Showing papers in "Chemical Engineering Journal in 1998"

TL;DR: In this paper, the sorption of two dyes, namely Basic Blue 69 and Acid Blue 25 onto peat has been studied in terms of pseudo-second order and first order mechanisms for chemical sorption as well as an intraparticle diffusion mechanism process.

TL;DR: In this paper, a two-step hydrate formation mechanism is proposed for gas hydrate, which consists of a quasi-chemical reaction process to form basic hydrate and an adsorption process of smaller gas molecules in the linked cavities of basic hydrates.

TL;DR: In this paper, two types of commercial maize starch were used: a normal maize with 30% amylose and a waxy maize consisting mainly of amylopectin, and the results from transient flow property measurements using a concentric cylinder viscometer show that the starch pastes are strongly thixotropic and shear thinning as characterised by a viscosity that decreases with time and rate of shear.

TL;DR: In this article, the Kenics static mixer was investigated numerically using Lagrangian methods, to characterize mixer performance in laminar flow and the results showed that mixing performance is independent of Re.

TL;DR: In this paper, a modular form of ion exchange resin capable of effective exchange with metal ions in solution was produced by incorporating Na + ions onto the sulphonated polyhipe polymer surfaces.

TL;DR: The proposed techniques are applied to the simulation studies of a batch methylmethacrylate polymerisation reactor and can be used to design optimal batch recipes and to monitor polymerisation processes.

TL;DR: In this paper, concentrated suspensions of coarse SiO2 particles containing various amounts of fine TiO2 have been studied using a viscometer which prevents settling of the suspended material.

TL;DR: It is found that the results obtained are comparable to those obtained from the traditional methods published in the literature, and the proposed method is computationally efficient and is readily applicable as a method for design and control of network systems.

TL;DR: In this paper, a one-dimensional model of reaction, diffusion and mixing in a two-dimensional flow is presented, where initially segregated reactants are stretched and folded into a lamellar structure.

TL;DR: In this paper, a model of the lower operating limits of distillation and absorption trays is described, which requires the simultaneous solution of two equations describing (1) liquid flow across the tray and over the outlet weir, and (2) countercurrent liquid flow through the free hole area of the tray.

TL;DR: In this paper, a numerical model for the gas-particle flow dynamics has been combined with a NOx chemistry post-processor to predict the formation of nitric oxide in a three-dimensional, W-shaped boiler furnace burning pulverized fuel.

TL;DR: In this paper, the impact of inclination on the drop sizes has been investigated and the difference in drop sizes obtained from two laser systems when measurements were made under similar flow conditions was identified and a technique was suggested to modify the new data obtained from the phase Doppler anemometry.

TL;DR: In this paper, a two-dimensional pseudo-two-phase fluid dynamic model with included turbulence model was used to calculate local values of axial liquid velocity and gas holdup in a concurrent gas-liquid-solid three-phase bubble column reactor.

TL;DR: In this paper, the average rate of heat transfer as well as the oscillatory spanwidths of the Nusselt number and the Rayleigh number were measured for natural convection in a layer of liquid gallium (Pr = 0.023) heated from below electrically and cooled from above with running water.

TL;DR: In this paper, the limiting flux of untreated starfruit juice obtained during clarification using membrane ultrafiltration was analyzed using the gel model, and the observed deviation from the model was mainly due to the high pectin content of the juice.

TL;DR: In this article, a mathematical model for describing the decomposition and removal of binder from ceramic components formed by injection molding is developed, which takes into account heat transfer by conduction within the ceramic body, mass transfer by convective flow of gas products, and an Arrhenius dependence of decomposition rate.

TL;DR: A distributed parameter model for photocatalytic oxidation of air contaminants in monolith reactors is presented in this paper, where heat and mass balance equations for monolith structure are combined with a model of irradiation from a light source and a kinetic model for photon adsorption and chemical reaction to describe the processes of heat, mass and photon transfer within the system.

TL;DR: In this article, the flow hydrodynamics (flow structure, velocity fields, flow energy parameters etc.) are studied related to the geometrical parameters of the internals and to pulsation intensity.

TL;DR: In this paper, the effect of laminar micromixing on parallel reactions was studied experimentally and interpreted theoretically using a new model of LMM, developed by applying an integral transformation to material balance equations in the Lagrangian frame of reference.

TL;DR: In this article, the extraction and back-extraction of nickel and cadmium were carried out simultaneously in a batch mode using two parallel modules and the organic phase flowing in a closed circuit.

TL;DR: In this article, a model consisting of three-directional mass, momentum and energy balances was proposed for a low-Prandtl-number fluid, and the transient response after a step increase of lower-wall temperature was at first a regular oscillation, which then evolved to a series of long rolls with their axes in one direction.

TL;DR: In this article, a mathematical model for riser liquid superficial velocity in a concentric-tube air-lifted reactor is proposed based on an energy balance incorporating acceleration coefficients to quantify deviations from ideal flow.

TL;DR: In this article, a comprehensive one-dimensional model was developed for the simulation of a riser regenerator, which incorporates hydrodynamic characteristics of fluidized bed risers and the detailed reaction kinetics of FCC (fluid catalytic cracking) catalyst regeneration and can be used to predict the axial profiles of temperature, oxygen concentration and coke content of the catalyst in the riser.

TL;DR: The kinetic and equilibrium constants for the Chromatographie enantioseparation of racemic propranolol, using cellulosetri(3,5-dimethyl-phenylcarbamate) as the chiral stationary phase and hexane and isopropanol as the mobile phase, were evaluated by moment analysis on the basis of equilibrium-dispersive and linear driving force models.

TL;DR: In this paper, the role of mass transfer in the kinetics of flow induced corrosion of agitated vessels impellers was investigated using the diffusion controlled dissolution of copper in acidified chromate technique.

TL;DR: In this paper, the results obtained from this study can be used directly to predict vapor-liquid equilibria involving such systems, and they have been observed that the non-random two liquid (NRTL) model provides a good representation of G E models, in spite of the asymmetry inherent to these systems.

TL;DR: In this paper, an engineering model of the catalytic partial oxidation of methane in a fluidized-bed reactor developed on the basis of experimental data obtained in a laboratory unit (ID = 5 cm) over a Ni/α-Al 2 O 3 catalyst was presented.

TL;DR: In this paper, the authors used a pilot-plant scale McInnis-Bischoff variable throat venturi scrubber with variable ranges that are normally encountered with industrial size units.

TL;DR: In this paper, a model for the mass-transfer-controlled spherical bubble growth in a quiescent liquid is presented, where the liquid is of variable diffusion coefficient, which depends exponentially on the concentration.

TL;DR: In this paper, the influence of agitation rate on scaling in a turbine-agitated tank was examined using constant temperature anemometry measurements, and it was found that changing the agitation rate affects flow conditions in the impeller zone more than in the bulk zone.