Binary Vapor-Liquid Equilibrium for C3 Hydrocarbons* By

Total Page:16

File Type:pdf, Size:1020Kb

Binary Vapor-Liquid Equilibrium for C3 Hydrocarbons* By Binary Vapor-Liquid Equilibrium for C3 Hydrocarbons* by ToshikatsuHakuta**, KunioNagahama**, and MitsuhoHirata** Summary: High-purity propylenefeedstock is required for manufacture of polypropylene. Accurate vapor-liquid equilibrium data of C3 hydrocarbonsare essentialfor the determination of fractionation requirementsto obtain high-purity propylenefrom a C3 hydrocarbonmixture. The apparatus used in this investigationwas a modificationof theforced-circulation type. It has been stated by Ruhemann1)that this type of apparatus is the most accurate and reliable of all low temperature method. Binary vapor-liquid equilibrium relationships for the propylenepropane, propylene- propadiene(allene) and propane-propadienesystems were determinedat isothermal conditionsof 0℃ and 20.1℃. In these three binary mixtures, the propanepropadiene systemforms a minimum boiling azeotropic mixture. Azeotropic conditionswere determinedusing a smoothingmethod proposed by Suda2)which was basedon a simplerelation in vapor-liquidequilibrium ratio of the constituents. 1 Introduction a minimum purity of 99%. The equilibrium data for the propylene-pro- 3 Experimental Apparatus and Experimen- pane system have been reported by Reamer and tal Method Sage3), by Hanson et al4), by Mann, Pardee and 3.1 Apparatus Smyth5) and by Hirata, Hakuta and Onoda8). But The experimental apparatus used in this in- data for propylene-propadiene and propane-pro- vestigation is illustrated in Figure 1. This ap- padiene systems have not been published. Hill et al.7) suggested that greater deviation from ideality paratus for measuring the vapor-liquid equilibrium might be expected for the system such as the is one of the types of forced circulation of the vapor phase. This is entirely made of stainless steel propane-propadiene, with greater differences in the degree of saturation of molecular structure. designed for operating conditions; temperatures as low as -200℃ and pressures up to 100 atm.. It is reported in "Azeotropic Data-II"8) that the The equilibrium cell has a capacity of 150ml. propane-propadiene system formed a minimum boiling azeotropic mixture, but vapor-liquid equi- with glass windows for inspection from outside. librium data are not unpublished. So the authors Both the vapor and liquid phase sampling cells investigated equilibrium relationships for propyl- have a capacity of 10ml., detailed descriptions of ene-propane, propylene-propadiene and propane- which were made previously9). The sampling propadiene systems, and determined azeotropic vessel, in which the liquid sample is allowed to points of the propane-propadiene system at 0℃ vaporize, has a capacity of about 100ml.. and 20.1℃. The circulation of the vapor phase is carried out by means of a magnetic pump provided with two 2 Materials check valves. The magnetic pump is shown in The propylene and propane samples were fur- Figure 2. The rate of circulation can be adjusted nished by Takachiho Chemical Industry Co.. at will between 0ml/min and 300ml/min. The propylene sample was specified to contain The measurement of temperature in this inves- 99.32% propylene, 0.05% ethane, 0.15% propane tigation was carried out by a mercury thermometer. and 0.49% air, and the propane sample was The pressure was read with a differential pressure specified to contain 99.85% propane, 0.05% ethane gauge and a dead weight pressure tester. and 0.10% air. The propadiene (allene) sample was furnished by The Matheson Co. Inc. and had 3.2 Experimental Method First, V in Figure 1, is connected to a vacuum * Received November 18, 1968. ** Faculty of Engineering, Tokyo Metropolitan Univer- pump for evacuation the system completely. A sity (2-1-1, Fukazawa, Setagaya-ku, Tokyo, Japan). high-boiling component is introduced into the Bulletin of The Japan Petroleum Institute Hakuta, Nagahama and Hirata: Binary Vapor-Liquid Equilibrium for C3 Hydrocarbons 11 Fig. 1 Schematic Diagram of V-L Equilibrium Apparatus Fig. 2 Magnetic Piston Pump Fig. 3 Pressure-Composition Diagram of Propylene- Propane System system from a sample cylinder. The equlibrium cell is maintained at a desired temperature.The 0℃ run was taken with ice of 0.01kg/cm2 and the valves of the vapor phase and water in cooling bath and the 20.1℃ run was sampling cell are closed in order to sample the done in the constant temperature bath which was vapor-phase. As vapor phase is circulated through controlled by means of temperature controller. the by-pass in vapor phase sampling cell at this After the temperature desired was obtained, the time, the equilibrium condition is not broken. magnetic pump is operated to circulate the vapor Immediately thereafter, the liquid sample is col- phase, and high and/or low boiling components lected in the evacuated liquid phase sampling are fed into the system. When the liquid surface vessel and the sampling cell. in equilibrium cell was adjusted and pressure was The sample is subjected to gas chromatographic reached to a desired level, the feed valve is closed. analysis by valve operation. When a steady state was established for about The analysis was carried out by Yanagimoto half an hour, the pressure is read to an accuracy GCG-3DH Gas Chromatograph equipped with 4 Volume 11-May 1969 12 Hakuta, Nagahama and Hirata: Binary Table 1 Vapor-Liquid Equilibrium Original Data System: Propylene (1)-Propane (2) at 0℃ Table 2 Vapor-Liquid Equilibrium Original Data System: Propylene (1)-Propadiene (2) at 0℃ Bulletin of The Japan Petroleum Institute Vapor-Liquid Equilibrium for C3 Hydrocarbons 13 Table 3 Vapor-Liquid Equilibrium Original Data System: Propane (1)-Propadienc (2) at 0℃ Fig. 4 Pressure-Composition Diagram of Propylene- Propadiene System m. Activated Aluminum/Squalane column. Hy- drogen was used as a carrier gas and the flow rate was 80ml/min. The column temperature was Fig. 5 Pressure-Composition Diagram of Propane- about 60℃ and the filament current was 200mA. Propadiene System Volume 11-May 1969 14 Hakuta, Nagahama and Hirata: Binary Table 4 Azeotropic Data for Propane-Propadiene System Fig. 6 α-χ1 Diagram of Propylene -Propane System Fig. 9 γ1, γ2-χ1 Diagram of Propylene -Propane Sys- tem at 20.1℃ Fig. 7 α-χ1 Diagram of Propylene-ProPadiene System Fig. 10 γ1, γ2-χ1 Diagram of Propylene -Propadiene System at 0℃ Fig. 8 α-χ1 Diagram of Propane-Propadiene System 4 Experimental Results and Discussion Experimental results of vapor-liquid equili- brium measurements for the propylene-propane, Fig. 11 γ1, γ2-χ1 Diagram of Propane-Propadiene Sys- propylene-propadiene and propane-propadiene tem at 20.1℃ Bulletin of The Japan Petroleum Institute Vapor-Liquid Equilibrium for C3 Hydrocarbons 15 system were tabulated in Table 1, Table 2 and volatility with temperatures was small in the Table 3, respectively. In these tables, Ki, a propylene-propane system, but was considerably and γi were calculated in the following equations. large in the propylene-propadiene and propane- yi propadiene systems. The propane-propadiene Ki (1) χi system formed a minimum boiling azeotropic mix- yi (1-χi) ture and the azeotropic points were determined. αij (2) χi (1-yi) πyi Acknowledgement γi (3) Piχi The author's thanks are due to Y. Misaki, N. Figure 3, 4 and 5 show the pressure-composition Tanaka and T. Mori who helped us in the experi- diagram for the above systems. Figure 6, 7 and 8 mental work of this investigation, and also to show the relative volatility (α)-liquid composition Chisso Co., Ltd. for the supply of high-purity C3 diagrams. As shown in Figure 6, 7 and 8, relative hydrocarbons used in this work. volatility of the propylene-propane system is not affeced by the variation of temperature. On Nomenclature the other hand, the relative volatility for the K Vapor-liquid equilibrium ratio P Pressure, kg/cm2. abs. propylene-propadiene and propane-propadiene P゜ Vapor pressure of pure component, kg/cm2・abs. systems is considerably affected. T Temperature,℃ In these systems the propane-propadiene system x Mole fraction in liquid phase formed a minimum boiling azeotropic mixture. y Mole fraction in vapor phase α Relative volatility Azeotropic points at 0℃ and 20.1℃. are shown γ Activity coefficient in Table 4. Figure 9, 10 and 11 show the activity π System pressure, kg/cm2・abs. Subscripts coefficients-liquid composition diagrams for each Subscripts system. These systems have a crosspoint in ac- tivity coefficients, but the propylene-propadiene 1 Low boiling component 2 High boiling component system at 20.1℃ has not. In this system the i i component activity coefficients for propylene (γ1) are scattered around unity. So it is impossible to test the soun- Literature Cited dness of the data for the propylene-propadiene ) Ruhemann, M., "The Separation 1 of Gases", 2nd., system at 20.1℃ with Redlich-Kister's10) formula. Oxford Univ. Press, England (1949). x=1 2) Suda, S., Thesis of Dr. Eng., Tokyo Metropolitan University (Dec. 1966). logγ1/γ2=0 (4) x:=0 3) Reamer, H. H., Sage, B. H., Ind. Eng. Chem., 43, The solid lines in all figures and the determina- 1628 (1951). 4) Hanson, G. H., Hogan, R. J., Nelson, W. T., tion of azetropic points are based on a simple Cines, M. R. ibid., 44, 604 (1952). smoothing method using K values of the consti- 5) Mann, A. N., Pardee, W. A., Smyth, R. W., J. tuents. Chem. Eng. Data, 8, 499 (1963). 6) Hirata, M., Hakuta, T., Onoda, T., J. Petrol. Inst., 10, 440 (7), (1967). 5 Conclusion 7) Hill, A. B., McCormick, R. H., Barton, P., Fenske, M. R., A. I. Ch. E. Journal, 8, 681 (1962). The isothermal vapor-liquid equilibrium data 8) Horsley, L., " Azeotropic Data-II ", 32 (1962) Am. for the propylene-propane, propylene-propadiene Chem. Soc., Washington. 9) Hirata, M., Suda, S., Kagaku Kogaku, 31, 759 (1967). and propane-propadiene systems were obtained in 10) Redlich, O., Kister, T., Ind. Eng., Chem. 40, 345 this investigation.
Recommended publications
  • Liquid-Liquid Extraction
    OCTOBER 2020 www.processingmagazine.com A BASIC PRIMER ON LIQUID-LIQUID EXTRACTION IMPROVING RELIABILITY IN CHEMICAL PROCESSING WITH PREVENTIVE MAINTENANCE DRIVING PACKAGING SUSTAINABILITY IN THE TIME OF COVID-19 Detecting & Preventing Pressure Gauge AUTOMATIC RECIRCULATION VALVES Failures Schroedahl www.circor.com/schroedahl page 48 LOW-PROFILE, HIGH-CAPACITY SCREENER Kason Corporation www.kason.com page 16 chemical processing A basic primer on liquid-liquid extraction An introduction to LLE and agitated LLE columns | By Don Glatz and Brendan Cross, Koch Modular hemical engineers are often faced with The basics of liquid-liquid extraction the task to design challenging separation While distillation drives the separation of chemicals C processes for product recovery or puri- based upon dif erences in relative volatility, LLE is a fication. This article looks at the basics separation technology that exploits the dif erences in of one powerful and yet overlooked separation tech- the relative solubilities of compounds in two immis- nique: liquid-liquid extraction. h ere are other unit cible liquids. Typically, one liquid is aqueous, and the operations used to separate compounds, such as other liquid is an organic compound. distillation, which is taught extensively in chemical Used in multiple industries including chemical, engineering curriculums. If a separation is feasible by pharmaceutical, petrochemical, biobased chemicals distillation and is economical, there is no reason to and l avor and fragrances, this approach takes careful consider liquid-liquid extraction (LLE). However, dis- process design by experienced chemical engineers and tillation may not be a feasible solution for a number scientists. In many cases, LLE is the best choice as a of reasons, such as: separation technology and well worth searching for a • If it requires a complex process sequence (several quali ed team to assist in its development and design.
    [Show full text]
  • Selection of Thermodynamic Methods
    P & I Design Ltd Process Instrumentation Consultancy & Design 2 Reed Street, Gladstone Industrial Estate, Thornaby, TS17 7AF, United Kingdom. Tel. +44 (0) 1642 617444 Fax. +44 (0) 1642 616447 Web Site: www.pidesign.co.uk PROCESS MODELLING SELECTION OF THERMODYNAMIC METHODS by John E. Edwards [email protected] MNL031B 10/08 PAGE 1 OF 38 Process Modelling Selection of Thermodynamic Methods Contents 1.0 Introduction 2.0 Thermodynamic Fundamentals 2.1 Thermodynamic Energies 2.2 Gibbs Phase Rule 2.3 Enthalpy 2.4 Thermodynamics of Real Processes 3.0 System Phases 3.1 Single Phase Gas 3.2 Liquid Phase 3.3 Vapour liquid equilibrium 4.0 Chemical Reactions 4.1 Reaction Chemistry 4.2 Reaction Chemistry Applied 5.0 Summary Appendices I Enthalpy Calculations in CHEMCAD II Thermodynamic Model Synopsis – Vapor Liquid Equilibrium III Thermodynamic Model Selection – Application Tables IV K Model – Henry’s Law Review V Inert Gases and Infinitely Dilute Solutions VI Post Combustion Carbon Capture Thermodynamics VII Thermodynamic Guidance Note VIII Prediction of Physical Properties Figures 1 Ideal Solution Txy Diagram 2 Enthalpy Isobar 3 Thermodynamic Phases 4 van der Waals Equation of State 5 Relative Volatility in VLE Diagram 6 Azeotrope γ Value in VLE Diagram 7 VLE Diagram and Convergence Effects 8 CHEMCAD K and H Values Wizard 9 Thermodynamic Model Decision Tree 10 K Value and Enthalpy Models Selection Basis PAGE 2 OF 38 MNL 031B Issued November 2008, Prepared by J.E.Edwards of P & I Design Ltd, Teesside, UK www.pidesign.co.uk Process Modelling Selection of Thermodynamic Methods References 1.
    [Show full text]
  • Distillation Theory
    Chapter 2 Distillation Theory by Ivar J. Halvorsen and Sigurd Skogestad Norwegian University of Science and Technology Department of Chemical Engineering 7491 Trondheim, Norway This is a revised version of an article published in the Encyclopedia of Separation Science by Aca- demic Press Ltd. (2000). The article gives some of the basics of distillation theory and its purpose is to provide basic understanding and some tools for simple hand calculations of distillation col- umns. The methods presented here can be used to obtain simple estimates and to check more rigorous computations. NTNU Dr. ing. Thesis 2001:43 Ivar J. Halvorsen 28 2.1 Introduction Distillation is a very old separation technology for separating liquid mixtures that can be traced back to the chemists in Alexandria in the first century A.D. Today distillation is the most important industrial separation technology. It is particu- larly well suited for high purity separations since any degree of separation can be obtained with a fixed energy consumption by increasing the number of equilib- rium stages. To describe the degree of separation between two components in a column or in a column section, we introduce the separation factor: ()⁄ xL xH S = ------------------------T (2.1) ()x ⁄ x L H B where x denotes mole fraction of a component, subscript L denotes light compo- nent, H heavy component, T denotes the top of the section, and B the bottom. It is relatively straightforward to derive models of distillation columns based on almost any degree of detail, and also to use such models to simulate the behaviour on a computer.
    [Show full text]
  • Distillation ­ Accessscience from Mcgraw­Hill Education
    6/19/2017 Distillation ­ AccessScience from McGraw­Hill Education (http://www.accessscience.com/) Distillation Article by: King, C. Judson University of California, Berkeley, California. Last updated: 2014 DOI: https://doi.org/10.1036/1097­8542.201100 (https://doi.org/10.1036/1097­8542.201100) Content Hide Simple distillations Fractional distillation Vapor­liquid equilibria Distillation pressure Molecular distillation Extractive and azeotropic distillation Enhancing energy efficiency Computational methods Stage efficiency Links to Primary Literature Additional Readings A method for separating homogeneous mixtures based upon equilibration of liquid and vapor phases. Substances that differ in volatility appear in different proportions in vapor and liquid phases at equilibrium with one another. Thus, vaporizing part of a volatile liquid produces vapor and liquid products that differ in composition. This outcome constitutes a separation among the components in the original liquid. Through appropriate configurations of repeated vapor­liquid contactings, the degree of separation among components differing in volatility can be increased manyfold. See also: Phase equilibrium (/content/phase­equilibrium/505500) Distillation is by far the most common method of separation in the petroleum, natural gas, and petrochemical industries. Its many applications in other industries include air fractionation, solvent recovery and recycling, separation of light isotopes such as hydrogen and deuterium, and production of alcoholic beverages, flavors, fatty acids, and food oils. Simple distillations The two most elementary forms of distillation are a continuous equilibrium distillation and a simple batch distillation (Fig. 1). http://www.accessscience.com/content/distillation/201100 1/10 6/19/2017 Distillation ­ AccessScience from McGraw­Hill Education Fig. 1 Simple distillations. (a) Continuous equilibrium distillation.
    [Show full text]
  • Distillation Design the Mccabe-Thiele Method Distiller Diagam Introduction
    Distillation Design The McCabe-Thiele Method Distiller diagam Introduction • UiUsing r igorous tray-bby-tray callilculations is time consuming, and is often unnecessary. • OikhdfiifbOne quick method of estimation for number of plates and feed stage can be obtained from the graphical McCabe-Thiele Method. • This eliminates the need for tedious calculations, and is also the first step to understanding the Fenske-Underwood- Gilliland method for multi-component distillation • Typi ica lly, the in le t flow to the dis tilla tion co lumn is known, as well as mole percentages to feed plate, because these would be specified by plant conditions. • The desired composition of the bottoms and distillate prodillbifiddhiilldducts will be specified, and the engineer will need to design a distillation column to produce these results. • With the McCabe-Thiele Method, the total number of necessary plates, as well as the feed plate location can biddbe estimated, and some ifiinformation can a lblso be determined about the enthalpic condition of the feed and reflux ratio. • This method assumes that the column is operated under constant pressure, and the constant molal overflow assumption is necessary, which states that the flow rates of liquid and vapor do not change throughout the column. • To understand this method, it is necessary to first elaborate on the subjects of the x-y diagram, and the operating lines used to create the McCabe-Thiele diagram. The x-y diagram • The x-y diagram depi icts vapor-liliqu id equilibrium data, where any point on the curve shows the variations of the amount of liquid that is in equilibrium with vapor at different temperatures.
    [Show full text]
  • Minimum Reflux Ratio
    Chapter 4 Total Reflux and Minimum Reflux Ratio a. Total Reflux . In design problems, the desired separation is specified and a column is designed to achieve this separation. In addition to the column pressure, feed conditions, and reflux temperature, four additional variables must be specified. Specified Variables Designer Calculates Case A D, B: distillate and bottoms flow rates 1. xD QR, QC: heating and cooling loads 2. xB N: number of stages, Nfeed : optimum feed plate 3. External reflux ratio L0/D DC: column diameter 4. Use optimum feed plate xD, xB = mole fraction of more volatile component A in distillate and bottoms, respectively The number of theoretical stages depends on the reflux ratio R = L0/D. As R increases, the products from the column will reduce. There will be fewer equilibrium stages needed since the operating line will be further away from the equilibrium curve. The upper limit of the reflux ratio is total reflux, or R = ∞. The rectifying operating line is given as R 1 yn+1 = xn + xD R +1 R +1 When R = ∞, the slop of this line becomes 1 and the operating lines of both sections of the column coincide with the 45 o line. In practice the total reflux condition can be achieved by reducing the flow rates of all the feed and the products to zero. The number of trays required for the specified separation is the minimum which can be obtained by stepping off the trays from the distillate to the bottoms. Figure 4.4-8 Minimum numbers of trays at total reflux.
    [Show full text]
  • I. an Improved Procedure for Alkene Ozonolysis. II. Exploring a New Structural Paradigm for Peroxide Antimalarials
    University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Student Research Projects, Dissertations, and Theses - Chemistry Department Chemistry, Department of 2011 I. An Improved Procedure for Alkene Ozonolysis. II. Exploring a New Structural Paradigm for Peroxide Antimalarials. Charles Edward Schiaffo University of Nebraska-Lincoln Follow this and additional works at: https://digitalcommons.unl.edu/chemistrydiss Part of the Organic Chemistry Commons Schiaffo, Charles Edward, "I. An Improved Procedure for Alkene Ozonolysis. II. Exploring a New Structural Paradigm for Peroxide Antimalarials." (2011). Student Research Projects, Dissertations, and Theses - Chemistry Department. 23. https://digitalcommons.unl.edu/chemistrydiss/23 This Article is brought to you for free and open access by the Chemistry, Department of at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Student Research Projects, Dissertations, and Theses - Chemistry Department by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. I. An Improved Procedure for Alkene Ozonolysis. II. Exploring a New Structural Paradigm for Peroxide Antimalarials. By Charles E. Schiaffo A DISSERTATION Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Doctor of Philosophy Major: Chemistry Under the Supervision of Professor Patrick H. Dussault Lincoln, Nebraska June, 2011 I. An Improved Procedure for Alkene Ozonolysis. II. Exploring a New Structural Paradigm for Peroxide Antimalarials. Charles E. Schiaffo, Ph.D. University of Nebraska-Lincoln, 2011 Advisor: Patrick H. Dussault The use of ozone for the transformation of alkenes to carbonyls has been well established. The reaction of ozone with alkenes in this fashion generates either a 1,2,4- trioxolane (ozonide) or a hydroperoxyacetal, either of which must undergo a separate reduction step to provide the desired carbonyl compound.
    [Show full text]
  • Effect of Pressure on Distillation Separation Operation
    Solutions for R&D to Design PreFEED Effect of Pressure on Distillation Separation Operation April 30, 2012 PreFEED Corporation Hiromasa Taguchi Solutions for R&D to Design 1 PreFEED Introduction Generally, it is known that, for distillation, separation tends to be enhanced by lower pressures. For two components, the ease of distillation separation can be judged from the value of the relative volatility (α). Here, we will take typical substances as examples and examine the effect of pressure changes on their relative volatilities. Solutions for R&D to Design 2 PreFEED Ideal Solution System The relative volatility (α) is a ratio of vapor-liquid equilibrium ratios and can be expressed by the following equation: K1 y1 y2 K1 , K2 K2 x1 x2 In the case of an ideal solution system , using Raoult’s law, the relative volatility can be expressed as a ratio of vapor pressures. Py x Po 1 1 1 Raoult’s law Py x Po o 2 2 2 K1 P1 y Po o K 1 1 K2 P2 1 x1 P o y2 P2 K2 x2 P Solutions for R&D to Design 3 PreFEED Methanol-Ethanol System As an example of an ideal solution system , let’s consider a methanol-ethanol binary system. α is calculated by obtaining vapor pressures from the Antoine constants in the table below. 0 B 2.8 ln(Pi [Pa]) A 2.6 C T[K] 2.4 ABC 2.2 Methanol 23.4803 3626.55 -34.29 2 Ethanol 23.8047 3803.98 -41.68 1.8 As the temperature (saturated 1.6 pressure) decreases, the value of 1.4 α increases.
    [Show full text]
  • Acid Dissociation Constant - Wikipedia, the Free Encyclopedia Page 1
    Acid dissociation constant - Wikipedia, the free encyclopedia Page 1 Help us provide free content to the world by donating today ! Acid dissociation constant From Wikipedia, the free encyclopedia An acid dissociation constant (aka acidity constant, acid-ionization constant) is an equilibrium constant for the dissociation of an acid. It is denoted by Ka. For an equilibrium between a generic acid, HA, and − its conjugate base, A , The weak acid acetic acid donates a proton to water in an equilibrium reaction to give the acetate ion and − + HA A + H the hydronium ion. Key: Hydrogen is white, oxygen is red, carbon is gray. Lines are chemical bonds. K is defined, subject to certain conditions, as a where [HA], [A−] and [H+] are equilibrium concentrations of the reactants. The term acid dissociation constant is also used for pKa, which is equal to −log 10 Ka. The term pKb is used in relation to bases, though pKb has faded from modern use due to the easy relationship available between the strength of an acid and the strength of its conjugate base. Though discussions of this topic typically assume water as the solvent, particularly at introductory levels, the Brønsted–Lowry acid-base theory is versatile enough that acidic behavior can now be characterized even in non-aqueous solutions. The value of pK indicates the strength of an acid: the larger the value the weaker the acid. In aqueous a solution, simple acids are partially dissociated to an appreciable extent in in the pH range pK ± 2. The a actual extent of the dissociation can be calculated if the acid concentration and pH are known.
    [Show full text]
  • AP42 Chapter 9 Reference
    Background Report Reference AP-42 Section Number: 9.2.2 Background Chapter: 4 Reference Number: 22 Title: "Critical Review of Henry's Law Constants fro Pesticides" in Reviews of Environmental Contamination and Toxicology L.R. Suntio 1988 AP-42 Section 9! Reference Report Sect. 3c L2% Critical Review of Henry's Law Constants Reference for Pesticides L.R. Sunti0,'W.Y. Shiu,* D. Mackay,* J.N. Seiber,** and D. Glotfelty*** Contents ......... ........... ........... ............. IV. Data Analysis ........ ........... ......... I V. Discussion .......... ........... .......... 41 ............. so .......... ............ I. Introduction Pesticides play an important role in maintaining agricultural productivity, but they may also be causes of contamination of air, water, soil, and food, with possible adverse effects on human and animal health. The proper use of pesticide chemicals must be based on an understanding of the behavior of the chemicals as they interact with air, water, soil, and biota, react or degrade, and migrate. This behavior is strongly influenced by the chemicals' physical- chemical properties of solubility in water, vapor pressure or volatility, and tendency to sorb to organic and mineral matter in the soil. Reviews of such physical-chemical properties have been compiled by Kenaga (1980), Kenaga and Goring (1980), Briggs (1981), and Bowman and Sans (1983) for aqueous solubility, octanol-water partition coefficient, bio- accumulation, and soil sorption; Spencer and Cliath (1970, 1973. 1983). and Spencer (1976) for vapor pressure and volatilization from soil. In this chapter we compile and discuss data for Henry's Law constant H (which is the ratio of solute partial pressure in the air to the equilibrium water concentration and thus has units of Pa m3/mol) or the air-water partition 'Department ofchemical Engineering and Applied Chemistry.
    [Show full text]
  • Energy Efficient Trace Removal by Extractive Distillation
    Energy efficient trace removal by extractive distillation Citation for published version (APA): Jongmans, M. T. G. (2012). Energy efficient trace removal by extractive distillation. Technische Universiteit Eindhoven. https://doi.org/10.6100/IR732573 DOI: 10.6100/IR732573 Document status and date: Published: 01/01/2012 Document Version: Publisher’s PDF, also known as Version of Record (includes final page, issue and volume numbers) Please check the document version of this publication: • A submitted manuscript is the version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal.
    [Show full text]
  • A Study of the Reversing of Relative Volatilities by Extractive Distillation
    A study of the reversing of relative volatilities by extractive distillation by An-I Yeh A thesis submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Chemical Engineering Montana State University © Copyright by An-I Yeh (1986) Abstract: The separation of the close-boiling mixture, m-xylene-o-xylene; three binary azeotropes: ethanol-water, methyl acetate-methanol, acetone-methanol, and four ternary azeotropes: n-propyl acetate-n-propanol-water, isopropyl acetate-isopropanol-water, n—butyl acetate-n- butanol-water, isobutyl acetate-isobutanol-water has been enhanced by extractive distillation. The azeotropes have been negated and the relative volatilities of key components have been reversed by the agents used. The plot of polar interaction versus hydrogen bonding, called polarity diagram, was used to compare the affinity of agents for key components. Thus the key component which will be the overhead product can be predicted. The three solubility parameters were used to describe the intermolecular forces occurring between agents and key components in extractive distillation. The MOSCED model was used to calculate the activity coefficients of the key components using the properties of the pure compounds. The calculated values fitted the experimental data well. The advantage of this model was to calculate the. relative volatilities of key components in the presence of the agent using the properties of pure compounds instead of using the properties of mixtures. Temperature inversion, where the overhead temperature was higher than the stillpot temperature, was observed for the acetone-methanol system when ketones were used as the agents. The data showed that the temperature inversion could be caused by the dissolving of the vapor of key components in the liquid agents.
    [Show full text]