Showing papers in "Industrial & Engineering Chemistry Research in 1988"

An improved equation for predicting the solubility of vegetable oils in supercritical carbon dioxide

Abstract: On presente une version amelioree de l'equation de Chrastil permettant d'evaluer la solubilite des huiles vegetales dans CO 2 comprime

Chemistry of olefin oligomerization over ZSM-5 catalyst

Abstract: La composition et la masse moleculaire des produits obtenus dependent beaucoup de la pression et de la temperature

The role of temperature in the fast pyrolysis of cellulose and wood

Abstract: Cellulose and maple sawdust have been pyrolyzed by different workers in two different reactors (a fluid bed and a transport reactor) in separate laboratories. The Avicel cellulose sample used by both groups was from the same batch, while the maple was different samples of the same species. Fast pyrolysis product yields were compared at a constant vapor residence time of 500 ms over a temperature range of 450-900/sup 0/C and were found to be in very good agreement. It is proposed that if particle heat-up time to 500/sup 0/C, for any reactor, is significantly less than particle residence time, or if particle weight loss is less than 10% before the particle temperature reaches 450/sup 0/C, then the temperature of the reactor will be the only variable determining the yields of char, oil, and gases for a given feed material and a given gas residence time. The implications of the results in terms of product yields and possible pyrolysis mechanisms are discussed. The oil yield as temperature increases can be described adequately by a simple kinetic model.

Understanding the Dynamic Behavior of Distillation Columns

Abstract: Mise en place d'un modele a deux constantes de temps en tenant compte des changements d'ecoulement internes et externes

Preparation and characterization of early transition metal carbides and nitrides

Abstract: Synthese a temperature programmee dans un courant de gaz reactif. Proprietes physicochimiques

Wet oxidation catalyzed by ruthenium supported on cerium(IV) oxides

Abstract: The activity of precious meta catalysts in the wet oxidation of organic compounds was investigated. Ruthenium was the most active catalyst among the precious metals examined, and cerium (IV) oxide was the most effective support. The Ru/Ce catalyst rivaled homogeneous copper catalyst, which is used in the practical wastewater treatment, for the oxidation of n-propyl alcohol, n-butyl alcohol, phenol, acetamide, poly (propylene glycol), and acetic acid. In addition, it was especially effective for the oxidation of some compounds with high oxygen content such as poly (ethylene glycol), ethylene glycol, formaldehyde, and formic acid.

Predictive model and experimental results for a two-adsorber solid adsorption heat pump

Abstract: L'etude experimentale est realisee avec le systeme eau-zeolite NaX. On obtient un bon accord entre les resultats experimentaux et le modele mathematique. On etudie trois cas de couplage entre la pompe a chaleur et les sources de chaleur exterieures: couplage indirect avec contrainte d'energie (chauffage de l'adsorbeur et refroidissement du condenseur) couplage direct avec contrainte de temperature (evaporateur); et couplage indirect avec contrainte de temperature (refroidissement des adsorbeurs)

Analysis and modeling of the direct sulfation of CaCO3

Abstract: Les vitesses elevees pour la sulfatation directe sont dues a la formation d'une couche poreuse de sulfate de Ca

Performance of an internal direct-oxidation carbon fuel cell and its evaluation by graphic exergy analysis

Abstract: An internal direct-oxidation carbon fuel cell was operated to evaluate its characteristics. The cell electrolyte was a yttria-stabilized zirconia disk of 1.5-mm thickness. It had 2.0-cm/sup 2/ platinum porous electrodes on both of the surfaces. In the fuel chamber, charcoal was put as raw fuel and gasified by oxygen permeated from the air chamber. It was operated at 1075, 1180, and 1275 K under atmospheric pressure, and its performance was analyzed from the viewpoint of exergy by using the energy-utilization diagram, assuming uniform gas composition in both the air chamber and the fuel chamber. On this diagram, exergy losses caused by electrode polarization, gasification, and ohmic loss were represented. The relation between the electric power obtained and the exergy loss in each subsystem was disclosed by examining the amount and level of the energy transformed.

Feedforward and feedback linearization of nonlinear system and its implementation using internal model control (IMC)

Abstract: Cette strategie, presentee ici theoriquement est appliquee au cas d'un reacteur parfaitement agite

Desorption of ethyl acetate from activated carbon by supercritical carbon dioxide

Abstract: Etude experimentale de l'extraction par fluide super critique du compose du titre et mise en place d'un modele mathematique a un parametre. On etudie l'influence de la temperature et de la pression sur la regeneration de l'adsorbant

The use of biased least-squares estimators for parameters in discrete-time pulse-response models

Abstract: On utilise deux methodes d'approche: la methode des moindres carres partiels et une methode basee sur la decomposition de la valeur singuliere. Un exemple de station de traitement anaerobique des eaux usees est presente

Catalytic SOx abatement: the role of magnesium aluminate spinel in the removal of SOx from fluid catalytic cracking (FCC) flue gas

Abstract: A cerium-containing magnesium aluminate spinel catalyst is used as a SO/sub x/ emission reducing catalyst in the hydrocarbon cracking catalyst regeneration zone. In the regeneration zone, this catalyst oxidizes the SO/sub 2/ to SO/sub 3/, chemisorbs it as sulfate, and releases it as H/sub 2/S when it enters the reactor zone. All FCC units are equipped to handle the H/sub 2/S that comes out of the reactor. This paper discusses some of the materials, such as the cerium-containing spinels, that were examined as potential SO/sub x/ catalysts for FCC units and how they were tested for their ability to remove SO/sub x/ under conditions prevalent in modern FCC units.

Process control strategies for constrained nonlinear systems

Abstract: Les problemes de contrainte des variables d'etat et de commande sont traites a l'aide d'une forme speciale de programmation quadratique successive

Catalytic membrane for simultaneous chemical reaction and separation applied to a dehydrogenation reaction

Abstract: Le reacteur a membrane catalytique (une membrane de verre vycor microporeux impregne de platine) est utilise pour la deshydrogenation du cyclohexane en benzene. Les resultats experimentaux ainsi que ceux issus d'une simulation montrent que ce type de reacteur est plus performant qu'un reacteur a membrane inerte avec un garnissage de particules catalytiques

Kinetic modeling of the thermal cracking of hydrocarbons. 1. Calculation of frequency factors

Abstract: Le modele cinetique est developpe pour le craquage thermique de fractions petrolieres legeres. Les mecanismes de reaction mettent en jeu des radicaux libres. Pour chaque reaction l'entropie standard du complexe active est determine par la thermodynamique statistique. Le facteur de frequence est calcule a partir des donnees de la theorie de l'etat stationnaire

Catalytic hydrotreatment of vacuum pyrolysis oils from wood

Abstract: Etude de l'influence du pretraitement par hydrogenation en conditions moderees en presence de catalyseur Ru, sur l'hydrodesoxygenation d'une huile de pyrolyse sous vide du bois