scispace - formally typeset
Search or ask a question

Showing papers in "Industrial & Engineering Chemistry Research in 1987"


Journal ArticleDOI
TL;DR: In this paper, the parameters for 46 group combinations are provided and a new main group for sulfones is introduced, for which the group interaction parameters for eight main groups are fitted.
Abstract: The group contribution method UNIFAC has become very popular because of its large range of applicability and its reliable predictions of vapor−liquid equilibria. With the help of new data stored in the Dortmund Data Bank (DDB), many gaps in the existing UNIFAC parameter matrix have been filled, and many new main groups have been added to the parameter table. In this paper, the parameters for 46 group combinations are provided. Additionally, a new main group for sulfones is introduced, for which the group interaction parameters for eight main groups are fitted.

1,135 citations



Journal ArticleDOI
TL;DR: Modification de la methode UNIFAC de telle maniere que l'equilibre liquide-vapeur, les coefficients d'activites pour des dilutions infinies and les enthalpies de melange puissent etre calcules suffisamment exactement avec un seul set of parametres as discussed by the authors.
Abstract: Modification de la methode UNIFAC de telle maniere que l'equilibre liquide-vapeur, les coefficients d'activites pour des dilutions infinies et les enthalpies de melange puissent etre calcules suffisamment exactement avec un seul set de parametres

703 citations


Journal ArticleDOI
TL;DR: In this article, a condensation rapide technique is used for composes mineraux ou organiques, which traverses a buse resulte de la nucleation de la solution and du processus de croissance des particules.
Abstract: La condensation rapide qui a lieu pendant l'expansion rapide d'un fluide supercritique a travers une buse resulte de la nucleation de la solution et du processus de croissance des particules. Cette technique est utilisee pour des composes mineraux ou organiques

398 citations


Book ChapterDOI
TL;DR: In this paper, l'oxydation catalytique heterogene des composes volatils organiques: principes scientifiques fondamentaux de toutes les oxydations catalytiques et application aux composes VOLATILS organiques.
Abstract: Revue de la litterature sur l'oxydation catalytique heterogene des composes volatils organiques: principes scientifiques fondamentaux de toutes les oxydations catalytiques et application aux composes volatils organiques

364 citations


Journal ArticleDOI
TL;DR: Tres forte augmentation de solubilite dans certains cas (6 fois pour l'acide aminobenzoique dans CO 2 avec addition de methanol) Interpretation par les interactions intermoleculaires
Abstract: Tres forte augmentation de solubilite dans certains cas (6 fois pour l'acide aminobenzoique dans CO 2 avec addition de methanol). Interpretation par les interactions intermoleculaires

301 citations


Journal ArticleDOI
TL;DR: In this article, an equality relaxation variant to the outer-approximation algorithm for solving mixed-integer nonlinear programming (MINLP) problems that arise in structural optimization of process flowsheets is presented.
Abstract: "This paper presents an Equality Relaxation variant to the Outer-Approximation algorithm for solving mixed-integer nonlinear programming (MINLP) problems that arise in structural optimization of process flowsheets. The propsed algorithm has the important capability of being able to explicitly handle nonlinear equations within MINLP formulations that have linear integer variables and linear/nonlinear continuous varibales. It is shown that through the explicit treatment of nonlinear equations, the proposed algorithm avoids computational difficulties (e.g. singularities, destruction of sparsity) that are experienced with algebraic or numerical elimination schemes.Also, theoretical properties of the Equality-Relaxation algorithm are discussed, and its performance is demonstrated with a planning problem and a flowsheet synthesis problem. Finally, a simple procedure for structural sensitivity analysis is presented."

266 citations


Journal ArticleDOI
TL;DR: In this article, the authors examine a set of exemples a deux dimensions and examine plusieurs ex-emples with de two dimensions, i.e., 2D and 3D.
Abstract: Probleme du choix optimal du systeme de reacteurs en ecoulement permanent pour une serie de reactions ayant chacune une cinetique donnee. On s'interesse aux systemes isothermes sans changement de volume sur la reaction et le melange. On ne peut pas combiner ensemble les reacteurs parfaitement agites, les reacteurs piston ou les reacteurs a recyclage pour etendre la region accessible. On examine plusieurs exemples a deux dimensions

240 citations


Journal ArticleDOI
TL;DR: In this paper, a closed-loop system with an inverse-based controller is shown to be very sensitive to diagonal input uncertainty, but the controller does not correct for the strong directionality of the plant and may therefore give poor performance.
Abstract: Large elements in the RGA imply a plant which is fundamentally difficult to control. (1) The plant is very sensitive to uncorrelated uncertainty in the transfer matrix elements. (2) The closed-loop system with an inverse-based controller is very sensitive to diagonal input uncertainty. With a diagonal controller, the system is not sensitive to diagonal input uncertainty, but the controller does not correct for the strong directionality of the plant and may therefore give poor performance even without uncertainty.

237 citations



Journal ArticleDOI
TL;DR: In this article, a propriete for thermodynamique de non-equilibre classique: relations lineaires flux-force and relations de reciprocite d'Onsager.
Abstract: Dans un dispositif de contact ou de separation comprenant une aire de transfert donnee et effectuant un transfert specifie, l'entropie totale produite est minimale lorsque la vitesse locale de production d'entropie est uniformement repartie (equiseparee) le long des variables spatiales et/ou temporelles. Cette propriete est demontree pour les conditions de thermodynamique de non-equilibre classique: relations lineaires flux-force et relations de reciprocite d'Onsager. On montre que les procedes «equisepares» sont optimaux au sens economique, c'est-a-dire qu'ils correspondent au minimum de quelque fonction de cout


Journal ArticleDOI
TL;DR: Mise en place d'une procedure de commande simple which utilise la methode "autotune" d'Astrom for obtenir les gains and les frequences critiques for chaque element diagonal de la matrice des fonctions de transfert as discussed by the authors.
Abstract: Mise en place d'une procedure de commande simple qui utilise la methode «autotune» d'Astrom pour obtenir les gains et les frequences critiques pour chaque element diagonal de la matrice des fonctions de transfert. Il ne faut que N tests pour un systeme a N×N variable. La procedure, testee sur un exemple, est efficace

Journal ArticleDOI
TL;DR: In this article, a generalized empirical correlation has been proposed to predict physical properties of pure hydrocarbons and undefined petroleum fractions, such as critical temperature, critical pressure, critical volume, and heat of vaporization.
Abstract: A generalized empirical correlation has been proposed to predict physical properties of pure hydrocarbons and undefined petroleum fractions. Properties such as critical temperature (T/sub c/), critical pressure (P/sub c/), critical volume (V/sub c/), molecular weight (M), normal boiling point (T/sub b/), specific gravity (S), refractive index (n), carbon-to-hydrogen weight ratio (CH), and heat of vaporization (..delta..H/sub v/) may be predicted from any pair of available characterizing parameters (T/sub b/,S), (T/sub b/,I), (T/sub b/, CH), (M,S), (M,I), (M,CH), (v/sub 1/,S), (v/sub 1/,I), or (v/sub 1/,CH) as input parameters. Proposed correlations are generally superior or at least equivalent to the existing correlations.

Journal ArticleDOI
TL;DR: In this article, the bleu de phenol was utilised for determiner les interactions dipole-dipole et acide-base, l'induction and la dispersion des fluides supercritiques d'ethylene, de chlorotrifluoromethane and de fluoroforme.
Abstract: Utilisation du bleu de phenol pour determiner les interactions dipole-dipole et acide-base, l'induction et la dispersion des fluides supercritiques d'ethylene, de chlorotrifluoromethane et de fluoroforme



Journal ArticleDOI
TL;DR: A two-phase approach for on-line optimization of chemical processes was proposed by a previous author as discussed by the authors, which addresses some crucial difficulties encountered with chemical processes such as imperfect models, nonlinearity, presence of operating constraints, and the multivariable nature of most processes.
Abstract: A two-phase approach for on-line optimization of chemical processes was proposed by a previous author. This approach addresses some crucial difficulties encountered with chemical processes such as imperfect models, nonlinearity, presence of operating constraints, and the multivariable nature of most processes. The approach was adapted for application to an industrial scale problem, namely, the optimal operation of a packed tubular reactor for the production of ethylene oxide. This application exhibits many characteristics cited above which makes on-line optimization a challenging problem. Results using a simulation study show that the two-phase approach holds considerable promise. The paper concludes with suggestions regarding the application of the proposed approach to industrial processes.



Journal ArticleDOI
TL;DR: In this article, a methodes de mesure rapide des isothermes de coadsorption par chromatographie liquide haute performance frontale is described.
Abstract: Description de 2 methodes de mesure rapide des isothermes de coadsorption par chromatographie liquide haute performance frontale

Journal ArticleDOI
TL;DR: In this paper, the authors consider two different effects of disturbance directions on closed-loop performance: the first is in terms of the magnitude of the manipulated variables m needed to cancel the influence of the disturbance on the process output completely at steady state, and the second is the behavior of the controlled outputs y in the presence of disturbances.
Abstract: We will consider two different effects of disturbance directions. One is in terms of the magnitude of the manipulated variables m needed to cancel the influence of the disturbance on the process output completely at steady state. It is independent of the controller C. This may be used to identify problems with constraints at steady state. However, the issue of constraints at steady state is not really a control problem, but rather a plant design problem. Any well-designed plant should be able to reject disturbances at steady state. The second and most important effect of disturbance directions is on closed-loop performance. Here we mean by performance the behavior of the controlled outputs y in the presence of disturbances.


Journal ArticleDOI
TL;DR: A novel experimental reactor system with facilities for on-line measurements of polymer quality is employed and it is shown that the multivariable feedback controller is able to track the nominal open-loop optimal state trajectories in the presence of process disturbances.
Abstract: This paper presents a theoretical and experimental analysis of the open- and closed-loop optimal control of a batch reactor for the solution polymerization of methyl methacrylate. A novel experimental reactor system with facilities for on-line measurements of polymer quality is employed to verify the theoretical results. A process control computer is used for on-line data acquisition and implementation of the time optimal policies. These policies are derived by application of the Maximum Principle to a mathematical model of the process. Experimental results show good agreement with theoretical predictions. Optimal closed-loop control policies are also derived and implemented on a simulated reactor model. It is shown that the multivariable feedback controller is able to track the nominal open-loop optimal state trajectories in the presence of process disturbances. Significant economic advantages can be obtained by operating polymerization reactors in an optimal way such that consistent product quality is maintained orland the polymerization time is minimized. The state of the art and the benefits of automation and computer control of polymerization reactors have been discussed in detail in three excellent review papers by Amrehn (1977), Hoogendoorn and Shaw (1980), and MacGregor et al. (1983). Although computer automation has been successfully applied to the polymerization industry over the past 15 years, the progress in computer optimal control of polymerization reactors has been slow. This has been mainly attributed to the lack of robust and reliable on-line polymer characterization devices. In the past, closed-loop control in polymerization reactors was limited to temperature and pressure control. However, with the advent of advanced computer control techniques and the development of new analytical techniques for measurement of polymer quality, the scope of on-line control of polymer

Journal ArticleDOI
TL;DR: The rheology of foam is not like that of simpler fluids which can be regarded as mathematical continua as mentioned in this paper, because the size of foam bubbles is not infinitesimal relative to the width of the flow channels and because foam contains a high volume fraction of the discontinuous phase.
Abstract: The rheology of foam is not like that of simpler fluids which can be regarded as mathematical continua. The difference arises because the size of foam bubbles is not infinitesimal relative to the width of the flow channels and because foam (whether gas-in-liquid or liquid-in-liquid) contains a high volume fraction (in excess of 74% for a monodisperse system) of the discontinuous phase. Special emphasis is given to recent work that evaluates the critical yield stress in idealized cases and makes is possible to relate measured apparent viscosities of foams in large channels to a usually unmeasured boundary effect.

Journal ArticleDOI
TL;DR: In this paper, the dechets en utilisant du propylene-glycol reaction avec de l'anhydride maleique and du styrene are depolymerised.
Abstract: Depolymerisation des dechets en utilisant du propylene-glycol puis reaction avec de l'anhydride maleique et du styrene pour obtenir des polyesters insatures

Book ChapterDOI
TL;DR: In this article, the change of the volatiles burnout time has been investigated for different particle sizes, superficial velocities, volatile matter content and masses charged, and the results have shown that the VOLATILITY takes about 3-12 sec to burn for the particle size(1.52-3.06mm) and velocity range (0.38-0.58m/s) studied.
Abstract: The change of the volatiles burn-out time has been investigated for different particle sizes, superficial velocities, volatile matter content and masses charged. The results have shown that the volatiles take about 3–12 sec to burn for the particle size(1.52–3.06mm) and velocity range (0.38–0.58m/s) studied. The radial velocity of the volatiles coming out of a particle was found to be close to Umf. The surface flux of volatiles increases with particle size. The volatiles affect the combustion characteristics of the remaining char.

Journal ArticleDOI
TL;DR: Etude faite sur l'extraction supercritique avec du CO 2 de pesticides dans le sol (PCB, DDT and Toxaphene) as discussed by the authors.
Abstract: Etude faite sur l'extraction supercritique avec du CO 2 de pesticides dans le sol (PCB, DDT et Toxaphene)

Journal ArticleDOI
TL;DR: The authors compare des vitesses de sulfatation de CaO prepare a partir de carbonate ou d'hydroxyde de calcium; les particules sont assez petites pour eliminer toutes les resistances de transport excepte la diffusion a travers la couche de produit.
Abstract: Comparaison des vitesses de sulfatation de CaO prepare a partir de carbonate ou d'hydroxyde de calcium; les particules sont assez petites pour eliminer toutes les resistances de transport excepte la diffusion a travers la couche de produit

Journal ArticleDOI
TL;DR: In this article, the kinetics of the thermal decomposition of Moroccan oil shale have been studied by isothermal and nonisothermal thermogravimetry (TG), and the non-isothermal weight loss data has been analyzed by using three models, while the isothermal TG data have been correlated by using the integral method of kinetic analysis.
Abstract: The kinetics of the thermal decomposition of Moroccan oil shale have been studied by isothermal and nonisothermal thermogravimetry (TG). The nonisothermal weight loss data have been analyzed by using three models, while the isothermal TG data have been correlated by using the integral method of kinetic analysis. The combined use of nonisothermal and isothermal TG measurements has shown that the thermal decomposition of Moroccan oil shale involves two consecutive reactions with bitumen as an intermediate. The pyrolysis rates of Moroccan shale are compared with those of Colorado and Jordan shale.