a large turkey industry in the Midwest, use of

S. Noll; V. Stangeland; G. Speers; J. Brannon

363

OPPORTUNITIES FOR UTILIZING DISTILLERS GRAINS  

Technology Transfer Automated Retrieval System (TEKTRAN)

The fuel ethanol industry is currently experiencing unprecedented growth. In conjunction with this expansion, the quantity of distillers grains produced over time has grown in parallel. This industry has continually evolved, and technological innovations and process changes have been implemented tha...

364

Corrosion inhibition for distillation apparatus  

DOEpatents

Tower material corrosion in an atmospheric or sub-atmospheric distillation tower in a coal liquefaction process is reduced or eliminated by subjecting chloride-containing tray contents to an appropriate ion-exchange resin to remove chloride from such tray contents materials.

Baumert, Kenneth L. (Emmaus, PA); Sagues, Alberto A. (Lexington, KY); Davis, Burtron H. (Georgetown, KY); Schweighardt, Frank K. (Upper Macungie, PA)

1985-01-01

365

Heat recovery in distillation process  

Microsoft Academic Search

A distillation process for recovering concentrated ethanol from an aqueous fermentate comprises fractionation of components of the aqueous fermentate under reduced pressure with vapor recompression and recovery of waste heat in a manner which obviates the need for substantial external sources of heat to operate the fractionation apparatus. The process includes a preliminary enrichment of the fermentate to separate volatile

1982-01-01

366

Membrane distillation: theory and experiments  

Microsoft Academic Search

A theoretical approach is presented that describes membrane distillation processes due to the simultaneous action (in a proactive or in a counteractive way) of temperature and concentration differences through porous hydrophobic membranes. The model developed emphasizes the importance of the boundary layers, shows the existence of a coupling term between the two thermodynamic forces acting on the system, and permits

Paz Godino; Luis Peña; Juan I. Mengual

1996-01-01

367

Distillation modeling for a uranium refining process.  

National Technical Information Service (NTIS)

As part of the spent fuel treatment program at Argonne National Laboratory, a vacuum distillation process is being employed for the recovery of uranium following an electrorefining process. Distillation of a salt electrolyte, containing a eutectic mixture...

B. R. Westphal

1996-01-01

368

Hydrodynamics of Distillation Trays: Review and Simulations.  

National Technical Information Service (NTIS)

In this report the physical modeling of gas-liquid flows has been studied and flow simulations at distillation trays have been performed. In the literature review the flow behavior on the distillation plate, measurement methods and experimental results by...

T. Koiranen

2001-01-01

369

Volatile Components of Milk Fat Steam Distillates Identified by Gas Chromatography and Mass Spectrometry[1] and [2  

Microsoft Academic Search

Yacuum steam distillates of buttcroil, fresh raw cream, fresh pasteurized cream, and pasteurized stored cream were ana- lyzed by packed column and open-tubular colunm gas chromatography in conjunc- tion with ms~ss spectrometry. High-tem- perature (210 C) distillations of different butteroils yielded over 120 volatile com- pounds. Identification (or tentative identi- fication) of more than 100 of these com- pounds was

T. J. Siek; R. C. Lindsay

1968-01-01

370

UTILIZATION OF ACTIVATED ZEOLITE AS MOLECULAR SIEVE IN CHROMATOGRAPHIC COLUMN FOR SEPARATION OF COAL TAR COMPOUNDS Pemanfaatan Zeolit Aktif sebagai Molecular Sieve untuk Pengisi Kolom Kromatografi pada Pemisahan Komponen Tar Batu Bara  

Microsoft Academic Search

Application of activated zeolite (ZAA) as molecular sieve to separate compounds of coal tar from vaccum fractional distillation, have been done. The size of zeolite was 10-20 mesh and used as solid phase in column chromatography with length of 30 cm. The first step of the research was coal pyrolisis and the product (tar) was distillated by fractional column and

Dwi Retno; Nurotul Wahidiyah; Bambang Setiaji; Iqmal Tahir

371

Multiple steady states in heterogeneous azeotropic distillation  

Microsoft Academic Search

In this article, the authors study multiple steady states in ternary heterogeneous azeotropic distillation. They show that in the case of infinite reflux and an infinite number of trays, 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 nonmonotonically along the continuation path of

Nikolaos Bekiaris; George A. Meski; Manfred Morari

1996-01-01

372

Multiple Steady States in Homogeneous Azeotropic Distillation  

Microsoft Academic Search

In this article we study multiple steady states in ternary homogeneous azeotropic distillation. We show that in the case of infinite reflux and an infinite number of trays, multiple steady states exist when the distillate flow varies non-monotonically along the continuation path of the bifurcation diagram with the distillate flow as the bifurcation parameter. We derive a necessary and sufficient

Nikolaos BekiarisGeorge; George A. Meski; Cristian M. Radu; Manfred Morari

1993-01-01

373

New Glassware for Small-Scale Distillation  

Microsoft Academic Search

Distillation of less than a ml of sample can be accomplished with a jacketed Hickman still. The jacket allows positioning of a coolant such as dry ice\\/acetone at the site of desired condensation. A jacketed distillation head will accommodate samples up to a volume of 3 ml. Distillate is easily removed with a Pasteur pipette. Details of the glassware design

Richard J. Petroski; Hugh J. Bowe

1996-01-01

374

Cryogenic processes and equipment - 1984; Proceedings of the Fifth Intersociety Cryogenics Symposium, New Orleans, LA, December 9-14, 1984  

Microsoft Academic Search

The topics of cryogenic processes for LNG and EOR, cryogenic refrigerators, components for cryogenic systems, liquid hydrogen as a fuel, cryogenic processes and equipment for large systems, and cryogenic thermodynamics and heat transfer are discussed. The papers include analysis of process efficiency for baseload LNG production, process efficiency considerations for nitrogen rejection units, design and performance analysis of gas sorption

P. J. Kerney; N. Chatterjee; D. B. Cranwford; M. El-Masri

1984-01-01

375

Multiple steady state and instability in distillation. Implications for operation and control  

SciTech Connect

The fact that distillation columns, even in the ideal binary case, may display multiple steady states and unstable operating points has only recently been recognized. This article addresses some implications of these phenomena for the operation and control of distillation columns. Under manual operation, the multiplicity and instability will result in ability to reach separations corresponding to unstable operating points and may furthermore cause abrupt changes and hysteresis in operating conditions. It is shown that an unstable operating point may be stabilized by feedback control of a single product composition or tray temperature (one-point control). The steady-state multiplicity does, in this case, not represent any severe limitation in operation, but if the control is not sufficient tight, the column may settle in sustained oscillations (stable limit cycle). Finally, the impact of open-loop instability on the achievable closed-loop performance with both product compositions under feedback control is discussed.

Jacobsen, E.W. [Royal Inst. of Tech., Stockholm (Sweden); Skogestad, S. [Univ. of Trondheim (Norway)

1995-12-01

376

Plasma Column Generation Study.  

National Technical Information Service (NTIS)

A study has been conducted on methods of producing unconfined plasma columns of length one to twenty meters in air at atmospheric pressure. Turbulent combustion gas jet and flammable liquid jets were considered for producing the plasma columns, which were...

P. S. Masser W. Cramer R. E. Petersen A. J. Hoehn E. K. Parks

1969-01-01

377

Advanced cryogenic tank development status  

NASA Astrophysics Data System (ADS)

Significant advances have been made in the development of materials, structures, and manufacturing technologies for the next generation of cryogenic propellant tanks under the auspices of a joint U.S. Air Force/NASA sponsored advanced development program. This paper summarizes the achievements of this three-year program, particularly in the evolution and properties of Weldalite 049, net shape component technology, Al-Li welding technology, and efficient manufacturing concepts. Results of a recent mechanical property characterization of a full-scale integrally stiffened barrel panel extrusion are presented, as well as plans for an additional weld process optimization program using response surface design of experiment techniques. A further discussion is given to the status of hardware completed for the Advanced Manufacturing Development Center and Martin Marietta's commitment to the integration of these technologies into the production of low-cost, light-weight cryogenic propellant tanks.

Braun, G. F.; Tack, W. T.; Scholz, E. F.

1993-06-01

378

Relaxation phenomena in cryogenic electrolytes  

NASA Astrophysics Data System (ADS)

Proposed is a scenario for the development of observed relaxation phenomena in a cryogenic electrolyte with the structure of ``liquid hydrogen + injected ions.'' Ions of one sign are generated in the bulk of liquid hydrogen in the presence of external field E? by a stationary radioactive source of +/- ions at the bottom of a vessel. After accumulation near the free surface of the liquid with a finite density ns the ions can break its stability producing a pulse of ion current to the collector located above the liquid surface. The outlined process is periodically repeated. Its period contains information on the ion mobility and, which is most interesting, on dissociation (association) processes occurring in a system of charged particles placed in an external field. The cryogenic problem is a good model for dissociation in the presence of external field occurring in normal electrolytes without any external ion sources.

Shikin, V.; Chikina, I.; Nazin, S.

2013-06-01

379

Feasible separation modes for various reactive distillation systems  

SciTech Connect

The feasibility of steady states of continuous reactive distillation processes is discussed by applying the theory of static analysis (SA). The generality of this approach is proved by applying several industrial examples, all of which have different reaction schemes and thermodynamical properties. For each example process, the entire feed composition region is divided into several subregions, each of which has similar characteristics for the product composition and the column structure. The information derived by this analysis can be used effectively for the selection of the desirable feed composition and column configurations. The results of various examples indicate that the SA is a very convenient tool that provides an answer to the question of feasibility and provides hints for an early stage of design.

Giessler, S.; Danilov, R.Y.; Pisarenko, R.Y.; Serafimov, L.A.; Hasebe, S.; Hashimoto, I.

1999-10-01

380

Advances in cryogenic engineering. Volume 29  

SciTech Connect

Applications of superconductivity are discussed, taking into account the thermal performance of the MFTF magnets, the design and testing of a large bore superconducting magnet test facility, the development of a 12-tesla multifilamentary Nb3Sn magnet, a superconducting magnet for solid NMR studies, advanced applications of superconductors, transition and recovery of a cryogenically stable superconductor, and finite-difference modeling of the cryostability of helium II cooled conductor packs. Other topics explored are related to resource availability, heat exchangers, heat transfer to He I, liquid nitrogen, heat transfer in He II, refrigeration for superconducting and cryopump systems, refrigeration of cryogenic systems, refrigeration and liquefaction, dilution and magnetic refrigeration, cryocoolers, refrigeration for space applications, cryogenic applications, cryogenic instrumentation and data acquisition, and properties of fluids. Attention is given to biomedical applications of cryogenics in China, long-term cryogen storage in space, and a passive orbital disconnect strut.

Fast, R.W.

1984-01-01

381

Steels for cryogenic power engineering  

Microsoft Academic Search

1.The mechanical properties of the investigated steels at normal and cryogenic temperatures improve when their aluminum content increases to 10%. Further alloying with aluminum causes some impairement of the plastic and ductile properties; this is connected with the formation of a-phase in the structure of the steels.2.Magnetic permeability is practically independent of the temperature in the range 293–4°K because of

B. S. Ermakov; A. Ya. Nikolaich; V. A. Oparin

1986-01-01

382

Cryogenic moderator simulations : confronting reality.  

SciTech Connect

The Intense Pulsed Neutron Source (IPNS) at Argonne National Laboratory is a spallation neutron source dedicated to materials research. Its three cryogenic methane moderators provide twelve neutron beams to fourteen instruments and test facilities. This report concerns ongoing activities for benchmarking our Monte Carlo model of the IPNS neutron generation system. This paper concentrates on the techniques (both experimental and calculational) used in such benchmarking activities.

Iverson, E. B.

1999-01-06

383

Cryomechanism: a cryogenic rotating actuator  

NASA Astrophysics Data System (ADS)

Fifteen years ago, CEA started the development of cryogenic rotating actuators for the astrophysical infrared camera (VISIR) that is set on the Very Large Telescope (VLT). At the time of the VISIR first light in 2004, 10 cryogenic rotating actuators, also known as "CryoMechanisms" (CM), were present in the instrument. Today VISIR is still operating and the CM that are actuated several times a day, have no reported failure up to now. In continuation of the VISIR project, CEA undertook space qualification tests with the aim of making the CM compatible with space missions. Relying on this background, a smaller model of the mechanism has been built and tested at cryogenic temperatures. Today, the cryomechanisms are selected for the ESA/EUCLID [1] space mission. The qualification program will run throughout 2014. This paper first describes the VISIR's baseline specification, the CM design and its operation principle. Then, the upgrades for the space constrains are shown and the qualification plan with respect to vibrations, thermal cycling and life testing campaigns is given. Some results of the tests carried out on a qualification model are addressed. At end, the design improvements for the EUCLID project are presented and a summary of the CM capabilities is highlighted.

Barriere, J.-C.; Berthé, M.; Carty, M.; Duboué, B.; Fontignie, J.; Leboeuf, D.; Martignac, J.; Cara, C.; Charon, P.; Durand, G. A.; Bachet, D.

2013-09-01

384

Usaf Space Sensing Cryogenic Considerations  

NASA Astrophysics Data System (ADS)

Infrared (IR) space sensing missions of the future depend upon low mass components and highly capable imaging technologies. Limitations in visible imaging due to the earth's shadow drive the use of IR surveillance methods for a wide variety of applications for Intelligence, Surveillance, and Reconnaissance (ISR), Ballistic Missile Defense (BMD) applications, and almost certainly in Space Situational Awareness (SSA) and Operationally Responsive Space (ORS) missions. Utilization of IR sensors greatly expands and improves mission capabilities including target and target behavioral discrimination. Background IR emissions and electronic noise that is inherently present in Focal Plane Arrays (FPAs) and surveillance optics bench designs prevents their use unless they are cooled to cryogenic temperatures. This paper describes the role of cryogenic coolers as an enabling technology for generic ISR and BMD missions and provides ISR and BMD mission and requirement planners with a brief glimpse of this critical technology implementation potential. The interaction between cryogenic refrigeration component performance and the IR sensor optics and FPA can be seen as not only mission enabling but also as mission performance enhancing when the refrigeration system is considered as part of an overall optimization problem.

Roush, F.

2010-04-01

385

The evolution of cryogenic safety at Fermilab  

SciTech Connect

Over the past twenty-five years, Fermilab has been involved in cryogenic technology as it relates to pursuing experimentation in high energy physics. The Laboratory has instituted a strong cryogenic safety program and has maintained a very positive safety record. The solid commitment of management and the cryogenic community to incorporating safety into the system life cycle has led to policies that set requirements and help establish consistency for the purchase and installation of equipment and the safety analysis and documentation.

Stanek, R.; Kilmer, J.

1992-12-01

386

Eddy Current Damper for Cryogenic Applications  

NASA Astrophysics Data System (ADS)

This presentation considers the following topics: the need for cryogenic energy absorption, high speed damper characteristics, gearbox characteristics, composite assembly characteristics, performance tests, simulation models.

Starin, Scott; Crosno, Fred

2002-09-01

387

Reactive distillation and kinetic azeotropy  

SciTech Connect

The general pattern of trajectories of equilibrium distillation with nonequilibrium reversible reaction in the liquid phase is discussed. In some cases there is a continuous line of singular points belonging to different ratios of the evaporation rate and the reaction rate. These points are the kinetic azeotropes. When this line has a common intersection point with the hypersurface of chemical equilibrium, then the evaporation ratio approaches zero at the intersection point and the equilibrium reactive azeotrope, described by Barbosa and Doherty, exists there. The continuation of the kinetic azeotropy line after crossing the equilibrium surface is not a set of singular points. The stationary point of reactive distillation can be controlled, along the line of kinetic azeotropy, by the evaporation ratio.

Rev, E. (Technical Univ. of Budapest (Hungary). Dept. of Chemical Engineering)

1994-09-01

388

Experimental distillation of quantum nonlocality.  

PubMed

We report the first experimental demonstration of distillation of quantum nonlocality, confirming the recent theoretical protocol [Phys. Rev. Lett. 102, 120401 (2009)]. Quantum nonlocality is described by a correlation box with binary inputs and outputs, and the nonlocal boxes are realized through appropriate measurements on polarization entangled photon pairs. We demonstrate that nonlocality is amplified by connecting two nonlocal boxes into a composite one through local operations and four-photon measurements. PMID:23952373

Zu, C; Deng, D-L; Hou, P-Y; Chang, X-Y; Wang, F; Duan, L-M

2013-08-02

389

An expert multivariable controller for distillation process control  

SciTech Connect

Recent advances in the field of Artificial Intelligence (AI) and the area of Expert Systems (ES) facilitate the encoding of symbolic reasoning and make possible the creation of control systems where algorithmic knowledge and human experience can interact, resulting in more efficient and reliable control systems. In the present study, a methodology to design control systems that provide safe and effective operation for multivariable processes during on-line closed loop control has been developed. This methodology has been implemented in a control system called Expert Multivariable Controller (EMC). The EMC determines and implements on-line the normal, abnormal (sensor failure and valve saturation) and constrained (process constraints) structures to be used under normal and abnormal operating conditions. This requires selecting controlled and manipulated variables, determining the level of operation, pairing controlled with manipulated variables, selecting controller types, and designing controllers. The structure and methodology of the EMC are generic and independent of the controlled process and the control theory used. The EMC has been implemented in ART using facts, frames, and rules. Its performance has been tested using linear and nonlinear dynamic models of two product distillation columns, as well as a three product sidestream distillation column. The successful application of the EMC to the control of these processes under a wide range of normal and abnormal operating conditions using diagonal as well as multivariable controller structures (IMC) demonstrates its effectiveness.

Tzouanas, V.K.

1989-01-01

390

Cryogenic optical systems and instruments II  

SciTech Connect

This book contains the proceedings of a conference of the Society for Optical Engineering. Topics covered are: Cryogenic optical systems considerations; Cryogrenic instruments and components; Design and performance of cryogenic dewars for space; and Supporting technology for crogenic systems and instruments.

Melugin, R.K.

1986-01-01

391

Cryogenic Electrical Insulation and its Advantage  

Microsoft Academic Search

This paper summarizes the cryogenic electrical insulation with polymers and its interesting features. At cryogenic temperature, polymers show high electric strength, extremely higher ac treeing inception voltage, low tandelta, no thermal and chemical degradation, no water tree degradation, very limited space charge injection and resulting high short-circuit treeing inception voltage, etc. Based on these features, we can call polymer at

Masayuki Nagao

2004-01-01

392

D0 Cryogenic Auto Dialing Alarm System  

Microsoft Academic Search

The Automatic Dialing system purchased by D0 is intended to help make the D0 cryogenic system operate unattended by cryogenic operating personnel. The auto dialer is completely programmable and is voice synthesized. The auto dialer was purchased with 32 bistable inputs, but is expandable to 64 bistable inputs with the purchase of more electronic cards at an approximate cost of

D. Markely

1992-01-01

393

Designs of pulsed power cryogenic transformers  

Microsoft Academic Search

The Westinghouse Electric Corporation has completed designs of three pulsed power cryogenic transformers of three pulsed power cryogenic transformers for the Los Alamos National Laboratory. These transformers will be configured to transfer their stored energy sequentially to an electro-magnetic launcher and form a three-stage power supply. The pulse transformers will act as two winding energy storage solenoids which provide a

S. K. Singh; C. J. Heyne; D. T. Hackowrth; E. J. Shestak; P. W. Eckels; J. D. Rogers

1988-01-01

394

Cryogenic spin testing of NASA's shuttle engines  

NASA Astrophysics Data System (ADS)

Spin testing of the Space Shuttle Main Engine (SSME) high-pressure turbopump rotors is described focusing on the SSME cryogenic spin test facility. Testing at full operating speed is predicated on achieving and maintaining a cryogenic rotor temperature. Rotors are driven to operational speeds after being chilled to - 195 C.

Maillar, Kenneth M.; Enos, Anthony; Gauthier, Robert

1992-12-01

395

D0 Cryogenic Auto Dialing Alarm System.  

National Technical Information Service (NTIS)

The Automatic Dialing system purchased by D0 is intended to help make the D0 cryogenic system operate unattended by cryogenic operating personnel. The auto dialer is completely programmable and is voice synthesized. The auto dialer was purchased with 32 b...

D. Markely

1992-01-01

396

Advances in cryogenic engineering: Vol. 31  

Microsoft Academic Search

This volume comprises the proceedings of the 1985 Cryogenic Engineering Conference held August 12-16, 1985, in Cambridge, Massachusetts. The 151 included papers begin by discussing the applications of superconductivity in the following fields: the Superconducting Super Collider; superconducting magnetic energy storage; magnets for fusion and physics research; test facilities; cryogenic techniques; acoustic emission testing; and magnet stability. From there, the

1986-01-01

397

Advances in cryogenic engineering. Vol. 29  

Microsoft Academic Search

This volume contains 116 of the papers presented at the 1983 Cryogenic Engineering Conference held in Colorado. The latest work of the most advanced researchers in low-temperature technology is reviewed. Topics considered include resource availability (helium, LNG), applications of superconductivity (magnets for fusion and physics research, test facilities, components of electric power systems, electronics and RF structures, cryogenic techniques, magnet

1984-01-01

398

Space cryogenic system for SPICA mission  

Microsoft Academic Search

This paper describes that the feasibility of the next Japanese infrared astronomical SPICA mission is verified in thermal design by numerical analyses and developed technologies. In this advanced cryogenic mission, in order to cool the large primary mirror and focal plane instruments down to 4.5 K for 5 years or longer without cryogen, the mechanical cooling is employed with effective

Hiroyuki Sugita; Hiroki Nagai; Takao Nakagawa; Hiroshi Murakami; Toshio Matsumoto; Masahide Murakami; Katsuhiro Narasaki; Masayuki Hirabayashi

2004-01-01

399

Design concepts for the ASTROMAG cryogenic system  

Microsoft Academic Search

Described is a proposed cryogenic system used to cool the superconducting magnet for the Space Station based ASTROMAG Particle Astrophysics Facility. This 2-meter diameter superconducting magnet will be cooled using stored helium II. The paper presents a liquid helium storage concept which would permit cryogenic lifetimes of up to 3 years between refills. It is proposed that the superconducting coil

M. A. Green; S. Castles

1988-01-01

400

Design concepts for the ASTROMAG cryogenic system  

Microsoft Academic Search

Described is a proposed cryogenic system used to cool the superconducting magnet for the Space Station based ASTROMAG Particle Astrophysics Facility. This 2-meter diameter superconducting magnet will be cooled using stored helium II. The paper presents a liquid helium storage concept which would permit cryogenic lifetimes of up to 3 years between refills. It is proposed that the superconducting coil

M. A. Green; S. Castles

1987-01-01

401

Nanoinclusions in cryogenically quenched nanoemulsions.  

PubMed

Nanodroplets containing mixtures of silicone oil and squalene are dispersed in a simple aqueous surfactant solution, quenched in liquid ethane, and examined using cryogenic transmission electron microscopy (CTEM). Depending on the phase of ice that forms around the nanodroplets and on the composition of the oil mixture, nanoinclusions can be observed inside oil nanodroplets, independent of surfactant type. Our observations suggest that these nanoinclusions arise from nucleation of vapor cavities as the water freezes and expands while the oil remains liquid during the quench. PMID:22881456

Fryd, Michael M; Mason, Thomas G

2012-08-10

402

Synthesis of separation flowsheets for multicomponent azeotropic mixtures on the basis of the distillation theory. Presynthesis: prediction of feasible product compositions  

Microsoft Academic Search

A general approach based on the theory of distillation-trajectory tearing off is adopted in the synthesis of optimal separation\\u000a flowsheets for multicomponent azeotropic mixtures. The first stage of the synthesis—presynthesis—is considered, at which feasible\\u000a product compositions are predicted for the separation in a simple column, a two-feed column, and a column with a decanter.

F. B. Petlyuk; R. Yu. Danilov

2000-01-01

403

Process mechanisms in coking a distillate feedstock  

Microsoft Academic Search

1.The coking mechanism for distillate feedstocks has been studied in the example of an extract from a coker gas oil.2.In contrast to the coking of residual stocks, the coking of a distillated feedstock that is essentially asphaltene-free, within the limits of the process conditions investigated, brings about a continuous accumulation of asphaltenes in the residue.3.Another difference observed with distillate feedstock

G. D. Golubkova; E. V. Smidovich

1974-01-01

404

Distillation modeling for a uranium refining process  

Microsoft Academic Search

As part of the spent fuel treatment program at Argonne National Laboratory, a vacuum distillation process is being employed for the recovery of uranium following an electrorefining process. Distillation of a salt electrolyte, containing a eutectic mixture of lithium and potassium chlorides, from uranium is achieved by a simple batch operation and is termed {open_quotes}cathode processing{close_quotes}. The incremental distillation of

1996-01-01

405

Effects of water on steam rectification in a packed column  

Microsoft Academic Search

The effects of water on steam rectification, i.e., multi-stage saturated steam distillation, were investigated in a packed column. N-octane–p-xylene and 1,3,5-trimethylbenzene–1,2,4-trimethylbenzene were used as test systems. Both binary systems are nearly ideal systems and insoluble in water, thus the effects of water in steam rectification can be clearly and definitely revealed. Such unpolar organic liquid is named as “oil”. The

Qingli Qian; Hongxing Wang; Peng BAI; Guoqing Yuan

2011-01-01

406

Correlate the flooding of packed columns a new way  

Microsoft Academic Search

Packed-column pressure-drop and flooding-point prediction has received new attention recently. These publications, like most earlier ones, focus on gas-flow-induced pressure drop, and flooding due to liquid entrainment in the packing. A few years ago, some problems occurred when packing was applied in high-pressure distillation service, such as ethylene and propylene superfractionators. Apparently, the maximum liquid-through-put capacity was lower than predicted

1994-01-01

407

Cryogenic machining of Kevlar composites  

NASA Astrophysics Data System (ADS)

Previous attempts to machine Kevlar aramid fibre reinforced plastics (KFRP) with coventional cutting tools have proven to be extremely difficult. This has somewhat restricted the material's usage, often negating the advantages of its high strength-to-weight ratio and fatigue tolerance. The present paper describes a novel technique of machining KFRP under cryogenic conditions with remarkable results compared to those obtained at ambient temperatures. The investigation carried out with turning operation shows dramatic improvement of the tool performance and surface quality. The effects of various machining parameters such as workpiece temperature, cutting speed, and tool geometry on the machinability of KFRP are presented and analyzed. It appears that care is necessary to judge the tool life as the typical tool wear growth and surface finish or cutting force may produce contradictory results. It is also suggested that, for KFRP, surface finish of the machined workpiece is a very good criterion to determine the tool life. To aid the understanding of the machining mechanics, a microscopic investigation of the cutting zone while actually machining a testpiece at ambient and cryogenic temperatures is also reported.

Bhattacharyya, D.; Allen, M. N.; Mander, S. J.

408

Superconducting RF Systems and Cryogenics  

SciTech Connect

The subgroup on Supercondcuting RF Systems and Cryogenics was assigned the following tasks: (1) provide acceptable design recommendations for the accelerating structures and related RF and Cryogenics systems based on the parameters established by High Energy and Nuclear Physics needs (namely a final energy of 2.5 and 8 GeV at the end of the first and second stage, respectively, and the ability of accelerating simultaneously the 200{micro}A Nuclear Physics beam and the three bunches for High Energy Physics). (2) estimate the cost of such systems based on realistic, present day technology, with some assessment of future costs as technology and cavity manufacturing processes will improve. These tasks were carried out for the case of the original design which includes two racetracks of similar structure and with different energies, as well as for the more recent design of Amaldi and Coignet which is capable of reaching a center of mass energy of 15 GeV (alternate design). Design and cost estimates were done for a few cases of possible achievable gradients.

C. Benvenuti; P. Bernard; E. Chiaveri; E. Haebel; H. Lengeler; M. Minestrini; Joseph Bisognano; Isidoro Campisi; Christoph Leemann; R. Boni; U. Gambardella; G. Modestino; B Spataro; F. Tazzioli; H. Piel

1987-12-01

409

Challenges for Cryogenics at Iter  

NASA Astrophysics Data System (ADS)

Nuclear fusion of light nuclei is a promising option to provide clean, safe and cost competitive energy in the future. The ITER experimental reactor being designed by seven partners representing more than half of the world population will be assembled at Cadarache, South of France in the next decade. It is a thermonuclear fusion Tokamak that requires high magnetic fields to confine and stabilize the plasma. Cryogenic technology is extensively employed to achieve low-temperature conditions for the magnet and vacuum pumping systems. Efficient and reliable continuous operation shall be achieved despite unprecedented dynamic heat loads due to magnetic field variations and neutron production from the fusion reaction. Constraints and requirements of the largest superconducting Tokamak machine have been analyzed. Safety and technical risks have been initially assessed and proposals to mitigate the consequences analyzed. Industrial standards and components are being investigated to anticipate the requirements of reliable and efficient large scale energy production. After describing the basic features of ITER and its cryogenic system, we shall present the key design requirements, improvements, optimizations and challenges.

Serio, L.

2010-04-01

410

A new cryogenic diode thermometer  

NASA Astrophysics Data System (ADS)

While the introduction of yet another cryogenic diode thermometer is not earth shattering, a new diode thermometer, the DT-600 series, recently introduced by Lake Shore Cryotronics, possesses three features that make it unique among commercial diode thermometers. First, these diodes have been probed at the chip level, allowing for the availability of a bare chip thermometer matching a standard curve-an important feature in situations where real estate is at a premium (IR detectors), or where in-situ calibration is difficult. Second, the thermometry industry has assumed that interchangeability should be best at low temperatures. Thus, good interchangeability at room temperatures implies a very good interchangeability at cryogenic temperature, resulting in a premium priced sensor. The DT-600 series diode thermometer is available in an interchangeability band comparable to platinum RTDs with the added advantage of interchangeability to 2 K. Third, and most important, the DT-600 series diode does not exhibit an instability in the I-V characteristic in the 8 K to 20 K temperature range that is observed in other commercial diode thermometer devices [1]. This paper presents performance characteristics for the DT-600 series diode thermometer along with a comparison of I-V curves for this device and other commercial diode thermometers exhibiting an I-V instability. .

Courts, S. S.; Swinehart, P. R.; Yeager, C. J.

2002-05-01

411

CRYOPUMPING IN CRYOGENIC INSULATIONS FOR A REUSABLE LAUNCH VEHICLE1  

Microsoft Academic Search

Testing at cryogenic temperatures was performed to verify the material characteristics and manufacturing processes of reusable propellant tank cryogenic insulations for a Reusable Launch Vehicle (RLV). The unique test apparatus and test methods developed for the investigation of cryopumping in cryogenic insulations are described. Panel level test specimens with various types of cryogenic insulations were subjected to a specific thermal

Theodore F. Johnson; Erik S. Weiser; Brian W. Grimsley; Brian J. Jensen

412

Diabatic column optimization compared to isoforce columns  

Microsoft Academic Search

This paper analyzes and compares optimization results for simulated diabetic columns to theoretically derived optimization results from the isoforce method for the same system. The separation of ethanol and water is used to illustrate the two methods and bring out their common and special features. The results, which are presented in McCabe-Thiele diagrams, show partial compatibility between the methods. The

Erik Sauar; Ricardo Rivero; Signe Kjelstrup; Kristian M. Lien

1997-01-01

413

Neuro-estimator based GMC control of a batch reactive distillation.  

PubMed

In this paper, an artificial neural network (ANN)-based nonlinear control algorithm is proposed for a simulated batch reactive distillation (RD) column. In the homogeneously catalyzed reactive process, an esterification reaction takes place for the production of ethyl acetate. The fundamental model has been derived incorporating the reaction term in the model structure of the nonreactive distillation process. The process operation is simulated at the startup phase under total reflux conditions. The open-loop process dynamics is also addressed running the batch process at the production phase under partial reflux conditions. In this study, a neuro-estimator based generic model controller (GMC), which consists of an ANN-based state predictor and the GMC law, has been synthesized. Finally, this proposed control law has been tested on the representative batch reactive distillation comparing with a gain-scheduled proportional integral (GSPI) controller and with its ideal performance (ideal GMC). PMID:21334616

Prakash, K J Jithin; Patle, Dipesh S; Jana, Amiya K

2011-02-22

414

Multiple steady states in distillation: Effect of VL(L)E inaccuracies  

SciTech Connect

Output multiplicities in heterogeneous azeotropic distillation columns were studied. The accuracy of the thermodynamic description is a key factor that determines if multiplicities can be observed in numerical simulations. The descriptions used in the multiplicity-related literature are analyzed. The {infinity}/{infinity} analysis of Bekiaris et al. (1996) was used to check implications of inaccuracies in the reported thermodynamics on the existence of multiplicities in azeotropic distillation. On this basis, guidelines are derived concerning what features of thermodynamic descriptions need special attention for use in multiplicity prediction and simulation. secondly, numerical studies on output multiplicities in heterogeneous azeotropic distillation in the literature were compared to the {infinity}/{infinity} predictions wherever possible. The {infinity}/{infinity} analysis was used to derive the relations between the reported multiplicities and to identify the physical phenomena causing them.

Bekiaris, N.; Guettinger, T.E.; Morari, M.

2000-05-01

415

Modeling of column flotation  

Microsoft Academic Search

Many investigators believe that column flotation cells offer significant advantages over standard mechanical machines for the flotation of fine particles. However, because of their unique design and operation, conventional techniques for flotation cell scale-up and design cannot be applied to columns. In an attempt to help alleviate this problem, a population balance model based on first principles has been developed

G. H. Luttrell; G. T. Adel; R. H. Yoon

1987-01-01

416

Free fatty acid separation from vegetable oil deodorizer distillate using molecular distillation process  

Microsoft Academic Search

Distillates of the vegetable oil deodorization are composed of free fatty acids (FFA), sterols, tocopherols, sterol esters, hydrocarbons and breakdown products of fatty acids, aldehydes, ketones and acylglycerols. The content of free fatty acids in deodorizer distillates varies between 25 and 75%. Due to its high content, free fatty acid separation from deodorizer distillate is an important step to concentrate

P. F. Martins; V. M. Ito; C. B. Batistella; M. R. W. Maciel

2006-01-01

417

Modeling of column flotation  

SciTech Connect

Many investigators believe that column flotation cells offer significant advantages over standard mechanical machines for the flotation of fine particles. However, because of their unique design and operation, conventional techniques for flotation cell scale-up and design cannot be applied to columns. In an attempt to help alleviate this problem, a population balance model based on first principles has been developed for fine particle flotation in a column. Two different terms have been considered in the model, i.e., transport and rate. Transport terms, incorporating fluid flow and buoyancy, are used to describe the movement of air bubbles, unattached particles and bubble-particle aggregates along the length of the column. Rate terms, which describe the bubble-particle attachment process, have been derived from first principle considerations. Because the model is based on first principles, it can be useful for the design, control, optimization and scale-up of column flotation cells. 9 refs., 12 figs.

Luttrell, G.H.; Adel, G.T.; Yoon, R.H.

1987-01-01

418

JCE Feature Columns  

NASA Astrophysics Data System (ADS)

The Features area of JCE Online is now readily accessible through a single click from our home page. In the Features area each column is linked to its own home page. These column home pages also have links to them from the online Journal Table of Contents pages or from any article published as part of that feature column. Using these links you can easily find abstracts of additional articles that are related by topic. Of course, JCE Online+ subscribers are then just one click away from the entire article. Finding related articles is easy because each feature column "site" contains links to the online abstracts of all the articles that have appeared in the column. In addition, you can find the mission statement for the column and the email link to the column editor that I mentioned above. At the discretion of its editor, a feature column site may contain additional resources. As an example, the Chemical Information Instructor column edited by Arleen Somerville will have a periodically updated bibliography of resources for teaching and using chemical information. Due to the increase in the number of these resources available on the WWW, it only makes sense to publish this information online so that you can get to these resources with a simple click of the mouse. We expect that there will soon be additional information and resources at several other feature column sites. Following in the footsteps of the Chemical Information Instructor, up-to-date bibliographies and links to related online resources can be made available. We hope to extend the online component of our feature columns with moderated online discussion forums. If you have a suggestion for an online resource you would like to see included, let the feature editor or JCE Online (jceonline@chem.wisc.edu) know about it. JCE Internet Features JCE Internet also has several feature columns: Chemical Education Resource Shelf, Conceptual Questions and Challenge Problems, Equipment Buyers Guide, Hal's Picks, Mathcad in the Chemistry Curriculum, and WWW Site Review. These columns differ from the print feature columns in that they use the Internet as the publication medium. Doing so allows these features to include continually updated information, digital components, and links to other online resources. The Conceptual Questions and Challenge Problems feature of JCE Internet serves as a good example for the kinds of resources that you can expect to find in an online feature column. Like other columns it contains a mission statement that defines the role of the column. It includes a digital library of continually updated examples of conceptual questions and challenge problems. (As I write this we have just added several new questions to the library.) It also includes a list of links to related online resources, information for authors about how to write questions and problems, and information for teachers about how to use conceptual questions and challenge problems. Teaching with Technology home page at JCE Online. One-Stop Feature Shop The updated Feature area of JCE Online offers information about all JCE feature columns in one place. It gives you a quick and convenient way to access a group of articles in a particular subject area. It provides authors and readers with a good definition of the column and its mission. It complements the print feature columns with online resources. It provides up-to-date bibliographies for selected areas of interest. And last, but not least, it provides that email address you can use to send that message of appreciation to the feature editor for his or her contribution to JCE and the chemical education community.

Holmes, Jon L.

1999-05-01

419

Imaging of liquid distribution in reactive distillation packings with a new high-energy x-ray tomograph  

NASA Astrophysics Data System (ADS)

We describe a new, high-energy (420 kV), large-scale (0.45 m in diameter, 4 m in height) x-ray tomograph developed to investigate gas and liquid flow through fixed bed like absorption, distillation and reactive distillation columns. The first results obtained with this set-up on test objects (physical phantoms), such as a cylindrical container filled with water or a large diameter structured metallic packing, validate the technique as a quantitative tool for geometrical measurements. Very detailed two-dimensional (2D) and three-dimensional (3D) images of a 0.09 m diameter KATAPAK-SP 12, a reactive distillation packing, are presented. Quantitative information relative to liquid hold-up distribution may be obtained from tomographic imaging performed on an irrigated column packed with this element.

Toye, D.; Crine, M.; Marchot, P.

2005-11-01

420

Comparison of advanced distillation control methods. Second annual report  

SciTech Connect

Detailed dynamic simulations of three industrial distillation columns (a propylene/propane splitter, a xylene/toluene column, and a depropanizer) have been used to study the issue of configuration selection for diagonal PI dual composition controls. ATV identification with on-line detuning was used for tuning the diagonal PI composition controllers. Each configuration was evaluated with respect to steady-state RGA values, sensitivity to feed composition changes, and open loop dynamic performance. Each configuration was tuned using setpoint changes over a wider range of operation for robustness and tested for feed composition upsets. Overall, configuration selection was shown to have a dominant effect upon control performance. Configuration analysis tools (e.g., RGA, condition number, disturbance sensitivity), were found to reject configuration choices that are obviously poor choices, but were unable to critically differentiate between the remaining viable choices. Configuration selection guidelines are given although it is demonstrated that the most reliable configuration selection approach is based upon testing the viable configurations using dynamic column simulators.

NONE

1996-11-01

421

Extractive distillation of binary azeotropic mixtures  

Microsoft Academic Search

The conditions have been determined under which an azeotropic binary mixture can be separated by extractive distillation and\\u000a under which separation into almost pure components is impossible at any amount of the extracting agent. A general algorithm\\u000a is suggested for analysis of special manifolds in order to see whether extractive distillation is efficient.

L. A. Serafimov; A. K. Frolkova; D. I. Bushina

2008-01-01

422

Water Purification by Membrane Distillation Process  

Microsoft Academic Search

The demineralization of water by membrane distillation (MD) has been investigated. In the first stage of investigations the tap water or boiled tap water was employed as a feed, and the water recovery coefficient exceeding 75% was achieved. The obtained concentrate was supplied to the second stage of MD installation. The quality of distillate was stable and practically independent of

Marek Gryta

2006-01-01

423

Recycling of Waste Acetone by Fractional Distillation  

ERIC Educational Resources Information Center

Distillation is a ubiquitous technique in the undergraduate organic chemistry curriculum; the technique dates back to ca. 3500 B.C.E. With the emergence of green chemistry in the 1990s, the importance of emphasizing responsible waste management practices for future scientists is paramount. Combining the practice of distillation with the message…

Weires, Nicholas A.; Johnston, Aubrey; Warner, Don L.; McCormick, Michael M.; Hammond, Karen; McDougal, Owen M.

2011-01-01

424

Distillation of liquid fuels by thermogravimetry.  

National Technical Information Service (NTIS)

In this paper, design and operation of a custom-built thermogravimetric apparatus for the distillation of liquid fuels are reported. Using a sensitive balance with scale of 0.001 g and ASTM distillation glassware, several petroleum and petroleum-derived s...

H. Huang K. Wang S. Wang M. T. Klein W. H. Calkins

1996-01-01

425

Recycling of Waste Acetone by Fractional Distillation  

ERIC Educational Resources Information Center

|Distillation is a ubiquitous technique in the undergraduate organic chemistry curriculum; the technique dates back to ca. 3500 B.C.E. With the emergence of green chemistry in the 1990s, the importance of emphasizing responsible waste management practices for future scientists is paramount. Combining the practice of distillation with the message…

Weires, Nicholas A.; Johnston, Aubrey; Warner, Don L.; McCormick, Michael M.; Hammond, Karen; McDougal, Owen M.

2011-01-01

426

Heat transport in the membrane distillation process  

Microsoft Academic Search

Investigation of membrane distillation (MD) with a laminar flow of the streams in a module has been performed. The equations describing the heat transfer in MD capillary modules were presented and verified experimentally. The equations were derived for the calculation of the feed and distillate temperature at a layer adjacent to the membrane. The heat transfer correlations were implemented in

Marek Gryta; Maria Tomaszewska

1998-01-01

427

Membrane distillation. II. Direct contact MD  

Microsoft Academic Search

Pure water direct contact membrane distillation (DCMD) experiments were used to measure the permeability parameter associated with the molecular diffusion in membrane distillation (MD). The fluxes given by a recently reported MD model, which is based on the dusty-gas model of gas transport through porous media, showed good agreement with the experimental results over the entire range of feed temperatures

Kevin W. Lawson; Douglas R. Lloyd

1996-01-01

428

Distillation of Bell states in open systems  

SciTech Connect

In this work we show that the distillation protocol proposed by P. Chen et al. [Phys. Rev. A 54, 3824 (1996)] allows one to distill Bell states at any time for a system evolving in vacuum and prepared in an initial singlet. It is also shown that the same protocol, applied in nonzero temperature thermal baths, yields a considerable recovering of entanglement.

Isasi, E.; Mundarain, D. [Departamento de Fisica, Seccion de Fenomenos Opticos, Universidad Simon Bolivar, Apartado Postal 89000, Caracas 1080A (Venezuela, Bolivarian Republic of)

2010-04-15

429

Locally accessible information and distillation of entanglement  

SciTech Connect

A different type of complementarity relation is found between locally accessible information and final average entanglement for a given ensemble. It is also shown that in some well-known distillation protocols, this complementary relation is optimally satisfied. We discuss the interesting trade-off between locally accessible information and distillable entanglement for some states.

Ghosh, Sibasish [Department of Computer Science, University of York, Heslington, York, YO10 (United Kingdom); Joag, Pramod [Department of Physics, University of Pune, Ganeshkhind, Pune 411 007 (India); Kar, Guruprasad; Kunkri, Samir [Physics and Applied Mathematics Unit, Indian Statistical Institute, 203, B.T. Road, Kolkata 700 108 (India); Roy, Anirban [Institute of Mathematical Sciences, CIT Campus, Taramani, Chennai 600 113 (India)

2005-01-01

430

Mixed solvent dewaxing of Kuwait middle distillates  

Microsoft Academic Search

Raw distillate fractions of petroleum contain a considerable concentration of paraffin waxes, which leads to a high pour point. However, for some special purposes, a low pour point of these oils is required as well as a fixed viscosity. For this reason, the paraffin waxes have to be removed from the oil distillates. The dewaxing process is one of the

M. J. Ijam; R. S. Al-Ameeri; M. A. Fahim; S. F. Aref

1986-01-01

431

Application of high vacuum fractional distillation to complex mixtures of methyl esters of polyunsaturated fatty acids  

Microsoft Academic Search

A technique for the high vacuum fractional distillation, with a spinning band column, of methyl esters of polyunsaturated\\u000a fatty acids employing a carrier of long chain acetates is described. The carrier is used to facilitate the fractionation of\\u000a minor components and minimize artifact formation in mixtures of methyl esters containing up to six double bonds. The technique\\u000a is demonstrated on

O. S. Privett; J. D. Nadenicek; F. J. Pusch; E. C. Nickell

1969-01-01

432

Design and simulation of an entrainer-enhanced ethyl acetate reactive distillation process  

Microsoft Academic Search

This paper presents an approach to intensify a reactive distillation (RD) process for ethyl acetate (EtAc) production using a mass separation agent (entrainer), and a new process flowsheet with a sidedraw to the RD column. The heterogeneous azeotrope formed by water and EtAc contains less water than that is produced by the esterification reaction. N-butyl acetate is selected as an

Song Hu; Bing-jian Zhang; Xiao-qiong Hou; De-liang Li; Qing-lin Chen

433

Thermal fluid dynamics analysis of gas–liquid flow on a distillation sieve tray  

Microsoft Academic Search

Conventional models for distillation columns are based on equilibrium and non-equilibrium stage concepts, and both consider the fluid dynamics in a macroscopic point of view. The main objective of this work is to apply a CFD model under Eulerian-Eulerian framework for gas–liquid flows, with capability to predict the momentum and thermal phenomena of the multiphase flows. A three-dimensional and transient

D. Noriler; H. F. Meier; A. A. C. Barros; M. R. Wolf Maciel

2008-01-01

434

Qualitative Event-Based Expert Supervision Part 2: Distillation Start-up Condition Monitoring  

Microsoft Academic Search

The solutions to supervise start-up and shut-down operations in close loop are suitable for large industrial systems. Similarly, the batch and semi-continuous processes in order to maintain the operation in a dynamic mode. This paper considers the qualitative event-based expert supervision approach of these problems of a distillation column. The development of a general supervision in this work is based

Flávio Neves Jr.; Joseph Aguilar-martin

1998-01-01

435

Design of a continuous distillation plant for the production of spirits originating from fermented grape  

Microsoft Academic Search

An industrial de-alcoholizing plant and a distillation column were designed, for processing 0.56 kg\\/s (2000 kg\\/h) of fermented grape with an ethanol concentration of 9.0% weight\\/weight, (w\\/w) and a content of solids in suspension, expressed as dry matter, of 5–6% (w\\/w), to obtain a grape-spirit at 80% ethanol (w\\/w). Mass flow rates, heat flux rates and temperatures were first measured

Giovanni Cortella; Carla Da Porto

2003-01-01

436

Fluid Mechanics of Distillation Trays (I): Depth-Averaged Theory and One-Dimensional Flows  

Microsoft Academic Search

Rigorous design of a distillation column requires a better fundamental understanding of the fluid mechanics of bubble formation and global flows on trays than that currently available. To progress beyond the empirical-or correlation-based state of understanding that currently exists, a theoretical and computational framework is described here that is based on reducing the governing set of three-dimensional conservation equations to

Fred K. Wohlhuter; Osman A. Basaran; George M. Harriott

1995-01-01

437

Recycling of acetone by distillation  

SciTech Connect

The Resource Conservation Recovery Act (RCRA) identifies spent acetone solvent as a listed hazardous waste. At Fernald, acetone has been spent that has been contaminated with radionuclides and therefore is identified as a mixed hazardous waste. At the time of this publication there is no available approved method of recycling or disposal of radioactively contaminated spent acetone solvent. The Consent Decree with the Ohio EPA and the Consent Agreement with the United States EPA was agreed upon for the long-term compliant storage of hazardous waste materials. The purpose of this project was to demonstrate the feasibility for safely decontaminating spent acetone to background levels of radioactivity for reuse. It was postulated that through heat distillation, radionuclides could be isolated from the spent acetone.

Brennan, D.L.; Campbell, B.A.; Phelan, J.E.; Harper, M.

1992-09-01

438

Versatile cryogenic rotary positioning systems  

NASA Astrophysics Data System (ADS)

Systems for scan mirror positioning and filter wheel grating and indexing used in the Infrared Background Signature Survey sensor are described. A control loop which incorporates a cryogenic brushless torquer, an ironless inductive position sensor, and associated control electronics is used to achieve precise angular positioning with the angular range of +/- 7.5 deg. The motion programs include step, sawtooth, and staircase operations. A positioning accuracy of greater than 0.03 deg and a position resolution of greater than 0.001 deg have been achieved. Fixation of grating and mirror mechanism during launch is accomplished using short circuiting of motor windings for providing high braking torques. For a filter wheel indexing, the inductive position sensor is replaced by Hall probes, and the torque motor commutation uses Hall sensor signals. The same signals are applied to control the required 12 positions. A Hall sensor located at the filter wheel marks a reference position.

Birner, Robert; Sodeikat, Dieter W.; Ruppert, U.

1990-11-01

439

Cryogenic precooler for superconductive magnets  

SciTech Connect

This patent describes a precooler for initial cooldown of superconductive magnets using a two stage cryocooler and having a two stage interface. It comprises: a mounting flange for securing the precooler to the two stage interface, the flange having an inlet and outlet port; a heat exchanger having passageways for carrying a cryogenic fluid; thermal insulating means for mechanically coupling the heat exchanger and the flange; a first and second stage heat stations coupled to the heat exchanger to provide heat flow between the first and second stage heat stations and the heat exchanger; the first and second stage heat stations spaced apart from one another and the flange to contact the heat stations of the two stage interface when inserted therein; a first thermally insulated pipe connected between one end of the heat exchanger passageway and the inlet port in flow communication; and a second thermally insulated pipe connected between the other end of the heat exchanger passageway and the outlet port.

Dorri, B.; Brzozowski, S.J.

1990-05-22

440

Cryogenic Magnetostrictive Materials and Devices  

NASA Astrophysics Data System (ADS)

Energen has patented KelvinAll™, the first material, to exhibit magnetostrictive properties from elevated temperatures to near absolute zero, opening up a new range of applications for magnetostrictive devices. Magnetostrictive materials change their shape in the presence of a magnetic field. This elongation is precise, predictable, reversible and repeatable thereby enabling practical electromechanical devices. KelvinAll has magnetostriction comparable to Terfenol-D at room temperature and its magnetostriction increases at cryogenic temperatures. Energen has developed and prototyped practical electromechanical devices using KelvinAll. These devices include tuners for superconducting radio frequency (SRF) cavities, components for magnetic refrigerators, flow control valves and precision translation stages some of which will be discussed in greater detail. Energen's KelvinAll products enhance performance, increase reliability and reduce development costs.

Joshi, C. H.; Mavanur, A.; Tai, C.-Y.; Han, Z.-X.; Rodenbush, A. J.; Wong, Y.

2004-06-01

441

Cryogenic vacuumm RF feedthrough device  

DOEpatents

A cryogenic vacuum rf feedthrough device comprising: 1) a probe for insertion into a particle beam; 2) a coaxial cable comprising an inner conductor and an outer conductor, a dielectric/insulating layer surrounding the inner conductor, the latter being connected to the probe for the transmission of higher mode rf energy from the probe; and 3) a high thermal conductivity stub attached to the coaxial dielectric about and in thermal contact with the inner conductor which high thermal conductivity stub transmits heat generated in the vicinity of the probe efficiently and radially from the area of the probe and inner conductor all while maintaining useful rf transmission line characteristics between the inner and outer coaxial conductors.

Wu, Genfa (Yorktown, VA); Phillips, Harry Lawrence (Hayes, VA)

2008-12-30

442

Nuclear reactor control column  

DOEpatents

The nuclear reactor control column comprises a column disposed within the nuclear reactor core having a variable cross-section hollow channel and containing balls whose vertical location is determined by the flow of the reactor coolant through the column. The control column is divided into three basic sections wherein each of the sections has a different cross-sectional area. The uppermost section of the control column has the greatest cross-sectional area, the intermediate section of the control column has the smallest cross-sectional area, and the lowermost section of the control column has the intermediate cross-sectional area. In this manner, the area of the uppermost section can be established such that when the reactor coolant is flowing under normal conditions therethrough, the absorber balls will be lifted and suspended in a fluidized bed manner in the upper section. However, when the reactor coolant flow falls below a predetermined value, the absorber balls will fall through the intermediate section and into the lowermost section, thereby reducing the reactivity of the reactor core and shutting down the reactor.

Bachovchin, Dennis M. (Plum Borough, PA)

1982-01-01

443

Predictive control of distillation processes  

SciTech Connect

In this study, predictive control is applied to two fundamental control problems found in most distillation processes: averaging level control and product quality control. An optimal averaging level control problem is defined and solved for a surge tank system. Two averaging level controllers, the ramp controller and the optimal predictive controller, are developed utilizing the optimal control policy. The ramp controller is compared with seven averaging level control schemes discussed in the literature for a variety of inlet flow step disturbances and maximum level specifications. The optimal predictive controller, a feedforward/feedback controller based on an extension of the optimal control law, is compared with previously published classical and predictive averaging level controllers for step and sinusoidal inlet flow disturbances. A predictive, computer control algorithm (DMC) is applied to dual composition control of moderate and high purity, binary distillation towers. In this study, nonlinear dynamic simulations are used to evaluate the performance of DMC for the dual composition control problem. Modifications to the DMC algorithm which compensate for process nonlinearity are compared. The first approach incorporates multivariate gain and time constant scheduling using a simple model to update the important process model parameters on-line. This approach results in a significant improvement in control performance over e standard application of DMC. The second approach involves variable transformations to reduce process nonlinearity. The predictive control algorithm is then applied to the transformed (but more linear) system. For the transformations used in this study, the improvement in control performance for load disturbances is not very significant due to the fact that the transformations did not linearize both of the loops.

McDonald, K.A.

1986-01-01

444

Entanglement distillation from Gaussian input states  

NASA Astrophysics Data System (ADS)

Entanglement distillation is an essential protocol for long-distance quantum communications, typically for extending the range of quantum key distribution. In the field of continuous variable quantum information processing, quantum as well as classical information is encoded in the light field quadratures, often in the form of Gaussian states. However, distillation from Gaussian input states has not yet been accomplished. It is made difficult by a prominent no-go theorem stating that no Gaussian operation can distill Gaussian states. Here we demonstrate, for the first time, such distillation from Gaussian input states, realized by the implementation of non-Gaussian operations. By subtracting one or two photons, a large gain of entanglement was observed. For two photons, Gaussian-like entanglement was also improved. Other than quantum key distribution, this distilled entanglement can also be used for downstream applications such as high-fidelity quantum teleportation and a loophole-free Bell test.

Takahashi, Hiroki; Neergaard-Nielsen, Jonas S.; Takeuchi, Makoto; Takeoka, Masahiro; Hayasaka, Kazuhiro; Furusawa, Akira; Sasaki, Masahide

2010-03-01

445

Reduced pressure distillation of an alcoholic mixture  

US Patent & Trademark Office Database

The present invention relates to a method for distilling an alcoholic mixture under reduced pressure, wherein a portion of the fluid alcoholic mixture is distilled at a temperature below about 0.degree. C. such that the fluid alcoholic mixture remains fluid while distilling. The present invention further relates to condensing the alcoholic distillate with a first condenser at a first condenser temperature of from about -269.degree. C. to about -15.degree. C. to provide a first alcoholic condensate. The alcoholic mixtures contemplated for use according to the method of the present invention include, but are not limited to, gin, vodka, rum, or neutral spirits. The present invention also relates to an alcoholic beverage prepared by the reduced pressure distillation method of the invention.

2010-08-24

446

Composite Column Design  

NSDL National Science Digital Library

This module, created by Craig Johnson of Central Washington University, "incorporates engineering design (using smart spreadsheets) into a laboratory activity focusing on columns made of composite materials." In this lab, students will simulate the use of composite columns and use spreadsheets to optimize design for engineering performance. The module features an abstract, objective, curriculum overview, procedures, mathematical calculations and references. The objectives of the module are to design appropriate composite column structures, fabricate composite using appropriate methods and critically evaluate composite's performance referencing predications. This is a great resource to either enhance or create new curriculum for instructors.

Johnson, Craig

2009-09-30

447

Closed-Loop Helical Distillation Apparatus. Progress Report.  

National Technical Information Service (NTIS)

The objectives of the project are to: design and construct a more efficient mash distillation unit; reduce physical size and material cost in distillation; use readily available material in the construction of distillation equipment; and improve the opera...

D. L. Gahimer

1981-01-01

448

27 CFR 19.32 - Experimental distilled spirits plants.  

Code of Federal Regulations, 2013 CFR

...false Experimental distilled spirits plants. 19.32 Section 19.32 Alcohol...TREASURY ALCOHOL DISTILLED SPIRITS PLANTS Administrative and Miscellaneous Provisions...32 Experimental distilled spirits plants. (a) General. The...

2013-04-01

449

Statistical-overlap theory of column switching in gas chromatography: applications to flavor and fragrance compounds.  

PubMed

First-column gas chromatograms (GCs) of hundreds of flavor and fragrance compounds, and second-column GCs of specific regions of these GCs, are predicted using thermodynamic databases in commercial software. A statistical-overlap theory of column switching with cryogenic focusing then is developed by mimicking the predicted GCs by two kinds of Monte Carlo simulations. In the first kind, a probability distribution is calculated for the number of compounds in a region of the first-column GC, based on the number of observed peaks in the region, the number of observed peaks in the second-column GC, and the retention-time distributions and breadths of single-component peaks in both GCs. In the second kind, criteria are established for the theory's application. The theory is applied to 12 regions of first-column GCs. The theory predicts the number of compounds in all of them and shows that separation rarely is complete in second-column GCs, when 10 or more compounds are transferred between columns. The theory also rationalizes the tedious search required to find good separation conditions by showing that column-switching gas chromatography with cryogenic focusing is inherently statistical. The number of peaks in the second-column GC can be greater than, less than, or equal to the number of peaks in the relevant region of the first-column GC, and the good conditions sought by researchers to substantially improve separation correspond to favorable "rolls of the dice" found only by trial and error. PMID:12038754

Samuel, Clint; Davis, Joe M

2002-05-15

450

A brief overview of cryogenics in China  

NASA Astrophysics Data System (ADS)

In this paper general aspects of cryogenics in China are introduced, and applications of cryogenics in the space programme are described briefly, such as its application to the Long March 3 rocket vehicles with LH2/LO2 engines, the development of a 750 dm 3 hr -1 liquid hydrogen plant and railway tank cars with 60 and 70 m 3 capacities. In addition, the progress of various cryogenic techniques in China is presented, such as the FY-1 radiation refrigerator loaded on a meteorology satellite, regenerative cryocoolers of the Gifford-McMahon, Solvay, Vuilleumier, Stirling and pulse tube types, and the KM-3 and KM-4 space simulation facilities. Finally, the paper discusses current education about refrigeration and cryogenics for undergraduates and graduates.

Li, S.-M.

451

Cryogenic target formation using cold gas jets  

DOEpatents

A method and apparatus using cold gas jets for producing a substantially uniform layer of cryogenic materials on the inner surface of hollow spherical members having one or more layers, such as inertially imploded targets are disclosed. By vaporizing and quickly refreezing cryogenic materials contained within a hollow spherical member, a uniform layer of the materials is formed on an inner surface of the spherical member. Basically the method involves directing cold gas jets onto a spherical member having one or more layers or shells and containing the cryogenic material, such as a deuterium-tritium (DT) mixture, to freeze the contained material, momentarily heating the spherical member so as to vaporize the contained material, and quickly refreezing the thus vaporized material forming a uniform layer of cryogenic material on an inner surface of the spherical member. 4 figs.

Hendricks, C.D.

1980-02-26

452

Cryogenic Applications of Commercial Electronic Components.  

National Technical Information Service (NTIS)

We have developed a range of techniques useful for constructing analog and digital circuits for operation in a liquid Helium environment (4.2K), using commercially available low power components. The challenges encountered in designing cryogenic electroni...

D. J. Benford E. D. Buchanan E. J. Wollack J. B. Forgione S. H. Moseley

2012-01-01

453

Rotary bayonets for cryogenic and vacuum service.  

National Technical Information Service (NTIS)

Rotary bayonets were designed, tested, and installed for liquid nitrogen, liquid argon, and vacuum service. This paper will present the design, testing, and service record for two sizes of vacuum jacketed cryogenic rotary bayonets and two sizes of vacuum ...

R. A. Rucinski K. D. Dixon R. Krasa K. J. Krempetz G. T. Mulholland

1993-01-01

454

Surface Tension Confined Liquid Cryogen Cooler (STCLCC).  

National Technical Information Service (NTIS)

A cryogenic cooler is provided for use in craft such as launch, orbital, and space vehicles subject to substantial vibration, changes in orientation, and weightlessness. The cooler contains a small pore, large free volume, low density material to restrain...

S. H. Castles M. E. Schein

1988-01-01

455

Cryogenic Engineering for Superconducting Power Transmission Systems.  

National Technical Information Service (NTIS)

The successful introduction of helium-cooled (superconducting) transmission systems into electric utility networks will open a vast market for cryogenic engineering components and services. If only 10 percent of the anticipated investment in transmission ...

E. B. Forsyth

1976-01-01

456

Flight Testing of a Cryogenically Cooled Hygrometer.  

National Technical Information Service (NTIS)

The cryogenically cooled, optical dew/frost point hygrometer was developed to provide a fast response aircraft instrument for the measurement of very low frost-point temperatures encountered at the higher altitudes. A detailed description of the device is...

J. F. Church R. M. Peirce

1973-01-01

457

Hermeticity of Three Cryogenic Calorimeter Geometries.  

National Technical Information Service (NTIS)

We calculate the effect of cracks and dead material on resolution in three simplified cryogenic calorimeter geometries, using a crude approximation that neglects transverse shower spreading and considers only a small set of incident angles. For each dead ...

M. Strovink W. J. Wormersley G. E. Forden

1989-01-01

458

Refrigeration for Cryogenic Sensors and Electronic Systems.  

National Technical Information Service (NTIS)

The purpose of the meeting was to discuss progress in the development of refrigeration systems which have been specialized for use with cryogenic sensors and electronic systems. The meeting focused primarily on the temperature range below 20 K and cooling...

D. B. Sullivan J. E. Zimmerman S. E. McCarthy

1981-01-01

459

Cryogenic target formation using cold gas jets  

DOEpatents

A method and apparatus using cold gas jets for producing a substantially uniform layer of cryogenic materials on the inner surface of hollow spherical members having one or more layers, such as inertially imploded targets. By vaporizing and quickly refreezing cryogenic materials contained within a hollow spherical member, a uniform layer of the materials is formed on an inner surface of the spherical member. Basically the method involves directing cold gas jets onto a spherical member having one or more layers or shells and containing the cryogenic material, such as a deuterium-tritium (DT) mixture, to freeze the contained material, momentarily heating the spherical member so as to vaporize the contained material, and quickly refreezing the thus vaporized material forming a uniform layer of cryogenic material on an inner surface of the spherical member.

Hendricks, Charles D. (Livermore, CA)

1981-01-01

460

Cryogenic target formation using cold gas jets  

DOEpatents

A method and apparatus using cold gas jets for producing a substantially uniform layer of cryogenic materials on the inner surface of hollow spherical members having one or more layers, such as inertially imploded targets. By vaporizing and quickly refreezing cryogenic materials contained within a hollow spherical member, a uniform layer of the materials is formed on an inner surface of the spherical member. Basically the method involves directing cold gas jets onto a spherical member having one or more layers or shells and containing the cryogenic material, such as a deuterium-tritium (DT) mixture, to freeze the contained material, momentarily heating the spherical member so as to vaporize the contained material, and quickly refreezing the thus vaporized material forming a uniform layer of cryogenic material on an inner surface of the spherical member.

Hendricks, Charles D. (Livermore, CA)

1980-01-01

461

Cryogenic Hydrogen-Induced Air Liquefaction Technologies.  

National Technical Information Service (NTIS)

Extensively utilizing a special advanced airbreathing propulsion archives database, as well as direct contacts with individuals who were active in the field in previous years, a technical assessment of cryogenic hydrogen-induced air liquefaction, as a pro...

W. J. D. Escher

1990-01-01

462

Design Concepts for the ASTROMAG Cryogenic System.  

National Technical Information Service (NTIS)

This paper describes the proposed cryogenic system used to cool the superconducting magnet for the Space Station based ASTROMAG Particle Astrophysics Facility. This 2-meter diameter superconducting magnet will be cooled using stored helium II. The paper p...

M. A. Green S. Castles

1987-01-01

463

Cryogenic engineering for superconducting power transmission systems  

Microsoft Academic Search

The successful introduction of helium-cooled (superconducting) transmission systems into electric utility networks will open a vast market for cryogenic engineering components and services. If only 10 percent of the anticipated investment in transmission facilities in the U.S. after 1990 is made in helium-cooled systems this will represent a potential annual market of over $120,000,000 for the manufacturers of cryogenic components.

Forsyth

1976-01-01

464

A brief overview of cryogenics in China  

Microsoft Academic Search

In this paper general aspects of cryogenics in China are introduced, and applications of cryogenics in the space programme are described briefly, such as its application to the Long March 3 rocket vehicles with LH2LO2 engines, the development of a 750 dm3 hr?1 liquid hydrogen plant and railway tank cars with 60 and 70 m3 capacities. In addition, the progress

S.-M. Li

1995-01-01

465

Development of cryogenic rotatable heat transfer joints  

Microsoft Academic Search

A summary of cryogenic rotatable heat transfer joint technology development, at Rockwell International Space Division, is presented. Starting with the flight qualified radiative joint on the RM-20B IR sensor of the early 70's, leading to rotatable heat pipe joint, gas conductive joints, rolling-contact-conductance joints, and the more recent work on development and evaluation of cryogenic rotatable seals and mechanical interfaces.

J. A. Sadunas; Z. F. Backovsky; D. E. Wilson

1992-01-01

466

Advanced Devices for Cryogenic Thermal Management  

Microsoft Academic Search

This paper describes six advanced cryogenic thermal management devices\\/subsystems developed by Swales Aerospace for ground\\/space-based applications of interest to NASA, DoD, and the commercial sector. The devices\\/subsystems described herein include the following: (a) a differential thermal expansion cryogenic thermal switch (DTE-CTSW) constructed with high purity aluminum end-pieces and an Ultem support rod for the 6 K Mid-Infrared Instrument (MIRI) on

D. Bugby; C. Stouffer; J. Garzon; M. Beres; A. Gilchrist

2006-01-01

467

DE-ENTRAINMENT COLUMN  

DOEpatents

A de-entrainnnent colunnn is described for removing substances from a stream of vapor coming from a distillation apparatus. The device comprises a hollow cylindrical body mounted with its axis vertical on a flange on the upper slde of a vaporizing vessel; two sintered metal circular discs through which all the vapor passes mounted in axially spaced relationship in the cylindrical body; and two semi-circular baffle plates mounted in spaced relationship between the discs.

Mooradian, A.J.

1958-07-01

468

Flight Performance of the AKARI Cryogenic System  

NASA Astrophysics Data System (ADS)

We describe the flight performance of the cryogenic system of the infrared astronomical satellite AKARI, which was successfully launched on 2006 February 21 (UT). AKARI carries a 68.5 cm telescope together with two focal-plane instruments, Infrared Cameras and Far Infrared Surveyor, all of which are cooled down to cryogenic temperature to achieve superior sensitivity. AKARI has a unique cryogenic system, which consists of cryogen (liquid helium) and mechanical coolers (2-stage Stirling coolers). With the help of mechanical coolers, 179 L (26.0 kg) of super-fluid liquid helium can keep the instruments cryogenically cooled for more than 500 days. The on-orbit performance of the AKARI cryogenics is consistent with the design and a pre-flight test, and the boil-off gas flow rate is as small as 0.32 mg s^{-1}. We observed an increase in the major axis of the AKARI orbit, which can be explained by thrust due to the thermal pressure of vented helium gas.

Nakagawa, T.; Enya, K.; Hirabayashi, M.; Kaneda, H.; Kii, T.; Kimura, Y.; Matsumoto, T.; Murakami, H.; Murakami, M.; Narasaki, K.; Narita, M.; Ohnishi, A.; Tsunematsu, S.; Yoshida, S.

2007-10-01

469

D0 Cryogenic System Operator Training  

SciTech Connect

D0 is a collider detector. It will be operating and doing physics at the same time as CDP, therefore it has been decided to train CDP operators to operate and respond to the D0 cryogenic control system. A cryogenic operator will be required to be in residence at D0, during the cooldown and liquid Argon fill of any of the calorimeters. The cryogenic system at D0 is designed to be unmanned during steady state operation. CDP operations has 2 man cryogenic shifts 24 hours a day. It is intended that CDP operators monitor the D0 cryogenic systems, evaluate and respond to alarms, and notify a D0 cryo expert in the event of an unusual problem. A D0 cryogenic system view node has been installed at CDP to help facilitate these goals. It should be noted that even though the CDP view node is a fully operational node it is intended that it be more of an information node and is therefore password protected. The D0 cryo experts may reassess the use of the CDP node at a later date based on experience and operating needs. This engineering note outlines the format of the training and testing given to the CDP operators to make them qualified D0 operators.

Markley, D.; /Fermilab

1991-11-30

470

Fractional distillation of acid contaminants from sevoflurane.  

PubMed

On two occasions, sevoflurane distributed for clinical practice has been found to be contaminated with compounds thought to include hydrogen fluoride (HF) and silicon tetrafluoride (SiF(4)). Both compounds can produce pulmonary injury. However, injury would require fractional distillation of the compounds during the course of sevoflurane vaporization. We hypothesized that such distillation would occur and that the compounds would vaporize more rapidly than would sevoflurane. Thus, we tested whether fractional distillation occurs during vaporization of sevoflurane containing HF or SiF(4), or from sevoflurane containing HF converted to other compounds by contact with glass. Vaporization of < 10% of the sevoflurane distilled 65%-99% of these compounds, SiF(4) distilling most rapidly, HF (converted to other acidic compounds, including SiF(4)) distilling nearly as rapidly, and HF slowest. Nuclear magnetic resonance studies indicated that HF interaction with glass changed all HF to three other compounds, one being SiF(4) and the others being unknown. HF and SiF4 distill from sevoflurane more rapidly than sevoflurane is vaporized. Measurement of acidity after sevoflurane administration may not reveal a previous presence of such contaminants. PMID:11004061

Laster, M J; Eger, E I; Cherry, W R; Gong, D

2000-10-01

471

Distillation: Still towering over other options  

SciTech Connect

Distillation dominates separations in the chemical process industries (CPI), at least for mixtures that normally are processed as liquids. The authors fully expect that distillation will continue to be the method of choice for many separations, and the method against which other options must be compared. So, in this article, they will put into some perspective just why distillation continues to reign as the king of separations, and what steps are being taken to improve its applicability and performance, as well as basic understanding of the technique.

Kunesh, J.G. [Fractionation Research, Inc., Stillwater, OK (United States); Kister, H.Z. [Brown and Root, Inc., Alhambra (Canada); Lockett, M.J. [Praxair, Inc., Tonawanda, NY (United States); Fair, J.R. [Univ. of Texas, Austin, TX (United States)

1995-10-01

472

Design and construction of a packed column simulator operating under atmospheric and reduced pressure  

Microsoft Academic Search

Distillation under reduced pressure for the separation of constituants is considered. To avoid thermic damage in columns, the most important parameters are pressure loss and resistance time. The development of a simulator, enabling the determination of the hydrodynamic parameters with the mixture air-water under different pressures for any given mixture, is carried out. A bibliographic study and a reference study,

Abdelhamid Messaoudene

1989-01-01

473

Design Parameters for Cryogenic Thermosyphons  

NASA Astrophysics Data System (ADS)

Cryogenic thermosyphons are the thermal conductors of choice for a variety of applications such as conduction-cooled superconducting devices. They exhibit a small effective thermal resistance at small cross-sections. A careful design, however, is crucial to ensure sufficient heat transport for all possible heatloads. The aim of this work is to obtain experimental results on critical limitations and the effective thermal conductivity dependent on the length, the cross-sectional area, and the working liquid fill level of a thermosyphon for different heatloads. For the experiments, a modular thermosyphon was designed with 5 different adiabatic tubes of length [cm]/cross-sectional diameter [cm] 10/1, 10/2, 30/0.5, 30/1, 30/2, which can be mounted between condenser and evaporator. The thermosyphon was operated with different fill levels of either nitrogen or neon and different heatloads. The effective thermal conductivity between condenser and evaporator was determined, dependent on the design parameters mentioned above. Additionally, the useful temperature range of operation was determined, and limitations were monitored and visualized using a built-in camera. The results can support the proper design of thermosyphons for dedicated applications by providing information about the heat transport capability for different thermosyphon design parameters.

Timinger, H.; David, B.; Eckart, R.; Overweg, J.

2008-03-01

474

Cryogenic helium gas convection research  

NASA Astrophysics Data System (ADS)

This is a report prepared by a group interested in doing research in thermal convection using the large scale refrigeration facilities available at the SSC Laboratories (SSCL). The group preparing this report consists of Michael McAshan at SSCL, Robert Behringer at Duke University, Katepalli Sreenivasan at Yale University, Xiao-Zhong Wu at Northern Illinois University and Russell Donnelly at the University of Oregon, who served as Editor for this report. This study reports the research and development opportunities in such a project, the technical requirements and feasibility of its construction and operation, and the costs associated with the needed facilities and support activities. The facility will be a unique national resource for studies of high-Reynolds-number and high-Rayleigh-number and high Rayleigh number turbulence phenomena, and is one of the six items determined as suitable for potential funding through a screening of Expressions of Interest. The proposed facility is possible only because of the advanced cryogenic technology available at the SSCL. Typical scientific issues to be addressed in the facility will be discussed. It devolved during our study, that while the main experiment is still considered to be the thermal convection experiment discussed in our original Expression of Interest, there are now a very substantial set of other, important and fundamental experiments which can be done with the large cryostat proposed for the convection experiment. We believe the facility could provide several decades of front-line research in turbulence, and shall describe why this is so.

Behringer, Robert P.; Donnelly, Russell J.; McAshan, Michael; Maddocks, James; Sreenivasan, Katepalli; Swanson, Chris; Wu, Xaio-Zhong

1994-10-01

475

Cryogenic pulsed inductive microwave magnetometer  

NASA Astrophysics Data System (ADS)

A cryogenic pulsed inductive microwave magnetometer is used to characterize the switching dynamics in thin-film magnetic materials at low temperatures and microwave frequencies. The system is contained inside a 20-cm-diam ultrahigh vacuum chamber and cooled by a cryopump that allows measurements between 20 and 350 K. A temperature controller regulates the sample temperature using two silicon diodes as sensors. Applied magnetic fields of up to 36 kA/m (450 Oe) are generated by a four-pole, water-cooled electromagnet with independent control of each axis. Magnetic switching in the sample is driven by high-speed current step pulses in a coplanar waveguide structure with the sample placed in a flip-chip configuration. A 20 GHz sampling oscilloscope is used to record the dynamics of the magnetic reorientation. The switching dynamics are given for a 10-nm-thick Ni-Fe film at 30 K in response to a 1 kA/m field step.

Kos, A. B.; Nibarger, J. P.; Lopusnik, R.; Silva, T. J.; Celinski, Z.

2003-05-01

476

Distillation modeling for a uranium refining process  

SciTech Connect

As part of the spent fuel treatment program at Argonne National Laboratory, a vacuum distillation process is being employed for the recovery of uranium following an electrorefining process. Distillation of a salt electrolyte, containing a eutectic mixture of lithium and potassium chlorides, from uranium is achieved by a simple batch operation and is termed {open_quotes}cathode processing{close_quotes}. The incremental distillation of electrolyte salt will be modeled by an equilibrium expression and on a molecular basis since the operation is conducted under moderate vacuum conditions. As processing continues, the two models will be compared and analyzed for correlation with actual operating results. Possible factors that may contribute to aberrations from the models include impurities at the vapor-liquid boundary, distillate reflux, anomalous pressure gradients, and mass transport phenomena at the evaporating surface. Ultimately, the purpose of either process model is to enable the parametric optimization of the process.

Westphal, B.R.

1996-03-01

477

Minimizing corrosion in coal liquid distillation  

DOEpatents

In an atmospheric distillation tower of a coal liquefaction process, tower materials corrosion is reduced or eliminated by introduction of boiling point differentiated streams to boiling point differentiated tower regions.

Baumert, Kenneth L. (Emmaus, PA); Sagues, Alberto A. (Lexington, KY); Davis, Burtron H. (Georgetown, KY)

1985-01-01

478

21 CFR 184.1848 - Starter distillate.  

Code of Federal Regulations, 2010 CFR

...the remainder is a mixture of butterlike flavor compounds. Diacetyl is the major flavor component, constituting as much as 80 to 90 percent of the mixture of organic flavor compounds. Besides diacetyl, starter distillate contains minor amounts of...

2010-01-01

479

21 CFR 184.1848 - Starter distillate.  

Code of Federal Regulations, 2010 CFR

...the remainder is a mixture of butterlike flavor compounds. Diacetyl is the major flavor component, constituting as much as 80 to 90 percent of the mixture of organic flavor compounds. Besides diacetyl, starter distillate contains minor amounts of...

2009-04-01

480

New catalysts for hydrotreating heavy distillates  

Microsoft Academic Search

Compares the activity of experimental-commercial batches of type GO catalysts with the activity of alumina-cobaltmolybdenum (ACM) and alumina-nickel-molybdenum silicate (ANMS) catalysts in the hydrodesulfurization of a 350-500C vacuum distillate from Romashkino crude containing 2% sulfur and 0.1% nitrogen by weight. Finds that the GO-115, GO-116, and GO-117 catalysts are promising materials for use in hydrotreating vacuum distillates because their activities

A. N. Chagovets; L. N. Osipov; B. L. Lebedev; I. Ya. Perezhigina; A. V. Agafonov

1982-01-01

481

Multipartite secret key distillation and bound entanglement  

SciTech Connect

Recently it has been shown that quantum cryptography beyond pure entanglement distillation is possible and a paradigm for the associated protocols has been established. Here we systematically generalize the whole paradigm to the multipartite scenario. We provide constructions of new classes of multipartite bound entangled states, i.e., those with underlying twisted Greenberger-Horne-Zeilinger (GHZ) structure and nonzero distillable cryptographic key. We quantitatively estimate the key from below with the help of the privacy squeezing technique.

Augusiak, Remigiusz; Horodecki, Pawel [Faculty of Applied Physics and Mathematics, Gdansk University of Technology, Narutowicza 11/12, 80-952 Gdansk (Poland) and ICFO-Institute Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona) (Spain); Faculty of Applied Physics and Mathematics, Gdansk University of Technology, Narutowicza 11/12, 80-952 Gdansk (Poland)

2009-10-15

482

Fractional distillation of hydrocarbons from coal  

SciTech Connect

Process and apparatus is disclosed for recovering volatile distillates from coal, and other solid carbonaceous fuel sources, by heating the top surface of a bilayer of coal formed of an upper layer of recycled coal and a lower layer of green coal, maintaining the lower level of green coal at a temperature cool enough to condense constituents distilled from the upper layer of recycle coal, and recycling the once passed green coal as recycle coal.

Esztergar, E.P.

1983-07-26

483

Non-pinched, minimum energy distillation designs  

Microsoft Academic Search

Non-pinched, minimum energy solutions are important class of distillation designs that offer the potential advantage of a better trade-off between capital investment and operating costs. In this paper, two important tasks associated with non-pinched distillation designs are studied. Thus the novel contributions of this work to the literature are(1)A comprehensive methodology for finding non-pinched minimum energy designs.(2)Understanding of the reasons

Amit S. Amale; Angelo Lucia

2008-01-01

484

Nonequilibrium Positive Column III.  

NASA Astrophysics Data System (ADS)

Previous work has shown that the first principles nonlocal kinetic method [1] is closely approximated by the nonlocal moment method [2] in positive column analysis, and that the transition from nonequilibrium to equilibrium at sufficiently high NR (gas density × radius) can be studied by the nonlocal moment method [3]. The present paper describes the derivation of a quantitative condition that the parameter NR must satisfy in order for local equilibrium to prevail in the low pressure positive column discharge. The derivation is based on the electron energy balance equation resulting from the two-term Legendre expansion technique of solving the Boltzmann equation for the electron energy distribution function. Use of the quantitative condition is illustrated by application to a positive column discharge in neon. [1]D. Uhrlandt and R. Winkler, J. Phys. D 29, 115 (1996). [2]J. H. Ingold, Phys. Rev. E 56, 5932 (1997). [3]J. H. Ingold, Bull. Am. Phys. Soc. 43, 1466 (1998).

Ingold, J. H.

1999-10-01

485

Quantum Nonlocal Boxes Exhibit Stronger Distillability  

NASA Astrophysics Data System (ADS)

The hypothetical nonlocal box (NLB) proposed by Popescu and Rohrlich allows two spatially separated parties, Alice and Bob, to exhibit stronger than quantum correlations. If the generated correlations are weak, they can sometimes be distilled into a stronger correlation by repeated applications of the NLB. Motivated by the limited distillability of NLBs, we initiate here a study of the distillation of correlations for nonlocal boxes that output quantum states rather than classical bits (qNLBs). We propose a new protocol for distillation and show that it asymptotically distills a class of correlated quantum nonlocal boxes to the value (1)/(2)(3? {3}+1) ? 3.098076, whereas in contrast, the optimal non-adaptive parity protocol for classical nonlocal boxes asymptotically distills only to the value 3.0. We show that our protocol is an optimal non-adaptive protocol for 1, 2 and 3 qNLB copies by constructing a matching dual solution for the associated primal semidefinite program (SDP). We conclude that qNLBs are a stronger resource for nonlocality than NLBs. The main premise that develops from this conclusion is that the NLB model is not the strongest resource to investigate the fundamental principles that limit quantum nonlocality. As such, our work provides strong motivation to reconsider the status quo of the principles that are known to limit nonlocal correlations under the framework of qNLBs rather than NLBs.

Høyer, Peter; Rashid, Jibran

2013-06-01

486

Development of Advanced Tools for Cryogenic Integration  

NASA Astrophysics Data System (ADS)

This paper describes four advanced devices (or tools) that were developed to help solve problems in cryogenic integration. The four devices are: (1) an across-gimbal nitrogen cryogenic loop heat pipe (CLHP) (2) a miniaturized neon CLHP; (3) a differential thermal expansion (DTE) cryogenic thermal switch (CTSW) and (4) a dual-volume nitrogen cryogenic thermal storage unit (CTSU). The across-gimbal CLHP provides a low torque, high conductance solution for gimbaled cryogenic systems wishing to position their cryocoolers off-gimbal. The miniaturized CLHP combines thermal transport, flexibility, and thermal switching (at 35 K) into one device that can be directly mounted to both the cooler cold head and the cooled component. The DTE-CTSW, designed and successfully tested in a previous program using a stainless steel tube and beryllium (Be) end-pieces, was redesigned with a polymer rod and high-purity aluminum (Al) end-pieces to improve performance and manufacturability while still providing a miniaturized design. Lastly, the CTSU was designed with a 6063 Al heat exchanger and integrally welded, segmented, high purity Al thermal straps for direct attachment to both a cooler cold head and a Be component whose peak heat load exceeds its average load by 2.5 times. For each device, the paper will describe its development objective, operating principles, heritage, requirements, design, test data and lessons learned.

Bugby, D. C.; Marland, B. C.; Stouffer, C. J.; Kroliczek, E. J.

2004-06-01

487

Advanced cryogenics for cutting tools. Final report  

SciTech Connect

The purpose of the investigation was to determine if cryogenic treatment improved the life and cost effectiveness of perishable cutting tools over other treatments or coatings. Test results showed that in five of seven of the perishable cutting tools tested there was no improvement in tool life. The other two tools showed a small gain in tool life, but not as much as when switching manufacturers of the cutting tool. The following conclusions were drawn from this study: (1) titanium nitride coatings are more effective than cryogenic treatment in increasing the life of perishable cutting tools made from all cutting tool materials, (2) cryogenic treatment may increase tool life if the cutting tool is improperly heat treated during its origination, and (3) cryogenic treatment was only effective on those tools made from less sophisticated high speed tool steels. As a part of a recent detailed investigation, four cutting tool manufacturers and two cutting tool laboratories were queried and none could supply any data to substantiate cryogenic treatment of perishable cutting tools.

Lazarus, L.J.

1996-10-01

488

Advanced Devices for Cryogenic Thermal Management  

NASA Astrophysics Data System (ADS)

This paper describes six advanced cryogenic thermal management devices/subsystems developed by Swales Aerospace for ground/space-based applications of interest to NASA, DoD, and the commercial sector. The devices/subsystems described herein include the following: (a) a differential thermal expansion cryogenic thermal switch (DTE-CTSW) constructed with high purity aluminum end-pieces and an Ultem support rod for the 6 K Mid-Infrared Instrument (MIRI) on the James Webb Space Telescope (JWST) (b) a quad-redundant DTE-CTSW assembly for the 35 K science instruments (NIRCam, NIRSpec, and FGS) mounted on the JWST Integrated Science Instrument Module (ISIM) (c) a cryogenic diode heat pipe (CDHP) thermal switching system using methane as the working fluid for the 100 K CRISM hyperspectral mapping instrument on the Mars Reconnaissance Orbiter (MRO) and (d) three additional devices/subsystems developed during the AFRL-sponsored CRYOTOOL program, which include a dual DTE-CTSW/dual cryocooler test bed, a miniaturized neon cryogenic loop heat pipe (mini-CLHP), and an across gimbal cryogenic thermal transport system (GCTTS). For the first three devices/subsystems mentioned above, this paper describes key aspects of the development efforts including concept definition, design, fabrication, and testing. For the latter three, this paper provides brief overview descriptions as key details are provided in a related paper.

Bugby, D.; Stouffer, C.; Garzon, J.; Beres, M.; Gilchrist, A.

2006-04-01

489

Influence of multicomponent mass transfer on homogeneous azeotropic distillation  

Microsoft Academic Search

Residue-curve and distillation-line maps are useful tools for the design of azeotropic distillation sequences. The calculation of residue curves uses the assumption that the vapour and liquid are always in equilibrium. The computation of distillation lines assumes that the vapour and liquid leaving a tray are in equilibrium. In this work, the equations defining residue curves and distillation lines are

F. J. L. Castillo; G. P. Towler

1998-01-01

490

27 CFR 17.162 - Receipt of distilled spirits.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Receipt of distilled spirits. 17.162 Section 17.162 Alcohol...LIQUORS DRAWBACK ON TAXPAID DISTILLED SPIRITS USED IN MANUFACTURING NONBEVERAGE PRODUCTS...Records § 17.162 Receipt of distilled spirits. (a) Distilled spirits...

2010-04-01

491

Local Gaussian operations can enhance continuous-variable entanglement distillation  

Microsoft Academic Search

Entanglement distillation is a fundamental building block in long-distance quantum communication. Though known to be useless on their own for distilling Gaussian entangled states, local Gaussian operations may still help to improve non-Gaussian entanglement distillation schemes. Here we show that by applying local squeezing operations, both the performance and the efficiency of existing distillation protocols can be enhanced. We derive

ShengLi Zhang; Peter van Loock

2011-01-01

492

Nocturnal distillation in basin-type solar stills  

Microsoft Academic Search

Nocturnal distillation, which dominates the output of deep basin stills, has been studied experimentally. From observations of continuous temperature and distillate measurements, the important factors affecting night-time distillation are identified. A dimensionless analysis of these factors was carried out in an attempt to generalise the night-time behaviour of solar stills. The results indicate that the distillate output is uniquely determined

S. O. Onyegegbu

1986-01-01

493

21 CFR 882.4250 - Cryogenic surgical device.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Cryogenic surgical device. 882.4250 Section 882.4250...DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4250 Cryogenic surgical device. (a) Identification. A...

2013-04-01

494

The unusual behavior of extractive distillation--reversing the volatility of the acetone-isopropyl ether system  

SciTech Connect

Extractive distillation can not only negate azeotropes to produce pure compounds by rectification but in some cases will reverse the volatility and bring out the less volatile component before the more volatile component. As an example, isopropyl ether, b.p. = 68.5/sup 0/C, was distilled off as the overhead from mixtures with acetone, b.p. = 56.2/sup 0/C, leaving the acetone in the stillpot and column until all the isopropyl ether was removed. This reversal phenomenon does not occur in the isopropyl ether-methyl ethyl ketone system, although the azeotrope is negated.

Berg, L.; Yeh, A.-I.

1985-03-01

495

A PROCESS FOR SEPARATING AZEOTROPIC MIXTURES BY EXTRACTIVE AND CONVECTIVE DISTILLATION  

DOEpatents

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)

Frazer, J.W.

1961-12-19

496

High-pressure distillation of crude ZrCl/sub 4/. Open File report  

SciTech Connect

A high-pressure fractionation column for separation of HfC14 and ZrC14 was built to evaluate the claims of a 1976 Japanese patent (76 65,093). A 35.5-in by 3/4-in ID stainless steel 316 column packed with Inconel 600 helices was operated at 40 kg/sq cm (39 atm) pressure with reboiler and overhead condenser temperatures of 471 and 455 C, respectively. The total reflux operation produced ZrC14, with 800 mol ppm HfC14 in the reboiler and with 5.2 mol pct HfC14 in the overhead. A 4.7-in height equivalent to a theoretical plate was determined using a variable separation factor. Although column corrosion partially obscured the redistribution tendencies of impurities, uranium clearly stayed in the reboiler. Of the potential construction metals exposed during distillation, Inconel 625 and Hastelloy C-276 showed the least corrosion.

Skaggs, R.L.; Younghans, J.; Rogers, D.T.; Hunter, D.B.

1985-12-26

497

Cryogenic refrigeration, volume 2. A bibliography with abstracts  

Microsoft Academic Search

Cryogenic cooling of electronic equipment, infrared equipment, infrared equipment, cryogenic storage vessels, magnetohydrodynamic generators, and superconducting magnets, coils, rotating machinery, and transmission lines is reported. Marine refrigeration of liquefied natural gas, cryogenic heat pipes, cryogenic heat transfer, and space applications are studied. Methods investigated include adiabatic demagnetization, electrocaloric effect, Joule-Thompson effect, thermoelectric cooling, and Crayton, Claude, Gifford-McMahon, Sterling, and Vuilleumier

W. E. Reed

1978-01-01

498

Cryogenic refrigeration, volume 3. A bibliography with abstracts  

Microsoft Academic Search

Cryogenic cooling of electronic equipment, infrared equipment, cryogenic storage vessels, magnetohydrodynamic generators, and superconducting magnets, coils, rotating machinery, and transmission lines is reported. Marine refrigeration of liquefied natural gas, cryogenic heat pipes, cryogenic heat transfer, and space applications are studied. Methods investigated include adiabatic demagnetization, electrocaloric effect, Joule-Thomson effect, thermoelectric cooling, and Crayton, Claude, Gifford-McMahon, Sterling, and Vuilleumier cycles. This

W. E. Reed

1978-01-01

499

Cryogenic refrigeration, volume 3. A bibliography with abstracts  

Microsoft Academic Search

Topics in the cited reports include cryogenic cooling of electronic equipment, infrared equipment, cryogenic storage vessels, magnetohydrodynamic generators, and superconducting magnets, coils, rotating machinery, and transmission lines. Marine refrigeration of liquefied natural gas, cryogenic heat pipes, cryogenic heat transfer, and space applications are studied. Methods investigated include adiabatic demagnetization, electrocaloric effect, Joule-Thomson effect, thermoelectric cooling, and Crayton, Claude, Gifford-McMahon, Sterling,

W. E. Reed

1979-01-01

500

Future perspectives of using hollow fibers as structured packings in light hydrocarbon distillation  

SciTech Connect

Olefin and paraffin are the largest chemical commodities. Furthermore, they are major building blocks for the petrochemical industry. Each year, petroleum refining, consumes 4,500 TBtu/yr in separation energy, making it one of the most energy-intensive industries in the United States). Just considering liquefied petroleum gas (ethane/propane/butane) and olefins (ethylene and propylene) alone, the distillation energy consumption is about 400 TBtu/yr in the US. Since petroleum distillation is a mature technology, incremental improvements in column/tray design will only provide a few percent improvements in the performance. However, each percent saving in net energy use amounts to savings of 10 TBtu/yr and reduces CO{sub 2} emissions by 0.2 MTon/yr. In practice, distillation columns require 100 to 200 trays to achieve the desired separation. The height of a transfer unit (HTU) of conventional packings is typical in the range of 36-60 inch. Since 2006, we had explored using several non-selective membranes as the structured packings to replace the conventional packing materials used in propane and propylene distillation. We obtained the lowest HTU of < 8 inch for the hollow fiber column, which was >5 times shorter than that of the conventional packing materials. In 2008, we also investigated this type of packing materials in iso-/n-butane distillation. Because of a slightly larger relative volatility of iso-/n-butane than that of propane/propylene, a wider and a more stable operational range was obtained for the iso-/n-butane pair. However, all of the experiments were conducted on a small scale with flowrate of < 25 gram/min. Recently, we demonstrated this technology on a larger scale (<250 gram/min). Within the loading range of F-factor < 2.2 Pa{sup 0.5}, a pressure drop on the vapor side is below 50 mbar/m, which suggests that the pressure drop of hollow fibers packings is not an engineering barrier for the applications in distillations. The thermal stability study suggests that polypropylene hollow fibers are stable after a long time exposure to C{sub 2} - C{sub 4} mixtures. The effects of packing density on the separation efficiency will be discussed.

Yang, Dali [Los Alamos National Laboratory; Orler, Bruce [Los Alamos National Laboratory; Tornga, Stephanie [Los Alamos National Laboratory; Welch, Cindy [Los Alamos National Laboratory

2011-01-26