Showing papers in "Chemical Engineering Science in 2008"

TL;DR: Zhu et al. as discussed by the authors provided a summary of the studies based on discrete particle simulation in the past two decades or so, with emphasis on the microdynamics including packing/flow structure and particle-particle, particle-fluid and particle wall interaction forces.

TL;DR: In this article, a review of recent advances on chemical-looping combustion (CLC) is presented, which is a promising technology for fossil fuel combustion preventing CO 2 dilution with flue gases, mainly nitrogen.

TL;DR: An overview and critical analysis of the state of the art in this sector are proposed and the main contributions to model-based experiment design procedures in terms of novel criteria, mathematical formulations and numerical implementations are highlighted.

TL;DR: In this article, the authors demonstrate the potential of using a CaO sorbent to enhance hydrogen output from biomass gasifiers and show that CaO materials are the most suitable sorbents reported in the literature for in situ CO 2 capture.

TL;DR: In this paper, the precipitation of different forms of magnesium carbonate has been studied at temperatures between 25 and 120 ∘ C and at a partial pressure of CO 2 between 1 and 100 bar.

TL;DR: In this article, the shape of the interface between the immiscible liquids was controlled by a competition between the viscous forces and the local interfacial tension, and the mass transfer coefficients for parallel and slug flow were determined using instantaneous eutralisation (acidbase) reaction.

TL;DR: In this article, a multi-inlet vortex mixer (MIVM) is proposed to control both the supersaturation and the final solvent quality by varying stream velocities.

TL;DR: It is shown that the PSO method is efficient for both minimization and construction of the confidence region of parameter estimates and that the elliptical approximation of confidence regions of nonlinear model parameters can be very poor sometimes and that more accurate likelihood confidence regions can be constructed with PSO.

TL;DR: In this paper, a doubly stochastic Poisson process is used to analyze the fluctuation characteristics of solid concentration in CFB risers, which provides a mean to define the solid concentration inside clusters.

TL;DR: In this paper, a polyvinylidene fluoride (PVDF) hydrophobic asymmetric hollow fiber membrane was fabricated through the dry-jet wet phase inversion process.

TL;DR: In this article, the effects of surfactant additives on the formation of clathrate hydrate in a quiescent methane/liquid-water system, which was initially composed of a 300 cm3 aqueous phase and an ∼640-cm3 methane-gas phase, was investigated.

TL;DR: In this article, a combination of microscopic imaging, mercury porosimetry and magnetic resonance imaging allowed the determination of the pore sizes, strut diameters, void fractions and geometric surface areas of the foams.

TL;DR: In this paper, the rate constant of CaO-CO 2 reaction was studied for two sorbents using an atmospheric thermogravimetric analyzer (ATGA) and a pressurised TGA, and the activation energies were 29 ± 4 and 24 ± 6 kJ / mol for the limestone and dolomite tested.

TL;DR: A critical review of the literature on hydrate kinetics is provided in this article, with special emphasis upon modeling efforts, essential to the design of any reactor, and the main features of the models available in the literature for hydrate nucleation and growth are discussed, together with their limitations.

TL;DR: In this article, a number of tangential force-displacement models are reviewed including linear models by Cundall and Strack [1979], Brendel and Dippel [1998] and Di Renzo and Di Maio [2005].

TL;DR: In this article, the authors investigated the parameters affecting the discharge rate using the discrete element method (DEM) and compared the results with previously published experimental correlations, showing that the results indicate that DEM simulations are fully capable of reproducing trends in discharge rate that are well-known experimentally.

TL;DR: In this paper, a comprehensive CFD model was developed to gain an insight into solid suspension and its implications on the liquid-phase mixing process in a solid-liquid stirred reactor, where the turbulent solid liquid flow was simulated using a two-fluid model with the standard k-e turbulence model with mixture properties.

TL;DR: In this article, a complete mathematical model that describes the dynamic behaviour of a PSA unit is presented, which is applied in the study of both single column and four columns PSA processes with layered activated carbon/zeolite beds and with an eight steps cycle.

TL;DR: In this paper, a review of two-fluid nozzle designs and principles together with a presentation of nozzle fundamentals introducing basic nozzle theory and thermodynamics are presented. And the relationship between the prediction of mean droplet diameters and their use is discussed, compared and accompanied by a discussion of their use.

TL;DR: In this article, the effect of subgrid scales on the resolved scales has been modeled by dynamic one equation subgrid-scale model and the simulated values of the mean axial, radial and tangential velocities along with the turbulent kinetic energy have been compared with the measured LDA data.

TL;DR: In this article, a computational fluid dynamics (CFD)-code has been developed using finite volume method in Eulerian framework for the simulation of axisymmetric steady state flows in bubble columns.

TL;DR: In this article, a semi-empirical density-based model for supercritical carbon dioxide solubility was proposed. But the model is not suitable for the case where the reduced density of the solvent is below 1.

TL;DR: In this article, the geometry of the domain can constrain wormhole competition and influence wormhole dynamics in a core submitted to acidizing, and the authors conclude that wormholing is not a full-scale independent process.

TL;DR: In this article, a high pressure differential scanning calorimeter (DSC) was used to measure the methane hydrate heat of dissociation (H→W+G), Δ H d, which was shown to be in agreement with the Clausius-Clapeyron equation predictions at high pressures.

TL;DR: Modulation excitation spectroscopy (MES) as mentioned in this paper allows sensitive and selective detection and monitoring of the dynamic behavior of species directly involved in a reaction and is powerful for elucidating complex systems and noisy data.

TL;DR: In this paper, a series of numerical simulations performed on the microstructure of a real fibrous media is presented for reconstructing 3D images from the 2D images of the real fiber and processing them for the purpose of performing fluid flow simulation.

TL;DR: In this article, the authors describe two-phase flow pattern and pressure drop characteristics during the absorption of CO2 into water in three horizontal microchannel contactors which consist of Y-type rectangular microchannels having hydraulic diameters of 667, 400 and 200 mu m, respectively.

TL;DR: In this article, PdCl 2 / SBA-15 showed the highest capacity of selective sulfur adsorption among all known sorbents, and the significant breakthrough occurred at about 50.0 ml/g for desulfurization of JP-5 light fraction.

TL;DR: In this paper, wood chips and wood pellets were fired together with straw pellets, while the tendency to agglomerate and form deposits was monitored, and a number of countermeasures were applied in related tests.

TL;DR: In this paper, the accuracy of the focused beam reflectance measurement (FBRM) probe, which measures a chord length distribution, from Mettler-Toledo Lasentec ® has been explored.