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1

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

2

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

3

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

4

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

5

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

6

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

7

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

8

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

9

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

10

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

11

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

12

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

13

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

14

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

15

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

16

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

17

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

18

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

19

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

20

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

21

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

22

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

23

Simulation, design, and analysis of azeotropic distillation operations  

Microsoft Academic Search

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,

Bjarne S. Bossen; Sten Bay Joergensen; Rafiqul Gani

1993-01-01

24

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

25

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

26

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

27

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

28

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

29

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

30

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

31

A general approach to generate distillation regions for azeotropic and heteroazeotropic multicomponent mixtures  

Microsoft Academic Search

The aim of this paper is to show how distillation boundaries can determined. The method developed in this paper can be applied to azeotropic, heteroazeotropic or reactive distillation. Our article is composed of three principal sections, each describing an essential step enabling us to built the distillation maps: determination of the azeotropes, as a function of the temperature and composition,

M. Meyer; J. M. Reneaume; J. M. Lelann

1999-01-01

32

ANALYSIS OF AZEOTROPIC DISTILLATION SEQUENCES START UP  

Microsoft Academic Search

The optimal start-up of a two-distillation tower process involving multiple steady states is a very complex task, since a rigorous dynamic optimization is necessary. Searching for optimal start-up strategies for tower sequences is far from trivial. Besides of the multiplicity of solutions, one of the complicating factors is the activation of the recycle stream, which severely constrains the possible start-up

Nicolás J. Scenna; Sonia J. Benz; Nestor H. Rodríguez; Juan Ignacio Klaric

33

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

34

Hetero-azeotropic distillation: combining fungal dehydration and lipid extraction.  

PubMed

A low-cost single-stage laboratory process combining fungal dehydration and lipid extraction was compared with a traditional two-stage method employing freeze-drying and subsequent mechanical disruption in the presence of solvent. The ability of a number of organic solvents to form hetero-azeotropes with water was exploited. Chloroform, cyclohexane and hexane were assessed in their abilities to both dry and extract lipid from the oleaginous phycomycete Mortierella alpina (ATCC 32222). Drying rate and lipid extraction were maximised under conditions that prevented fungal agglomeration. The total processing time was limited by the rate of dehydration rather than by the rate of lipid extraction. In all cases azeotropic distillation facilitated a greater rate of dehydration than was possible with freeze-drying. A consequent reduction in overall processing time was observed. Uniquely, both the solvent used and the mode of mixing employed controlled the morphology of the aggregates formed during distillation. In combination with mild mixing chloroform discouraged agglomeration whereas cyclohexane and hexane promoted aggregation. Successful lipid extraction was dependent on the use of dry biomass rather than on the application of heat to effect distillation. Neither the application of heat nor the solvent employed had any significant effect on the lipid composition of the extracted oil. PMID:16232815

Tough, A J; Isabella, B L; Beattie, J E; Herbert, R A

2000-01-01

35

Synthesizing alternative sequences via a P-graph-based approach in azeotropic distillation systems  

Microsoft Academic Search

The present work proposes a P-graph based approach capable of systematically generating all combinatorially feasible alternative sequences for both continuous and batch azeotropic distillation systems when the feeds, products, and operating units and their concomitant intermediate materials are known. To facilitate synthesis, a highly effective method has been established to identify processing or operating units necessary for constructing azeotropic-distillation systems

Gangyi Feng; L. T. Fan; F. Friedler

2000-01-01

36

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

37

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

38

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

39

Optimization study on the azeotropic distillation process for isopropyl alcohol dehydration  

Microsoft Academic Search

Modeling and optimization work was performed using benzene as an entrainer to obtain a nearly pure anhydrous isopropyl alcohol\\u000a product from dilute aqueous IPA mixture through an azeotropic distillation process. NRTL liquid activity coefficient model\\u000a and PRO\\/II with PROVISION 6.01, a commercial process simulator, were used to simulate the overall azeotropic distillation\\u000a process. We determined the total reboiler heat duties

Jungho Cho; Jong-Ki Jeon

2006-01-01

40

Modeling and simulation of azeotropic distillation for chloroform (1) + methanol (2) + acetone (3)  

Microsoft Academic Search

Azeotropic distillation is a special case of multicomponent distillation used for separation of binary mixtures which are either difficult or impossible to separate by ordinary fractionation. It is commonly used to separate close boiling mixtures with far fewer trays than in conventional distillation and with less circulation, resulting in lower equipment and energy costs. It is widely used for the

D. Krishna; G Santhosh Kumar

2012-01-01

41

The Influence of Distillation Conditions on the Azeotropic Composition  

Microsoft Academic Search

The thermodynamic conditions that determine the presence of an azeotrope in a binary solution are developed and analyzed together with the criteria that define if the azeotrope has a maximum or minimum boiling point at constant pressure. It is shown that using simple models for describing vapor-liquid equilibria and vapor pressure data of the pure components it is possible to

Jaime Wisniak

1998-01-01

42

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

43

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

44

Minimising environmental impact using CBR: an azeotropic distillation case study  

Microsoft Academic Search

This paper describes a Case Based Reasoning (CBR) system which aids the design of process sequences aimed at the separation of ternary mixtures containing azeotropes. The solution of such tasks is a non-trivial process particularly since many factors including environmental impact must be considered. CBR is an appropriate technique for design since it is rare that a completely new problem

Josh M. P. King; René Bañares-alcántara; Zainuddin A. Manan

1999-01-01

45

Optimal design and synthesis of homogeneous azeotropic distillation sequences  

Microsoft Academic Search

A systematic procedure for optimizing homogeneous azeotropic separation sequences has been developed. The procedure uses an explicit design technique which eliminates the need for recycle convergence schemes. The separation of ethanol from water using ethylene glycol as the entrainer is used to illustrate the optimization procedure. Comparisons are made with competing designs from the literature, illustrating the need to properly

Jennifer R. Knight; Michael F. Doherty

1989-01-01

46

Design and control of acetic acid dehydration system via heterogeneous azeotropic distillation  

Microsoft Academic Search

Acetic acid dehydration is an important operation in the production of aromatic acid, such as terephthalic acid or in the manufacture of cellulose acetate. Although acetic acid and water does not form azeotrope, but using simple distillation to separate these two components is not practical. The reason is because the system has tangent pinch on the pure water end, thus

I. Lung Chien; Kai-Luen Zeng; Huan-Yi Chao; Jun Hong Liu

2004-01-01

47

Novel azeotropic distillation process for synthesizing nanoscale powders of yttria doped ceria electrolyte  

Microsoft Academic Search

Nanoscale yttria doped ceria powder was successfully synthesized by azeotropic distillation process, which effectively dehydrated hydrous ceria and completely prevented the formation of hard agglomerates. After being calcined at 500°C for 2 h, the average powder size was less than 10 nm. Powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and Raman spectroscopy were performed to characterize the powder properties.

Shaowu Zha; Qingxi Fu; Yin Lang; Changrong Xia; Guangyao Meng

2001-01-01

48

Systematic Generation of the Optimal and Alternative Flowsheets for Azeotropic-Distillation Systems  

Microsoft Academic Search

A systematic and rigorous method for synthesizing azeotropic-distillation systems, which is of utmost practical importance, is yet to be fully established. The available methods are based mainly on heuristics and graphical procedures. Our experience indicates that even in synthesizing a simple separation network, the structure of the optimal solution may be counterintuitive. For synthesizing a complex network structure necessary for

G. Fengb Friedler; L. T. Fan

49

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

50

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

51

Effects of Ultrasonic Waves on Vapor-Liquid Equilibrium of an Azeotropic Mixture  

Microsoft Academic Search

Azeotropic and extractive distillation techniques used to separate azeotropic mixtures are among the most challenging separation processes in the chemical industry. In this work, an innovative distillation technique which employed ultrasonic waves was proposed to intensify the conventional multi-column azeotropic distillation method into a single-column alternative. The effects of ultrasonic intensity on the vapor-liquid equilibrium (VLE) of methyl-tert-butyl-ether (MTBE)-methanol was

Adnan Ripin; Siti Kholijah Abdul Mudalip; Zairina Sukaimi; Rosli Mohd Yunus; Zainuddin Abdul Manan

2009-01-01

52

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

53

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

54

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

55

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

56

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

57

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

58

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

59

Separation of azeotropic mixture by a biopolymer, chitin  

Microsoft Academic Search

The azeotropic mixture cannot be separated by the general distillation method. A biopolymer, chitin, packed into the straight glass column has been found to be able to separate various kinds of azeotropic mixtures at room temperature and under 1atm. The azeotropic mixtures such as cyclohexane–butanol, acetone–methanol, cyclohexane–acetone, ethyl acetate–methanol, benzene–ethanol, toluene–methanol etc., can be separated to obtain 100% pure main

Li-Yi Chen; Ji-Chao Zhang; Nan Wang; Mei-Yu Huang; Ying-Yan Jiang

2005-01-01

60

Azeotropic data for binary and ternary systems at moderate pressures  

Microsoft Academic Search

For the synthesis and design of distillation columns the knowledge of azeotropic points is most important. Therefore, a computerized data bank for azeotropic data has been established at the University of Oldenburg to supplement the existing mixture information stored in the Dortmund Data Bank. To check questionable literature data and to extend the contents of the computerized data bank, more

Jürgen Gmehling; R. Boelts

1996-01-01

61

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

62

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

63

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

64

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

65

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

66

Discovery of a reactive azeotrope  

Microsoft Academic Search

Mixtures are azeotropic if they can be distilled (or condensed) without a change of composition. The existence of azeotropes in multicomponent mixtures in the absence of chemical reactions is well understood phenomenologically, and theoretically,. Azeotropes place a fundamental limit on the compositions attainable in mixtures by fractional distillation, but they can in some cases be `broken' by carrying out chemical

W. Song; R. S. Huss; M. F. Doherty; M. F. Malone

1997-01-01

67

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

68

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

69

Azeotropic data for binary and ternary systems at moderate pressures  

SciTech Connect

For the synthesis and design of distillation columns the knowledge of azeotropic points is most important. Therefore, a computerized data bank for azeotropic data has been established at the University of Oldenburg to supplement the existing mixture information stored in the Dortmund Data Bank. To check questionable literature data and to extend the contents of the computerized data bank, more than 500 azeotropic and zeotropic data for binary and ternary systems have been measured up to pressures of 3.5 bar with the help of a wire band column. A total of 38 binary azeotropic and zeotropic data for various ethers (MTBE, TAME, TAEE, ETBE, IPTBE) with different alcohols have already been published (Gmehling et al., 1995). A total of 273 binary and 28 ternary azeotropic and zeotropic data are reported in this paper.

Gmehling, J.; Boelts, R. [Univ. Oldenburg (Germany)

1996-03-01

70

The forms of azeotropic rule for multidimensional diagrams of equilibrium distillation  

NASA Astrophysics Data System (ADS)

Linear independent forms of the azeotropy rule applicable to diagrams of distillation (reaction distillation) and their fragments are established and presented as simple polyhedra of arbitrary dimensions.

Pisarenko, Yu. A.; Usol'tseva, O. O.; Cardona, C. A.; Gerard, O. T.

2013-09-01

71

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

72

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

73

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

74

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

75

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

76

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

77

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

78

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

79

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

80

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

81

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

82

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

83

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

84

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

85

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

86

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

87

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

88

Multiperiod design of azeotropic separation systems II: approximate models  

Microsoft Academic Search

In this paper, the final in a two part series considering the multiperiod design of azeotropic separation systems, we focus on the development of simplified models for azeotropic distillation design. Several shortcut design techniques from the literature are reviewed and key aspects of a successful model for use in multiperiod azeotropic distillation design are identified. Simplified models for azeotropic design

K. H Tyner; A. W Westerberg

2001-01-01

89

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

90

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

91

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

92

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

93

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

94

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

95

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

96

Design and Synthesis Procedure for Homogeneous and Heterogeneous Azeotropic Distillations: Final Report, March 1, 1985-February 29, 1988.  

National Technical Information Service (NTIS)

New design and synthesis techniques have been developed for two types of complex multicomponent distillation systems; heterogeneous distillations, and reactive distillations. The concepts of residue curve maps and distillation boundaries have been extende...

M. F. Doherty

1988-01-01

97

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

98

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

99

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

100

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

101

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

102

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

103

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

104

THE SEPARATION OF HYDROGEN ISOTOPES BY DISTILLATION OF AZEOTROPIC MIXTURES OF STRONG ACIDS WITH WATER. III. THE TEMPERATURE DEPENDENCE OF THE ELEMENTARY SEPARATION FACTOR FOR THE AZEOTROPE NITRIC ACID-WATER  

Microsoft Academic Search

Because of the contribution of the isotopic exchange equilibria, a large ; separation parameter delta = alpha - 1 = (D\\/H)\\/sub steam\\/\\/(D\\/H)\\/sub liquid\\/ - ; 1 is to be expected for the distribution of hydrogen rsotopes between liquid ; azeotropic mixtures of strong acids with water and their vapor. In the case of ; azeotropic nitric acid, delta = 0.059,

K. Wetzel; H. Schuetze; G. Kretzschmann

1962-01-01

105

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

106

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

107

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

108

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

109

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

110

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

111

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

112

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

113

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

114

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

115

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

116

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

117

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

118

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

119

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

120

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

121

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

122

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

123

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

124

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

125

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

126

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

127

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

128

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

129

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

130

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

131

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

132

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

133

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

134

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

135

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

136

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

137

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

138

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

139

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

140

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

141

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

142

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

143

Application of azeotropic mixtures as standards in testing gas chromatographic systems and components  

Microsoft Academic Search

Summary  The use of specially chosen azeotropes is proposed as standards when testing gas chromatographs, detectors, columns and sample introduction systems. These azeotropic mixtures permit us to minimize the errors due to composition changes during sampling and sample introduction systems (intended for gases or liquids). The potentialities and advantages of such applications are illustrated using the azeotropic mixture of benzene and

B. V. Ioffe; A. G. Vitenberg; A. N. Marinichev; L. M. Kuznetsova

1976-01-01

144

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

145

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

146

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

147

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

148

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

149

Locating all azeotropes in homogeneous azeotropic systems  

Microsoft Academic Search

A global optimization based approach for finding all homogeneous azeotropes in multicomponent mixtures is presented. The global optimization approach is based on a branch and bound framework in which upper and lower bounds on the solution are refined by successively partitioning the target region into small disjoint rectangles. The objective of such an approach is to locate all global minima

C. D. Maranas; C. M. McDonald; S. T. Harding; C. A. Floudas

1996-01-01

150

Azeotropic phase equilibrium diagrams: a survey  

Microsoft Academic Search

An analysis of the structural properties of vapor–liquid equilibrium (VLE) diagrams provides a fundamental understanding of the thermodynamic behavior of azeotropic mixtures upon distillation.In addition to a review of well-known fundamental work on the analysis of VLE diagrams, this survey comprises less-known published results, especially from the Russian literature. Some new results are also presented for the first time.

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

2003-01-01

151

Review Azeotropic phase equilibrium diagrams: a survey  

Microsoft Academic Search

An analysis of the structural properties of vapor-liquid equilibrium (VLE) diagrams provides a fundamental understanding of the thermodynamic behavior of azeotropic mixtures upon distillation. In addition to a review of well-known fundamental work on the analysis of VLE diagrams, this survey comprises less-known published results, especially from the Russian literature. Some new results are also presented for the 6rst time.

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

152

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

153

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

154

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

155

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

156

Electroosmotic Membrane Pump for the separation of water from azeotropic mixtures. Technical progress report, Phase 1  

SciTech Connect

The Electroosmotic Membrane (EOM) Pump is proposed as a process for saving energy during the separation of azeotropes of alcohol and water. The process is electrically driven and removes water from the process stream through ion-selective membranes by electroosmosis. A laboratory-scale Model Cell was constructed to test the EOM pump concept using commercially available ion exchange membranes. Tests were performed with the Model Cell at various (1) alcohol-water compositions, (2) feed molalities of lithium chloride and lithium bromide in water, (3) stack temperatures, and (4) other operating conditions, such as stack configuration and membrane thickness. As part of the integration of the EOM pump and distillation processes, the effect of salt injection into the reflux line of the distillation column was studied. A conclusion of the study is that the overhead composition can be substantially enriched in alcohol to essentially anhydrous alcohol with salt addition.

Lundstrom, J.E.

1986-03-01

157

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

158

Reliable computation of homogeneous azeotropes  

Microsoft Academic Search

It is important to determine the existence and composition of homogeneous azeotropes in the analysis of phase behavior and in the synthesis and design of separation systems, from both theoretical and practical standpoints. A new method for reliably locating any and all homogeneous azeotropes for multicomponent mixtures is presented. The method also verifies the nonexistence of homogeneous azeotropes if none

Robert W. Maier; Joan F. Brennecke; Mark A. Stadtherr

1998-01-01

159

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

Microsoft Academic Search

In industrial practice the separation of an azeotropic mixture usually involves adding a third component to the distillation process to break the azeotrope. The major disadvantages of this so called azeotropic and extractive distillation are the relatively high capital and high energy costs and the possibility of product contamination.\\u000aA rather new alternative for breaking azeotropes and a fine example

P. Perez

2007-01-01

160

A new way of separating azeotropic mixtures in batch rectifier  

Microsoft Academic Search

Separation of a maximum boiling azeotrope (chloroform \\/ ethyl acetate) with intermediate boiling entrainer (2-chlorobutane) in batch rectifier is studied in this paper with a new configuration variant (IBED) of batch extractive distillation (BED). Feasibility study is performed, then the two configurations are compared on the basis of theoretical considerations, short-cut estimations, and rigorous simulations. More than 20 % of

C. Steger; Z. Lelkes; E. Rev; M. Meyer; Z. Fonyo

2004-01-01

161

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

162

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

163

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.

164

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.

165

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

166

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

167

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

168

Reliable computation of reactive azeotropes  

Microsoft Academic Search

The determination of the existence and composition of reactive azeotropes is important from both theoretical and practical standpoints in the analysis of combined reaction and phase equilibrium and in the synthesis and design of reactive separation systems. We present here a new method for reliably locating, from given thermodynamic models, any and all reactive azeotropes for multicomponent mixtures. The method

Robert W. Maier; Joan F. Brennecke; Mark A. Stadtherr

2000-01-01

169

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

170

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

171

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

172

Reliable computation of homogeneous azeotropes  

SciTech Connect

It is important to determine the existence and composition of homogeneous azeotropes in the analysis of phase behavior and in the synthesis and design of separation systems, from both theoretical and practical standpoints. A new method for reliably locating any and all homogeneous azeotropes for multicomponent mixtures is presented. The method also verifies the nonexistence of homogeneous azeotropes if none are present. The method is based on interval analysis, in particular an interval-Newton/generalized-bisection-algorithm providing a mathematical and computational guarantee that all azeotropes are located. This general-purpose technique can be applied in connection with any thermodynamic models. The technique is illustrated in several example problems using the Wilson, NRTL, and UNIQUAC activity-coefficient models.

Maier, R.W.; Brennecke, J.F.; Stadtherr, M.A. [Univ. of Notre Dame, IN (United States). Dept. of Chemical Engineering

1998-08-01

173

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

174

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

175

Synthesis, experiments and simulation of heterogeneous batch distillation processes  

Microsoft Academic Search

The presence of azeotropes in multicomponent mixtures complicates the design of batch distillation separation processes widely used in pharmaceutical and speciality chemical industries. Most of those processes include the use of a homogeneous entrainer to ease the separation. We describe novel methods to break azeotropes using an entrainer that is partially miscible with one of the initial binary mixture components.

I Rodriguez-Donis; E Pardillo-Fontdevila; V Gerbaud; X Joulia

2001-01-01

176

Synthesis, experiments and simulation of heterogeneous batch distillation processes  

Microsoft Academic Search

The presence of azeotropes in multicomponent mixtures complicates the design of batch distillation separation processes widely used in pharmaceutical and speciality chemical industries. Most of those processes include the use of a homogeneous entrainer to ease the separation. We describe novel methods to break azeotropes using an entrainer that is partially miscible with one of the initial binary mixture components.

I. Rodriguez-Donis; E. Pardillo-Fontdevila; V. Gerbaud; X. Joulia

177

Temperature sequences for categorizing all ternary distillation boundary maps  

Microsoft Academic Search

Temperature sequences are formulated as a complete method of categorizing the feasible distillation boundary maps (DBMs) for ternary systems which commonly have unique binary and ternary azeotropes. DBMs are simplified versions of residue curve maps. The method requires the boiling temperatures at system pressure of pure components and azeotropes, if they exist. Seven position numbers are assigned to the pure

Eric J. Peterson; Lee R. Partin

1997-01-01

178

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

179

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

180

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

181

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

182

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

183

Expert system for the design of separation sequences for close-boiling and azeotropic mixtures  

SciTech Connect

Formation of azeotropes, or occurrence of close boiling components in a mixture, precludes straightforward rectification as a method of separation. Instead, recourse must be taken to special distillation processes which overcome distillation boundaries by the admixture of an entrainer or solvent, or by exploitation of inherent system properties. While the choice of a suitable entrainer is almost the only important factor in the design of extractive rectification processes, to sort out the numerous possible variants is difficult, due to the different distillation properties of the azeotropic mixture. A satisfactory approach is offered by the use of heuristic knowledge in the form of a knowledge-based expert system to provide alternatives which correspond to the requirements of the process. Starting with a small amount of readily available physical property data for pure components and mixtures, rectification processes which are suitable for the separation of a close boiling or an azeotropic mixture are selected, and appropriate process structures are generated. The expert proposes entrainers, meeting the demands of the process under consideration. The present paper presents a detailed description of the structure and the operation of the expert system for selecting entrainers and for process generation. The system consists of modules for pressure change, homoazeotropic, heteroazeotropic, extractive, and multiple azeotropic rectification, procedural strategy, and explanatory components.

Simmrock, K.H. [Univ. Dortmund (Germany). Lehrstuhl fuer Technische Chemie; Fried, A.; Welker, R. [BASF AG, Ludwigshafen (Germany)

1993-10-01

184

AZEOTROPE PREDICTION BY MONTE CARLO MOLECULAR SIMULATION  

Microsoft Academic Search

This article presents a methodology for checking the existence of the azeotrope and computing its composition, density, and pressure at a given temperature by integrating chemical engineering insights with molecular simulation principles. Liquid-vapor equilibrium points are computed by molecular simulations using the Gibbs ensemble Monte Carlo (GEMC) method at constant volume. The appearance of the azeotropic point is marked by

M. K. Hadj-Kali; V. Gerbaud; X. Joulia

2012-01-01

185

Computing heterogeneous azeotropes in multicomponent mixtures  

Microsoft Academic Search

A fundamental approach to the calculation of homogeneous azeotropes of multicomponent mixtures was published by Fidkowski et al. (1993) [Fidkowski et al., Computers Chem Engng17, 1141 (1983)] recently. This paper is a generalization of that approach for cases where multiple liquid phases can coexist in equilibrium (heterogeneous azeotropes). An example for the mixture ethanol-water-cyclohexane-benzene is presented.

E. Eckert; M. Kubí?ek

1996-01-01

186

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

187

Prediction of azeotropic behavior using equations of state  

Microsoft Academic Search

A shortcut method is developed to determine if an equation of state (EOS) is capable of predicting azeotropes in binary systems and if the azeotrope meets the critical gas–liquid equilibrium line. The method suggested allows an a priori prediction of subcritical azeotropes and an exact prediction of the azeotropic point (if any) at critical conditions. In addition, the approach developed

Hugo Segura; Jaime Wisniak; Pedro G. Toledo; Andrés Mej??a

1999-01-01

188

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

189

Solution multiplicity in multicomponent distillation a computational study  

Microsoft Academic Search

Rigorous models of staged distillation processes are formulated by setting up material balance equations, equilibrium relations, summation equations, and enthalpy balance equations (MESH equations). In these models, the extent of nonlinearity may be very severe, particularly for azeotropic and reactive distillation systems. MESH system based mathematical models can thus yield multiple solutions (multiple steady states), a fact which has been

Nirav M. Dalal; Ranjan K. Malik

2003-01-01

190

Vacuum Distillation of Ethanol. Final Report.  

National Technical Information Service (NTIS)

The objective was to determine whether distillation at or below a pressure of 70 mm of Hg would produce ethanol sufficiently anhydrous to permit mixing with gasoline without separation. The reason for this is that below 70 mm of Hg, the azeotrope does not...

T. V. Weber

1982-01-01

191

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

192

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

193

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

194

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

195

Feasible separations and entrainer selection rules for heteroazeotropic batch distillation  

Microsoft Academic Search

A feasibility analysis is presented for the separation of close-boiling and azeotropic (minimum- and maximum-boiling) binary mixtures into pure components by the addition of an entrainer introducing a heterogeneous azeotrope. The analysis is done for both the conventional batch rectifier and the multivessel batch column. The analysis is theoretical and based on the assumptions of total reflux\\/reboil ratios and infinite

S. Skouras; V. Kiva; S. Skogestad

2005-01-01

196

Locating All Homogeneous Azeotropes in Multicomponent Mixtures  

Microsoft Academic Search

A novel approach for enclosing all homogeneous azeotropes in multicomponent mixturesis presented. The thermodynamic criteria for azeotropy are outlined, and mathematicalequations for each criterion are developed. The global optimization approach isbased on developing convex underestimators which are coupled with a branch and boundframework in which upper and lower bounds on the solution are refined by successivelypartitioning the target region into

S. T. Harding; C. D. Maranas; C. M. McDonald; C. A. Floudas

1997-01-01

197

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

198

Short-cut design of batch extractive distillation using MINLP  

Microsoft Academic Search

An automatic design method for batch extractive distillation, one of the most important techniques for separating low relative volatility or azeotropic mixtures, is presented. Example calculations are performed to the acetone-methanol mixture using water as entrainer. The NLP and MINLP problems are solved with applying GAMS DICOPT++.

Z. Lelkes; Z. Szitkai; T. Farkas; E. Rev; Z. Fonyo

2003-01-01

199

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

200

Energy-saving distillation designs in ethanol production  

Microsoft Academic Search

A thorough study is made of energy-saving options for the distillation of a dilute, aqueous ethanol solution to produce a distillate close to the azeotrope composition. Although presented in the context of a fermentation ethanol plant, the system may be taken as a generic example of a dilute solution with highly nonideal vapor-liquid equilibrium behavior. Conventional energy-saving techniques, such as

Michael A. Collura; William L. Luyben

1988-01-01

201

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

202

Evaluation of a locus of azeotropes by molecular simulation  

SciTech Connect

The technique proposed here for the evaluation of azeotrope lines by molecular simulation builds on ideas used to devise the Gibbs-Duhem integration (GDI) technique for evaluating phase equilibria by molecular simulation. Beginning with a known azeotropic state point, the method integrates a differential equation for the locus of azeotropes with a single semigrand-ensemble molecular simulation performed at each integration state point. Unlike the standard GDI method, fluctuation quantities are needed to conduct the integration. Although these quantities are measured less precisely than simple ensemble averages, the integration is not adversely affected by this difficulty. The method is demonstrated by applying to three model Lennard-Hones binaries. Among these mixtures in one in which the molecular diameter o one species is varied along the azeotrope line. This application shows how details of the intermolecular interactions affect azeotropic behavior. Such an understanding might be useful in formulating additives to break an azeotrope.

Pandit, S.P.; Kofke, D.A.

1999-10-01

203

Spectra and structure of binary azeotropes I. Acetone-chloroform.  

PubMed

Some characteristic vibrational modes of acetone and chloroform change due to the azeotrope formation. The extend of interaction of these molecules has significant effects on some vibrational modes involved, depending on unit structure in azeotrope cluster. Besides (1)H NMR signals undergo some chemical shifts, which show the effect of oncoming molecules on the target molecule. FT-IR and (1)H NMR spectra of pure substances and corresponding azeotrope were recorded, mutual influences due to azeotrope formation based on mole ratio, boiling point and spectral changes has been discussed. Unit structure of cluster deduced by investigating fundamental frequency shifts and (1)H NMR chemical shifts. PMID:16257732

Jalilian, M R; Alibabaei, L

2005-11-01

204

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

205

Rapid screening of regular and thermally coupled design alternatives for nonideal multiproduct distillation processes  

Microsoft Academic Search

A shortcut design method for the separation of nonideal zeotropic and azeotropic mixtures in complex column sequences with and without energy integration is presented. It is based on the decomposition of the process into sequences of simple columns. The minimum energy demand of each column is determined using the rectification body method (RBM). Application of the design method allows rapid

S. Brüggemann; W. Marquardt

2003-01-01

206

Simultaneous Design of Ionic Liquids and Azeotropic Separation Processes  

Microsoft Academic Search

A methodology for the design of azeotrope separation processes using ionic liquids as entrainers is outlined. A Hildebrand solubility parameter group contribution model has been developed to screen for or design an ionic liquid entrainer that is soluble with the azeotropic components. Using the best candidate, vapor-liquid equilibria data is predicted using a new ionic liquid UNIFAC model that has

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

2011-01-01

207

Calculation of a double reactive azeotrope using stochastic optimization approaches  

NASA Astrophysics Data System (ADS)

An homogeneous reactive azeotrope is a thermodynamic coexistence condition of two phases under chemical and phase equilibrium, where compositions of both phases (in the Ung-Doherty sense) are equal. This kind of nonlinear phenomenon arises from real world situations and has applications in chemical and petrochemical industries. The modeling of reactive azeotrope calculation is represented by a nonlinear algebraic system with phase equilibrium, chemical equilibrium and azeotropy equations. This nonlinear system can exhibit more than one solution, corresponding to a double reactive azeotrope. The robust calculation of reactive azeotropes can be conducted by several approaches, such as interval-Newton/generalized bisection algorithms and hybrid stochastic-deterministic frameworks. In this paper, we investigate the numerical aspects of the calculation of reactive azeotropes using two metaheuristics: the Luus-Jaakola adaptive random search and the Firefly algorithm. Moreover, we present results for a system (with industrial interest) with more than one azeotrope, the system isobutene/methanol/methyl-tert-butyl-ether (MTBE). We present convergence patterns for both algorithms, illustrating - in a bidimensional subdomain - the identification of reactive azeotropes. A strategy for calculation of multiple roots in nonlinear systems is also applied. The results indicate that both algorithms are suitable and robust when applied to reactive azeotrope calculations for this "challenging" nonlinear system.

Mendes Platt, Gustavo; Pinheiro Domingos, Roberto; Oliveira de Andrade, Matheus

2013-02-01

208

Azeotropic-like (congruent melting) phenomena of lamellar liquid crystals  

Microsoft Academic Search

The binary system of water and didecyldimethylammonium bromide (DDeAB), having a double hydrocarbon chain, was found to exhibit exhibit an azeotropic-like phase transition from lamellar liquid crystal to micellar solution. That is, the maximum limiting value of temperatures where the present system is allowed to exist in a lamellar liquid crystal corresponds to the socalled azeotropic point (AZP) or congruent

H. Kuniedal; H. Itol; S. Takebayashi; M. Kodama

1993-01-01

209

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

210

New extractive configuration separating azeotropic mixture in semi-batch way  

Microsoft Academic Search

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

Csaba Stéger; Endre Rév; László Horváth; Zsolt Fonyó; Michel Meyer; Zoltán Lelkes

2006-01-01

211

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

212

Temperature sequences for categorizing all ternary distillation boundary maps  

SciTech Connect

Temperature sequences are formulated as a complete method of categorizing the feasible distillation boundary maps (DBMs) for ternary systems which commonly have unique binary and ternary azeotropes. DBMs are simplified versions of residue curve maps. The method requires the boiling temperatures at system pressure of pure components and azeotropes, if they exist. Seven position numbers are assigned to the pure components (three) and azeotropes (three binary, one ternary). The boiling temperatures are sorted to rank the position numbers. The temperature sequence is defined as the ranking of position numbers. The position numbers of missing azeotropes are excluded from the sequence. An algorithm searches all possible temperature sequences for feasible DBMs. The result is a complete listing of 125 DBMs, 307 temperature sequences, and 382 [temperature sequence, DBM] pairs. Lookup tables simplify the procedure for finding the DBM(s) for a temperature sequence or finding the temperature sequences for a DBM. Example applications are presented for applying the technique in the initial screening for distillation system synthesis.

Peterson, E.J.; Partin, L.R. [Eastman Chemical Co., Kingsport, TN (United States)

1997-05-01

213

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

214

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

215

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

216

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

217

PREDICTIONS OF AZEOTROPES FORMED FROM FLUORINATED ETHERS, ETHANES, AND PROPANES  

EPA Science Inventory

The paper discusses an evaluation of the potential for azeotrope formation and performance for fluorinated ethers, ethanes, and propanes. (NOTE: The synthesis of new non-chlorinated refrigerants expands the base of alternatives for replacing ozone-depleting chlorofluorocarbons (O...

218

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

219

Solvent Selection for a Reactive and Extractive Distillation Process by Headspace Gas Chromatography  

Microsoft Academic Search

The aim of this study is to determine the best solvent for the transesterification of the methanol and methyl acetate azeotropic mixture with n-butanol using the extractive and reactive distillation technology. A preliminary selection according to heuristics and physical properties was completed. Selectivity at infinite dilution for 40 systems was measured using headspace gas chromatography. This criteria help to cluster

Laureano Jiménez; José Costa-López

2003-01-01

220

Design of entrainer-enhanced reactive distillation for the synthesis of butyl cellosolve acetate  

Microsoft Academic Search

An innovative entrainer-enhanced reactive distillation (RD) process is presented, which aims to the production of high-purity butyl cellosolve acetate from butyl cellosolve and acetic acid via an esterification reaction. This entrainer-enhanced RD process can procure technical advantages from both heterogeneous azeotropic distillation and RD. Solvents such as cyclohexane, ethylene dichloride, toluene, and octane are considered as candidates in this esterification

San-Jang Wang; Hsiao-Ping Huang

2011-01-01

221

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

222

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

223

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

224

Computing all the azeotropes in refrigerant mixtures through equations of state  

Microsoft Academic Search

Azeotropic mixtures of fluorocarbon (FC) and hydro fluorocarbon (HFC) with hydrocarbons are gaining popularity as drop-in substitutes for CFCs and HCFCs. A method to compute all the azeotropes in a refrigerant mixture through the equation of state approach is described. The method allows prediction of all the azeotropes in a refrigerant mixture and is in close agreement with the experimental

Naveed Aslam; Aydin K. Sunol

2004-01-01

225

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

226

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

227

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

228

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

229

The unusual behavior of extractive distillation--reversing the volatility of the acetone-isopropyl ether system  

Microsoft Academic Search

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°C, was distilled off as the overhead from mixtures with acetone, b.p. = 56.2°C, leaving the acetone in the stillpot

Lloyd Berg; An-I Yeh

1985-01-01

230

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

231

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

232

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

233

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

234

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

235

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

236

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

237

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

238

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

239

Application of the QSPR approach to the boiling points of azeotropes.  

PubMed

CODESSA Pro derivative descriptors were calculated for a data set of 426 azeotropic mixtures by the centroid approximation and the weighted-contribution-factor approximation. The two approximations produced almost identical four-descriptor QSPR models relating the structural characteristic of the individual components of azeotropes to the azeotropic boiling points. These models were supported by internal and external validations. The descriptors contributing to the QSPR models are directly related to the three components of the enthalpy (heat) of vaporization. PMID:21449551

Katritzky, Alan R; Stoyanova-Slavova, Iva B; Tämm, Kaido; Tamm, Tarmo; Karelson, Mati

2011-03-30

240

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

241

THERMODYNAMIC EVALUATION OF PREDICTED FLUORINATED ETHER, ETHANE, AND PROPANE AZEOTROPES  

EPA Science Inventory

The paper gives results of thermodynamic analyses, using basic thermophysical property data, to evaluate seven predicted fluorinated ether, ethane, and propane azeotropes: E125/RC270, E125/R134a, E143a/R134, R134a/E143a, E143a/ R152a, R134/R245cb, and R245cb/R227ea. he performanc...

242

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

243

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

244

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

245

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

246

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

247

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

248

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

249

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

250

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

251

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

252

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

253

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

254

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

255

Study to determine the existence of an azeotropic R-22 `drop-in` substitute  

SciTech Connect

The reduction in chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) production and the scheduled phase-out of these ozone depleting refrigerants requires the development and determination of environmentally safe refrigerants for use in heat pumps, water chillers, air conditioners, and refrigerators. Azeotropic mixtures are attractive as alternative refrigerants because they behave very nearly as pure materials. A simple correlative scheme that allows one to judge whether or not an azeotrope is likely in a binary refrigerant mixture is discussed. This paper presents laboratory and computer simulation model evaluation of two of the azeotropic refrigerant mixtures which are identified, HFC-134a (1,1,1,2-tetrafluoroethane) with R-C290 (Propane) and HFC-134a with R-600a (Isobutane), in a generic heat pump apparatus. A third azeotropes mixture, HFC-134a with R-C290 (Cyclopropane) is examined by computer simulation only.

Kim, M.S.; Morrison, G.; Mulroy, W.J.; Didion, D.A.

1996-03-01

256

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

257

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

258

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

259

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

260

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

261

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

262

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

263

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

264

Anthracene + Pyrene Solid Mixtures: Eutectic and Azeotropic Character  

PubMed Central

To better characterize the thermodynamic behavior of a binary polycyclic aromatic hydrocarbon mixture, thermochemical and vapor pressure experiments were used to examine the phase behavior of the anthracene (1) + pyrene (2) system. A solid-liquid phase diagram was mapped for the mixture. A eutectic point occurs at 404 K at x1 = 0.22. A model based on eutectic formation can be used to predict the enthalpy of fusion associated with the mixture. For mixtures that contain x1 < 0.90, the enthalpy of fusion is near that of pure pyrene. This and X-ray diffraction results indicate that mixtures of anthracene and pyrene have pyrene-like crystal structures and energetics until the composition nears that of pure anthracene. Solid-vapor equilibrium studies show that mixtures of anthracene and pyrene form solid azeotropes at x1 of 0.03 and 0.14. Additionally, mixtures at x1 = 0.99 sublime at the vapor pressure of pure anthracene, suggesting that anthracene behavior is not significantly influenced by x2 = 0.01 in the crystal structure.

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

2010-01-01

265

Anthracene + Pyrene Solid Mixtures: Eutectic and Azeotropic Character.  

PubMed

To better characterize the thermodynamic behavior of a binary polycyclic aromatic hydrocarbon mixture, thermochemical and vapor pressure experiments were used to examine the phase behavior of the anthracene (1) + pyrene (2) system. A solid-liquid phase diagram was mapped for the mixture. A eutectic point occurs at 404 K at x(1) = 0.22. A model based on eutectic formation can be used to predict the enthalpy of fusion associated with the mixture. For mixtures that contain x(1) < 0.90, the enthalpy of fusion is near that of pure pyrene. This and X-ray diffraction results indicate that mixtures of anthracene and pyrene have pyrene-like crystal structures and energetics until the composition nears that of pure anthracene. Solid-vapor equilibrium studies show that mixtures of anthracene and pyrene form solid azeotropes at x(1) of 0.03 and 0.14. Additionally, mixtures at x(1) = 0.99 sublime at the vapor pressure of pure anthracene, suggesting that anthracene behavior is not significantly influenced by x(2) = 0.01 in the crystal structure. PMID:21116474

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

2010-09-01

266

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

267

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

268

Effect of kinetics on residue curve maps for reactive distillation  

SciTech Connect

A class of models is derived for studying the effects of chemical kinetics on residue curve maps for reactive distillation. Activity-based rate and phase equilibrium expressions provide an accurate and thermodynamically consistent description of composition changes in nonideal, reacting vapor-liquid mixtures. For certain strategies of operation, which dictate the rate of product removal, the model equations are nonautonomous, leading to unusual dynamic behavior. However, for a certain special product removal policy, the effects of kinetics can be described by a single parameter, the Damkoehler number, which measures the rate of reaction relative to product removal. For small values of the Damkoehler number, the nonreactive simple distillation residue curve map is recovered and the singular points are the pure components and azeotropes in the nonreactive mixture. A bifurcation analysis shows the deformation and, in some cases, the disappearance of these singular points as the Damkoehler number is increased until the equilibrium reactive residue curve map is recovered at large values. A model problem for the reactive distillation of methyl tert-butyl ether from isobutene and methanol is solved.

Venimadhavan, G.; Buzad, G.; Doherty, M.F.; Malone, M.F. (Univ. of Massachusetts, Amherst, MA (United States). Dept. of Chemical Engineering)

1994-11-01

269

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

270

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

271

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

272

ASPECTS OF MULTICOMPONENT MIXTURE SEPARATION IN THE PRESENCE OF SELECTIVE SOLVENTS  

Microsoft Academic Search

The extractive and autoextractive distillation of ternary and quaternary azeotropic solvent mixtures was adopted to demonstrate the relation between the structure of phase diagram of the azeotropic systems and the operating parameters of the extractive distillation column based on the relative volatility criterion. A set of separation schemes belonging to different structural classes have been investigated. The separation scheme that

H. Benyounes; A. K. Frolkova

2010-01-01

273

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

274

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

275

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

276

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

277

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

278

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

279

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

280

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

281

Design of separation process of azeotropic mixtures based on the green chemical principles  

Microsoft Academic Search

This paper presents an integrated methodology for synthesis of separation process of azeotropic mixture based on the green chemical principles, which inherently incorporates environmental factors into the separation process synthesis. Characterization of the environmental impact of a chemical process is carried out on the basis of our established environmental impact database (containing nine indices). The superstructure is optimized more effectively

Chunshan Li; Xiangping Zhang; Xuezhong He; Suojiang Zhang

2007-01-01

282

Thermodynamic Properties of an Azeotropic Freon-22 and Freon-115 Mixture.  

National Technical Information Service (NTIS)

An azeotropic mixt. of Freon-22, 48.8%, and Freon-115, 51.2%, has a b.p. of -45.6C. Its vol. cooling power is considerably higher than that of Freon-12, Freon-22, and Freon-115. This mixt. is neither explosive nor toxic. Two equations for calculating the ...

I. S. Badylkes

1967-01-01

283

Performance of a residential heat pump operating with a non-azeotropic binary refrigerant mixture - an interim report. [R22 vs non-azeotropic binary mixture of R13B1 and R152a  

SciTech Connect

This report presents results of laboratory measurement of the performance change of a substantially unmodified residential heat pump designed for R22 when charged with a non-azeotropic, binary mixture of R13B1 and R152a. Results are presented for various sizes of fixed expansion devices. The effect of gliding temperature in the saturation zone was found to be small. The effect of composition shift by flash distillation in the accumulator was found to measurably improve low temperature heating performance. There appears to be an inherent trade-off when operating an unmodified heat pump with mixtures so as to increase capacity at lower temperatures. This trade-off is that as the evaporator pressure decreases and refrigerant begins to flood through to the accumulator and thus allowing the composition shift to occur, the subcooling on the high pressure side also decreases causing a decrease in the available latent enthalpy difference. A possible solution to this problem might be to increase the amount of initial charge. This would cause on increase in head pressures which could be a problem in the cooling mode. A possible solution to this excessive head pressure problem would be to incorporate a receiver in the system in the branch line just ahead of the expansion device for the outdoor coil. Thus, when this coil is acting as an evaporator (i.e., heating mode) the stored refrigerant would be released into the circulating system allowing for more composition shift to occur. Such a solution will be pursued as one of the items of study during the next phase of this project. 9 refs., 11 figs., 1 tab.

Didion, D.; Mulroy, W.

1984-01-01

284

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

285

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

286

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

287

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

288

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

289

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

290

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

291

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

292

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

293

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

294

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

295

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

296

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

297

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.

298

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

299

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

300

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

301

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

302

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

303

Theory of Phase Diagrams and Azeotropic Conditions for Two-Phase Reactive Systems  

Microsoft Academic Search

Expressions for the partial derivatives of the intensive properties that characterize the equilibrium states in two-phase systems, in which the components undergo one equilibrium chemical reaction, are derived. The necessary and sufficient conditions for an azeotropic transformation to occur are found. It is shown that whereas stationary points in the isobaric temperature-composition or isothermal pressure-composition equilibrium surfaces correspond to the

D. Barbosa; M. F. Doherty

1987-01-01

304

Adsorbate shape selectivity: Separation of the HF\\/134a azeotrope over carbogenic molecular sieve  

Microsoft Academic Search

Experimental evidence is provided for adsorptive shape selectivity in the separation of the azeotrope between HF and 1,1,1,2-tetrafluoroethane (134a) over pyrolyzed poly(furfuryl alcohol)-derived carbogenic molecular sieve (PPFA-CMS). The separation can be accomplished over coconut charcoal or Carbosieve G on the basis of the differences in the extent of equilibrium adsorption of HF and 134a. On these adsorbents 134a is more

Allan Hong; Ravindra K. Mariwala; Michael S. Kane; Henry C. Foley

1995-01-01

305

Development of a process for PCB removal from triaryl phosphate hydraulic fluids by vacuum distillation  

SciTech Connect

A method of separating PCBs (Aroclor 1242) from a triaryl phosphate ester based hydraulic fluid that yields a fluid suitable for reuse in an aluminum die casting foundry was identified in a laboratory study. Experiments were done to determine the separation efficiency and product qualities resulting from the use of vacuum, steam, and azeotropic distillation, solvent extraction, foam fractionation, filtration, and adsorption techniques. Vacuum distillation was found to remove over 98% of the PCBs with recoveries of fluid, containing less than 50 ppm PCBs, of 90% at 5 mmHg vacuum, and 85% at 30 mmHg vacuum. The PCBs (bp 225-365/sup 0/C) were distilled from the hydraulic fluid (bp>400/sup 0/C). The product met industry standards for acid number and viscosity required for reuse. The data needed to design a 5 gallon/min pilot plant for the vacuum distillation of PCBs from hydraulic fluid in storage at an aluminum die casting foundry were also obtained.

Longanbach, J.R.; Mink, W.H.

1983-01-01

306

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

307

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

308

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

309

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

310

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

311

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

312

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

313

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

314

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

315

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

316

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

317

Icke-azeotropa blandningar i vaermepumpar. Foerstudie foer fullskaleprojekt. (Non-azeotropic mixtures in heat pumps. Preliminary study for a full scale project).  

National Technical Information Service (NTIS)

An experimental heat pump with a non-azeotropic mixture as working fluid is being prepared. This will be the first full scale plant in Sweden. The influence of a non-azeotropic mixture, as compared with a pure fluid on the design of the components in the ...

L. Albert T. Berntsson M. Hoegberg L. Persson

1990-01-01

318

Wet compression versus dry compression in heat pumps working with pure refrigerants or non-azeotropic binary mixtures for different heating applications  

Microsoft Academic Search

Wet compression versus dry compression in heat pumps working with pure refrigerants or non-azeotropic binary mixtures is investigated in this paper. In total 34 pure refrigerants as well as 31 non-azeotropic binary mixtures at different concentrations are considered. This resulted in approximately 300 different mixtures being analysed. The pure refrigerants were analysed for three different heating applications found in practice:

P. P. J Vorster; J. P Meyer

2000-01-01

319

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

320

Experimental investigation of moderately high temperature water source heat pump with non-azeotropic refrigerant mixtures  

Microsoft Academic Search

Experimental investigations were carried out on non-azeotropic refrigerant mixtures, named M1A (mass fraction of 20%R152a and 80%R245fa), M1B (mass fraction of 37% R152a and 63%R245fa) and M1C (mass fraction of 50%R152a and 50%R245fa), based on a water-to-water heat pump system in the condensing temperature range of 70–90°C with a cycle temperature lift of 45°C. Performance of R245fa was tested for

Shengjun Zhang; Huaixin Wang; Tao Guo

2010-01-01

321

Heat transfer in pool boiling of binary and ternary non-azeotropic mixtures  

Microsoft Academic Search

Heat transfer coefficients in nucleate pool boiling of binary and ternary non-azeotropic hydrocarbon mixtures were obtained\\u000a experimentally using a vertical electrically heated cylindrical carbon steel surface at atmospheric pressure with several\\u000a surface roughness. The fluids used were Methanol\\/1-Pentanol and Methanol\\/1-Pentanol\\/1,2-Propandiol at constant 1,2-Propandiol\\u000a mole fraction of 30%. Heat fluxes were varied in the range 25–235 kW\\/m2. The cylindrical heater surface was

Ziad Nahra; Erling Næss

2009-01-01

322

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

323

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

324

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

325

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

326

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

327

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

328

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

329

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

330

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

331

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

332

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

333

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

334

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

335

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

336

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

337

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

338

Heat transfer in pool boiling of binary and ternary non-azeotropic mixtures  

NASA Astrophysics Data System (ADS)

Heat transfer coefficients in nucleate pool boiling of binary and ternary non-azeotropic hydrocarbon mixtures were obtained experimentally using a vertical electrically heated cylindrical carbon steel surface at atmospheric pressure with several surface roughness. The fluids used were Methanol/1-Pentanol and Methanol/1-Pentanol/1,2-Propandiol at constant 1,2-Propandiol mole fraction of 30%. Heat fluxes were varied in the range 25-235 kW/m2. The cylindrical heater surface was polished to an average surface roughness of 0.2 ?m, and sandblasted yielding surface roughness of 2.98 and 4.35 ?m, respectively. The experimental results were compared to available prediction correlations, indicating that the correlations based on the boiling range are in better qualitative agreement than correlations based on the phase envelope. Increasing surface roughness resulted in an increase in the heat transfer coefficient, and the effect was observed to be dependent on the heat flux and fluid composition.

Nahra, Ziad; Næss, Erling

2009-05-01

339

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

340

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

341

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

342

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

343

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

344

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

345

Selective Retention of Explosives and Related Compounds on Gas-Chromatographic Capillary Columns Coated with Lanthanide(III) ß-diketonate Polymers  

SciTech Connect

The purpose of this research was to investigate coating capillary columns with lanthanide(III) beta-diketonate polymers to provide gas-chromatographic columns with selectivity toward explosives and related compounds. Capillary columns were statically coated with a combination of a lanthanide(III) beta-diketonate polymer, which utilized p-di(4,4,5,5,6,6,6-heptafluoro-1,3-hexanedionyl)benzene (dihed) as a ligand, and SE-30. A novel coating technique was developed that used a methanol-containing azeotrope to provide solubility for both polymers while maintaining a low boiling point compatible with static coating. As based on temperature-programmed retention indices, the custom experimental columns displayed selective retention of nitroaromatic, nitroalkane, and nitrate ester test probes relative to an appropriate SE-30 control column. Selective retention was more pronounced for strong Lewis base analytes (i.e., cyclohexanone). Relative analyte retention on the La(dihed), Tb(dihed) and Eu(dihed) columns are discussed relative to Lewis acidity and solubility of the polymer in the azeotrope coating solution.

Harvey, Scott D.; Wenzel, Thomas J.

2009-09-04

346

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

347

Study of binary and ternary azeotropes formed by 1,4-butylene glycol and diethylene glycol with alcohols and hydrocarbons  

SciTech Connect

The azeotropic parameters in the 1,4-BG-C/sub 9/C/sub 15/ alcohol series at 13.33 kPa and the DEG-C/sub 9/-C/sub 16/ alcohol series at 2.67 kPa were experimentally determined. Azeotropy was experimentally studied in 14 1,4-BG-alcohol-hydrocarbon ternary systems. It was found that C/sub 8/ and C/sub 15/ alcohols are the alcohols with the lowest and highest molecular weights which form ternary azeotropes with 1,4-BG, and they are C/sub 8/ and C/sub 16/ alcohols for DEG. 1,4-BG is recommended as a separating agent for purification of hydrocarbons from the C/sub 17/-C/sub 20/ fraction of alcohols by the method of heteroazeotropic rectification.

Shleinikova, M.V.; Smirnova, T.N.; Kushner, T.M.

1988-04-10

348

Survey of Binary Azeotropes as Physical Chemistry Lab Experiments with Attention to Cost, Safety, and the Environment  

NASA Astrophysics Data System (ADS)

A survey is presented of possible binary azeotropic systems suitable for study in an undergraduate physical chemistry laboratory. From a range of sources, a list has been compiled of the most acceptable systems on the basis of health, safety, waste disposal, and practicability concerns. More than 80 systems were reviewed. For comparison purposes, the list was reduced to a table showing 5 high-boiling and 19 low-boiling azeotropes with their exposure limits, approximate costs, and some physical properties of the mixtures. Comments are made about the strengths and weaknesses of the choice of each. The paper should supply the instructor with sufficient data to choose a binary system for study and with literature sources for further information.

Glinski, Robert J.; Smith, Christopher W.; Cooke, Jason B.

1999-02-01

349

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

350

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

351

Performance evaluation of two azeotropic refrigerant mixtures of HFC134a with R-290 (propane) and R-600a (isobutane)  

Microsoft Academic Search

The reduction in chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) production and the scheduled phase-out of these ozone-depleting refrigerants require the development and determination of environmentally safe refrigerants for use in heat pumps, water chillers, air conditioners, and refrigerators. This paper presents a performance evaluation of a generic heat pump with two azeotropic refrigerant mixtures of HFC-134a (1,1,1,2-tetrachloroethane) with R-290 (propane) and

M. S. Kim; W. J. Mulroy; D. A. Didion

1994-01-01

352

Performance Simulation and Experimental Testing of Moderately High Temperature Heat Pump Using Non-azeotropic Mixture for Geothermal District Heating  

Microsoft Academic Search

A water-to-water geothermal heat pump is a suitable technology to exploit heat from low-temperature geothermal sources for high-temperature district heating. A distributed parameter model simulation analysis was conducted for the system using non-azeotropic mixture of R245fa and R152a (0.63\\/0.37) under the condition that the input temperature and the flow rate of the heat transfer fluids were provided. The model was

Sheng-jun Zhang; Huai-xin Wang; Tao-guo; Chen Chen

2010-01-01

353

Performance evaluation of two azeotropic refrigerant mixtures of HFC-134a with R-290 (propane) and R-600a (isobutane)  

SciTech Connect

The reduction in chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) production and the scheduled phase-out of these ozone-depleting refrigerants require the development and determination of environmentally safe refrigerants for use in heat pumps, water chillers, air conditioners, and refrigerators. This paper presents a performance evaluation of a generic heat pump with two azeotropic refrigerant mixtures of HFC-134a (1,1,1,2-tetrachloroethane) with R-290 (propane) and R-600a (isobutane); R-290/134a (45/55 by mass percentage) and R-134a/600a (80/20 by mass percentage). The performance characteristics of the azeotropes were compared with pure CFC-12, HFC-134a, HCFC-22, and R-290 at the high temperature cooling and heating conditions including those using liquid-line/suction-line heat exchange. The coefficient of performance of R-290/134a is lower than that of HCFC-22 and R-290, and R-134a/600a shows higher coefficient of performance than CFC-12 and HFC-134a. The capacity for R-290/134a is higher than that for HCFC-22 and R-290, and R-134a/600a exhibits higher system capacity than CFC-12 and HFC-134a. Experimental results show that the discharge temperatures of the studied azeotropic mixtures are lower than those of the pure refrigerants, CFC-12 and HCFC-22.

Kim, M.S.; Mulroy, W.J.; Didion, D.A. (National Inst. of Standards and Technology, Gaithersburg, MD (United States). Building and Fire Research Lab.)

1994-06-01

354

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

PubMed

Classical density functional theory (DFT) was used to predict the adsorption of nine different binary gas mixtures in a heterogeneous BPL activated carbon with a known pore size distribution (PSD) and in single, homogeneous, slit-shaped carbon pores of different sizes. By comparing the heterogeneous results with those obtained from the ideal adsorbed solution theory and with those obtained in the homogeneous carbon, it was determined that adsorption nonideality and adsorption azeotropes are caused by the coupled effects of differences in the molecular size of the components in a gas mixture and only slight differences in the pore sizes of a heterogeneous adsorbent. For many binary gas mixtures, selectivity was found to be a strong function of pore size. As the width of a homogeneous pore increases slightly, the selectivity for two different sized adsorbates may change from being greater than unity to less than unity. This change in selectivity can be accompanied by the formation of an adsorption azeotrope when this same binary mixture is adsorbed in a heterogeneous adsorbent with a PSD, like in BPL activated carbon. These results also showed that the selectivity exhibited by a heterogeneous adsorbent can be dominated by a small number of pores that are very selective toward one of the components in the gas mixture, leading to adsorption azeotrope formation in extreme cases. PMID:20712330

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

2010-09-01

355

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

356

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...

357

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

358

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

359

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

360

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

361

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

362

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

363

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

364

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

365

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

366

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

367

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

368

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...

369

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

370

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

371

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

372

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

373

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

374

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

375

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

376

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

377

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

378

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

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

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

381

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

382

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

383

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

384

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

385

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

386

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

EPA Science Inventory

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

387

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

388

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

389

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

390

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

391

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

392

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

393

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

394

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

395

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

396

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

397

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

398

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

399

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

400

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

401

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

402

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

403

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

404

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

405

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

406

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

407

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

408

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

409

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

410

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

411

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

412

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

413

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

414

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

415

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

416

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

417

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

418

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

419

Theoretical Consideration on the Characteristics and the Performance Evaluation for a Heat Pump Cycle of Non-azeotropic Refrigerant Mixtures  

NASA Astrophysics Data System (ADS)

The present paper treats a possibility of performance improvement and its evaluation method for a heat pump cycle of non-azeotropic refrigerant mixtures. Calculation is made for R22 + R114 and R22 + R11 mixtures under the conditions that the inlet temperature and flow rates of heat source fluids through a condenser and an evaporator of counter flow type, heat pump thermal output and FK-value (heat transfer area times average overall heat transfer coefficient) are given. It is graphically shown that the coefficient of performance (COP)h, pressures and volumetric flow rates at suction and discharge ports of a compressor depend on the FK-value and on the flow rate of heat source fluid as well as mixture composition. The characteristics of the heat pump cycle thus obtained are markedly different from those, in which the state points of the refrigerant mixture are fixed.

Fujii, Tetsu; Koyama, Shigeru; Miyara, Akio

420

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

421

Modelling of reactive separation processes: reactive absorption and reactive distillation  

Microsoft Academic Search

In the last years chemical process industries have shown permanently increasing interest in the development of reactive separation processes (RSP) combining reaction and separation mechanisms into a single, integrated unit. Such processes bring several important advantages among which are increase of reaction yield and selectivity, overcoming thermodynamic restrictions, e.g. azeotropes, and considerable reduction in energy, water and solvent consumption. Important

C. Noeres; E. Y. Kenig; A. Górak

2003-01-01

422

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

423

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

424

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

425

Modeling of Mass Transfer in Nonideal Multicomponent Mixture with Maxwell-Stefan Approach  

Microsoft Academic Search

The Intalox metal tower packing was used to simulate an industrial relevant extractive distillation column for purifying azeotropic multicomponent mixture. In order to explain the inconsistencies in the modeling of transfer process in nonideal multicomponent distillation column, a method was developed with equilibrium stage models (EQ) and non-equilibrium model (NEQ) incorporated with Maxwell-Stefan diffusion equations in the framework of AspenONE(r)

Yiming SONG; Jinrong SONG; Ming GONG; Bin CAO; Yanhong YANG; Xiaoxun MA

2010-01-01

426

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

427

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

428

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

429

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

430

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

431

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

432

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

433

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

434

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

435

Pervaporation and vapor permeation at the azeotropic point or in the vicinity of the LLE boundary phases of organic\\/aqueous mixtures  

Microsoft Academic Search

Pervaporation and vapor permeation experiments have been performed in order to investigate separately the effect of feed density and concentration on the material transport from the bulk feed to the bulk permeate. Measurements have been carried out for the azeotropic mixtures ethanol\\/water, 1,4-dioxane\\/water and 2-propanol\\/water at 333 and 353 K using a hydrophilic PVA\\/PAN-composite-membrane. In particular the influence of the

M. S. Schehlmann; E. Wiedemann; R. N. Lichtenthaler

1995-01-01

436

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

437

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

438

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

439

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

440

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

441

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

442

Columns in Clay  

ERIC Educational Resources Information Center

|This article describes a clay project for students studying Greece and Rome. It provides a wonderful way to learn slab construction techniques by making small clay column capitols. With this lesson, students learn architectural vocabulary and history, understand the importance of classical architectural forms and their influence on today's…

Leenhouts, Robin

2010-01-01

443

A Column Dispersion Experiment.  

ERIC Educational Resources Information Center

|Crushed glass and a Rhodamine B solution are used in a one-dimensional optically scanned column experiment to study the dispersion phenomenon in porous media. Results indicate that the described model gave satisfactory results and that the dispersion process in this experiment is basically convective. (DC)|

Corapcioglu, M. Y.; Koroglu, F.

1982-01-01

444

Columns in Clay  

ERIC Educational Resources Information Center

This article describes a clay project for students studying Greece and Rome. It provides a wonderful way to learn slab construction techniques by making small clay column capitols. With this lesson, students learn architectural vocabulary and history, understand the importance of classical architectural forms and their influence on today's…

Leenhouts, Robin

2010-01-01

445

Conception et Realisation d'UN Simulateur de Colonne Garnie Fonctionnant Sous Pression Atmospherique et Sous Pression Reduite (Design and Construction of a Packed Column Simulator Operating under Atmospheric and Reduced Pressure).  

National Technical Information Service (NTIS)

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 th...

A. Messaoudene

1989-01-01

446

Comparison of Advanced Distillation Control Methods, Final Technical 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 evaluate configuration selections for single-ended and dual-composition control, as well as to compare conventional and advanced control approaches. In addition, a simulator of a main fractionator was used to compare the control performance of conventional and advanced control. For each case considered, the controllers were tuned by using setpoint changes and tested using feed composition upsets. Proportional Integral (PI) control performance was used to evaluate the configuration selection problem. For single ended control, the energy balance configuration was found to yield the best performance. For dual composition control, nine configurations were considered. It was determined that the use of dynamic simulations is required in order to identify the optimum configuration from among the nine possible choices. The optimum configurations were used to evaluate the relative control performance of conventional PI controllers, MPC (Model Predictive Control), PMBC (Process Model-Based Control), and ANN (Artificial Neural Networks) control. It was determined that MPC works best when one product is much more important than the other, while PI was superior when both products were equally important. PMBC and ANN were not found to offer significant advantages over PI and MPC. MPC was found to outperform conventional PI control for the main fractionator. MPC was applied to three industrial columns: one at Phillips Petroleum and two at Union Carbide. In each case, MPC was found to significantly outperform PI controls. The major advantage of the MPC controller is its ability to effectively handle a complex set of constraints and control objectives.

Dr. James B. Riggs

2000-11-30

447

Limits and Consequences of Nonlocality Distillation  

NASA Astrophysics Data System (ADS)

Only in the last few decades have we realized how to view quantum nonlocal correlations as possible information theoretic resources rather than as apparent paradoxes. Unfortunately, the past perspective in terms of paradoxes still persists in our considerations of nonlocal boxes (NLBs) that offer stronger than quantum nonlocal correlations. We argue that a more pragmatic approach is to consider the physical framework under which such correlations may be realized. Our consideration immediately yields fruit by allowing us to identify limitations of the NLB model and develop the generalized notion of a quantum nonlocal box ( qNLB). We analyze the NLB and qNLB models within the framework of nonlocality distillation protocols. The ability to concentrate the correlations of many identical noisy copies of a nonlocal correlation source is known as nonlocality distillation. The idea is still in its early stages of development and and we pursue it in this thesis. We develop multiple new nonlocality distillation protocols and prove the optimality of non-adaptive distillation protocols for both NLBs and qNLBs. We show that qNLBs offer stronger non-adaptive distillation protocols than NLBs. At the same time, the understanding we develop is that there is no single optimal adaptive protocol for NLB distillation. The choice of which protocol to use depends on the noise parameters for the NLB. Through our investigation of nonlocality distillation protocols we conclude that the qNLB model is 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 limit nonlocal correlations under the framework of qNLBs rather than NLBs. As a first step towards the re-examination of such principles, we provide numerical evidence that the distillability of nonlocal correlations depends on properties that are local. We claim that the differing strength of distillation protocols for NLBs and qNLBs can be interpreted as a separation between classical and quantum predictions at the macroscopic level. This implies that there exist quantum correlations that can be observed in principle, at the macroscopic level or that the principle of macroscopic locality identifies exactly the set of quantum correlations.

Rashid, Jibran

448

Local purity distillation with bounded classical communication  

SciTech Connect

Local pure states are an important resource for quantum computing. The problem of distilling local pure states from mixed ones can be cast in an information theoretic paradigm. The bipartite version of this problem where local purity must be distilled from an arbitrary quantum state shared between two parties, Alice and Bob, is closely related to the problem of separating quantum and classical correlations in the state and in particular, to a measure of classical correlations called the one-way distillable common randomness. In Phys. Rev. A 71, 062303 (2005), the optimal rate of local purity distillation is derived when many copies of a bipartite quantum state are shared between Alice and Bob, and the parties are allowed unlimited use of a unidirectional dephasing channel. In the present paper, we extend this result to the setting in which the use of the channel is bounded. We demonstrate that in the case of a classical-quantum system, the expression for the local purity distilled is efficiently computable and provide examples with their tradeoff curves.

Krovi, Hari; Devetak, Igor [Communication Sciences Institute, University of Southern California, Los Angeles, California 90089 (United States)

2007-07-15

449

4. TYPICAL COLUMN BASE (COLUMN #1 ON PHOTO ELEVATION PLAN) ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. TYPICAL COLUMN BASE (COLUMN #1 ON PHOTO ELEVATION PLAN) FACING SOUTH. - U.S. Naval Base, Pearl Harbor, Signal Tower, Corner of Seventh Street & Avenue D east of Drydock No. 1, Pearl City, Honolulu County, HI

450

11. TIMBER COLUMN AND CAST IRON COLUMN CAP IN FIFTH ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

11. TIMBER COLUMN AND CAST IRON COLUMN CAP IN FIFTH FLOOR WAREHOUSE SPACE. VIEW TO SOUTHWEST. - Commercial & Industrial Buildings, Becker-Hazelton Company Warehouse, 280 Iowa Street, Dubuque, Dubuque County, IA

451

43. Details of Columns / Details of Column Splice / ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

43. Details of Columns / Details of Column Splice / Detail of Concrete Ceiling at Walls on 2nd Floor (drawing S9) - Whittier State School, Hospital & Receiving Building, 11850 East Whittier Boulevard, Whittier, Los Angeles County, CA

452

Superadditivity of distillable entanglement from quantum teleportation  

SciTech Connect

We show that the phenomenon of superadditivity of distillable entanglement observed in multipartite quantum systems results from the consideration of states created during the execution of the standard end-to-end quantum teleportation protocol [and a few additional local operations and classical communication (LOCC) steps] on a linear chain of singlets. Some of these intermediate states are tensor products of bound entangled (BE) states, and hence, by construction possess distillable entanglement, which can be unlocked by simply completing the rest of the LOCC operations required by the underlying teleportation protocol. We use this systematic approach to construct both new and known examples of superactivation of bound entanglement, and examples of activation of BE states using other BE states. A surprising outcome is the construction of noiseless quantum relay channels with no distillable entanglement between any two parties, except for that between the two end nodes.

Bandyopadhyay, Somshubhro; Roychowdhury, Vwani [Centre for Quantum Information and Quantum Control and Department of Chemistry, University of Toronto, Toronto, Ontario, M5S 3H6 (Canada); Electrical Engineering Department, UCLA, Los Angeles, California 90095 (United States)

2005-12-15

453

Entanglement distillation protocols and number theory  

SciTech Connect

We show that the analysis of entanglement distillation protocols for qudits of arbitrary dimension D benefits from applying basic concepts from number theory, since the set Z{sub D}{sup n} associated with Bell diagonal states is a module rather than a vector space. We find that a partition of Z{sub D}{sup n} into divisor classes characterizes the invariant properties of mixed Bell diagonal states under local permutations. We construct a very general class of recursion protocols by means of unitary operations implementing these local permutations. We study these distillation protocols depending on whether we use twirling operations in the intermediate steps or not, and we study them both analytically and numerically with Monte Carlo methods. In the absence of twirling operations, we construct extensions of the quantum privacy algorithms valid for secure communications with qudits of any dimension D. When D is a prime number, we show that distillation protocols are optimal both qualitatively and quantitatively.

Bombin, H.; Martin-Delgado, M.A. [Departamento de Fisica Teorica I, Universidad Complutense, 28040 Madrid (Spain)

2005-09-15

454

Distillation of local purity from quantum states  

SciTech Connect

Recently Horodecki et al. [Phys. Rev. Lett. 90, 100402 (2003)] introduced an important quantum information processing paradigm, in which two parties sharing many copies of the same bipartite quantum state distill local pure states by means of local unitary operations assisted by a one-way (two-way) completely dephasing channel. Local pure states are a valuable resource from a thermodynamical point of view, since they allow thermal energy to be converted into work by local quantum heat engines. We give a simple information-theoretical characterization of the one-way distillable local purity, which turns out to be closely related to a previously known operational measure of classical correlations, the one-way distillable common randomness.

Devetak, I. [Electrical Engineering Department, University of Southern California, Los Angeles, California 90089 (United States)

2005-06-15

455

Nonequilibrium Positive Column II.  

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. In the present paper, the nonlocal moment method is compared with two of the most often used local moment methods: (i) local moment method with Maxwell EEDF; (ii) local moment method with 0D EEDF. The form of the Boltzmann equation for electrons in a positive column discharge suggests that each gas has a characteristic curve of positive column E/N versus NR (E is axial electric field, N is gas density, and R is tube radius). This characteristic curve affords a systematic way of comparing various methods because its course depends on the form of the EEDF used to calculate transport coefficients and inelastic collision rates, on whether or not it is assumed that the electrons are in equilibrium with the axial field, on whether or not ion inertia is taken into account, etc. Using an argon-like gas for illustration, it is shown that the characteristic curve based on equilibrium with 0D EEDF is a poor approximation to that based on nonequilibrium for NR less than 1× 10^17 cm-2 (PR<3 Torr-cm), while that based on equilibrium with Maxwell EEDF is an extremely poor approximation at any value of NR. [1]D. Uhrlandt and R. Winkler, J. Phys. D 29, 115 (1996). [2]J. H. Ingold, Phys. Rev. E 56, 5932 (1997).

Ingold, John H.

1998-10-01

456

[Determination of tetrodotoxin in fermentation broth of distiller's yeast by ion chromatography].  

PubMed

A method was developed for the quantitative analysis of tetrodotoxin (TTX) in fermentation broth of distiller's yeast by ion chromatography. After extraction with acetonitrile solution (containing 0.1% phosphoric acid) and purification with an ion-exchange column, the tetrodotoxin was separated by ion chromatography and detected by a ultraviolet-visible (UV-VIS) absorbance detector. The experimental results showed that the tetrodotoxin had a good linearity (r2 = 0.997) in the range of 10 - 100 mg/L and the detection limit (3 of signal-to-noise ratio) was 1.0 mg/L. The average recoveries were between 90% - 103% with a relative standard deviation lower than 4.9%. The analysis of real samples verified the reliability of this method and demonstrated that the ion chromatography can be used for the quantification detection of the tetrodotoxin. The degradation experiment results suggested that distiller's yeast had a remarkable effect on the tetrodotoxin degradation. PMID:21598524

Shu, Jing; Li, Bailin; Ou, Jie

2011-02-01

457

Fiber separation from distillers dried grains with solubles using a larger elutriation apparatus and use of fiber as a feedstock for corn fiber gum production  

Technology Transfer Automated Retrieval System (TEKTRAN)

In an earlier study, the combination of sieving and elutriation (air flow) was found to be effective in separating fiber from distillers dried grains with solubles (DDGS); the elutriation column diameter used was 63 mm. Larger quantities of fractions were needed for carrying out studies on producti...

458

3 HPLC columns and packings  

Microsoft Academic Search

In this chapter on HPLC columns, we are discussing both the surface chemistry of a packing as well as column design and performance. In the section that covers column chemistry, we cover modern options of base materials as well as the commonly used approaches towards the surface chemistry of a packing. Specific subsections are dedicated to the selectivity of reversed-phase

Uwe D. Neue; Bonnie A. Alden; Edward R. Grover; Eric S. Grumbach; Pamela C. Iraneta; Alberto Méndez

2007-01-01

459

4 HPLC columns for pharmaceutical analysis  

Microsoft Academic Search

This chapter deals with the properties of high-pressure liquid chromatography columns. It is divided into two sections: column physics and column chemistry. In the section on column physics, we discuss the properties that influence column performance, such as particle size, column length and column diameter, together with the effect of instrumentation on the quality of a separation. In the section

Uwe D. Neue; Bonnie A. Alden; Pamela C. Iraneta; Alberto Méndez; Eric S. Grumbach; Kimvan Tran; Diane M. Diehl

2005-01-01

460

Model reduction and optimization of reactive batch distillation based on the adaptive neuro-fuzzy inference system and differential evolution  

Microsoft Academic Search

This paper considers the application of the adaptive neuro-fuzzy inference system (ANFIS) instead of the highly nonlinear\\u000a model of a reactive batch distillation column for optimization. The architecture has been developed for fuzzy modeling that\\u000a learns information from a data set, in order to compute the membership function and rule base in accordance with the given\\u000a input–output data. In this

S. M. Khazraee; A. H. Jahanmiri; S. A. Ghorayshi

2011-01-01

461

Catalytic hydroprocessing of SRC-II heavy distillate fractions. 1. Preparation of the fractions by liquid chromatography  

Microsoft Academic Search

Liquid chromatography, with columns containing cation-exchange resin and clay-supported FeâCl \\/SUB g\\/, was used on a preparative scale to separate 10 100-g batches of a coal-derived liquid (SRC-II) heavy distillate into nine fractions, each consisting of chemically similar compounds. The fractions are strong, weak, and very weak bases; strong, weak, and very weak acids; neutral oils; neutral resins; and asphaltenes.

Leonidas Petrakis; Raffaele G. Ruberto; Donald C. Young; Bruce C. Gates

1983-01-01

462

DYNAMICS AND CONTROL DURING START-UP OF ENERGY INTEGRATED DISTILLATION COLUMN  

Microsoft Academic Search

To advocate the usage of process integration in industrial practice, it i s important t o b e a ble to guarantee not only robust control during near steady state operation, but also to provide procedures for generating fast and reliable start-up sequences. This contribution concentrates on d escribing a systematic procedure for development of plant start-up sequences. The basis

Mario Richard Eden; Arne Koggersbøl; Louis Hallager; Sten Bay

463

Using Artificial Neural networks for the modelling of a distillation column  

Microsoft Academic Search

The main aim of this paper is to establish a reliable model both for the steady-state and unsteady-state regime s of a nonlinear process. The use of this model should reflect the true behavior of the process under its normal operating conditions and allow distinguishing a normal mode from an abnormal one. In order to obtain this reliable model for

Yahya Chetouani

2007-01-01

464

FUNCTION AND PERFORMANCE OF A PRE?REACTOR TO A REACTIVE DISTILLATION COLUMN FOR BIODIESEL PRODUCTION  

Microsoft Academic Search

This article describes an in?depth follow?up to previous studies showing that an oil?methanol mixer prior to an RD reactor played an important role in enhancing the overall performance of the RD reactor system. An in?line static mixer was used for the purpose of providing initial mixing of the reactants, heating the mixture up to the desired operating temperature, and carrying

B. B. He; A. P. Singh; J. C. Thompson

465

Reparametrized ARX models for predictive control of staged and packed bed distillation columns  

Microsoft Academic Search

This work is aimed at the development of reparametrized ARX type models for high dimensional and distributed parameter systems. To keep data length small while identifying a model with ARX structure, the feasibility of reparametrizing ARX models using the fractional order differential operators and orthonormal basis filters is explored. The identified noise model is further used for developing a novel

M. Muddu; Anuj Narang; Sachin C. Patwardhan

2010-01-01

466

21 CFR 184.1848 - Starter distillate.  

Code of Federal Regulations, 2013 CFR

...distillate of the culture of any or all of the following species of bacteria grown on a medium consisting of skim milk usually fortified...dextranicum. The ingredient contains more than 98 percent water, and the remainder is a mixture of butterlike flavor...

2013-04-01

467

Membrane-distillation desalination: Status and potential  

Microsoft Academic Search

This paper presents an assessment of membrane distillation (MD) based on the available state of the art and on ourpreliminary analysis. The process has many desirable properties such as low energy consumption, ability to use low temperature heat, compactness, and perceivably more immunity to fouling than other membrane processes. Within the tested range, the operating parameters of conventional MD configurations

A. M. Alklaibi; Noam Lior

2005-01-01

468

Desalination by Membrane Distillation: A Parametric Study  

Microsoft Academic Search

Membrane distillation was investigated as a possible technique for desalination. An air-gap module with built-in Condensing surface was used for conducting experiments on polyvinylidene fluoride flat membrane sheets. The feed stream tested was artificial seawater. The quality of the permeate, quantified by conductivity measurements, and the permeate flux were monitored as the feed temperature, feed flow rate, cooling temperature, and

Fawzi A. Banat; Jana Simandl

1998-01-01

469

Seawater desalination by direct contact membrane distillation  

Microsoft Academic Search

Membrane fouling still posts as one of the major obstacles in membrane distillation (MD). This is why the MD approach still cannot successfully compete with other conventional seawater desalination methods. In this study, both the NaCl solution and real seawater are used as the feed of MD processes to investigate the differences in permeate flux, product water quality and membrane

S. T. Hsu; K. T. Cheng; J. S. Chiou

2002-01-01

470

EXTRACTIVE DISTILLATION WITH AQUEOUS SOLUTIONS OF HYDROTROPES  

Microsoft Academic Search

The effect of hydrotropes on vapor-liquid equilibrium of a mixture provides a potential technique of extractive distillation for systems which are difficult or impossible to separate by normal rectification. Various hydrotropes, such as sodium toluate, sodium toluence sulfonate, sodium cymcnc sulfonate, sodium mesitylene sulfonate and sodium salicylate, in aqueous solutions have been tested for the separation of close-boiling point mixtures,

MAMTA AGARWAL; V. G. GAIKAR

1992-01-01

471

Industry and Trade Summary: Distilled Spirits.  

National Technical Information Service (NTIS)

The U.S. distilled spirits industry is characterized by a three-tier structure of (1) producers/suppliers, (2) wholesale distributors, and (3) retailers. Each tier must operate independently from the other two tiers as mandated by Federal and State laws. ...

2000-01-01

472

Distillation Calculations with a Programmable Calculator.  

ERIC Educational Resources Information Center

|Describes a three-step approach for teaching multicomponent distillation to undergraduates, emphasizing patterns of distribution as an aid to understanding the separation processes. Indicates that the second step can be carried out by programmable calculators. (A more complete set of programs for additional calculations is available from the…

Walker, Charles A.; Halpern, Bret L.

1983-01-01

473

Physiochemical Characterization of Soybean Oil Deodorizer Distillate  

Microsoft Academic Search

Increased use of industrial waste and byproducts fits the need of industry to comply with environmental rules. The substitution of natural products for artificial ingredients has gained worldwide attention in the food, pharmaceutical and other industries. These facts justify the study on the utilization of Soybean Oil Deodorizer Distillate (SODD) as tocopherol supplements. Tocopherol, which is physiologically active as vitamin

Cibelem Iribarrem BENITES; Soely Maria

474

Distillation plant development and cost update  

Microsoft Academic Search

Recent developments in desalination technology have resulted in significant savings in cost compared with earlier plants. Both distillation and reverse osmosis processes are now viable means of water production from a seawater source in the developing countries of the MENA area as well as in the more traditional oil-producing Gulf States. Three processes are commercially available for large size plants

Neil M. Wade

2001-01-01

475

Oxidative desulfurization of lube oil distillates  

Microsoft Academic Search

The problem of manufacturing low-sulfur oils has become much more acute with the increase in refining of medium-sulfur crudes. The difficulties in obtaining lube oils with a low sulfur content are due to the restricted selection of feedstock, changes in its composition, and especially the lack of hydrotreating in the refinery. The method of selective treatment of lube oil distillates

V. R. Nigmatullin; R. R. Mukhametova; I. R. Nigmatullin

2008-01-01

476

The fermentation process integrated with membrane distillation  

Microsoft Academic Search

Ethanol production in tubular bioreactor integrated with the membrane distillation (MD) system has been investigated. The fermentation of sugar with Saccharomyces cerevisiae proceeds with the formation of by-products, which tends to inhibit the yeast productivity. The removal of by-products from the fermenting broth by MD process increased the efficiency and the rate of sugar conversion to ethanol. The fermentation process

Marek Gryta

2001-01-01

477

MODELLING OF REACTIVE DISTILLATION - PROPYLENE OXIDE PRODUCTION  

Microsoft Academic Search

Selectivity and equilibrium of chemical reactions can be significantly influenced by the distillation of one or more products from the reaction mixture. Simultaneous reaction and separation of the desired product is very important in the case of consecutive reactions. Simulation of the reactor for propylene oxide (POX) synthesis from propylenechlorohydrine (PCH) and calcium hydroxide is presented in the paper. The

M. Kotora; Z. Švandová

2005-01-01

478

Holoprosencephaly: A mythologic and teratologic distillate.  

PubMed

This review of holoprosencephaly provides a mythologic and teratologic distillate of the subject under the following headings: Babylonian tablets; Greek mythology; pictures from the 16th through the 20th Centuries; 19th Century teratology; history of more modern concepts and their terminologies; and ocean-going ships named "Cyclops." PMID:20082455

Cohen, M Michael

2010-02-15

479

PPMCSA Presentation on Winter Distillate Outlook  

NSDL National Science Digital Library

This presentation on the Winter Distillate Outlook was created for the PPMCSA Meeting and Trade Show of this year. It gives basic information and forecasts on the prices of a variety of energy sources through a collection of slides and accompanying notes.

480

Removal of water haze from distillate fuel  

SciTech Connect

A method is described for de-hazing distillate fuel which comprises adding to the fuel an organosiloxane having at least one quaternary ammonium substituted siloxane unit having the general formula R/sub a/ZSiO/sub (3-a)/2/ in which a has the value 1 or 2, each R is selected from the group consisting of substituted and unsubstituted hydrocarbon groups having up to 10 carbon atoms, provided that one R may be a hydroxyl group when a has the value 2, Z represents a quaternary ammonum group having the formula R'N/sup +/(R/sup 2/)/sub 3/X/sup -/ linked to the silicon atom of the siloxane unit, in which R' represents a divalent hydrocarbon group linking the silicon and nitrogen atoms, each R/sup 2/ represents an alkyl group having up to 20 carbon atoms and X/sup -/ represents a halogen ion, the distillate fuel containing up to about 0.1 percent by weight of water dispersed therein. The patent also describes a mixture consisting essentially of a distillate fuel and up to about 0.1 percent by weight of water based on the weight of the distillate fuel; with a de-hazing amount of an organosiloxane having at least one quaternary ammonium substituted siloxane unit.

Easton, T.; Thomas, B.

1989-04-04

481

Entanglement distillation protocols and number theory  

Microsoft Academic Search

We show that the analysis of entanglement distillation protocols for qudits of arbitrary dimension D benefits from applying basic concepts from number theory, since the set ZDn associated with Bell diagonal states is a module rather than a vector space. We find that a partition of ZDn into divisor classes characterizes the invariant properties of mixed Bell diagonal states under

H. Bombin; M. A. Martin-Delgado

2005-01-01

482

Superadditivity of distillable entanglement from quantum teleportation  

Microsoft Academic Search

We show that the phenomenon of superadditivity of distillable entanglement observed in multipartite quantum systems results from the consideration of states created during the execution of the standard end-to-end quantum teleportation protocol [and a few additional local operations and classical communication (LOCC) steps] on a linear chain of singlets. Some of these intermediate states are tensor products of bound entangled

Vwani Roychowdhury; Somshubhro Bandyopadhyay

2005-01-01

483

Zirconium and hafnium tetrachloride separation by extractive distillation with molten zinc chloride calcium and/or magnesium chloride solvent  

SciTech Connect

This patent describes an extractive distillation method for separating hafnim tetrachloride from zirconium tetrachloride of the type wherein a mixture of zirconium and hafnium tetrachlorides is introduced into an extractive distillation column, which distillation column has a reflux reboiler connected at the bottom and a reflux absorber connected at the top and wherein a molten salt solvent is circulated into the reflux absorber and through the column to provide a liquid phase. The molten salt solvent contains zirconium tetrachloride and 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 absorber and hafnium tetrachloride enriched vapor is taken as product from the reflux absorber. The improvement comprises: the molten salt solvent having a composition of at least 80 weight percent zinc chloride and at least 5 percent of a viscosity reducer, the viscosity reducer being chosen from the group consisting of magnesium chloride; and calcium chloride, and mixtures thereof.

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

1988-06-07

484

Kinetics and effectiveness of catalyst for synthesis of methyl tert-butyl ether in catalytic distillation  

SciTech Connect

The macrokinetics and intrinsic kinetics were measured for synthesis of methyl tert-butyl ether (MTBE) within the catalyst bed packed in a special way in an industrialized catalytic distillation column. The corresponding kinetic equations for forward and backward reactions were obtained. The variation of total effectiveness factor of the catalyst considering the diffusion in the catalyst pocket and within a granule of catalyst with reaction temperature and diameter of the pocket was calculated from the results measured. It was indicated that the effect of the catalyst packed in this way could not be revealed under the present operation condition.

Xu, X.; Zheng, Y.; Zheng, G. [Tianjin Univ. (China). Dept. of Chemical Engineering

1995-07-01

485

27 CFR 19.651 - Liability for distilled spirits tax.  

Code of Federal Regulations, 2013 CFR

27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Liability for distilled spirits tax...651 Alcohol, Tobacco Products and Firearms ALCOHOL AND...by the Vaporizing Process Liability for Distilled Spirits Tax...

2013-04-01

486

Steam distillation effect and oil quality change during steam injection.  

National Technical Information Service (NTIS)

Steam distillation is an important mechanism which reduces residual oil saturation during steam injection. It may be the main recovery mechanism in steamflooding of light oil reservoirs. As light components are distilled the residual (initial) oil, the re...

K. T. Lim H. J. Ramey W. E. Brigham

1992-01-01

487

DISTILLATION OF LIGHT WATER FROM HEAVY WATER MODERATOR  

Microsoft Academic Search

A description is given of the equipment and method of operation of a ; distillation system to remove light water from heavy water moderator. The basic ; principles of the theory of distillation are reviewed. ( auth);

Bertsche

1958-01-01

488

Combination process for the conversion of a distillate hydrocarbon to maximize middle distillate production  

SciTech Connect

A process is described for the conversion of an aromatic-rich, distillable gas oil charge stock which is essentially free from asphaltenic hydrocarbons. This process possesses an aromatic hydrocarbon concentration greater than about 20 volume percent to selectively produce large quantities of high quality middle distillate while minimizing hydrogen consumption. The steps for the process are: reacting the charge stock with hydrogen, in a catalytic hydrocracking reaction zone, at hydrocracking conditions; separating the resulting hydrocracking reaction zone effluent to provide a middle distillate product stream and a paraffin-rich hydrocarbonaceous stream; recovering the middle distillate product stream; reacting the paraffin-rich hydrocarbonaceous stream in a non-catalytic thermal reaction zone at mild thermal cracking conditions including an elevated temperature; separating the non-catalytic thermal reaction zone effluent to provide a fraction boiling and a hydro-carbonaceous stream boiling; and reacting at least a portion of the hydrocarbonaceous stream boiling.

Humbach, M.J.; Hale, J.G.

1987-04-28

489

Nonequilibrium positive column  

SciTech Connect

The dc positive column is modeled with a system of balance equations based on moments of the radially dependent Boltzmann equation taken after the two-term Legendre expansion of the electron energy distribution function is made. The importance of the electron energy balance equation, which is frequently ignored in positive column analysis, is emphasized. A key assumption is that electron transport coefficients and collision frequencies in the nonequilibrium regime have the same relation to the average energy as in the equilibrium regime, according to a zero-dimensional Boltzmann solution for a particular value of average energy. Because of this assumption, the model makes a smooth transition to the traditional equilibrium model with radially constant average energy at sufficiently high pressure. Model results in the nonequilibrium regime agree closely with published results of a numerical solution of the one-dimensional Boltzmann equation, including results for radial heat flow in the electron gas with radially varying average energy. It is shown that three separate processes account for radial heat flow: convection, conduction, and diffusion. In the example chosen for illustration of the method, the convection component is small, while the conduction and diffusion components are large and opposite in direction, nearly canceling each other. {copyright} {ital 1997} {ital The American Physical Society}

Ingold, J.H. [One Bratenahl Place, Suite 610, Cleveland, Ohio 44108 (United States)

1997-11-01

490

Interpolation of recurrence and hashing entanglement distillation protocols  

SciTech Connect

We construct interesting entanglement distillation protocols by interpolating between the recurrence and hashing protocols. This leads to asymptotic two-way distillation protocols, resulting in an improvement of the distillation rate for all mixed Bell diagonal entangled states, even for the ones with very high fidelity. We also present a method for how entanglement-assisted distillation protocol can be converted into nonentanglement-assisted protocols with the same yield.

Vollbrecht, Karl Gerd H.; Verstraete, Frank [Max-Planck-Institut fuer Quantenoptik, Hans-Kopfermann-Str. 1, D-85748 Garching (Germany)

2005-06-15

491

The effect of perphenazine on epinephrine-induced cardiac arrhythmias in dogs: I, anaesthesia with fluothane, and fluothane-ether azeotrope  

Microsoft Academic Search

Summary  Thirty acute standard experiments were carried out on twenty dogs during anaesthesia with 0.5 per cent Fluothane and 1 per\\u000a cent Fluothane-ether azeotrope with N2O:O2 (5:2) to determine whether perphenazine would prevent serious or fatal ventricular arrhythmias, provoked by a lethal dose\\u000a of ?epinephrine, after approximately 25 mm. of anaesthesia Pulmonary ventilation was controlled mechanically in a non-rebreathing\\u000a svstem during

Allen B. Dobkin; Noel Purkin

1959-01-01

492

Steam distillation effect and oil quality change during steam injection  

Microsoft Academic Search

Steam distillation is an important mechanism which reduces residual oil saturation during steam injection. It may be the main recovery mechanism in steamflooding of light oil reservoirs. As light components are distilled the residual (initial) oil, the residuum becomes heavier. Mixing the distilled components with the initial oil results in a lighter produced oil. A general method has been developed

K. T. Lim; H. J. Jr. Ramey; W. E. Brigham

1992-01-01

493

Vapor compression distiller and membrane technology for water revitalization  

Microsoft Academic Search

Water revitalization for a space station can consist of membrane filtration processes and a distillation process. Water recycling equipment using membrane filtration processes was manufactured for ground testing. It was assembled using commercially available components. Two systems for the distillation are studied; one is an absorption type thermopervaporation cell and the other is a vapor compression distiller. Absorption type thermopervaporation

A. Ashida; K. Mitani; K. Ebara; H. Kurokawa; I. Sawada; H. Kashiwagi; T. Tsuji; S. Hayashi; K. Otsubo; K. Nitta

1987-01-01

494

27 CFR 1.82 - Acquiring or receiving distilled spirits in bulk for redistillation, processing, rectification...  

Code of Federal Regulations, 2010 CFR

... Acquiring or receiving distilled spirits in bulk for redistillation, processing, rectification...NONINDUSTRIAL USE OF DISTILLED SPIRITS AND WINE, BULK SALES AND BOTTLING OF DISTILLED SPIRITS Bulk Sales and Bottling of Distilled Spirits...

2010-04-01

495

27 CFR 1.82 - Acquiring or receiving distilled spirits in bulk for redistillation, processing, rectification...  

Code of Federal Regulations, 2010 CFR

... Acquiring or receiving distilled spirits in bulk for redistillation, processing, rectification...NONINDUSTRIAL USE OF DISTILLED SPIRITS AND WINE, BULK SALES AND BOTTLING OF DISTILLED SPIRITS Bulk Sales and Bottling of Distilled Spirits...

2009-04-01

496

27 CFR 19.739 - Authorized transfers to or from distilled spirits plants.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Authorized transfers to or from distilled spirits plants...Distilled Spirits for Fuel Use Transfer of Spirits to and from Distilled...Plants § 19.739 Authorized transfers to or from distilled spirits...

2013-04-01

497

SPIRAL CONTACTOR FOR SOLVENT EXTRACTION COLUMN  

DOEpatents

The patented extraction apparatus includes a column, perforated plates extending across the column, liquid pulse means connected to the column, and an imperforate spiral ribbon along the length of the column.

Cooley, C.R.

1961-06-13

498

Stability of Column-Supported Embankments.  

National Technical Information Service (NTIS)

Column-supported embankments have a great potential for application in the coastal regions of Virginia, where highway embankments are often constructed on soft ground. The columns can be driven piles, vibro-concrete columns, deepmixing- method columns, st...

G. M. Filz M. P. Navin

2006-01-01

499

Leaching potential of phenylurea herbicides in a calcareous soil: comparison of column elution and batch studies.  

PubMed

The transfer of eleven phenylurea herbicides through soil columns was investigated in laboratory conditions in order to determine leaching properties in a calcareous soil. Elution curves with distilled water were plotted after herbicide application on the soil column. Phenylurea retention by the soil indicating interactions with soil can be classified as follows: fenuron < fluometron ? isoproturon = monuron < metoxuron < monolinuron < metobromuron < chlorotoluron < linuron = diuron < chlorbromuron. The number and nature of halogen atoms on the phenyl ring had an important influence on leaching. Retention was higher for molecules with higher number of halogen, and it was also higher for bromine than chlorine. Column elution experiments were compared to batch experiments from which the distribution coefficients K (d) were determined. According to Kendall correlation coefficients, parameter m/m (0max) from column experiments was relatively well linked to K (d). In case of phenylurea, a linear relationship between K (d) and m/m (0max) was established. PMID:23097070

Langeron, Julie; Sayen, Stéphanie; Couderchet, Michel; Guillon, Emmanuel

2012-10-23

500

Solar desalination by freezing and distillation  

NASA Astrophysics Data System (ADS)

It is noted that among seawater desalination processes the absorption-freeze vapor compression processes based on the thermal heat pump, although untested commercially and still in the development stage, appears technically and economically an attractive application of low-grade (exergy) solar heat. The distillation processes proposed here may be conveniently powered by low-grade solar heat (from flat plate solar collectors). It is expected that the scaling problem will be insignificant in comparison with that encountered in the conventional multistage flash process. The novel feature here is the use of enlarged capacity for heat exchange between distillate and brine via latent heat of solid-liquid phase change of a suitable hydrophobic intermediate heat transfer material.

Kvajic, G.