Showing papers in "Chemical Engineering Science in 1995"

TL;DR: In this article, the authors proposed a method to predict the distribution of residence-times in large systems by using distribution-functions for residencetimes, which can be used to calculate the etficiencies of reactors and blenders.

TL;DR: In this paper, the equations governing spherically symmetric phase growth in an infinite medium are first formulated for the general case and then simplified to describe growth controlled by the transport of heat and matter.

TL;DR: In this article, a rate theory for band broadening in linear, non-ideal chromatography is presented, wherein nonideality is caused by axial molecular diffusion, axial eddy diffusion, and finiteness of transfer coefficient.

TL;DR: In this paper, the Peclet number is used as the similarity criterion for longitudinal mixing of fluids in flow, which is analogous to and has the same units as the coefficient of molecular diffusion.

TL;DR: In this paper, new collocation methods are given for solving symmetrical boundary-value problems, where orthogonality conditions are used to select the collocation points and the accuracy obtained is comparable to that of least squares or variational methods and the calculations are simpler.

TL;DR: In this paper, a comprehensive model is developed for the absorption of carbon dioxide into aqueous mixtures of primary or secondary alkanolamines with tertiary alkanolamines, which incorporates an extensive set of important reversible reactions and takes into account the coupling between chemical equilibrium, mass transfer and chemical kinetics.

TL;DR: In this paper, the authors provided accurate numerical values for the solution of the diffusion model of miscible fluid displacement in beds of finite length, where a solute, uniformly distributed throughout the medium at the outset of the experiment, is displaced by a solvent which may itself contain some of the solute.

TL;DR: In this paper, the main mass transfer parameters, such as bubble size and shape, bubble velocity, and volume fraction of gas inside capillaries of circular or square cross section, were predicted on the basis of the superficial flow rates of gas and liquid in the feed.

TL;DR: In this paper, a continuous and gradual Hopper filling method was introduced, a more realistic normal-tangential interaction between the particles, particle size polydispersity, and the model was extended from two to three dimensions (3D).

TL;DR: In this paper, the boundary conditions for a steady-state flow reactor with axial diffusion and first order reaction were analyzed and the results regarding reactor properties were reached as the result of simultaneous solution of the three differential equations for the reaction section, fore and after sections.

TL;DR: Theoretical and empirical approaches to the fluid dynamic description of liquid fluidized beds are reviewed, together with the relevant experimental evidence as mentioned in this paper, with one section devoted to binary-solid systems, the particles differing in size and/or in density.

TL;DR: The reactivity behavior of porous catalyst particles subject to both internal mass concentration gradients as well as temperature gradients, in endothermic or exothermic reactions has been analyzed in this article.

TL;DR: In this paper, the mechanism and kinetics of the reaction between CO2 and aqueous solution of sterically hindered amine, 2-amino-2-methyl-1-propanol (AMP), were investigated at 294-318 K by gas absorption studies using a wetted wall column.

TL;DR: In this paper, the authors evaluated two-phase heat exchangers for single-phase flows and showed that they can achieve state-of-the-art performance in terms of heat transfer.

TL;DR: In this paper, experimental data on the heat transfer performance of a periodically baffled tube subject to both steady (net) flow and oscillatory flow was reported. But the authors did not consider the effect of the superposition of fluid oscillations.

TL;DR: In this paper, a mean-size foam-bubble conservation equation, along with the traditional reservoir/groundwater simulation equations, provides the foundation for the mechanistic foam-displacement simulations.

TL;DR: In this paper, a set of composition variables for treating phase equilibria in multicomponent, multi-reaction systems with or without inert components present was introduced. And the phase diagrams for complex reacting mixtures were greatly simplified when represented in terms of these new variables.

TL;DR: In this article, a general mixing-precipitation model describing interactions between mixing of various scales (macro-, meso- and micromixing) coupled with the population balance for crystallization is presented.

TL;DR: In this paper, the authors present a new methodology which employs physicochemical properties and their relationships to separation techniques for design and synthesis of separation processes, which covers a wide range of separation problems and consists of selection and identification of separation techniques and corresponding separation tasks, the sequencing of the separation tasks and the determination of appropriate and consistent conditions of operation.

TL;DR: In this paper, a frequency sampling filter model is used to represent the dynamic linear element and a simple least-squares algorithm is applied to simultaneously estimate the parameters of the linear subsystem and the inverse static nonlinearity.

TL;DR: In this article, a model for the evaporation of droplets of multicomponent liquids in which the mixture composition, properties and vapour-liquid equilibrium are described by the methods of continuous thermodynamics is presented.

TL;DR: In this article, the authors proposed a method of determining working illuminated volume defined as the photobioreactor volume with sufficient radiant light energy for microorganism growth, which enables the coupling between radiant light transfer and growth kinetics to be easily studied.

TL;DR: In this article, the authors analyzed the adequacy of lumped models of catalytic combustors by comparison with the more detailed and numerically expensive distributed ones, and pointed out that the results showed that, for long enough monolith segments, gas exit temperatures predicted by one-dimensional models compare well with those provided by distributed models.

TL;DR: In this paper, numerical schemes based on random walks or on a finite difference formulation are described; they take into account convection, diffusion, dissolution and geometrical variations of the porous media.

TL;DR: Decision-mapping, as a rigorously established technique, is directly applicable in developing efficient and exact process synthesis methods or improving existing methods and is illustrated by synthesizing a large scale process.

TL;DR: In this paper, an experimental investigation has been carried out to quantify the wall effect on porosity for uniform spheres packed in cylindrical containers and the results indicate that the side wall effect should be composed of two components: the top-bottom wall effect or the thickness effect, and accurate determination of porosity and/or porosity-related properties should consider both of them.

TL;DR: In this paper, a phenomenological analysis has been developed to relate the wetting efficiency with operating conditions such as reactor pressure, gas and liquid flow rate, which can be expressed by the following correlation: ƞ CE = 1.104 REL 1/3 1 + [( ΔP Z )/p L g] Ga L 1/9

TL;DR: In this article, a rigorous, dynamic mathematical model for predicting the rate of ultrafiltration of charged colloidal dispersions is developed based on sophisticated descriptions of the particle-particle interactions within filter cakes which are responsible for controlling permeation rates.

TL;DR: In this article, a Taylor vortex reactor was designed, constructed and tested as a novel photocatalytic reactor that incorporated illumination and dark recovery times via fluid mixing, and the photoefficiency in the reactor increased by nearly a factor of three with the optimal conditions of an inner cylinder rotation rate of 300 rpm and an unusually high weight loading of 10 g/l of TiO 2 photocatalyst.

TL;DR: In this article, a wetted-sphere absorber was used to acquire kinetic data for the aqueous phase reaction between CO2 and N-methyldiethanolamine (MDEA), and three different mathematical models were developed and used to estimate the forward rate coefficient of the MDEA-catalyzed hydrolysis of CO2 reaction.