Recuperação De Sesquiterpenos Do óleo-resina De Copaíba A Partir Da Destilação Molecular

Copaiba oil-resin has aromatic characteristics and pharmacological activities attributed to sesquiterpenes compounds. These purified compounds present application in perfume, pharmaceutical and cosmetic industries. Therefore, the objective of this work was to use molecular distillation to recover and purify sesquiterpenes of the copaiba oil-resin with purity high. The parameters evaporator temperature (TEV) from 45 to 100 °C and feed flow rate (Q) between 15 and 30 ml min-1 were evaluated through design of experiments (22 with center points). The results showed that it was possible to recover sesquiterpenes with 98.12% purity in the distillate stream. Increased in TEV and reduction in Q were the effects observed experimentally and through the response surface. The best experimental condition was TEV of 100 °C and Q of 15 mL min-1. Collor differences were noticed between distillate streams (colorless) and residue (brown). These can be used as parameters for separation of sesquiterpenes and diterpenes. The molecular distillation proved to be an efficient processo to both recovery and purification of sesquiterpenes from the copaiba oil-resin.39779580

Characterization Of Thermodynamic Systems To Separation Process Applications

This work is concerned with developing the tools which enable complex multidimensional relationships between vapour and liquid phases in thermodynamic equilibrium to be represented in a form which facilitates appreciation of the complex structure so that the nature of optimum solutions is more clearly understood. The detailed analysis will be based on ternary mixtures in order to provide a basis for physical interpretation and to give a complete description of the system. Still, the development of an interactive graphics-based approach to the design of multistage separation processes is presented and illustrated by reference to ternary distillation systems. It focuses attention on how design and operational decisions can be taken based on the identification of the fundamental patterns of interaction between the variables and how they relate to operational performance. The importance of the relative positioning of the operating line and equilibrium surface provides insight as to the local factors which determine the performance of the equipment. It provides a basis for determining practical values of minimum reflux ratios for a multicomponent system where only partial information is given on the product compositions.18SUPPLS81S8

Excess Gibbs Free Energies Of (n-hexane + Propan-1-ol) At 338.15 And 348.15 K And Of (n-hexane + Propan-2-ol) At 323.15, 338.15, And 348.15 K

The (vapor + liquid) phase equilibria of (n-hexane + propan-1-ol) at 338.15 and 348.15 K and of (n-hexane + propan-2-ol) at 323.15, 338.15, and 348.15 K have been measured using a Fischer recirculating still. Excess molar Gibbs energies Gm E were calculated. Thermodynamic consistency was tested by two methods and the results were correlated by use of the Wilson equation. Both mixtures exhibit positive Gm E values in the temperature range studied. © 1988.205539544Van Ness, Soczek, Peloquin, Machado, (1967) J. Chem. Eng. Data, 12, p. 217Brown, Fock, Smith, (1969) J. Chem. Thermodynamics, 1, p. 273Sayegh, Ratcliff, (1976) J. Chem. Eng. Data, 21, p. 71Brown, Waldemar, (1979) J. Chem. Eng. Data, 24, p. 319Berro, Neau, (1981) Fluid Phase Equilibria, 7, p. 41Schmelzer, Lieberwirth, (1982) Fluid Phase Equilibria, 9, p. 67Stage, Fischer, (1968) GIT Fachz. Lab., 12, p. 1167Timmermans, (1965) Physico-Chemical Constants of Pure Organic Compounds, 2. , Elsevier, AmsterdamAmbrose, Sprake, (1970) J. Chem. Thermodynamics, 2, p. 631Van Ness, (1964) Classical Thermodynamics of Non-Electrolyte Solutions, p. 122. , Pergamon Press, OxfordTsonopoulos, (1974) AIChE J., 20, p. 263Prausnitz, Anderson, Grens, Eckert, Hsieh, O'Connell, (1980) Computer Calculations for Multicomponent Vapor-Liquid and Liquid-Liquid Equilibria, p. 138. , Prentice-Hall, New JerseyPrausnitz, (1969) Molecular Thermodynamics of Fluid-Phase Equilibria, p. 217. , Prentice-Hall, New JerseyModell, Reid, (1974) Thermodynamics and its Applications, p. 328. , Prentice-Hall, New JerseyGiordano, (1985) M.Sc. Thesis, , State University of Campinas, Campinas, BrazilOrye, Prausnitz, MULTICOMPONENT EQUILIBRIA—THE WILSON EQUATION (1965) Industrial & Engineering Chemistry, 57, p. 1

Evaluation Of The Dynamic Behavior Of An Extractive Distillation Column For Dehydration Of Aqueous Ethanol Mixtures

The dynamic characteristics of an extractive distillation column for dehydration of aqueous ethanol mixture are investigated. The objective is to analyse the sensibility and stability of the process to perturbations in its main variables to be possible to recommend the best variables to be manipulated. Taking this into account, it was developed a model which considers the main phenomena taking place, i. e. it incorporates the effects of simultaneous mass and heat transfers as well as hydraulic behavior of the plates. Furthermore, it contains a rigorous consideration of the phase equilibria representation, once, in this case, the system is highly non-ideal. The mathematical modeling results in a system of differential equations which is solved by Gear's procedure. The dynamic behavior was analysed from the knowledgment of the effect of composition variation of the feed stream, rate of solvent and reflux flow rate. The quality of the final product can be achieved manipulating the solvent flow rate once the temperature of the upper part of the column, p.e., plate 18 and 22, is very sensitive to the performed modifications. © 1995.19SUPPL. 1405408Black, Distillation Modeling of Ethanol Recovery and Dehydration Processes for Ethanol and Gasohol (1980) Chem. Eng. Progr., 76 (9), p. 78Gallun, Holland, Gear's Procedure for The Simultaneous Solution of Differential and Algebraic Equation With Aplication to Unsteady State Distillation Problems (1982) Computers Chem. Engng, 30, p. 3Gani, Ruiz, Cameron, A Generalized Model for Distillation Columns-I (1986) Computers & Chemical Engineering, 10, p. 3Gear, (1971) Numerical Initial Value Problems in Ordinary Differential Equations, , Prentice Hall, Englewwod Cliffs, NJLee, Pahl, Solvent Screening Study and Conceptual Extractive Distillation Process to Produce Anhydrous Ethanol From Fermentation Broth (1985) Ind. Eng. Chem. Proc. Des. Dev., 24, p. 168Lynn, Hanson, Multieffect Extractive Distillation For Separating Aqueous Azeotropes (1986) Eng. Eng. Chem. Proc. Des. Dev., 25, p. 936Maciel, (1989) PhD thesis, , Leeds University, England, U. KMagnussen, Michelsen, Fredenslund, Azeotropic Distillation Using UNIFAC (1979) Inst. Chem. E. symp. Ser., 56, p. 4.2. , Int. Symp. on Distillation, ICE Rugby, Warwickshire, EnglandMartini, (1995) M. Sc. Thesis, , UNICAMP, SP, BrasilMeirelles, Weiss, Herfurth, Ethanol Deydration By Extractive Distillation (1992) J. Chem. Tech. Biotechnol., 53, p. 268Prokopakis, Seider, Feasible Specifications in Azeotropic Distillation (1983) AIChE J., 29, p. 49Rovaglio, Doherty, Dynamics of Heterogeneous Azeotropic Distillation Columns (1990) AIChE Journal, 36, p.

Vapor-liquid Phase Equilibrium Measurements For The N-hexane-1-butanol System At 323.15,338.15 And 348.15 K

The vapor-liquid phase equilibria for the n-hexane-1-butanol system at 323.15, 338.15, and 348.15 K have been measured using a Fischer recirculating still. Excess molar Gibbs energies GEPm and activity coefficients were calculated. Thermodynamic consistency was tested by two methods and the results were correlated by use of the Wilson equation. The system exhibits positive GE m values over the entire composition range in the temperature range studied and an azeotrope exists at all three measured temperatures. © 1989.501-2201208Berro, Rogalski, Péneloux, Excess Gibbs energies and excess volumes of 1-butanol + n-hexane and 2-methyl-1-propanol + n-hexane binary systems (1982) Journal of Chemical & Engineering Data, 27, pp. 353-355Boublík, Fried, Hála, (1973) The Vapour Pressures of Pure Substances, , Elsevier, New YorkBrown, Fock, Smith, The thermodynamic properties of solutions of normal and branched alcohols in benzene and n-hexane (1969) J. Chem. Thermodyn., 1, pp. 273-291Maciel, Francesconi, Excess Gibbs free energies of (n-hexane + propan-1-ol) at 338.15 and 348.15 K and of (n-hexane + propan-2-ol) at 323.15, 338.15 and 348.15 K. (1988) J. Chem. Thermodyn., 20, pp. 539-544Modell, Reid, (1974) Thermodynamics and Its Application, , Prentice-Hall, Englewood Cliffs, NJMonfort, Vapor—liquid equilibria for benzene—acetonitrile and toluene— acetonitrile mixtures at 343.15 K. (1983) J. Chem. Eng. Data, 28, pp. 24-27Nath, Bender, On the thermodynamics of associated solutions. I. An analytical method for determining the enthalpy and entropy of association and equilibrium constant for pure liquid substances (1981) Fluid Phase Equilibria, 7, pp. 275-287Orye, Prausnitz, Multicomponent equilibria with the Wilson equation (1965) Industrial & Engineering Chemistry, 57, pp. 19-26Patai, Zabicky, Rappoport, Table of physical properties of organic compounds (1977) CRC Handbook of Chemistry and Physics, , R.C. Weast, CRC, Press, Boca Raton, FL, Section CPrausnitz, (1969) Molecular Thermodynamics of Fluid-Phase Equilibria, , Prentice-Hall, Englewood Cliffs, NJPrausnitz, Anderson, Grens, Eckert, Hsieh, O'Connel, (1980) Computer Calculations for Multicomponent Vapor—Liquid and Liquid—Liquid Equilibria, , Prentice-Hall, Englewood Cliffs, NJSmirnova, Kurtynina, Thermodynamic functions of mixing for a number of binary alcohol—hydrocarbon solutions (1969) Russ. J. Phys. Chem., 43, pp. 1059-1060Tsonopoulos, An empirical correlation of second virial coefficients (1974) Am. Int. Chem. Eng. J., 20, pp. 263-272Van, (1964) Classical Thermodynamics of Non-Electrolyte Solutions, , Pergamon, OxfordVan, Soczek, Peloquin, Machado, Thermodynamic excess properties of three alcohol—hydrocarbon systems (1967) Journal of Chemical & Engineering Data, 12, pp. 217-224Wieczorek, Stecki, Vapour pressures and thermodynamic properties of hexan-1-ol + n-hexane between 298.230 and 342.824 K (1978) J. Chem. Thermodyn., 10, pp. 177-18

Modeling, Simulation And Analysis Of Molecular Distillators: Centrifugal And Falling Film

A description of the molecular distillation process is made in order to show its principal applications for chemical processes. The transfer process from liquid stage for the falling film and centrifugal molecular distillators is described. The liquid film flows in the conic rotative evaporator of the centrifugal distillator and in the cylindric evaporator of the falling film distillator. The equations that characterize both processes are the mass, energy and momentum balances and the Langmuir rate of evaporation. The equations are solved by the method of finite differences. The effect of several parameters on the distillation rate and on the separation efficiency are studied for binary systems. A comparative analysis between the falling film and centrifugal distillation apparatuses is carried out.20SUPPL.1S19S24Batistella, C.B., (1995) Master's Thesis, , UNICAMP, Campinas-SP, BrasilBhandarkar, M., Ferron, J.R., Transport Process in Thin Liquid Films during High-Vacuum Distillation (1988) Ind. Eng. Chem. Res., 27, pp. 1016-1024Carnahan, B., Luther, H.A., Wilkes, J.O., (1969) Applied Numerical Methods, pp. 440-442. , John Wiley & Sons, IncKawala, Z., (1983) Kinetik der Oberflachenverdamfung Unter Den Bedingungen der Molekulardestillation, , Wydawnictwo Politechniki Wroclawskiej, WroclawKawala, Z., Stephan, K., Evaporation Rate and Separation Factor of Molecular Distillation in a Falling Film Apparatus (1989) Chem. Eng. Tech., 12, pp. 406-413Perry, R.H., Chilton, C.H., (1980) Manual de Engenharia Quimica, pp. 50-55. , Ed. Guanabara dois (Rio de Janeiro), section 1

Evaluation On Numerical Methods For Resolution Of Stiff Systems

Batch distillation process is characterized as being highly flexible, handling a wide range of different mixtures, feed compositions, number of components, changes in product demands and availability of shared storage. Unlike continuous distillation, batch distillation is inherently an unsteady state process and therefore the modelling of such columns is dynamic in nature. This generates a set of differential-algebraic equations (DAE) which is very stiff. In this work, the numerical integration of the system of differential equations is made by using Euler method, Runge-Kutta 4 th. order with variable step method and the semi-implicit method of Villadsen and Michelsen. All of them are compared using different degrees of stiffness. This result is very important to be used in on-line control purposes.76SUPPL. 2607608Boston, J.F., Britt, H.I., Jirapongphan, S., Shan, V.B., An Advanced System for the Simulation of Batch Distillation (1980) Chem. Proc. Design, pp. 203-237Cuille, P.E., Reklaitis, G.V., Dynamic Simulation of Multicomponent Batch Reticfication with Chemical Reactions (1986) Comput. Chem. Engng., 10, pp. 389-394Luz Jr., L.F.L., Maciel, M.R.W., (1992) Model., Polit, e Otim. de Col. Destil. Em Batelada, , 9o. COBEQ, BrazilLuz Jr., L.F.L., (1993), Master Thesis, UNICAMP, Campinas, SP, BrazilVilladsen, J., Michelsen, M.L., (1978) Solution of Differential Equations Models by Polynomial Aproximations, , Prentice-Hall In

Rigorous Modeling And Simulation Of Molecular Distillators: Development Of A Simulator Under Conditions Of Non Ideality Of The Vapor Phase

In this work, a more rigorous model of the vapor phase was considered in characterizing the molecular distillation more realistically. The model used here tries to predict the behavior of the molecular distillation in terms of several factors that, in a considerable way, influence the evaporation efficiency, e.g. design of the molecular distillators in relation to the distance between the evaporator and the condenser and their geometries, pressure of the system, and condensation temperature. This model was developed in the literature by several authors. The objective here is to consider it in the DISMOL software (developed by the authors of this work) taking into account the main contributions available. (C) 2000 Elsevier Science Ltd.In this work, a more rigorous model of the vapor phase was considered in characterizing the molecular distillation more realistically. The model used here tries to predict the behavior of the molecular distillation in terms of several factors that, in a considerable way, influence the evaporation efficiency, e.g. design of the molecular distillators in relation to the distance between the evaporator and the condenser and their geometries, pressure of the system, and condensation temperature. This model was developed in the literature by several authors. The objective here is to consider it in the DISMOL software (developed by the authors of this work) taking into account the main contributions available.2402/07/1513091315Batistella, C.B., (1996), M.Sc. thesis. LDPS Campinas-SP, Brasil: UNICAMPBatistella, C.B., Maciel, M.R.W., Modeling, simulation and analysis of molecular distillators: Centrifugal and falling film (1996) Computers & Chemical Engineering, 20 (SUPPL.), pp. S19-S24Bhandarkar, M., Ferron, J.R., Simulation of rarefied vapor flows (1991) Industrial & Engineering Chemistry Research, 30, pp. 998-1007Bird, G.A., Direct simulation and the Boltzmann equation (1970) The Physics of Fluids, 13, pp. 2676-2681Bird, G.A., (1976) Molecular Gas Dynamics, , Oxford, UK: Clarendon PressBird, G.A., (1994) Molecular Gas Dynamics and the Direct Simulation of Gas Flows, , Oxford, UK: Clarendon PressBorgnakke, C., Larsen, P.S., Statistical collision model for Monte Carlo simulation of polyatomic gas mixture (1975) Journal of Computational Physics, 18, pp. 405-420Ferron, J.R., Evaporation and condensation of mixture under rarefied conditions (1986) Industrial & Engineering Chemistry Fundamentals, 25, pp. 594-602Lutisãn, J., Cvengrõs, J., Mean free path of molecules on molecular distillation (1995) Chemical Engineering Journal, 56, pp. 39-50Lutisãn, J., Cvengrõs, J., Effect of inert gas pressure on the molecular distillation process (1995) Separation Science & Technology, 30 (17), pp. 3375-3389Oran, E.S., Oh, C.K., Cybyk, B.Z., Direct simulation Monte Carlo: Recent advances and applications (1998) Annual Review of Fluid Mechanics, 30, p. 40

Simulation Of Distillation Process In The Bioethanol Production Using Nonequilibrium Stage Model

Most models available for simulation of multicomponent separation processes are based on the idealized concept of equilibrium or theoretical stages. However, accuracy of the predictions can be highly enhanced if a nonequilibrium stage model is taken into account. In this work, hydrous bioethanol production process was simulated using Aspen Plus®considering three calculation methods: equilibrium, equilibrium with constant plate efficiency and nonequilibrium stage models. Comparison of nonequilibrium and equilibrium model simulations, assuming the same number of stages, showed that energy consumption calculated is much larger when nonequilibrium model is considered and that column specifications have to be adapted in order to achieve bioethanol specification. Equilibrium model with efficiency of 70% presented a satisfactory agreement with nonequilibrium model. © 2009 Elsevier B.V. All rights reserved.27C735740Eckert, E., Vanek, T., Some aspects of rate-based modelling and simulation of three-phase distillation columns (2001) Computers and Chemical Engineering, 25 (4-6), pp. 603-612. , DOI 10.1016/S0098-1354(01)00640-8, PII S0098135401006408Gmehling, J., Onken, U., (1977) Vapor-Liquid Equilibrium Data Collection - DECHEMA Chemistry Data SeriesKrishnamurthy, R., Taylor, R., Nonequilibrium stage model of multicomponent separation processes. Part I: Model description and method of solution (1985) AIChE Journal, 31 (3), pp. 449-456Pescarini, M.H., Barros, A.A.C., Wolf-Maciel, M.R., Development of a software for simulating separation processes using a nonequilibrium stage model (1996) Computers & Chemical Engineering, 20, pp. 279-284. , SUPARepke, J.U., Villain, O., Wozny, G., A nonequilibrium model for three-phase distillation in a packed column: Modelling and experiments (2004) Computers & Chemical Engineerings, 28, pp. 775-780Springer, P.A.M., Van Der Molen, S., Krishna, R., The need for using rigorous rate-based models for simulations of ternary azeotropic distillation (2002) Computers & Chemical Engineering, 26, pp. 1265-127