Modeling of three-phase continuously operating open-cell foam catalyst packings: sugar hydrogenation to sugar alcohols

An advanced comprehensive and transient multiphase model for a trickle bed reactor with solid foam packings was developed. A new simulation model for isothermal three-phase (gas–liquid–solid) catalytic tubular reactor models was presented where axial, radial and catalyst layer effects were included. The gas, liquid and solid phase mass balances included most of the individual terms for solid foam packing (e.g. kinetics, liquid-solid and intraparticle mass transfer effects). Hydrogenation of arabinose and galactose mixture on a ruthenium catalyst supported by carbon-coated aluminum foams was applied as a fundamentally and industrially relevant case study. Parameter estimations allowed to obtain reliable and significant parameters. To test the model performance, a sensitivity analysis was performed and the effect of the kinetic parameters and the operation conditions on the arabinose and galactose conversions was studied in detail. The model described here is applicable for other three-phase continuous catalytic reactors with solid foam packings.

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Experimental characterization of the solid phase chaotic dynamics in three-phase fluidization

International Journal of Multiphase Flow ◽

10.1016/s0301-9322(97)88294-8 ◽

1996 ◽

Vol 22 ◽

pp. 113

Author(s):

M Cassanello

Keyword(s):

Chaotic Dynamics ◽

Solid Phase ◽

Experimental Characterization ◽

Three Phase

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CFD Simulation of Solid Suspension for a Liquid–Solid Industrial Stirred Reactor

Applied Sciences ◽

10.3390/app11125705 ◽

2021 ◽

Vol 11 (12) ◽

pp. 5705

Author(s):

Adrian Stuparu ◽

Romeo Susan-Resiga ◽

Alin Bosioc

Keyword(s):

Chemical Reaction ◽

Cfd Simulation ◽

Simulation Analysis ◽

Solid Phase ◽

Initial Conditions ◽

Chemical Reactor ◽

Liquid Mixtures ◽

Multiphase Model ◽

Chemical Product ◽

Two Phase

The present study examines the possibility of using an industrial stirred chemical reactor, originally employed for liquid–liquid mixtures, for operating with two-phase liquid–solid suspensions. It is critical when obtaining a high-quality chemical product that the solid phase remains suspended in the liquid phase long enough that the chemical reaction takes place. The impeller was designed for the preparation of a chemical product with a prescribed composition. The present study aims at finding, using a numerical simulation analysis, if the performance of the original impeller is suitable for obtaining a new chemical product with a different composition. The Eulerian multiphase model was employed along with the renormalization (RNG) k-ε turbulence model to simulate liquid–solid flow with a free surface in a stirred tank. A sliding-mesh approach was used to model the impeller rotation with the commercial CFD code, FLUENT. The results obtained underline that 25% to 40% of the solid phase is sedimented on the lower part of the reactor, depending on the initial conditions. It results that the impeller does not perform as needed; hence, the suspension time of the solid phase is not long enough for the chemical reaction to be properly completed.

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A framework ensemble facilitates high Pt utilization in a low Pt loading fuel cell

Catalysis Science & Technology ◽

10.1039/d1cy00028d ◽

2021 ◽

Vol 11 (8) ◽

pp. 2957-2963

Author(s):

Jian Wang ◽

Guangping Wu ◽

Wenhui Xuan ◽

Lishan Peng ◽

Yong Feng ◽

...

Keyword(s):

Fuel Cell ◽

Phase Field ◽

Active Sites ◽

Catalyst Layer ◽

Three Phase ◽

Pt Utilization ◽

The Cross ◽

Low Pt Loading ◽

Effective Transfer

Rationally designing the structure of catalyst layer in MEA to achieve the dispersion of active sites at the cross of three-phase field and the effective transfer network paths for protons through catalysts and catalyst layer.

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Geometric Algebra Framework Applied to Symmetrical Balanced Three-Phase Systems for Sinusoidal and Non-Sinusoidal Voltage Supply

Mathematics ◽

10.3390/math9111259 ◽

2021 ◽

Vol 9 (11) ◽

pp. 1259

Author(s):

Francisco G. Montoya ◽

Raúl Baños ◽

Alfredo Alcayde ◽

Francisco Manuel Arrabal-Campos ◽

Javier Roldán Roldán Pérez

Keyword(s):

Geometric Algebra ◽

Dimensional Euclidean Space ◽

Active Components ◽

Electrical Circuits ◽

Current Harmonics ◽

Operation Conditions ◽

Multiple Phase ◽

Three Phase ◽

Phase Systems ◽

Definition Of

This paper presents a new framework based on geometric algebra (GA) to solve and analyse three-phase balanced electrical circuits under sinusoidal and non-sinusoidal conditions. The proposed approach is an exploratory application of the geometric algebra power theory (GAPoT) to multiple-phase systems. A definition of geometric apparent power for three-phase systems, that complies with the energy conservation principle, is also introduced. Power calculations are performed in a multi-dimensional Euclidean space where cross effects between voltage and current harmonics are taken into consideration. By using the proposed framework, the current can be easily geometrically decomposed into active- and non-active components for current compensation purposes. The paper includes detailed examples in which electrical circuits are solved and the results are analysed. This work is a first step towards a more advanced polyphase proposal that can be applied to systems under real operation conditions, where unbalance and asymmetry is considered.

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Influence of biomass on hydrodynamics of an internal loop airlift reactor

Chemical Papers ◽

10.2478/s11696-006-0080-2 ◽

2006 ◽

Vol 60 (6) ◽

Cited By ~ 1

Author(s):

M. Juraščík ◽

M. Hucík ◽

I. Sikula ◽

J. Annus ◽

J. Markoš

Keyword(s):

Aspergillus Niger ◽

Gluconic Acid ◽

Solid Phase ◽

Biomass Concentration ◽

Airlift Reactor ◽

Phase System ◽

Two Phase ◽

Experimental Conditions ◽

Internal Loop ◽

Three Phase

AbstractThe effect of the biomass presence on the overall circulation velocity, the linear velocities both in the riser and the downcomer and the overall gas hold-up was studied in a three-phase internal loop airlift reactor (ILALR). The measured data were compared with those obtained using a two-phase system (air—water). All experiments were carried out in a 40 dm3 ILALR at six different biomass concentrations (ranging from 0 g dm−3 to 7.5 g dm−3), at a temperature of 30°C, under atmospheric pressure. Air and water were used as the gas and liquid model media, respectively. Pellets of Aspergillus niger produced during the fermentation of glucose to gluconic acid in the ILALR were considered solid phase. In addition, liquid velocities were measured during the fermentation of glucose to gluconic acid using Aspergillus niger. All measurements were performed in a bubble circulation regime. At given experimental conditions the effect of the biomass on the circulation velocities in the ILALR was negligible. However, increasing of the biomass concentration led to lower values of the total gas hold-up.

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Gas hold-up in a three-phase reciprocating plate column

Journal of the Serbian Chemical Society ◽

10.2298/jsc0511363n ◽

2005 ◽

Vol 70 (11) ◽

pp. 1363-1371 ◽

Cited By ~ 2

Author(s):

Ljubisa Nikolic ◽

Vesna Nikolic ◽

Vlada Veljkovic ◽

Dejan Skala

Keyword(s):

Solid Phase ◽

Liquid System ◽

Column Diameter ◽

Gas Velocity ◽

Vibration Intensity ◽

Three Phase ◽

Superficial Gas Velocity ◽

Phase Column ◽

Plate Column ◽

Good Agreement

The influence of the geometry of a reciprocating plate column (diameter), superficial gas velocity, vibration intensity and content of the solid phase in the column on the gas hold-up in a three phase column (G-L-S) were investigated in this study. For comparison, the gas hold-up was also analyzed in a gas-liquid system (G-L) in the same type of column. Good agreement between the experimentally determined values of the gas hold-up and those calculated on the basis of the derived correlation for the G-L and G-L-S system was obtained.

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Measurement of the local velocity of the solid phase and the local solid hold-up in a three-phase flow by X-ray based particle tracking velocimetry (XPTV)

Chemical Engineering Science ◽

10.1016/s0009-2509(03)00010-1 ◽

2003 ◽

Vol 58 (9) ◽

pp. 1721-1729 ◽

Cited By ~ 25

Author(s):

A Seeger ◽

U Kertzscher ◽

K Affeld ◽

E Wellnhofer

Keyword(s):

Particle Tracking ◽

Particle Tracking Velocimetry ◽

Solid Phase ◽

Phase Flow ◽

Local Velocity ◽

X Ray ◽

Three Phase ◽

Three Phase Flow

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Precise Electrochemical Testing in Half-Cells: Controlling Catalyst Layer Formation and the Three-Phase Boundary in Gas Diffusion Electrodes

ECS Meeting Abstracts ◽

10.1149/ma2021-02361071mtgabs ◽

2021 ◽

Vol MA2021-02 (36) ◽

pp. 1071-1071

Author(s):

Rameshwori Loukrakpam Jalan ◽

Bruna Ferreira Gomes ◽

Christina Roth

Keyword(s):

Phase Boundary ◽

Catalyst Layer ◽

Gas Diffusion ◽

Layer Formation ◽

Gas Diffusion Electrodes ◽

Electrochemical Testing ◽

Three Phase ◽

Three Phase Boundary

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Multiphase Reactions and Reactors

Organic Synthesis Engineering ◽

10.1093/oso/9780195096897.003.0025 ◽

2001 ◽

Author(s):

L. K. Doraiswamy

Keyword(s):

Liquid Phase ◽

Solid Phase ◽

Complete Classification ◽

Catalytic Reactions ◽

Two Phase ◽

Multiphase Reactions ◽

Liquid Phases ◽

Three Phase ◽

Solid Form

The first three chapters of this part dealt with two-phase reactions. Although catalysts are not generally present in these systems, they can be used in dissolved form in the liquid phase. This, however, does not increase the number of phases. On the other hand, there are innumerable instances of gas-liquid reactions in which the catalyst is present in solid form. A popular example of this is the slurry reactor so extensively employed in reactions such as hydrogenation and oxidation. There are also situations where the solid is a reactant or where a phasetransfer catalyst is immobilized on a solid support that gives rise to a third phase. A broad classification of three-phase reactions and reactors is presented in Table 17.1 (not all of which are considered here). This is not a complete classification, but it includes most of the important (and potentially important) types of reactions and reactors. The thrust of this chapter is on reactions and reactors involving a gas phase, a liquid phase, and a solid phase which can be either a catalyst (but not a phasetransfer catalyst) or a reactant, with greater emphasis on the former. The book by Ramachandran and Chaudhari (1983) on three-phase catalytic reactions is particularly valuable. Other books and reviews include those of Shah (1979), Chaudhari and Ramachandran (1980), Villermaux (1981), Shah et al. (1982), Hofmann (1983), Crine and L’Homme (1983), Doraiswamy and Sharma (1984), Tarmy et al. (1984), Shah and Deckwer (1985), Chaudhari and Shah (1986), Kohler (1986), Chaudhari et al. (1986), Hanika and Stanek (1986), Joshi et al. (1988), Concordia (1990), Mills et al. (1992), Beenackers and Van Swaaij (1993), and Mills and Chaudhari (1997). Doraiswamy and Sharma (1984) also present a discussion of gas-liquid-solid noncatalytic reactions in which the solid is a reactant. In Chapter 7 we saw how Langmuir-Hinshelwood-Hougen-Watson (LHHW) models are normally used to describe the kinetics of gas-solid (catalytic) or liquid-solid (catalytic) reactions, and in Chapters 14 to 16 we saw how mass transfer between gas and liquid phases can significantly alter the rates and regimes of these two-phase reactions.

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